PHOTO

Tomoyuki Yambe
Section
Institute of Development, Aging and Cancer
Job title
Professor
Degree
  • 医学博士(東北大学)

Research History 6

  • 2004/01 - Present
    Tohoku University Institute of Development, Aging and Cancer professor

  • 1999/01 - 2003/12
    Tohoku University Institute of Development, Aging and Cancer

  • 1996/01 - 1998/12
    Tohoku University Institute of Development, Aging and Cancer Assistane Professor

  • 1992/08 - 1996/12
    東北大学 Institute of Tuberculosis and Cancer Assistant Professor

  • 1990/01 - 1992/07
    仙台厚生病院

  • 1989/04 - 1990/01
    東北厚生年金病院

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Education 2

  • Tohoku University Graduate School of Medicine

    - 1989/03

  • Tohoku University Faculty of Medicine

    - 1985/03/31

Committee Memberships 6

  • 日本人工臓器学会 理事

    2007/01 - Present

  • 日本生体医工学会 理事

    2007/01 - Present

  • 日本自律神経学会 評議員

    2007/01 - Present

  • 日本人工臓器学会 理事

    2007/01 - Present

  • 日本生体医工学会 理事

    2007/01 - Present

  • 日本自律神経学会 評議員

    2007/01 - Present

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Professional Memberships 4

  • 日本統合医療学会(2012/01- 2017/12)

    2012/01 - 2017/12

  • 日本自律神経学会(2007/01- 評議員)

  • 日本生体医工学会(2007/01- 理事)

  • 日本人工臓器学会(2007/01- 理事)

Research Areas 3

  • Life sciences / Respiratory surgery / Artificial Organs

  • Life sciences / Cardiovascular surgery / Artificial Organs

  • Life sciences / Cardiology / Cardiovascular melicine

Papers 426

  1. Development and initial performance of a miniature axial flow blood pump using magnetic fluid shaft seal.

    Eiji Okamoto, Tetsuya Yano, Kazumitsu Sekine, Yusuke Inoue, Yasuyuki Shiraishi, Tomoyuki Yambe, Yoshinori Mitamura

    Journal of artificial organs : the official journal of the Japanese Society for Artificial Organs 26 (1) 12-16 2023/03

    DOI: 10.1007/s10047-022-01330-7  

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    In this study, we developed a new catheter-mounted micro-axial flow blood pump (MFBP) using a new miniature magnetic fluid shaft seal (MFSS). The prototype of the catheter-mounted MFBP had a maximum diameter of 8 mm and a length of 50 mm. The new MFSS composed a neodymium magnet ring, an iron ring, and a magnetic fluid particularly designed for the MFSS. The new MFSS had outer and inner diameters of 4.0 mm and 2.6 mm, respectively, and a length of 3.0 mm. The sealing pressure of the MFSS was calculated to be 432 mmHg using FEM (Finite Element Method) result; therefore, the MFSS had sufficient sealing pressure for the catheter-mounted MFBP. The friction loss of the MFSS included the friction owing to the viscosity of the magnetic fluid and the magnetic force between the iron ring and ring magnet. The total friction loss of the MFSS was 0.08-0.09 W in the pump operational speed range from 22,000 to 35,000 rpm. From the in vitro experimental results, the catheter-mounted MFBP using the MFSS had a pump output of 3 L/min. against a differential pressure of 60 mmHg, and the pump characteristics of the MFBP were almost the same as those of Impella 5.0.

  2. Development of a Cloud System for Monitoring Blood Perfusion and Autonomic Nervous System Indices: The Mirror-Magical Project Invited

    Makoto Yoshizawa, Norihiro Sugita, Emi Yuda, Tomoyuki Yambe

    J106-C (3) 90-98 2022/11/18

    DOI: 10.14923/transelej.2022JCI0018  

    eISSN:1881-0217

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    In order to realize simple and easy health management at home or workplaces, our research group has been developing a cloud service system “The Mirror-Magical” that performs remote and contactless sensing of biological information without wearing any sensors, which was named “wear-less sensing.” The system can measure, accumulate, and analyze health-related information such as blood perfusion, autonomic nervous system indices, and blood pressure-related values. As well as on the cloud service system, this paper has reported on the “The Sphere-Magical”: a palm-based pulse wave measurement system that is never affected by body motion and lighting fluctuations, and the “The Eye-Magical”: a video pulse wave measurement system that can simultaneously analyze multiple faces, and discuss their effectiveness and limitations.

  3. Von Willebrand Factorの応答を考慮したECMOシステムの臨床的評価方法に関する検討

    中野 康太郎, 白石 泰之, 山田 昭博, 深谷 碧, 菅野 博童, 松浦 健, 早川 正樹, 松本 雅則, 堀内 久徳, 山家 智之

    人工臓器 51 (2) S-206 2022/10

    Publisher: (一社)日本人工臓器学会

    ISSN:0300-0818

    eISSN:1883-6097

  4. 磁気結合式完全埋込型拍動ポンプの経皮的駆動による血行動態評価

    高地 健, 山田 昭博, 白石 泰之, 永野 友香, 山家 智之

    ライフサポート 34 (3) 90-95 2022/09

    Publisher: (一社)ライフサポート学会

    ISSN:1341-9455

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    磁気結合による完全埋め込み可能な拍動ポンプ機構を開発し、成山羊の心臓と接続して皮下ポケットに留置し、左心補助効果について検討した。体外から経皮的に配置したサーボモータの設定拍動数を50~80bpmの駆動条件としてポンプ出力による血行動態変化を計測した。その結果、実拍動数と設定拍動数は線形関係があり、実拍動数は設定拍動数より約11%高かった。ポンプ出口圧から、60bpm駆動時の血圧は160/60mmHg、95bpm駆動時の血圧は120/45mmHgとなり、ポンプ始動前血圧(90/65mmHg)に対して圧補助効果を確認した。ポンプ一回拍出量とポンプ実拍動数から算出されたポンプ分時拍出量は、拍動数60bpm-90bpmの範囲で2.0-2.5L/min程度であった。

  5. In Vitro Modelling for Bulging Sinus Effects of an Expanded Polytetrafluoroethylene Valved Conduit Based on High-Speed 3D Leaflet Evaluation. International-journal

    Yasuyuki Shiraishi, Andrew J Narracott, Akihiro Yamada, Aoi Fukaya, Genta Sahara, Tomoyuki Yambe, Yuka Nagano, Masaaki Yamagishi

    Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual International Conference 2022 4001-4004 2022/07

    DOI: 10.1109/EMBC48229.2022.9871676  

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    The study aimed to develop a pulmonary circulatory system capable of high-speed 3D reconstruction of valve leaflets to elucidate the local hemodynamic characteristics in the valved conduits with bulging sinuses. Then a simultaneous measurement system for leaflet structure and pressure and flow characteristics was designed to obtain valve leaflet dynamic behaviour with different conduit structures. An image preprocessing method was established to obtain the three leaflets behaviour simultaneously for one sequence with two leaflets images from each pair of three high-speed cameras. Firstly, the multi-digital image correlation analyses were performed, and then the valve leaflet structure was measured under the static condition with fixed opening angles in the water-filled visualization chamber and the pulsatile flow tests simulating paediatric pulmonary flow conditions in the different types of conduit structures; with or without bulging sinuses. The results showed the maximum 3D reconstruction error to be around 0.06 mm. In the steady flow test, the evaluation of opening angles under the different flow rates conditions was achieved. In the pulsatile flow test, each leaflet's opening and closing behaviours were successfully reconstructed simultaneously at the high-frequency recording rate of 960fps. Therefore, the system developed in this study confirms the design evaluation method of an ePTFE valved conduit behaviour with leaflet structures interacting with local fluid dynamics in the vicinity of valves. Clinical Relevance- The system reveals the bulging sinus effects on ePTFE valve leaflet motion by the 3D reconstruction using multi-camera high-speed sequential imaging in vitro.

  6. 血液に対する剪断負荷評価のための試験システム小型化設計の試み

    中地 真太郎, 白石 泰之, 山田 昭博, 繁浦 瑠偉, 永野 友香, 伊藤 信一郎, 野田 祐資, 早川 正樹, 萱島 道徳, 松本 雅則, 堀内 久徳, 山家 智之

    人工臓器 51 (1) 38-38 2022/06

    Publisher: (一社)日本人工臓器学会

    ISSN:0300-0818

    eISSN:1883-6097

  7. 新規の磁気カップリング拍動ポンプ機構(New Magnet Coupling Pulsatile Pump Mechanism)

    Takachi Ken, Shiraishi Yasuyuki, Nagano Yuka, Yamada Akihiro, Yambe Tomoyuki

    ライフサポート 34 (2) 48-53 2022/06

    Publisher: (一社)ライフサポート学会

    ISSN:1341-9455

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    新たに植込型血液ポンプの脈流発生用に、電力に頼らずにエネルギー伝達を行う回転式の磁気カップリング成分を用いた拍動機序ポンプを開発した。ポンプは2種類の直径80mm半円型磁化ネオジム磁気プレートで構成し、ポリエチレン製の受動ダイアフラムとポンプで接続した。ポンプの本体に支持されているダイアフラムを誘引・反発するために回転磁界を適用した。ポンプの血行動態試験には機械循環システムを用い、60~100bpmの拍動条件下でエネルギー消費を調査した。その結果、この磁気カップリングポンプ機構では100mmHgの後負荷に対して4.6L/minの拍動流速度を生成でき、低ポンプ速度条件下でも効果的なポンプ力が示唆された。以上より、この経皮磁気カップリングによる間接拍動ポンプは全身血液循環を補助できると考えられた。

  8. Pre-implantation evaluation of a small-diameter, long vascular graft (Biotube®) for below-knee bypass surgery in goats. International-journal Peer-reviewed

    Yasuhide Nakayama, Ryosuke Iwai, Takeshi Terazawa, Tsutomu Tajikawa, Tadashi Umeno, Takayuki Kawashima, Yumiko Nakashima, Yasuyuki Shiraishi, Akihiro Yamada, Ryuji Higashita, Manami Miyazaki, Tomonori Oie, Satoki Kadota, Nozomi Yabuuchi, Fumie Abe, Marina Funayama-Iwai, Tomoyuki Yambe, Shinji Miyamoto

    Journal of biomedical materials research. Part B, Applied biomaterials 110 (11) 2387-2398 2022/05/13

    DOI: 10.1002/jbm.b.35084  

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    There are no small-diameter, long artificial vascular grafts for below-knee bypass surgery in chronic limb-threatening ischemia. We have developed tissue-engineered vascular grafts called "Biotubes®" using a completely autologous approach called in-body tissue architecture (iBTA). This study aimed at pre-implantation evaluation of Biotube and its in vivo preparation device, Biotube Maker, for use in below-knee bypass surgery. Forty nine makers were subcutaneously embedded into 17 goats for predetermined periods (1, 2, or 3 months). All makers produced Biotubes as designed without inflammation over all periods, with the exception of a few cases with minor defects (success rate: 94%). Small hole formation occurred in only a few cases. All Biotubes obtained had an inner diameter of 4 mm and a length of 51 to 52 cm with a wall thickness of 594 ± 97 μm. All Biotubes did not kink when completely bent under an internal pressure of 100 mmHg and did not leak without any deformation under a water pressure of 200 mmHg. Their burst strength was 2409 ± 473 mmHg, and suture retention strength was 1.75 ± 0.27 N, regardless of the embedding period, whereas tensile strength increased from 7.5 ± 1.3 N at 1 month to 9.7 ± 2.0 N at 3 months with the embedding period. The amount of water leakage from the needle holes prepared in the Biotube wall was approximately 1/7th of that in expanded polytetrafluoroethylene vascular grafts. The Biotubes could be easily connected to each other without cutting or anastomosis leaks. They could be stored for at least 1 year at room temperature. This study confirmed that even Biotubes formed 1 month after embedding of Biotube Makers had properties comparable to arteries.

  9. Acute Phase Pilot Evaluation of Small Diameter Long iBTA Induced Vascular Graft "Biotube" in a Goat Model. International-journal Peer-reviewed

    Ryuji Higashita, Yasuhide Nakayama, Yasuyuki Shiraishi, Ryosuke Iwai, Yusuke Inoue, Akihiro Yamada, Takeshi Terazawa, Tsutomu Tajikawa, Manami Miyazaki, Mamiko Ohara, Tadashi Umeno, Keitaro Okamoto, Tomonori Oie, Tomoyuki Yambe, Shinji Miyamoto

    EJVES vascular forum 54 27-35 2022

    DOI: 10.1016/j.ejvsvf.2022.01.004  

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    Objective: There is a need for small diameter vascular substitutes in the absence of available autologous material. A small diameter, long tissue engineered vascular graft was developed using a completely autologous approach called "in body tissue architecture technology (iBTA)". The aim of this pilot study was to evaluate "Biotubes", iBTA induced autologous collagenous tubes, for their potential use as small diameter vascular bypass conduits. Methods: Biotubes (internal diameter 4 mm, length 50 cm, wall thickness 0.85 mm) were prepared by subcutaneous embedding of plastic moulds (Biotube Maker) in three goats for approximately two months. Allogenic Biotubes (length 10 cm [n = 2], 15 cm [n = 2], 22 cm [n = 2]) were bypassed to both carotid arteries by end to side anastomosis with their ligation between the anastomoses in another three goats. Residual Biotubes were examined for their mechanical properties. After four weeks, the harvested Biotubes were evaluated histologically. Results: All Biotubes had sufficient pressure resistance, approximately 3000 mmHg. Although wall thickening occurred at two proximal anastomosis sites, all six grafts were patent without luminal thrombus formation, stenosis, or aneurysm deformation throughout the implantation period. Endothelial cells covered both anastomosis sites almost completely, with partial covering in the central portion of the grafts. Furthermore, α smooth muscle actin positive cells infiltrated the middle layer along almost the entire graft length. Conclusion: This preliminary study showed that small diameter, long, tissue engineered Biotubes could function properly as arterial bypass conduits in a large animal for one month without any abnormal change in vascular shape. Thus, small diameter, long Biotubes are potentially viable conduits, which are biocompatible and labour non-intensive, and therefore, suitable for clinical practice. Additionally, Biotubes can start the regeneration process in a short period of time.

  10. Remote, Non-Contact and Continuous Extraction of Multiple Peoples’ Autonomic Nervous System Indices from One Fish-Eye Camera

    Makoto Yoshizawa, Norihiro Sugita, Akira Tanaka, Noriyasu Homma, Emi Yuda, Tomoyuki Yambe

    Proceedings of the International Display Workshops 573-573 2021/12/02

    Publisher: International Display Workshops General Incorporated Association

    DOI: 10.36463/idw.2021.0573  

    ISSN:1883-2490

  11. Reflected wave intensity increases based on aortic diameter after endovascular aortic therapy in a goat model

    Tomohiro Takano, Masumi Iwai-Takano, Yusuke Tsuboko, Yasuyuki Shiraishi, Tomoyuki Yambe, Takashi Igarashi, Hitoshi Yokoyama

    Scientific Reports 11 (1) 2021/12

    Publisher: Springer Science and Business Media LLC

    DOI: 10.1038/s41598-020-80920-y  

    eISSN:2045-2322

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    <title>Abstract</title>Reflected wave increases after endovascular aortic repair (EVAR) in patients with aortic aneurysm. This affects the left ventricular (LV) diastolic function and leads to a poor prognosis. This study aimed to evaluate the relationship between increased reflected wave amplitude and aortic diameter after EVAR. EVAR was performed in seven healthy goats. We assessed wave intensity (WI), aortic diameter, and stiffness parameter β. Moreover, we evaluated the relationship between negative reflected wave (NW, reflected waves toward the heart from the periphery by WI) and other parameters after EVAR. Results showed an increase in stiffness parameter β (3.5 ± 0.3 vs 15.9 ± 4.7, <italic>p</italic> = 0.018) and a decrease in the change of aortic diameter (6.9 ± 0.7 vs 2.7 ± 0.4%, <italic>p</italic> = 0.018) after EVAR. The NW was significantly amplified after EVAR from baseline (−589.8 ± 143.4 to  − 1192.3 ± 303.7 mmHg-m/sec<sup>3</sup>, <italic>p</italic> = 0.043). The NW showed a significant correlation with maximum aortic diameter (R = 0.707, <italic>p</italic> = 0.038) and minimum aortic diameter (R = 0.724, <italic>p</italic> = 0.033). The reflected wave was enhanced after EVAR and was correlated to the aortic diameter at the stent-graft site. It is important to consider that patients with smaller aortic diameters in landing zone who undergo EVAR may develop LV dysfunction.

  12. Development of muscle connection components for implantable power generation system. International-journal

    Genta Sahara, Akihiro Yamada, Yusuke Inoue, Yasuyuki Shiraishi, Wataru Hijikata, Aoi Fukaya, Tomoyuki Yambe

    Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual International Conference 2021 7206-7210 2021/11

    DOI: 10.1109/EMBC46164.2021.9629561  

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    We have been developing an implantable power generation system that uses muscle contraction following electrical stimulation as a permanent power source for small implantable medical devices. However, if the muscle tissue is overloaded for power generation, the tissue may rupture or blood flow may be impaired. In this study, we developed a new muscle-connecting component that solves these problems. The new connection device has three rods attached to the muscle fibers, and the force exerted on the muscle fibers is converted from horizontal to vertical when the muscle contracts. We conducted simulations with a three-dimensional (3D) model, as well as pulse wave muscle measurements and in vivo tests using the actual muscle. The pulse wave in the connecting part and its downstream were optically measured from the muscle surface, and the blood flow was not obstructed. The 3D model simulations revealed that the distribution of stress was preferable compared with the case in which a rod was stuck vertically in the muscle. In the in vivo muscle tests, the metal rod and resin parts were attached to the muscle, and a load of up to approximately 9 N was applied to the connecting part. Consequently, the connecting part was stable and integrated with the muscle, and there was no damage in the muscle. Although no long-term or histological evaluations were conducted, the device may be useful because of the intramuscular power generation owing to the minimal load applied on the part connected with the muscle.

  13. Design of an Artificial Tongue Driven by Shape Memory Alloy Fibers

    Yasuyuki Shiraishi, Akihiro Yamada, Genta Sahara, Tomoyuki Yambe, Kengo Kato, Jun Ohta, Yukio Katori, Dai Homma

    2021 43rd Annual International Conference of the IEEE Engineering in Medicine & Biology Society (EMBC) 2021/11/01

    Publisher: IEEE

    DOI: 10.1109/embc46164.2021.9630283  

  14. iBTA-Induced Biotube<sup>®</sup> Blood Vessels: 2020 Update Peer-reviewed

    Yasuhide Nakayama, Ryuji Higashita, Yasuyuki Shiraishi, Tadashi Umeno, Tsutomu Tajikawa, Akihiro Yamada, Kazuki Mori, Manami Miyazaki, Mamiko Ohara, Ryosuke Iwai, Takeshi Terazawa, Tomonori Oie, Tomoyuki Yambe, Shinji Miyamoto

    Kidney and Dialysis 2021/06

    DOI: 10.3390/kidneydial1010002  

  15. Hemolysis and von Willebrand factor degradation in mechanical shuttle shear flow tester.

    Yasuyuki Shiraishi, Yuma Tachizaki, Yusuke Inoue, Masaki Hayakawa, Akihiro Yamada, Michinori Kayashima, Masanori Matsumoto, Hisanori Horiuchi, Tomoyuki Yambe

    Journal of artificial organs : the official journal of the Japanese Society for Artificial Organs 24 (2) 111-119 2021/06

    DOI: 10.1007/s10047-020-01219-3  

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    Chronic blood trauma caused by the shear stresses generated by mechanical circulatory support (MCS) systems is one of the major concerns to be considered during the development of ventricular assist devices. Large multimers with high-molecular-weight von Willebrand factor (VWF) are extended by the fluid forces in a shear flow and are cleaved by ADAMTS13. Since the mechanical revolving motions in artificial MCSs induce cleavage in large VWF multimers, nonsurgical bleeding associated with the MCS is likely to occur after mechanical hemodynamic support. In this study, the shear stress (~ 600 Pa) and exposure time related to hemolysis and VWF degradation were investigated using a newly designed mechanical shuttle shear flow tester. The device consisted of a pair of cylinders facing the test section of a small-sized pipe; both the cylinders were connected to composite mechanical heads with a sliding-sleeve structure for axial separation during the withdrawing motion. The influence of exposure time, in terms of the number of stress cycles, on hemolysis and VWF degradation was confirmed using fresh goat blood, and the differences in the rates of dissipation of the multimers were established. The plasma-free hemoglobin levels showed a logarithmic increase corresponding to the number of cycles, and the dissipation of large VWF multimers occurred within a few seconds under high shear stress flow conditions.

  16. Development and accuracy evaluation of a degree of occlusion visualization system for roller pumps used in cardiopulmonary bypass.

    Aoi Fukaya, Yasuyuki Shiraishi, Yusuke Inoue, Akihiko Yamada, Genta Sahara, Takemi Kudo, Yasuhiro Aizawa, Tomoyuki Yambe

    Journal of artificial organs : the official journal of the Japanese Society for Artificial Organs 24 (1) 27-35 2021/03

    DOI: 10.1007/s10047-020-01211-x  

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    In roller pumps used for cardiopulmonary bypass (CPB), the degree of blockage within the tube resulting from compression of the tube by the rollers, or the degree of occlusion, is closely related to hemolysis, with both tight occlusive and non-occlusive degrees promoting hemolysis. There are as yet no international standards regarding methods of adjusting occlusiveness, and the amount of mechanical stress exerted upon blood remains unknown. To prevent hemolysis during CPB using roller pumps, there is a need to clarify and quantitatively assess the mechanical stress of the occlusiveness of the roller pump. In this study, we have developed a degree of occlusion quantification system which constructs the flow channel shape within an occluded tube from red optical density images, and we have verified the validity of this system. Utilizing a linear actuator, an acrylic roller and raceway, a solution colored with simulated blood powder, and a 3/8-inch vinyl chloride tube, this system uses a camera to capture red optical density images within an occluded tube and constructs the tube flow channel shape using a formula manipulation system. To verify the accuracy of this system, we compared the thickness of a cross-section of the flow channel constructed with the degree of occlusion quantification system with the thickness of a cross-section of silicone cured under the same occlusion conditions. Our experiments indicated that for areas with a small tube gap, this system can construct highly accurate three-dimensional shapes and obtain quantitative indicators assessing the degree of occlusion.

  17. Reflected wave intensity increases based on aortic diameter after endovascular aortic therapy in a goat model. International-journal

    Tomohiro Takano, Masumi Iwai-Takano, Yusuke Tsuboko, Yasuyuki Shiraishi, Tomoyuki Yambe, Takashi Igarashi, Hitoshi Yokoyama

    Scientific reports 11 (1) 3830-3830 2021/02/15

    DOI: 10.1038/s41598-020-80920-y  

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    Reflected wave increases after endovascular aortic repair (EVAR) in patients with aortic aneurysm. This affects the left ventricular (LV) diastolic function and leads to a poor prognosis. This study aimed to evaluate the relationship between increased reflected wave amplitude and aortic diameter after EVAR. EVAR was performed in seven healthy goats. We assessed wave intensity (WI), aortic diameter, and stiffness parameter β. Moreover, we evaluated the relationship between negative reflected wave (NW, reflected waves toward the heart from the periphery by WI) and other parameters after EVAR. Results showed an increase in stiffness parameter β (3.5 ± 0.3 vs 15.9 ± 4.7, p = 0.018) and a decrease in the change of aortic diameter (6.9 ± 0.7 vs 2.7 ± 0.4%, p = 0.018) after EVAR. The NW was significantly amplified after EVAR from baseline (-589.8 ± 143.4 to  - 1192.3 ± 303.7 mmHg-m/sec3, p = 0.043). The NW showed a significant correlation with maximum aortic diameter (R = 0.707, p = 0.038) and minimum aortic diameter (R = 0.724, p = 0.033). The reflected wave was enhanced after EVAR and was correlated to the aortic diameter at the stent-graft site. It is important to consider that patients with smaller aortic diameters in landing zone who undergo EVAR may develop LV dysfunction.

  18. Effect of a Television Commercial on the Autonomic Nervous System

    Tomoyuki Yambe, Yasuyuki Shiraishi, Yusuke Inoue, Akihiro Yamada, Makoto Yoshizawa

    IFMBE Proceedings 77-82 2021

    Publisher: Springer International Publishing

    DOI: 10.1007/978-3-030-66169-4_11  

    ISSN:1680-0737

    eISSN:1433-9277

  19. Preliminary Study of an Objective Evaluation Method for Pulse Diagnosis using Radial Artery Pulse Measurement Device

    Akihiro Yamada, Yusuke Inoue, Yasuyuki Shiraishi, Takashi Seki, Tomoyuki Yambe

    Advanced Biomedical Engineering 10 113-122 2021

    Publisher: Japanese Society for Medical and Biological Engineering

    DOI: 10.14326/abe.10.113  

    eISSN:2187-5219

  20. 経皮的磁気伝達駆動拍動ポンプの駆出特性改善型の開発

    高地 健, 山田 昭博, 白石 泰之, 山家 智之

    人工臓器 49 (2) S-174 2020/10

    Publisher: (一社)日本人工臓器学会

    ISSN:0300-0818

    eISSN:1883-6097

  21. 機械循環の高せん断によるフォンウィルブランド因子マルチマー切断に関する研究

    井上 雄介, 早川 政樹, 山田 昭博, 佐原 玄太, 白石 泰之, 佐藤 康史, 武輪 能明, 堀内 久徳, 松本 雅則, 山家 智之

    人工臓器 49 (2) S-138 2020/10

    Publisher: (一社)日本人工臓器学会

    ISSN:0300-0818

    eISSN:1883-6097

  22. In vitro performance of trans-valve left ventricular assist device installed at aortic valve position. International-journal

    Eiji Okamoto, Tetsuya Yano, Yusuke Inoue, Yasuyuki Shiraishi, Tomoyuki Yambe, Yoshinori Mitamura

    Artificial organs 44 (10) 1067-1072 2020/10

    DOI: 10.1111/aor.13687  

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    In this study, we developed a trans-valve left ventricular assist device (LVAD) that unites a rear-impeller axial-flow blood pump (AFBP) and a polymer membrane valve placed at the aortic valve position. The diameter and length of the rear impeller AFBP was 12 and 63 mm, respectively. The polymer membrane valve was similar to the jelly-fish valve consisting of a valve leaflet made of silicone rubber (thickness 0.5 mm), valve ring (diameter: 25 mm), and valve spokes. The trans-valve LVAD was examined in a mock circulation. An implantable pulsatile flow (PF) VAD was connected to an atrial reservoir to simulate the left ventricle (LV), and the Hall valve was worn in the inflow port, and the trans-valve LVAD was placed in the outflow port as an outflow valve. When the motor rotational speed increased to 26 400 rpm, the mean aortic flow increased from 4.2 to 5.3 L/min, mean aortic pressure increased from 83.4 to 100 mm Hg, and mean motor current of the implantable PF VAD decreased from 1.18 to 0.94 A (unloading effect on LV -21%). The energy equivalent pressure increased from 85.2 to 102 mm Hg, and surplus hemodynamic energy (SHE) decreased by -15.4% from the baseline. In conclusion, the trans-valve LVAD has an advantage of preserving pulsatility without any complicated mechanism and is a novel and promising LV support device.

  23. ステントグラフト治療後の反射波増加は大動脈径に依存する ヤギ実験モデルにおけるwave intensityの評価

    高野 智弘, 高野 真澄, 坪子 侑佑, 白石 泰之, 山家 智之, 横山 斉

    脈管学 60 (Suppl.) S119-S119 2020/10

    Publisher: (一社)日本脈管学会

    ISSN:0387-1126

    eISSN:1880-8840

  24. ステントグラフト治療後の反射波増加は大動脈径に依存する ヤギ実験モデルにおけるwave intensityの評価

    高野 智弘, 高野 真澄, 坪子 侑佑, 白石 泰之, 山家 智之, 横山 斉

    脈管学 60 (Suppl.) S119-S119 2020/10

    Publisher: (一社)日本脈管学会

    ISSN:0387-1126

    eISSN:1880-8840

  25. Pulse rate variability: a new biomarker, not a surrogate for heart rate variability. International-journal

    Emi Yuda, Muneichi Shibata, Yuki Ogata, Norihiro Ueda, Tomoyuki Yambe, Makoto Yoshizawa, Junichiro Hayano

    Journal of physiological anthropology 39 (1) 21-21 2020/08/18

    DOI: 10.1186/s40101-020-00233-x  

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    With the popularization of pulse wave signals by the spread of wearable watch devices incorporating photoplethysmography (PPG) sensors, many studies are reporting the accuracy of pulse rate variability (PRV) as a surrogate of heart rate variability (HRV). However, the authors are concerned about their research paradigm based on the assumption that PRV is a biomarker that reflects the same biological properties as HRV. Because PPG pulse wave and ECG R wave both reflect the periodic beating of the heart, pulse rate and heart rate should be equal, but it does not guarantee that the respective variabilities are also the same. The process from ECG R wave to PPG pulse wave involves several transformation steps of physical properties, such as those of electromechanical coupling and conversions from force to volume, volume to pressure, pressure impulse to wave, pressure wave to volume, and volume to light intensity. In fact, there is concreate evidence that shows discrepancy between PRV and HRV, such as that demonstrating the presence of PRV in the absence of HRV, differences in PRV with measurement sites, and differing effects of body posture and exercise between them. Our observations in adult patients with an implanted cardiac pacemaker also indicate that fluctuations in R-R intervals, pulse transit time, and pulse intervals are modulated differently by autonomic functions, respiration, and other factors. The authors suggest that it is more appropriate to recognize PRV as a different biomarker than HRV. Although HRV is a major determinant of PRV, PRV is caused by many other sources of variability, which could contain useful biomedical information that is neither error nor noise.

  26. Modeling Approach for An Aortic Dissection with Endovascular Stenting. International-journal

    Yasuyuki Shiraishi, Tomoyuki Yambe, Andrew J Narracott, Akihiro Yamada, Ryosuke Morita, Yi Qian, Kazuhiko Hanzawa

    Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual International Conference 2020 5008-5011 2020/07

    DOI: 10.1109/EMBC44109.2020.9176423  

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    Repair of dissected aorta requires remodeling the structure of the media. Modeling approaches specific to endovascular stenting for aortic dissection have been reported. We created a goat model of descending thoracic aortic dissection and reproduced its morphological characteristics in a mock circulatory system. The purpose of this study was to examine a newly developed aortic stent which was capable of installing to the aortic dissected lesion for biomedical hemodynamics point of view. In this study, we examined the changes in hemodynamics of dissected lesions and the amelioration by endovascular stent intervention. Firstly, we performed animal experiments with the dissected aorta and examined the effects of stenting on volumetric changes in the false lumen. Secondly, we made several types of 3-D stereolithographic dissected aortic models with silicone rubber membrane between the false and the true lumens. Then, the hemodynamic characteristics in each model were evaluated in the pulsatile flow conditions in a mock circulatory system. These modelling approaches enabled the quantitative examination of post-therapeutic effects of stenting followed by elucidating of hemodynamic changes in the vicinity of stents, which may follow the management of clinical amelioration of interventional treatment with aortic stenting.Clinical Relevance- This study represents a modelling approach of the dissected aorta for endovascular intervention using stenting followed by the examination of false lumen volumetric changes resulting in the deterioration of pressure increase in diseased lesions.

  27. 微細管路系による流体剪断負荷とvon Willebrand factor損傷に関する特性評価の基礎検討

    舘崎 祐馬, 白石 泰之, 井上 雄介, 山田 昭博, 岩元 直樹, 盛田 良介, Ibadurrahman Ahmad Faiz, 橋本 真登香, 早川 正樹, 萱島 道徳, 松本 雅則, 堀内 久徳, 山家 智之

    人工臓器 49 (1) 37-37 2020/06

    Publisher: (一社)日本人工臓器学会

    ISSN:0300-0818

    eISSN:1883-6097

  28. 微細管路系による流体剪断負荷とvon Willebrand factor損傷に関する特性評価の基礎検討

    舘崎 祐馬, 白石 泰之, 井上 雄介, 山田 昭博, 岩元 直樹, 盛田 良介, Ibadurrahman Ahmad Faiz, 橋本 真登香, 早川 正樹, 萱島 道徳, 松本 雅則, 堀内 久徳, 山家 智之

    人工臓器 49 (1) 37-37 2020/06

    Publisher: (一社)日本人工臓器学会

    ISSN:0300-0818

    eISSN:1883-6097

  29. Evaluation of a new quantitative CPB occlusion measurement system in a mechanical squeezed model

    Fukaya Aoi, Shiraishi Yasuyuki, Inoue Yusuke, Yamada Akihiro, Sahara Genta, Kudo Takemi, Aizawa Yasuhiro, Yambe Tomoyuki

    Transactions of Japanese Society for Medical and Biological Engineering 58 266-266 2020

    Publisher: Japanese Society for Medical and Biological Engineering

    DOI: 10.11239/jsmbe.Annual58.266  

    ISSN:1347-443X

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    <p>Hemolysis is one of the major blood trauma in extracorporeal circulation. The occlusion is a parameter to eliminate deteriorative blood trauma as well as to improve assisted circulation efficiency during cardiopulmonary bypass (CPB). A new occlusion simulation model was developed to evaluate the occlusion by the thickness of the flow in the tubing compressed with the CPB roller and raceway. The red-coloured densimetry images were used to calculate the thickness of occluded flow channel. In this study, we examined two types of occlusion measurements and compared the thickness of the flow in the model: a) the coloured densimetry, and b) a 3D measurement of the casted silicone. As a result, the cross-section depths showed a linear relation with the thickness lower than 120 microns. Therefore, the colour densimetry occlusion measurement model might be useful for the quantitative evaluation for CPB occlusion by the 3D reconstruction of the squeezed flow layers.</p>

  30. Modeling Approach for An Aortic Dissection with Endovascular Stenting

    Yasuyuki Shiraishi, Tomoyuki Yambe, Andrew J. Narracott, Akihiro Yamada, Ryosuke Morita, Yi Qian, Kazuhiko Hanzawa

    42ND ANNUAL INTERNATIONAL CONFERENCES OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY: ENABLING INNOVATIVE TECHNOLOGIES FOR GLOBAL HEALTHCARE EMBC'20 5008-5011 2020

    Publisher: IEEE

    ISSN:1557-170X

    eISSN:1558-4615

    More details Close

    Repair of dissected aorta requires remodeling the structure of the media. Modeling approaches specific to endovascular stenting for aortic dissection have been reported. We created a goat model of descending thoracic aortic dissection and reproduced its morphological characteristics in a mock circulatory system. The purpose of this study was to examine a newly developed aortic stent which was capable of installing to the aortic dissected lesion for biomedical hemodynamics point of view. In this study, we examined the changes in hemodynamics of dissected lesions and the amelioration by endovascular stent intervention. Firstly, we performed animal experiments with the dissected aorta and examined the effects of stenting on volumetric changes in the false lumen. Secondly, we made several types of 3-D stereolithographic dissected aortic models with silicone rubber membrane between the false and the true lumens. Then, the hemodynamic characteristics in each model were evaluated in the pulsatile flow conditions in a mock circulatory system. These modelling approaches enabled the quantitative examination of post-therapeutic effects of stenting followed by elucidating of hemodynamic changes in the vicinity of stents, which may follow the management of clinical amelioration of interventional treatment with aortic stenting.

  31. Modeling Approach for An Aortic Dissection with Endovascular Stenting.

    Yasuyuki Shiraishi, Tomoyuki Yambe, Andrew J. Narracott, Akihiro Yamada, Ryosuke Morita, Yi Qian, Kazuhiko Hanzawa

    5008-5011 2020

    DOI: 10.1109/EMBC44109.2020.9176423  

  32. Optimum Sterilization Methods of Biocompatible Hybrid Material for Artificial Organs Peer-reviewed

    Inoue Yusuke, Shiraishi Yasuyuki, Yamada Akihiro, Yambe Tomoyuki, Abe Yusuke, Tashiro Ayaka, Kawase Yukino, Isoyama Takashi, Saito Itsuro, Ono Toshiya, Hara Shintaro, Ishii Kohei, Yurimoto Terumi

    Advanced Biomedical Engineering 9 (0) 83-92 2020

    Publisher: Japanese Society for Medical and Biological Engineering

    DOI: 10.14326/abe.9.83  

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    <p>We previously reported the development of a new hybrid medical material comprising bio-based materials with high biocompatibility and artificial materials with characteristics of excellent strength and processability. This material shows sufficient biocompatibility and excellent stability <i>in vivo</i>. Moreover, when applied to the surface of an implantable sensor, the biological reaction on the sensor function surface can be well controlled. For commercialization and widespread use of hybrid materials with such superior properties, sterilization and storage are critical considerations, given that hybrid materials must be processed outside the body prior to application as medical materials <i>in vivo</i>, thus posing a risk of contamination despite best efforts. Therefore, the aim of the present study was to establish an optimal sterilization method that will not impair the biocompatibility of the hybrid material. Toward this end, we tested six sterilization methods for the hybrid material: autoclave (121℃, 20 min), dry heat (160℃, 120 min), ethylene oxide gas (37℃, 120 min), hydrogen peroxide plasma (45℃, 45 min), and gamma ray (25 kGy) with and without lyophilization. After sterilization, the material was cultured with vascular endothelial cells to evaluate the engraftment rate, and was observed with light and scanning electron microscopy to determine shape and structure changes. The results demonstrated that gamma sterilization without lyophilization was the best sterilization method for this material, which preserved the collagen network and showed no change in number of adhered vascular endothelial cells compared to the pre-sterilized material. These findings are useful to promote the commercialization of this hybrid material with combined advantages of synthetic and bio-based materials for widespread clinical application in the engineering of artificial organs.</p>

  33. Development of smart-textile for lifetime vital sensing Peer-reviewed

    Inoue Yusuke, Ahmad Faiz Ibadurrahma, Hashimoto Madoka, Shiraishi Yasuyuki, Yambe Tomoyuki, Yokota Tomoyuki, Ishii Kohei, Yamada Akihiro, Iwamoto Naoki, Tachizaki Yuma, Morita Ryosuke, Sahara Genta, Fukaya Aoi

    Transactions of Japanese Society for Medical and Biological Engineering 58 (0) 409-409 2020

    Publisher: Japanese Society for Medical and Biological Engineering

    DOI: 10.11239/jsmbe.Annual58.409  

    ISSN:1347-443X

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    <p>Medical biometric information is required to be measured in a resting state or under constrained constraints. However, adverse effects on the measurement results caused by the environment at the time of measurement are implicitly accepted. A smart device that integrates these sensors with little wearing feeling into one device and can obtain biological information (pulse, electrocardiogram, body temperature distribution, body movement) that could not be measured at the same time from one clothes. Smart Textile can not only obtain measurement results without disturbance that releases the limitations of existing wearable devices, but also acquire biological information in all situations such as sleep, eating, exercise, etc.The ultimate goal is to acquire the big data of the whole living time by using the smart textile created by this research, and to develop new medical equipment and health care devices based on this information.</p>

  34. 微細管路系による流体剪断負荷とvon Willebrand factor損傷に関する特性評価の基礎検討

    舘崎 祐馬, 白石 泰之, 井上 雄介, 山田 昭博, 岩元 直樹, 盛田 良介, Ibadurrahman Ahmad Faiz, 橋本 真登香, 堀内 久徳, 早川 正樹, 松本 雅則, 萱島 道徳, 山家 智之

    人工臓器 48 (2) S-241 2019/10

    Publisher: (一社)日本人工臓器学会

    ISSN:0300-0818

    eISSN:1883-6097

  35. Development of a blood shear stress tester for modelling of acquired von Willebrand syndrome

    Yuma TACHIZAKI, Keito FUKUZAWA, Yasuyuki SHIRAISHI, Yusuke INOUE, Akihiro YAMADA, Masaki HAYAKAWA, Michinori KAYASHIMA, Masanori MATSUMOTO, Hisanori HORIUCHI, Tomoyuki YAMBE

    The Proceedings of the Bioengineering Conference Annual Meeting of BED/JSME 2019.32 1E24-1E24 2019

    Publisher: Japan Society of Mechanical Engineers

    DOI: 10.1299/jsmebio.2019.32.1e24  

    eISSN:2424-2829

  36. 人工心肺用ローラポンプ適正圧閉度の定量評価システムの構築

    深谷 碧, 白石 泰之, 相澤 康弘, 山家 智之

    生体医工学 57 S221_1-S221_1 2019

    Publisher: 公益社団法人 日本生体医工学会

    DOI: 10.11239/jsmbe.Annual57.S221_1  

    ISSN:1347-443X

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    <p>心臓手術に用いられる人工心肺装置のローラポンプは圧閉度と溶血が関係し、過度圧閉や不完全圧閉はともに溶血を引き起こす。圧閉度調整方法は日本工業規格JIS T 1603に規定されている。一方これらの指標に関しては、近年の血液適合性に関する医工学的定量評価に基づく安全性評価が重要である。臨床現場では、ローラポンプ使用前の圧閉度調整の定量性および確実性を向上させ、人工心肺装置使用時の溶血による急性腎障害を低減させることが求められており、本研究では、これらの臨床的課題に関して医工学的評価に基づく定量的な科学的根拠を示すことを目標としている。そこで、我々はマイクロフォーカスX線CT装置を用いて圧閉されるチューブの断面積を計測し、計測した断面積の形態をパラメータとして、流量特性および血液損傷を検証するための新たな圧閉度の評価システムを開発した。ローラポンプに用いられるチューブは内径や肉厚、コンプライアンスが異なる。これらローラポンプに用いられるチューブの基礎特性が及ぼす影響と構築したシステムによる圧閉度との関係について医工学的観点からのアプローチを提示する。</p>

  37. 解離性大動脈瘤血行動態モデリングの試み

    盛田 良介, 山家 智之, 白石 泰之, 榛沢 和彦, Qian Yi, Narracott Andrew, 井上 雄介, 山田 昭博, 岩元 直樹, 舘崎 祐馬

    生体医工学 57 (0) S220_2-S220_2 2019

    Publisher: 公益社団法人 日本生体医工学会

    DOI: 10.11239/jsmbe.Annual57.S220_2  

    ISSN:1347-443X

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    <p>【背景】解離性大動脈瘤では解離偽腔内に流入する血流がもたらす乱流による複雑な圧流量特性が観察される。治療効果と安全性を評価する上では血管内治療用の解離性大動脈瘤内の血圧血流速の医工学的モデリングが重要となっている。【目的】これまで解離性大動脈瘤の動物実験モデルを作成し血行動態の再現を行ってきた。本研究では動物実験から得られた超音波画像を基に解離性大動脈瘤血行動態のモデリングを目的としてそれらの解析手法に関して評価を進めた。【方法】〔動物解離モデル〕健常成山羊を麻酔下にて開胸し、下行大動脈の中枢側外膜を切開後、中膜を外科的に剥離し、血管開口部を切開し大動脈解離を作成した。〔モデル化手法・解析〕下行大動脈の超音波短軸像を血管長軸に沿って1mm毎の断層像とし、データの数値的再構成により形状モデルを構築した。作成したモデルを用いて模擬循環回路による流れ可視化と数値流体解析を行った。【まとめ】動物モデルでは臨床に近い形態と血流を再現できる一方、血管内治療の血行力学的評価については血流形態の差や計測誤差の課題がある。解離性大動脈瘤治療ではさまざまな医工学モデリング方法論で安全性評価が可能である。</p>

  38. 接触型ウェアラブルセンサのノイズと装着感の低減を目的とした基礎研究 Peer-reviewed

    井上 雄介, 佐原 玄太, 深谷 碧, 白石 泰之, 山家 智之, 横田 知之, 石井 耕平, 山田 昭博, 軽部 雅人, 源田 達也, 岩元 直樹, 舘崎 祐馬, 盛田 良介

    生体医工学 57 (0) S36_2-S36_2 2019

    Publisher: 公益社団法人 日本生体医工学会

    DOI: 10.11239/jsmbe.Annual57.S36_2  

    ISSN:1347-443X

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    <p>医療生体情報は安静状態か拘束された制約下での計測が必須であり、計測時の環境が与える計測結果への影響は必要悪として無視されている。我々は装着感のない接触型センサを開発しており、計測による制約から解放することで外乱のない計測結果を得られるだけでなく、これまで安定計測できなかった睡眠・食事・運動時などあらゆる場面で生体情報を取得することを目的するものである。開発したシステムと既存のセンサとで生体に与えるストレス影響を循環生理学的に比較してその装着感を定量的に評価する。本研究により全生活時間のビッグデータを取得し、この情報を元に新たな医療機器・ヘルスケアデバイスを開発することが最終目標である。本発表では、3つの拠点で実施した、筋電・心電・温度・心拍を対象としたセンサの開発と装着感の評価に関する報告を行う。</p>

  39. Development of Evaluation System for Von Willebrand Factor Degradation by Shear Stress of Mechanical Circulation Peer-reviewed

    Yusuke Inoue, Masaki Hayakawa, Masanori Matsumoto, Hisanori Horiuchi, Yasuyuki Shiraishi, Akihiro Yamada, Masato Karube, Tatsuya Genda, Tomoyuki Yambe

    40th International Engineering in Medicine and Biology Conference 40 (1) 31-31 2018/07

  40. Simulation of various circulatory abnormalities with hybrid mock system and evaluation of control method

    Oizumi Kentaro, Tnaka Akira, Yoshizawa Makoto, Shiraishi Yasuyuki, Yambe Tomoyuki, Motomura Tadashi

    Transactions of Japanese Society for Medical and Biological Engineering 55 (4) 269-269 2017

    Publisher: Japanese Society for Medical and Biological Engineering

    DOI: 10.11239/jsmbe.55Annual.269  

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    <p>A synchronized control of left ventricular assist devices has some advantages in comparison with constant rotational speed control. However, because a risk of occurrence of abnormal situation such as suction and regurgitation increase, the controller should adapt such abnormal situations. The aim of this study is to simulate the abnormal condition using hybrid-mock circulatory system combining computer simulator and mock circulatory system.Suction, regurgitation and deterioration of heart function were simulated in hybrid-mock circulatory system and the each behavior were compared with the results of animal experiments.As a result, it was confirmed that the abnormal situation simulated using the hybrid-mock circulatory system and each behavior was similar as the result of the animal experiment. Therefore, it is possible to investigate and evaluate the control algorithm using actual pump and controller.</p>

  41. Investigation of an effect of cannula size on assist flow and compensation by pump control

    Jimbo Yuki, Tanaka Akira, Yoshizawa Makoto, Shiraishi Yasuyuki, Yambe Tomoyuki, Motomura Tadashi

    Transactions of Japanese Society for Medical and Biological Engineering 55 (4) 270-270 2017

    Publisher: Japanese Society for Medical and Biological Engineering

    DOI: 10.11239/jsmbe.55Annual.270  

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    <p>An implantable type ventricular assist device becomes mainstream, but an extracorporeal type pump has advantage in case of short term assistance. However, in the case of extracorporeal type device, it is expected that the assist flow is affected by cannula diameter and length. In this study, the influence of diameter and length of the cannula on assist flow was investigated and compensation method by pump control was proposed.The HQ curves combining cannula with pump was obtained. The model expressing HQ curve was identified from measured data and the slope of HQ curve at any drive point was evaluated. In result, although the same assist flow was actualized in small diameter by high pump speed, the slope of HQ curve around driving point became steep. Besides, the result indicated that the steepness was compensated by dynamic rotational speed control such as co-pulse mode control.</p>

  42. 虚血性心筋症の外科治療成績

    川本 俊輔, 高橋, 誠, 小田, 克彦, 熊谷, 紀一郎, 秋山, 正年, 安達, 理, 増田, 信也, 藤原, 英記, 吉岡, 一朗, 河津, 聡, 片平, 晋太郎, 神田, 桂輔, 鈴木, 智之, 細山, 勝寛, 正木, 直樹, 高原, 真吾, 坂爪, 公, 渡邊, 晃佑, 齋木 佳克

    日本冠疾患学会雑誌 22 (2) 87-92 2016

    Publisher: None

    DOI: 10.7793/jcoron.22.15-00026  

    ISSN:1341-7703

    eISSN:2187-1949

  43. 再手術を考慮した補助人工心臓装着術

    秋山 正年, 河津, 聡 片平, 晋太郎, 高原, 真吾, 坂爪, 公, 細山, 勝寛, 正木, 直樹, 神田, 桂輔, 鈴木, 智之, 藤原, 英記, 安達, 理, 熊谷, 紀一郎, 川本, 俊輔, 齋木 佳克

    日本心臓血管外科学会雑誌 44 (Supplement) 331-331 2015

    Publisher: None

    ISSN:0285-1474

    eISSN:1883-4108

  44. 先天性大動脈弁二尖弁術後の心臓大血管イベントを包括した長期遠隔成績

    正木 直樹, 坂爪, 公, 高原, 真吾, 細山, 勝寛, 神田, 桂輔, 鈴木, 智之, 片平, 晋太郎, 河津, 聡, 齋藤, 武志, 藤原, 英記, 安達, 理, 秋山, 正年, 熊谷, 紀一郎, 川本, 俊輔, 齋木 佳克

    日本心臓血管外科学会雑誌 44 (Supplement) 301-301 2015

    Publisher: None

    ISSN:0285-1474

    eISSN:1883-4108

  45. Heartbeat detection using modeling error and beat synchronized control of rotary left ventricular assist device

    HATAYA GENTA, TANAKA AKIRA, YOSHIZAWA MAKOTO, SHIRAISHI YASUYUKI, MIURA HIDEKAZU, YAMBE TOMOYUKI

    Transactions of Japanese Society for Medical and Biological Engineering 53 S196_03-S196_03 2015

    Publisher: Japanese Society for Medical and Biological Engineering

    DOI: 10.11239/jsmbe.53.S196_03  

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    It is reported that a synchronized control of rotary left ventricular assist devices has some advantages in comparison with constant rotational speed control. The most common way to synchronize to heart beat is to use ECG signal because R-wave represents the beginning of systole and is easily detected. However, it is difficult to detect the onset of diastole. The aim of this study is to develop the algorithm to synchronize to heart cycle without external sensors such as ECG.In proposed method, a heartbeat was regarded as disturbance to pump rotational speed. Thus the disturbance was estimated as the difference between measured and estimated rotational speed. An ARX model which input was the reference of pump speed and current consumption was adopted to estimate the instantaneous rotational speed. The proposed method was tested in both a mock circulatory system and animal experiments. The results indicated that the system can output the heart cycle signal and detect not only the onset of systole but that of diastole. Furthermore, co-pulse and counter-pulse mode control can be demonstrated by using the detected timing. However there was detection delay at start of systole.

  46. Detection of aortic valve opening during rotary blood pump support using support vector machine

    TAKANOHASHI SHUHEI, TANAKA AKIRA, YOSHIZAWA MAKOTO, SHIRAISHI YASUYUKI, MIURA HIDEKAZU, YAMBE TOMOYUKI

    Transactions of Japanese Society for Medical and Biological Engineering 53 S196_02-S196_02 2015

    Publisher: Japanese Society for Medical and Biological Engineering

    DOI: 10.11239/jsmbe.53.S196_02  

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    The left ventricular assist device(LVAD) has not only a role as the circulatory support but also as left ventricular unloading.Although high assist rate is effective for ventricular unloading,it may cause aortic flow stagnation,which may cause thrombosis or fusion of the aortic valve.Therefore,it is important to adjust a pump output corresponding to a condition of aortic valve opening.In this study,a method for detecting whether aortic valve is open has been proposed and evaluated.Support Vector Machine(SVM) of which feature variables were a rotational speed and current consumption was used for state classification.In addition,the empirical verification algorithm was applied to SVM output in order to improve sensitivity and specificity.The training and evaluation data were obtained from animal experiments using adult goats.The SVM gave a good performance when second derivative of the variables were used as features.The result indicated that the proposed algorithm have practical performance for aortic valve state detection.The information of an aortic valve state may contribute to development for automatic controller for LVAD.In future study,it is necessarily to investigate an individual difference of the parameters.

  47. Histological observation of titanium mesh electrode for transcutaneous information transmission using human body as conductive medium

    OKAMOTO EIJI, SHIDA AKANE, MIURA HIDEKAZU, SHIRAISHI YASUYUKI, YAMBE TOMOYUKI, MITAMURA YOSHINORI

    Transactions of Japanese Society for Medical and Biological Engineering 53 S199_03-S199_03 2015

    Publisher: Japanese Society for Medical and Biological Engineering

    DOI: 10.11239/jsmbe.53.S199_03  

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    We have developed a transcutaneous communication system using intrabody communication, and we proposed a titanium mesh electrode to obtain mechanically and electrically stable contact with tissue by inducing surrounding tissue. In this study, we studied histocompatibility of the titanium mesh with the inner wall of the thoracic cavity using a goat. A transmission current of 6 mA with a frequency of 4 MHz is within maximum allowable current applying a human body according to the ICNIRP guideline. However, the data transmission current had an effect on the tissue inside the titanium mesh, and more numbers of inflammatory cells were induced into the titanium mesh. The titanium mesh electrode on the internal communication unit was filled with more numbers of inflammatory cells rather than the titanium mesh electrode implanted alone. Stress inside the titanium mesh due to movement of the communication unit would evoke immune reaction, and it induced inflammatory cells into the titanium mesh. While physical stimuli such as stress and current would evoke week inflammatory immune response, the titanium mesh is suitable material for an electrode that can be implanted inside the body.

  48. Effects of blood volume on non-invasive assessment of peripheral perfusion with ventricular assist devices using a high speed CCD

    SHIRAISHI YASUYUKI, Sano Kyosuke, Kitano Tomoya, Miura Hidekazu, Sasaki Kazumasa, Yambe Tomoyuki

    Transactions of Japanese Society for Medical and Biological Engineering 53 S201_03-S201_03 2015

    Publisher: Japanese Society for Medical and Biological Engineering

    DOI: 10.11239/jsmbe.53.S201_03  

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    Rotary blood pumps are commonly employed as circulatory support, which might cause changes in circulation in end organs. The purpose of this study was to develop a noninvasive and contactless system for measurement of peripheral perfusion by using a high-speed camera. A measurement system was designed to derive the amplitude of the green level (AGL). The static test of colour intensity was performed in vitro to verify the blood volume density in the materials. We employed a volume density model, which consisted of a polymer sponge under the different absorption condition using fresh goat blood. The sponge with blood was sandwiched between acrylic plates and the gap between them was varied by the linear table so that the density could be evaluated. The intensity of CCD data on the top flat plate was captured and analysed. As a result, the relationship between the density of blood and the CCD intensity could be evaluated under the LED lighting conditions. Therefore, it was indicated that the AGL could be reflected by the blood volume and the system by using a high-speed camera might be useful for measuring patients' perfusion under the pump support condition.

  49. Non Invasive Evaluation of the Renal blood flow during left ventricular assistance with the Non-pulsatile blood pump

    YAMBE TOMOYUKI, SHIRAISHI YASUYUKI, MIURA HIDEKAZU

    Transactions of Japanese Society for Medical and Biological Engineering 53 S128_02-S128_02 2015

    Publisher: Japanese Society for Medical and Biological Engineering

    DOI: 10.11239/jsmbe.53.S128_02  

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    Non pulsatile blood pump is one of the most important therapeutic option for the patients with profound heart failure. However, multiple organ failure has been the limiting factor for the prognosis of the patients after implantation. Non invasive measurements may be the good option to evaluate the organ function. Charge-Coupled Device image sensors will be one of the solution for the measurement with economical advantage. In this study, Charge-Coupled Device image sensors had been used for the evaluation of the renal blood flow in the animal experiments with left ventricular assistance using non pulsatile blood pump. As the results, useful evaluation of the renal blood flow had been embodied, suggesting the clinical usefulness of this device.

  50. Contraction Support for The Right Ventricle by A Shape Memory Alloy Fibered Artificial Myocardium Peer-reviewed

    Yasuyuki Shiraishi, Akihiro Yamada, Tomoyuki Yambe, Shintaro Katahira, Naoki Masaki, Yukihiro Hayatsu, Masatoshi Akiyama, Yoshikatsu Saiki, Dai Homma

    2015 10TH ASIAN CONTROL CONFERENCE (ASCC) 2015

    Publisher: IEEE

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    Mechanical cardiac support by using artificial organs improves the circulatory condition in the patients with heart ailure. However, the thrombotic and bleeding complications might be caused by the use of these artificial prosthetic internal organs because of their direct attachment with blood. We have been developing an implantable artificial myocardial assist device that can support the natural ventricular contraction from outside of the heart. A shape memory alloy fiber was employed for the implantable design of the myocardial assistance. In this study, we focused on the right ventricular assist by the artificial myocardium using shape memory alloy fibers. We fabricated a prototype of the right ventricular contraction support based on the hinge mechanism design with shape memory fibered actuators. Fundamental characteristics of the contractile effects of the design, as well as its deformation, were examined, and the hemodynamic changes were investigated in the acute animal experiments. As a result, the supporting depth from the ventricular wall increased to be 35 mm, and the volumetric assistance showed around 50 mL incremental assist by the changes in the displacement of the actuator.

  51. 東北文化学園専門学校における生体機能代行装置学実習 人工心肺実習26年間の歩み Peer-reviewed

    鈴木 一郎, 千葉 美樹, 富田 元沖, 宮本 美有希, 中畑 碧, 高橋 るみ, 佐々木 典子, 宇川 雅晴, 工藤 剛実, 小林 峰徳, 畠山 公一, 小出 芳夫, 相澤 康弘, 白石 泰之, 山家 智之, 菊地 徹, 出羽 仁

    体外循環技術 41 (4) 505-510 2014/12

    Publisher: (一社)日本体外循環技術医学会編集委員会

    ISSN:0912-2664

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    臨床工学技士養成校での人工心肺実習について報告する。生体機能代行装置学実習として実習動物を用いた人工心肺実習を東北文化学園専門学校にて1989年より継続し、授業の一環として生ある実習動物を用いて実際に人工心肺業務(人工心肺業務の準備、組立、操作、管理、モニタリングなど)・術野・薬剤・モニター・麻酔・心筋保護・記録などの役割を与えて人工心肺の操作を行っている。実習についての授業は3年生前期の4月から7月に実習ノートをもとに行い、前期に実習動物を用いた実習を行っている。実習の班編成は、1班12〜13名の人数で、午前と午後の2つの班で行っている。実際に学生たちが自主的に実習に向けた準備を行うことにより学生間の結束が強くなり、他のパートとの連携なしには成果を得られないことなどを実感し、実際に臨床の現場でのチーム医療の大切さを肌で感じているようである。26年間実習動物を用いた人工心肺の実習を行っているが、実際の心臓に触れ、心臓の動きを直に感じてもらい、学生一人ひとりが命の大切さを認識し、患者・他の医療従事者との連携の重要性、チーム医療の大切さを感じ取ってほしいと願い実習を継続している。(著者抄録)

  52. Preloading based needle insertion with a concave probe to enhance targeting in breast tissue Peer-reviewed

    Yo Kobayashi, Maya Hatano, Makiko Suzuki, Yasuyuki Shiraishi, Tomoyuki Yambe, Makoto Hashizume, Masakatsu G Fujie

    ROBOMECH Journal 1 (1) 2014/12/01

    Publisher: Springer International Publishing

    DOI: 10.1186/s40648-014-0017-4  

    ISSN:2197-4225

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    Target displacement cased by tissue deformation is a major technical challenge in ultrasound-guided needle insertion for breast tumor treatment or biopsy. We previously developed a preloading-based needle insertion method, which consists of a preloading phase and an insertion phase, and validated its placement accuracy. The present study furthered this research by focusing on a new concave preloading probe to enhance needle insertion targeting. With this probe, we evaluated the several probe size for different tumor diameters and locations to investigate the geometry effect on insertion accuracy. In this in vitro study, preloading-based needle insertion with concave probe of the same diameter as that of the tumor showed the highest placement accuracy for shallow tumors, while concave probe of a larger diameter than that of the tumor showed the highest placement accuracy for deep tumors. Overall, the concave preloading probe described in this study decreased needle placement error. Future research focused on its evaluation by structural analysis based on soft tissue modelling and deformation simulation.

  53. Tele-healthcare systems for end-of-life decision at home Peer-reviewed

    Makoto Yoshizawa, Hitoshi Ohuchi, Kenji Nunokawa, Kouichi Taniuchi, Norihiro Sugita, Makoto Abe, Noriyasu Homma, Tomoyuki Yambe

    Transactions of Japanese Society for Medical and Biological Engineering 52 15-SY-16 2014/08/17

    Publisher: Japan Soc. of Med. Electronics and Biol. Engineering

    DOI: 10.11239/jsmbe.52.SY-15  

    ISSN:1347-443X 1881-4379

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    Super aging society such as Japan would need tele-healthcare systems for home medical care to suppress medical cost inflation. In this situation, we have developed a tele-healthcare system for end-of-life decision at home using a wireless electrocardiograph combined with a smartphone and a sphygmogram signal extracted from an ordinary video camera. The experimental results have indicated that long term monitoring through the smartphone and a server will provide rich information on the patient's terminal status for doctors in remote locations. However, it is necessary to collect many clinical data to predict the timing of end-of-life more precisely.

  54. Estimation of subjective stress in university students using physiological response to psychological load Peer-reviewed

    Akira Tanaka, Makoto Yoshizawa, Tomoyuki Yambe

    Transactions of Japanese Society for Medical and Biological Engineering 52 20-SY-21 2014/08/17

    Publisher: Japan Soc. of Med. Electronics and Biol. Engineering

    DOI: 10.11239/jsmbe.52.SY-20  

    ISSN:1347-443X 1881-4379

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    In this study, the relationship between subjective score of mental stress and autonomic nervous response was investigated in order to develop the estimation method for evaluation of the level of mental stress. In proposed method, the changes in physiological parameters which represent autonomic nervous during psychological load ware focused. Physiological indices were recorded during psychological load such as watching slideshow including uncomfortable images or tiny “4x4 Sudoku” task in healthy university students. Multiple regression model in which target variable was subjective mental condition STAI was obtained using the measured physiological responses. The result revealed a good correlation between subjective value of state anxiety from STAI and the output of the model. The results indicated the possibility of the objective evaluation for mental stress though it is necessary to investigate the optimal psychological load for the evaluation.

  55. Preliminary examination of peripheral resistance in Kidney by using a high-speed CCD Peer-reviewed

    Kyosuke Sano, Tomoya Kitano, Yasuyuki Shiraishi, Hidekazu Miura, Akira Tanaka, Makoto Yoshizawa, Tomoyuki Yambe

    Transactions of Japanese Society for Medical and Biological Engineering 52 311-O-312 2014/08/17

    Publisher: Japan Soc. of Med. Electronics and Biol. Engineering

    DOI: 10.11239/jsmbe.52.O-311  

    ISSN:1347-443X 1881-4379

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    Pulsatility in aortic flow can be obtained with native ventricles even if the assist devices are rotary blood flow types. Therefore, it is anticipated that the pulsatile flow with centrifugal blood pumps might cause changes in peripheral perfusions. We have been establishing a new method of measuring peripheral perfusions by using a high speed CCD camera in order to diagnose blood flow in peripheral organs. In this study, we performed an animal experiment using a goat and examined renal circulation under the administration of vasodilator with two different types of blood flow measurements a laser Doppler tissue flow and the CCD. We also compared the peripheral impedance in each method as well as the renal input impedance calculated by the aortic pressure and electromagnetic flow waveforms. As a result, the longitudinal and characteristic impedance data decreased under the vasodilation condition in each renal peripheral perfusion analysis.

  56. The effect of control condition of ventricular assist device on the response of cardiac output to venous blood return Peer-reviewed

    Satomi Taniguchi, Akira Tanaka, Makoto Yoshizawa, Yasuyuki Shiraishi, Hidekazu Miura, Tomoya Kitano, Tomoyuki Yambe

    Transactions of Japanese Society for Medical and Biological Engineering 52 546-O-547 2014/08/17

    Publisher: Japan Soc. of Med. Electronics and Biol. Engineering

    DOI: 10.11239/jsmbe.52.O-546  

    ISSN:1347-443X 1881-4379

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    The cardiac functions including the autoregulation such as Frank-Starling preload response is depressed in heart failure. Although ventricular assist device (VAD) contributes to reduce ventricular load and increase cardiac output, the effect of VAD on depressed preload response has not become clear. In this study, the effect of control conditions and performance curve of blood pump on the preload sensitivity was investigated using numerical simulations. The preload sensitivity was defined as maximum change in cardiac output when right atrial pressure was changed from circulatory equilibrium in the simulations. Furthermore, animal experiment was performed in order to verify the result of the simulations. The preload sensitivity of pump flow changed depending on pump characteristic. Conversely, that of total flow was almost the same with various pump characteristics at partial bypass condition. Results indicated that it is necessary to introduce some active control to improve the sensitivity.

  57. Role of nurses in domiciliary treatment for patient with implantable left ventricular assist device Peer-reviewed

    Miki Akiba, Akiko Kusakari, Mitsuyo Katagiri, Tomoyuki Yambe, Masatoshi Akiyama, Shunsuke Kawamoto, Yoshikatsu Saiki

    Transactions of Japanese Society for Medical and Biological Engineering 52 86 2014/08/17

    Publisher: Japan Soc. of Med. Electronics and Biol. Engineering

    DOI: 10.11239/jsmbe.52.SY-86  

    ISSN:1347-443X 1881-4379

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    [Backgrounds]Treatment for end-stage heart failure has been shifting from inpatient care to domiciliary treatment according to the commence of health insurance reimbursement for implantable left ventricular assist device (LVAD). Majority of patients with LVAD treatment are able to enjoy better quality of life and rehabilitation in society, which was not achievable with conventional medical treatment. [Current status and management] We established the ventricular assist device center at Tohoku University Hospital in April, 2013, and have dedicated ourselves to manage domiciliary treatment for patients with LVAD. There have been currently three so-called LVAD nurses belonging to the VAD center, and all are qualified with a certificate for LVAD specialist. The LVAD nurses play a role as a contact person and a coordinator for outpatient clinic for patients and their family including emergent occasion. They are also in charge of home anti-coagulant management utilizing a coagucheck XS○R personal. Infection control of drive-line exit site is another area of important management by them. When infection is suspected, the patients are required to send them some photographs of the exit site which are then meticulously assessed along with the updated information on each patient obtained over the phone. Selected surgical dressings and instruction on sterilization technique for patients are also provided by the LVAD nurses. [Summary] The number of patients requiring LVAD treatment has been increasing and the number of available devices has also been expanding over the last three years. Accordingly, medical professionals are requested to provide individualized care and management for each patient. The VAD center has undoubtedly played a central role to enable the patients with LVAD to live their lives at home by a team effort with integrated knowledge and expertise shared among LVAD specialists.

  58. High risk弓部大動脈瘤症例に対するTotal de-branch TEVARの成績と手術関連合併症の検討

    齋藤 武志, 熊谷, 紀一郎, 川本, 俊輔, 本吉, 直孝, 河津, 聡, 早津, 幸弘, 松尾, 諭志, 鈴木, 智之, 齋木 佳克

    日本血管外科学会雑誌 23 (2) 373-373 2014

    Publisher: None

    ISSN:0918-6778

    eISSN:1881-767X

  59. Preliminary study on contactless evaluation of peripheral perfusion during rotary blood pump support Peer-reviewed

    Kyosuke Sano, T. Kitano, Y. Shiraishi, A. Tanaka, M. Yoshizawa, T. Yambe

    IFMBE Proceedings 43 444-447 2014

    Publisher: Springer Verlag

    DOI: 10.1007/978-3-319-02913-9_113  

    ISSN:1680-0737

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    Rotary blood pumps are commonly used for circulatory support in the patients with severe heart failure. We proposed a new evaluation method of peripheral perfusions by using a charge-coupled device. There is increasing case for heart rate or pulse wave detection capabilities from the record by charge-coupled devices, such as digital cameras. In this study, we performed animal experiments in goats and examined a quantitative investigation method of peripheral circulation in the organs by a noninvasive and contactless measurement using a digital high speed camera. Measurements of peripheral blood flow in the organs were carried out in these two steps: a) the validation of the chargecoupled device detection with the laser blood flow meter in the animal experiments, and b) the examination of peripheral perfusing during a centrifugal blood pump assistance. A simple capture of the goat’s peripherals, such as the surface of kidney, lung or skins, allowed a measurement of how the RGB components were distributed within the organ peripherals. The color components of the images were obtained with the high speed still camera (Casio, EX-F1) at 300 fps. Tissue perfusion in the vicinity of the location was also measured by the laser blood flow meter (Omega Flow, FLO-C1) for validation. Then a centrifugal blood pump (Evaheart, SunMedical Technology Research Corp., Japan) was employed and we examined its effects on peripheral blood flow changes. As a result, we could obtain the pulse wave changes by the analysis of the distribution of green light histogram levels derived from the data. Therefore, it was suggested that our approach of the evaluation of peripheral blood flow distribution by a simple shot of digital cameras might achieve the evaluation of the effects of surgical treatment on peripheral organs with the rotary blood pump support.

  60. Thoughts and Progress Peer-reviewed

    Takashi Yamane Ryo, Kosaka Masahiro, NishidaOsamu Maruyama, Yoshihiro Yamamoto, Katsuyuki Kuwana, Hiroshi Kawamura, Yasuyuki Shiraishi Tomoyuki YambeYoshiyuki Sankai, Tatsuo Tsutsui

    Artificial Organs 217-225 2013/04

  61. High risk弓部大動脈瘤症例に対するde-branch TEVARの変遷と手術成績

    齋藤 武志, 熊谷, 紀一郎, 川本, 俊輔, 安達, 理, 河津, 聡, 鈴木, 智之, 齋木 佳克

    日本血管外科学会雑誌 22 (2) 470-470 2013

    Publisher: None

    ISSN:0918-6778

    eISSN:1881-767X

  62. 大動脈解離に対し、Bioglueを使用した人工血管置換術の長期成績の検討

    神田 桂輔, 川本, 俊輔, 鈴木, 智之, 齋藤, 武志, 熊谷, 紀一郎, 齋木 佳克

    日本血管外科学会雑誌 22 (2) 425-425 2013

    Publisher: None

    ISSN:0918-6778

    eISSN:1881-767X

  63. A Great Impact of Green Video Signals on Tele-Healthcare in Daily Life, Especially for Rural or Disaster Areas

    Yoshizawa Makoto, Tanaka Akira, Sugita Norihiro, Abe Makoto, Homma Noriyasu, Obara Kazuma, Yambe Tomoyuki

    BME 51 M-55-M-55 2013

    Publisher: Japanese Society for Medical and Biological Engineering

    DOI: 10.11239/jsmbe.51.M-55  

    ISSN:1347-443X

  64. Evaluation of Baroreflex System for Elderly People in Disaster Areas Using Electrocardiogram and Plethysmogram

    Yoshizawa Makoto, Tanaka Akira, Sugita Norihiro, Abe Makoto, Homma Noriyasu, Konno Satoshi, Yambe Tomoyuki

    BME 51 M-9-M-9 2013

    Publisher: Japanese Society for Medical and Biological Engineering

    DOI: 10.11239/jsmbe.51.M-9  

    ISSN:1347-443X

  65. A new control method depending on primary phase angle of transcutaneous energy transmission system for artificial heart Peer-reviewed

    H. Miura, I. Saito, F. Sato, Y. Shiraishi, T. Yambe, H. Matsuki

    Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS 5723-5726 2013

    DOI: 10.1109/EMBC.2013.6610850  

    ISSN:1557-170X

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    A new control method for stabilizing output voltage of the transcutaneous energy transmission system for artificial heart is proposed. This method is primary side, is outside of the body, which is not depending on a signal transmission system from the implanted device. The impedance observed from primary side changes from inductive to capacitive and the output voltage decreases drastically when the output current is large and the coupling factor is higher than that of the optimal condition. In this case, the driving frequency should be changed to higher so that the phase angle of the primary impedance is zero degree. The preliminary examination showed that this control method can enhance the output voltage limit to twice and the feasibility of the primary side control. © 2013 IEEE.

  66. Reentrant Ventricular Outflow Tract Tachycardia Arising from Focal Scar Detected by Delayed Enhancement Magnetic Resonance Imaging Peer-reviewed

    Yoshihiro Yamashina, Tetsuo Yagi, Akio Namekawa, Akihiko Ishida, Hirokazu Sato, Takashi Nakagawa, Manjirou Sakuramoto, Eiji Sato, Tomoyuki Yambe

    PACE-PACING AND CLINICAL ELECTROPHYSIOLOGY 35 (12) E349-E352 2012/12

    Publisher: WILEY-BLACKWELL

    DOI: 10.1111/j.1540-8159.2012.03368.x  

    ISSN:0147-8389

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    A 58-year-old man was referred to our emergency room with hemodynamically unstable sustained ventricular tachycardia (VT). The morphology of the VT exhibited a left bundle branch block and inferior axis deviation. He had no past history of cardiovascular disease. Echocardiography, cardiac catheterization, cardiac biopsy, gallium scintigram, myocardial scintigram, T1,T2-weighted magnetic resonance imaging (MRI), and gadolinium-enhanced cine MRI did not detect any structural heart disease or abnormal cardiac function. However, delayed-enhancement MRI (DE-MRI) detected a focal intramural scar within the septal ventricular outflow tract. An electrophysiological study revealed a sustained VT with several morphologies and the entrainment phenomenon. Radiofrequency catheter ablation to the site corresponding to the focal scar detected by DE-MRI successfully eliminated the VT. (PACE 2012;35:e349e352)

  67. Survey of blood pump diaphragm damage in the NIPRO-ventricular assist device Peer-reviewed

    Koichi Kashiwa, Takashi Nishimura, Aoi Nakahata, Naoki Momose, Chinori Umeda, Hitoshi Kubo, Hisayoshi Tamai, Koichiro Kinugawa, Hideo Adachi, Atsushi Yamaguchi, Tomoyuki Yambe, Toshiyuki Katohgi, Shunei Kyo, Minoru Ono

    JOURNAL OF ARTIFICIAL ORGANS 15 (4) 341-346 2012/12

    Publisher: SPRINGER JAPAN KK

    DOI: 10.1007/s10047-012-0657-1  

    ISSN:1434-7229

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    We surveyed the incidence of blood pump diaphragm damage (rupture or crack) in the NIPRO-ventricular assist device (VAD). In the cases in which rupture or suspected blood pump crack was detected, we disassembled the pumps to visually check the condition of the diaphragm after replacement or use. Of 366 blood pumps surveyed, diaphragm damage was observed in 2.7 %. The duration of use of the blood pumps with diaphragm damage was significantly longer than that of pumps without damage. The incidence of diaphragm damage increased with longer duration of use. On the basis of these findings, blood pump diaphragm damage in the NIPRO-VAD may be associated with duration of use. However, some blood pumps were used for prolonged periods without diaphragm damage. All blood pumps with damage had a crack in the diaphragm on the air chamber side near the diaphragm-housing (D-H) junction. Cracks were not found in any specific part of the diaphragm. In blood pumps with diaphragm rupture, the crack had a through-hole reaching the blood-contacting surface. Although we were unable to identify the causes of the cracks, it is suggested that when a crack appears in the diaphragm it will gradually expand and eventually lead to rupture. If a crack is detected in a blood pump, we advocate replacing the pump before it grows. When the NIPRO-VAD is used, it is necessary to keep in mind that blood pump diaphragm damage may occur.

  68. Application of a Telemedical Tool in an Isolated Island and a Disaster Area of the Great East Japan Earthquake Peer-reviewed

    Makoto Yoshizawa, Tomoyuki Yambe, Norihiro Sugita, Satoshi Konno, Makoto Abe, Noriyasu Homma, Futoshi Takei, Katsuhiko Yokota, Yoshifumi Saijo, Shin-ichi Nitta

    IEICE TRANSACTIONS ON COMMUNICATIONS E95B (10) 3067-3073 2012/10

    Publisher: IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG

    DOI: 10.1587/transcom.E95.B.3067  

    ISSN:0916-8516

    eISSN:1745-1345

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    The present paper has reported a case study of the "Electronic Doctor's Bag" which is a telemedical tool for home-visit medical services using the mobile communications environment in an isolated island and a disaster area hit by the tsunami. Clinical trials performed for 20 patients around a clinic in Miyako Island indicated that the communication functions of the proposed system were highly evaluated by patients as well as medical staff's. However, the system still has room for further improvement in operability, portability and mobile communication environment. The experience at the shelter in Kesennuma City suggested that mobile healthcare tools such as the proposed system will be strongly required when there are no or only paramedical staffs after leaving of emergency medical staffs.

  69. Medical Responses Following the Sendai Quake (East Japan Earthquake, March 11, 2011) Peer-reviewed

    Tomoyuki Yambe, Muneichi Shibata, Taketada Sumiyoshi, Yoshiaki Mibiki, Noboru Osawa, Yoshiaki Katahira, Minoru Yambe, Kou-ichi Tabayashi, Masanori Yamashina, Eiji Sato, Shinichi Sato, Tetsuo Yagi, Makoto Watanabe, Yoshihira Akinno, Masanori Munakata, Naoki Owada, Masatoshi Akiyama, Yoshikatsu Saiki, Norihiro Sugita, Makoto Yoshizawa

    ARTIFICIAL ORGANS 36 (8) 760-763 2012/08

    Publisher: WILEY-BLACKWELL

    DOI: 10.1111/j.1525-1594.2012.01522.x  

    ISSN:0160-564X

    eISSN:1525-1594

  70. New implantable therapeutic device for the control of an atrial fibrillation attack using the Peltier element. Peer-reviewed

    Yambe Tomoyuki, Sumiyoshi Taketada, Koga Chihiro, Shiraishi Yasuyuki, Miura Hidekazu, Sugita Norihiro, Tanaka Akira, Yoshizawa Makoto

    Conf Proc IEEE Eng Med Biol Soc 2012 5741-5744 2012/08

    DOI: 10.1109/EMBC.2012.6347298  

  71. A New Transcutaneous Bidirectional Communication for Monitoring Implanted Artificial Heart Using the Human Body as a Conductive Medium. Peer-reviewed

    Okamoto Eiji, Kato Yoshikuni, Seino Kazuyuki, Miura Hidekazu, Shiraishi Yasuyuki, Yambe Tomoyuki, Mitamura Yoshinori

    Artif Organs 10 2012/07/19

    DOI: 10.1111/j.1525-1594.2012.01480.x  

  72. Left heart bypass support with the Rotaflow Centrifugal Pump(A (R)) as a bridge to decision and recovery in an adult Peer-reviewed

    Koichi Kashiwa, Takashi Nishimura, Aya Saito, Hitoshi Kubo, Aoi Fukaya, Hisayoshi Tamai, Tomoyuki Yambe, Shunei Kyo, Minoru Ono

    JOURNAL OF ARTIFICIAL ORGANS 15 (2) 207-210 2012/06

    Publisher: SPRINGER TOKYO

    DOI: 10.1007/s10047-012-0632-x  

    ISSN:1434-7229

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    Since left heart bypass or biventricular circulatory assist with an extracorporeal centrifugal pump as a bridge to decision or recovery sometimes requires long-time support, the long-term durability of extracorporeal centrifugal pumps is crucial. The Rotaflow Centrifugal Pump(A (R)) (MAQUET Cardiopulmonary AG, Hirrlingen, Germany) is one of the centrifugal pumps available for long-term use in Japan. However, there have been few reports of left heart bypass or biventricular circulatory support over the mid-term. This is a case report of left heart bypass support with the Rotaflow Centrifugal Pump(A (R)) as a bridge to decision and recovery for an adult patient who could not be weaned from cardiopulmonary bypass and percutaneous cardiopulmonary support after cardiac surgery. We could confirm that the patient's consciousness level was normal; however, the patient could not be weaned from the left heart bypass support lasting 1 month. Therefore, the circulatory assist device was switched to the extracorporeal Nipro ventricular assist device (VAD). This time, left heart bypass support could be maintained for 30 days using a single Rotaflow Centrifugal Pump(A (R)). There were no signs of hemolysis during left heart bypass support. The Rotaflow Centrifugal Pump(A (R)) itself may be used as a device for a bridge to decision or recovery before using a VAD in cardiogenic shock patients.

  73. Focal atrial tachycardia arising from the cavotricuspid isthmus with saw-tooth morphology on the surface ECG: electrocardiographic and electrophysiologic characteristics Peer-reviewed

    Hirokazu Sato, Tetsuo Yagi, Akio Namekawa, Akihiko Ishida, Yoshihiro Yamashina, Takashi Nakagawa, Manjirou Sakuramoto, Eiji Sato, Tomoyuki Yambe

    JOURNAL OF INTERVENTIONAL CARDIAC ELECTROPHYSIOLOGY 33 (2) 127-133 2012/03

    Publisher: SPRINGER

    DOI: 10.1007/s10840-011-9622-9  

    ISSN:1383-875X

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    Background Limited information is available about focal atrial tachycardia (AT) arising from cavotricuspid isthmus (CTI). Objective The purpose of this study is to evaluate the electrocardiographic and electrophysiologic characteristics of a focal AT arising from the CTI. Methods From a consecutive series of 92 patients undergoing radiofrequency catheter ablation (RFCA) for focal AT, three (4.4%) patients (three men) with a focal AT arising from the CTI were studied. Results The median age was 71 years (range, 50 to 81 years). None of the patients had a history of CTI-dependent atrial flutter. The electrocardiogram (ECG) of a focal AT showed a significant negative F-wave in the inferior leads. Focal AT could be reproducibly initiated and terminated with programmed stimulation. The focus of the tachycardia was localized to the central isthmus in two and the paraseptal isthmus in one patient. The median tachycardia cycle length was 275 ms (range, 260 to 310 ms). In two patients, the focal AT was adenosine insensitive. In all of the patients, tachycardia was entrained from multiple right atrial sites, including the earliest activation site. RFCA was acutely successful in all patients. Long-term success was achieved in all patients over the median follow-up of 18 months (range, 6 to 33 months). Conclusions Cavotricuspid isthmus is an uncommon site of origin for focal AT. This focal AT has unique electrocardiographic characteristics such as saw-tooth morphology on ECG and is suggested to be caused by a focal reentrant circuit located at the CTI. Long-term success is achieved with focal ablation.

  74. Engineering analysis of the effects of bulging sinuses in a newly designed pediatric pulmonary heart valve on hemodynamic function. Peer-reviewed

    Ichiro Suzuki, Yasuyuki Shiraishi, Shota Yabe, Yusuke Tsuboko, Telma Keiko Sugai, Ken Matsue, Takeyoshi Kameyama, Yoshifumi Saijo, Takashi Tanaka, Yoshihiro Okamoto, Zhonggang Feng, Takako Miyazaki, Masaaki Yamagishi, Makoto Yoshizawa, Mitsuo Umezu, Tomoyuki Yambe

    Journal of artificial organs : the official journal of the Japanese Society for Artificial Organs 15 (1) 49-56 2012/03

    DOI: 10.1007/s10047-011-0609-1  

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    The purpose of this study was to examine the hemodynamic characteristics of expanded polytetrafluoroethylene (ePTFE) pulmonary valves with bulging sinuses quantitatively in a pediatric pulmonary mechanical circulatory system designed by us, in order to propose the optimal design for clinical applications. In this study, we developed a pediatric pulmonary mock circulation system, which consisted of a pneumatic right ventricular model, a pulmonary heart valve chamber, and a pulmonary elastic compliance tubing with resistive units. The hemodynamic characteristics of four different types of ePTFE valves and a monoleaflet mechanical heart valve were examined. Relationships between the leaflet movements and fluid characteristics were evaluated based on engineering analyses using echocardiography and a high-speed video camera under the pediatric circulatory conditions of the mock system. We successfully performed hemodynamic simulations in our pediatric pulmonary circulatory system that could be useful for quantitatively evaluating the pediatric heart valves. In the simulation study, the ePTFE valve with bulging sinuses exhibited a large eddy in the vicinity of the leaflets, whereas the straight tubing exhibited turbulent flow. The Reynolds number obtained in the valve with bulging sinuses was calculated to be 1667, which was smaller than that in the straight tubing (R (e) = 2454).The hemodynamic characteristics of ePTFE pediatric pulmonary heart valves were examined in our mock circulatory system. The presence of the bulging sinuses in the pulmonary heart valve decreased the hydrodynamic energy loss and increased the systolic opening area. Based on an in vitro experiment, we were able to propose an optimal selection of pulmonary valve design parameters that could yield a more sophisticated pediatric ePTFE valve shape.

  75. Cardio-Ankle Vascular Index in Heterozygous Familial Hypercholesterolemia. Peer-reviewed

    Soska V, Dobsak P, Dusek L, Shirai K, Jarkovsky J, Novakova M, Brhel P, Stastna J, Fajkusova L, Freiberger T, Yambe T

    J Atheroscler Thromb 無 2012/01/12

    DOI: 10.5551/jat.9639  

  76. Nonlinear Reaction Force Analysis for Characterization of Breast Tissues Peer-reviewed

    Mariko Tsukune, Yo Kobayashi, Takeharu Hoshi, Yasuyuki Shiraishi, Tomoyuki Miyashita, Tomoyuki Yambe, Masakatu G. Fujie

    COMPUTER AIDED SURGERY 3 125-134 2012

    Publisher: SPRINGER

    ISSN:1867-2914

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    This paper addresses a diagnostic palpation system based on the measurement of nonlinear elasticity. An indentation probe is used to press against breast tissue. Then, the measured reaction force is used to estimate the parameters of nonlinear elasticity, which enables the identification of tissue type, such as fat, muscle, mammary gland or tumor. Here, we present the basic concept of our study and preliminary experimental and simulation results from pilot studies. More specifically, we measured the nonlinear response of reaction force using the breast of a goat. In addition, we also simulated the reaction force using nonlinear biomechanical simulation with several tissue types. Large differences in reaction force occur only in the nonlinear range in both experimental and simulation situations. Our results confirmed the feasibility of our concept.

  77. Development and Clinical Application of a Precise Temperature-Control Device as an Alternate for Conventional Moxibustion Therapy Peer-reviewed

    Shin Takayama, Shigeru Takashima, Junnosuke Okajima, Masashi Watanabe, Tetsuharu Kamiya, Takashi Seki, Miyako Yamasaki, Nobuo Yaegashi, Tomoyuki Yambe, Shigenao Maruyama

    EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2012 426829-426829 2012

    Publisher: HINDAWI LTD

    DOI: 10.1155/2012/426829  

    ISSN:1741-427X

    eISSN:1741-4288

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    Moxibustion therapy has been used in East Asian medicine for more than a thousand years. However, there are some problems associated with this therapy in clinical practice. These problems include lack of control over the treatment temperature, emission of smoke, and uneven temperature distribution over the treatment region. In order to resolve these problems, we developed a precise temperature-control device for use as an alternate for conventional moxibustion therapy. In this paper, we describe the treatment of a single patient with paralytic ileus that was treated with moxibustion. We also describe an evaluation of temperature distribution on the skin surface after moxibustion therapy, the development of a heat-transfer control device (HTCD), an evaluation of the HTCD, and the clinical effects of treatment using the HTCD. The HTCD we developed can heat the skin of the treatment region uniformly, and its effect may be equivalent to conventional moxibustion, without the emission of smoke and smell. This device can be used to treat ileus, abdominal pain, and coldness of abdomen in place of conventional moxibustion in modern hospitals.

  78. Cardio-Ankle Vascular Index in Heterozygous Familial Hypercholesterolemia Peer-reviewed

    Vladimir Soska, Petr Dobsak, Ladislav Dusek, Kohji Shirai, Jiri Jarkovsky, Marie Novakova, Petr Brhel, Jana Stastna, Lenka Fajkusova, Tomas Freiberger, Tomoyuki Yambe

    JOURNAL OF ATHEROSCLEROSIS AND THROMBOSIS 19 (5) 453-461 2012

    Publisher: JAPAN ATHEROSCLEROSIS SOC

    DOI: 10.5551/jat.9639  

    ISSN:1340-3478

    eISSN:1880-3873

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    Aim: The cardio-ankle vascular index (CAVI) is a new non-invasive marker of arterial stiffness and atherosclerosis. The purpose of this study was to compare CAVI in patients with heterozygous familial hypercholesterolemia (FH) and in healthy controls. Methods: 82 FH subjects (27 males, 65 females), aged 53.7 +/- 13.6 years without clinical symptoms of cardiovascular diseases and 359 healthy controls (121 males, 238 females), aged 43.9 +/- 14.9 years, were examined. CAVI was measured using the system VaSera (R) 1500. Results: CAVI in FH patients was significantly higher (8.0 +/- 1.4) than in healthy subjects (7.5 +/- 1.3) p=0.002; however, age, sex and BMI adjusted CAVI did not differ significantly (p=0.061) between the FH group (7.5, CI: 7.3; 7.7) and control group (7.7, CI: 7.6; 7.7). Conclusion: The study showed no significant difference in CAVI between heterozygous FH and healthy controls.

  79. Prevalence and characteristics of idiopathic right ventricular outflow tract arrhythmias associated with J-waves Peer-reviewed

    Yoshihiro Yamashina, Tetsuo Yagi, Akio Namekawa, Akihiko Ishida, Hirokazu Sato, Takashi Nakagawa, Manjirou Sakuramoto, Eiji Sato, Tomoyuki Yambe

    EUROPACE 13 (12) 1774-1780 2011/12

    Publisher: OXFORD UNIV PRESS

    DOI: 10.1093/europace/eur256  

    ISSN:1099-5129

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    Aim The arrhythmogenic relationship between the presence of J-waves during sinus rhythm and idiopathic ventricular tachycardia (VT) or pre-mature ventricular contractions (PVCs) originating from the right ventricular outflow tract (RVOT) has not been reported. The aim of this study was to investigate the prevalence and characteristics of idiopathic RVOT-VT/PVCs associated with J-waves. Methods and results The study enrolled 138 consecutive idiopathic RVOT-VT/PVC patients undergoing radiofrequency catheter ablation (RFCA) and 276 age-and gender-matched control subjects. The prevalence of J-waves was assessed in each cohort, and the clinical and electrophysiological data were compared between the RVOT-VT/PVC patients with J-waves (J-RVOT-VT/PVC group) and those without (non-J-RVOT-VT/PVC group). J-waves were more common among patients with idiopathic RVOT-VT/PVCs than among the matched control subjects (40 vs. 16% P &lt; 0.001). The J-RVOT-VT/PVC group had a higher incidence of sustained VT (25 vs. 5%, P &lt; 0.01), shorter VT cycle length (302 +/- 57 vs. 351 +/- 58 ms, P &lt; 0.001), and more episodes of syncope (25 vs. 2%, P &lt; 0.001) than did the non-J-RVOT-VT/PVC group. However, no patients demonstrated any ventricular fibrillation (VF) or cardiac sudden death in either group. Conclusions There was a high prevalence of J-waves in the idiopathic RVOT-VT/PVC patients referred for RFCA. Although patients with idiopathic RVOT arrhythmias associated with J-waves might have a more enhanced arrhythmogenicity than those without J-waves, the significance of those J-waves was limited in terms of the prognosis and VF.

  80. 推定流量による定常流型補助人工心臓の流量制御 Peer-reviewed

    針生健太郎, 田中明, SugaiTelma Keiko, 白石泰之, 吉澤誠, 山家智之

    人工臓器 40 (2) S160-S160 2011/10

  81. 心房細動治療用デバイスの熱応答の基礎検討 Peer-reviewed

    古賀千尋, 住吉剛忠, 三浦英和, 劉紅箭, 神谷蔵人, 志賀卓弥, HashemMohammed, SugaiTelma Keiko, 陳炯旬, 橋本尚, 山田昭博, 大沢上, 佐藤尚, 白石泰之, 山家智之

    人工臓器 40 (2) S146-S146 2011/10

  82. 生体僧房弁モデルを用いた力学検討に基づく人工乳頭筋設計 Peer-reviewed

    橋本尚, 白石泰之, SugaiTelma, 志賀卓弥, 神谷蔵人, HashemMohamed, 北野智哉, 古賀千尋, 陳炯旬, 山田昭博, 坪子侑佑, 森谷葵, 三浦英和, 西條芳文, 山家智之, 本間大

    人工臓器 40 (2) S138-S138 2011/10

  83. 完全人工心臓用カスケードポンプ(ACCEL PUMP)の左心用ポンプの評価 Peer-reviewed

    福長一義, 阿部裕輔, 山家智之, 巽英介, 増澤徹, 山根隆志, 妙中義之, 井街宏, 舟久保昭夫, 福井康裕

    人工臓器 40 (2) S136-S136 2011/10

  84. ニプロ補助人工心臓の駆動チューブの屈曲を検知させる方法についての研究 Peer-reviewed

    柏公一, 西村隆, 杉谷弘文, 深谷碧, 久保仁, 玉井久義, 馬場敦, 白石泰之, 山家智之, 許俊鋭, 小野稔

    人工臓器 40 (2) S128-S128 2011/10

  85. MERAモノピボット遠心血液ポンプの血液適合性評価 Peer-reviewed

    丸山修, 小阪亮, 西田正浩, 筒井達夫, 井街宏, 山家智之, 山根隆志

    人工臓器 40 (2) S127-S127 2011/10

  86. MERAモノピボット遠心血液ポンプの動物実験評価 Peer-reviewed

    山根隆志, 丸山修, 西田正浩, 小阪亮, 山本好宏, 桑名克之, 白石泰之, 山家智之, 筒井達夫

    人工臓器 40 (2) S127-S127 2011/10

  87. 小型遠心ポンプを用いた定常流全置換型人工心臓の小型軽量化を目指した研究開発 Peer-reviewed

    三浦英和, 陳炯旬, 志賀卓弥, 白石泰之, スガイ・テルマ・ケイコ, 劉紅箭, 山家智之

    人工臓器 40 (2) S121-S121 2011/10

  88. 小児用新型肺動脈人工弁設計における最適化のための新しい設計の基礎検討 Peer-reviewed

    坪子侑佑, 鈴木一郎, 白石泰之, SugaiTelma Keiko, 北野智哉, 山田昭博, 志賀卓弥, 神谷蔵人, 劉江箭, 三浦英和, 西條芳文, 山家智之, 松尾諭志, 齋木佳克, 梅津光生, 宮崎隆子, 山岸正明

    人工臓器 40 (2) S118-S118 2011/10

  89. 慢性心疾患患者リハビリテーションにおける電気的筋肉刺激併用運動トレーニング Invited

    DobsakPetr, HomolkaPavel, SpinarovaLenka, VitovecJiri, JancikJiri, VaskuJaromir, 上月正博, 山家智之, 磯山隆, 馬場敦, 井街宏, SiegelovaJarmila

    人工臓器 40 (2) S109-S109 2011/10

  90. 遠心ポンプ型全置換型人工心臓における拍動流の椎骨動脈と腎動脈血流測定 Peer-reviewed

    志賀卓弥, 三浦英和, 陳炯旬, 白石泰行, 劉紅箭, SugaiTelma K, HashemMohamed Omran, 古賀千尋, 橋本尚, 山田昭博, 坪子侑佑, 森谷葵, 山家智之

    人工臓器 40 (2) S69-S69 2011/10

  91. 人体を通信媒体とする経皮的情報通信の動物実験評価 Peer-reviewed

    加藤良都, 岡本英治, 情野和幸, 三浦英和, 白石泰之, 山家智之, 三田村好矩

    人工臓器 40 (2) S63-S63 2011/10

  92. 日本発の人工臓器技術 スマートアクチュエータを利用した人工心筋 Peer-reviewed

    白石泰之, 秋山正年, 西條芳文, SugaiTelma Keiko, 北野智哉, 金子芳一, OmranMohamed Hashem, 山田昭博, 三浦英和, 志賀卓弥, 神谷蔵人, 森田紀代造, 山岸正明, TozziPiergiorgio, 梅津光生, 本間大, 齋木佳克, 山家智之

    人工臓器 40 (2) S26-S26 2011/10

  93. 震災診療支援のための電子診療鞄 Peer-reviewed

    山家智之, 吉澤誠, 柴田宗一, 八木哲夫, 片平美明

    日本高血圧学会総会プログラム・抄録集 34回 579-579 2011/10

  94. 東北大震災避難所における自律神経機能診断のための電子診療鞄 Peer-reviewed

    山家智之, 柴田宗一, 片平美明, 秋野能久

    日本自律神経学会総会プログラム・抄録集 64回 101-101 2011/10

  95. 虚血モデルマウスにおける血管内皮増殖因子受容体分布の生体内分子イメージング Peer-reviewed

    濱田庸, 権田幸祐, 佐藤成, 山家智之, 里見進, 大内憲明

    脈管学 51 (Suppl.) S99-S99 2011/09

  96. In vivo imaging of the molecular distribution of the VEGF receptor during angiogenesis in a mouse model of ischemia Peer-reviewed

    Yoh Hamada, Kohsuke Gonda, Motohiro Takeda, Akira Sato, Mika Watanabe, Tomoyuki Yambe, Susumu Satomi, Noriaki Ohuchi

    BLOOD 118 (13) E93-E100 2011/09

    Publisher: AMER SOC HEMATOLOGY

    DOI: 10.1182/blood-2010-12-322842  

    ISSN:0006-4971

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    Vascular endothelial growth factor (VEGF) plays a critical role in angiogenesis and has been applied to medical therapy. However, because vascular imaging at the molecular level is impossible, the detailed in vivo dynamics of VEGF and its receptor (VEGFR) remain unknown. In this study, to understand the molecular distribution of VEGF and the VEGFR, we prepared ischemic mice with a new surgical method and induced angiogenesis in the gastrocnemius muscle. Then, we made a VEGF-conjugated fluorescence nanoparticle and performed staining of VEGFR-expressing cells with the fluorescent probe, demonstrating the high affinity of the probe for VEGFR. To observe the physiologic molecular distribution of VEGFR, we performed in vivo single-particle imaging of gastrocnemius in the ischemic leg with the fluorescent probe. The results suggested that only a 3-fold difference of VEGFR distribution is involved in the formation of branched vasculature in angiogenesis, although previous ex vivo data showed a 13-fold difference in its distribution, indicating that a method inducing a several-fold local increase of VEGFR concentration may be effective in generating site-specific angiogenesis in ischemic disease. This new in vivo imaging of ischemic mice could make useful contributions to understanding the mechanisms of angiogenesis and to developing a VEGFR-related drug. (Blood. 2011;118(13):e93-e100)

  97. ヘリカルフロー遠心ポンプを用いた完全置換型無拍動人工心臓における心房収縮 Peer-reviewed

    山家智之

    日本心臓病学会誌 6 (Suppl.I) 505-505 2011/08

  98. 患者自信が自分で判断して必要時に体外から駆動させる右心補助循環装置 Peer-reviewed

    山家智之, 白石泰之, 三浦英和, 斎木佳克

    日本心臓病学会誌 6 (Suppl.I) 331-331 2011/08

  99. 3D映像視聴による自律神経への影響 循環調節系の変化と3D映像視聴 Peer-reviewed

    田中明, 杉田典大, 吉澤誠, 山家智之

    自律神経 48 (3) 211-213 2011/06

  100. Short-term effects of acupuncture on open-angle glaucoma in retrobulbar circulation: additional therapy to standard medication. Peer-reviewed

    Takayama Shin, Seki Takashi, Nakazawa Toru, Aizawa Naoko, Takahashi Seri, Watanabe Masashi, Izumi Masayuki, Kaneko Soichiro, Kamiya Tetsuharu, Matsuda Ayane, Kikuchi Akiko, Yambe Tomoyuki, Yoshizawa Makoto, Nitta Shin-Ichi, Yaegashi Nobuo

    Evid Based Complement Alternat Med 2011 157090-157090 2011/04

    DOI: 10.1155/2011/157090  

  101. Effects of Metabolic Syndrome on Cardio-Ankle Vascular Index in Middle-Aged and Elderly Chinese Peer-reviewed

    Hongjian Liu, Xiumin Zhang, Xiaoli Feng, Jinghua Li, Ming Hu, Tomoyuki Yambe

    METABOLIC SYNDROME AND RELATED DISORDERS 9 (2) 105-110 2011/04

    Publisher: MARY ANN LIEBERT INC

    DOI: 10.1089/met.2010.0019  

    ISSN:1540-4196

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    Metabolic syndrome is characterized by multiple risk factors and is associated with increased risk of diabetes and cardiovascular disease. The rapid change in the lifestyle and food habits of Chinese people has resulted in metabolic syndrome becoming one of the most widespread health challenges in China. Recently, the cardioankle vascular index (CAVI) was developed as a new parameter reflecting arterial stiffness and providing an index of vascular status. The purpose of this study was to investigate the effect of metabolic syndrome on CAVI. A total of 222 Chinese subjects aged 50-92 years participated in this study. We measured CAVI and examined blood samples to define metabolic syndrome according to the International Diabetes Federation criteria. CAVI in the subjects with abnormal waist circumference was significantly higher than that obtained in the normal subjects (P&lt;0.01). In the abnormal high-density lipoprotein cholesterol (HDL-C) group, CAVI was significantly increased (P&lt;0.01) compared to the normal HDL-C group. CAVI showed a positive correlation with waist circumference and increased significantly with the number of metabolic syndrome components. In conclusion, subjects with metabolic syndrome have a high CAVI that indicated arterial stiffness and is closely associated with an increase in the number of metabolic syndrome risk factors. Elevated abdominal obesity and low HDL-C are the main players affecting arterial stiffness in the middle-aged and elderly Chinese. These findings suggest that interaction of the individual components of metabolic syndrome plays a role in the relationship between metabolic syndrome and arterial stiffness.

  102. Methods for assessment of effects of habitual exercise on the autonomic nervous function using plethysmogram. Peer-reviewed

    Yoshizawa Makoto, Sugita Norihiro, Yambe Tomoyuki, Konno Satoshi, Sugai Telma Keiko, Abe Makoto, Homma Noriyasu

    Conf Proc IEEE Eng Med Biol Soc 2011 1157-1160 2011/04

    DOI: 10.1109/IEMBS.2011.6090271  

  103. Palpation nonlinear reaction force analysis for characterization of breast tissues. Peer-reviewed

    Kobayashi Yo, Tsukune Mariko, Hoshi Takeharu, Miyashita Tomoyuki, Shiraishi Yasuyuki, Yambe Tomoyuki, Fujie Masakatsu G

    Conf Proc IEEE Eng Med Biol Soc 2011 7393-7396 2011/04

    DOI: 10.1109/IEMBS.2011.6091721  

  104. 人工臓器医工学を用いた胃内拡張カプセルによる自律神経系を介した食欲抑制システム Peer-reviewed

    山家智之, 白石泰之, 三浦英和

    自律神経 48 (2) 146-146 2011/04

  105. Numerical Analysis of Effects of Measurement Errors on Ultrasonic-Measurement-Integrated Simulation Peer-reviewed

    Kenichi Funamoto, Toshiyuki Hayase, Yoshifumi Saijo, Tomoyuki Yambe

    IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING 58 (3) 653-663 2011/03

    Publisher: IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

    DOI: 10.1109/TBME.2010.2095418  

    ISSN:0018-9294

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    Ultrasonic-measurement-integrated (UMI) simulation, in which feedback signals are applied to the governing equations based on errors between ultrasonic measurement and numerical simulation, has been investigated for reproduction of the blood flow field. However, ultrasonic measurement data inherently include some errors. In this study, the effects of four major measurement errors, namely, errors due to Gaussian noise, aliasing, wall filter, and lack of data, on UMI simulation were examined by a numerical experiment dealing with the blood flow field in the descending aorta with an aneurysm, the same as in our previous study. While solving the governing equations in UMI simulation, Gaussian noise did not prevent the UMI simulation from effectively reproducing the blood flow field. In contrast, aliasing caused significant errors in UMI simulation. Effects of wall filter and lack of data appeared in diastole and in the whole period, respectively. By detecting significantly large feedback signals as a sign of aliasing and by not adding feedback signals where measured Doppler velocities were aliasing or zero, the computational accuracy substantially improved, alleviating the effects of measurement errors. Through these considerations, UMI simulation can provide accurate and detailed information on hemodynamics with suppression of four major measurement errors.

  106. 右房右室内に巨大血栓を有した肺塞栓症の一例 Peer-reviewed

    田渕晴名, 河部周子, 山口済, 山家実, 山中多聞, 中野陽夫, 菅原重生, 片平美明, 西條芳文, 山家智之

    超音波医学 38 (1) 33-33 2011/01

    Publisher: None

    ISSN:1346-1176

    eISSN:1881-9311

  107. 重回帰分析を用いた致死性不整脈検出アルゴリズムに関する検討 Peer-reviewed

    阿部誠, テルマ・ケイコ・スガイ, 吉澤誠, 山家智之, 清水一夫, 後藤萌, 稲垣正司, 杉町勝, 砂川賢二

    生体医工学 48 (6) 577-582 2010/12

    Publisher: Japanese Society for Medical and Biological Engineering

    DOI: 10.11239/jsmbe.48.577  

    ISSN:1347-443X

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    The implantable cardioverter-defibrillator (ICD) is an effective therapeutic device for rescuing patients with cardiac diseases from death caused by life-threatening arrhythmias. For development of the ICD, it is important to accurately distinguish among normal sinus rhythm, ventricular tachycardia (VT), ventricular fibrillation, and supraventricular tachycardia (SVT) . Thus, in this study, we have proposed a multiple regression model based on 14 indices extracted from two-dimensional statistics of intracardiac electrocardiograms to detect four kinds of cardiac rhythms as accurately and quickly as possible. The experimental results showed that the proposed method had a sensitivity of 0.97 for detecting SVT and a specificity of 0.99 for detecting VT, which were improved respectively from 0.83 and 0.85 obtained from the previous method, and that early detection within about 1.6 seconds was attained.

  108. 【シミュレータを用いた医療機器・治療法の安全性と有効性評価の現状と展望】 循環シミュレータによる右心系心臓代用弁の血行動態評価 Peer-reviewed

    白石泰之, 鈴木一郎, 梅津光生, 山岸正明, 山家智之

    人工臓器 39 (3) 214-217 2010/12

    Publisher: None

    DOI: 10.11392/jsao.39.214  

    ISSN:0300-0818

  109. ARTERIAL STIFFNESS IN CZECH POPULATION MEASURED BY VASERA 1500 Peer-reviewed

    DOBSAK PSOSIKOVA MDUSEK, LSOUCEK, MNOVAKOVA MYAMBE TWOLF, J.-EVITOVEC JSPINAROVA LSOSKA VFISER, BSIEGELOVA J

    SCRIPTA MEDICA 83 (2) 85-91 2010/11

  110. 電子診療鞄の展開と評価 Peer-reviewed

    杉田典大, 吉澤誠, 山家智之, 西條芳文, 金野敏, 仁田新一

    日本遠隔医療学会雑誌 6 (2) 207-210 2010/09

  111. 下側壁誘導の早期再分極と右室流出路型心室性期外収縮の経過観察中に突然死をきたした一例 Peer-reviewed

    山科順裕, 八木哲夫, 滑川明男, 石田明彦, 佐藤弘和, 中川孝, 桜本万治郎, 佐藤英二, 菊地次郎, 山家智之

    仙台市立病院医学雑誌 30 71-74 2010/08

  112. 形状記憶合金を用いた人工食道アクチュエータの蠕動運動特性評価 Peer-reviewed

    三木寛之, 奥山武志, 小平真吾, 羅雲, 高木敏行, 山家智之

    日本機械学会論文集 1560-1566 2010/07

    DOI: 10.1299/kikaic.76.1560  

  113. Brief Effect of Acupuncture on the Peripheral Arterial System of the Upper Limb and Systemic Hemodynamics in Humans Peer-reviewed

    Shin Takayama, Takashi Seki, Masashi Watanabe, Yasutake Monma, San Yue Yang, Norihiro Sugita, Satoshi Konno, Yoshifumi Saijo, Tomoyuki Yambe, Nobuo Yaegashi, Makoto Yoshizawa, Shin-ichi Nitta

    JOURNAL OF ALTERNATIVE AND COMPLEMENTARY MEDICINE 16 (7) 707-713 2010/07

    Publisher: MARY ANN LIEBERT, INC

    DOI: 10.1089/acm.2009.0355  

    ISSN:1075-5535

    eISSN:1557-7708

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    Background: Pulse diagnosis of the peripheral artery is an important technique in Traditional Chinese Medicine, where, in acupuncture therapy, the treatment is adjusted according to the observed changes of the pulse. We investigated the change of blood flow in the peripheral artery and the cardiac index during acupuncture treatment. Objectives: The aim of this study is to explore the effect of acupuncture on radial and brachial artery blood flow volume and the cardiac index in healthy subjects. Methods: Eighteen (18) healthy volunteers were enrolled. Acupuncture was performed bilaterally on LR-3 with manual rotation of the needles. The blood pressure and heart rate were measured at rest and 180 seconds after acupuncture. Radial and brachial artery blood flow volume was monitored continuously by an ultrasound with an echo-tracking system. Cardiac index was measured by impedance cardiography. The hemodynamic parameters were measured before, during, and 30, 60, 180 seconds after acupuncture. Results: The peripheral artery blood flow volume decreased significantly during acupuncture (radial; p&lt;0.01, brachial; p&lt;0.05) but increased at 180 seconds after acupuncture (radial; p&lt;0.05, brachial; p&lt;0.05) compared with before acupuncture. The cardiac index did not change significantly after acupuncture, but systemic vascular resistance index significantly decreased (p&lt;0.05). Conclusions: The present study showed that radial and brachial artery blood flow volume decreased immediately during acupuncture on LR-3 acupoint, but increased at 180 seconds after acupuncture. This reaction is attributed to the change in peripheral vascular resistance.

  114. Oxygenation to Bovine Blood in Artificial Heart and Lung Using Vibrating, Flow Pump Peer-reviewed

    Hirofumi Shintaku, Tsubasa Yonemura, Kazuaki Tsuru, Takashi Isoyama, Tomoyuki Yambe, Satoyuki Kawano

    Experiment and Numerical Analysis Based on Non-Newtonian Model Journal of Fluid Science and Technology 5 (2) 292-304 2010/06

    Publisher: The Japan Society of Mechanical Engineers

    DOI: 10.1299/jfst.5.292  

    ISSN:1880-5558

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    In this study, we construct an experimental apparatus for a prototype artificial heart and lung (AHL) by installing hollow fibers into the cylindrical tube of the vibrating flow pump (VFP). The oxygenation characteristics are investigated both by experiments using bovine blood and by numerical analyses based on the computational fluid dynamics. The analyses are carried out at the Reynolds numbers <I>Re</I> ranged from <I>O</I>(1) to <I>O</I>(10<SUP>3</SUP>), which are determined based on the experimental conditions. The blood flow and the diffusion of oxygen gas are analyzed based on the Newtonian/non-Newtonian, unsteady, incompressible and axisymmetric Navier-Stokes equations, and the advection-diffusion equation. The results show that the oxygenation rate increases in proportion to <I>Re</I><SUP>1/3</SUP>, where the phenomenon corresponds to the decreasing thickness of the concentration boundary layer with <I>Re</I>. Although the effects of the vibrating flow and the rheology of the blood are clearly appeared on the velocity field, their effects on the gas exchange are relatively small at the ranges of prescribed Reynolds numbers. Furthermore, the numerical results in terms of the oxygenation rate are compared with the experimental ones. The basic design data of VFP were accumulated for the development of AHL in the clinical applications.

  115. Efficacy of bundle ablation for cavotricuspid isthmus-dependent atrial flutter: combination of the maximum voltage-guided ablation technique and high-density electro-anatomical mapping Peer-reviewed

    Hirokazu Sato, Tetsuo Yagi, Akio Namekawa, Akihiko Ishida, Yoshihiro Yamashina, Takashi Nakagawa, Manjirou Sakuramoto, Eiji Sato, Tomoyuki Yambe

    JOURNAL OF INTERVENTIONAL CARDIAC ELECTROPHYSIOLOGY 28 (1) 39-44 2010/06

    Publisher: SPRINGER

    DOI: 10.1007/s10840-010-9468-6  

    ISSN:1383-875X

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    Pathological studies have demonstrated that the cavotricuspid isthmus (CTI) is often composed of discrete muscle bundles, which are thought to be represented electrically as high-amplitude electrograms. Based on this observation, we visualized the bundles using an electro-anatomical mapping system (EAMS) and investigate the efficacy of bundle ablation which is an ablation method for selectively targeting high-voltage sites obtained by high-density electro-anatomical mapping along the CTI. Sixty patients with atrial flutter were randomly assigned to cavotricuspid isthmus ablation using a conventional anatomical approach (Group 1) or bundle ablation approach (Group 2). In Group 2, CTI was mapped in detail with EAMS, and we visualized the bundles that were 1.5 mV or more on a bipolar voltage map. Radiofrequency (RF) ablation was delivered sequentially from the maximum voltage site at the shortest distance of the bundle until bidirectional block was achieved. Bidirectional block was achieved in all patients. Mean ablation times (Group 1, 1,392 +/- 960 s; Group 2, 638 +/- 342 s, p &lt; 0.01), the mean number of RF applications (Group 1, 31.7 +/- 23.6; Group 2, 13.0 +/- 7.0, p &lt; 0.01), and fluoroscopy times (Group 1, 50.4 +/- 28.3 min; Group 2, 42.3 +/- 21.3 min, p &lt; 0.01) were significantly shorter in Group 2 than those in Group 1. Bundle ablation at CTI is highly effective for achieving a bidirectional block requiring shorter ablation times, shorter fluoroscopy times, and fewer RF applications.

  116. ナノテクノロジーを応用したテーラーメイド人工心筋 Peer-reviewed

    山家智之, 白石泰之, 三浦英和, 馬場敦, 井街宏, 早瀬敏幸, 円山重直, 柴田宗一, 三引義明, 大沢上, 佐藤尚

    東北医学雑誌 122 (1) 65-70 2010/06

  117. Estimation of Maximum Ventricular Elastance Under Assistance With a Rotary Blood Pump Peer-reviewed

    Telma K. Sugai, Akira Tanaka, Makoto Yoshizawa, Yasuyuki Shiraishi, Tomoyuki Yambe, Shin-ichi Nitta, Atsushi Baba

    ARTIFICIAL ORGANS 34 (5) 442-446 2010/05

    Publisher: WILEY-BLACKWELL

    DOI: 10.1111/j.1525-1594.2009.00876.x  

    ISSN:0160-564X

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    The maximum ventricular elastance is a reliable index for assessing the cardiac function from changes in its pressure-volume relationship. The advantage of this index is that it can represent the contractility of either unassisted hearts or native hearts assisted with rotary blood pumps. However, there are situations in which changes in the ventricular load required for the conventional estimation method might be risky. For example, in a bridge-to-recovery the cardiac function should also be continuously observed after the implantation of a rotary blood pump. In this article, we present the results of the estimation of the maximum elastance with in vivo data using the parameter optimization method, which is a single-beat estimation method. The estimated values for the normal cardiac function (6.8 +/- 0.6, 4.5 +/- 0.9, 4.2 +/- 1.8 mm Hg/mL) were significantly different from those for the low cardiac function (3.2 +/- 1.5, 1.9 +/- 1.0, 1.9 +/- 1.2 mm Hg/mL) from the data of the three animals that were analyzed. Besides, the maximum elastance values were independent of the pump rotational speed. These results indicate that this index might be useful for the detection of the myocardial recovery.

  118. 【循環制御の基礎の進歩】 循環制御機能をコントロールすることができる乗用車の可能性の展開 Peer-reviewed

    山家智之, 金野敏, 白石泰之, 劉紅煎, 川島隆太, 阿部恒之, 杉田典大, 吉沢誠, 関隆志

    循環制御 30 (3) 127-141 2010/05

  119. A-V-V-Aパターンでのみ誘発されたnarrow QRS tachycardiaの1例

    田渕 晴名, 山中 多聞, 河部 周子, 山口 済, 山家 実, 中野 陽夫, 菅原 重生, 片平 美明, 西條 芳文, 山家 智之

    Journal of Arrhythmia 26 (Suppl.) 279-279 2010/04

    Publisher: (一社)日本不整脈心電学会

    ISSN:1880-4276

    eISSN:1883-2148

  120. Influence of rotary blood pumps over preload recruitable stroke work. Peer-reviewed

    Sugai Telma Keiko, Tanaka Akira, Yoshizawa Makoto, Shiraishi Yasuyuki, Baba Atsushi, Yambe Tomoyuki, Nitta Shin-Ichi

    Conf Proc IEEE Eng Med Biol Soc 2010 2367-2370 2010/04

    DOI: 10.1109/IEMBS.2010.5627916  

  121. Dynamic characteristics between the subjective score of motion sickness discomfort and video global motion. Peer-reviewed

    Tanaka Akira, Sugita Norihiro, Yoshizawa Makoto, Abe Makoto, Yambe Tomoyuki

    Conf Proc IEEE Eng Med Biol Soc 2010 1368-1369 2010/04

    DOI: 10.1109/IEMBS.2010.5626739  

  122. A mobile communications system for home-visit medical services: the Electronic Doctor's Bag. Peer-reviewed

    Yoshizawa Makoto, Yambe Tomoyuki, Konno Satoshi, Saijo Yoshifumi, Sugita Norihiro, Sugai Telma Keiko, Abe Makoto, Sonobe Taro, Katahira Yoshiaki, Nitta Shin-Ichi

    Conf Proc IEEE Eng Med Biol Soc 2010 5496-5499 2010/04

    DOI: 10.1109/IEMBS.2010.5626577  

  123. RADIAL ARTERY HEMODYNAMIC CHANGES RELATED TO ACUPUNCTURE Peer-reviewed

    Shin Takayama, Takashi Seki, Norihiro Sugita, Satoshi Konno, Hiroyuki Arai, Yoshifumi Saijo, Tomoyuki Yambe, Nobuo Yaegashi, Makoto Yoshizawa, Shin-ichi Nitta

    EXPLORE-THE JOURNAL OF SCIENCE AND HEALING 6 (2) 100-105 2010/03

    Publisher: ELSEVIER SCIENCE INC

    DOI: 10.1016/j.explore.2009.12.001  

    ISSN:1550-8307

    eISSN:1878-7541

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    Background: Assessment of the radial pulse by palpation (pulse diagnosis) is an important diagnostic technique in Traditional Chinese Medicine (TCM), but the changes of blood flow volume in the radial artery during and after acupuncture are unknown. Objective: The aim of this study was to explore the changes of radial artery blood flow volume during and after acupuncture in healthy subjects. Design: This study was conducted as a pilot study utilizing a one-group intervention design. Setting: The study was conducted at a TCM outpatient clinic of Tohoku University Hospital. Participants: Twenty-six healthy volunteers participated in the study. Intervention: Acupuncture was performed at LR-3 bilaterally with manual rotation of the needles. Outcome Measures: Blood pressure was measured at rest and 180 seconds after acupuncture. Radial artery hemodynamics were monitored continuously with a high-resolution ultrasound echo-tracking system. The vessel diameter and blood flow volume of the right radial artery and heart rate were measured at rest, before acupuncture, during acupuncture, and 30, 60, and 180 seconds after acupuncture. Results: The systolic and diastolic diameter of the radial artery did not significantly change. Radial artery blood flow volume decreased significantly during acupuncture (mean +/- SD, 0.16 +/- 0.11 mL/sec per m(2); P &lt; .01) compared with baseline (0.43 +/- 0.27 mL/sec per m(2)), but was increased at 180 seconds after acupuncture (0.54 +/- 0.28 mL/sec per m(2); P &lt; .01). Conclusions: The present study showed that radial artery blood flow volume decreased immediately during acupuncture at the LR-3 acupoint, but was increased at 180 seconds after acupuncture.

  124. Clinical and Electrophysiological Difference Between Idiopathic Right Ventricular Outflow Tract Arrhythmias and Pulmonary Artery Arrhythmias Peer-reviewed

    Yoshihiro Yamashina, Tetsuo Yagi, Akio Namekawa, Akihiko Ishida, Hirokazu Sato, Takashi Nakagawa, Manjirou Sakuramoto, Eiji Sato, Tomoyuki Yambe

    JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY 21 (2) 163-169 2010/02

    Publisher: WILEY-BLACKWELL PUBLISHING, INC

    DOI: 10.1111/j.1540-8167.2009.01601.x  

    ISSN:1045-3873

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    Characteristics of Pulmonary Artery Arrhythmias. Introduction: The precise incidence and characteristics of ventricular arrhythmias originating from the pulmonary artery have not been fully described. The purpose of this prospective study was to clarify these points. Methods: Thirty-three consecutive patients with an idiopathic left bundle branch block and inferior-axis deviation type ventricular arrhythmia were included. All patients underwent detailed electroanatomical mapping (CARTO, Biosense-Webster, Diamond Bar, CA, USA) during sinus rhythm prior to the catheter ablation. The precise location of the catheter tip at the successful ablation site was confirmed by both electroanatomical mapping and contrast radiography. The clinical and electrophysiological data were compared between the right ventricular outflow tract (RVOT) arrhythmia patients (RVOT group) and PA arrhythmia patients (PA group). Results: Eight patients (8/33 patients: 24.2%) had their ventricular arrhythmias successfully ablated within the PA. The local bipolar electrogram at the successful ablation sites in the PA group exhibited a significantly greater duration (P &lt; 0.05) and lower amplitude (P &lt; 0.05) than did those in the RVOT group (n = 19). In the PA group, all patients exhibited a multicomponent electrograms composed of a spiky potential and a dull potential, which might have consisted of near-field PA activation and a far-field ventricular activation, respectively, at the successful ablation site. Direct ablation to the spiky electrogram was able to eliminate the arrhythmias in all the PA group patients. Conclusions: PA arrhythmias may be more common than previously recognized. Careful mapping and interpretation of low amplitude and multicomponent electrograms are important for recognizing ventricular arrhythmias originating from the PA. (J Cardiovasc Electrophysiol, Vol. 21, pp. 163-169, February 2010).

  125. 診断治療機能を保持する自動車の可能性 Peer-reviewed

    山家智之, 金野敏, 白石泰之, 川島隆太, 阿部恒之, 杉田典大, 吉沢誠, 関隆志

    日本臨床生理学会雑誌 40 (1) 5-14 2010/02

  126. Effect of measurement error on ultrasonic-measurement-integrated simulation of blood flow in an aortic aneurysm Peer-reviewed

    K. Funamoto, T. Hayase, Y. Saijo, T. Yambe

    IFMBE Proceedings 31 1652-1655 2010

    DOI: 10.1007/978-3-642-14515-5_420  

    ISSN:1680-0737

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    Stresses due to blood flow on a blood vessel wall (hemodynamic stresses) are closely related to development and progression of circulatory diseases such as atherosclerosis and aneurysm. Therefore, for advanced diagnosis of circulatory diseases, accurate and detailed information of hemodynamics is necessary. To reproduce blood flow field, we have proposed ultrasonic- measurement-integrated (UMI) simulation, in which feedback signals are applied to the governing equations based on errors between ultrasonic measurement and numerical simulation at feedback points. Efficiency of the UMI simulation was shown by our previous numerical experiment dealing with a three-dimensional unsteady blood flow field in the descending aorta with an aneurysm. However, real ultrasonic measurement data inherently includes some errors. In this study, the effects of four major measurement errors, namely, errors due to Gaussian noise, aliasing, wall filter and lack of data, on computational accuracy of the UMI simulation were examined by a numerical experiment dealing with the blood flow field in an aortic aneurysm, the same as in our previous study. While solving the governing equations in UMI simulation, Gaussian noise did not work as an effective feedback signal, and, therefore, hardly influenced the computational result. In contrast, aliasing caused significant errors in the UMI simulation. By detecting significantly large feedback signals as a sign of aliasing and by replacing the measured Doppler velocity with the computational one, the computational accuracy of the UMI simulation was substantially improved. Effects of wall filter and lack of data especially appeared in diastole and in systole, respectively, but they were alleviated by not adding feedback signals where measured Doppler velocities were zero. Hence, UMI simulation can be performed with suppression of measurement errors. © 2010 International Federation for Medical and Biological Engineering.

  127. Tangible Modelling of Ventricular Aneurysm Peer-reviewed

    Y. Shiraishi, S. Yabe, H. Lin, T. K. Sugai, Y. Saijo, T. Fujimoto, M. Umezu, T. Yambe, Y. Saiki, K. Tabayashi

    6TH WORLD CONGRESS OF BIOMECHANICS (WCB 2010), PTS 1-3 31 469-+ 2010

    Publisher: SPRINGER

    ISSN:1680-0737

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    Myocardial infarction (MI) may cause left ventricular aneurysms (LVAs) as the long-term and obsolete complications. Following MI, the scar will replace the necrotic lesion within a few weeks. As a result, a portion of the left ventricular free wall protrudes, which leads to appearance of LVAs. The three dimensional echocardiography, the computed tomography and the magnetic resonance imaging (MRI) are the most effective tools to diagnose the left ventricular volumetric function and its wall motion. And the primary choice to treat LVAs is surgical therapy, which is called the left ventricular reconstructive surgery (LVRS). The LVRS such as Dor procedure is performed to resume the left ventricular shape and its original myocardial fibre orientation as much as possible. Furthermore, we also have to consider the location of the couple of papillary muscle in order to maintain the mitral valvular functions. When the ventricle dilates due to the obsolete MI, the papillary muscles might be displaced away from the mitral valvular annulus, leading to decreased coaptaion of the mitral leaflets and mitral regurgitation. As the clinical status, the surgeons establish the surgical planning of LVRS according to their design, evidence and experience base on the diagnostic imaging, which is difficult to estimate the postoperative cardiac function and structure quantitatively. The purpose of this study was to support surgeons to examine more quantitative surgical strategies by dint of engineering approach as fabrication of diseased ventricular tangible elastic model and numerical analyses in each patient prior to the treatment. Then we developed a prototyping method of fabrication for elastic ventricular models by the normal sequence of MRI data, which could show the identical and quantitative representation of diagnostic imaging. It is anticipated that these methods could realise the quantitative images and expressions as well as the intercommunity to the strategy of surgical therapy to reduce the patients' risk. As the results: a) An engineering method for the three-dimension reconstruction of diseased ventricular configuration from MRI in cardiac end-systole and end-diastole was established. By using of this method, the evaluation of ventricular motive displacement could be realized and farther researches could be performed base on the reconstructed data. b) A distinctive short-term process for fabricating tangible elastic diseased ventricular model was established. The models could give the surgeons a tangible image of the diseased ventricular shape. On the other hand, preoperative investigations of ventricular blood volume and morphological characteristic could be accomplished. c) The presentation of ventricular wall stress distribution around the diseased lesion was simulated by the finite element method (FEM). According to the result of numerical analyses, it was indicated that the stress distribution was greatly related with the ventricular shape. Moreover, the boundary between the diseased lesion and normal portion, which is important for the decision of surgical position, was shown distinctly.

  128. 人工心筋と生体の適応 Peer-reviewed

    白石泰之, 金子芳一, 金野敏, 劉紅箭, 山家智之, 佐藤優太, 馬場敦, 藤本哲男, 梅津光生, 本間大

    適応医学 13 (2) 2-8 2010/01

  129. 各種疾患 自律神経疾患 人工血圧反射 Peer-reviewed

    山家智之, 三浦英和, 白石泰之, 吉澤誠, 田中明

    Annual Review神経 2010 259-266 2010/01

  130. The Effect of Warming of the Abdomen and of Herbal Medicine on Superior Mesenteric Artery Blood Flow - a Pilot Study Peer-reviewed

    Shin Takayama, Takashi Seki, Masashi Watanabe, Shigeru Takashima, Norihiro Sugita, Satoshi Konno, Koh Iwasaki, Tomoyuki Yambe, Makoto Yoshizawa, Shin-ichi Nitta, Shigenao Maruyama, Nobuo Yaegashi

    FORSCHENDE KOMPLEMENTARMEDIZIN 17 (4) 195-201 2010

    Publisher: KARGER

    DOI: 10.1159/000317845  

    ISSN:1661-4119

    eISSN:1661-4127

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    Background: In traditional Japanese and Chinese medicine, warming the abdomen with moxibustion or herbal medicines has been used for various diseases. However, the effects of these therapies on hemodynamics have not been clear. We clarify the physiological effects of these therapies on the superior mesenteric artery (SMA) blood flow. Participants and Methods: 28 healthy male volunteers were randomly assigned to groups A and B. Group A (n = 14) underwent local thermal stimulation of the paraumbilical region for 20 min at a temperature of 40 degrees C; this simulated the heat and mechanical pressure effects of moxibustion. Group B (n = 14) took the herbal medicine Daikenchuto (TJ-100; 5.0 g) with distilled water. As a control, group C (n = 14) took distilled water alone. Blood flow volume in the SMA was measured by ultrasound from rest to 50 min after the start of each intervention. Results: The SMA blood flow volume increased significantly between 10 to 40 min after the start of thermal stimulation (p &lt; 0.05), and it also increased significantly between 10 to 50 min after administration of TJ-100 (p &lt; 0.01) as compared to the resting volume. However, SMA blood flow volume did not change significantly after administration of water alone. There was no significant difference in SMA blood flow changes between groups A and B. Conclusions: The results suggest that one of the physiological effects of warming the abdomen according to a traditional concept in thermal stimulation and herbal medicine is an increase of SMA blood flow volume.

  131. The Herbal Medicine Daikenchuto Increases Blood Flow in the Superior Mesenteric Artery Peer-reviewed

    Shin Takayama, Takashi Seki, Masashi Watanabe, Yasutake Monma, Norihiro Sugita, Satoshi Konno, Koh Iwasaki, Takashi Takeda, Tomoyuki Yambe, Makoto Yoshizawa, Shin-ichi Nitta, Nobuo Yaegashi

    TOHOKU JOURNAL OF EXPERIMENTAL MEDICINE 219 (4) 319-330 2009/12

    Publisher: TOHOKU UNIV MEDICAL PRESS

    DOI: 10.1620/tjem.219.319  

    ISSN:0040-8727

    eISSN:1349-3329

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    Daikenchuto is a traditional herbal medicine that is used for the treatment of cold feeling in the abdomen, while Orengedokuto, also a traditional herbal medicine, is used for treating inflammatory and ulcerative diseases affecting internal organs. However, the effects of these herbal medicines on cardiac output (CO) and intestinal blood flow have never been investigated. This examiner-blinded randomized crossover study intended to clarify the influence of Daikenchuto and Orengedokuto on CO and blood flow volume in the superior mesenteric artery (SMA). Fourteen healthy men (35 +/- 7 years old) were randomly assigned to two groups: group A and group B. Initially, all subjects were given 50 ml of water orally. After 7 days, subjects in group A were given 5.0 g of Daikenchuto, and 7 days later they were given 2.5 g of Orengedokuto. These herbal medicines were given to group B subjects in the reverse order. CO and SMA blood flow volume were measured from rest to 90 min after the administration of water or each medicine. There was a significant increase in SMA blood flow volume after the administration of Daikenchuto, compared to water alone (p &lt; 0.05) and Orengedokuto (p &lt; 0.05). SMA blood flow volume was significantly increased between 5 and 90 min after administration of Daikenchuto (p &lt; 0.01) compared to the resting state. However, there was no significant change in CO after the administration of either agent. The present study indicates that Daikenchuto increases SMA blood flow volume without increasing CO.

  132. Brain mapping method utilizing rapid coolong probe Peer-reviewed

    Takeda Hiroshi Maruyama Shigenao, Yambe Tomoyuki, Nakasato Hidekazu, Komiya Atshuki

    I.J.Trans.Phenomena 11 147-163 2009/11

  133. 高精度温度制御加熱装置による温熱治療とその評価 Peer-reviewed

    円山重直, 高島茂, 小宮敦樹, 関隆志, 山家智之

    日本機械学会論文集 75 167-171 2009/10

    DOI: 10.1299/kikaib.75.758_2055  

  134. Baroreflex Sensitivity of an Arterial Wall During Rotary Blood Pump Assistance Peer-reviewed

    Tomoyuki Yambe, Kou Imachi, Yasuyuki Shiraishi, Tasuku Yamaguchi, Mune-ichi Shibata, Takeshi Kameyama, Makoto Yoshizawa, Norihiro Sugita

    ARTIFICIAL ORGANS 33 (9) 767-769 2009/09

    Publisher: WILEY-BLACKWELL

    DOI: 10.1111/j.1525-1594.2009.00864.x  

    ISSN:0160-564X

    eISSN:1525-1594

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    It is well known that the baroreflex system is one of the most important indicators of the pathophysiology in hypertensive patients. We can check the sensitivity of the baroreflex by observing heart rate (HR) responses; however, there is no simple diagnostic method to measure the arterial behavior in the baroreflex system. Presently, we report the development of a method and associated hardware that enables the diagnosis of baroreflex sensitivity by measuring the responses of both the heart and the artery. In this system, the measurements are obtained by monitoring an electrocardiogram and a pulse wave recorded from the radial artery or fingertip. The arterial responses were measured in terms of the pulse wave velocity (PWV) calculated from the pulse wave transmission time (PTT) from the heart to the artery. In this system, the HR change corresponding to the blood pressure change in time series sequence was observed. Slope of the changes in blood pressure and HR indicated the sensitivity of the baroreflex system of the heart. This system could also measure the sensitivity of the baroreflex system of an artery. Changes in the PWV in response to the blood pressure changes were observed. Significant correlation was observed in the time sequence between blood pressure change and PWV change after calculating the delay time by cross-correlation. The slope of these parameter changes was easily obtained and it demonstrated the sensitivity of the baroreflex system of an artery. We evaluated this method in animal experiments using rotary blood pump (RBP) with undulation pump ventricular assist device, and PTT elongation was observed in response to increased blood pressure with RBP assistance. Furthermore, when tested clinically, decreased sensitivity of the baroreflex system in hypertensive patients was observed. This system may be useful when we consider the ideal treatment and follow-up of patients with hypertension.

  135. Hemodynamic response with an artificial myocardial assistance in chronic animal, examination Peer-reviewed

    Y. Shiraishi, T. Yambe, Y. Saijo, M. Shibata, H. Liu, T. Sugai, A. Tanaka, S. Konno, A. Baba T, Fujimoto K, Imachi M. Yoshizawa, S. Nitta, H. Sasada, K. Tabayashi, Y. Sato, M, Umezu D, Hom

    WC 2009, IFMBE Proceedings 25 (8) 277-280 2009/09

    DOI: 10.1007/978-3-642-03887-7-80  

  136. Deveropment of an Artificial Internal Organs and the New Diagnosis Tool of Pulse Wave Peer-reviewed

    Tomoyuki Yambe

    Tohoku University Global COE Programme 2 181-191 2009/09

  137. Chronic Trial of an Artificial Myocardium in Goats and Preliminary Modelling of Diseased Heart Peer-reviewed

    Yasuyuki Shiraishi, Tomoyuki YambeSatoshi KonnoYoshihumi SaijoMuneichi ShibataHongjian LiuHiroshi, SasadaKoichi TabayashiTelma Keiko SugaiAtsushi BabaMakoto YoshizawaMitsuo UmezuTetsuko FujimotoAkira, TanakaDai Homma

    Tohoku University Global COE Programme 2 213-221 2009/09

  138. Deveropment of a Quantitative Method for Assessment of Integrated Medicine Peer-reviewed

    Makoto YoshizawaTakashi Seki, Norihito SugitaMakoto, AbeAkira TanakaSatoshi Konno, Hiroshi KawataTomoyuki Yambe, Shin-ichi Nitta

    Tohoku University Global COE Programme 2 47-54 2009/08

  139. Analysis of Baroreflex Sensitivity During Undulation Pump Ventricular Assist Device Support Peer-reviewed

    Hongjian Liu, Yasuyuki Shiraishi, Xiumin Zhang, Hojin Song, Yoshifumi Saijo, Atsushi Baba, Tomoyuki Yambe, Yusuke Abe, Kou Imachi

    ARTIFICIAL ORGANS 33 (7) 561-564 2009/07

    Publisher: WILEY-BLACKWELL PUBLISHING, INC

    DOI: 10.1111/j.1525-1594.2009.00738.x  

    ISSN:0160-564X

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    The aim of this study was to examine the baroreflex sensitivity (BRS), which involves the autonomic nervous system, in a goat with a chronically implanted undulation pump ventricular assist device (UPVAD). The UPVAD involved transforming the rotation of a brushless DC motor into an undulating motion by a disc attached via a special linking mechanism, and a jellyfish valve in the outflow cannula to prevent diastolic backflow. The pump was implanted into the thoracic cavity of a goat by a left thoracotomy, and the inflow and outflow cannulae were sutured to the apex of the left ventricle and to the descending aorta, respectively. The driving cable was wired percutaneously to an external controller. Electrocardiogram and hemodynamic waveforms were recorded at a sampling frequency of 1 kHz. BRS was determined when awake by the slope of the linear regression of R-R interval against mean arterial pressure changes, which were induced by the administration of methoxamine hydrochloride, both with continuous driving of the UPVAD as well as without assistance. BRS values during the UPVAD support and without assistance were 1.60 +/- 0.30 msec/mm Hg and 0.98 +/- 0.22 msec/mm Hg (n = 5, P &lt; 0.05), respectively. BRS was significantly improved during left ventricular assistance. Therefore, UPVAD support might decrease sympathetic nerve activity and increase parasympathetic nerve activity to improve both microcirculation and organ function.

  140. Brain Activation Associated With Changes in Heart Rate, Heart Rate Variability, and Plasma Catecholamines During Rectal Distention Peer-reviewed

    Hideaki Suzuki, Satoshi Watanabe, Toyohiro Hamaguchi, Hirotaka Mine, Takahiro Terui, Motoyori Kanazawa, Noriko Oohisa, Mitsuya Maruyama, Tomoyuki Yambe, Masatoshi Itoh, Shin Fukudo

    PSYCHOSOMATIC MEDICINE 71 (6) 619-626 2009/07

    Publisher: LIPPINCOTT WILLIAMS & WILKINS

    DOI: 10.1097/PSY.0b013e31819b69ca  

    ISSN:0033-3174

    eISSN:1534-7796

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    Objective: To test the hypothesis that gut stimulation provokes autonomic arousal via activation of regional cerebral cortices. How the human brain processes interoceptive signals and forms initial autonomic arousal is one of the key questions to be answered in research on emotion. Methods: Twelve healthy males participated in this study. A barostat bag was inserted in the rectum and intermittently inflated with 0, 20, or 40 mm Hg at random for 80 seconds. (H2O)-O-15 positron emission tomography (PET) of the brain, electrocardiography, and blood sampling for catecholamines were performed. Changes in regional cerebral blood flow were interpreted using statistical parametric mapping. Results: Rectal distention with 40 mm Hg induced a significant increase in heart rate, low frequency (LF)/high frequency (HF) ratio of heart rate variability, and plasma adrenaline. Activated brain areas that were associated with increased heart rate during rectal distention were the right insula, right operculum, right dorsolateral prefirontal cortex, putamen, thalamus, periaqueductal gray, and cerebellum (p &lt;.001, uncorrected), whereas those that were associated with an increased LF/HF ratio were the bilateral insula, putamen, thalamus, midbrain, pons, and cerebellum (p &lt;.001, uncorrected). Activated brain areas that were associated with increased plasma adrenaline were the right insula, right orbitofirontal cortex, right parahippocampal gyrus, putamen, thalamus, periaqueductal gray, pons, and cerebellum (p &lt;.001, uncorrected). Conclusion: Our results suggest that the right insula and the related body mapping regions may form the functional module of sympathetic arousal in response to gut stimulation.

  141. Distribution of Successful Ablation Sites of Idiopathic Right Ventricular Outflow Tract Tachycardia Peer-reviewed

    Yoshihiro Yamashina, Tetsuo Yagi, Akio Namekawa, Akihiko Ishida, Hirokazu Sato, Takashi Nakagawa, Manjirou Sakuramoto, Eiji Sato, Tomoyuki Yambe

    PACE-PACING AND CLINICAL ELECTROPHYSIOLOGY 32 (6) 727-733 2009/06

    Publisher: WILEY-BLACKWELL PUBLISHING, INC

    DOI: 10.1111/j.1540-8159.2009.02358.x  

    ISSN:0147-8389

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    Background: There are few studies evaluating the distribution of successful ablation sites of idiopathic right ventricular outflow tract (RVOT) arrhythmias using a three-dimensional electroanatomical mapping system. This study aims to clarify the favorite site of idiopathic RVOT arrhythmias through electroanatomical voltage mapping using the CARTO system (Biosense Webster, Diamond Bar, CA, USA). Methods: A consecutive series of 72 patients (mean age 43.6 +/- 16.2 years, 32 males) who underwent radiofrequency catheter ablation (RFCA) for a total of 82 morphologies of idiopathic RVOT arrhythmias were studied. Detailed three-dimensional electroanatomical voltage maps of the RVOT were obtained using the CARTO system prior to the RFCA during sinus rhythm. The voltage on bipolar electrogram was defined as follows: amplitude &lt; 0.5 mV as "low-voltage zone," amplitude between 0.5 and 1.5 mV as "transitional-voltage zone," and amplitude &gt; 1.5 mV as "high-voltage zone." Successful ablation sites were electroanatomically classified into each voltage zone. Results: Successful ablation was acquired in 63 patients and 71 RVOT arrhythmias (63/72 patients: 87.5%, 71/82 RVOT arrhythmias: 86.5%). In the successful group, three arrhythmias (4.2%) were classified in the low-voltage zone, 63 arrhythmias (88.7%) in the transitional-voltage zone, and five arrhythmias (7.0%) in the high-voltage zone. Conclusions: This study indicates that the vast majority of successful ablation sites for idiopathic RVOT arrhythmias are located in the transitional-voltage zone. Mapping of the transitional-voltage zone may be an important landmark of RFCA for RVOT arrhythmia. (PACE 2009; 32:727-733).

  142. Assessment of synchronization measures for effective ventricular support by using the shape memory alloy fibred artificial myocardium in goats. Peer-reviewed

    Shiraishi Y, Yambe T, Saijo Y, Sato F, Tanaka A, Yoshizawa M, Sugai T K, Kaneko Y, Sato Y, Uematsu M, Umezu M, Fujimoto T, Masumoto N, Liu H, Baba A, Konno S, Tabayashi K, Sasada H, Homma D

    Conf Proc IEEE Eng Med Biol Soc 2009 3047-3050 2009/04

    DOI: 10.1109/IEMBS.2009.5333627  

  143. Estimation of blood pressure variability using independent component analysis of photoplethysmographic signal. Peer-reviewed

    Abe Makoto, Yoshizawa Makoto, Sugita Norihiro, Tanaka Akira, Chiba Shigeru, Yambe Tomoyuki, Nitta Shin-ichi

    Conf Proc IEEE Eng Med Biol Soc 2009 348-351 2009/04

    DOI: 10.1109/IEMBS.2009.5333155  

  144. Development of new quantitative diagnosis machine to evaluate the baroreflex sensitivity of an artery for patients with hypertension. Peer-reviewed

    Yambe Tomoyuki, Sugita Norihiro, Yoshizawa Makoto

    Conf Proc IEEE Eng Med Biol Soc 2009 888-891 2009/04

    DOI: 10.1109/IEMBS.2009.5332644  

  145. Human histopathology of substrate based linear radiofrequency catheter ablation to electrical storm in old inferior myocardial infarction Peer-reviewed

    Yoshihiro Yamashina, Tetsuo Yagi, Akio Namekawa, Akihiko Ishida, Hirokazu Sato, Takashi Nakagawa, Manjirou Sakuramoto, Hiroshi Naganuma, Tomoyuki Yambe

    JOURNAL OF INTERVENTIONAL CARDIAC ELECTROPHYSIOLOGY 24 (2) 139-142 2009/03

    Publisher: SPRINGER

    DOI: 10.1007/s10840-008-9313-3  

    ISSN:1383-875X

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    A 62-year-old-male with old inferior myocardial infarction suffered from drug resistant electrical storms and frequent shocks from an implantable cardioverter defibrillator. Emergent radiofrequency catheter ablation was performed. The patient underwent substrate mapping that uses an electro-anatomical mapping system during sinus rhythm because of multiple QRS morphologies and hemodynamic instability during ventricle tachycardia. The electro-anatomical map revealed a massive low voltage zone (&lt; 0.4 mV on amplitude of bipolar voltages) in the inferior wall of the left ventricle. Several ablation lines were placed (1) around the low voltage zone and (2) traversing the low voltage zone. After the ablation, electrical storms were well suppressed. Three weeks later he died due to pneumonia. Postmortal evaluation specified sites in the low voltage zone on invital electro-anatomical mapping were well correlated to histopathological dense scar. The ablation produced coagulation necrosis up to a maximum depth of 4.2 mm.

  146. Brain Mapping Method Utilizing Rapid Cooling Probe Peer-reviewed

    H Takeda, S, Maruyama T, Yambe N Nakasato

    I.J. Trans. Phenomena 11 147-163 2009/03

  147. Artificial-esophagus with Peristaltic Motion using Shape Memory Alloy Peer-reviewed

    Hiroyuki Miki, Toshiyulci Takagi, Takeshi Sato, Shingo Kodaira, Takeshi Okuyama, Yun Luo, Tomoyuki Yambe

    APPLIED ELECTROMAGNETICS AND MECHANICS (II) 13 263-+ 2009

    Publisher: JAPAN SOCIETY APPLIED ELECTROMAGNETICS & MECHANICS

    ISSN:1343-2869

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    Artificial-esophagus of less invasive medical applications utilizing unique properties of shape memory alloys (SMAs) with peristaltic motion is proposed. The proposed artificial-esophagus is composed of two SMA springs, PVC tube, and acrylic plate. Its occlusion pressure is experimentally measured, and transport capacity is also measured using pseudo-masticated food. The possibility for fully self-contained artificial-esophagus using SMAs is discussed.

  148. Atrial Vortex Measurement by Magnetic Resonance Imaging Peer-reviewed

    M. Shibata, T. Yambe, Y. Kanke, T. Hayase

    13TH INTERNATIONAL CONFERENCE ON BIOMEDICAL ENGINEERING, VOLS 1-3 23 (1-3) 2254-+ 2009

    Publisher: SPRINGER

    ISSN:1680-0737

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    The clinical meaning of left atrial vortex has been not fully elucidated. We developed a new left atrial model to simulate intra-atrial flow and a simple method to observe atrial vortex by magnetic resonance imaging (MRI). A flow simulation model of the left atrium (LA) was developed based on slices of the LA image acquired by 1.5T MRI scanner system. Images were reconstructed by commercial software and a computational model was created by using tetrahedral mesh. In order to give the model consecutive temporal change, we presumed that deformation of LA is related to mitral valve annular movement. Then we traced its temporal change and approximated. The flow simulation was performed with FLUENT. Pressure boundary conditions were set based on data in a literature. The results of flow simulation in LA were validated qualitatively by MRI velocity mapping. Left atrial vortex was observed in both simulation and MRI velocity mapping. A representative slice to observe left atrial vortex by MRI was determined with the assistance of the simulation model.

  149. Estimation of E-max of Assisted Hearts using Single Beat Estimation Method Peer-reviewed

    T. K. Sugai, A. Tanaka, A. Yoshizawa, Y. Shiraishi, S. Nitta, T. Yambe, A. Baba

    13TH INTERNATIONAL CONFERENCE ON BIOMEDICAL ENGINEERING, VOLS 1-3 23 (1-3) 2177-+ 2009

    Publisher: SPRINGER

    ISSN:1680-0737

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    In many countries, cardiovascular diseases are the main cause of death. Since the whole blood circulation depends on the heart, it cannot rest in order to recover as most of other muscles can. In some patients with not so severe damages in the myocardium, a rotary blood pump (RBP) may temporarily unload the native heart and can permit the recovery of the cardiac function. Since both implantation and withdrawal of the RBP are invasive procedures, the recovery should be detected with accuracy before weaning of the RBP. Therefore, the objective of this study is to estimate the cardiac function of assisted hearts using the maximum ventricular elastance E-max which is a cardiac function index representing the left ventricle contractility. Conventionally, the index E-max has been estimated using left ventricle pressure (LVP) and volume (LVV) during multiple cardiac cycles and under different loads. The two main problems of this method are that a precise measurement of LVV is invasive, and that induced changes in load should be avoided in cardiac patients. The single beat methods have the advantage that can be used with no changes on left ventricle load. In particular, the parameter optimization method (POM) permits E-max also to be calculated also using flow instead of volume in the case of non-assisted hearts. The conventional estimation of E-max and also the estimation using the POM with LVP and LVV had already been validated under the assistance of the RBP. This study shows that, in particular in cases with non-opening of the aortic valve, E-max can also be estimated by the POM using pump flow instead of LVV.

  150. First Trial of the Chronic Animal Examination of the Artificial Myocardial Function Peer-reviewed

    Y. Shiraishi, T. Yambe, Y. Saijo, K. Matsue, M. Shibata, H. Liu, T. Sugai, A. Tanaka, S. Konno, H. Song, A. Baba, K. Imachi, M. Yoshizawa, S. Nitta, H. Sasada, K. Tabayashi, R. Sakata, Y. Sato, M. Umezu, D. Homma

    13TH INTERNATIONAL CONFERENCE ON BIOMEDICAL ENGINEERING, VOLS 1-3 23 (1-3) 2268-+ 2009

    Publisher: SPRINGER

    ISSN:1680-0737

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    Thromboembolic and haemorrhagic complications are the primary causes of mortality and morbidity in patients with artificial hearts, which are known to be induced by the interactions between blood flow and artificial material surfaces. The authors have been developing a new mechanical artificial myocardial assist device by using a sophisticated shape memory alloy fibre in order to achieve the mechanical cardiac support from outside of the heart without a direct blood contacting surface. The original material employed as the actuator of artificial myocardial assist devices was 100um fibred-shaped, which was composed of covalent and metallic bonding structure and designed to generate 4-7 % shortening by Joule heating induced by the electric current input. Prior to the experiment, the myocardial streamlines were investigated by using a MDCT, and the design of artificial myocardial assist devices were refined based on the concept of Torrent-Guasp's myocardial band theory. As the hydrodynamic or hemodynamic examination exhibited the remarkable increase of cardiac systolic work by the assistance of the artificial myocardial contraction in the originally designed mock circulatory system as well as in the acute animal experiments, the chronic animal test has been started in a goat. Total weight of the device including the actuator was around 150g, and the electric power was supplied percutaneously. The device could be successfully installed into thoracic cavity, which was able to be girdling the left ventricle. In the chronic animal trial, the complication in respect to the diastolic dysfunction by the artificial myocardial compression was not observed.

  151. Numerical Experiment of Transient and Steady Characteristics of Ultrasonic-Measurement-Integrated Simulation in Three-Dimensional Blood Flow Analysis Peer-reviewed

    Kenichi Funamoto, Toshiyuki Hayase, Yoshifumi Saijo, Tomoyuki Yambe

    ANNALS OF BIOMEDICAL ENGINEERING 37 (1) 34-49 2009/01

    Publisher: SPRINGER

    DOI: 10.1007/s10439-008-9600-2  

    ISSN:0090-6964

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    In ultrasonic-measurement-integrated (UMI) simulation of blood flows, feedback signals proportional to the difference of velocity vector optimally estimated from Doppler velocities are applied in the feedback domain to reproduce the flow field. In this paper, we investigated the transient and steady characteristics of UMI simulation by numerical experiment. A steady standard numerical solution of a three-dimensional blood flow in an aneurysmal aorta was first defined with realistic boundary conditions. The UMI simulation was performed assuming that the realistic velocity profiles in the upstream and downstream boundaries were unknown but that the Doppler velocities of the standard solution were available in the aneurysmal domain or the feedback domain by virtual color Doppler imaging. The application of feedback in UMI simulation resulted in a computational result approach to the standard solution. As feedback gain increased, the error decreased faster and the steady error became smaller, implying the traceability to the standard solution improves. The positioning of ultrasound probes influenced the result. The height less than or equal to the aneurysm seemed better choice for UMI simulation using one probe. Increasing the velocity information by using multiple probes enhanced the UMI simulation by achieving ten times faster convergence and more reduction of error.

  152. Automobile, which can control an autonomic nervous system Invited Peer-reviewed

    T. Yambe, Y. Shiraishi, M. Takashima, T. Seki, R. Kawashima

    IFMBE Proceedings 25 (9) 115-118 2009

    DOI: 10.1007/978-3-642-03889-1-31  

    ISSN:1680-0737

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    By the use of the vehicle, function of the Human body has been expanded more and more in the history. If human body will be connected to the vehicle, the vehicle will become a part of a human body. In the previous reports, several investigators have been studying about the man-machine interface. Furthermore, we added the therapeutic effect for the autonomic nervous system during driving in this study. ECG and pulse wave recording system was added to the handle and drive console in the experimental system. Air pressure sensors to detect the respiration and aortic pulse wave were inserted into the drive seat. By the evaluation of the ECG and pulse wave, we can evaluate the circulation dynamics, and furthermore, we can evaluate the pulse wave velocity and fluctuations in hemodynamic derivatives. By the use of this information, several kinds of Aroma, Massage to the Acu-point or the Moxibustion were added to the driver. So, the automobile can control the autonomic nerve condition during driving. After ethical committee allowance we evaluated the effect of aroma and moxibustion therapy on driver. Hemodynamics, HRV and baroreflex system was tended to altered depending of the kinds of Aroma, acupuncture point stimulation with massage and moxibustion. These results suggest that vehicle can become artificial automatic nerve controller in future. © 2009 Springer-Verlag.

  153. Nano technology for the development of artificial internal organs Peer-reviewed

    T. Yambe, Y. Shiraishi, H. Miura, G. Miyata, K. Tabayashi, K. Imachi

    IFMBE Proceedings 25 (7) 536-539 2009

    DOI: 10.1007/978-3-642-03885-3-149  

    ISSN:1680-0737

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    Everybody knows that smaller is better when we consider the development of an internal artificial organ system. For the development of smaller and light weight internal artificial organs, micromachining technology and nano technology will have the possibility of the usefulness. For example, artificial sphincter, artificial esophagus, super stent system, convulsion stop machine, artificial heart, ventricular assist device, artificial myocardium system are now under development by the use of various kinds of nano technologies. Furthermore, implantable artificial organ system enables the patients to come back to their homes. So, not only for the life of the patients, but also for the QOL of the patients, nanotechnology will be useful in the development in near future. © 2009 Springer-Verlag.

  154. 形状記憶合金人工心筋駆動下の自律神経活動と圧反射感受性解析の試み Peer-reviewed

    劉紅箭, 白石泰之, 鄭徳泳, 羅雲, 山家智之

    人工臓器 37 (2) S-163 2008/11

  155. 光電容積脈波を用いた映像酔いの生体影響評価 Peer-reviewed

    阿倍誠, 吉沢誠, 杉田典大, 田中明, 千葉滋, 山家智之, 仁田新一

    ヒューマンインターフェース学会誌 199-205 2008/10

  156. Numerical experiment for Ultrasonic-Measurement-Integrated simulation of three-dimensional unsteady blood flow Peer-reviewed

    Kenichi Funamoto, Toshiyuki Hayase, Yoshifumi Saijo, Tomoyuki Yambe

    ANNALS OF BIOMEDICAL ENGINEERING 36 (8) 1383-1397 2008/08

    Publisher: SPRINGER

    DOI: 10.1007/s10439-008-9519-7  

    ISSN:0090-6964

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    Integration of ultrasonic measurement and numerical simulation is a possible way to break through limitations of existing methods for obtaining complete information on hemodynamics. We herein propose Ultrasonic-Measurement-Integrated (UMI) simulation, in which feedback signals based on the optimal estimation of errors in the velocity vector determined by measured and computed Doppler velocities at feedback points are added to the governing equations. With an eye towards practical implementation of UMI simulation with real measurement data, its efficiency for three-dimensional unsteady blood flow analysis and a method for treating low time resolution of ultrasonic measurement were investigated by a numerical experiment dealing with complicated blood flow in an aneurysm. Even when simplified boundary conditions were applied, the UMI simulation reduced the errors of velocity and pressure to 31% and 53% in the feedback domain which covered the aneurysm, respectively. Local maximum wall shear stress was estimated, showing both the proper position and the value with 1% deviance. A properly designed intermittent feedback applied only at the time when measurement data were obtained had the same computational accuracy as feedback applied at every computational time step. Hence, this feedback method is a possible solution to overcome the insufficient time resolution of ultrasonic measurement.

  157. 脈診に科学的根拠はあるのか? Invited

    山家智之

    日本統合医療学会誌 1 (1) 71-78 2008/07

  158. ナノDLCセンサ内蔵てんかん自動診断治療装置

    山家智之

    てんかん治療研究振興財団研究年報 19 84-94 2008/06

  159. 形状記憶合金アクチュエータによる蠕動運動を有する人工食道の開発 Peer-reviewed

    三木寛之, 羅雲, 山家智之, 小平真吾, 奥山武史

    日本機械学会 182-183 2008/06

  160. ふく射加熱装置を用いた熱流束制御による温熱療法への応用 Peer-reviewed

    小笠原直也, 高島茂, 関隆志, 円山重直, 小宮敦樹, 山家智之

    日本伝熱シンポジウム講演論文集 45 (2) 821-824 2008/06

  161. 【食道疾患の臨床 update】 食道癌 食道癌ステント治療の未来 Invited Peer-reviewed

    山家智之, 白石泰之, 西條芳文, 宮田剛, 里見進, 佐藤文博, 松木英敏, 関根一光

    臨床消化器内科 23 (7) 1056-1059 2008/05

  162. 酸素付加能を有する振動流人工心臓の開発とその牛血実験 Peer-reviewed

    新宅博文, 米村翼, 磯山隆, 山家智之, 川野聡恭

    日本機械学会論文集 74 (740) 96-1004 2008/04

    DOI: 10.1299/kikaib.74.862  

  163. Interpolation of the subjective score of visually-induced motion sickness by using physiological parameters. Peer-reviewed

    Tanaka Akira, Sugita Norihiro, Yoshizawa Makoto, Abe Makoto, Yambe Tomoyuki

    Conf Proc IEEE Eng Med Biol Soc 2008 4595-4596 2008/04

    DOI: 10.1109/IEMBS.2008.4650236  

  164. A method for evaluating effects of visually-induced motion sickness using ICA for photoplethysmography. Peer-reviewed

    Abe Makoto, Yoshizawa Makoto, Sugita Norihiro, Tanaka Akira, Chiba Shigeru, Yambe Tomoyuki, Nitta Shin-Ichi

    Conf Proc IEEE Eng Med Biol Soc 2008 4591-4594 2008/04

    DOI: 10.1109/IEMBS.2008.4650235  

  165. Comparison of maximum cross-correlation coefficient between blood pressure and heart rate with traditional index associated with baroreflex sensitivity. Peer-reviewed

    Sugita Norihiro, Yoshizawa Makoto, Abe Makoto, Tanaka Akira, Chiba Shigeru, Yambe Tomoyuki, Nitta Shin-ichi

    Conf Proc IEEE Eng Med Biol Soc 2008 2574-2577 2008/04

    DOI: 10.1109/IEMBS.2008.4649726  

  166. Preliminary study on the estimation of Emax using single-beat methods during assistance with rotary blood pumps. Peer-reviewed

    Sugai Telma Keiko, Tanaka Akira, Yoshizawa Makoto, Shiraishi Yasuyuki, Baba Atsushi, Yambe Tomoyuki, Nitta Shin-ichi

    Conf Proc IEEE Eng Med Biol Soc 2008 973-976 2008/04

    DOI: 10.1109/IEMBS.2008.4649317  

  167. Swallow stent with hyperthermia function. Peer-reviewed

    Yambe Tomoyuki, Sato Fumihiro, Matsuki Hidetoshi, Shiraishi Yasuyuki, Miyata Go, Satomi Susumu

    Conf Proc IEEE Eng Med Biol Soc 2008 731-734 2008/04

    DOI: 10.1109/IEMBS.2008.4649256  

  168. Sensorless control for a sophisticated artificial myocardial contraction by using shape memory alloy fibre. Peer-reviewed

    Shiraishi Y, Yambe T, Saijo Y, Sato F, Tanaka A, Yoshizawa M, Sugai T K, Sakata R, Luo Y, Park Y, Uematsu M, Umezu M, Fujimoto T, Masumoto N, Liu H, Baba A, Konno S, Nitta S, Imachi K, Tabayashi K, Sasada H, Homma D

    Conf Proc IEEE Eng Med Biol Soc 2008 711-714 2008/04

    DOI: 10.1109/IEMBS.2008.4649251  

  169. Fractal dimension of 40 MHz intravascular ultrasound radio frequency signals Peer-reviewed

    E. Santos Filho, Y. Saijo, A. Tanaka, T. Yambe, M. Yoshizawa

    ULTRASONICS 48 (1) 35-39 2008/03

    Publisher: ELSEVIER SCIENCE BV

    DOI: 10.1016/j.ultras.2007.08.006  

    ISSN:0041-624X

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    Objective: Fully automatic tissue characterization in intravascular ultrasound systems is still a challenge for the researchers. The present work aims to evaluate the feasibility of using the Higuchi fractal dimension of intravascular ultrasound radio frequency signals as a feature for tissue characterization. Methods: Fractal dimension images are generated based on the radio frequency signals obtained using mechanically rotating 40 MHz intravascular ultrasound catheter (Atlantis SR Plus, Boston Scientific, USA) and compared with the corresponding correlation images. Conclusion: An inverse relation between the fractal dimension images and the correlation images was revealed indicating that the hard or slow moving tissues in the correlation image usually have low fractal dimension and vice-versa. Thus, the present study suggests that fractal dimension images may be used as a feature for intravascular ultrasound tissue characterization and present better resolution then the correlation images. (C) 2007 Elsevier B.V. All rights reserved.

  170. より豊かな生活に貢献する医療技術に関する研究 てんかん発作のコントロールによりQOLの向上を目指した新しい人工内臓 Invited

    山家智之, 浅野英司, 阿部裕輔, 松木英敏, 圓山重直

    医科学応用研究財団研究報告 25 135-137 2008/02

  171. ハイパーサーミア蠕動ステント Invited Peer-reviewed

    山家智之

    Thermal Medicine 23 (4) 151-158,(123) 2007/12

    Publisher: Japanese Society for Thermal Medicine

    DOI: 10.3191/thermalmed.23.151  

    ISSN:1882-2576

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    Surgery for esophageal cancer is a very difficult operation, even today with modern medical techniques. One of the most important aspects of such surgery is the difficulty of reconstructing the esophagus. In such a surgical procedure, the stomach and intestines are used to provide material to repair any esophageal damage, thus requiring a large and extensive operation which is difficult with elderly patients. Although an improvement in prognosis for the quality of life can be expected if the cancer is resectable, there are a many cases which are diagnosed too late for effective surgery. To help these patients, a peristalsis stent with a hyperthermia function was developed for use with terminal esophageal cancer patients when surgery is not an option. The peristalsis stent with a hyperthermia function has three characteristics : 1) It is completely noninvasive ; 2) hyperthermia can be delivered to the carcinoma tissue ; and 3) it incorporates a peristalsis function. This stent is expected to provide an alternative tool for the treatment of terminal esophageal cancer.

  172. Macrophage colony-stimulating factor improves cardiac function after ischemic injury by inducing vascular endothelial growth factor production and survival of cardiomyocytes Peer-reviewed

    Tatsuma Okazaki, Satoru Ebihara, Masanori Asada, Shinsuke Yamanda, Yoshifumi Saijo, Yasuyuki Shiraishi, Takae Ebihara, Kaijun Niu, He Mei, Hiroyuki Arai, Tomoyuki Yambe

    AMERICAN JOURNAL OF PATHOLOGY 171 (4) 1093-1103 2007/10

    Publisher: AMER SOC INVESTIGATIVE PATHOLOGY, INC

    DOI: 10.2353/ajpath.2007.061191  

    ISSN:0002-9440

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    Macrophage colony-stimulating factor (M-CSF), known as a hematopoictic growth factor, induces vascular endothelial growth factor (VEGF) production from skeletal muscles. However, the effects of M-CSF on cardiomyocytes; have not been reported. Here, we show M-CSF increases VEGF production from cardiomyocytes, protects cardiomyocytes; and myotubes from cell death, and improves cardiac function after ischemic injury. in mice, M-CSF increased VEGF production in hearts and in freshly isolated cardiomyocytes, which showed M-CSF receptor expression. In rat cell fine H9c2 cardiomyocytes and myotubes, M-CSF induced VEGF production via the Akt signaling pathway, and M-CSF pretreatment protected these cells from H2O2-induced cell death. MCSF activated Akt and extracellular signal-regulated kinase signaling pathways and up-regulated downstream anti-apoptotic Bcl-xL expression in these cells. Using goats as a large animal model of myocardial infarction, we found that M-CSF treatment after the onset of myocardial infarction by permanent coronary artery ligation promoted angiogenesis in ischemic hearts but did not reduce the infarct area. M-CSF pretreatment of the goat myocardial infarction model by coronary artery occlusion-reperfusion improved cardiac function, as assessed by hemodynamic parameters and echocardiography. These results suggest M-CSF might be a novel therapeutic agent for ischemic heart disease.

  173. Acute and chronic consequences of non-pulsatile blood flow pattern in long-term total artificial heart experiment Peer-reviewed

    Jaromír Vašků, Jiří Wotke, Petr Dobšák, Atsushi Baba, Aleš Rejthar, Šárka Kuchtíčková, Kou Imachi, Yusuke Abe, Itsuro Saito, Takashi Isoyama, Shin-ichi Nitta, Tomoyuki Yambe

    Pathophysiology 14 (2) 87-95 2007/10

    DOI: 10.1016/j.pathophys.2007.06.002  

    ISSN:0928-4680

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    Vessel pulsation is presumably a key physiological function for the optimal supply of peripheral tissues and vital organs by oxygen and nutrients. The absence of pulsatility might impair the peripheral perfusion stability and trigger microvascular dysfunction of vital organs. The main purpose of this study was to investigate the influence of non-pulsatile flow on the microcirculation in experimental goat with implanted undulation pump total artificial heart (UPTAH). A microscopic system (Keyence, Japan) for the direct observation of the microcirculation of bulbar conjunctiva was used. Following the acute flow pattern change (from pulsatile to non-pulsatile one), the number of perfused capillaries decreased significantly (from 34.7 ± 6.3 to 19.7 ± 4.1 number of capillaries/mm P &lt 0.05). The velocity of erythrocytes dropped (from 526 ± 83 to 132 ± 41 μm/s P &lt 0.05). The velocity of erythrocytes and capillary density were only partly recovered, when the pulsatile flow mode was restored. Histopathological analysis after 33 days of pumping in non-pulsatile mode revealed the presence of chronic venostasis, tissue edema, hemorrhages, hypoxia and ischemic necroses in the tissue samples from liver, kidneys and lung. These findings could be regarded as a direct effect of the chronic non-pulsatile pumping mode and inadequate blood supply. We conclude that the presence of pulsatile flow should be considered as a vital condition for a successful long-term survival after total artificial heart implantation. © 2007 Elsevier Ireland Ltd. All rights reserved.

  174. アロマ刺激時の生体自律神経機能、ストレス指標と脳活動との関連性 Peer-reviewed

    段旭東, 田代学, 三宅正泰, 四月朔日聖一, 山家智之, 瀬戸小百合, 伊藤正敏

    核医学 44 (3) 279-279 2007/10

  175. 医工学による右心流出路再建の評価方法

    末永健, 白石泰之, 西條芳文, 山家智之, 馮忠剛, 中村孝夫, 宮崎隆子, 山岸正明, 田中隆, 岡本吉弘, 梅津光生

    人工臓器 36 (2) S109-S109 2007/10

  176. Cardiopulmonary 定常流型補助人工心臓の制御方式の相違が自己心に与える影響

    笠原孝一郎, 田中明, 吉澤誠, 阿部健一, 白石泰之, 山家智之, 仁田新一

    人工臓器 36 (2) S62-S62 2007/10

  177. 脈波伝播速度と加齢に関する国際共同研究

    山家智之, 杉田典大, 吉澤誠, MilyaginViktor

    日本臨床生理学会雑誌 37 (5) 76-76 2007/10

  178. 病態生理 心血管調節の機構 血圧反射システムを介した血管調節機構の定量診断装置の開発

    山家智之, 杉田典大, 吉澤誠

    日本臨床生理学会雑誌 37 (5) 66-66 2007/10

  179. 脈波波形の立ち上がりポイント診断法の方法論の正確性に関する比較研究

    山家智之, 片平美明, 吉澤誠, 丸山満也, 山口佑, 仁田新一

    日本高血圧学会総会プログラム・抄録集 30回 254-254 2007/10

  180. Evaluation of adaptation to visually induced motion sickness based on the maximum cross-correlation between pulse transmission time and heart rate Peer-reviewed

    Norihiro Sugita, Makoto Yoshizawa, Makoto Abe, Akira Tanaka, Takashi Watanabe, Shigeru Chiba, Tomoyuki Yambe, Shin-ichi Nitta

    JOURNAL OF NEUROENGINEERING AND REHABILITATION 4 35-35 2007/09

    Publisher: BIOMED CENTRAL LTD

    DOI: 10.1186/1743-0003-4-35  

    ISSN:1743-0003

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    Background: Computer graphics and virtual reality techniques are useful to develop automatic and effective rehabilitation systems. However, a kind of virtual environment including unstable visual images presented to wide field screen or a head mounted display tends to induce motion sickness. The motion sickness induced in using a rehabilitation system not only inhibits effective training but also may harm patients' health. There are few studies that have objectively evaluated the effects of the repetitive exposures to these stimuli on humans. The purpose of this study is to investigate the adaptation to visually induced motion sickness by physiological data. Methods: An experiment was carried out in which the same video image was presented to human subjects three times. We evaluated changes of the intensity of motion sickness they suffered from by a subjective score and the physiological index rho(max), which is defined as the maximum cross-correlation coefficient between heart rate and pulse wave transmission time and is considered to reflect the autonomic nervous activity. Results: The results showed adaptation to visually-induced motion sickness by the repetitive presentation of the same image both in the subjective and the objective indices. However, there were some subjects whose intensity of sickness increased. Thus, it was possible to know the part in the video image which related to motion sickness by analyzing changes in. max with time. Conclusion: The physiological index,. max, will be a good index for assessing the adaptation process to visually induced motion sickness and may be useful in checking the safety of rehabilitation systems with new image technologies.

  181. Ultrasonic tissue characterization of atherosclerosis by a speed-of-sound microscanning system Peer-reviewed

    Yoshifumi Saijo, Esmeraldo Santos Filho, Hidehiko Sasaki, Tomoyuki Yambe, Motonao Tanaka, Naohiro Hozumi, Kazuto Kobayashi, Nagaya Okada

    IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL 54 (8) 1571-1577 2007/08

    Publisher: IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

    DOI: 10.1109/TUFFC.2007.427  

    ISSN:0885-3010

    eISSN:1525-8955

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    We have been developing a scanning acoustic microscope (SAM) system for medicine and biology featuring quantitative measurement of ultrasonic parameters of soft tissues. In the present study, we propose a new concept sound speed microscopy that can measure the thickness and speed of sound in the tissue using fast Fourier transform of a single pulsed wave instead of burst waves used in conventional SAM systems. Two coronary arteries were frozen and sectioned approximately 10 mu m in thickness. They were mounted on glass slides without cover slips. The scanning time of a frame with 300 x 300 pixels was 90 s and two-dimensional distribution of speed of sound was obtained. The speed of sound was 1680 30 m/s in the thickened intima with collagen fiber, 1520 8 m/s in the lipid deposition underlying the fibrous cap, and 1810 25 m/s in a calcified lesion in the intima. These basic measurements will help in the understanding of echo intensity and pattern in intravascular ultrasound images.

  182. 定常流型補助人工心臓と心機能に関する実験的研究

    山家智之, 白石泰之, 田林晄一, 吉澤誠

    Journal of Cardiology 50 (Suppl.I) 567-567 2007/08

  183. オプティカルフロー法による心血管内血流の可視化

    西條芳文, 田中明, 田林晄一, 山家智之

    Journal of Cardiology 50 (Suppl.I) 379-379 2007/08

  184. Pre-hypertension(前高血圧)の病態と臨床的意義 新しい動脈の血圧反射機能感受性診断装置の発明による高血圧の発症予測

    山家智之, 吉澤誠, 杉田典大, 田中明

    Journal of Cardiology 50 (Suppl.I) 149-149 2007/08

  185. 脈波の立ち上がりポイント測定の正確性に関する臨床研究 Invited Peer-reviewed

    山家智之, 東北大学加齢医学研究所, 西條芳文, 白石泰之, 川田浩, 金野敏, 仁田新一, 山口済, 中島博行, 片平美明, 柴田宗一, 渡辺誠, 三引義明, 大沢上, 佐藤尚, 秋野能久, 本多正久

    エレクトロニクスの臨床(0913-3887)76号 Page23-34(2007.07) 76 23-34 2007/07

  186. 脈波の立ち上がりポイント測定の正確性に関する臨床研究 Invited Peer-reviewed

    山家智之, 西條芳文, 白石泰之, 川田浩, 金野敏, 仁田新一, 山口済, 中島博行, 片平美明, 柴田宗一, 渡辺誠, 三引義明, 大沢上, 佐藤尚, 秋野能久, 本多正久

    エレクトロニクスの臨床 (76) 23-34 2007/07

  187. 基礎医学から 「超」食道ステント Invited

    山家智之

    日本医事新報 (4341) 68-71 2007/07

  188. 動脈の血圧反射機能感受性診断装置の発明 Invited

    山家智之, 川田浩, 丸山満也, 金野敏, 西條芳文, 白石泰之, 仁田新一, 吉澤誠, 杉田典大, 田中明, 宗像正徳, 山口佑, 片平美明, 秋野能久, 本多正久, 柴田宗一, 渡辺誠, 三引義明, 大沢上, 佐藤尚

    東北医学雑誌 119 (1) 73-77 2007/06

  189. 動脈と心臓の血圧反射機能の感受性を同時に定量的に計測できる新しい診断装置の発明

    山家智之, 吉澤誠, 杉田典大

    日本動脈硬化学会総会プログラム・抄録集 39回 282-282 2007/06

  190. Stiffness parameter βを反映したCAVIと加齢に関する日露国際共同研究

    山家智之, ビクター・ミラーゲン, ユーリ・コバレフ, イリーナ・ミリャジーナ, 仁田新一

    日本動脈硬化学会総会プログラム・抄録集 39回 268-268 2007/06

  191. 形状記憶合金を用いた人工的蠕動運動型人工食道

    関根一光, 山家智之, 西條芳文, 白石泰之, 松木英敏, 佐藤文博, 前田剛, 中澤文雄

    北海道外科雑誌 52 (1) 85-85 2007/06

  192. 鍼灸所見の臨床的意義と客観化 六部定位の脈診について 脈波情報の客観化と脈診 Invited Peer-reviewed

    丸山満也, 金野敏, 仁田新一, 高島充, 白石泰之, 山家智之, 関隆志, 荒井啓行, 太田信, 劉磊, 白井敦, 早瀬敏幸

    全日本鍼灸学会雑誌 57 (2) 116-118 2007/05

    DOI: 10.3777/jjsam.57.110  

  193. Estimation of effects of visually-induced motion sickness using independent component analysis. Peer-reviewed

    Abe Makoto, Yoshizawa Makoto, Sugita Norihiro, Tanaka Akira, Chiba Shigeru, Yambe Tomoyuki, Nitta Shin-ichi

    Conf Proc IEEE Eng Med Biol Soc 2007 5501-5504 2007/04

    DOI: 10.1109/IEMBS.2007.4353591  

  194. Morphological approach for the functional improvement of an artificial myocardial assist device using shape memory alloy fibres. Peer-reviewed

    Shiraishi Y, Yambe T, Saijo Y, Sato F, Tanaka A, Yoshizawa M, Ogawa D, Wada Y, Itoh S, Sakata R, Park Y, Uematsu M, Umezu M, Fujimoto T, Masumoto N, Liu H, Baba A, Konno S, Nitta S, Imachi K, Tabayashi K, Sasada H, Homma D

    Conf Proc IEEE Eng Med Biol Soc 2007 3974-3977 2007/04

    DOI: 10.1109/IEMBS.2007.4353204  

  195. Ultrasound speed and impedance microscopy for in vivo imaging. Peer-reviewed

    Saijo Yoshifumi, Hozumi Naohiro, Kobayashi Kazuto, Okada Nagaya, Ishiguro Toshimichi, Hagiwara Yoshihiro, dos Santos Filho Esmeraldo, Yambe Tomoyuki

    Conf Proc IEEE Eng Med Biol Soc 2007 1350-1353 2007/04

    DOI: 10.1109/IEMBS.2007.4352548  

  196. Evaluation of adaptation to visually induced motion sickness by using physiological index associated with baroreflex function. Peer-reviewed

    Sugita Norihiro, Yoshizawa Makoto, Abe Makoto, Tanaka Akira, Chiba Shigeru, Yambe Tomoyuki, Nitta Shin-ichi

    Conf Proc IEEE Eng Med Biol Soc 2007 303-306 2007/04

    DOI: 10.1109/IEMBS.2007.4352284  

  197. Nanotechnology in artificial organ development and its application in diagnosis methodology in baroreflex sensitivity of the patients with hypertension Peer-reviewed

    Yambe T Yoshizawa, M Sugita, N, Tanaka A, K. Imachi

    Biocybernetics and Biomedical Engineering 26 65-70 2007/03/02

  198. 【機械的循環制御】 定常流型補助人工心臓の循環制御は不要か? Invited Peer-reviewed

    吉澤誠, 田中明, 小川大祐, 笠原孝一郎, ポール・オレガリオ, 白石泰之, 関根一光, 山家智之, 仁田新一

    循環制御 28 (1) 4-11 2007/03

  199. Support mechanism of a newly-designed mechanical artificial myocardium using shape memory alloy fibres

    Yasuyuki Shiraishi, T. Yambe, S. Itoh, R. Sakata, Y. Wada, K. Sekine, Y. Saijo, S. Konno, S. Nitta, Q. Wang, H. Liu, M. Higa, Y. Luo, D. Ogawa, A. Tanaka, M. Yoshizawa, Y. Kakubari, H. Miura, F. Sato, H. Matsuki, M. Uematsu, Y. Park, T. Tanaka, M. Umezu, T. Fujimoto, N. Masumoto, Y. Hori, H. Sasada, K. Tabayashi, E. Okamoto, D. Homma

    IFMBE Proceedings 14 (1) 3161-3164 2007

    DOI: 10.1007/978-3-540-36841-0_799  

    ISSN:1680-0737

    eISSN:1433-9277

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    As the heart failure is caused by the decrease in the myocardial contraction, the direct mechanical myocardial assistance in response to physiological demand, that is, the synchronous support of the contractile function from outside of the heart, might be effective. The purpose of this study was to develop an artificial myocardium which was capable of supporting the cardiac contraction directly by using the shape memory alloy fibres based on nanotechnology. Some methodologies using novel devices other than the artificial hearts are proposed so far with severe heart disease. However, it was also anticipated that the decrease in cardiac functions owing to the diastolic disability might be caused by using those ‘static’ devices. Then, this study was focused on an artificial myocardium using shape memory alloy fibres with a diameter of 100 – 150 um, and the authors examined its mechanism in a mock circulatory system as well as in animal experiments using goats. Basic characteristics of the material were evaluated prior to the hydrodynamic or hemodynamic examination using a mock ventricular model. The results were as follows: a) The length of the structure was able to be adjusted so that the system could wrap the whole heart effectively. b) In the hydrodynamic study using the mock circulatory system, the myocardial system was able to pump a flow against the afterload of arterial pressure level. c) In the animal experiments, aortic pressure and flow rate were elevated by 7 and 15% respectively by the mechanical assistance of the artificial myocardium, which was driven synchronising with the electrocardiogram, and also, d) The anatomically-identical shape of the artificial myocardium might be more effective for the assistance. In conclusion, it was indicated that this controllable artificial myocardial support system was effective for the mechanical cardiac support for the chronic heart failure.

  200. Development of the displacement amplification mechanism for myocardial assist device

    Watabe Tomoki, Shiraishi Yasuyuki, Wada Yumiko, Sakata Ryo, Saijo Yoshifumi, Yambe Tomoyuki, Homma Dai, Shibata Souichi, Umezu Mitsuo

    Journal of Life Support Technology 19 192-192 2007

    Publisher: The Society of Life Support Engineering

    DOI: 10.5136/lifesupport.19.Supplement_192  

    ISSN:1341-9455

  201. Morphological approach for the functional improvement of an artificial myocardial assist device using shape memory alloy fibres Peer-reviewed

    Y. Shiraishi, T. Yambe, Y. Saijo, F. Sato, A. Tanaka, M. Yoshizawa, D. Ogawa, Y. Wada, S. Itoh, R. Sakata, Y. Park, M. Uematsu, M. Umezu, T. Fujimoto, N. Masumoto, H. Liu, A. Baba, S. Konno, S. Nitta, K. Imachi, K. Tabayashi, H. Sasada, D. Homma

    Annual International Conference of the IEEE Engineering in Medicine and Biology - Proceedings 3974-3977 2007

    DOI: 10.1109/IEMBS.2007.4353204  

    ISSN:0589-1019

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    The authors have been developing a mechano-electric artificial myocardial assist system (artificial myocardium) which is capable of supporting natural contractile functions from the outside of the ventricle without blood contacting surface. In this study, a nano-tech covalent type shape memory alloy fibre (Biometal, Toki Corp, Japan) was employed and the parallel-link structured myocardial assist device was developed. And basic characteristics of the system were examined in a mechanical circulatory system as well as in animal experiments using goats. The contractile functions were evaluated with the mock circulatory system that simulated systemic circulation with a silicone left ventricular model and an aortic afterload. Hemodynamic performance was also examined in goats. Prior to the measurement, the artificial myocardial assist device was installed into the goat's thoracic cavity and attached onto the ventricular wall. As a result, the system could be installed successfully without severe complications related to the heating, and the aortic flow rate was increased by 15% and the systolic left ventricular pressure was elevated by 7% under the cardiac output condition of 3L/min in a goat. And those values were elevated by the improvement of the design which was capable of the natural morphological myocardial tissue streamlines. Therefore it was indicated that the effective assistance might be achieved by the contraction by the newly-designed artificial myocardial assist system using Biometal. Moreover it was suggested that the assistance gain might be obtained by the optimised configuration design along with the natural anatomical myocardial stream line. © 2007 IEEE.

  202. Evaluation of Cardiac Function of the Patients with Left Ventricular Assist Device by Transesophageal Echocardiography Peer-reviewed

    Y. Saijo, Y. Saiki, A. Iguchi, K. Tabayashi, Y. Shiraishi, K. Sekine, T. Yambe

    WORLD CONGRESS ON MEDICAL PHYSICS AND BIOMEDICAL ENGINEERING 2006, VOL 14, PTS 1-6 14 4146-+ 2007

    Publisher: SPRINGER-VERLAG BERLIN

    ISSN:1680-0737

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    The control of left ventricular assist device (LVAD) has been based on pressures of left ventricle (LV), aorta (AO) and pulmonary artery (PA) and flows in AO and PA. These parameters are one-dimensional and suitable for control of LVAD because they are numerical and quantitative. However, evaluation of the cardiac function by echocardiography is very useful in clinical settings because the cardiac function changes rapidly and dramatically. Transesophageal echocardiography is very useful for the assessment of cardiac function of the patients with LVAD implantation because it can detect and visualize what is happening in the heart immediately and directly.

  203. Invention of the totally implantable Epilepsy control machine by the use of Nano technology

    Yambe T Masuyama, S Takeda, H, Asano E

    Proceed 9th International Symposium on Future Medical Engineering based on Bio nano Technology 2007 131-132 2007/01

  204. Autonomic nervous function and localization of cerebral activity during lavender aromatic immersion Peer-reviewed

    Xudong Duan, Manabu Tashiro, Di Wu, Tomoyuki Yambe, Qingtian Wang, Takehisa Sasaki, Kazuaki Kumagai, Yun Luo, Shin-Ichi Nitta, Masatoshi Itoh

    Technology and Health Care 15 (2) 69-78 2007

    ISSN:0928-7329

    More details Close

    Changes in the autonomic nervous activity can be induced by various sensory and emotional stimuli. The authors examined whether the power spectral analysis of heart rate variability (HRV) could detect changes in autonomic tone following a lavender aroma treatment or not. Healthy young women (n=10, 23±3 years old) underwent continuous electrocardiographic (ECG) monitoring before and after (10, 20, 30 minutes) the lavender fragrance stimuli. HRV was expressed by three indices: low (0.04-0.15 Hz) and high (0.15-0.40 Hz) frequency components (nLF and nHF, respectively) as well as LF/HF ratio. Increases in the parasympathetic tone were observed after the lavender fragrance stimulus as seen as increases in the HF component and decreases in the LF/HF. Additional measurement with positron emission tomography (PET) demonstrated the regional metabolic activation in the orbitofrontal, posterior cingulate gyrus, brainstem, thalamus and cerebellum, as well as the reductions in the pre/post-central gyrus and frontal eye field. These results suggested that lavender aromatic treatment induced not only relaxation but also increased arousal level in these subjects. © 2007 - IOS Press and the authors. All rights reserved.

  205. Biochemical evaluation of an artificial anal sphincter made from shape memory alloys Peer-reviewed

    Hongjian Liu, Yun Luo, Masaru Higa, Xiumin Zhang, Yoshifumi Saijo, Yasuyuki Shiraishi, Kazumitsu Sekine, Tomoyuki Yambe

    JOURNAL OF ARTIFICIAL ORGANS 10 (4) 223-227 2007

    Publisher: SPRINGER TOKYO

    DOI: 10.1007/s10047-007-0395-y  

    ISSN:1434-7229

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    Severe anal incontinence is a socially incapacitating disorder and a major unresolved clinical problem that has a considerable negative impact on quality of life. In this study, we developed a new artificial anal sphincter using shape memory alloys (SMAs) in order to improve the quality of life of such patients and evaluated the influence of this sphincter on blood serum chemistry in animal experiments. The artificial anal sphincter was driven by two Ti-Ni SMA actuators sandwiching the intestine and was implanted in three female goats. Blood was collected from the jugular vein on days 1 and 4; at weeks 1 and 2; and at months 1, 2, and 3, postoperatively. Biochemical parameters including total protein, albumin, total bilirubin, aspartate aminotransferase, blood urea nitrogen, creatinine, and C-reactive protein were examined. The time courses of total bilirubin and aspartate amino transferase of the three goats were within the baseline levels after I week of implantation and remained normal, demonstrating no liver function complications. The blood urea nitrogen and creatinine levels remained within the normal range, indicating no renal function complications. The total protein and albumin fluctuated within the normal range throughout the duration of this study. In these goats, it was also found that the level of Creactive protein did not increase and that there was no stricture of the intestine where the artificial sphincter was attached. Our findings indicate that the artificial sphincter SMA demonstrated no adverse influence on blood serum chemistry and exhibited an effective system performance.

  206. Autonomic nervous function and localization of cerebral activity during lavender aromatic immersion Peer-reviewed

    Xudong Duan, Manabu Tashiro, Di Wu, Tomoyuki Yambe, Qingtian Wang, Takehisa Sasaki, Kazuaki Kumagai, Yun Luo, Shin-Ichi Nitta, Masatoshi Itoh

    Technology and Health Care 15 (2) 69-78 2007

    ISSN:0928-7329

    More details Close

    Changes in the autonomic nervous activity can be induced by various sensory and emotional stimuli. The authors examined whether the power spectral analysis of heart rate variability (HRV) could detect changes in autonomic tone following a lavender aroma treatment or not. Healthy young women (n=10, 23±3 years old) underwent continuous electrocardiographic (ECG) monitoring before and after (10, 20, 30 minutes) the lavender fragrance stimuli. HRV was expressed by three indices: low (0.04-0.15 Hz) and high (0.15-0.40 Hz) frequency components (nLF and nHF, respectively) as well as LF/HF ratio. Increases in the parasympathetic tone were observed after the lavender fragrance stimulus as seen as increases in the HF component and decreases in the LF/HF. Additional measurement with positron emission tomography (PET) demonstrated the regional metabolic activation in the orbitofrontal, posterior cingulate gyrus, brainstem, thalamus and cerebellum, as well as the reductions in the pre/post-central gyrus and frontal eye field. These results suggested that lavender aromatic treatment induced not only relaxation but also increased arousal level in these subjects. © 2007 - IOS Press and the authors. All rights reserved.

  207. てんかん発作を自分で治す埋め込み型デバイス

    山家智之

    臨床神経学 46 (12) 1099-1099 2006/12

  208. Invention of the new diagnosis tool for the baroreflex sensitivity of the artery for the patients with hypertension.

    Yambe T, Yoshizawa, M Sugita, N, Tanaka A Konno, S Kawada, H, Maruyama M, Nitta

    Proceed 2nd Tohoku-NUS joint Symposium on the future nano medicine and bioengineering in the East Asian Region 2006 76-77 2006/12/01

  209. 人工肺機能付き振動流血液ポンプの改良研究

    磯山隆, 川野聡恭, 笠川哲也, 鎮西恒雄, 斎藤逸郎, 山家智之, 仁田新一, 橋本弘之, 野城真理, 井街宏, 阿部裕輔

    人工臓器 35 (2) S173-S173 2006/10

  210. 形状記憶合金を応用した人工心筋要素の機械特性と駆動制御に関する基礎検討

    伊藤慎二, 白石泰之, 和田由美子, 坂田亮, 植松美幸, 田中隆, 小川大祐, 関根一光, 吉澤誠, 田中明, 西條芳文, 山家智之, 岡本英治, 本間大, 藤本哲男, 梅津光生

    人工臓器 35 (2) S167-S167 2006/10

  211. 長期埋込型形状記憶合金人工括約筋の生体適合性評価

    劉紅箭, 羅雲, 比嘉昌, 西條芳文, 白石泰之, 関根一光, 山家智之

    人工臓器 35 (2) S166-S166 2006/10

  212. 定常流型人工心臓装着時の心機能評価 動物実験およびモデルによる検討

    小川大祐, 田中明, 吉澤誠, 阿部健一, OlegarioPaul, 笠原孝一郎, 白石泰之, 関根一光, 山家智之, 仁田新一

    人工臓器 35 (2) S160-S160 2006/10

  213. 補助人工心臓用制御アルゴリズム開発のための循環系シミュレータ

    笠原孝一郎, 田中明, 吉澤誠, 阿部健一, OlegarioPaul, 小川大祐, 白石泰之, 関根一光, 山家智之, 仁田新一

    人工臓器 35 (2) S159-S159 2006/10

  214. 東北大学における無拍動流左心補助人工心臓EVAHEARTの長期動物実験による評価

    王慶田, 山家智之, 白石泰之, 関根一光, 西條芳文, 仁田新一, 井街宏, 山崎健二, 北野智哉, 山崎俊一

    人工臓器 35 (2) S156-S156 2006/10

  215. 再生医療の評価方法としての高周波数超音波の可能性

    西條芳文, 白石泰之, 関根一光, 山家智之, 佐野博高, 萩原嘉広, 服部弘之, 田中明, 穂積直裕, 小林和人

    人工臓器 35 (2) S121-S121 2006/10

  216. IVUSにおけるAttenuation Imagingの開発

    西條芳文, 田中明, サントス・フィロ・エスメラルド・ドス, 秋野能久, 花立安志, 山家智之

    Journal of Cardiology 48 (Suppl.I) 352-352 2006/09

  217. アロマによる自律神経活動と脳活動 Peer-reviewed

    段旭東, 田代学, 呉迪, 山家智之, 仁田新一, 伊藤正敏

    Journal of International Society of Life Information Science 24 (2) 383-395 2006/09

  218. バーチャル刺激による生理的影響と心理スケーリングとの関連 Peer-reviewed

    段旭東, 洪蘭, 田代学, 呉迪, 山家智之, 仁田新一, 伊藤正敏

    Journal of International Society of Life Information Science 24 (2) 343-354 2006/09

  219. ナノテクノロジーを応用した癌を治療する蠕動運動消化管ステント Invited

    山家智之

    日本消化器外科学会雑誌 39 (7) 907-907 2006/07

  220. Evaluation of cardiac function based on ventricular pressure-volume relationships during assistance with a rotary blood pump. Peer-reviewed

    Ogawa Daisuke, Tanaka Akira, Abe Ken-ichi, Olegario Paul, Kasahara Koichiro, Shiraishi Yasuyuki, Sekine Kazumitsu, Yambe Tomoyuki, Nitta Shin-ichi, Yoshizawa Makoto

    Conf Proc IEEE Eng Med Biol Soc 1 5378-5381 2006/04

    DOI: 10.1109/IEMBS.2006.260079  

  221. 動脈系のスティッフネスと心理傾向スケーリング

    山家智之

    自律神経 43 (2) 148-148 2006/04

  222. 脳内酸素ヘモグロビン及び自律神経機能の温水浴による変化 Peer-reviewed

    段旭東, 沙樹偉, 田代学, 呉迪, 山家智之, 王慶田, 仁田新一, 伊藤正敏

    Journal of International Society of Life Information Science 24 (1) 126-135 2006/03

  223. Comparative analysis of cardio-ankle vascular index between Japanese and Russians Peer-reviewed

    Hongjian Liu, Yoshifumi Saijo, Xiumin Zhang, Yasuyuki Shiraishi, Kazumitsu Sekine, Mitsuya Maruyama, Yori A. Kovalev, Irina A. Milyagina, Viktor A. Milygin, Tomoyuki Yambe

    FUTURE MEDICAL ENGINEERING BASED ON BIONANOTECHNOLOGY, PROCEEDINGS 411-+ 2006

    Publisher: WORLD SCIENTIFIC PUBL CO PTE LTD

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    Cardiovascular mortality in Russia has become the highest in the world. The Japanese are enjoying long lives, and the mortality caused by cardiovascular diseases has thus far remained at lower levels than that in Russia. Cardio-ankle vascular index (CAVI) is a new index of arteriosclerosis, a known independent risk factor for cardiovascular disease. In this study, we focused on CAVI obtained from Japanese and Russians, and compared their respective cardiovascular risks. We evaluated CAVI in 221 Japanese and 231 Russian healthy subjects. The CAVI was measured by using a CAVI device (CAVI-Vasera VS-1000; Fukuda Denshi, Tokyo, Japan). The CAVI showed a positive correlation with age in both Japanese and Russians. The CAVI in Russians was significantly higher than that obtained in Japanese in all three groups categorized by age (under 39 year-old, 40-59 year-old, and 60-year-old). Body mass index and mean blood pressure in Russians also showed higher values than those of Japanese in all three groups. Our results suggest that arteriosclerosis might be promoted earlier and faster in Russians, and Russians have a higher risk of cardiovascular disease related to arteriosclerosis than Japanese. This might be associated with the differences in their lifestyles.

  224. 637 Blood Flow Simulation Integrated with Ultrasonic Measurement : 6^<th> Report : Three-Dimensional Unsteady Blood Flow Simulation

    FUNAMOTO Kenichi, HAYASE Toshiyuki, SAIJO Yoshifumi, YAMBE Tomoyuki

    The proceedings of the JSME annual meeting 2006 195-196 2006

    Publisher: The Japan Society of Mechanical Engineers

    DOI: 10.1299/jsmemecjo.2006.5.0_195  

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    Development and progress of circulatory diseases are closely related to the hemodynamics in the blood vessel. However, detailed and accurate information of blood flow field has yet to be obtained due to the limitations both in measurement and numerical simulation. Hence, we have proposed the Ultrasonic-Measurement-Integrated (UMI) simulation. In this method, feedback signals derived from the difference between measured and computed Doppler velocities are fed back to the numerical simulation. The transient and steady characteristics of the UMI simulation have been revealed. In this paper, we performed the numerical experiment aiming at the reproduction of the three-dimensional unsteady flow field. As the result, the application of the feedback in the UMI simulation made the computational results converge and trace to the model of real blood flow.

  225. S-14 超音波による心臓・血管の中の流れの医工学的解析(特別企画II(要望演題5) 逆流性疾患・閉塞性疾患・拡張性疾患に対する治療戦略-管と流れと-,第43回 日本小児外科学会総会)

    西條 芳文, 白石 泰之, 関根 一光, 山家 智之, 田中 元直, 田林 晄一, 早瀬 敏幸, 船本 健一, 大槻 茂雄, 菅原 重生

    日本小児外科学会雑誌 42 (3) 355-355 2006

    Publisher: 特定非営利活動法人 日本小児外科学会

    DOI: 10.11164/jjsps.42.3_355_2  

  226. Preliminary study on the functional reproduction of an artificial myocardium using covalent shape memory alloy fibre based on control engineering Peer-reviewed

    Yasuyuki Shiraishi, Tomoyuki Yambe, Kazumitsu Sekine, Yoshifumi Saijo, Satosni Konno, Shin-Ichi Nitta, Qingtian Wang, Hongjian Liu, Masaru Higa, Daisuke Ogawa, Akira Tanaka, Makoto Yoshizawa, Yasuyuki Kakubari, Hidekazu Miura, Fumihiro Sato, Hidetoshi Matsuki, Shinji Itoh, Akinori Kamoda, Ryo Sakata, Yumiko Wada, Miyuki Uematsu, Youngkwang Park, Takashi Tanaka, Mitsuo Umezu, Tetsuo Fujimoto, Noriyasu Masumoto, Hiroshi Sasada, Koichi Tabayashi, Eiji Okamoto, Dai Homma

    2006 SICE-ICASE International Joint Conference 1734-1737 2006

    DOI: 10.1109/SICE.2006.315627  

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    The authors have been developing an artificial myocardium using a sophisticated covalent shape memory alloy fibre, which is capable of assisting natural cardiac contraction from the outside of the ventricular wall. We applied engineering method based on robotics control and constructed the artificial myocardial assist system which might be able to regulate derangement and regenerative tensile force on the surface of heart. In this study, a design to surround the total heart has been established in order to refrain from the stress concentration by the mechanical assistance, and the hemodynamic performance of the artificial myocardial assist system were examined in a mock circulatory system as well as on animal experiments using goats. Basic characteristics of the shape memory alloy fibre unit were examined and the displacement control could be achieved under the condition of the different external temperature by feedback using the PID control. And also the increase of the external work of the goats left ventricular pressure-volume relationship were obtained by the assistance using an artificial myocardium with parallel-linked configuration, and therefore it was indicated that the effective ventricular mechanical support could be performed by the device. © 2006 ICASE.

  227. Autonomic nervous activity revealed by a new physiological index rho(max) based on cross-correlation between mayer-wave components of blood pressure and heart rate Peer-reviewed

    Akira Tanaka, Norihiro Sugita, Makoto Yoshizawa, Yasuyuki Shiraishi, Tomoyuki Yambe, Shin-Ichi Nitta

    2006 SICE-ICASE INTERNATIONAL JOINT CONFERENCE, VOLS 1-13 4352-+ 2006

    Publisher: IEEE

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    The authors have proposed a new physiological index rho(max) which is the maximum cross-correlation coefficient between blood pressure and heart rate whose frequency components are limited to the Mayer wave-band (0.04-0.15Hz). The advantages of this index are small individual difference and high reproducibility compared with other physiological indices which are calculated independently single cardiovascular measurements. The previous study showed that the index rho(max) is possible to assess visually-induced motion sickness. However, the relation between the proposed index and autonomic nervous activity has not been clarified yet. In this study, the change in rho(max) during sympathetic or parasympathetic blockage has been investigated in comparison with conventional indices in an animal experiment. The results have indicated that rho(max) does not have information on parasympathetic nerve activity but sympathetic one.

  228. Method to evaluate the physiological effects of visual stimulation using finger photoplethysmography Peer-reviewed

    Makoto Abe, Makoto Yoshizawa, Norihiro Sugita, Akira Tanaka, Shigeru Chiba, Tomoyuki Yambe, Shin-Ichi Nitta

    FUTURE MEDICAL ENGINEERING BASED ON BIONANOTECHNOLOGY, PROCEEDINGS 893-+ 2006

    Publisher: WORLD SCIENTIFIC PUBL CO PTE LTD

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    The human watching moving images displayed on a wide-field display or a screen sometimes suffers from visually-induced motion sickness (VIMS) that induces symptoms related to the autonomic nervous system such as nausea, vomiting and dizziness. The previous study indicated that the maximum cross-correlation coefficient (P-) between blood pressure variability (BPV) and heart rate variability (HRV) whose frequency components are limited to the neighborhood of 0.1Hz is a useful index to evaluate the effects of VIMS on humans [1]. The present study has proposed a new method for obtaining rho(max) with measurement of neither continuous blood pressure nor ECG but using only finger photoplethysmography. The adequacy of the proposed method was evaluated on the basis of comparison with the conventional method. An experiment in which multiple subjects were simultaneously watching the same swaying video image was carried out. The experimental result has shown that the proposed method worked successfully as well as the conventional method.

  229. A System for Tissue Characterization and Quantification of Calcium Regions in Intravascular Ultrasound Peer-reviewed

    E. Santos Filho, Y. Saijo, T. Yambe, A. Tanaka, I. Iwamoto, S. Li, M. Yoshizawa

    2006 IEEE ULTRASONICS SYMPOSIUM, VOLS 1-5, PROCEEDINGS 1294-+ 2006

    Publisher: IEEE

    ISSN:1051-0117

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    This paper presents a combination of signal processing and image processing techniques for automatic segmentation and characterization of intravascular ultrasound images. This system is comprised of two modules, the tissue characterization module and the calcium quantification module. The tissue characterization module is based on classification of RF signal performed by a self-organizing map (SOM) previously trained. The calcium quantification module, using the image generated by the envelop of the RF signal, performs an adaptive thresholding based on the Otsu's method. The thresholding process is followed by the analysis of the acoustic shadow regime of the input image which permits to distinguish calcification regions from other small bright regions that, usually, still remain in the image after the thresholding processing.

  230. Simulation of atrial wall suction in a continuous flow total artificial heart model Peer-reviewed

    Paul S. Olegario, Makoto Yoshizawa, Akira Tanaka, Daisuke Ogawa, Yasuyuki Shiraishi, Tomoyuki Yambe, Shin-ichi Nitta

    2006 SICE-ICASE INTERNATIONAL JOINT CONFERENCE, VOLS 1-13 5266-+ 2006

    Publisher: IEEE

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    An existing mathematical model of the cardiovascular system was modified by replacing the ventricles of the natural heart with two rotary blood pumps to investigate the problem of atrial wall suction in a continuous flow total artificial heart system and provide preliminary data for the implementation of an anti-suction control algorithm with quicker response. The responses of left atrial pressure to changes in right pump output were investigated through computer simulations using the modified model. The results were then compared with actual data from a prior acute animal experiment with a healthy mature goat performed to obtain data on pulmonary circulation dynamics and to determine the conditions that lead to atrial wall suction. The simulation results showed significant agreement with the annual experiment data with regards to left atrial pressure response to changes in right pump speed. Atrial wall suction was also successfully simulated using this model.

  231. Evaluation of the hemodynamic parameters during circulatory assistance using an electro-hydraulic artificial myocardium system Peer-reviewed

    Qingtian Wang, Tomoyuki Yambe, Yasuyuki Shiraishi, Kazumitsu Sekine, Yoshifumi Saijo, Shin-Ichi Nitta, Makoto Yoshizawa, Mitsuo Umezu, Kouichi Tabayashi

    FUTURE MEDICAL ENGINEERING BASED ON BIONANOTECHNOLOGY, PROCEEDINGS 557-+ 2006

    Publisher: WORLD SCIENTIFIC PUBL CO PTE LTD

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    Artificial heart and ventricular assist devices were widely used in clinical as a therapy method to assist the severe heart failure patients. Unfortunately direct contact between the device and the patient's blood, thromboembolic events, the need for anticoagulation and infections contribute significantly to complication and mortality. Compressing the dysfunctional heart from its epicardial surface, non-blood contacting method of direct mechanical ventricular actuator compression system could provide ventricular support, pulsatile blood flow and avoid the interactions between blood and surface of artificial assistance system. We have developed an ElectroHydraulic Artificial Myocardial (EHAM) assist system that might be assist the heart muscle contraction. The purpose of this study was to determine if the EHAM system efficiency to hemodynamic parameters and myocardial tissue perfusion during its compressing in acute animal experiment. Eight adult goats were performed as acute experiments. Hemodynamic parameters were continuous monitored including ECG, aortic blood pressure, left ventricular pressure and pulmonary artery pressure. Myocardial tissue perfusion was measured by using Omega flow laser fiber attaching on the surface of the heart. The results showed that all the animals achieved significant increasing the blood pressure, pulmonary artery flow and myocardial tissue perfusion during the EHAM compressing compared with non-driving (pre-assisted) mode. In conclusions: EHAM system devices can effectively improves the myocardial tissue perfusion and increases the pressure thus having a potential for failing cardiac treatment.

  232. 左心室形成術における切除線決定のための診断法に関する基礎的検討 Peer-reviewed

    植松美幸, 白石泰之, 関根一光, 山家智之, 西條芳文, 安藤隼人, 朴栄光, 武田朴, 岩崎清隆, 梅津光生

    生体医工学 43 (4) 653-660 2005/12

    DOI: 10.11239/jsmbe.43.653  

  233. 【情報化社会における脳】 脳と心による心臓の制御 Peer-reviewed

    吉澤誠, 田中明, ポール・オレガリオ, 小川大祐, 阿部健一, 山家智之, 仁田新一

    Brain Medical 17 (4) 323-331 2005/12

  234. 【先駆的医工学と循環器】 機械的補助循環 Invited Peer-reviewed

    山家智之

    循環器科 58 (6) 566-570 2005/12

  235. 音楽刺激が自律神経に及ぼす影響 Peer-reviewed

    大久典子, 吉田克己, 山家智之, 賀来満夫

    自律神経 42 (3) 265-269 2005/06

  236. 人工臓器における基礎研究 人工内臓のためのナノテクノロジー

    山家智之

    医工学治療 17 (Suppl.) 126-126 2005/05

  237. Sound speed scanning acoustic microscopy for biomedical applications. Peer-reviewed

    Saijo Yoshifumi, Sasaki Hidehiko, Hozumi Naohiro, Kobayashi Kazuto, Tanaka Motonao, Yambe Tomoyuki

    Technol Health Care 13 (4) 261-267 2005/04

  238. Fundamental study of ultrasonic-measurement-integrated simulation of real blood flow in the aorta Peer-reviewed

    K Funamoto, T Hayase, A Shirai, Y Saijo, T Yambe

    ANNALS OF BIOMEDICAL ENGINEERING 33 (4) 415-428 2005/04

    Publisher: SPRINGER

    DOI: 10.1007/s10439-005-2495-2  

    ISSN:0090-6964

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    Acquisition of detailed information on the velocity and pressure fields of the blood flow is essential to achieve accurate diagnosis or treatment for serious circulatory diseases such as aortic aneurysms. A possible way to obtain such information is integration of numerical simulation and color Doppler ultrasonography in the framework of a flow observer. This methodology, namely, Ultrasonic-Measurement-Integrated (UMI) Simulation, consists of the following processes. At each time step of numerical simulation, the difference between the measurable output signal and the signal indicated by numerical simulation is evaluated. Feedback signals are generated from the difference, and numerical simulation is updated applying the feedback signal to compensate for the difference. This paper deals with a numerical study on the fundamental characteristics of UMI simulation using a simple two-dimensional model problem for the blood flow in an aorta with an aneurysm. The effect of the number of feedback points and the feedback formula are investigated systematically. It is revealed that the result of UMI simulation in the feedback domain rapidly converges to the standard solution, even with usually inevitable incorrect upstream boundary conditions. Finally, an example of UMI simulation with feedback from real color Doppler measurement also shows a good agreement with measurement.

  239. Development of an Artificial Myocardium using a Covalent Shape-memory Alloy Fiber and its Cardiovascular Diagnostic Response. Peer-reviewed

    Shiraishi Y, Yambe T, Sekine K, Saijo Y, Wang Q, Liu H, Nitta S, Konno S, Masumoto N, Nagatoshi J, Itoh S, Park Y, Uematsu M, Umezu M, Ogawa D, Olegario P, Sato F, Yoshizawa M, Tanaka A, Tabayashi K, Sasada H, Fujimoto T, Homma D, Higa M, Hori Y

    Conf Proc IEEE Eng Med Biol Soc 1 (1) 406-408 2005/04

    DOI: 10.1109/IEMBS.2005.1616431  

  240. Artificial esophagus with peristaltic movement Peer-reviewed

    M Watanabe, K Sekine, Y Hori, Y Shiraishi, T Maeda, D Honma, G Miyata, Y Saijo, T Yambe

    ASAIO JOURNAL 51 (2) 158-161 2005/03

    Publisher: LIPPINCOTT WILLIAMS & WILKINS

    DOI: 10.1097/01.MAT.0000154644.44891.F1  

    ISSN:1058-2916

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    In this study, we have developed an artificial esophagus simulating peristaltic movement with the use of a nickel-titanium shape memory alloy (NiTi-SMA) actuator. Serial pairs of NiTi-SMAs were placed around a Gore-Tex vascular graft in a helical position such that they obliterated the lumen of the vessel when they contracted. In an animal experiment using a goat, the cervical esophagus was resected over a length of approximately 20 cm. The artificial esophagus was anastomosed with the remaining cervical esophagus. When a direct current of 500 mA at 5 V was applied to the NiTi-SMAs, the first pair of the NiTi-SMA contracted. The following pairs of the NiTi-SMAs contracted consecutively. The entire contraction of the artificial esophagus was similar to the esophageal peristaltic movement observed by x-ray examination in humans. The results showed the possibility that the artificial esophagus could function as an artificial esophagus having peristaltic movement.

  241. 1108 Blood Flow Simulation Integrated with Ultrasonic Measurement : 4^<th> Report: Improvement of Accuracy of Computational Hemodynamics

    FUNAMOTO Kenichi, HAYASE Toshiyuki, SAIJO Yoshifumi, YAMBE Tomoyuki

    The proceedings of the JSME annual meeting 2005 89-90 2005

    Publisher: The Japan Society of Mechanical Engineers

    DOI: 10.1299/jsmemecjo.2005.5.0_89  

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    Hemodynamics plays an important role in the development, progress and rupture of aneurysms, and therefore, is essential for advanced diagnosis. However, existing methodologies have yet to provide detailed and accurate information of blood flow field due to their individual limitations. As a solution to the problem, we have proposed Ultrasonic-Measurement-Integrated (UMI) simulation. In this method, feedback signals derived from the difference between measured Doppler velocity and the calculated one by numerical simulation are fed back to the numerical simulation. In this paper, we validate the efficacy of three-dimensional UMI simulation by the numerical analysis with various irradiation methods of ultrasonic beam. As the result, UMI simulation improves computational accuracy and enables us to obtain more accurate information of blood flow field including wall shear stress.

  242. 410 Study of Three-dimensional Feedback Law for Ultrasonic-Measurement-Integrated Simulation of Blood Flow in the Aorta

    FUNAMOTO Kenichi, HAYASE Toshiyuki, SAIJO Yoshifumi, YAMBE Tomoyuki

    Proceedings of the JSME Bioengineering Conference and Seminar 2004 151-152 2005

    Publisher: The Japan Society of Mechanical Engineers

    DOI: 10.1299/jsmebs.2004.17.0_151  

  243. Evaluation of the effect of visual stimulation on humans by simultaneous experiment with multiple subjects Peer-reviewed

    Norihiro Sugita, Makoto Yoshizawa, Aldra Tanaka, Ken-ichi Abe, Shigeru Chiba, Tomoyuki Yambe, Shin-ichi Nitta

    2005 27TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY, VOLS 1-7 5572-5575 2005

    Publisher: IEEE

    ISSN:1094-687X

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    To evaluate the biological effects of visual stimulation on multiple subjects watching a same image, a more compact and low-cost device measuring both ECG and photo-plethysmogram was developed. On the basis of these physiological parameters, the maximum cross-correlation coefficient, rho(max), from pulse wave transmission time to heart rate could be calculated. This index reflects the activity of the autonomic nervous system and is considered as a good index for evaluating the effect of visual stimulation on humans. The result of simultaneous experiment with 6 subjects watching a video image taken by an intentionally swaying handy camera has shown that rho(max) of almost all subjects decreased in the latter part of the video image and that p(max) of the subjects who felt motion sickness strongly decreased after watching the video image at a time.

  244. Detection and correction of aliasing in ultrasonic measurement of blood flows with Ultrasonic-Measurement-Integrated simulation Peer-reviewed

    Kenichi Funamoto, Toshiyuki Hayase, Yoshifumi Saijo, Tomoyuki Yambe

    Technology and Health Care 13 (4) 331-344 2005

    ISSN:0928-7329

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    Detailed information of real blood flows is essential to develop an accurate diagnosis or treatment for serious circulatory diseases such as aortic aneurysms. Ultrasonic-Measurement-Integrated (UMI) simulation, in which feedback signals from the ultrasonic measurement make the simulation converge to the real blood flow, is a key to solving this problem. However, aliasing in the ultrasonic blood velocity measurement causes UMI simulation to converge to an erroneous result. In this paper, we have investigated the detection and the correction of aliasing in UMI simulation. The artificial force in the feedback of UMI simulation can be used as an index to detect the aliasing. We have proposed two ways for the correction of the aliasing. Correction A, in which measurement velocity is replaced with the computational one at the monitoring point where the aliasing is detected, substantially improves the accuracy of UMI simulation. Correction B, in which measurement velocity is replaced with an estimated Doppler velocity, can provide exactly the same result as that of UMI simulation using the nonaliased standard solution. Although correction B gives the most accurate result, correction A seems more robust and, therefore, a beneficial choice considering the other artifacts in the measurement. © 2005 - IOS Press and the authors. All rights reserved.

  245. Non-blood contacting electro-hydraulic artificial myocardium (EHAM) improves the myocardial tissue perfusion Peer-reviewed

    Qingtian Wang, Tomoyuki Yambe, Yasuyuki Shiraishi, Xudong Duan, Makoto Yoshizawa, Kouichi Tabayashi, Shinichi Nitta, Mitsuo Umezu

    Technology and Health Care 13 (4) 229-234 2005

    ISSN:0928-7329

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    Artificial heart (AH) and ventricular assist devices (VAD) are widely used in the clinical setting to assist severe heart failure patients. The concept of direct cardiac compression (DCC) has been in use for several decades and has advantages over intravascular VAD. The process involves compressing the dysfunctional heart from its epicardial surface to avoid the thromboembolic events and decrease the complications and mortality. An Electro-hydraulic Artificial Myocardium (EHAM) system was designed and fabricated by Tohoku University. This system may assist cardiac contraction and create pulsatile blood flow. The aim of this study was to clearly define the hemodynamic efficiency of the EHAM system in myocardial tissue perfusion during its application in acute animal experiment. Eight healthy adult goats were used left lateral thoracotomy was performed and the chest was opened by the resection of the 4th and 5th ribs. Hemodynamic parameters including ECG, blood pressure and cardiac output were continuously monitored. Myocardial tissue perfusion was measured by using Omega flow laser fiber attached to the surface of the heart. During the EHAM compression, and increase in blood pressure and myocardial tissue perfusion was observed in all animals when compared with pre-assisted mode. To conclude, EHAM effectively improves myocardial tissue perfusion and increases the pressure on the initiation of direct cardiac compression immediately. Thus it can be a potentially valuable adjunct in the management of severe heart failure. © 2005 - IOS Press and the authors. All rights reserved.

  246. Comparison of heart rate variability and stroke volume variability Peer-reviewed

    H Liu, T Yambe, H Sasada, S Nanka, A Tanaka, R Nagatomi, S Nitta

    AUTONOMIC NEUROSCIENCE-BASIC & CLINICAL 116 (1-2) 69-75 2004/11

    Publisher: ELSEVIER SCIENCE BV

    DOI: 10.1016/j.autneu.2004.09.003  

    ISSN:1566-0702

    eISSN:1872-7484

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    In order to compare the heart rate variability (HRV) and stroke volume variability (SVV), supine electrocardiographic (ECG) and the time series data of left ventricular (LV) volume recordings were taken in 12 healthy adult male volunteers. The low frequency (LF) and high frequency (HF) peaks of HRV and SVV were evaluated quantitatively by power spectral analysis. The fractal dimension (FD) of the time series data was analyzed by the box-counting method. A LF peak around 0.1 Hz and a HF peak around 0.3 Hz were as clearly observed in the SVV spectrum as in the HRV spectrum. The LF/HF ratio in SVV was significantly lower than that in HRV, while the FD was significantly higher in SVV than in HRV. No significant correlation of HF, LF or FD was observed between HRV and SW Our results indicate that SVV provides different information about the activity of the autonomic nervous system than HRV (C) 2004 Elsevier B.V. All rights reserved.

  247. Addition of rhythm to non-pulsatile circulation. Peer-reviewed

    Yambe Tomoyuki, Sekine Kazumitsu, Shiraishi Yasuyuki, Watanabe Makoto, Shibata Mune-ichi, Yamaguchi Tasuku, Quintian Wang, Duan Xudong, Jian Liu Hong, Yoshizawa Makoto, Tanaka Akira, Matsuki Hidetoshi, Sato Fumihiro, Haga You-ichi, Esashi Masayoshi, Tabayashi Kouichi, Mitamura Yoshinori, Sasada Hiroshi, Sato Eimei, Saijo Yoshifumi, Nitta Shin-ichi

    Biomed Pharmacother 58 Suppl 1 S145-9 2004/10

    DOI: 10.1016/S0753-3322(04)80024-6  

  248. Brachio-ankle pulse wave velocity and cardio-ankle vascular index (CAVI). Peer-reviewed

    Yambe Tomoyuki, Yoshizawa Makoto, Saijo Yoshifumi, Yamaguchi Tasuku, Shibata Muneichi, Konno Satoshi, Nitta Shinichi, Kuwayama Takashi

    Biomed Pharmacother 58 Suppl 1 S95-8 2004/10

    DOI: 10.1016/S0753-3322(04)80015-5  

  249. A Japanese-Russian collaborative study on aging and atherosclerosis. Peer-reviewed

    Yambe Tomoyuki, Kovalev Yuri A, Milyagina Irina A, Milyagin Viktor A, Shiraishi Yasuyuki, Yoshizawa Makoto, Saijo Yoshifumi, Yamaguchi Tasuku, Shibata Mune-ichi, Nitta Shinichi

    Biomed Pharmacother 58 Suppl 1 S91-4 2004/10

    DOI: 10.1016/S0753-3322(04)80014-3  

  250. Development of an implantable undulation type ventricular assist device for control of organ circulation Peer-reviewed

    T Yambe, Y Abe, K Imachi, Y Shiraishi, MI Shibata, T Yamaguchi, QT Wang, XD Duan, HJ Liu, M Yoshizawa, A Tanaka, H Matsuki, F Sato, YI Haga, M Esashi, K Tabayashi, Y Mitamura, H Sasada, M Umezu, T Matsuda, SI Nitta

    ARTIFICIAL ORGANS 28 (10) 940-944 2004/10

    Publisher: BLACKWELL PUBLISHING INC

    DOI: 10.1111/j.1525-1594.2004.07382.x  

    ISSN:0160-564X

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    It is well known that a rotary blood pump (RP) is effective as a small ventricular assist device (VAD). It might be still more effective if pulsation was available. The undulation pump (UP), which is a type of small RP, can also produce pulsation. In Japan, a development project for an implantable type UP ventricular assist device (UPVAD) is now advanced. Six universities and some companies together have been in charge of the development project for 5 years. In this study, the influence which the UP under development has on circulation in internal organs was investigated. Goats with the same weight as an average Asian person were used for the experiment. The left chest cavity was opened after resection of the fourth rib and the heart was approached. A cannula was inserted in the left ventricle from the apex. An outflow cannula was inserted into the left descending aorta. Heart muscle was excised using a newly developed puncher. The UPVAD was implanted using a left-heart bypass system. The myocardial blood flow, carotid arterial blood flow, and the kidney blood flow were recorded together with an electrocardiogram, blood pressure, and the flow rate. In these animal experiments, the blood circulation dynamic state was stabilized and sufficient support of the left heart was observed. Myocardial blood flow, carotid arterial flow, and a kidney blood flow increase resulting from UPVAD support was observed. Often the problem of multiple organ failure is important at the time of clinical application of a ventricular assist device. Assisting circulation to internal organs is important for prevention of multiple organ failure. It was concluded that the UPVAD might be useful for prevention of multiple organ failure.

  251. Component engineering for an implantable system Peer-reviewed

    QT Wang, T Yambe, Y Shiraishi, M Esashi, Y Haga, M Yoshizawa, F Sato, H Matsuki, K Imachi, Y Abe, H Sasada, S Nitta

    ARTIFICIAL ORGANS 28 (10) 869-873 2004/10

    Publisher: BLACKWELL PUBLISHING INC

    DOI: 10.1111/j.1525-1594.2004.07383.x  

    ISSN:0160-564X

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    Component engineering is important for the development of implantable-type rotary blood pumps (RP). The authors are conducting elementary development of an implantable artificial heart. A sensor system detects information in the living body. An automatic control system performs the drive control. Energy is provided by a transcutaneous energy transmission system (TETS). Various artificial hearts are being created. Miniaturization resulting from an increase in operating frequency is planned. A vibrating flow pump (VFP) has a reduced size of pumping chamber because of the high-speed reciprocating movement. Undulation pump ventricular assist devices (UPVAD) are small, lightweight rotary pumps. VFPs are useful in the medical treatment of multiple organ failure (MOF). UPVADs are planned to be permanent-use RPs. The purposes of these two artificial hearts differ, although they have a common component. The authors are developing TETS by using amorphous fibers, making efficient power transmission possible. Control information input from a micro or nano sensor is realized. A control algorithm has been developed and baroreflex control has been successful. Artificial heart development, fully exploiting component engineering, continues.

  252. An artificial myocardium assist system: Electrohydraulic ventricular actuation improves myocardial tissue perfusion in goats Peer-reviewed

    QT Wang, T Yambe, Y Shiraishi, XD Duan, S Nitta, K Tabayashi, M Umezu

    ARTIFICIAL ORGANS 28 (9) 853-857 2004/09

    Publisher: BLACKWELL PUBLISHING INC

    DOI: 10.1111/j.1525-1594.2004.0004.x  

    ISSN:0160-564X

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    Artificial hearts and ventricular assist devices have been widely used clinically to assist patients with severe heart failure. Unfortunately, direct contact between the device and the patient's blood leads to thromboembolic events, and then the need for anticoagulation and infections contribute significantly to complication and mortality. Compressing the dysfunctional heart from its epicardial surface, a nonblood-contacting method of direct mechanical ventricular actuation could provide ventricular support, pulsatile blood flow, and avoid interactions between blood and the surface of the artificial assistance system. An ElectroHydraulic Artificial Myocardial (EHAM) assist system that might assist heart muscle contraction has been developed. The purpose of this study is to determine the efficiency of the EHAM system in perfusing myocardial tissue in an acute animal experiment. Method: Healthy adult goats (n = 8) were used in acute animal experiments. A left lateral thoracotomy was done and the chest was opened through the 4th and 5th rib resection. Hemodynamic parameters were continuously monitored including ECG, aortic blood pressure, left ventricular pressure, and pulmonary artery pressure. Myocardial tissue perfusion was measured by using an Omega flow laser fiber attached on the surface of the heart. Results: All the animals achieved significantly increased blood pressure, pulmonary artery flow, and myocardial tissue perfusion during the EHAM compression compared with the nondriving (pre-assisted) mode. Conclusions: The EHAM system can effectively improve myocardial tissue perfusion and increase blood pressure thus demonstrating a potential for treating failing cardiac performance.

  253. 香り刺激による心拍変動と脳神経細胞の酸素代謝 Peer-reviewed

    大久典子, 山家智之, 吉田克己

    自律神経 41 (4) 439-443 2004/08

  254. Functional evaluation of an artificial anal sphincter using shape memory alloys Peer-reviewed

    Y Luo, T Takagi, T Okuyama, S Amae, M Wada, K Nishi, T Kamiyama, T Yambe, H Matsuki

    ASAIO JOURNAL 50 (4) 338-343 2004/07

    Publisher: LIPPINCOTT WILLIAMS & WILKINS

    DOI: 10.1097/01.MAT.0000131819.07741.EF  

    ISSN:1058-2916

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    This article describes an implantable artificial anal sphincter using shape memory alloys and its in vivo assessment in porcine models. The new design was developed as a low invasive prosthesis with a simple structure to solve the problem of severe fecal incontinence in patients with hypoplastic sphincters or without anal sphincters and especially for ostomates. The artificial anal sphincter consists of two shape memory alloy (SMA) plates as the main functional parts to perform two basic functions when the SMA artificial sphincter is fitted around intestines (i.e., an occlusion at body temperature and an opening function on heating). Our previous assessments with short-term animal experiments revealed promising properties with the occlusion function of the device, although some complications, such as overpressure induced ischemia, heat burn, and infections, remained. This article addresses the concerns related to the practical use of the device, the power supplement to drive the actuator, and overheating protection of the device inside bodies. Results of chronic animal experiments of up to 4 weeks suggested great potential for the improved device.

  255. 補助循環

    下野 高嗣, 白石 泰之, 田岡 誠, 有賀 睦, 山家 智之, 枝 州浩, 秦 光賢, 横井 健人

    人工臓器 33 (2) s193-s196 2004

    Publisher: JAPANESE SOCIETY FOR ARTIFICIAL ORGANS

    DOI: 10.11392/jsao1972.33.2Supplement_s193  

    ISSN:0300-0818

  256. Assessment of emotional reaction induced by visual stimulation based on cross-correlation between pulse wave transmission time and heart rate in the Mayer wave-band Peer-reviewed

    M Yoshizawa, N Sugita, A Tanaka, T Masuda, K Abe, S Chiba, T Yambe, S Nitta

    PROCEEDINGS OF THE 26TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY, VOLS 1-7 26 2411-2414 2004

    Publisher: IEEE

    ISSN:1094-687X

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    Mayer wave (0.1Hz fluctuation) included in heart rate variability and blood pressure variability appears apparently in the resting state. On the other hand, it can be predicted that a strong emotional reaction may affect the relationship between these variabilities. This prediction suggests that the human emotional reaction can be quantified by the maximum correlation coefficient rho(max) between heart rate and blood pressure whose frequency components are limited to the Mayer wave-band. However, the conventional method of obtaining rho(max) needs a bulky and expensive device for measuring continuous blood pressure. In this study, a smaller and cheaper device for measuring pulse wave transmission time (PTT) has been developed. This paper has shown that the PTT can give rho(max) instead of blood pressure and that rho(max) obtained by the PTT may significantly reflect the emotional reaction on the basis of an experiment using nine healthy subjects with nine self-produced devices in which pictures were presented to the subjects to induce their emotional reactions.

  257. Control of continuous flow artificial heart using estimated flow rate and pressure head Peer-reviewed

    D Ogawa, M Yoshizawa, A Tanaka, P Olegario, T Hanaoka, Y Shiraishi, T Yambe, SI Nitta

    SICE 2004 ANNUAL CONFERENCE, VOLS 1-3 2099-2102 2004

    Publisher: SOC INSTRUMENT CONTROL ENGINEERS JAPAN

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    A total artificial heart (TAH) is not connected to the central nervous system, and then the TAH system has to determine an adequate operation by itself. Pressure and flow rate are important indices for the decision, however, embedded pressure and How sensors tend to cause thrombus formation and their durability is insufficient. To avoid this problem, we studied the flow rate and pressure head estimation with rotational speed and supplied power using an ARX model. In this paper, we discuss about the TAH control system using the estimated value instead of the measured value. We had experiments to identify parameter of estimator and control flow rate using the estimated value instead of the measured value, in in vitro and in vivo. In the identification experiment, we could verify enough accuracy of estimator. In the control experiment, the control system was stable but a biased error between measured and estimated value was found.

  258. Dynamic response of the pulmonary circulation in a continuous flow artificial heart system Peer-reviewed

    PS Olegario, M Yoshizawa, A Tanaka, Y Shiraishi, D Ogawa, T Hanaoka, K Abe, T Yambe, S Nitta

    SICE 2004 ANNUAL CONFERENCE, VOLS 1-3 2225-2228 2004

    Publisher: SOC INSTRUMENT CONTROL ENGINEERS JAPAN

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    Pulmonary circulation dynamics is important when considering bi-ventricular assist devices (BiVAD) or total artificial heart (TAH) systems, and in investigating the mechanism of atrial suction in order to design better control algorithms. In this study, we investigated pulmonary circulation dynamics in a continuous flow artificial heart system by performing acute tests on a mature goat. By varying the right pump speed, we were able to observe the dynamic response of the left atrial pressure (LAP) and simulate conditions that result in atrial suction. We were able to measure the time constant of the LAP response to changes in right pump output in the TAR configuration. These results may prove useful in the design of a new mock circulatory system that incorporates the dynamics of the pulmonary circulation, and in the improvement of existing control algorithms to prevent atrial wall suction.

  259. Open-loop analysis of transfer characteristics from blood pressure to heart rate using an effectively total artificial heart Peer-reviewed

    A Tanaka, M Yoshizawa, K Abe, H Takeda, T Yambe, S Nitta, Y Abe, T Chinzei, K Imachi

    ARTIFICIAL ORGANS 28 (1) 109-114 2004/01

    Publisher: BLACKWELL PUBLISHING INC

    DOI: 10.1111/j.1525-1594.2004.06916.x  

    ISSN:0160-564X

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    It is desirable for the dynamic behavior of the drive rate of the artificial heart to be as similar as possible to that of the recipient's heart rate (HR) before implantation. This requires a model which can simulate the behavior of HR on the basis of only the information measured with the limited number of approvable implanted sensors. This article provides a linear time series model for explaining the behavior of HR only with aortic pressure and right atrial pressure. This could be obtained from open-loop analysis using a total artificial heart, which was introduced for measuring HR in vivo and for eliminating its effect on blood pressure. The model was identified in a goat equipped with a special biventricular assist device called the effectively total artificial heart (ETAH). The ETAH was introduced to make an open loop and awake situation in the animal with almost intact autonomic nerves, which could enhance the accuracy and reliability of the identification of the model. The adequacy of the proposed model was ascertained in several data sets measured in two goats, which were different from the data set used for identification. Most of the mean estimation errors were less than 3 beats/min and auto-correlation analysis showed approvable statistical appropriateness. However, it was clarified through comparison with the 1/R control method that the proposed model has a few problems still to be solved before its future implementation as an automatic controller of the TAH.

  260. Development of an implantable artificial anal sphincter using a shape memory alloy Peer-reviewed

    K Nishi, T Kamiyama, M Wada, S Amae, T Ishii, T Takagi, Y Luo, T Okuyama, T Yambe, Y Hayashi, R Ohi

    JOURNAL OF PEDIATRIC SURGERY 39 (1) 69-72 2004/01

    Publisher: W B SAUNDERS CO

    DOI: 10.1016/S0022-3468(03)00701-2  

    ISSN:0022-3468

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    Background/Purpose: The authors created a new artificial anal sphincter using a shape memory alloy (AS-SMA) to treat fecal incontinence and evaluated its validity. Methods: AS-SMA consists of 2 Ti-Ni plates to sandwich the intestine and generates a pressure of 55 mm Hg at its resting position. With the electric power supply, the 2 metals bend to form an almondlike shape making a maximum gap of 33 mm between each other at the temperature of 55degreesC. The device was attached to the colostomy in a piglet and was operated several times a day for 1 month. Fecal continence, bowel movements, and general condition of the piglet were recorded. After the experiment, tissue damage around the device was investigated. Results: Fecal continence was obtained while the device was in the resting position. When it was operated, bowel movements were observed. The bowel movements to operations ratio was 82:105 (78%). During the experiment, the animal had neither abdominal distension nor vomiting. At the autopsy, there was mild inflammation and shallow burns around the device. No compression injury was detected. Conclusions: AS-SMA achieved fecal continence of the colostomy. With reduction of the associated side effects, it would be a potential substitute for an impaired anal sphincter. (C) 2004 Elsevier Inc. All rights reserved.

  261. 【ユビキタス映像社会における健康と安全】 ユビキタス映像に対する自律神経反応と心理スケーリング Invited Peer-reviewed

    山家智之, 南家俊介, 洪蘭, 仁田新一

    BME 18 (1) 14-20 2004/01

    DOI: 10.11239/jsmbe1987.18.14  

  262. 【ユビキタス映像社会における健康と安全】 生理的パラメータの相互相関を用いた映像の生体影響評価法 Invited Peer-reviewed

    吉澤誠, 田中明, 杉田典大, 阿部健一, 山家智之, 仁田新一

    BME 18 (1) 8-13 2004/01

    Publisher: None

    DOI: 10.11239/jsmbe1987.18.8  

    ISSN:0913-7556

  263. Recording vagal nerve activity for the control of an artificial heart system Peer-reviewed

    T Yambe, SS Nanka, Y Shiraishi, A Tanaka, M Yoshizawa, K Abe, K Tabayashi, H Takeda, S Nitta

    ASAIO JOURNAL 49 (6) 698-700 2003/11

    Publisher: LIPPINCOTT WILLIAMS & WILKINS

    DOI: 10.1097/01.MAT.0000094193.21479.91  

    ISSN:1058-2916

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    Monitoring cardiovascular control system information is important in considering the quality of life (QOL) of patients with artificial hearts. Natural heart circulation is controlled by an autonomic nervous system. Therefore, it is desirable to record autonomic nerve activity for the control of artificial heart systems. We directly recorded vagal nerve activity in long-term animal experiments. Six healthy adult goats were anesthetized with halothane inhalation, and thoracotomy was performed with the fourth rib resection during mechanical ventilation. Arterial blood pressure and right and left atrial pressures were continuously monitored with an inserted catheter. Cardiac output was measured by an electromagnetic flow meter attached to the ascending aorta. After the chest was closed, an incision was made in the left neck, and the left vagal nerve was separated. Stainless steel electrodes were inserted into the vagal nerve and fixed by a plasticizer. After the incision was closed, the goats were transferred to a cage and extubated after waking. Vagal nerve activity was measured using hemodynamic parameters when the animals were awake. Our results show that clear observation of autonomic nerve discharge was made through this experimental system for over 1 month. The tonus of the vagal nerve was significantly altered before body motion with hemodynamic changes, suggesting the possibility of prediction. These results suggest that information from autonomic nerves may help to control implantable artificial hearts or ventricular assist devices.

  264. Artificial myocardium with an artificial baroreflex system using nano technology Peer-reviewed

    T Yambe, Y Shiraishi, M Yoshizawa, A Tanaka, K Abe, F Sato, H Matsuki, M Esashi, Y Haga, S Maruyama, T Takagi, Y Luo, E Okamoto, Y Kubo, M Osaka, S Nanka, Y Saijo, Y Mibiki, T Yamaguchi, M Shibata, S Nitta

    BIOMEDICINE & PHARMACOTHERAPY 57 122S-125S 2003/10

    Publisher: ELSEVIER FRANCE-EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER

    DOI: 10.1016/j.biopha.2003.08.016  

    ISSN:0753-3322

    eISSN:1950-6007

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    Where is the place which should be helped in a patient with congestive heart failure? The answer may be contraction of the heart. At Tohoku University, development research of "the artificial myocardium" has been conducted, using a ball screw type electromagnetic motor. Furthermore, super-miniaturization is being attempted at present. Thus, a system with shape memory alloy is being developed. The cooling speed problem was solved by the application of the Peltier element. A drive at a speed equal to that of a heartbeat was realized by the application of this system. At present, a ventricular assist device is used for patients waiting for a heart transplant in Japan. An air driven type system disturbs a patient's QOL remarkably because it is connected to the drive device. With our concept, energy is provided by using the electromagnetic force from outside of the body by the use of transcutaneous energy transmission system. Magnetic shielding by amorphous fibers was used at Tohoku University to improve the total efficiency. A natural heart can alter the cardiac output corresponding to the demand. Artificial internal organs must participate in the system of the living body, too. Tohoku University has developed a resistance based artificial heart control algorithm, which simulated a baroreflex system to cope with every demand. Nano level sensing equipment is now under development at Tohoku University. At present, development is being conducted aiming at an "intelligent artificial myocardium". (C) 2003 Editions scientifiques et medicales Elsevier SAS. All rights reserved.

  265. Can personality traits predict pathological responses to audiovisual stimulation? Peer-reviewed

    T Yambe, M Yoshizawa, S Fukudo, H Fukuda, R Kawashima, K Shizuka, S Nanka, A Tanaka, K Abe, T Shouji, M Hongo, K Tabayashi, S Nitta

    BIOMEDICINE & PHARMACOTHERAPY 57 83S-86S 2003/10

    Publisher: EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER

    DOI: 10.1016/j.biopha.2003.08.010  

    ISSN:0753-3322

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    The "Pockemon shock" is the most famous accident in the history of the broadcasting industry in Japan. Based on the experiences of this unfortunate accident from famous animation program "Pocket Monster", this study focused on the psychology and psychosomatics of the patients. A head-mounted display was used as the three-dimensional image presentation device and "Descent", a free software shooting game, was used as the software. Ten healthy adult male volunteers were used in this experiment after obtaining their informed consent. The oxygen metabolic change in the anterior lobe of the brain was measured by near infrared spectroscopy and recorded on an electrocardiogram. The mental scaling tendency of the object was analyzed using the type A behavior pattern and the hostility scaling. The Cook and Medley hostility (HO) scale from the Minnesota multiphasic personality inventory (MMPI) was also used in this experiment. From this scaling methodology, the paranoid scale, cynicism scale, lie scale, social support quality and social support quantity were calculated. All measured time series data were kept in the normal range, and no fatal arrhythmia or epilepsy were observed during experiments. In some cases, the brain oxygen metabolism may completely differ for the objects of Type A and Type B behavior patterns. On the whole, correlation did not become significant in type A scaling and hostility scaling. In a comparison of the percent changes of the HF in HRV with lie scaling, significant negative correlation was observed. The social support quantity was calculated from Cook and Medley, and significant negative correlations were observed with percent changes of LF/HF in HRV. The lie scale and social support quantity are opposite scaling. The sympathetic nervous system and parasympathetic nervous system have an opposite function also. Therefore, our results showed an interesting phenomenon, when considering the relationship between the autonomic function and the pathophysiological reaction to the audiovisual stimulations. As for the photo sensitive epilepsy, it was reported to be only 5-10% for ail patients. Therefore, 90% or more of the cause could not be determined in patients who started a morbid response. The results in this study suggest that the autonomic function was connected to the mental tendency of the objects. By examining such directivity, it is expected that subjects, which show morbid reaction to an audiovisual stimulation, can be screened beforehand. (C) 2003 Editions scientifiques et medicales Elsevier SAS. All rights reserved.

  266. 映像コンテンツによる視聴覚刺激が生体の自律神経機能に与える影響 Peer-reviewed

    段旭東, 王慶田, 山家智之, 仁田新一, 川島隆太

    Journal of International Society of Life Information Science 21 (2) 455-463 2003/09

  267. 「選択型統合講義」の実施とその成果・問題点について Peer-reviewed

    竹内和久, 山家智之, 飛松好子, 加賀谷豊, 石井誠一, 藤盛啓成, 佐藤譲, 大内憲明, 本郷道夫, 山田章吾

    医学教育 34 (Suppl.) 30-31 2003/07

  268. ナノテク集積人工心筋開発プロジェクト Invited Peer-reviewed

    山家智之, 白石泰之, 井口篤志, 田林晄一, 芳賀洋一, 江刺正喜, 吉澤誠, 田中明, 松木英敏, 佐藤文博, 川野恭之, 羅雲, 高木敏行, 早瀬敏幸, 圓山重直, 王慶田, 段旭東, 仁田新一, 岡本英治, 久保豊, 大坂元久, 梅津光生

    循環制御 24 (2) 111-117 2003/06

    ISSN:0389-1844

  269. 計算負荷における心拍変動と脳神経細胞の酸素代謝 Peer-reviewed

    大久典子, 鈴木真悠子, 佐々木春香, 山家智之, 吉田克己, 張替秀郎, 賀来満夫

    自律神経 40 (2) 166-169 2003/04

  270. Chaos attractors of ventricular elastance to evaluate cardiac performance Peer-reviewed

    T Yambe, M Yoshizawa, R Taira, A Tanaka, K Tabayashi, H Sasada, S Nitta

    ARTIFICIAL ORGANS 27 (1) 104-107 2003/01

    Publisher: BLACKWELL PUBLISHING INC

    DOI: 10.1046/j.1525-1594.2003.07182.x  

    ISSN:0160-564X

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    Quantitative evaluation of cardiac function is very important in the clinical application of a ventricular assist device. This article reports a new evaluating method of E max, which is the most reliable parameter to evaluate cardiac function. Fluctuation in the E max time series data was evaluated by the nonlinear mathematical analyzing method including chaos and fractal theory. Experimental goats were anesthetized with halothane inhalation, and left ventricular volume and pressure were measured with other hemodynamic parameters to evaluate E max during various drug administrations. E max was evaluated by two methods. One was the conventional pressure volume loop evaluation and the other was the parameter optimization method without left ventricular volume data. As a result, E max evaluated by the parameter optimization method correlated well with the E max with conventional PV curve. Furthermore, interesting results were obtained. There were rhythmical fluctuations in the E max time series data. By the methodology of Takens, E max time series data was embedded into the phase space and a strange attractor was observed. These results may be important when considering E max evaluation during left ventricular assistance.

  271. In vivo test of pressure head and flow rate estimation in a continuous-flow artificial heart Peer-reviewed

    A Tanaka, M Yoshizawa, K Abe, H Takeda, T Yambe, S Nitta

    ARTIFICIAL ORGANS 27 (1) 99-103 2003/01

    Publisher: BLACKWELL PUBLISHING INC

    DOI: 10.1046/j.1525-1594.2003.07175.x  

    ISSN:0160-564X

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    To avoid using sensors with low biocompatibility and low durability in implantable total artificial heart (TAH) systems, the authors previously proposed a new method for estimating instantaneous values of flow rate and pressure head on the basis of voltage, current, and rotational speed in a motor driven centrifugal pump. The previous in vitro experiments showed that the proposed estimator could automatically compensate for the effect of the change in blood viscosity on the estimation accuracy by employing two kinds of autoregressive exogenous models. In this study, validity and reliability of this estimation method were ascertained in an acute animal experiment. In the experiment, two centrifugal blood pumps were implanted into an adult goat as a total artificial heart. Results of estimation were compared with true values when blood viscosity was changed by injecting physiological saline. The results indicated that the system could successfully estimate pressure head by compensating the change of viscosity, although the estimation accuracy of the in vivo estimation was not so high as that of the previous in vitro tests.

  272. Outflow control for avoiding atrial suction in a continuous flow total artificial heart Peer-reviewed

    PS Olegario, M Yoshizawa, A Tanaka, K Abe, H Takeda, T Yambe, S Nitta

    ARTIFICIAL ORGANS 27 (1) 92-98 2003/01

    Publisher: BLACKWELL PUBLISHING INC

    DOI: 10.1046/j.1525-1594.2003.07185.x  

    ISSN:0160-564X

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    Continuous flow blood pumps, such as axial flow and centrifugal pumps, have been gaining interest as circulatory devices for total artificial hearts (TAHs) because of their smaller size and simpler structure compared to pulsatile pumps. However, continuous flow pumps are more prone to atrial wall suction than pulsatile pumps are. Sudden increases in flow rate to meet changes in physiological demand, especially in the left pump, often cause atrial wall suction. In this study, a control algorithm to prevent atrial wall suction from occurring in the left atrium by controlling the rotational speed of the right pump, instead of reducing the cardiac output of the left pump, was developed and investigated. The method was tested in a mock circulatory system and in acute animal experiments with adult goats. Two centrifugal pumps were used to totally replace the circulatory function of the natural heart. The cardiac output of each pump was determined independently by a control algorithm running on a computer connected through a serial interface to the pump driving units. Results showed that left atrial wall suction could be prevented using this method, and that the method could be performed simultaneously with physiological control of the artificial heart.

  273. Miniature vibrating flow blood pump using a cross-slider mechanism for external shunt catheter Peer-reviewed

    S Kawano, T Isoyama, S Kobayashi, H Arai, K Takiura, Saito, I, T Chinzei, Y Abe, T Yambe, S Nitta, K Imachi, H Hashimoto

    ARTIFICIAL ORGANS 27 (1) 73-77 2003/01

    Publisher: BLACKWELL PUBLISHING INC

    DOI: 10.1046/j.1525-1594.2003.07186.x  

    ISSN:0160-564X

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    The prototype of the miniature vibrating flow pump (VFP) is developed for the external shunt catheter. The cross-slider mechanism is applied to vibrate the tube, which causes the pumping effect. This mechanism results in successful development of the miniature and lightweight VFP. By the use of the prototype VFP, the experiment of the basic pump performance is made in detail based on the authorized procedure in the research field of fluids engineering. The typical H-Q curve of VFP, which is the relationship between the pump head and the flow rate, can be obtained. This result suggests that the miniature VFP developed here can be expected to be used as the booster pump for the external shunt catheter in clinical applications.

  274. Computational flow visualization in vibrating flow pump type artificial heart by unstructured grid Peer-reviewed

    T Kato, S Kawano, K Nakahashi, T Yambe, S Nitta, H Hashimoto

    ARTIFICIAL ORGANS 27 (1) 41-48 2003/01

    Publisher: BLACKWELL PUBLISHING INC

    DOI: 10.1046/j.1525-1594.2003.07191.x  

    ISSN:0160-564X

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    Computational flow visualization in the casing of vibrating flow pump (VFP) was made for various conditions based on the novel techniques of fluid dynamics. VFP type artificial heart can generate the oscillated flow and can be applied to the left ventricular assist device. Flow pattern of blood in an artificial heart is closely connected to mechanical performance and serious biomechanical problems such as hemolysis and blood coagulation. To effectively design the VFP for a left ventricular assist device, the numerical codes for solving Navier-Stokes equations were developed for three-dimensional blood flow based on the finite volume method. Furthermore, the simulation techniques based on the artificial compressibility method and the unstructured grid were also developed here. The numerical calculations were based on the precise configurations and the flow conditions of the prototype device. From the viewpoint of computational fluid dynamics (CFD), the detailed discussion of flow patterns in the casing of VFP, which were closely connected with hemolysis and blood coagulation, was made and the computational results were visualized by the use of the recent technique of computational graphics. Some useful design data of VFP were presented.

  275. Recent progress in artificial organ research at Tohoku University Peer-reviewed

    T Yambe, M Yoshizawa, A Tanaka, K Abe, S Kawano, H Matsuki, S Maruyama, S Amae, N Wada, T Kamiyama, T Takagi, R Luo, J Hayashi, YA Kovalev, DXD Sha, S Nanka, Y Saijo, Y Mibiki, M Shibata, S Nitta

    ARTIFICIAL ORGANS 27 (1) 2-7 2003/01

    Publisher: BLACKWELL PUBLISHING INC

    DOI: 10.1046/j.1525-1594.2003.07181.x  

    ISSN:0160-564X

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    Tohoku University has developed various artificial organs over the last 30 years. Pneumatic driven ventricular assist devices with a silicone ball valve have been designed by the flow visualization method, and clinical trials have been performed in Tohoku University Hospital. On the basis of these developments, a pneumatic driven total artificial heart has been developed and an animal experimental evaluation was conducted. The development of artificial organs in Tohoku University has now progressed to the totally implantable type using the transcutaneous energy transmission system with amorphous fibers for magnetic shielding. Examples of implantable systems include a vibrating flow pump for ventricular assist device, an artificial myocardium by the use of shape memory alloy with Peltier elements, and an artificial sphincter for patients with a stoma. An automatic control system for artificial organs had been developed for the ventricular assist devices including a rotary blood pump to avoid suction and to maintain left and right heart balance. Based upon the technology of automatic control algorithm, a new diagnostic tool for evaluating autonomic nerve function has been developed as a branch of artificial organ research and this new machine has been tested in Tohoku University Hospital. Tohoku University is following a variety of approaches aimed at innovation in artificial organs and medical engineering fields.

  276. Non-linear dynamic analysis of hemodynamic behavior during virtual reality immersion. Peer-reviewed

    Yambe Tomoyuki, Yoshizawa Makoto, Tanaka Akira, Abe Ken-ichi, Tabayashi Kouichi, Nitta Shin-ichi

    Biomed Pharmacother 56 Suppl 2 367s-369s 2002/04

  277. Non-linear dynamic analysis of hemodynamic parameters in an undulation type artificial heart system. Peer-reviewed

    Yambe Tomoyuki, Abe Yusuke, Isoyama Takashi, Tabayashi Kouichi, Nanka Shunsuke, Imachi Kou, Nitta Shin-ichi

    Biomed Pharmacother 56 Suppl 2 364s-366s 2002/04

  278. 計算負荷とゲーム負荷による心拍変動解析 Peer-reviewed

    大久典子, 半沢秋帆, 菊池亜紀子, 山家智之, 吉田克己, 賀来満夫

    自律神経 39 (2) 204-209 2002/04

  279. In vivo evaluation of pressure head and flow rate estimation on a continuous-flow artificial heart Peer-reviewed

    A Tanaka, Y Aizawa, M Yoshizawa, P Olegario, K Abe, H Takeda, T Yambe, S Nitta

    SECOND JOINT EMBS-BMES CONFERENCE 2002, VOLS 1-3, CONFERENCE PROCEEDINGS 1573-1574 2002

    Publisher: IEEE

    ISSN:1094-687X

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    For monitoring or control of a fully implantable TAH, we should avoid using special sensors that may lose reliability and biocompatibility. Instead of direct measurement of pressure head and flow rate of a centrifugal blood pump, the authors previously proposed a method of estimating these measurements. The method uses an auto-regressive exogenous (ARX) model whose inputs are supplied power, rotational speed and the gain constant expressing the relationship between the two. The gain constant was introduced to compensate for reduction in accuracy caused by the change in blood viscosity or vascular dynamic s. In this study, to ascertain the adequacy of the proposed method, an acute animal experiment was carried out using an adult goat equipped with a TAH consisting of two centrifugal pumps. The results indicated that the ARX model identified even in a mock circulation could estimate flow rate in the recipient accurately enough, although estimation accuracy of pressure head was not high.

  280. Estimation of pressure head and flow rate in a continuous-flow artificial heart - In vivo evaluation Peer-reviewed

    A Tanaka, M Yoshizawa, Y Aizawa, P Olegario, K Abe, T Yambe, S Nitta

    SICE 2002: PROCEEDINGS OF THE 41ST SICE ANNUAL CONFERENCE, VOLS 1-5 527-530 2002

    Publisher: IEEE

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    Instead of direct measurement of pressure head and flow rate of a centrifugal blood pump, the authors previously proposed a method of estimating these measurements. In this study, to ascertain the adequacy of the proposed method, an acute animal experiment was carried out using an adult goat equipped with a TAH consisting of two centrifugal pumps. The results indicated that the ARX model identified even in a mock circulation could estimate flow rate in the recipient accurately enough, although estimation accuracy of pressure head was not high.

  281. Prevention of left atrial wall suction in a continuous-flow total artificial heart by controlling right pump output Peer-reviewed

    PS Olegario, M Yoshizawa, A Tanaka, K Abe, T Yambe, S Nitta, H Takeda

    SICE 2002: PROCEEDINGS OF THE 41ST SICE ANNUAL CONFERENCE, VOLS 1-5 2855-2858 2002

    Publisher: IEEE

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    One of the problems in continuous-flow total artificial heart control is atrial wall suction. In this study. we developed a control algorithm which uses the right pump, to prevent left atrial wall suction from occurring. Results of in vitro and in vivo tests indicate that prevention of left atrial wall suction is possible using this method and that it can be performed simultaneously with physiological control of the artificial heart.

  282. Computational design of vibration pumping device for artificial heart Peer-reviewed

    S Kawano, J Yamakami, K Kamijo, H Hashimoto, T Yambe, S Nitta

    JOURNAL OF PRESSURE VESSEL TECHNOLOGY-TRANSACTIONS OF THE ASME 123 (4) 525-529 2001/11

    Publisher: ASME-AMER SOC MECHANICAL ENG

    ISSN:0094-9930

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    To develop the prototype vibration pumping device for an artificial heart (Hashimoto et at., 1994, ASME J. Fluids Eng., 116, pp. 741-745), the flow patterns in the casing were analyzed experimentally and numerically from the viewpoint of biomechanical engineering. Considering not only the mechanical performance of the pump, but also the hemolysis, was very important to design the artificial heart. In the present study, the curvilinear coordinate transformation technique and the finite difference technique were used to numerically solve the, unsteady, incompressible, and axisymmetric Navier-Stokes equations for the flow field in the various casing configurations of the vibration pumping device. The validity of numerical analysis was confirmed by comparison with the experimental data obtained by the flow visualization technique. Furthermore, the strong dependence of the hemolysis on the flow patterns in the casing was recognized. In Particular, the relationship between the vorticity field in the casing and the hemolysis was elucidated. The results obtained here would provide the useful suggestions for future research and the basic design concept of vibration pumping device for the left ventricular assist device.

  283. [Relationship between depression and lipid metabolism in the elderly with hypertension] Peer-reviewed

    Shizuka K, Yambe T

    Nippon Ronen Igakkai Zasshi 38 (6) 785-790 2001/11

    Publisher: The Japan Geriatrics Society

    DOI: 10.3143/geriatrics.38.785  

    ISSN:0300-9173

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    In order to examine the relationship between depressive symptoms and the lipid metabolism in the elderly with hypertension, we recruited 311 outpatients aged 65 or older with hypertension and defined depression as patients with 6 or more symptoms on Geriatric Depression Scale short form. We further classified depressed patients into three groups: mild depressed with 6-7 symptoms, moderate depressed with 8-10 symptoms and severe depressed with 11 or more symptoms. Serum total cholesterol, serum HDL cholesterol and serum LDL cholesterol levels were significantly higher in female depressed patients than those in nondepressed patients (TC, 194.6±30.1 vs 208.0±32.8 p<0.01; HDL, 67.3±19.3 vs 72.3±16.2 p<0.01; LDL, 107.6±26.5 vs 116.0±29.1 p<0.05). In male patients, serum lipids were not significantly associated with depressive symptoms but depressed patients were significantly older than nondepressed patients (75.3±6.2 vs 78.0±5.9 p<0.05). Concerning the analysis of the severity of depression, serum total cholesterol and serum LDL cholesterol levels were significantly higher in mildly depressed patients than nondepressed patients in females and the same tendency was seen in male patients. No linear associations were shown between the severity of depression and serum lipids. We concluded that hyperlipidemia may be associated with depressive symptoms in elder patients with hypertension and that it might be related the severity of depression. We need to further investigate the relationship between depression and lipid metabolism in larger population samples.

  284. Automatic monitoring system for artificial hearts using self organizing map Peer-reviewed

    XZ Wang, M Yoshizawa, A Tanaka, K Abe, T Yambe, S Nitta, T Chinzei, Y Abe, K Imachi

    ASAIO JOURNAL 47 (6) 686-691 2001/11

    Publisher: LIPPINCOTT WILLIAMS & WILKINS

    DOI: 10.1097/00002480-200111000-00023  

    ISSN:1058-2916

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    This study presents an automatic monitoring system for artificial hearts. The self organizing map (SOM) was applied to monitoring and analysis of an aortic pressure (AoP) signal measured from an adult goat equipped with a total artificial heart. In the proposed system, two different SOMs were used to detect and classify abnormalities in the measured AoP signal. in the first stage, an ordinary SOM, taught with only normal AoP data, was used for detection of abnormalities on the basis of the quantization error in the real-time monitoring task. In the second stage, a supervised SOM was used for classification of abnormalities. The supervised SOM can be regarded as an ordinary SOM with an extra class vector for solving the classification problem. The class vector is assigned to every node in the second SOM as an output weight learned according to Kohonen's learning rule. The effectiveness of detection and classification of abnormalities using these two SOMs was confirmed.

  285. Recent progress on the vibrating flow pump as a totally implantable ventricular assist device Peer-reviewed

    T Yambe, S Kobayashi, T Yoshizawa, T Tanaka, T Matsuki, F Sato, K Tabayashi, S Nitta

    ARTIFICIAL ORGANS 25 (9) 688-691 2001/09

    Publisher: BLACKWELL SCIENCE INC

    DOI: 10.1046/j.1525-1594.2001.06857.x  

    ISSN:0160-564X

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    This study describes the present state of progress in the development of the vibrating flow pump (VFP) ventricular assist system. We have proceeded with development aiming at a totally implantable ventricular assist system with smaller size and lighter weight appropriate for Asians like the Japanese by increasing the drive frequency. An actuator is important for the development of the miniature sized and lightweight artificial heart. We applied a linear motor for the mechanical part at first. The step motor was applied after that. This form may be best if we want the lightweight small sized motor for an actuator. The cross slider form is applied at present. It succeeded in the miniaturization compared with the linear motor. In the VFP-type ventricular assist system, the blood contact parts are a central vibration tube with inflow and outflow chambers. We designed round diaphragms to prevent thrombus formation. In addition, we developed an energy transmission system for total implantation. The VFP creates a high frequency oscillated blood flow. It has a unique flow pattern. Brain blood flow increased although the total flow of the circulation did not change in the frequency of 25 to 30 Hz. The quantitative evaluation of the autonomic nerve function during the left heart assistance with an oscillated blood flow was carried out by spectral analysis. Some influences on an autonomic nerve were observed by the VFP left heart assistance. We will continue development research with the aim of clinical application.

  286. Development of an implantable artificial anal sphincter by the use of the shape memory alloy Peer-reviewed

    S Amae, M Wada, Y Luo, H Nakamura, S Yoshida, T Kamiyama, T Yambe, T Takagi, S Nitta, R Ohi

    ASAIO JOURNAL 47 (4) 346-350 2001/07

    Publisher: LIPPINCOTT WILLIAMS & WILKINS

    DOI: 10.1097/00002480-200107000-00010  

    ISSN:1058-2916

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    In this study, we developed and assessed an artificial anal sphincter driven by an shape memory alloy actuator (AS-SMA). The performance characteristics of the device were analyzed with a measurement system. Assessment showed that the AS-SMA could generate a pressure of 55 mm Hg at an atmospheric temperature of 36 degreesC, and displacement of the SMA actuator was 7.5 mm when the temperature of the SMA plate was 55 degreesC. To evaluate opening and closing, we studied a piglet colostomy model, in which the AS-SMA was implanted around the colostomy in the extraperitoneal space. Flow control tests using living porcine intestine revealed that the AS-SMA could maintain fecal continence against an intestinal pressure of 75 mm Hg. The high pressure zone corresponding to the location of the device was demonstrated in a manometric examination. For 6 days after surgery, we activated the AS-SMA twice a day and observed the bowel movements. The animal experiment indicated that the AS-SMA is able to control the bowel movements of patients with fecal incontinence if several problems, such as burning of tissue around the device and compression injury of the intestine, are resolved.

  287. Fluctuations of Emax of the left ventricle: effect of atrial natriuretic polypeptide. Peer-reviewed

    Yambe T, Yoshizawa M, Taira R, Tanaka A, Iguchi A, Tabayashi K, Tobita S, Nitta S

    Biomed Pharmacother 55 Suppl 1 147s-152s 2001/04

  288. Automatic detection and classification of abnormalities for artificial hearts using a hierarchical self-organizing map Peer-reviewed

    XZ Wang, M Yoshizawa, A Tanaka, K Abe, T Yambe, S Nitta

    ARTIFICIAL ORGANS 25 (2) 150-153 2001/02

    Publisher: WILEY-BLACKWELL

    DOI: 10.1046/j.1525-1594.2001.06544-2.x  

    ISSN:0160-564X

    eISSN:1525-1594

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    A hierarchical self-organizing map (SOM) has been developed for automatic detection and classification of abnormalities for artificial hearts. The hierarchical SOM has been applied to the monitoring and analysis of an aortic pressure (AoP) signal measured from an adult goat equipped with a total artificial heart. The architecture of the network actually consists of 2 different SOMs. The first SOM clusters the AoP beat patterns in an unsupervised way. Afterward, the outputs of the first SOM combined with the original time-domain features of beat-to-beat data are fed to the second SOM for final classification. Each input vector of the second SOM is associated with a class vector. This class vector is assigned to every node in the second map as an output weight and learned according to Kohonen's learning rule. Some experimental results revealed that a certain abnormality caused by breakage of sensors could be identified and detected correctly and that the change in the state of the circulatory system could be recognized and predicted to some extent.

  289. A single-beat estimation method for Emax directly based on linearity of ventricular elastance Peer-reviewed

    M Yoshizawa, M Yokogawa, A Tanaka, K Abe, H Takeda, Y Saijo, T Yambe, S Nitta

    PROCEEDINGS OF THE 23RD ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY, VOLS 1-4 23 155-155 2001

    Publisher: IEEE

    ISSN:1094-687X

  290. In vivo evaluation of pressure head and flow rate estimation in a continuous-flow artificial heart Peer-reviewed

    A Tanaka, M Yoshizawa, T Yamada, K Abe, H Takeda, T Yambe, S Nitta

    PROCEEDINGS OF THE 23RD ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY, VOLS 1-4 23 3060-3063 2001

    Publisher: IEEE

    ISSN:1094-687X

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    To avoid using sensors with low biocompatibility and low durability in implantable TAH systems, the authors previously proposed a new method for estimating instantaneous values of flow rate and pressure head on the basis of voltage, current and rotational speed in a motor driven centrifugal pump. The previous in vitro experiments showed that the proposed estimator could automatically compensate for the effect of the change in blood viscosity on the estimation accuracy by employing two kinds of auto-regressive exogenous model. In this study, validity and reliability of this estimation method were ascertained in an acute animal experiment. In the experiment, two centrifugal blood pumps were implanted into an adult goat as a total artificial heart. Results of estimation were compared with true values when blood viscosity was changed by injecting physiological saline. The results indicated that the system could successfully estimate pressure head by compensating the change of viscosity although the estimation accuracy of the in vivo estimation was not so high as that of the previous in vitro tests.

  291. Totally implantable ventricular assist system that can increase brain blood flow Peer-reviewed

    T Yambe, N Owada, S Kobayashi, A Tanaka, M Yoshizawa, K Abe, K Tabayashi, H Takeda, H Hashimoto, S Nitta

    ARTIFICIAL ORGANS 24 (8) 644-647 2000/08

    Publisher: BLACKWELL SCIENCE INC

    DOI: 10.1046/j.1525-1594.2000.06608.x  

    ISSN:0160-564X

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    In the clinical usage of the ventricular assist device (VAD), multiple organ failure becomes an important problem. To improve the clinical record of the VAD, another organ function may be vitally important. For that reason. we have been developing a VAD system aiming at improving another organ's function. Development of the vibrating flow pump (VFP), which can generate a very unique Row pattern from 10 Hz to 50 Hz, was ongoing in our Institute. In order to evaluate brain blood flow and oxygen consumption, HbO(2) was measured with a NIRO monitoring device in healthy adult goats. Four goats were anesthetized with halothane inhalation, then left thoracotomy was performed for the left heart bypass. HbO(2) of the brain was measured by recording of the hemodynamic variables during left heart assistance with the VFP system. During left heart bypass with the VFP system, hemodynamic parameters stayed within normal range, and satisfactory pump output was easily obtained. Pump output stayed within 20-40% bypass to evaluate the effect of high frequency oscillated assist now on brain blood flow during the same cardiac output. interesting results were observed during the experiments. During 30 Hz drive of the VFP left heart assistance, HbO(2) suggested that brain blood flow significantly increased compared with another drive frequency assistance during the same total cardiac output. These results suggest that we can control the brain blood flow with a totally implantable VAD system such as the VFP system.

  292. Cerebral blood oxygenation changes during ventricular assitance with vibrating flow pump Peer-reviewed

    T. Yambe, S. Kobayashi, N. Owada, S. Nanka, S. Nitta, M. Yoshizawa, H. Hashimoto

    ASAIO Journal 46 (2) 162 2000

    Publisher: Lippincott-Raven Publ

    DOI: 10.1097/00002480-200003000-00046  

    ISSN:1058-2916

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    Aiming at a totally implantable type ventricular assist device (VAD), we adopted the design concept of short stroke volume and high frequency. The transcutaneous energy transmission system (TETS) using the amorphous fiber was developed to constitute the totally implantable VAS system. Vibrating flow pump (VFP), which was developed by the concept of short stroke volume, works with high frequency compared with a natural heart of a biological system. It is frequency of 10-50 Hz. In this research, the animal experiments of the left ventricular assistance were carried out with the healthy adult goats. All hemodynamic data were stored in the magnetic tape and analyzed in the computer system through the AD converter. TETS with amorphous fibers showed enough performance and temperature rise were not so significant. During left heart bypass with VFP, cerebral blood oxygenation was measured with Near infrared oxygenation monitoring equipment (NIRO). As the results, according to an alteration of the drive frequency, cerebral blood oxygen saturation was significantly altered, even during same total cardiac output and same bypass ratio. This result suggested the altered brain blood flow. Thus, it may be possible to control the brain blood flow by the selection of the drive frequency of VAD. We want to continue the development toward the one of the candidates of the totally implantable VAD.

  293. C104 形状記憶合金を用いた人工肛門括約筋の開発

    天江 新太郎, 和田 基, 吉田 茂彦, 神山 隆道, 大井 龍司, 山家 智之, 仁田 新一, 中村 博一, 羅 雲, 高木 敏行

    日本小児外科学会雑誌 36 (3) 338-338 2000

    Publisher: 特定非営利活動法人 日本小児外科学会

    DOI: 10.11164/jjsps.36.3_338_2  

  294. Monitoring system for the totally implantable artificial heart by the use of the sensors for a virtual reality system and micromachine Peer-reviewed

    Yambe Tomoyuki, Tanaka Akira, Nitta Shin-ichi

    IEEJ Transactions on Sensors and Micromachines 120 (6) 280-284 2000

    DOI: 10.1541/ieejsmas.120.280  

    ISSN:1347-5525 1341-8939

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    For the development of totally implantable artificial organs, effective monitoring of implantable devices is crucial. In this study, a sensor for a 3-dimensional (3-D) virtual reality (VR) system and micromachine were used to provide such monitoring. The position sensors were attached to the inner actuating parts of the artificial heart system. Using these VR position sensors, we could easily detect the position and movement, and pitch, yaw, and roll. An experimental evaluation was performed using moc circulation loop and healthy adult goats were performed. By the use of chronic animal experiments using healthy adult goats, micro pressure sensors implanted into the cannulae as part of a ventricular assist system were evaluated. The experimental results suggest that our newly developed implantable sensors for monitoring the implantable artificial heart system would be useful for sensing driving condition, and thus for implantable devices for clinical use. © 2000, The Institute of Electrical Engineers of Japan. All rights reserved.

  295. Detection of the cardiac function by fractal dimension analysis Peer-reviewed

    T Yambe, S Nanka, S Kobayashi, A Tanaka, N Owada, M Yoshizawa, K Abe, K Tabayashi, H Takeda, T Nishihira, S Nitta

    ARTIFICIAL ORGANS 23 (8) 751-756 1999/08

    Publisher: BLACKWELL SCIENCE INC

    DOI: 10.1046/j.1525-1594.1999.06416.x  

    ISSN:0160-564X

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    Nonlinearity in circulation control attracts attention because nonlinearity is thought to be essential in the function of the living body. Many investigators have pointed out that the analysis of heart rate variability in particular is important in the analysis of autonomic nerve and cardiac function evaluation. Heart rate variability shows nonlinear behavior. However, until the present, many reports have been premised on linearity; linear correlation by frequency analysis has been used by many studies. However, in terms of this methodology, there is a problem applying it to the nonlinear living body. Therefore, fractal and chaos methodology has been used. The ascertainment of cardiac function has become important in allowing the clinical stage of a ventricular assist system to be successful. The purpose of this study was cardiac function evaluation by a methodology that was premised on nonlinearity. Chaos and fractal theory was used as a nonlinear dynamic theory. As a methodology of measurement, the volume of the left ventricle was used rather than an electrocardiogram, the waveform of arterial blood pressure. The volume was measured using acoustic quantification (AQ) ultrasonic echocardiography. Using these methodologies, the time series of many patients were analyzed. For example, drug administration was attempted in this study, and it was found that some drugs like ACE inhibitors showed a significant effect upon nonlinear dynamics in the cardiovascular system. The result, which attempted cardiac function evaluation by these various methodologies, is reported.

  296. Peripheral vascular resistances during total left heart bypass with an oscillated blood flow Peer-reviewed

    T Yambe, S Kawano, S Nanka, S Kobayashi, A Tanaka, N Owada, M Yoshizawa, K Abe, K Tabayashi, H Takeda, H Hashimoto, S Nitta

    ARTIFICIAL ORGANS 23 (8) 747-750 1999/08

    Publisher: BLACKWELL SCIENCE INC

    DOI: 10.1046/j.1525-1594.1999.06415.x  

    ISSN:0160-564X

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    For development aimed at a totally implantable type ventricular assist device (VAD), the vibrating flow pump (VFP) has been developed at Tohoku University. A transcutaneous energy transmission system (TETS) using amorphous fibers was developed to power the totally implantable VAD system. The VFP works at a high frequency compared to that of a natural heart of a biological system. It is a frequency of 10-50 Hz. In this research, animal experiments with left heart bypass were carried out with healthy adult goats. For comparison between nonpulsatile now and oscillated flow, a rotary pump (RP) and the VFP were used in the experiments. For the achievement of total left heart bypass, left ventricular approaches were carried out, and blood was pumped from the left ventricle to the descending aorta. Adequate support of the left heart was provided by both pumps. In terms of the results, the vascular resistances tended to decrease during the use of both pumps during 100% bypass driving. When we compared these pumps at the same flow rate, the resistances during RP driving were significantly smaller than those during VFP driving. These results may suggest that the influences of the VFP upon the peripheral vessels may be relatively small compared to those of the RP. This may be an important result when a stable hemodynamic condition is required during artificial circulation. The VFP was considered as a candidate for a totally implantable VAD as a result.

  297. Total vascular resistance and blood flow frequency during left ventricular assistance using a vibrating flow pump Peer-reviewed

    S Kobayashi, N Owada, T Yambe, S Nitta, T Fukuju, T Hongoh, H Hashimoto

    ARTIFICIAL ORGANS 23 (8) 732-735 1999/08

    Publisher: BLACKWELL SCIENCE INC

    DOI: 10.1046/j.1525-1594.1999.06412.x  

    ISSN:0160-564X

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    A vibrating flow pump (VFP) can generate high frequency oscillated blood now within 10-30 Hz by the oscillation of its central tube. A totally implantable artificial heart using a VFP is being developed as a unique type of blood pump. In this study, left ventricular (LV) assist circulation was performed using a VFP. The total vascular resistance and driving frequency of the VFP were estimated from their relationship. The effect of oscillation on the vascular system was studied by the frequency analysis method and vascular impedance. Adult goats were anesthetized by halothane using an inhaler and a left fourth thoracotomy was performed. The inflow cannula was inserted into the left ventricle, and the outflow cannula was sutured to the descending aorta. The VFP and a centrifugal pump were set in parallel for alternation and comparison. The driving frequency of the VFP was changed and included 15; 20, 25, and 30 Hz. The hemodynamic parameters were continuously recorded during experiments by a digital audio tape (DAT) data recorder. The internal pressure of the left ventricular cavity and aortic pressure were monitored by the pressure manometers continuously. One hundred percent LV assistance was judged by the separation of LV and aortic pressure. The total vascular resistance was decreased by the start of operation of each pump. The decrease during flow using the VFP was not as large as that using a centrifugal pump (CP). The arterial input impedance during oscillated blood flow by the VFP showed a slow curve appearance. It was similar to the frequency characteristics curve of natural heart beats within the lower frequencies. The study of arterial impedance may be important for the estimation of the reflection of the pulsatile wave from the arterial branch, among other things.

  298. Vagal nerve activity recording in the awake condition for the control of an artificial heart system Peer-reviewed

    T Yambe, S Nanka, S Kobayashi, A Tanaka, M Yoshizawa, T Abe, K Tabayashi, H Takeda, S Nitta

    ARTIFICIAL ORGANS 23 (6) 529-531 1999/06

    Publisher: BLACKWELL SCIENCE INC

    DOI: 10.1046/j.1525-1594.1999.06396.x  

    ISSN:0160-564X

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    To detect useful information for an artificial heart control system, we paid attention to the autonomic nervous system. For stable recording, we used vagal nerve activity in chronic animal experiments using healthy adult goats in an awake condition because this nerve was sufficiently bold and large enough. Vagal nerve discharges were successfully recorded from awake goats. They were synchronized with respiration and responded to the hemodynamic changes induced by drug administration, suggesting that they may provide useful information for an artificial heart control algorithm. For automatic control, some time delay plays a vitally important role. Thus, predictive control for an artificial heart system may be desirable. It may be embodied by the use of autonomic nerve information.

  299. Vagal nerve activity and the high frequency peak of the heart rate variability. Peer-reviewed

    Yambe T, Nanka S, Kobayashi S, Tanaka A, Yoshizawa M, Abe K, Tabayashi K, Takeda H, Nitta S

    Int J Artif Organs 22 (5) 324-328 1999/05

  300. Monitarinf System for the Totally Implantable Artificial Organs by the Use of the Sensors for a Virtual Reality System and Micromachine

    YAMABE T., KOBAYASHI S., NANKA S., TABAYASHI K., YOSHIZAWA M., FUKUTOME A., NITTA S.

    Journal of the Japanese Society for Artificial Organs and Tissues 28 (2) 557-560 1999/04/15

    Publisher: JAPANESE SOCIETY FOR ARTIFICIAL ORGANS

    DOI: 10.11392/jsao1972.28.557  

    ISSN:0300-0818

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    For the development of totally implantable artificial organs, effective monitoring of implantable devices is crucial. In this study, a sensor for a 3-dimensional (3-D) virtual reality (VR) system and micromachine were used to provide such monitoring. The position sensors were attached to the inner actuating parts of the artificial heart system. Using these VR position sensors, we could easily detect the position and movement, and pitch, yaw, and roll. An experimental evaluation was performed using moc circulation loop and healthy adult goats were performed. By the use of chronic animal experiments using healthy adult goats, micro pressure sensors implanted into the cannulae as part of a ventricular assist system were evaluated. The experimental results suggest that our newly developed implantable sensors for monitoring the implantable artificial heart system would be useful for sensing driving condition, and thus for implantable devices for clinical use.

  301. A future prediction type artificial heart system Peer-reviewed

    T Yambe, N Tanizuka, A Tanaka, M Yoshizawa, K Abe, H Takeda, K Tabayashi, S Nitta

    ARTIFICIAL ORGANS 23 (3) 268-273 1999/03

    Publisher: BLACKWELL SCIENCE INC

    DOI: 10.1046/j.1525-1594.1999.06321.x  

    ISSN:0160-564X

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    The demand of the biological system needs to be predicted to consider the quality of life (QOL) of a patient with an artificial heart system. The purpose of this study was the prediction of the imminent cardiac output and the predictive control for an artificial heart. For that purpose, autonomic nerve information was applied in this study. Nervous sympathicus action potentials were measured, and a prediction function of cardiac output was made using the sympathetic tone and preload and afterload measurement with multiple regression analysis. The predicted value showed significant correlation with the measured value after 2.9 s. Currently, however, long-term instrumentation of the nervous sympathicus potential is difficult. Thus, hemodynamic fluctuations, which recently have attracted attention, were used in this study. A prediction function using the Mayer wave, which represented nervous sympathicus, was determined. As a result, midterm prediction became possible. Furthermore, a measurement of the vagal nerve was used as a possible long-term prediction parameter. For long-term prediction, Hurst exponent analysis was used in this study. Vagal nerve discharges in the changing position showed alteration of longterm determination. In conclusion, the future prediction control of an artificial heart takes shape using these prediction functions.

  302. Successful closure of coronary-bronchial artery fistula with vein graft-coated stent Peer-reviewed

    Y Saijo, K Izutsu, T Sonobe, Y Okuyama, T Yambe, S Nitta

    CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS 46 (2) 214-217 1999/02

    Publisher: WILEY-LISS

    DOI: 10.1002/(SICI)1522-726X(199902)46:2<214::AID-CCD22>3.0.CO;2-J  

    ISSN:1522-1946

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    A coronary-bronchial fistula and aneurysmal dilatation of the proximal part of the fistula was successfully closed using an autologous Vein graft-coated stent (Palmaz-Schatz stent). This is the first report that demonstrates the feasibility of the vein-coated stent for the treatment of congenital disease. (C) 1999 Wiley-Liss, Inc.

  303. Chaotic dynamics in circulation with Tohoku University vibrating flow pump Peer-reviewed

    S Nitta, T Yambe, SI Kobayashi, H Hashimoto, M Yoshizawa, H Mastuki, K Tabayashi, H Takeda

    ARTIFICIAL ORGANS 23 (1) 119-123 1999/01

    Publisher: BLACKWELL SCIENCE INC

    DOI: 10.1046/j.1525-1594.1999.06288.x  

    ISSN:0160-564X

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    For the development of a totally implantable ventricular assist system (VAS), we have been developing the vibrating flow pump (VFP), which can generate oscillated blood flow with a relative high frequency (10-50 Hz) for a totally implantable system. In this study, the effects of left ventricular assistance with this unique oscillated blood flow were analyzed by the use of nonlinear mathematics for evaluation as the whole circulatory regulatory system, not as the decomposed parts of the system. Left heart bypasses using the VFP from the left atrium to the descending aorta were performed in chronic animal experiments using healthy adult goats. The ECG, arterial blood pressure, VFP pump flow, and the flow of the descending aorta were recorded in the data recorder during awake conditions and analyzed in a personal computer system through an A-D convertor. By the use of nonlinear mathematics, time series data were embedded into the phase space, the Lyapunov numerical method, fractal dimension analysis, and power spectrum analysis were performed to evaluate nonlinear dynamics. During left ventricular assistance with the VFP, Mayer wave fluctuations were decreased in the power spectrum, the fractal dimension of the hemodynamics was significantly decreased, and peripheral vascular resistance was significantly decreased. These results suggest that nonlinear dynamics, which mediate the cardiovascular dynamics, may be affected during left ventricular (LV) bypass with oscillated flow. The decreased power of the Mayer wave in the spectrum caused the limit cycle attractor of the hemodynamics and decreased peripheral resistance. Decreased sympathetic discharges may be the origin of the decreased Mayer wave and fractal dimension. These nonlinear dynamic analyses may be useful to design optimal VAS control.

  304. Origin of chaos in the circulation: open loop analysis with an artificial heart. Peer-reviewed

    Yambe T, Nanka S, Kobayashi S, Tanaka A, Yoshizawa M, Abe K, Tabayashi K, Takeda H, Nitta S

    ASAIO J 44 (5) M700-3 1998/09

  305. Continuous monitoring of autonomic nerve information for the control of an artificial heart. Peer-reviewed

    Yambe T, Nomura T, Nanka S S, Kobayashi S, Tanaka A, Yoshizawa M, Abe K, Tabayashi K, Takeda H, Nitta S

    ASAIO J 44 (5) M696-9 1998/09

  306. Development of total artificial heart with economical and durability advantages Peer-reviewed

    T Yambe, A Fukutome, S Kobayashi, S Nanka, M Yoshizawa, K Tabayashi, H Takeda, S Nitta

    INTERNATIONAL JOURNAL OF ARTIFICIAL ORGANS 21 (5) 279-284 1998/05

    Publisher: WICHTIG EDITORE

    ISSN:0391-3988

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    To develop a total artificial heart (TAH) pump system, we created a design paying particular attention to durability and cost. We adopted a pneumatically driven sac type artificial heart, where the configuration of the sac was decided according to the methodology of flow visualization. Ifs configuration is almost round to achieve as little stagnation as possible and a low turbulent flow. The main body of the sac was made using polyvinyl chloride (PVC) paste. The paste was poured into an external mold, and heated in a hot air drying oven. Coating was performed using polyurethane. The basic performance of this pump system was tested using a model circulation circuit, and a fitting study through acute animal experiment, using a healthy adult goat, was carried out. As for the TAH produced experimentally a pump output exceeding 5.0 l/min in the model circulation circuit was provided. Implantation in the internal pleural cavity of a healthy adult goat, 55 kg in weight, proved possible and quite easy in comparison. It is thought that a more refined design in the connector part is desirable. Furthermore, a chronic experiment with the TAH will be carried out, and examination will need to be repeated in the future.

  307. Control of the pulmonary arterial resistance by the use of the oscillated assist flow Peer-reviewed

    T Yambe, K Izutsu, H Hashimoto, M Yoshizawa, A Tanaka, K Abe, T Fukuju, M Miura, K Tabayashi, H Takeda, K Shizuka, T Sonobe, S Naganuma, S Kobayashi, S Nanka, S Nitta

    ARTIFICIAL ORGANS 22 (5) 430-433 1998/05

    Publisher: BLACKWELL SCIENCE INC

    ISSN:0160-564X

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    In the clinical application of supporting circulation, the treatment of a patient with pulmonary hypertension is very important. We developed the electromagnetically driven vibrating flow pump (VFP) as a totally implantable type ventricular assist system. The artificial heart driven by electromagnetic forces creates high speed oscillation now around 10-50 Hz. Assistance by highspeed oscillation flow has an interesting influence on the cardiovascular system. In this study, we carried out research on the influence such oscillation flow had on the pulmonary arterial vessels, and the supporting flow waveform that controlled pulmonary vascular resistance was considered. Six healthy adult goals of both sexes were used in the experiments. We carried out inhalation anesthesia and performed intubation. The thorax was opened through left fourth rib resection. Right heart bypass was performed from the right atrium to the pulmonary artery. The now of right heart assistance was maintained within 20-25% of total flow. Our purpose was to add flow of a specific high frequency to the right heart circulation, The hemodynamic parameters were recorded on a magnetic tape data recorder and input into a computer through an A-D converter. A result identified was that the pulmonary vascular resistance changed according to the alteration of the driving frequency of the VFP even during the same flow assistance. The resistance of the pulmonary arterial vessels became smaller when the driving of the VFP of 30 Hz was added to the right heart circulation. This was significant even when compared with continuous flow right heart assist. The characteristics of impedance appeared to have interesting alterations as well. Control of pulmonary vascular resistance by right heart assistance becomes possible if these results are applied. Accordingly, it may become one of the choices far treatment of a patient with pulmonary hypertension.

  308. TOTALLY IMPLANTABLE VENTRICULAR ASSIST SYSTEM USING THE VIBRATING FLOW PUMP FROM JAPAN

    YAMBE T., HONGO T., KOBAYASHI S., OWADA N., NANKA S., NAGANUMA S., KAKINUMA Y., FUKUJU T., TABAYASHI T., TANAKA A., ABE K., MATSUKI H., YOSHIZAWA M., HASHIMOTO H., TAKEDA H., NITTA S.

    Journal of the Japanese Society for Artificial Organs and Tissues 27 (2) 325-329 1998/04/15

    Publisher: JAPANESE SOCIETY FOR ARTIFICIAL ORGANS

    DOI: 10.11392/jsao1972.27.325  

    ISSN:0300-0818

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    Aiming at a totally implantable type ventricular assist device (VAD), Vibrating flow pump (VFP) was developed in Tohoku University. The transcutaneous energy transmission system (TETS) using the amorphousness fiber was developed to constitute the totally implantable VAD system. Artificial heart works with high frequency compared with a natural heart. It is frequency of 10-50 Hz. In this research, animal experiment was carried out with the healthy adult goats. Blood from left ventricular apex was received, and sent to descending aorta. Enough supporting effect of left heart was provided. In particular, depression effect of left ventricle was obvious. As a result, enough artificial heart flow was provided. For the totally implantable type VAD, left heart bypass of almost 100% may be necessary in some situations. So, apex approaches of the left heart bypass may be desirable. From the anatomical consideration, , an apex of a heart is suitable for the totally implantable VFP. In the left heart bypass with left apical approach, almost 100 % bypass was possible, which is important for natural heart to wait for recovery of enough cardiac function. And it is important that left heart circulation is maintained fully. In summary, VFP was considered to be useful as a totally implable type left ventricular assist device.

  309. Non-destructive Detection of Material Fatigue in Artificial Heart by Scanning Acoustic Microscopy

    SAIJO Yoshifumi, OKAWAI Hiroaki, SASAKI Hidehiko, YAMBE Tomoyuki, NITTA Shin-ichi, TANAKA Motonao, KOBAYASHI Kazuto, HONDA Yosuke

    Transactions of Visualization Society of Japan 18 (70) 187-191_1 1998

    Publisher: The Visualization Society of Japan

    DOI: 10.3154/jvs.18.70_187  

    ISSN:0916-4731

  310. Identification and adaptive control of cardiovascular system driven by a total artificial heart Peer-reviewed

    A Tanaka, M Yoshizawa, K Abe, T Yambe, S Nitta, Y Abe, K Imachi

    (SYSID'97): SYSTEM IDENTIFICATION, VOLS 1-3 1259-1262 1998

    Publisher: PERGAMON PRESS LTD

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    To reflect the autonomic nervous information in a control strategy of a total artificial heart, a new vascular resistance-based adaptive controller has been developed. A main function of this controller is automatic adaptation for changes in cardiovascular dynamics such as time variation as well as individual differences. Experiments were executed in a mock circulatory system. This revealed that the proposed system could automatically adjust cardiac output to maintain aortic pressure in accordance with artificial change in peripheral vascular resistance.

  311. Open-loop analysis of transfer characteristics from blood pressure to heart rate using effectively total artificial heart Peer-reviewed

    A Tanaka, M Yoshizawa, T Nomura, K Abe, H Takeda, T Yambe, S Nitta, Y Abe, T Chinzei, K Imachi

    PROCEEDINGS OF THE 20TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY, VOL 20, PTS 1-6 20 454-457 1998

    Publisher: IEEE

    ISSN:1094-687X

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    It is desirable that the dynamic behavior of the drive rate of the artificial heart can be as similar as possible to that of the recipient&apos;s heart rate (HR) before implantation. This requires a model which can simulate the behavior of BR on the basis of only information measured with the limited number of approvable sensors. This paper has given a linear time series model for explaining the behavior of HR only with aortic pressure (AOP) and right atrial pressure(RAP). This could be obtained from open-loop analysis using effectively total artificial heart which was introduced for measuring ETR in vivo and for eliminating its effect on blood pressure.

  312. Making chaos with an artificial heart system Peer-reviewed

    T Yambe, M Yoshizawa, K Abe, A Tanaka, H Takeda, S Nitta

    PROCEEDINGS OF THE 20TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY, VOL 20, PTS 1-6 20 1561-1564 1998

    Publisher: IEEE

    ISSN:1094-687X

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    If chaotic dynamics is useful for the creatures, we must consider its application to the Total Artificial Heart (TAH) system. We tried to make chaos in an electrical circuit model and Moc circulation and acute & chronic animal experiments using TAH automatic control algorithm. If we consider from a viewpoint of artificial heart control, baroreflex delay means the control delay of an artificial heart. Firstly, chaotic dynamics were observed in an electric simulation model with some time delay. In next step. we confirm the achievement of chaotic dynamics In an artificial heart circulation with automatic control algorithm simulating baroreflex system in the chronic animal experiments. The reconstructed attractor of the artificial heart pump output in chronic animal experiments under awake condition suggests the formation of a strange attractor in the phase space during automatic TAH control algorithm, and the positive largest Lyapunov exponents suggest a chaotic system. Our results suggest that we can achieve the chaotic dynamics by the use of the TAH automatic control algorithm, similar to the baroreflex system.

  313. An approach to singe-beat estimation of E(max) as an inverse problem Peer-reviewed

    M Yoshizawa, A Tanaka, K Abel, H Takeda, Y Kakinuma, T Yambe, S Nitta

    PROCEEDINGS OF THE 20TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY, VOL 20, PTS 1-6 20 379-382 1998

    Publisher: IEEE

    ISSN:1094-687X

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    The present study has derived a new method for estimating the maximum value (E(max)) of the ventricular elastance (E(t)) without direct measurement of the ventricular volume (V(t)) by regarding the estimation process as an inverse problem. The method can estimate Em,, in a single beat without any change in preload or afterload by measuring the ventricular pressure (P(t)) and outflow (i(t)) which is much easier to measure than V(t). This method is based on two assumptions that E(t) can be approximated by at + b and that V(ed) - V(o) = I(t) + P(t)/E(t) holds for any t during the ejection period, where V(ed) is the end-diastolic volume, I(t) is the integrated value of i(t) and Vo is the volume axis intercept of the regression line of the end-systolic pressure-volume relation. In vivo experiments using two adult goats resulted in small mean equation error with respect to V(ed) - V(o) less than about 5% of the stroke volume of each heart beat. This implies that the proposed method is practical enough to monitor cardiac function in actual clinical settings.

  314. Acoustic properties of dialysed kidney by scanning acoustic microscopy Peer-reviewed

    H Sasaki, Y Saijo, M Tanaka, S Nitta, Y Terasawa, T Yambe, Y Taguma

    NEPHROLOGY DIALYSIS TRANSPLANTATION 12 (10) 2151-2154 1997/10

    Publisher: OXFORD UNIV PRESS

    DOI: 10.1093/ndt/12.10.2151  

    ISSN:0931-0509

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    Background, A correlation between acquired renal cysts in the dialysed kidney and renal cancer has long been debated, but no changes in the physical properties of kidneys at the microscopic level have been reported. The purpose of the present study was to classify the physical properties of the kidneys of patients undergoing haemodialysis at several stages of pathology by use of the scanning acoustic microscope. Methods, Sixteen surgically excised kidneys of dialysis patients were investigated. Tissues were fixed in 10% formalin, frozen in acetone, and cut 10 mu m thick on a cryostat. We used a scanning acoustic microscope operated in the frequency range of 100-200 MHz. Attenuation constant and sound speed were measured on a two-dimensional distribution. Results, The attenuation constant for inflammatory granulation tissue was significantly higher than that for hyaline degeneration tissue (P&lt;0.001). Sound speed was high for granulation tissue, but tended to diminish gradually for hyaline degeneration. Sound speed increased again with progression to cystic degeneration (P&lt;0.001), but the attenuation constant remained low. When a cystic kidney contained a malignant lesion, the previously low attenuation constant rose at that site (P&lt;0.001), and the previously high sound speed was diminished (P&lt;0.001). Conclusion, Our data suggest that the physical properties of dialysed kidneys at different stages of pathology can be classified by their acoustic properties. Simultaneous evaluation of attenuation constant and sound speed is considered applicable to determining whether tissues contain malignant elements.

  315. Classical but effective techniques for estimating cardiovascular dynamics. Peer-reviewed

    Yoshizawa M, Abe K, Takeda H, Yambe T, Nitta S

    IEEE Eng Med Biol Mag 16 (5) 106-112 1997/09

    DOI: 10.1109/51.620501  

  316. Pulmonary arterial impedance analysis by the use of the oscillated assist flow Peer-reviewed

    T Yambe, K Shizuka, K Izutsu, T Sonobe, S Naganuma, S Kobayashi, S Nanka, H Hashimoto, M Yoshizawa, K Tabayashi, H Takeda, S Nitta

    ARTIFICIAL ORGANS 21 (7) 751-754 1997/07

    Publisher: BLACKWELL SCIENCE INC

    ISSN:0160-564X

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    Pulmonary arterial impedance is an important and interesting characteristic that can be used to evaluate the physiological properties of the pulmonary vessel. However, power spectrum analysis of the pulmonary artery pressure and flow pattern have suggested that peak power in the relatively high frequency range (&gt;10 Hz) is significantly low; thus, we cannot analyze the vessel properties in the high frequency range. In this study, we used the newly developed vibrating flow pump (VFP), which can generate oscillated blood now with a relatively high frequency (10-50 Hz) for right heart bypass, to evaluate the pulmonary arterial impedance pattern in the high frequency range. Acute animal experiments of the right heart bypass from the right atrium to the pulmonary artery using 6 healthy adult goats were performed. The flow pattern and pressure of the pulmonary artery, electrocardiograms (ECGs), and arterial and right atrial pressures were continuously monitored during the experiments. Spectral analysis of the hemodynamic parameters using the fast Fourier transform (FFT) method was performed to evaluate the spectral properties. The coherence function, transfer function, and phase patterns were calculated to analyze the impedance pattern in the relatively high frequency area. Previously, various investigators had tried to analyze the impedance patterns of the pulmonary artery; however, they could not analyze the impedance patterns over 10 Hz because the spectral patterns of the pulmonary flow do not have high power at high frequencies. These physiological analyses may be useful in designing the optimal pulmonary circulation.

  317. Development of a novel centrifugal pump: Magnetic rotary pump Peer-reviewed

    S Naganuma, T Yambe, T Sonobe, S Kobayashi, S Nitta

    ARTIFICIAL ORGANS 21 (7) 746-750 1997/07

    Publisher: BLACKWELL SCIENCE INC

    ISSN:0160-564X

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    The rotational axis of the centrifugal pump has some associated problems such as blood destruction and sealing between the axis and pump housing. To improve upon these deficits we have developed a new type of blood pump, the magnetic rotary pump (MRP). The MRP has an original design with no rotational axis and no impellers. We made a prototype MRP and examined its hemodynamics in mock circulation. The prototype MRP flow rate is only 1.0 L/min with an afterload of 30 mm Hg, and we have made some modifications in the size and drive mechanisms from these results. The modified MRP can achieve high flow rates and rotational speeds (6.0 L/min with an afterload of 100 mm Hg, 2,000 rpm) in a mock circuit, and the modified MRP was used for left heart assistance in an acute animal experiment. The MRP could maintain the hemodynamics of an anesthetized adult goat. These results suggest that the MRP needs to be improved in several areas, but the MRP may be useful as a blood pump.

  318. Hemolysis test of disposable type vibrating flow pump Peer-reviewed

    S Kobayashi, S Nitta, T Yambe, T Sonobe, S Naganuma, H Hashimoto

    ARTIFICIAL ORGANS 21 (7) 691-693 1997/07

    Publisher: BLACKWELL SCIENCE INC

    ISSN:0160-564X

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    The vibrating flow pump (VFP) can generate high frequency oscillated blood flow. Because of the high frequency driving with short stroke volume, the pump system can be small. The disposable type VFP (D-VFP) was developed for use for extracorporeal circulation. The electromagnetic actuator was detached from the vibrating tube, which was newly designed to be a disposable tube with a jellyfish valve. Hemolysis tests of the D-VFP, VFP, centrifugal pump, and roller pump were performed in a mock circulation study using goat blood. Plasma free hemoglobin was measured every 15 min under the same conditions. The plasma free hemoglobin of the D-VFP was 16 mg/dl although that of the VFP was 160 mg/dl at 30 min. The plasma free hemoglobin of the centrifugal pump and roller pump at 30 min were 3 mg/dl and 9 mg/dl, respectively. The hemolysis performance of the D-VFP may be studied further as a result of this study. Two important factors affecting hemolysis development may be the materials of which the vibrating tube is made and heat transmission from the actuator. The D-VFP has a smooth acrylic surface for blood contact compared with the metal surface of old type VFP. The electromagnetic actuator of the VFP surrounded the vibrating tube, so heat from the actuator could be easily transmitted to the blood. Because the D-VFP has a disposable vibrating tube that is detached from the actuator, heat is not readily transmitted to the blood. A mock circulation study of heat transmission was performed using the D-VFP and VFP. Results of the heat transmission study showed that the fluid temperature of the D-VFP was not increased and stayed at room temperature although that of the VFP increased approximately 1 degrees C above room temperature. The D-VFP may be a good style for the development of the VFP for use for extracorporeal circulation.

  319. Nonlinear mathematical analysis of the hemodynamic parameters during left ventricular assistance with oscillated blood flow Peer-reviewed

    T Yambe, S Kobayashi, T Sonobe, S Naganuma, S Nanka, H Hashimoto, M Yoshizawa, K Tabayashi, H Takayasu, H Takeda, S Nitta

    ARTIFICIAL ORGANS 21 (7) 625-629 1997/07

    Publisher: BLACKWELL SCIENCE INC

    ISSN:0160-564X

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    For the development of a totally implantable ventricular assist system (VAS), we have been developing the vibrating now pump (VFP), which can generate oscillated blood flow with a relatively high frequency (10-50 Hz) for a totally implantable system. In this study, effects of left ventricular assistance with this unique oscillated blood now were analyzed by nonlinear mathematics for evaluation as the entire circulatory regulatory system, not as a separate part of the system. Left heart bypasses using VFPs from the left atriums to the descending aortas were performed in chronic animal experiments using healthy adult goats. Electrocardiogram (EGG), arterial blood pressure, VFP pump flow, and flow of the descending aorta data taken while the goats were awake were recorded in the data recorder and analyzed in the personal computer system through the AD convertor. Using nonlinear mathematics, time series data were embedded into the phase space, and the Lyapunov numerical method, fractal dimension analysis, and power spectrum analysis were performed to evaluate the nonlinear dynamics. During left ventricular assistance with the VFP, Mayer wave fluctuations were decreased in the power spectrum, the fractal dimension of the hemodynamics was significantly decreased, and peripheral vascular resistance was significantly decreased. These results suggest that nonlinear dynamics, which mediate the cardiovascular dynamics, may be affected during LV bypass with oscillated flow. Decreased power of the Mayer wave in the spectrum caused the limit cycle attractor of the hemodynamics and decreased the peripheral resistance. Decreased sympathetic discharges may be the origin of the decreased Mayer wave and fractal dimension. These nonlinear dynamical analyses may be useful to design the optimal VAS control.

  320. Development of intracoronary local adhesive delivery technique. Peer-reviewed

    Sonobe T, Naganuma S, Yambe T, Kobayashi S I, Sizuka K, Katahira Y, Nitta K, Nitta S I

    Int J Artif Organs 20 (6) 319-326 1997/06

  321. The relationship between the arterial inner diameter,the balloon's outer diameter and the volume of infused adhesive, and the evaluation of cases using viscous adhesive in Intracoronary Local Adhesive Delivery Technique

    SONOBE T., YAMABE T., KOBAYASHI S., NANKA S., SHIZUKA K., KAKINUMA Y., NAGANUMA S., KATAHIRA Y., AKIHO H., BAN-NAI H., NAKAMURA Y., NITTA S.

    Journal of the Japanese Society for Artificial Organs and Tissues 26 (2) 498-503 1997/04/15

    Publisher: JAPANESE SOCIETY FOR ARTIFICIAL ORGANS

    DOI: 10.11392/jsao1972.26.498  

    ISSN:0300-0818

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    For the problem of acute coronary occlusion, we designed the intracoronary adhesive delivery technique by which we can form a resinous stent of adhesive on the arterial inner wall with the lesion segment using antithrombotic adhesive and a flexible drug delivery PTCA (Percutaneous Transluminal Coronary Angioplasty) catheter. In this acute animal experiment, using femoral arteries and renal arteries of adult goats in order to ensure the tunnel formation of adhesive, we studied the relationship between the arterial inner diameter, the balloon's outer diameter, and the volume of infused adhesive, and evaluated some cases using the slightly viscous adhesive in this method. When the R, which is the ratio of the arterial inner diameter to the balloon's outer diameter, was within the range of 0.9≤R≤1.0, we could make resinous stents in most cases. In successful cases it seemed that the volume of infused adhesive depends on the arterial stretching degree at the time of adhesive's delivery. That stretching, where that volume is no longer related to the R from the viewpoint of the success or failure of tunnel formation, existed in either cases of the balloon oversize or undersize to the arterial inner diameter. When we used high viscous adhesives, the adhesive's delivery using existing catheters was difficult.

  322. Characterization of renal angiomyolipoma by scanning acoustic microscopy. Peer-reviewed

    Sasaki H, Saijo Y, Tanaka M, Nitta S, Yambe T, Terasawa Y

    J Pathol 181 (4) 455-461 1997/04

    DOI: 10.1002/(SICI)1096-9896(199704)181:4<455::AID-PATH788>3.0.CO;2-J  

  323. Estimation of left ventricular power Peer-reviewed

    M Yoshizawa, A Tanaka, K Abe, H Takeda, Y Kakinuma, H Akiho, T Yambe, S Nitta

    PROCEEDINGS OF THE 19TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY, VOL 19, PTS 1-6 19 251-254 1997

    Publisher: IEEE

    ISSN:1094-687X

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    In the present study, a method for estimating the left ventricular power during one heart beat using the left ventricular pressure and the aortic how has been proposed. The method is based on the beat-by-beat estimation of E-max. In vivo experiments using an adult goat revealed that efficiency of the ventricle as a blood pump could be analysed by using the estimation of the power.

  324. Development and evaluation of totally implantable ventricular assist system using a vibrating flow pump and transcutaneous energy transmission system with amorphous fibers Peer-reviewed

    T Yambe, H Hashimoto, S Kobayashi, T Sonobe, S Naganuma, S Nanka, H Matsuki, M Yoshizawa, K Tabayashi, H Takayasu, H Takeda, S Nitta

    HEART AND VESSELS Suppl 12 41-43 1997

    Publisher: SPRINGER VERLAG

    ISSN:0910-8327

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    We have developed a vibrating flow pump (VFP) that can generate oscillated blood flow with a relatively high frequency (10-50Hz) for a totally implantable ventricular assist system (VAS). To evaluate the newly developed VAS, left heart bypasses, using the VFP, were performed in chronic animal experiments. Hemodynamic parameters were recorded in a data recorder in healthy adult goats during an awake condition and analyzed in a personal computer system through an alternating-direct current converter. Basic performance of the total system with a transcataneous energy transmission system were satisfactory. During left ventricular assistance with the VFP, Mayer wave fluctuations of hemodynamics were decreased in the power spectrum, the fractal dimensions of the hemodynamics were significantly decreased, and peripheral vascular resistance was significantly decreased. These results suggest that cardiovascular regulatory nonlinear dynamics, which mediate the hemodynamics, may be affected by left ventricular bypass with oscillated flow. The decreased power of the Mayer wave in the spectrum caused the Limit cycle attractor of the hemodynamics and decreased peripheral resistance. These results suggest that this newly developed VAS is useful for the totally implantable system with unique characteristics that can control hemodynamic properties.

  325. Extracting 1/f fluctuation from the arterial blood pressure of an artificial heart Peer-reviewed

    T Yambe, SS Nanka, S Naganuma, SI Kobayashi, S Nitta, T Fukuju, M Miura, N Uchida, K Tabayashi, A Tanaka, M Takayasu, K Abe, H Takayasu, M Yoshizawa, H Takeda

    ARTIFICIAL ORGANS 20 (7) 777-782 1996/07

    Publisher: BLACKWELL SCIENCE INC

    ISSN:0160-564X

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    We have studied the fluctuations of an artificial circulation for the analysis of the physiological aspects; however, the conventionally used fast Fourier transform (FFT) method cannot separate harmonic oscillations, such as respiratory and Mayer waves, from the 1/f fluctuation, which has been thought to represent underlying fractal dynamics. Fractal structure was shown in the strange attractor with chaotic dynamics, which is thought to be a flexible and intelligent system. In this study, the coarse-graining spectral analyzing (CGSA) method was utilized to quantitatively evaluate the proportion of the 1/f fluctuation in the total power in the frequency domain and to analyze artificial circulation in the whole system. We implanted two pneumatically actuated ventricular assist devices as biventricular bypasses (BVBs) in chronic animal experiments using 4 healthy adult goats. To compare the natural and prosthetic circulation of each experimental animal, the BVB-type complete prosthetic circulation model with electrically induced ventricular fibrillation was adopted. All hemodynamic parameters of natural and prosthetic circulation were recorded under awake conditions and calculated with the use of a personal computer. With the use of the CGSA method, time-series data of the hemodynamics were analyzed and fractal percentages, extracting the 1/f fluctuation from a given time series, were calculated. Fractal percentages of the arterial blood pressure were 85.8 +/- 10.7% and 82.0 +/- 7.3% with natural and artificial circulation, respectively (not significant [NS]). 1/f fluctuation showed the characteristics of being fractal in a time series, The fractal structure showed robustness and error resistance in nonlinear dynamics, Therefore, our results suggest that the circulatory regulatory system of the artificial heart may have desirable characteristics such as error resistance.

  326. AUTONOMIC NERVOUS SYSTEM EVALUATION DURING LEFT VENTRICULAR ASSISTANCE USING TOTALLY IMPLANTABLE VIBRATING FLOW PUMP.

    YAMBE T., NITTA S., NAGANUMA S., SONOBE T., KAKINUMA Y., AKIHO H., KOBAYASHI S., NANKA S., FUKUJU T., TABAYASHI K., MATSUKI H., HASHIMOTO H., YOSHIZAWA M.

    Journal of the Japanese Society for Artificial Organs and Tissues 25 (3) 744-748 1996/06/15

    Publisher: JAPANESE SOCIETY FOR ARTIFICIAL ORGANS

    DOI: 10.11392/jsao1972.25.744  

    ISSN:0300-0818

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    In order to analyze the autonomic nervous system during left ventricular assistance using oscillated blood flow with Vibrating Flow Pump (VFP), fluctuations of the hemodynamic parameters were evaluated by the fast fourier trasnform with beat-to-beat basis. Chronic animal experiments of the left heart bypass with VFP using four healthy adult goats were performed. Specral analysis of the hemodynamic parameters were performed for the evaluation of the autonomic nervous system. Our results suggest that Mayer wave fluctuations of the hemodynamics were significantly decreased during left heart bypass with VFP, suggesting that sympathetic tone were decreased during left heart bypass with oscillated blood flow.

  327. Fluctuations of the hemodynamic derivatives during left ventricular assistance using oscillated blood flow Peer-reviewed

    T Yambe, S Kobayashi, S Nanka, S Naganuma, S Nitta, H Matsuki, H Abe, M Yoshizawa, T Fukuju, K Tabayashi, H Takeda, H Hashimoto

    ARTIFICIAL ORGANS 20 (6) 637-640 1996/06

    Publisher: BLACKWELL SCIENCE INC

    ISSN:0160-564X

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    To analyze the autonomic nervous system during left heart bypass with a vibrating flow pump (VFP), fluctuations in hemodynamic derivatives were evaluated by the spectral analysis method using fast fourier transform methodology. After the left pleural cavity was opened through the fourth intercostal space under general anesthesia, a VFP was implanted as the left heart bypass device in chronic animal experiments using 3 healthy adult goats. Hemodynamic parameters with and without VFP assistance were recorded on magnetic tape in awake animals and were analyzed by computer through an analog to digital convertor. Power spectral analysis was performed on a beat-to-beat basis for the evaluation of the fluctuations. During left heart bypass with the VFP, Mayer wave fluctuations were decreased significantly although respiratory waves were not changed significantly, These results suggest that sympathetic nervous system modulation was changed under the influences of the left heart bypass with VFP, By using this analysis methodology, truly physiologic ventricular assistance may be achieved.

  328. Spectral analysis of hemodynamics during left ventricular assistance. Peer-reviewed

    Yambe T, Nitta S, Nanka S, Kobayashi S, Naganuma S, Katahira Y, Yoshizawa M, Fukuju T, Uchida N, Tabayashi K

    Int J Artif Organs 19 (6) 367-371 1996/06

  329. Strange hemodynamic attractor parameter with 1/R total artificial heart automatic control algorithm. Peer-reviewed

    Yambe T, Abe Y, Yoshizawa M, Imachi K, Tabayashi K, Takayasu H, Takeda H, Gouhara K, Nitta S

    Int J Artif Organs 19 (5) 302-306 1996/05

  330. DEVELOPMENT OF DISPOSABLE TYPE VFP(VIBRATING FLOW PUMP)FOR ECMO

    NITTA S., KOBAYASHI S., YAMBE T., NAGANUMA S., SONOBE T., KAKINUMA Y., AKIHO H., NANKA S., FUKUJU T., TABAYASHI K., HASHIMOTO H., FUKUTOME A., AOKI M.

    Journal of the Japanese Society for Artificial Organs and Tissues 25 (1) 13-17 1996/02/25

    Publisher: JAPANESE SOCIETY FOR ARTIFICIAL ORGANS

    DOI: 10.11392/jsao1972.25.13  

    ISSN:0300-0818

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    Vibrating flow pump (VFP) was designed as a disposable type blood pump. Basic study of VFP was performed in the mock circulation concerning the effect of the changes of a diameter and length of vibrating tube on pump performance. The pump efficiency was also studied from the point of driving frequency of vibrating tube. To develop VFP as a blood pump for extracorporeal circulation with membrane oxygenator (ECMO), oxygen transport rate during ECMO was evaluated by acute animal experiments using adult goats. From the results of the mock circulation study, pump efficiency showed significant good value in the 15mm diameter of vibrating tube, but no significant change was shown in the length of vibrating tube. Oxygen transport rate of ECMO using VFP was also improved compared with that of the centrifugal pump and air-driven sac type artificial heart. These results indicates that VFP has the advantages in the oxygen transport rate which is important role to develop the ECMO system.

  331. Influence of tissue preparation on the high-frequency acoustic properties of normal kidney tissue Peer-reviewed

    H Sasaki, Y Saijo, M Tanaka, H Okawai, Y Terasawa, T Yambe, S Nitta

    ULTRASOUND IN MEDICINE AND BIOLOGY 22 (9) 1261-1265 1996

    Publisher: PERGAMON-ELSEVIER SCIENCE LTD

    DOI: 10.1016/S0301-5629(96)00150-0  

    ISSN:0301-5629

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    The influence of various tissue preparations on the acoustic properties of normal kidney tissue at high frequencies was investigated. Eight surgically excised normal kidney tissue specimens were classified into three groups: (i) fresh, frozen section, (ii) formalin-fixed, frozen section and (iii) formalin-fixed, paraffin section. Scanning acoustic microscopy operating in the frequency range of 100-200 MHz was used to display the two-dimensional distribution of attenuation constant and sound speed. Our results indicate that (i) there is no significant variation in both acoustic parameters between the three tissue groups, (ii) fixation by 10% formalin produces no significant change in the acoustic parameters, (iii) in fat-free tissue regions, the acoustic parameters are independent of preparation method and (iv) frozen sections must be used to assess the acoustic parameters in fat-rich tissues. Copyright (C) 1996 World Federation for Ultrasound in Medicine & Biology.

  332. A LESS INVASIVE E(MAX) ESTIMATION METHOD FOR WEANING FROM CARDIAC ASSISTANCE Peer-reviewed

    S NITTA, M YOSHIZAWA, T YAMBE, M TANAKA, H TAKEDA

    IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING 42 (12) 1165-1173 1995/12

    Publisher: IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

    DOI: 10.1109/10.476123  

    ISSN:0018-9294

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    The maximum elastance of the ventricle (E(max)) is a strong candidate for a quantitative index used for determination of the timing of weaning the patient from a left ventricular assist device (LVAD), This paper presents a new and less invasive method for deriving E(max) of the left ventricle under the LVAD assistance, In this method (the CoP method), E(max) can be calculated from two different end-systolic points which are produced by changing the drive phase of LVAD without any vascular clamping and any direct measurement of the left ventricular volume, Animal experiments indicated that the CoP method is useful when the measured left ventricular flow and pressure are employed. Moreover, a new technique for estimating the left ventricular flow was developed to make the Cop method less invasive without direct measurement of the flow, The technique could considerably improve the estimation accuracy of the flow in the co-pulsation mode in comparison with the previous one proposed by the authors. However, it has been revealed that the estimation accuracy of the left ventricular flow was not globally high enough to apply the CoP method to clinical cases in spite of its much less invasiveness.

  333. GAS-EXCHANGE EFFICIENCY OF A MEMBRANE-OXYGENATOR WITH USE OF A VIBRATING FLOW PUMP Peer-reviewed

    S NAGANUMA, S NITTA, T YAMBE, S KOBAYASHI, M TANAKA, H HASHIMOTO

    ARTIFICIAL ORGANS 19 (7) 747-749 1995/07

    Publisher: BLACKWELL SCIENCE PUBL INC CAMBRIDGE

    ISSN:0160-564X

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    We have developed a newly designed blood pump, named the vibrating flow pump (VFP), which can generate high frequency oscillated flow. The driving frequency is 10-50 Hz, and flow volume is linearly controlled electric power (current and voltage). The VFP was applied as the pump for extracorporeal circulation (ECC) in acute animal experiments. The gas exchange efficiency of the membrane oxygenator with the VFP and a roller pump (RP) was evaluated. Under general anesthesia with halothane, 7 adult goats underwent ECC; an inflow cannula was inserted into the right atrium, an outflow cannula was sutured to the descending thoratic aorta, and total ECC was performed with a flow of about 80 ml/min/kg. The ECC system with the VFP showed excellent gas exchange efficiency compared with that of the RP. The hemodynamics of ECC using the VFP were easily maintained within normal limits. These results suggest that the VFP is very useful as a pump for ECC; thus, a compact-sized ECC system may be achieved.

  334. FRACTAL DIMENSION ANALYSIS OF THE OSCILLATED BLOOD-FLOW WITH A VIBRATING FLOW PUMP Peer-reviewed

    T YAMBE, T SONOBE, S NAGANUMA, S KOBAYASHI, S NANKA, H AKIHO, Y KAKINUMA, M MITSUOKA, S CHIBA, N OHSAWA, Y HAGA, K IDUTSU, S NITTA, T FUKUJU, M MIURA, N UCHIDA, N SATO, K TABAYASHI, A TANAKA, N YOSHIZUMI, K ABE, M TAKAYASU, H TAKAYASU, M YOSHIZAWA, T MAEKAWA, H HASHIMOTO

    ARTIFICIAL ORGANS 19 (7) 729-733 1995/07

    Publisher: BLACKWELL SCIENCE PUBL INC CAMBRIDGE

    ISSN:0160-564X

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    To analyze the hemodynamic parameters during circulation with oscillated blood flow, nonlinear mathematical analyzing techniques, including fractal theory, were utilized, Vibrating flow pumps (VFP) were implanted as a left heart bypass, and the ascending aorta was clamped to constitute the total left heart circulation with oscillated blood flow in acute animal experiments using 7 adult goats. Using nonlinear mathematical analyzing techniques, reconstructed attractors of the arterial blood pressure waveform in the phase space during natural circulation and oscillated circulation were analyzed, Using the Grassberger-Procaccia correlation dimension analyzing technique, fractal dimension analysis of the reconstructed attractor was performed. During VFP bypass, lower fractal dimensions of the reconstructed attractor were shown compared with those during natural heart circulation. The results suggest that lower dimensional chaotic dynamics contributed to the circulation with oscillated blood flow.

  335. EXPERIMENTAL-STUDY OF PHYSIOLOGICAL ADVANTAGES OF ASSIST CIRCULATION USING OSCILLATED BLOOD-FLOW Peer-reviewed

    S KOBAYASHI, S NITTA, T YAMBE, S NAGANUMA, H HASHIMOTO, T FUKUJU, K TABAYASHI

    ARTIFICIAL ORGANS 19 (7) 704-707 1995/07

    Publisher: BLACKWELL SCIENCE PUBL INC CAMBRIDGE

    ISSN:0160-564X

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    To estimate the effect of oscillated blood flow on hemodynamics in an awake condition, left ventricular assist circulation using oscillated blood flow was performed on 3 adult goats as chronic animal examination. A vibrating flow pump (VFP) was used for generating high-frequency oscillated flow. The blood flow rate of assisted circulation was approximately 1.0 L/min, and the driving frequency of VFP was 25 Hz. Systemic vascular resistance and arterial impedance were calculated in this study. Systemic vascular resistance during assist circulation was decreased compared with that without assistance. Oscillated blood flow may be effective in decreasing vascular resistance. Moreover, it was suggested from the study of arterial impedance that motive characteristics of the vascular wall against changing blood pressure may keep their normal reaction. Therefore, oscillated blood flow may be used for left ventricular assist circulation as concluded from the study of the characteristics of blood vessels.

  336. TOTALLY IMPLANTABLE VENTRICULAR ASSIST SYSTEM USING A VIBRATING FLOW PUMP Peer-reviewed

    S NITTA, T YAMBE, T SONOBE, S NAGANUMA, Y KAKINUMA, S KOBAYASHI, M TANAKA, H MATSUKI, K ABE, M YOSHIZAWA, T KASAI, H HASHIMOTO

    ARTIFICIAL ORGANS 19 (7) 676-679 1995/07

    Publisher: BLACKWELL SCIENCE PUBL INC CAMBRIDGE

    ISSN:0160-564X

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    A totally implantable ventricular assist system (VAS), including a drive system and a percutaneous electric energy transmission system, was developed and evaluated in acute animal experiments using adult goats. This newly designed VAS mainly consists of a vibrating tube, coils, magnets, and a jelly-fish valve as the outlet valve. For energy transmission, a new implantable transmitter with a plain weave structure was proposed as a noncontacting transform by using the spinal amorphous magnetic fibers. The fluid mechanical and hemodynamic properties and the efficiency of the energy transmission system were evaluated in acute animal experiments using healthy adult goats. This vibrating electromagnetic artificial heart (AH) could generate more than 10 L/min as output volume, with 10 Hz vibration using 20 volts as supplied voltage. The total efficiency of the percutaneous energy transmission system was 76%, and temperature increases were within the acceptable range, suggesting the usefulness of our newly developed implantable VAS.

  337. FRACTAL DIMENSION ANALYSIS OF THE HEMODYNAMICS WITH ARTIFICIAL HEART

    YAMBE T., NANKA S., SONOBE T., NAGANUMA S., KAKINUMA Y., KOBAYASHI S., AKIHO H., IDUTSU K., NAGANUMA T., OHSAWA N., NITTA S., FUKUJU T., MIURA M., SATO N., UCHIDA N., TABAYASHI K., TANAKA A., YOSHIZUMI N., ABE K., TAKEDA H., TAKAYASU H., YOSHIZAWA M.

    Journal of the Japanese Society for Artificial Organs and Tissues 24 (3) 852-857 1995/06/15

    Publisher: JAPANESE SOCIETY FOR ARTIFICIAL ORGANS

    DOI: 10.11392/jsao1972.24.852  

    ISSN:0300-0818

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    In order to analyze the hemodynamic properties during total artificial circulation as an entity, not as the decomposed parts, nonlinear mathematical analyzing technique including fractal theory was utilized in the chronic animal experiments using healthy adult goats. For the comparison between the natural & artificial circulation, biventricular bypass type total artificial circulation model was adopted. In the awake condition, hemodynamic time series data without ventricular assistance was recorded for the control study. After that, ventricular fibrillation was induced electrically and biventricular bypass (BVB) pump was started to constitute the BVB type complete prosthetic circulation model. Correlation dimension analysis of the hemodynamics revealed the fact that time series data of the arterial blood pressure may be fractal time series data even during artificial circulation, suggesting the possibility that artificial heart may be able to make the flexible and robust system by the achievement of fractal dynamics.

  338. CLINICAL APPLICATION OF TH-7 VENTRICULAR ASSIST DEVICE

    NITTA S., YAMBE T., KAKINUMA S., KAKINUMA Y., AKIHO H., IDUTSU K., KOBAYASHI S., NANKA S., FUKUJU T., MIURA M., UCHIDA N., TABAYASHI K., FUKUTOME A., MOIZUMI Y.

    Journal of the Japanese Society for Artificial Organs and Tissues 24 (2) 265-270 1995/04/15

    Publisher: JAPANESE SOCIETY FOR ARTIFICIAL ORGANS

    DOI: 10.11392/jsao1972.24.265  

    ISSN:0300-0818

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    An newly developed total VAD, which is more practical and proper for mass-production, have been evaluated. This new VAD system is parted into the sac and outer case, inflow and outflow cannulae, and their prosthetic valve built in connectors. Therefore, when we find the partial accident in VAD system, we can exchange only the accidental part. Durability test in the mock circulation and chronic animal experiments using adult goats were performed. THe results show that our VAD system has good property of hydrodynamics and antithrombogenecity and durability. We conclude that our VAD system can be useful for clinical application.

  339. Can the artificial heart make the circulation become fractal? Peer-reviewed

    Yambe T, Nanka S, Naganuma S, Kobayashi S, Akiho H, Kakinuma Y, Ohsawa N, Nitta S, Fukuju T, Miura M

    Int J Artif Organs 18 (4) 190-196 1995/04

  340. CGSA法による補助人工心臓使用下における循環動態の非線形解析

    南家 俊介, 山家 智之, 薗部 太郎, 永沼 滋, 小林 信一, 秋保 洋, 柿沼 義人, 仁田 新一, 福寿 岳雄, 三浦 誠, 内田 直樹, 田林 晄, 吉澤 誠

    人工臓器 24 S159a-S159a 1995

    Publisher: JAPANESE SOCIETY FOR ARTIFICIAL ORGANS

    DOI: 10.11392/jsao1972.24.Supplement_S159a  

    ISSN:0300-0818

  341. Deterministic chaos in the hemodynamics of an artificial heart Peer-reviewed

    Tomoyuki Yambe, Shin ichi Nitta, Taro Sonobe, Shigeru Naganuma, Yoshito Kakinuma, Kenji Izutsu, Hiroshi Akiho, Shin ichi Kobayashi, Noboru Ohsawa, Shunsuke Nanka, Motonao Tanaka, Takeo Fukuju, Makoto Miura, Naok Uchida, Naoshi Sato, et. al.

    ASAIO Journal 41 (1) 84-88 1995/01

    Publisher: J.B. Lippincott Co

    DOI: 10.1097/00002480-199501000-00014  

    ISSN:1058-2916

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    The hemodynamic parameters that occur during prosthetic circulation are analyzed as an entity using non linear mathematical techniques. For purposes of comparing natural and prosthetic circulation, two pneumatically actuated ventricular assist devices were implanted as ventricular bypasses in several experiments using goats. All hemodynamic parameters were recorded during awake conditions. Arterial blood pressure waveform was embedded into a four dimensional space and then projected into a three dimensional phase space. Analysis of the state phase showed the incidence of deterministic chaos during natural circulation, however during artificial circulation a simple tractor was observed. These results suggest that hydrodynamic parameters must be controlled during prosthetic circulation when unexpected stimuli are fed from the outside.

  342. Chaotic behavior of hemodynamics with ventricular assist system. Peer-reviewed

    Yambe T, Nanka S, Sonobe T, Naganuma S, Kobayashi S, Akiho H, Kakinuma Y, Mitsuoka M, Chiba S, Ohsawa N

    Int J Artif Organs 18 (1) 17-21 1995/01

  343. [Two cases of malignant effusion treated successfully by loco-regional administration of carboplatin] Peer-reviewed

    Takahashi J, Kinomura S, Abe Y, Yoshioka S, Yambe T, Ono S, Ito H, Fukuda H, Yamada K, Sato T

    Gan To Kagaku Ryoho 21 (16) 2817-2820 1994/12

  344. FLUCTUATIONS OF THE SYMPATHETIC-NERVE DISCHARGES IN ANIMALS WITHOUT NATURAL HEARTBEAT Peer-reviewed

    T YAMBE, S NITTA, S NAGANUMA, Y KAKINUMA, K ZUTSU, H AKIHO, T NAGANUMA, Y KIKUCHI, S KOBAYASHI, N OHSAWA, S NANKA, M TANAKA, T FUKUJU, M MIURA, N UCHIDA, N SATO, H MOHRI, S KOIDE, K ABE, H TAKEDA, M YOSHIZAWA

    ARTIFICIAL ORGANS 18 (10) 775-780 1994/10

    Publisher: BLACKWELL SCIENCE INC

    ISSN:0160-564X

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    To assess the effect of artificial circulation on the circulatory regulatory system, rhythmical fluctuations in the cardiovascular system and autonomic nerve discharges were analyzed in animal experiments using adult mongrel dogs. Two pneumatically actuated ventricular assist devices were implanted as total biventricular bypass (BVB) under general anesthesia; then, the natural heart was electrically fibrillated to constitute the BVB part of the complete prosthetic circulation model. All hemodynamic data and sympathetic nerve discharges were recorded and calculated in the computer system by the use of spectral analyzing methods. In the power spectrum of the arterial blood pressure waveform during prosthetic circulation, the Mayer wave peak was significantly decreased though the respiratory wave peak was not significantly changed. However, the Mayer wave peak in sympathetic nerve discharges was significantly increased though the respiratory wave peak was not significantly changed. These results suggest that rhythmical fluctuations are a necessary response of the circulatory regulatory system including the autonomic nervous system. However, sympathetic nerve discharges respond to the artificial heart without rhythmical fluctuations.

  345. CHAOTIC HEMODYNAMICS DURING OSCILLATED BLOOD-FLOW Peer-reviewed

    T YAMBE, S NITTA, T SONOBE, S NAGANUMA, Y KAKINUMA, S KOBAYASHI, M TANAKA, T FUKUJU, M MIURA, N SATO, H MOHRI, S KOIDE, H TAKEDA, M YOSHIZAWA, T KASAI, H HASHIMOTO

    ARTIFICIAL ORGANS 18 (9) 633-637 1994/09

    Publisher: BLACKWELL SCIENCE INC

    ISSN:0160-564X

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    A vibrating flow pump (VFP), which can generate oscillated blood flow (10-50 Hz/min), has been developed by our team for the artificial heart system. However, the flow pattern of this pump was different from that of the natural heart; therefore, it is important to analyze the effect of this oscillated blood flow on the circulatory regulatory system. To analyze the hemodynamics of high frequency oscillated blood flow as an entity, (not decomposed), nonlinear mathematical techniques were utilized. VFPs were implanted between the left atrium in animal experiments using adult goats. After the implantation procedure, the ascending aorta was clamped to constitute the complete left heart circulation with VFP. Using a nonlinear mathematical technique, an arterial blood pressure waveform was embedded into four-dimensional phase space and projected into three-dimensional phase space. The Lyapunov numerical method was used as an adjunct to graphic analysis of the state space. Phase portrait of the attractor showed a high dimension complex structure, suggesting deterministic chaos during natural circulation. However, phase portrait of the hemodynamics during oscillated blood flow showed a single circle with banding and a forbidden zone, similar to a limit-cycle attractor, suggesting a lower dimensional dynamic system. Positive Lyapunov exponent during oscillated blood flow suggests the existence of lower dimensional chaotic dynamics. These results suggest that the circulatory regulatory system during oscillated blood flow may be a lower dimensional homeochaotic state; thus, hemodynamic parameters must be carefully regulated when unexpected external stimuli are present.

  346. CAROTID ARTERIAL IMPEDANCE DURING OSCILLATED BLOOD-FLOW Peer-reviewed

    S KOBAYASHI, S NITTA, T YAMBE, S NAGANUMA, M TANAKA, T KASAI, H HASHIMOTO

    ARTIFICIAL ORGANS 18 (9) 627-632 1994/09

    Publisher: BLACKWELL SCIENCE INC

    ISSN:0160-564X

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    Blood perfusion of systemic circulation is influenced by the physical characteristics of artery. Several investigations proposed that the physical parameters of vessels are determined by neurological factors, hormonal factors, and physical properties of arteries among others. In this study, arterial impedance was estimated because it may express the condition of vessels. To examine the change of arterial impedance according to the blood flow pattern, the typical sine wave blood flow (oscillated flow) was used during total cardiopulmonary bypass (CPB) because it is considered the most simple pulsatile flow. CPB using oscillated blood flow was performed in acute experiments on adult goats. Total systemic flow was controlled to remain at approximately 80 ml/min. Carotid arterial flow, aortic pressure, central venous pressure, and systemic flow were measured. Total peripheral resistance, carotid arterial resistance, systemic impedance, and carotid arterial impedance were calculated to evaluate blood flow distribution during CPB. This study suggested that the parameters of carotid arterial blood flow changed according to the change of flow frequency during oscillated blood flow. This change may occur because arterial impedance was influenced by flow frequency; therefore, the blood flow of the carotid artery was significantly changed according to the change of the frequency component of blood flow.

  347. 左心補助人工心臓の駆動時相変化による大動脈インピーダンスの検討

    秋保 洋, 仁田 新一, 山家 智之, 永沼 滋, 柿沼 義人, 井筒 憲司, 小林 信一, 南家 俊介, 田中 元直, 福寿 岳雄, 三浦 誠, 佐藤 尚, 田林 胱一, 小出 訓, 吉澤 誠, 阿部 健一

    人工臓器 23 S54a-S54a 1994

    Publisher: JAPANESE SOCIETY FOR ARTIFICIAL ORGANS

    DOI: 10.11392/jsao1972.23.Supplement_S54a  

    ISSN:0300-0818

  348. Arterial impedance during the cardiopulmonary bypass using oscillated blood flow.

    KOBAYASHI S, NITTA S, YAMBE T, SONOBE T, NAGANUMA S, TANAKA M, FUKUJU T, MOURI H, KASAI T, HASHIMOTO H

    Journal of the Japanese Society for Artificial Organs and Tissues 23 (1) 336-341 1994

    Publisher: JAPANESE SOCIETY FOR ARTIFICIAL ORGANS

    DOI: 10.11392/jsao1972.23.336  

    ISSN:0300-0818

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    The blood perfusion of systemic circulation is influenced by the physical characteristics of artery. Several investigations proposed that the physical parameters of vessels are determined by some factors which are neurological factors, hormonal factors, physical properties of artery and so on. In this study, the arterial impedance was estimated because it may express the conditions of vessels. To examine the change of arterial impedance according to the blood flow pattern, the typical sine-wave blood flow, which was called oscillated flow, was used for the total cardiopulmonary bypass (CPB), because it can be considered for the most simple pulsatile flow. CPB using oscillated blood flow was performed for eight adult goats in acute experiments. The total systemic flow were controlled to maintain about 80ml/min. Aortic pressure, central venous pressure and systemic flow were measured. And the total peripheral resistance and arterial impedance were calculated to evaluate the reaction of vessels during the CPB. From this study, it was shown that arterial impedance was fluctuated according to the change of flow frequency. So the vascular reaction to the change of blood flow velocity might be characterized during oscillated blood flow.

  349. Effect of left ventricular assist on oxygen consumption in recovery period after transient myocardial ischemia.

    KAKINUMA Y., NITTA S., YAMBE T., SONOBE T., NAGANUMA S., AKIHO H., IDUTSU K., KOBAYASHI S., NANKA S., TANAKA M., FUKUJU T., MIURA M., SATO N., MOURI H., KOIDE S., TAKEDA H., KASAI T., YOSHIZAWA M.

    Journal of the Japanese Society for Artificial Organs and Tissues 23 (3) 904-910 1994

    Publisher: JAPANESE SOCIETY FOR ARTIFICIAL ORGANS

    DOI: 10.11392/jsao1972.23.904  

    ISSN:0300-0818

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    To analyze the effect of left ventricular assist (LV-assist) on the stunned myocardium, acute animal experiments using 4 adult goats with LV-assistt were carried out using the model of transient ischemia ligating the left anterior descending coronary artery. In this study, the pressure-volume area (PVA) according with oxygen-consumption and the external cardiac work (EW) were calculated using pressure-volume loop (P-V loop), with and without LV-assist. EW during LV-assist significantly decreased, compared with EW without LV-assist. However PVA did not significantly change with and without LV-assist. These results suggested that the decrease in EW contributed to the early recovery from stunned myocardium.

  350. Use of fuzzy clustering techniques Peer-reviewed

    Makoto Yoshizawa, Hiroshi Tokeda, Tomoyuki Yambe, Shin-Ichi Nitta

    IEEE Engineering in Medicine and Biology Magazine 13 (5) 687-692 1994

    DOI: 10.1109/51.334630  

    ISSN:0739-5175

  351. LESS-INVASIVE E(MAX) ESTIMATION UNDER CARDIAC ASSISTANCE BASED ON ANGULAR FREQUENCY METHOD Peer-reviewed

    M YOSHIZAWA, K ABE, D SATO, H TAKEDA, T YAMBE, S NITTA

    PROCEEDINGS OF THE 16TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY - ENGINEERING ADVANCES: NEW OPPORTUNITIES FOR BIOMEDICAL ENGINEERS, PTS 1&2 107-108 1994

    Publisher: I E E E

  352. Chaotic attractor of the left ventricular wall motion in normal heart healthy subject Peer-reviewed

    T. Yambe, S. Nitta, T. Naganuma, Y. Saijoh, S. Naganuma, S. Kobayashi, M. Tanaka, M. Yoshizawa

    Journal of Cardiology 24 (6) 469-474 1994

    ISSN:0914-5087

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    To analyze the entire left ventricular wall motion, not the decomposed motion, nonlinear mathematical techniques were used to describe graphically time series data for the left ventricular contraction. Time series data of the left ventricular wall motion were recorded by M-mode echocardiography, and embedded into three-dimensional phase space. The largest Lyapunov exponents, a measure of the rate of divergence in phase space, were calculated to detect the sensitive dependence on initial conditions. The reconstructed attractor of the left ventricular contraction showed a lower dimensional strange attractor, and calculation of the Lyapunov exponents indicated sensitivity to initial conditions. These results suggest that time series data of the left ventricular contraction show the characteristics of deterministic chaos. The chaotic system can provide an intelligent and flexible control system. Our results suggest that the circulatory control system, which mediates the cardiac contractility, may be a flexible dynamic compatible with deterministic chaos.

  353. ORIGIN OF THE RHYTHMICAL FLUCTUATIONS IN THE ANIMAL WITHOUT A NATURAL HEARTBEAT Peer-reviewed

    T YAMBE, S NITTA, T SONOBE, S NAGANUMA, Y KAKINUMA, S KOBAYASHI, S NANKA, N OHSAWA, H AKIHO, M TANAKA, T FUKUJU, M MIURA, N UCHIDA, N SATO, H MOHRI, S KOIDE, K ABE, H TAKEDA, M YOSHIZAWA

    ARTIFICIAL ORGANS 17 (12) 1017-1021 1993/12

    Publisher: BLACKWELL SCIENCE INC

    ISSN:0160-564X

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    In order to analyze the origin of the rhythmical fluctuations in the cardiovascular system, an artificial heart, which does not have rhythmical periodicities such as altering heart rate and cardiac function, was utilized in chronic animal experiments with adult goats. Two pneumatically actuated ventricular assist devices were implanted as a total biventricular bypass under general anesthesia, and then the natural heart was electrically fibrillated to constitute the biventricular bypass type of complete prosthetic circulation model. All hemodynamic data were recorded under awake conditions and were calculated in the computer system by spectral analysis methods. In the power spectrum of the arterial blood pressure of the animal with the artificial heart, the Mayer wave peak and respiratory wave peak were clearly observed, and spectral analysis including the coherence function suggests that the Mayer waves originated from the peripheral vascular resistance and the respiratory waves probably originated from the periodicities of the pulmonary circulation. These fluctuations in the circulatory system influenced the arterial baroreflex system and transfer to the sympathetic outflow through the central baroreflex system, which suggests that rhythmical fluctuations in hemodynamic parameters originate at least in part from these vascular periodicities.

  354. Identification of the deterministic chaos in cardiovascular dynamics by the use of the non-linear mathematics. Peer-reviewed

    Yambe T, Nitta S, Sonobe T, Naganuma S, Kobayashi S, Haga Y, Tanaka M, Fukuju T, Miura M, Sato N

    Sci Rep Res Inst Tohoku Univ [Med] 39 (1月4日) 1-5 1993/12

  355. Differentiation of transiently ischemic from infarcted myocardium by Thallium-201 exercises scintigram after active ergometer rehabilitation Peer-reviewed

    Tomoyuki Yambe, Shin-ichi Nitta, Motonao Tanaka, Tai-ichiroh Meguro, Yoshifumi Saijoh, Shigeru Naganuma, Shin-ichi Kobayashi, Norio Endoh, Yoshio Terasawa, Yoshiaki Katahira, Taroh Sonobe, Keiko Nitta, Hisanao Takeda, Kazuhiko Takahashi, Yoshihisa Shimanuki, Hisao Itoh

    Annals of Nuclear Medicine 7 (3) 187-192 1993/09

    DOI: 10.1007/BF03164965  

    ISSN:0914-7187 1864-6433

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    It has been frequently reported that while myocardial viability is neglected in conventional methods of diagnosis such as left ventriculography, ECG, and exercise thallium-201 myocardial scintigraphy (Ex-Tl), revascularization often results in improving left ventricular wall motility. In the present study, the authors contrived a method to accurately evaluate the viability ot the myocardium by means of exercise rehabilitation, and tested the method in clinical cases. Among patients with myocardial infarction, we selected a patient with negative viability in the diseased area as determined by chronic ECG, left ventriculography (LVG), coronary angiography and Ex-Tl. This patient went through two weeks of active exercise rehabilitation gauged with an ergometer, and was then re-examined by Ex-Tl. After the evaluation, revascularization was performed for the patient who demonstrated viability of the infarcted myocardium in EX-T1 after rehabilitation, and significant improvement in contractility was shown in the chronic LVG. These findings indicate that our method of detecting potential viability of the infarcted myocardium is of clinical significance. © 1993 Springer-Verlag.

  356. REAL-TIME CARDIAC-OUTPUT ESTIMATION OF THE CIRCULATORY-SYSTEM UNDER LEFT-VENTRICULAR ASSISTANCE Peer-reviewed

    M YOSHIZAWA, H TAKEDA, M MIURA, T YAMBE, Y KATAHIRA, S NITTA

    IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING 40 (3) 266-275 1993/03

    Publisher: IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

    DOI: 10.1109/10.216410  

    ISSN:0018-9294

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    A new method for indirect and real-time estimation of the cardiac output of the circulatory system supported by the left ventricular assist device (LVAD) was proposed. This method has low invasiveness and is useful for clinical application of the LVAD since it needs only two measurements: the outflow rate of blood from the LVAD and the aortic pressure. The proposed method is based on a system identification technique for the time series model of the cardiovascular system and requires less computational time than other methods with similar estimation accuracy. Hence, the proposed method could be implemented in a personal computer system and realize the on-line and real-time estimation of the instantaneous outflow rate of the natural heart. The efficiency and limitation of the method were discussed on the basis of the results obtained from in vitro experiment using a mock circulatory system and in vivo experiment using an adult goat. It was revealed that the method could obtain a fairly high correlation coefficient between the true stroke volume of the natural heart and its estimate of more than 0.99 (in vitro) or 0.95 (in vivo). This means that there is a fair possibility of applying the proposed estimation system to the clinical use.

  357. Mayer waves in the sympathetic nerve activity of the animal with total artificial heart.

    YAMBE T, NITTA S, TANAKA M, MOHRI H, YOSHIZAWA M, KOIDE S, ABE K, TAKEDA H

    Journal of the Japanese Society for Artificial Organs and Tissues 22 (5) 1228-1232 1993

    Publisher: JAPANESE SOCIETY FOR ARTIFICIAL ORGANS

    DOI: 10.11392/jsao1972.22.1228  

    ISSN:0300-0818

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    In order to evaluate the effect of total artificial heart replacement on autonomic nervous system, power spectrum analysis of the hemodynamic parameters and sympathetic nerve activity in TAH animal was performed using the fast Fourier transform and maximum entropy methods. Two pneumatically actuated sac type ventricular assist devices were connected as biventricular bypass (BVB) in 7 mongrel dogs, and sympathetic outflow were recorded at the renal sympathetic nerve. After the BVB pumping, natural heart was electrically fibrillated to constitute a BVB type of TAH model. In arterial pressure waveform of the animal with TAH, respiratory waves were not significantly changed, though Mayer waves were significantly decreased compared with that of natural heart. And Mayer wave fluctuation were significantly increased during prosthetic circulation. These results suggest that autonomic nervous system want to increase the Mayer wave component in the hemodynamic<br>parameters during artificial circulation.

  358. Simulation study on control algorithm of artificial heart using peripheral vascular resistance.

    HIROSHI H., YOSHIZAWA M., TAKEDA H., YAMBE T., NITTA S.

    Journal of the Japanese Society for Artificial Organs and Tissues 22 (3) 724-729 1993

    Publisher: JAPANESE SOCIETY FOR ARTIFICIAL ORGANS

    DOI: 10.11392/jsao1972.22.724  

    ISSN:0300-0818

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    To control the total artificial heart on the basis of the autonomic nervous system information, Abe proposed a control algorithm in which the cardiac output is controlled so as to be proportional to the reciprocal of the peripheral vascular resistance. The present study has investigated the adequacy of Abe's control algorithm by digital simulation using the cardiovascular model. It has been concluded that Abe's control strategy can be regarded as a kind of decoupling control algorithm if the cardiovascular system is considered to be a two-input two-output system, while the theoretical method for obtaining a tuning parameter included in his strategy has not been explained.

  359. DEPENDENCE OF BARORECEPTOR-MEDIATED SYMPATHETIC OUTFLOW ON BIVENTRICULAR ASSIST DEVICE DRIVING FREQUENCY Peer-reviewed

    T YAMBE, S NITTA, Y KATAHIRA, T SONOBE, S NAGANUMA, Y KAKINUMA, H AKIHO, K IZUTSU, Y KIKUCHI, M TANAKA, M MIURA, N SATO, H MOHRI, M YOSHIZAWA, K IZUMI, H TAKEDA

    ARTIFICIAL ORGANS 17 (1) 18-23 1993/01

    Publisher: BLACKWELL SCIENCE INC

    ISSN:0160-564X

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    To investigate the drive condition of the artificial heart from a neurophysiological point of view, the dynamic transduction characteristics of the baroreflex system were analyzed by means of sympathetic neurograms. Two pneumatically actuated ventricular assist devices were implanted as biventricular bypasses (BVBs) in adult mongrel dogs to compare the natural heart circulation and prosthetic circulation. After BVB pumping was initiated, the natural heart was electrically fibrillated. Renal sympathetic nerve activity (RSNA) was recorded to analyze sympathetic outflow. Coherence function between the arterial pressure and RSNA was calculated to evaluate the linearity of the baroreflex system. The largest peak coherency was observed when BVB was driven at the frequency of natural heart beat prior to electrical fibrillation, which suggests that the baroreflex system shows the largest linearity at this frequency. These results suggest the possibility that the natural heart beat frequency is the setting frequency at which the baroreflex system transfers the hemodynamic rhythm to the sympathetic outflow.

  360. Estimation of the following cardiac output using sympathetic tone and hemodynamics for the control of a total artificial heart. Peer-reviewed

    Yambe T, Nitta S, Katahira Y, Sonobe T, Naganuma S, Akiho H, Kakinuma Y, Izutzu K, Kikuchi Y, Naganuma T

    Int J Artif Organs 15 (10) 606-610 1992/10

  361. Mayer waves in dogs with total artificial heart. Peer-reviewed

    Yambe T, Nitta S, Katahira Y, Sonobe T, Naganuma S, Kakinuma Y, Kobayashi S, Tanaka M, Miura M, Sato N

    Int J Artif Organs 15 (10) 601-605 1992/10

  362. AN AUTOMATIC-CONTROL ALGORITHM FOR THE OPTIMAL DRIVING OF THE VENTRICULAR-ASSIST DEVICE Peer-reviewed

    M YOSHIZAWA, H TAKEDA, T WATANABE, M MIURA, T YAMBE, Y KATAHIRA, S NITTA

    IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING 39 (3) 243-252 1992/03

    Publisher: IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

    DOI: 10.1109/10.125009  

    ISSN:0018-9294

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    This paper presents a new method of keeping one of the most suitable driving conditions for regulating the outflow volume from the ventricular-assist device (VAD). The experimental results from a mock circulatory system have shown that the relationship between the stroke volume and the systolic duration of the VAD can be specified by the combination of characteristic curves of the positive and negative drive pressures. The optimal operating point on the characteristic curve have been defined as the point at which thrombosis on the blood-contacting surface and hemolysis due to mechanical damage can be avoided and at which the driving energy can be minimized. The present analysis has been revealed that the optimal operating point is the vertex of the triangular figure obtained from the characteristic curve. The algorithms for keeping the optimal operating point and for regulating the stroke volume have been also proposed.

  363. Monitoring and Estimation Tool for the Control System of Ventricular Assist Device Using Fuzzy Reasoning

    Yoshizawa Mokoto, Takeda Hiroshi, Miura Makoto, Yambe Tomoyuki, Katahira Yoshiaki, Nitta Shin-ichi

    Proceedings of the Annual Meeting of Biomedical Fuzzy Systems Association : BMFSA 4 117-126 1992

    Publisher: Biomedical Fuzzy Systems Association

    DOI: 10.24466/bmfsa.4.0_117  

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    An automatic, on-line and real-time monitoring and estimation system (TOTOMES; Tohoku University and Toyohashi University of Technology, monitioring and estimation system) for the cardiovascular dynamics under left ventricular assist device (LVAD) pumping has been developed to unload the operator who has to pay constant attention to the LVAD operation. The TOTOMES has the function which detects the presence and origin of accidents happening in the cardiovascular system, the pneumatic drive unit as well as the automatic controller. Detection of the malfunction is realized by using fuzzy reasoning. The combination of several measurements and estimates included in the antecedent of the fuzzy rules enables us to distinguish the origin of the malfunction. In in vivo experiment using an adult goat, it was ascertained that the proposed system successfully worked when the inlet cannula resistance was suddenly changed by clamping and when the blood withdrawing was carried out.

  364. Effect of left ventricular assistance on the induced stunned myocardium.

    KAKINUMA Y, NITTA S, KATAHIRA Y, YAMBE T, SONOBE T, NAGANUMA S, AKIHO H, IZUTU K, KIKUCHI Y, TANAKA M, MIURA M, SATOH N, MOHRI H, IZUMI K, TAKEDA H, YOSHIZAWA M

    Journal of the Japanese Society for Artificial Organs and Tissues 21 (2) 405-408 1992

    Publisher: JAPANESE SOCIETY FOR ARTIFICIAL ORGANS

    DOI: 10.11392/jsao1972.21.405  

    ISSN:0300-0818

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    In order to evaluate the effect of left ventricular assistance on cardiac dysfunction due to the induced stunned myocardium after the reperfusion, acute experiments using adult goats was performed. After the implantation of our TH-7B pneumatically driven VAD as left heart bypass, left anterior discending artery (LAD) was reperfused after short time occulusion to constitute the model of the stunned myocardium. Pressure-Volume curve (P-V curve) and E<sub>max</sub> of left ventricle were obtained by our newly developed automatic hemodynamics analysing system to evaluate the recovery time from the transient left ventricular dysfunction. The recovery time were significantly decreased by the use of VAD. These results suggest that VAD is useful also for the transient ischemia to avoid to have heart muscle destroyed.

  365. A coherence spectral analysis between heart rate variability and blood pressure fluctuation under left ventricular assistance.

    KATAHIRA Y, NITTA S, YAMBE T, IZUMI K, SONOBE T, NAGANUMA S, AKIHO H, KAKINUMA Y, MATSUZAWA H, IZUTSU K, SATOH N, MIURA M, MOHRI H, YOSHIZAWA M, TAKEDA H, TANAKA M

    Journal of the Japanese Society for Artificial Organs and Tissues 21 (2) 477-483 1992

    Publisher: JAPANESE SOCIETY FOR ARTIFICIAL ORGANS

    DOI: 10.11392/jsao1972.21.477  

    ISSN:0300-0818

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    The purpose of this study is to identify the participation of the blood pressure to the heart rate variability which reflects the autonomic nerve response to the systemic ventricular assistance. For this purpose, the coherence of the blood pressure fluctuation against the heart rate was analyzed in long-term animal experiments using adult goats under the ventricular assistance of different driving modes. A high coherence was observed in 0.1Hz (Mayer wave) and 0.3 Hz (respiratory arrhythmia) under both synchronous and asynchronous modes. Especially, the coherence of systolic and pulse blood pressure was very high. The coherence of blood pressure against the heart rate reflects the participation of the blood pressure to the autonomic cardiovascular control mechanism. Therefore, this evidence indicates that the blood pressure has an influence on the autonomic nervous system which oscillates the heart rate. In addition, the power spectrum of systemic resistance, calculated from the cardiac output and the blood pressure, had only one spectral peak (0.05Hz) with high coherence against heart rate and blood pressure. It was concluded that the coherence spectral analysis could reveal the mechanism of the heart rate variability under ventricular assistance and furnish useful information concerning the driving mode of the ventricular assistance.

  366. Effect of high frequent vibrating blood flow on the peripheral blood flow distribution using a viblating electro-magnetic pump(VEMP) in the condition of hypoperfusion.

    SONOBE T, NITTA S, KATAHIRA Y, YAMBE T, MATUZAWA H, NAGANUMA S, KAKINUMA Y, AKIHO H, IZUTU K, SUGAWARA S, TANAKA M, MIURA M, SATOH N, MOHRI H, KASAI T, HASHIMOTO H, YOSHIZAWA M.

    Journal of the Japanese Society for Artificial Organs and Tissues 21 (2) 464-471 1992

    Publisher: JAPANESE SOCIETY FOR ARTIFICIAL ORGANS

    DOI: 10.11392/jsao1972.21.464  

    ISSN:0300-0818

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    A viblating electro-magnetic pump (VEMP), which generates viblating flow at the frequency of 3-50Hz, was utilized to analyse the effect of each frequency element composing the pulsatile flow and pressure patterans on the peripheral blood flow distribution in the condition of hypoperfusion. In 7 adult goats in which a VEMP was applied as a total left heart bypass, carotid artery flow (CAF), subclavian artery flow and total peripheral resistance were changed according to the drive frequency of the VEMP. CAF showed a significant increase at the drive frequency of 7 and 15Hz compared with conventional artificial heart driving at the rate of 120 b. p. m. These results suggest that each frequency component of blood flow affects the peripheral blood flow distribution in the condition of hypoperfusion.

  367. Estimation of natural heart flow during left ventricular assistance based on time series analysis.

    MIURA M, SATO N, MOHRI H, YAMBE T, NITTA S, KOBAYASHI H, TAKEDA H, YOSHIZAWA M.

    Journal of the Japanese Society for Artificial Organs and Tissues 21 (2) 472-476 1992

    Publisher: JAPANESE SOCIETY FOR ARTIFICIAL ORGANS

    DOI: 10.11392/jsao1972.21.472  

    ISSN:0300-0818

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    A continuous, real-time monitoring method for the cardiac output during assistance with left ventricular assist device (LVAD) was developed based on time series analysis. During ejection of LVAD, parametric model for arterial load was identified by least square algorithm. Natural heart flow was estimated in its ejection period with use of the identified model inversely assuming the estimated parameters to be invariable during the cardiac cycle. Classical windkessel model with some modification was used for the estimation. In animal experiments cardiac output were changed by abrupt loading and unloading with 500ml of blood. Natural heart flow were well estimated with the counter pulsation with the delay time of 50%. However, the waveforms showed oscillation compared with measured ones. It is concluded that stroke volume of natural heart and cardiac output could be predicted well by this method.

  368. Experimental study of the optimal drive condition of the total artificial heart from the viewpoint of the neurophysiological aspects.

    YAMBE T, NITTA S, KATAHIRA Y, SONOBE T, NAGANUMA S, MATSUZAWA H, AKIHO H, KAKINUMA Y, IZUTSU K, SUGAWARA S, TANAKA M, MIURA M, SATO N, MOHRI H, IZUMI K, TAKEDA H, YOSHIZAWA M.

    Journal of the Japanese Society for Artificial Organs and Tissues 21 (2) 489-495 1992

    Publisher: JAPANESE SOCIETY FOR ARTIFICIAL ORGANS

    DOI: 10.11392/jsao1972.21.489  

    ISSN:0300-0818

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    In order to determine the optimal drive condition of total artificial heart, renal sympathetic nerve activity (RSNA) were analysed by the use of power spectrum and coherence function. Two pneumatically actuated sac type ventricular assist devices were implanted, and after the both pump driving, natural heart was electrically fibrillated to constitute the biventricular bypass (BVB) type TAH model. After the left frank was opened, bipolar electrode was attached to the left renal sympathetic nerve. Values of the squared coherence between the arterial pressure and RSNA were measured. Largest peak coherency was observed when BVB was driven at the same frequency of the natural heart beat before fibrillation, suggesting that that this frequency was the optimal for the baroreflex system.

  369. An automatic monitoring and estimation system for cardiovascular dynamics under ventricular assist device pumping and its controller.

    YOSHIZAWA M., KURAMOTO K., KOBAYASHI H., TAKEDA H., MMRA M., YAMBE T., KATAHIRA Y., NITTA S.

    Journal of the Japanese Society for Artificial Organs and Tissues 21 (3) 1251-1259 1992

    Publisher: JAPANESE SOCIETY FOR ARTIFICIAL ORGANS

    DOI: 10.11392/jsao1972.21.1251  

    ISSN:0300-0818

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    An automatic, on-line and real-time monitoring and estimation system (TOTOMES) for the cardiovascular dynamics under left ventricular assist device (LVAD) pumping has been developed to unload the operator who has to pay constant attention to the LVAD operation. The TOTOMES has the function which detects the presence and origin of accidents happening in the cardiovascular system, the pneumatic drive unit as well as the automatic controller. The parameters of the cardiovascular dynamics such as peripheral vessel resistance and arterial compliance are identified by using a time series model. The cardiac output of the natural heart is also estimated on the basis of the identified parameters. The inlet and outlet cannula resistances are calculated beat by beat on the basis of the principle of the optimal operating point. Detection of the malfunction is realized by using fuzzy logic. The combination of several measurements and estimates included in the antecedent of the fuzzy rules enables us to distinguish the origin of the malfunction. In <i>in vivo</i> experiment using an adult goat, it was ascertained that the proposed system successfully worked when the inlet cannula resistance was suddenly changed by clamping and when the blood withdrawing was carried out.

  370. Cardiac-related sympathetic nerve activity during circulation with only the left ventricular assist device. Peer-reviewed

    Yambe T, Nitta S, Katahira Y, Sonobe T, Naganuma S, Akiho H, Chiba S, Kakinuma Y, Hayashi H, Izutsu K

    Int J Artif Organs 15 (1) 49-54 1992/01

  371. Fundamental rhythm of sympathetic nerve discharges in animals with total artificial hearts Peer-reviewed

    T. Yambe, S. I. Nitta, Y. Katahira, T. Sonobe, S. Naganuma, Y. Kakinuma, H. Matsuzawa, M. Tanaka, M. Miura, N. Sato, H. Mohri, M. Yoshizawa, H. Takeda

    ASAIO Journal 38 (2) 91-95 1992

    ISSN:1058-2916

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    To evaluate the effect of total artificial heart replacement on the autonomic nervous system, sympathetic neurograms were analyzed by power spectrum and coherence function. Two pneumatically driven, sac type ventricular assist devices were implanted as biventricular bypasses (BVB) in adult, mongrel dogs. After initiation of BVB pumping, the natural heart was electrically fibrillated to form a BVB TAH model. Renal sympathetic nerve activity (RSNA) was recorded using a bipolar electrode attached to the left renal sympathetic nerve. RSNA was amplified and integrated by use of an R-C integrator. Power spectra of the RSNA and values of squared coherence between the arterial pressure wave form and the RSNA were calculated by computer. In animals with total artificial hearts (TAHs), coherence at the cardiac rhythm frequency was decreased, and coherence at the TAH pumping rhythm frequency was increased. These results indicate that the arterial pulse wave observed in TAH animals contributed to the sympathetic neurogram.

  372. Long-time inflation of the PTCA balloon. Peer-reviewed

    Yambe T, Nitta S, Chiba S, Saijoh Y, Naganuma S, Kakinuma Y, Tanaka M, Meguro T, Endoh N, Mitsuoka M

    Sci Rep Res Inst Tohoku Univ [Med] 38 (2月4日) 75-81 1991/12

  373. Systemic circulation with high frequency blood flow--analysis from neurophysiological point of view. Peer-reviewed

    Yambe T, Nitta S, Katahira Y, Sonobe T, Naganuma S, Kakinuma Y, Akiho H, Tanaka M, Fukuju T, Miura M

    Sci Rep Res Inst Tohoku Univ [Med] 38 (2月4日) 69-73 1991/12

  374. Echo-guided transaortic left ventricular myotomy for idiopathic hypertrophic subaortic stenosis. Peer-reviewed

    Nitta S, Yambe T, Nitta K, Katahira Y, Saijo Y, Sonobe T, Naganuma S, Kakinuma Y, Tanaka M, Miura M

    Sci Rep Res Inst Tohoku Univ [Med] 38 (2月4日) 65-67 1991/12

  375. Development and clinical evaluation of the long time digital Holter ECG system using non-tracking technology. Peer-reviewed

    Nitta S, Yambe T, Katahira Y, Sonobe T, Naganuma S, Chiba S, Kakinuma Y, Tanaka M, Miura M, Sato N

    Sci Rep Res Inst Tohoku Univ [Med] 38 (2月4日) 63-64 1991/12

  376. Hydrodynamic endurance test of the prosthetic valve used in the various types of the ventricular assist device. Peer-reviewed

    Nitta S, Yambe T, Katahira Y, Sonobe T, Saijoh Y, Naganuma S, Akiho H, Kakinuma Y, Tanaka M, Miura M

    Sci Rep Res Inst Tohoku Univ [Med] 38 (2月4日) 57-62 1991/12

  377. Sympathetic nerve activity during maintaining circulation with only left ventricular assist device. Peer-reviewed

    Nitta S, Yambe T, Katahira Y, Sonobe T, Naganuma S, Kakinuma Y, Tanaka M, Miura M, Sato N, Mohri H

    Sci Rep Res Inst Tohoku Univ [Med] 38 (2月4日) 51-56 1991/12

  378. The newly designed univalved artificial heart. Peer-reviewed

    Nitta S, Hashimoto H, Sonobe T, Katahira Y, Yambe T, Naganuma S, Tanaka M, Sato N, Miura M, Mohri H

    ASAIO Trans 37 (3) M240-1 1991/07

  379. Clinical application of the ventricular assist devices in Japan. Peer-reviewed

    Nitta S, Yambe T, Katahira Y, Sonobe T, Naganuma S, Akiho H, Kakinuma Y, Tanaka M, Miura M, Sato N

    Sci Rep Res Inst Tohoku Univ [Med] 38 (1) 5-10 1991/07

  380. Coherence function between sympathetic neurogram and arterial pulse wave in animal with total artificial heart. Peer-reviewed

    Yambe T, Nitta S, Katahira Y, Sonobe T, Naganuma S, Kakinuma Y, Akiho H, Matsuzawa H, Izutsu K, Kikuchi Y

    Sci Rep Res Inst Tohoku Univ [Med] 38 (1) 35-41 1991/07

  381. Development of the total artificial heart control system. Peer-reviewed

    Yambe T, Nitta S, Katahira Y, Sonobe T, Naganuma S, Akiho H, Kakinuma Y, Matsuzawa H, Izutsu K, Kikuchi Y

    Sci Rep Res Inst Tohoku Univ [Med] 38 (1) 29-34 1991/07

  382. TH-7B pneumatically driven sac-type ventricular assist device and drive system. Peer-reviewed

    Nitta S, Yambe T, Katahira Y, Sonobe T, Naganuma S, Akiho H, Chiba S, Kakinuma Y, Matsuzawa H, Hayashi H

    Sci Rep Res Inst Tohoku Univ [Med] 38 (1) 19-27 1991/07

  383. Development and evaluation of the vibrating electromagnetically-driven artificial heart. Peer-reviewed

    Nitta S, Yambe T, Katahira Y, Sonobe T, Naganuma S, Akiho H, Kakinuma Y, Tanaka M, Miura M, Sato N

    Sci Rep Res Inst Tohoku Univ [Med] 38 (1) 11-17 1991/07

  384. Spectral analysis of the renal sympathetic neurogram during left ventricular assistance. Peer-reviewed

    Nitta S, Yambe T, Katahira Y, Sonobe T, Naganuma S, Matsuzawa H, Akiho H, Hayashi H, Tanaka M, Miura M

    Sci Rep Res Inst Tohoku Univ [Med] 38 (1) 1-4 1991/07

  385. POSTGANGLIONIC SYMPATHETIC-NERVE ACTIVITY WITH CORRELATION TO HEART RHYTHM DURING LEFT-VENTRICULAR ASSISTANCE Peer-reviewed

    T YAMBE, S NITTA, Y KATAHIRA, T SONOBE, S NAGANUMA, H AKIHO, S CHIBA, Y KAKINUMA, H HAYASHI, M TANAKA, M MIURA, N SATOH, H MOHRI, M YOSHIZAWA, H TAKEDA

    ARTIFICIAL ORGANS 15 (3) 212-217 1991/06

    Publisher: BLACKWELL SCIENCE INC

    ISSN:0160-564X

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    In order to evaluate the effect of ventricular assist device (VAD) driving on the autonomic nervous system, sympathetic neurograms during left ventricular (LV) assistance were analyzed by power spectrum and coherence function. Our TH-7B pneumatically-driven sac-type VAD was used in seven adult mongrel dogs. VADs were inserted between the left atrium and the descending aorta. Renal sympathetic nerve activity (RSNA) was detected by use of bipolar electrodes attached to the left renal sympathetic nerve via a retroperitoneal approach. Values of squared coherence between the arterial pulse wave and RSNA were measured at the same frequency of cardiac and VAD pumping rhythms. During LV assistance, coherence at the cardiac rhythm frequency was decreased, and coherence at the VAD pumping rhythm frequency was increased. These results indicate that the arterial pulse wave, which was produced by the VAD assistance, contributed to postganglionic sympathetic nerve activity.

  386. [A case of giant cell myocarditis associated with a progressive disturbance in the conduction system] Peer-reviewed

    Saijo Y, Nitta S, Katahira Y, Takahashi K, Yambe T, Endoh N, Sonobe T, Tanaka M, Meguro T, Nitta K

    Kokyu To Junkan 39 (4) 373-376 1991/04

    DOI: 10.11477/mf.1404900261  

  387. Silent obstruction of the coronary stenosis between diagnostic angiography and later percutaneous transluminal coronary angioplasty without myocardial infarction. Peer-reviewed

    Yambe T, Nitta S, Chiba S, Saijoh Y, Naganuma S, Akiho H, Kakinuma Y, Izutsu K, Kikuchi Y, Naganuma T

    Tohoku J Exp Med 163 (3) 167-174 1991/03

    DOI: 10.1620/tjem.163.167  

  388. Estimation and monitoring system of the cardiovascular dynamics under ventricular assist device pumping based on a time series model.

    YOSHIZAWA M, KURAMOTO K, TAKEDA H, MIURA W, YAMBE T, KATAHIRA Y, NITTA S

    Journal of the Japanese Society for Artificial Organs and Tissues 20 (3) 848-857 1991

    Publisher: JAPANESE SOCIETY FOR ARTIFICIAL ORGANS

    DOI: 10.11392/jsao1972.20.848  

    ISSN:0300-0818

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    The estimation and monitoring system of the cardiovascular dynamics under ventricular assist device (LVAD) pumping has been developed on the basis of a time series model. This system has the functions which can identify the parameters of the cardiovascular dynamics such as peripheral vessel resistance and arterial compliance beat by beat and can estimate the instantaneous value of the cardiac output of the natural heart assisted by the LVAD. The required measurements are only the aortic pressure and the outflow rate from the LVAD measured with an electromagnetic flow meter outside the body. In this system, the parameter identification of the cardiovascular dynamics and the estimation of the flow rate wave form of the cardiac output can be realized in an on-line and real time fashion. Hence, the proposed system is useful for monitoring the hemodynamic behavior of the circulatory system supported by the LVAD and for developing an automatic control system in which the driving conditions are automatically changed on the basis of the estimated cardiac output.

  389. Experimental study of cardiac-related sympathetic nerve activity during left ventricular assistance.

    YAMBE T, NITTA S, KATAHIRA Y, SONOBE T, NAGANUMA S, AKIHO H, TANAKA M, MIURA M, SATO N, MOHRI H, YOSIZAWA M, TAKEDA H

    Journal of the Japanese Society for Artificial Organs and Tissues 20 (3) 893-898 1991

    Publisher: JAPANESE SOCIETY FOR ARTIFICIAL ORGANS

    DOI: 10.11392/jsao1972.20.893  

    ISSN:0300-0818

    More details Close

    In order to determine the effect of left ventricular assistance on cardiac related sympathetic activity, renal sympathetic nerve activity (RSNA) were analysed by the use of power spectrum and coherence function. Our TH-7H pneumatically driven sac type ventricular assist device ( VAD ) was used in 7 adult mongrel dogs. VADS were inserted between the left atrium and the descending aorta. After the left frank was opened, bipolar electrode was attached to the left renal sympathetic nerve via retroperitoneal approach to detect the RSNA. Values of the squared coherence between the arterial pressure waveform and RSNA were measured at the same frequency level of cardiac rhythm and VAD pumping rhythm. With the LVAD pumping, coherence spectra at the cardiac rhythm frequency was decreased, and the coherence at the pumping rhythm frequency was increased. These results indicate that arterial pulse wave which was made by the LVAD assistance contributed to the postganglionic sympathetic activity.

  390. Evaluation of a pressure sensor in cannula for ventricular assist device.

    HAYASHI H., NITTA S., KATAHIRA Y., YAMBE T., SONOBE T., NAGANUMA S., AKIHO H., TANAKA M., HONGOH T., SATOH N., MIURA M., MOHRI H., NAGASE T.

    Journal of the Japanese Society for Artificial Organs and Tissues 20 (3) 693-698 1991

    Publisher: JAPANESE SOCIETY FOR ARTIFICIAL ORGANS

    DOI: 10.11392/jsao1972.20.693  

    ISSN:0300-0818

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    Characteristics of a pressure microsensor for automatic control of ventricular assist device (VAD) have been evaluated. The sensor consists of a Pyrex glass cover and a silicon chip. This absolute pressure sensor has high stability because of the four resistors diffused into the diaphragm. The sensor is built in outflow cannula which is sustained with thin membrane of anti-thrombogenic material together with surface of cannula. After 60 days VAD drive in the moo circulatory loop, satisfactory stability and performance were shown. This result indicates the possibility of the clinical application of this pressure sensor in cannula for VAD.

  391. A power spectral analysis of heart rate variability for the automatic control system of ventricular assist device.

    KATAHIRA Y, NITTA S, YAMBE T, SONOBE T, NAGANUMA S, AKIHO H, HAYASHI H, TANAKA M, SATOH N, MIURA M, MOHRI H, IZUMI K, YOSHIZAWA M, TAKEDA H

    Journal of the Japanese Society for Artificial Organs and Tissues 20 (3) 858-864 1991

    Publisher: JAPANESE SOCIETY FOR ARTIFICIAL ORGANS

    DOI: 10.11392/jsao1972.20.858  

    ISSN:0300-0818

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    In order to evaluate the autonomic response of conscious adult goats under the systemic ventricular assistance, the power spectrum of the heart rate variability was analyzed using the newly developed system. The power spectra were analyzed on the several different conditions; (1) asynchronous mode of different assist volumes and different driving frequencies, (2) synchronous mode of the constant assist volume and different time-delays from R-wave. In the asynchronous mode, the low-peak (Mayer wave) and the high-peak (respiratory arrhythmia) were clearly observed. On the contrary, in the synchronous mode with time-delays of 300, 400 and 500 ms, the low-peak was attenuated. Because this autonomic response under the synchronous assistance is different from that produced by administration of the β-blockade which attenuates the sympathetic activity, the synchronous assistance may influence the response of the sympathetic nervous system to physiological disturbances. In addition, power spectra were processed by means of the maximum entropy method for the automatic control system. Using this method, both the locations and the strengths of spectral peaks could be automatically calculated. It was concluded that the power spectral analysis of the heart rate could be useful as one of the information for the automatic control system of ventricular assist device.

  392. Experimental study of external work and pressure-volume area of left ventricle from pressure-volume curve in left ventricular assistance.

    AKIHO H, NITTA S, KATAHIRA Y, YAMBE T, SONOBE T, NAGANUM S, TANAKA M, MIURA M, SATOH N, MOHRI H, YOSHIZAWA M, TAKEDA H

    Journal of the Japanese Society for Artificial Organs and Tissues 20 (3) 835-840 1991

    Publisher: JAPANESE SOCIETY FOR ARTIFICIAL ORGANS

    DOI: 10.11392/jsao1972.20.835  

    ISSN:0300-0818

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    In order to evaluate cardiac function of natural heart during left ventricular assistance, external work and pressure-volume area (PVA), which were calculated from left ventricular pressure-volume curve, were analysed by our hemodynamics analysing system and automatic control system. Our TH-7B pneumatically driven sac type Ventricular Assist device (VAD) was used in 6 adult goats in acute animal experiments. VAD were inserted between the left atrium and the descending aorta. Coductance catheter and catheter tip manometer were inserted into the left ventricle. External work decreased and PVA increased in co-pulsation mode (CoP) compared with counterpulsation mode (CP). External work calculated by our system changed in proportion to the positive and negative inotropic agents. These results indicate that cardiac function of natural heart under left ventricular assistance can be obtained with this newly developed system.

  393. Hemodynamic change during the left herat bypass using vibrating electro-magnetic pump.

    SONOBE T, NITTA S, KATAHIRA Y, YAMBE T, NAGANUMA S, AKIHO H, HAYASHI H, MIURA M, SATOH N, MOHRI H, HIYAMA H, HASHIMOTO H, TANAKA M

    Journal of the Japanese Society for Artificial Organs and Tissues 20 (3) 670-675 1991

    Publisher: JAPANESE SOCIETY FOR ARTIFICIAL ORGANS

    DOI: 10.11392/jsao1972.20.670  

    ISSN:0300-0818

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    In order to develop a new totally implantable artificial herat using vibrating electroagnetic pump (VEMP) which generates flow with the frequency of 1-30 Hz, effects of VEMP drive on hemodynamic parameters were examined. Hemodynamic properties during VEMP drive were evaluated in the frequencys of 5, 10 and 20 Hz using adult goats in 10 acute experiments. This pump acted very well as a left ventricular assist device in any kinds of frequency in the satisfied physiological condition. These results suggest that the VEMP is useful for a totally implantable assist device or a total artificial heart.

  394. Experimental study of sympathetic nerve activity in animal with total artificial heart.

    YAMBE T, NITTA S, KATAHIRA Y, SONOBE T, NAGANUMA S, AKIHO H, KAKINUMA Y, IZUTSU K, SUGAWARA S, TANAKA M, MIURA M, SATO N, MOHRI H, YOSHIZAWA M, IZUMI K, TAKEDA H

    Journal of the Japanese Society for Artificial Organs and Tissues 20 (5) 1434-1439 1991

    Publisher: JAPANESE SOCIETY FOR ARTIFICIAL ORGANS

    DOI: 10.11392/jsao1972.20.1434  

    ISSN:0300-0818

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    In order to determine the effect of total artificial heart on autonomic nervous system, renal sympathetic nerve activity (RSNA) were analysed by the use of power spectrum and coherence function. Two pneumatically actuated sac type ventricular assist devices were implanted as biventricular bypass (BVB) in animal experiments. After the BVB pumping, natural heart was electrically fibrillated to constitute a BVB type of TAH model. After the left frank was opened bipolar electrode was attached to the left renal sympathetic nerve via retroperitoneal approach to detect the RSNA. Values of the squared coherence between the arterial pressure waveform and RSNA were measured at the same frequency level of cardiac rhythm and VAD pumping rhythm. With the TAH pumping, coherence spectra at the cardiac rhythm frequency was decreased, and the coherence at the pumping rhythm frequency was increased. These results indicate that arterial pulse wave which was made by TAR contributed to the postganglionic sympathetic activity.

  395. Micro-pressure sensor for continuous monitoring of a ventricular assist device. Peer-reviewed

    Nitta S, Katahira Y, Yambe T, Sonobe T, Hayashi H, Tanaka M, Sato N, Miura M, Mohri H, Esashi M

    Int J Artif Organs 13 (12) 823-829 1990/12

  396. Experimental study of renal sympathetic nerve activity during left ventricular assist device pumping. Peer-reviewed

    Yambe T

    Sci Rep Res Inst Tohoku Univ [Med] 37 (1月4日) 1-9 1990/12

  397. Effect of left ventricular assistance on sympathetic tone. Peer-reviewed

    Yambe T, Nitta S, Katahira Y, Sonobe T, Tanaka M, Miura M, Satoh N, Mohri H, Yoshizawa M, Takeda H

    Int J Artif Organs 13 (10) 681-686 1990/10

  398. [A case of aortitis syndrome] Peer-reviewed

    Ito H, Shimanuki Y, Endoh N, Takeda H, Yambe T, Matsumoto K, Sakamoto K

    Rinsho Hoshasen 35 (9) 1065-1068 1990/09

  399. 交感神経活動と血行動態の重回帰分析による左心補助人工心臓(LVAD)駆動目標値設定に関する実験的研究 Peer-reviewed

    山家智之, 仁田新一, 片平美明

    人工臓器 19 (1) 133-138 1990/02

    Publisher: JAPANESE SOCIETY FOR ARTIFICIAL ORGANS

    DOI: 10.11392/jsao1972.19.133  

    ISSN:0300-0818

    More details Close

    In order to develop the real time automatic control system of the ventricular assist device, we use the multiple regression analysis of the sympathetic tone and hemodynamic data. Mean left atrial pressure and mean aortic pressure were used as the parameters of the preload and afterload, and Renal Sympathetic Nerve Activity was also utilized to evaluate the sympathetic tone. A functional formula of the prospective cardiac output was calculated by the time series data of the acute animal experiments using adult mongrel dogs. A significant correlation was observed between the prospective cardiac output and the measured cardiac output.This result suggests the possibility of the prospective control of the artificial heart.

  400. 臨床用補助人工心臓(VAD)のための人工弁の流れの可視化法による評価 傾斜型ディスク弁とボール弁の比較 Peer-reviewed

    片平美明, 仁田新一, 山家智之

    人工臓器 19 (1) 319-322 1990/02

    Publisher: JAPANESE SOCIETY FOR ARTIFICIAL ORGANS

    DOI: 10.11392/jsao1972.19.319  

    ISSN:0300-0818

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    It is very important to grasp the fluid-mechanical property of a prosthetic valve on the various driving conditions, in order to develop a ventricular assist device (VAD). Therefore, the flow characteristics of a newly designed ball valve which consisted of a silicone ball and a polycarbonate housing was analized by means of the quantitative flow visualization technique and was compared with the Björk-Shiley prosthetic valve (BS-19ABP, spherical). The flow visualizations were carried out on the four different flow rate conditions (3.0, 2.0, 1.5 and 1.0L/min). It was observed that the decrease of flow rate effected neither on the maximum velocity nor on the velocity vector distributions of a ball valve in comparison with the Björk-Shiley valve. Furthermore, even on the low flow rate condition(1.0L/min), the decreases of the flow velocity and the shear rate, which could cause the thrombus formation, were not observed in the lower part of a ball valve. In conclusion, a newly designed ball valve has the fluid-mechanical property which meets the requirement of VAD.

  401. Evaluation of left ventricular function during the assistance with the pneumatic ventricular assist device.

    MIURA M., SATO N., MOHRI H., SONOBE T., YAMBE T., KATAHIRA Y., NITTA S., YOSHIZAWA M.

    Journal of the Japanese Society for Artificial Organs and Tissues 19 (1) 147-150 1990

    Publisher: JAPANESE SOCIETY FOR ARTIFICIAL ORGANS

    DOI: 10.11392/jsao1972.19.147  

    ISSN:0300-0818

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    In this study, the left ventricle and artery were modelled on timevaring elastance and windkessel model respectively. In copulsation mode of left ventricle and left ventricular assist device (LVAD), the sum of the arterial capacitance and the reciprocal of left ventricular elastance which is equivalent to capacitance can be estimated by the time-series analysis of the pneumatic drive pressure and blood output from LVAD, based on the on-line identification method of adaptive control of the pneumatic driver. In animal experiments, it was shown that reciprocal value of the estimated capacitance were correlated with actual Emax, provided that heart rate was stable and less than 120/min.

  402. Development and evaluation of pressure micro sensors in cannulae for ventricular assist device.

    HAYASHI H., NITTA S., KATAHIRA Y., YAMBE T., SONOBE T., NAGANUMA S., AKIHO Y., TANAKA M., HONGOH T., SATOH N., MIURA M., MOHRI H., NAGASE T.

    Journal of the Japanese Society for Artificial Organs and Tissues 19 (1) 21-24 1990

    Publisher: JAPANESE SOCIETY FOR ARTIFICIAL ORGANS

    DOI: 10.11392/jsao1972.19.21  

    ISSN:0300-0818

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    A pressure micro sensor for automatic control of ventricular assist device (VAD) has been developed and evaluated. The sensor is built in both inflow and outflow cannulae which are sustained with a stainless steel pipe to prevent other hazardous foreign force and coated with thin membrane of anti-thrombogenic material together with surface of both cannulae. After 20 days drive in the mock circulation, sensor showed less temperature drift and good sensitivity which suggest the usefulness and the readiness for the clinical application of automatic control system.

  403. The development and evaluation of vibrating electro-magnetic pump for the artificial heart.

    SONOBE T., NITTA S., KATAHIRA Y., YAMBE T., NAGANUMA S., AKIHO H., HAYASHI H., MIURA M., SATOH N., MOHRI H., HIYAMA H., HASHIMOTO H., TANAKA M.

    Journal of the Japanese Society for Artificial Organs and Tissues 19 (1) 113-116 1990

    Publisher: JAPANESE SOCIETY FOR ARTIFICIAL ORGANS

    DOI: 10.11392/jsao1972.19.113  

    ISSN:0300-0818

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    In order to miniaturize an artificial herat, we have been developing a Vibrating Electro-Magnetic Pump(VEMP) which has an unique structure and fluid mechanism. The fluid mechanical characteristics of the VEMP were analyzed by using mock circulatory loop. The fundamental vibration, which was modulated with the vibration of the another frequency, could generated the particular complex pressure and flow patterns. It was observed that the VEMP could ejected the sufficient flow volume against the systemic pressure in acute animal experiments. The values of free Hb after the in vitro and in vivo experiments were remained within the satisfactory limits of value. In conclusion the VEMP could be available to the clinical use for the artificial heart in spite of the necessity of further improvement.

  404. 人工弁の流れの可視化法による流体力学的解析 とくに低流量駆動補助人工心臓下での流れについて Peer-reviewed

    片平美明, 仁田新一, 山家智之

    人工臓器 18 (2) 633-636 1989/04

    Publisher: JAPANESE SOCIETY FOR ARTIFICIAL ORGANS

    DOI: 10.11392/jsao1972.18.633  

    ISSN:0300-0818

    More details Close

    It is very important to grasp the flow characteristics of a prosthetic valve on the various driving conditions in order to develop a VAD. Therefore, the fluidmechanical property of Björk-Shiley prosthetic valve (BS-21ABP, spherical) was analized by means of the quantitative flow visualization technique. The flow visualizations were carried out on the four different flow rate conditions (3.0, 2.0, 1.5 and 1.0 1/min). It was observed that the decrease of flow rate effected not on the maximum velocity but on the velocity vector distributions. On the low flow rate condition (1.0 1/min), the decreases of the flow velocity and the shear rate, which could cause the thrombus formation, were observed in a minor-orifice and its lower part. In conclusion, it is necessary to keep the VAD flow rate more than 1.5 1/min to prevent the thrombus formation on the prosthetic valve.

  405. 腎交感神経情報を用いた補助人工心臓至適駆動条件設定に関する実験的研究 Peer-reviewed

    山家智之, 仁田新一, 片平美明

    人工臓器 18 (2) 584-587 1989/04

    Publisher: JAPANESE SOCIETY FOR ARTIFICIAL ORGANS

    DOI: 10.11392/jsao1972.18.584  

    ISSN:0300-0818

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    To assess effects of LVAD pumping on renal circulatory condition, RSNA and hemodynamic parameters were detected in 7 acute animal experiments. RSNA was significantly inhibited in its frequency and amplitude with both co-pulsation (COP) and counter pulsation (CP) modes compared to off-LVAD especially in CP mode. It is concluded that RSNA measurement is very useful to evaluate the renal circulation in the sence of vascular impedance which affects to cause multiple organ failure (MOF) by increasing arterial impedance.

  406. 急性心筋梗塞に対するPTCAの検討 Invited Peer-reviewed

    山家智之

    Japanese Circulation Journal 53 (Suppl.1) 28-28 1989/04

  407. 腎交感神経活動電位によるペースメーカ制御に関する実験的研究

    山家智之

    心臓ペーシング 5 (2) 197-197 1989/03

  408. 悪性腎血管性高血圧に対するACE阻害剤の2剤併用について Peer-reviewed

    山家智之, 武田久尚, 海野金次郎

    Progress in Medicine 9 (3) 1170-1173 1989/03

  409. PTCAの適応拡大 積極的リハビリテーション後の運動負荷心筋スキャンを用いての検討 Peer-reviewed

    山家智之

    日本内科学会雑誌 78 (2) 299-299 1989/02

  410. リハビリテーションによる陳旧性心筋梗塞領域への冠動脈側副血行路の改善 運動負荷心筋シンチグラフィーによる検討 Peer-reviewed

    山家智之, 松本直晃, 武田久尚

    カレントテラピー 7 (1) 143-148 1989/01

  411. Expanded indication of percutaneous transluminal coronary angioplasty to the infarcted zone - Using thallium-201 exercise scintigram after rehabilitation Peer-reviewed

    T. Yambe, H. Takeda, K. Unno, Y. Murata, Y. Shimanuki, H. Itoh, N. Matsumoto, S. Yoshida, T. Konnai, M. Tadokoro, T. I. Meguro, S. I. Nitta, M. Tanaka

    Kakuigaku 26 (6) 781-786 1989

    ISSN:0022-7854

    More details Close

    In some cases of old myocardial infarction (OMI), left ventricular wall motion was improved after revascularization, though viability of the infarcted myocardium was not detected by left ventriculography (LVG) and exercise thallium-201 myocardial scintigraphy (EX-Tl). So to obtain more correct information of the viability, EX-Tl was performed again after ergometer rehabilitation for an OMI patient whose myocardial viability of the infarcted zone could not be detected by LVG and EX-Tl. Incomplete fill in was showed in the EX-Tl after rehabilitation. So percutaneous transluminal coronary angioplasty (PTCA) was performed. Left ventricular wall motion was improved after three months. EX-Tl after rehabilitation is useful to evaluate the viability that could not be detected by LVG and EX-Tl.

  412. リハビリテーションによるPTCAの適応拡大 運動負荷心筋シンチグラフィーによる検討 Invited Peer-reviewed

    山家智之

    抗酸菌病研究所雑誌 40 (3〜4) 324-324 1988/12

  413. 心房内浸潤を認めたMalignant Lymphomaの1症例

    山家智之

    Japanese Circulation Journal 52 (Suppl.1) 24-24 1988/09

  414. 補助人工心臓用コネクター内蔵型ボール弁の水力学的機能特性

    山家智之

    抗酸菌病研究所雑誌 40 (1) 65-65 1988/09

  415. 左心補助人工心臓駆動の腎交感神経活動に及ぼす影響についての実験的研究

    山家智之

    日本胸部外科学会雑誌 36 (臨増) 1950-1950 1988/08

  416. 流れの可視化とその解析により改良されたサック型補助人工心臓のin vivo評価 Peer-reviewed

    片平美明, 仁田新一, 山家智之

    人工臓器 17 (3) 863-866 1988/06

    Publisher: JAPANESE SOCIETY FOR ARTIFICIAL ORGANS

    DOI: 10.11392/jsao1972.17.863  

    ISSN:0300-0818

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    The flow behavior within our different several types of ventricular assist devices (VADs) had been analized with the numerical method based on the quantitative flow visualization technique. In order to evaluate the in vivo flow characteristics of VAD, the chronic animal experiments were carried out using 21 goats without administration of any anti-coagulant and anti-platelet therapy. In these experiments, 9 goats (43%) survived more than 30 days and the average survival period was 26.5 days. The thrombi within VADs were observed in 5 cases (24%). According to the results of flow characteristics within VADs analized with the quantitative flow visualization technique, the contour of the junctions between the sack and the inflow and outflow tracts were improved to the smooth configuration which enhanced the rotating flow in the diastole and minimized the stagnant area within the sack. The thrombus generation of the improved VAD was significantly reduced from 67% to 7% in rate and extremely minimized in size. We concluded that these results showed the clinical readiness of our VADs.

  417. 東北大学型補助人工心臓用コネクター内蔵型人工弁の水力学的機能特性 Peer-reviewed

    山家智之

    抗酸菌病研究所雑誌 39 (3〜4) 440-441 1987/12

  418. 補助人工心臓自動制御時の循環動態の対応 Peer-reviewed

    仁田新一, 片平美明, 山家智之

    電子情報通信学会技術研究報告(MEとバイオサイバネティックス) 87 (204) 1-6 1987/10

  419. 臨床用補助人工心臓の開発と評価

    山家智之

    抗酸菌病研究所雑誌 39 (2) 361-361 1987/10

  420. Preclinical evaluation of a improved and modified ventricular assist device and a driving system.

    NITTA S., KAGAWA Y., HONGO T., SATO N., KATAHIRA Y., MIURA M., AKINO Y., YAMBE T., NISHI K., TSUJI T., YODA R., TANAKA M., HORIUCHI T.

    Journal of the Japanese Society for Artificial Organs and Tissues 16 (1) 203-206 1987

    Publisher: JAPANESE SOCIETY FOR ARTIFICIAL ORGANS

    DOI: 10.11392/jsao1972.16.203  

    ISSN:0300-0818

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    We have been involved in the preclinical design, development and animal testing of ventricular assist device (VAD) and its driving system. This prematically driven pump is situated out side of the chest, has two types of maximum stroke volume of 53 and 43m/s and is capable of automatic control with a host computer system through the interface of a driving system. Micro sensors in VAD outflow and inflow cannulae of atrial and arterial pressures, pH and pC02 of blood are used as a input data for an automatic control system.

  421. 臨床用補助人工心臓の流れの可視化法による検討 Peer-reviewed

    片平美明, 仁田新一, 山家智之

    外科治療 55 (5) 796-797 1986/11

  422. 補助人工心臓の自動制御 Peer-reviewed

    三浦誠, 山家智之, 片平美明

    電子通信学会技術研究報告(MEとバイオサイバネティックス) 86 (179) 39-43 1986/10

  423. 人工心臓自動制御用生体情報計測法の開発と評価 Peer-reviewed

    仁田新一, 片平美明, 山家智之

    電子通信学会技術研究報告(MEとバイオサイバネティックス) 86 (179) 31-38 1986/10

  424. 人工心臓内の流れの可視化

    山家智之

    医用電子と生体工学 24 (2) 138-138 1986/04

  425. 補助人工心臓自動制御システムの開発 各種マイクロセンサのin vitro評価 Peer-reviewed

    仁田新一, 片平美明, 山家智之

    人工臓器 15 (2) 646-649 1986/04

    Publisher: JAPANESE SOCIETY FOR ARTIFICIAL ORGANS

    DOI: 10.11392/jsao1972.15.646  

    ISSN:0300-0818

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    Piezorsistive pressure sensors and ISFET micro sensors (pH, Pco<sub>2</sub>) for the use of the information from circulatory condition during a left ventricular assist device (LVAD) pumping have been developed and evaluated. These micro sensors were built in the inflow and outflow cannulae. Micro pressure sensors and ISFET sensors were coated with antithrombogenic materials such as cardiothane and hydrophilic polyurethane respectively. In the chronic animal study, enough sensitivity and reliability for an automatic control system of LVAD have been obtained.

  426. 流れの可視化法による人工心臓内の流れの解析 Peer-reviewed

    片平義明, 仁田新一, 山家智之

    人工臓器 15 (2) 478-481 1986/04

    Publisher: JAPANESE SOCIETY FOR ARTIFICIAL ORGANS

    DOI: 10.11392/jsao1972.15.478  

    ISSN:0300-0818

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    The flow behavior within an artificial heart (AR) in the various driving conditions were analyzed with a numerical method based on the quantitative flow visualization techniques. The velocity vector distribution, the streamline configuration and the vorticity distribution within the AH were obtained with this method. In this study, the flow velocity within the AR showed the parallel changes with the stroke volume, but showed the sudden decrease in the flow velocity and the sudden change in the distribution pattern beyond a certain driving condition. Since this critical point was thought to be a minimum stroke volume, the driving condition should be avoided in this area to protect AH from thrombus formation.

Show all ︎Show first 5

Misc. 185

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    下川柚依, 田中明, 吉澤誠, 白石泰之, 山家智之

    人工臓器(日本人工臓器学会) 51 (2) 2022

    ISSN:0300-0818

  2. 補助人工心臓の任意のポンプ特性を実現する拍内制御

    八巻大祐, 田中明, 吉澤誠, 白石泰之, 山家智之

    人工臓器(日本人工臓器学会) 51 (2) 2022

    ISSN:0300-0818

  3. 補助人工心臓のインペラの非対称性を利用した拡張期の逆流検出と拍動制御

    サワリナタンジョセリンアン, 田中明, 吉澤誠, 白石泰之, 山家智之

    人工臓器(日本人工臓器学会) 51 (2) 2022

    ISSN:0300-0818

  4. 連続流型補助人工心臓における拡張期の逆流検出と完全拍動制御

    サワリ ナタンジョセリンアン, 田中明, 吉澤誠, 白石泰之, 山家智之

    人工臓器(日本人工臓器学会) 50 (2) 2021

    ISSN:0300-0818

  5. 補助人工心臓運の拍動同期制御を利用した大動脈弁逆流の検出

    丹治洸太郎, 田中明, 吉澤誠, 白石泰之, 山家智之

    人工臓器(日本人工臓器学会) 50 (2) 2021

    ISSN:0300-0818

  6. Evaluation of the Effects of the Changes in Flow Channel Deformation by Cyclic Loading on Blood Flow Characteristics in a Roller Pump Model Peer-reviewed

    ライフサポート 33 (2) 52-58 2021

    Publisher: ライフサポート学会

    ISSN:1341-9455

  7. 非線形ARXモデルを用いた補助人工心臓装着時の循環系パラメータの逐次同定と大動脈弁動作の推定

    平木倫, 田中明, 吉澤誠, 白石泰之, 山家智之

    人工臓器(日本人工臓器学会) 49 (3) 2020

    ISSN:0300-0818

  8. 大動脈弁閉鎖不全時に補助人工心臓の制御様式が弁逆流に与える影響

    丹治洸太郎, 田中明, 吉澤誠, 白石泰之, 山家智之

    人工臓器(日本人工臓器学会) 49 (3) 2020

    ISSN:0300-0818

  9. 畳み込みニューラルネットワークを用いた左心補助人工心臓装着時の大動脈弁開閉動作の推定

    中谷修士, 田中明, 吉澤誠, 白石泰之, 山家智之

    人工臓器(日本人工臓器学会) 49 (3) 2020

    ISSN:0300-0818

  10. ステントグラフト治療後の反射波増加は大動脈径に依存する:ヤギ実験モデルにおけるwave intensityの評価

    高野智弘, 高野真澄, 高野真澄, 坪子侑佑, 坪子侑佑, 白石泰之, 山家智之, 横山斉

    脈管学(Web) 60 (supplement) 2020

    ISSN:1880-8840

  11. Possibilities and Limitations of Video Plethysmography as Wear ”less”-Monitoring

    吉澤誠, 杉田典大, 湯田恵美, 田中明, 本間経康, 山家智之

    日本生体医工学会大会プログラム・抄録集(Web) 59th 2020

  12. Possibilities and Limitations of Video Plethysmography as Wear“less”-Monitoring

    吉澤誠, 杉田典大, 湯田恵美, 田中明, 本間経康, 山家智之

    日本生体医工学会大会プログラム・抄録集(Web) 59th 2020

  13. 微細管路系による流体剪断負荷とvon Willebrand factor損傷に関する特性評価の基礎検討

    舘崎 祐馬, 白石 泰之, 井上 雄介, 山田 昭博, 岩元 直樹, 盛田 良介, Ibadurrahman Ahmad Faiz, 橋本 真登香, 堀内 久徳, 早川 正樹, 松本 雅則, 萱島 道徳, 山家 智之

    人工臓器 48 (2) S-241 2019/10

    Publisher: (一社)日本人工臓器学会

    ISSN:0300-0818

    eISSN:1883-6097

  14. 補助人工心臓装着時循環系の主要な循環パラメータの逐次同定と大動弁開閉動作の推定

    平木倫, 田中明, 吉澤誠, 白石泰之, 山家智之

    人工臓器(日本人工臓器学会) 48 (2) 2019

    ISSN:0300-0818

  15. 映像脈波を用いた血圧推定の可能性

    杉田典大, 吉澤誠, 野呂泰平, 八巻俊輔, 市地慶, 本間経康, 山家智之

    日本生体医工学会大会プログラム・抄録集(Web) 58th 2019

  16. 補助人工心臓治療の血液凝固関連における新知見 高せん断応力とフォンウィルブランド因子に関する基礎研究

    井上 雄介, 早川 正樹, 松本 雅則, 堀内 久徳, 山田 昭博, 白石 泰之, 軽部 雅人, 源田 達也, 岩元 直樹, 舘崎 祐馬, 盛田 良介, 山家 智之

    人工臓器 47 (2) S-30 2018/10

    Publisher: (一社)日本人工臓器学会

    ISSN:0300-0818

  17. 高ひずみ剪断流体のVWF損傷評価用往復動流体試験システムの開発

    舘崎 祐馬, 白石 泰之, 井上 雄介, 山田 昭博, 軽部 雅人, 源田 達也, 岩元 直樹, 盛田 良介, 堀内 久徳, 松本 雅則, 早川 正樹, 山家 智之

    人工臓器 47 (2) S-167 2018/10

    Publisher: (一社)日本人工臓器学会

    ISSN:0300-0818

  18. 補助人工心臓治療の血液凝固関連における新知見 高せん断応力とフォンウィルブランド因子に関する基礎研究

    井上 雄介, 早川 正樹, 松本 雅則, 堀内 久徳, 山田 昭博, 白石 泰之, 軽部 雅人, 源田 達也, 岩元 直樹, 舘崎 祐馬, 盛田 良介, 山家 智之

    人工臓器 47 (2) S-30 2018/10

    Publisher: (一社)日本人工臓器学会

    ISSN:0300-0818

  19. 高ひずみ剪断流体のVWF損傷評価用往復動流体試験システムの開発

    舘崎 祐馬, 白石 泰之, 井上 雄介, 山田 昭博, 軽部 雅人, 源田 達也, 岩元 直樹, 盛田 良介, 堀内 久徳, 松本 雅則, 早川 正樹, 山家 智之

    人工臓器 47 (2) S-167 2018/10

    Publisher: (一社)日本人工臓器学会

    ISSN:0300-0818

  20. ビデオカメラによる遠隔・非接触的血圧変動推定

    吉澤誠, 杉田典大, 阿部誠, 田中明, 本間経康, 山家智之

    日本生体医工学会大会プログラム・抄録集(Web) 56th 2017

  21. 映像脈波によるサイバー健康管理

    吉澤誠, 杉田典大, 阿部誠, 田中明, 本間経康, 山家智之

    日本生体医工学会大会プログラム・抄録集(Web) 56th 2017

  22. 3次元深度画像情報を用いた非接触の嚥下挙動解析の試み

    平恭紀, 白石泰之, 山田昭博, 坪子侑佑, 井上雄介, 荒川友哉, 弓場充, 山家智之

    日本生体医工学会大会プログラム・抄録集(Web) 56th 2017

  23. Estimation of autonomic nervous activity using green light photoplethysmogram

    116 (227) 29-34 2016/09/24

    Publisher: 電子情報通信学会

    ISSN:0913-5685

  24. 医療用ハイブリッド材料の滅菌に関する研究

    井上雄介, 田代彩夏, 磯山隆, 斎藤逸郎, 阿部裕輔, 白石泰之, 山田昭博, 坪子侑佑, 原伸太郎, 圦本晃海, 三浦英和, 山家智之

    LIFE講演概要集(CD-ROM) 2016 ROMBUNNO.1P2‐F04-069 2016/09/04

    Publisher: (一社)ライフサポート学会

  25. 低レイノルズ数領域における血液環流フローチャンバーシステムの開発

    安西眸, 白石泰之, 山家智之, 太田信

    日本バイオレオロジー学会誌(Web) 30 (2) 2016

    ISSN:2186-5663

  26. Newly development of implantable Fontan circulation assist device

    Yamada Akihiro, Yambe Tomoyuki, Shiraishi Yasuyuki, Miura Hidekazu, Taira Yasunori, Tsuboko Yusuke, Ikeda Jyunpei, Inoue Yusuke, Yamagishi Masaaki, Homma Dai

    Transactions of Japanese Society for Medical and Biological Engineering 54 (26) S52-S52 2016

    Publisher: Japanese Society for Medical and Biological Engineering

    DOI: 10.11239/jsmbe.54Annual.S52  

    ISSN:1347-443X

  27. 生体適合性の高い補助人工心臓用ハイブリッド脱血カニューレの開発

    井上雄介, 井上雄介, 川瀬由季乃, 田代彩夏, 磯山隆, 斎藤逸郎, 小野俊哉, 原伸太郎, 圦本晃海, 李欣陽, 村上遥, 前野映里奈, 三浦英和, 白石泰之, 山家智之, 井街宏, 阿部裕輔

    人工臓器(日本人工臓器学会) 44 (2) S.84-84 2015/10/30

    Publisher: (一社)日本人工臓器学会

    ISSN:0300-0818

  28. PS1-4 Evaluation of frozen vascular grafts by using MRE : how to keep the characteristics of bioprostheses?(PS1: Poster Short Presentation I,Poster Session)

    Watanabe Shota, Taira Yasunori, Suzuki Hayato, Miura Hidekazu, Inoue Yusuke, Sasaki Kazumasu, Shiraishi Yasuyuki, Yambe Tomoyuki, Tadano Shigeru

    Proceedings of the ... Asian Pacific Conference on Biomechanics : emerging science and technology in biomechanics 2015 (8) 225-225 2015/09/16

    Publisher: The Japan Society of Mechanical Engineers

  29. Artificial Sphincter

    YAMBE Tomoyuki, SHIRAISHI Yasuyuki, MIURA Hidekazu

    The Journal of the Institute of Electronics, Information, and Communication Engineers 98 (4) 290-294 2015/04

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN:0913-5693

  30. Effect of Japanese traditional food material, Miso on the baroreflex sensitivity of the heart and artery during the audiovisual immersion

    (36) 84-90 2015/03

    Publisher: 中央味噌研究所

    ISSN:0289-8942

  31. The evaluation of motor characteristics of the total artificial heart by the change in the rotor to stator gap

    HAGIO YUUKI, MIURA HIDEKAZU, SHIRAISHI YASUYUKI, SHIGA TAKUYA, YAMADA AKIHIRO, TSUBOKO YUSUKE, SANO KYOSUKE, TAIRA YASUNORI, YAMBE TOMOYUKI

    Transactions of Japanese Society for Medical and Biological Engineering 53 (0) S198_02-S198_02 2015

    Publisher: Japanese Society for Medical and Biological Engineering

    DOI: 10.11239/jsmbe.53.S198_02  

    ISSN:1347-443X

    More details Close

    In the development of total artificial heart (TAH), we must design left and right pumps separately to achieve a proper flow balance. In this study, we designed a motor of pump to maintain right heat circulation and prototyped. The Motor was designed by using Assumptive Magnetic Flux Path Method. We made equivalent circuit by this method, and evaluated synthetic reluctance, magnetic flux of gap for the purpose of inhibiting magnetic saturation. We adopted structure of DC brushless, four poles and 12 slots. We assumed the pump efficiency was 50%.We set maximum amount of cardiac output was 10L/min, maximum pressure was 20mmHg when rotation number was 3000rpm.In measurement, we examined the effect of gap difference, we changed the gap was 1.0 mm and 1.5 mm respectively. Result of measurement, torque and speed constants was 55 mNm/A and 180 rpm/V, 51 mNm/A and 198 rpm/V when the gap difference was 1.0 mm and 1.5 mm respectively. We confirmed the characteristics of the motor tend to high torque when the gap is narrow. On the other hand, it tends to high revolution when the gap is wide.

  32. Examination of the transcutaneous transmission system with the internal energy storage system for artificial organs using shape memory alloy fiber

    Hidekazu Miura, Akihiro Yamada, Mohamed Omran Hashem, Yasuyuki Shiraishi, Sato Fumihiro, Tomoyuki Yambe, Hidetoshi Matsuki

    Transactions of Japanese Society for Medical and Biological Engineering 52 98-O-99 2014/08/17

    Publisher: Japan Soc. of Med. Electronics and Biol. Engineering

    DOI: 10.11239/jsmbe.52.O-98  

    ISSN:1347-443X 1881-4379

    More details Close

    Artificial organs using shape memory alloy (SMA) fibers have possibilities to achieve small size and simple control. However, there is a problem of the instant heavy load in this paper we propose an efficient transcutaneous energy transmission system for SMA fibered devices. In this system, the internal storage capacitor is charged slowly while the fibers are turned off and discharge the energy when the fibers are turned on. We examined the effect of the system. Firstly we changed capacitance from 500uF to 34100uF. Secondly we changed input current limitation. There is possibility that the size and maximum output of the TETS would able to be reduced with the internal energy storage system.

  33. 2C25 Nonclinical animal studies for medical devices research in Tohoku University

    SHIRAISHI Yasuyuki, YAMBE TOMOYUKI, MIURA Hidekazu, AKIYAMA Masatoshi, SAIKI Yoshikatsu

    2014 (26) 355-356 2014/01/10

    Publisher: The Japan Society of Mechanical Engineers

  34. 2D45 Contactless measurement of peripheral perfusion by using a CCD camera

    SANO Kyosuke, KITANO Tomoya, SHIRAISHI Yasuyuki, TANAKA Aakira, YOSHIZAWA Makoto, YAMBE Tomoyuki

    2014 (26) 429-430 2014/01/10

    Publisher: The Japan Society of Mechanical Engineers

  35. 2C45 Mechanical modeling approach for the development of peristaltic artificial esophagus

    TAIRA Yasunori, KAMIYA Kurodo, SHIRAISHI Yasuyuki, HOMMA Dai, YAMBE Tomoyuki

    2014 (26) 383-384 2014/01/10

    Publisher: The Japan Society of Mechanical Engineers

  36. Autonomic function of the cardiovascular system in the subjects with functional food intake

    30 276-280 2014

    Publisher: 飯島藤十郎記念食品科学振興財団

    ISSN:2188-0662

  37. HEMODYNAMIC EFFECTS IN THE ATRIAL CONTRACTION MODEL ON THE TOTAL ARTIFICIAL HEART USING CENTRIFUNGAL BLOOD PUMPS WITH ADULT GOATS

    T. Shiga, H. Miura, Y. Shiraishi, M. Yamauchi, T. Yambe

    INTENSIVE CARE MEDICINE 39 S365-S365 2013/10

    Publisher: SPRINGER

    ISSN:0342-4642

    eISSN:1432-1238

  38. Helical flow total artificial heart with rotary blood pump control using autonomic nerve information

    243 (5) 485-493 2012/11/03

    Publisher: 医歯薬出版

    ISSN:0039-2359

  39. Peripheral Vascular Resistances During Total Left Heart Bypass with an Oscillated Blood Flow (vol 23, pg 747, 1999)

    T. Yambe, Satoyuki Kawano, S. Nanka

    ARTIFICIAL ORGANS 36 (6) 573-573 2012/06

    Publisher: WILEY-BLACKWELL

    DOI: 10.1111/j.1525-1594.2012.01500.x  

    ISSN:0160-564X

  40. 左心房収縮と流入血による渦の発生

    山家智之, 亀山剛義, 秋野能久, 西條芳文, 田中元直

    日本臨床生理学会雑誌 42 (5) 2012

    ISSN:0286-7052

  41. Blood Flow Structure in Patients with Dilated Cardiomyopathy Studied using Echo-dynamography

    亀山剛義, 山家智之, 白石泰之, 西條芳文, 田中元直

    日本臨床生理学会雑誌 42 (3) 2012

    ISSN:0286-7052

  42. Preliminary study on the effect of extra-cardiac conduit contractile pressure on the mechanical Fontan circulation support

    YAMADA Akihiro, SHIRAISHI Yasuyuki, SUGAI Telma Keiko, MIURA Hidekazu, SHIGA Takuya, HASHEM Mohamed Omran, KOGA Chihiro, HASHIMOTO Hisashi, TSUBOKO Yusuke, YAMBE Tomoyuki, YAMAGISHI Masaaki, HOMMA Dai

    2011 (67) 41-44 2011/11/24

  43. NEW ARTIFICIAL INTERNAL ORGAN TO CONTROL ATRIAL FIBRILLATION

    T. Yambe, Y. Shraishi, T. Sumiyoshi, H. Miura

    INTERNATIONAL JOURNAL OF ARTIFICIAL ORGANS 34 (8) 670-670 2011/08

    Publisher: WICHTIG EDITORE

    ISSN:0391-3988

  44. ARTIFICIAL MUSCLE FOR THE ACTUATOR OF THE ARTIFICIAL INTERNAL ORGANS

    T. Yambe, Y. Shiraishi, H. Miura, M. Akiyama, Y. Saiki, T. K. Sugai

    INTERNATIONAL JOURNAL OF ARTIFICIAL ORGANS 34 (8) 613-613 2011/08

    Publisher: WICHTIG EDITORE

    ISSN:0391-3988

  45. 8F-07 Preliminary study on the effect of papillary tension on valvular leakage for the development of a new artificial papillary muscle using shape memory alloy fiber

    HASHIMOTO Hisashi, SHIRAISHI Yasuyuki, SUGAI Telma KEIKO, KONNO Satoshi, MIURA Hidekazu, SAIJO Yoshifum, YAMBE Tomoyuki, HOMMA Dai

    2010 (23) 109-110 2011/01/07

    Publisher: The Japan Society of Mechanical Engineers

  46. 東日本大震災における人工臓器医工学

    山家 智之, 吉澤 誠, 柴田 宗一

    ナノ医工学年報 5 (1) 221-230 2011

    Publisher: 東北大学グローバルCOEプログラム「新世紀世界の成長焦点に築くナノ医工学拠点」

    ISSN:1882-4692

  47. 体外からのエネルギー伝送による超小型化補助循環装置の開発

    早津幸弘, 白石泰之, 秋山正年, 齋木佳克, 山家智之

    General Thoracic and Cardiovascular Surgery 59 (Supplement) 2011

    ISSN:1863-6705

  48. Preliminary study on the development of a new artificial papillary muscle using shape memory alloy fiber

    HASHIMOTO Hisashi, SHIRAISHI Yasuyuki, SUGAI Telma Keiko, KONNO Satoshi, MIURA Hidekazu, SAIJO Yoshifum, YAMBE Tomoyuki, HOMMA Dai

    2010 (45) 13-16 2010/11/20

  49. DIET CONTROL EXPANDING CAPSULE USING TRANSCUTANEOUS ENERGY TRANSMISSION

    T. Yambe, Y. Shiraishi, H. Miura, Y. Saiki, K. Fukushima, M. Yoshizawa

    INTERNATIONAL JOURNAL OF ARTIFICIAL ORGANS 33 (7) 455-455 2010/07

    Publisher: WICHTIG EDITORE

    ISSN:0391-3988

  50. AUTOMOBILE AS THE NEW TREATMENT SYSTEM FOR THE HYPERTENSION

    T. Yambe, R. Kawashima, M. Munakata, M. Yoshizawa

    JOURNAL OF HYPERTENSION 28 E540-E541 2010/06

    Publisher: LIPPINCOTT WILLIAMS & WILKINS

    ISSN:0263-6352

  51. Development of an Artificial Organs and the new diagnosis tool of Pulse wave (Annals of nano BME)

    Tomoyuki Yambe

    Annals of nano BME 3 197-208 2010/03

  52. 寸口脈の科学性 (経絡治療)

    山家智之

    経絡治療 180 12-13 2010/02/25

  53. 0406 Preliminary examination of an engineering control for hemodynamic assistance by the artificial myocardium using shape memory alloy fibre

    SATO Yuta, UMEZU Mitsuo, FUJIMOTO Tatsuo, SHIRAISHI Yasuyuki, MIURA Hidekazu, KONNO Satoshi, YAMBE Tomoyuki, KANEKO Yoshikazu, SUGAI Telma Keiko, YABE Shota, SAIJO Yoshifumi, BABA Atsushi, Homma Dai

    2009 (22) 58-58 2010/01/08

    Publisher: The Japan Society of Mechanical Engineers

  54. Bulging sinusを有するePTFE心臓代用弁の工学的評価

    白石泰之, 鈴木一郎, 矢部翔太, SUGAI Telma K, 山田昭博, 亀山剛義, 金子芳一, 北野智哉, 田中隆, 金野敏, 西條芳文, 梅津光生, 宮崎隆子, 山岸正明, 山家智之

    人工臓器(日本人工臓器学会) 39 (2) 2010

    ISSN:0300-0818

  55. 遠心血液ポンプのin vitro抗血栓性試験法:試験血液の影響

    丸山修, 小阪亮, 西田正浩, 筒井達夫, 井街宏, 山家智之, 山根隆志

    人工臓器(日本人工臓器学会) 39 (2) 2010

    ISSN:0300-0818

  56. Effect of Feedback of Zeroed Doppler Velocity on Ultrasonic-Measurement-Integrated Simulation of Blood Flow

    Funamoto Kenichi, Hayase Toshiyuki, Saijo Yoshifumi, Yambe Tomoyuki

    2010 216-216 2010

    Publisher: 日本流体力学会

    More details Close

    Ultrasonic-measurement-integrated (UMI) simulation, in which feedback signals are applied to the governing equations based on errors between ultrasonic measurement and numerical simulation, has been investigated for reproduction of the blood flow field. In this study, the effects of wall filter and lack of data, which provide zero Doppler velocity, on UMI simulation were examined by a numerical experiment dealing with the blood flow field in the descending aorta with an aneurysm. Effects of wall filter and lack of data appeared in diastole and in the whole period, respectively. However, by not adding feedback signals where measured Doppler velocities were zero, the computational accuracy of the UMI simulation substantially improved for the sake of the feedback.

  57. 形状記憶合金を用いた人工食道アクチュエータの蠕動運動特性評価

    三木寛之, 奥山武志, 小平真吾, LUO Yun, 高木敏行, 山家智之, 佐藤武志

    東北大学流体科学研究所報告 20 2010

    ISSN:0916-2860

  58. Sendai-Cluster : for advanced preventive-based community health

    YAMBE Tomoyuki, YOSHIZAWA Makoto

    46 (6) 617-618 2009/12/15

    ISSN:0288-9250

  59. A102 Evaluation of hemodynamic characteristics of the newly designed paediatric pulmonary heart valve by using a high speed video camera

    YABE Shota, SUZUKI Ichiro, Sugai Telma Keiko, SAIJO Yosifumi, MIURA Hidekazu, LIU Hong Jian, KONNO Satoshi, SHIRAISHI Yasuyuki, YAMBE Tomoyuki, TANAKA Takashi, UMEZU Mitsuo, MIYAZAKI Takako, YAMAGISHI Masaaki

    Proceedings of the ... JSME Conference on Frontiers in Bioengineering 2009 (20) 5-6 2009/11/06

    Publisher: The Japan Society of Mechanical Engineers

    ISSN:1348-2939

  60. B213 Blood Flow Simulation Integrated with Ultrasonic Measurement 9^<th> Report : Effect of Noise in Ultrasonic Measurement

    FUNAMOTO Kenichi, HAYASE Toshiyuki, SAIJO Yoshifumi, YAMBE Tomoyuki

    Proceedings of the ... JSME Conference on Frontiers in Bioengineering 2009 (20) 117-118 2009/11/06

    Publisher: The Japan Society of Mechanical Engineers

    ISSN:1348-2939

  61. Basic study on the sophisticated control for the intelligent artificial myocardium

    SHIRAISHI Yasuyuki, MIURA Hidekazu, YAMBE Tomoyuki, SUGAI Telma Keiko, SAIJO Yoshifumi, SATO Yuta, FUJIMOTO Tetsuo, UMEZU Mitsuo, BABA Atsushi, FUKUNAGA Kazuyoshi, TANAKA Akira, HOMMA Dai

    2009 (34) 37-42 2009/10/20

  62. Preliminary study on novel centrifugal blood pump for total artificial heart

    MIURA Hidekazu, SHIRAISHI Yasuyuki, YABE Shota, SUGAI Telma Keiko, LIU Hong Jian, YAMBE Tomoyuki

    2009 (34) 33-36 2009/10/20

  63. 510 Preliminary study on total artificial heart using rotary blood pumps

    MIURA Hidekazu, SHIRAISHI Yasuyuki, YABE Shota, SUGAI Telma Keiko, LIU Hong Jian, YAMBE Tomoyuki

    2009 (45) 147-148 2009/09/26

    Publisher: The Japan Society of Mechanical Engineers

  64. 509 Basic characteristics of the newly designed paediatric pulmonary circulatory simulator

    YABE Shota, SUZUKI Ichiro, SUGAI Telma Keiko, SAIJO Yosifumi, MIURA Hidekazu, LIU Hong Jian, KONNO Satoshi, SHIRAISHI Yasuyuki, YAMBE Tomoyuki, TANAKA Takashi, UMEZU Mitsuo, MIYAZAKI Takako, YAMAGISHI Masaaki

    2009 (45) 145-146 2009/09/26

    Publisher: The Japan Society of Mechanical Engineers

  65. 508 Preliminary study on the new bioengineering approach for surgical planning of ventricular reconstruction

    SHIRAISHI Yasuyuki, LIN Hui, SUGAI Telma Keiko, UEMATSU Miyuki, SAIJO Yoshifumi, TANAKA Akira, UMEZU Mitsuo, YAMBE Tomoyuki, TABAYASHI Koichi

    2009 (45) 143-144 2009/09/26

    Publisher: The Japan Society of Mechanical Engineers

  66. 自動車による自律神経機能アクチュエーション (電気学会産業応用部門論文集)

    山家智之, 吉沢誠

    電気学会産業応用部門論文集 97-102 2009/08

  67. 多次元の血圧反射機能感受性定量診断 (心臓リハビリテーション)

    山家智之, 金野敏, 西條芳文, 白石泰之, 仁田新一, 上月正博, 吉澤誠, 杉田典大, 田中明, 山口済, 片平美明, 秋野能久, 柴田宗一, 渡辺誠, 三引義明, 大沢上, 佐藤尚

    心臓リハビリテーション 14 (1) 108-114 2009/02

  68. 139 Mechanical design of the totally implantable artificial myocardial assist device by using shape memory alloy fibre

    SHIRAISHI Yasuyuki, SAKATA Ryo, SATO Yuta, KONNO Satoshi, SUGAI Telma Keiko, BABA Atsushi, FUJIMOTO Tetsuo, UMEZU Mitsuo, IMACHI Kou, SAIJO Yoshifumi, YAMBE Tomoyuki, Homma Dai

    2008 (21) 307-308 2009/01/22

    Publisher: The Japan Society of Mechanical Engineers

  69. 326 Blood Flow Simulation Integrated with Ultrasonic Measurement 8th Report : Effect of Error in Ultrasonic Measurement

    FUNAMOTO Kenichi, HAYASE Toshiyuki, SAIJO Yoshifumi, YAMBE Tomoyuki

    2008 (21) 353-354 2009/01/22

    Publisher: The Japan Society of Mechanical Engineers

  70. 脈のない人工心臓と脈の診断 (宮城県医師会報)

    山家智之

    宮城県医師会報 755 928-933 2008/12

  71. 1E3-5 Improvement of the artificial myocardial assistance for chronic animal experiment

    SATO Yuta, SHIRAISHI Yasuyuki, SAKATA Ryo, LIN Hui, TANAKA Takashi, UMEZU Mitsuo, KONNO Satoshi, SAIJO Yoshifumi, SUGAI Telma Keiko, YOSHIZAWA Makoto, YAMBE Tomoyuki, BABA Atsushi, MASUMOTO Noriyasu, FUJIMOTO Tetsuo, Homma Dai

    The JSME Symposium on Welfare Engineering 2008 135-136 2008/09/17

    Publisher: The Japan Society of Mechanical Engineers

  72. ARTIFICIAL ESOPHAGUS PROJECT

    T. Yambe, K. Imachi, Y. Shiraishi, G. Miyata, S. Satomi

    INTERNATIONAL JOURNAL OF ARTIFICIAL ORGANS 31 (7) 657-657 2008/07

    Publisher: WICHTIG EDITORE

    ISSN:0391-3988

  73. 埋め込み型補助人工心筋開発 (電気学会技術報告)

    山家智之

    電気学会技術報告 1122 48-49 2008/07

  74. 動脈系血圧反射機能感受性診断法の発明 (電気学会技術報告)

    山家智之

    電気学会技術報告 1112 49-51 2008/07

  75. 脈診に科学的根拠はあるか? (日本統合医療学会誌)

    山家智之

    日本統合医療学会誌 1 (1) 71-78 2008/07

  76. 統合医療の医工学的評価と今後の展開 鍼が循環系に及ぼす影響の制御工学的解釈 (日本統合医療学会誌)

    吉澤誠, 関隆志, 杉田典大, 阿部誠, 田中明, 金野敏, 山家智之, 仁田新一, 川田浩

    日本統合医療学会誌 1 (1) 28-32 2008/07

  77. 科学技術振興調整費プロジェクトを中心とした統合医療・代替医療の科学的評価研究の現状 (日本統合医療学会誌)

    仁田新一, 金野敏, 山家智之, 関隆志, 杉田典大, 吉澤誠

    日本統合医療学会誌 1 (1) 19-22 2008/07

    Publisher: 日本統合医療学会

  78. Effect of the mechanical support system assistance on the arterial elasticity - Prevention of the atherosclerosis and hypertension

    T. Yambe, Y. Abe, K. Tabayashi, E. Okamoto, Y. Shiraishi

    JOURNAL OF HYPERTENSION 26 S437-S438 2008/06

    Publisher: LIPPINCOTT WILLIAMS & WILKINS

    ISSN:0263-6352

  79. 脳波・筋電図の臨床 多変数制御装置としての循環中枢 心拍数調節と血管抵抗調節の役割分担 (臨床脳波)

    吉澤誠, 杉田典大, 阿部誠, 田中明, 山家智之, 仁田新一

    臨床脳波 50 (6) 347-353 2008/06

    Publisher: 永井書店

    ISSN:0485-1447

  80. 日本製臨床用遠心型埋め込み式補助人工心臓の世界最長動物実験 (東北医学雑誌)

    山家智之, 白石泰之, 羅雲, 井街宏, 山崎健二, 北野智哉, 山崎俊一

    東北医学雑誌 120 (1) 77-79 2008/06

    ISSN:0040-8700

  81. Oxygenation to Bovine Blood in Artificial Heart and Lung Using Vibrating Flow Pump

    SHINTAKU Hirofumi, YONEMURA Tsubasa, ISOYAMA Takashi, YAMBE Tomoyuki, KAWANO Satoyuki

    Transactions of the Japan Society of Mechanical Engineers B 74 (740) 862-870 2008/04/25

    Publisher: The Japan Society of Mechanical Engineers

    ISSN:0387-5016

    More details Close

    We had developed the vibrating flow pump (VFP) for left ventricular assist device based on the fluid dynamical analysis and the animal tests. The main advantages of VFP were generating the oscillated blood flow and having simple mechanical structure. In this study, we constructed an experimental apparatus for a prototype artificial heart and lung by means of installing hollow fibers into the vibrating tube in the VFP. The characteristics of gas exchange were investigated both by experiment using bovine blood and by numerical analysis. The unsteady, incompressible, and axisymmetric Navier-Stokes equations and diffusion equation were solved based on finite difference technique. In the prototype VFP, the effect of the oscillated flow on the gas exchange was relatively small in the range of Reynolds number of O(1)〜O(1000). Comparing experimental and numerical results, we discussed the validity of the numerical analysis and predicted the characteristics of the VFP. The basic design data of VFP installing hollow fibers were accumulated for the artificial heart and lung.

  82. 115 Heat Transfer Control of Thermotherapy by Using Abdominal Heating Controller

    TAKASHIMA Shigeru, MARUYAMA Shigenao, KOMIYA Atsuki, OGASAWARA Naoya, SEKI Takashi, YAMBE Tomoyuki

    2008 (43) 31-32 2008/03/15

    Publisher: The Japan Society of Mechanical Engineers

  83. ナノテクノロジーの人工内臓開発への応用 (Proceeding of clinical electron microscopy)

    山家智之

    Proceeding of clinical electron microscopy 27 1-3 2008/03

  84. Development of the Super stent system for Esophageal carcinoma (Nano Biomedical Engineering in the East Asian pacific Rim Region)

    Yambe T, Shiraishi S, Sato F, Miyata G, Satomi S, Matsuki H, Yoshizawa M

    Nano Biomedical Engineering in the East Asian pacific Rim Region 15-18 2008/03

  85. ナノテク人工心筋開発 (循環器専門医)

    山家智之, 白石泰之, 田林晄一

    循環器専門医 16 (1) 75-81 2008/03

    DOI: 10.1253/jjcsc.16.1_75  

  86. 新たなるナノテクノロジーとは? ナノテク人工心筋開発 (循環器専門医)

    山家智之, 白石泰之, 田林晄一

    循環器専門医 16 (1) 75-81 2008/03

    DOI: 10.1253/jjcsc.16.1_75  

  87. 「統合医療の評価」「私達の身体は統合医療を求めている」 工学的アプローチによる統合医療の評価 自律神経系指標ρmaxの適用例 (日本統合医療学会誌)

    吉澤誠, 関隆志, 杉田典大, 阿部誠, 田中明, 金野敏, 川田浩, 山家智之, 仁田新一

    日本統合医療学会誌 4 (1月2日) 60-64 2008/02

    Publisher: 日本統合医療学会

  88. 637 Mechanical analysis of morphological structure of a heart for more sophisticated design of the artificial myocardium

    SHIRAISHI Yasuyuki, SAIJO Yoshifumi, YAMBE Tomoyuki, SHIBATA Muneichi, WADA Yumiko, SAKATA Ryo, WATABE Tomoki, UMEZU Mitsuo, FUJIMOTO Tetsuo, BABA Atsushi, TABAYASHI Koichi, Homma Dai

    2007 (20) 433-434 2008/01/24

    Publisher: The Japan Society of Mechanical Engineers

  89. 115 Numerical Simulation of Blood Flow in Left Atrium Modeled with Magnetic Resonance Imaging

    KANKE Yusuke, HAYASE Toshiyuki, YAMBE Tomoyuki, SHIBATA Muneichi, SHIRAISHI Yasuyuki

    2007 (20) 29-30 2008/01/24

    Publisher: The Japan Society of Mechanical Engineers

  90. MERAモノピボット遠心血液ポンプの血液適合性評価

    丸山修, 吉田文彦, 矢田亨, 小阪亮, 西田正浩, 山本好宏, 桑名克之, 白石泰之, 山家智之, 馬場敦, 井街宏, 筒井達夫, 山根隆志

    人工臓器(日本人工臓器学会) 37 (2) 2008

    ISSN:0300-0818

  91. Biomimetic artificial myocardium using nano technology (Future Medical Engineering based on Bionanotechnology)

    Yambe T

    Future Medical Engineering based on Bionanotechnology 281-294 2007/12

  92. ナノテクノロジーの人工内臓開発への応用 (Proceedings of Clinical Electron Microscopy)

    山家智之

    Proceedings of Clinical Electron Microscopy 27 1-3 2007/12

  93. A111 Mechanical simulation for myocardial contractile assistance based on controllability of a sophisticated shape memory alloy fibre

    SAKATA Ryo, SHIRAISHI Yasuyuki, WADA Yumiko, WATABE Tomoki, UEMATSU Miyuki, TANAKA Takashi, PARK Young Kwang, UMEZU Mitsuo, SEKINE Kazumitsu, KONNO Satoshi, SAIJO Yoshifumi, YAMBE Tomoyuki, TANAKA Akira, YOSHIZAWA Makoto, MASUMOTO Noriyasu, FUJIMOTO Tetsuo, HOMMA Dai

    Proceedings of the ... JSME Conference on Frontiers in Bioengineering 2007 (18) 21-22 2007/10/05

    Publisher: The Japan Society of Mechanical Engineers

    ISSN:1348-2939

  94. Pulse wave velocity during circulatory assistance with undulation pump ventricular assist device (UPVAD)

    T. Yambe, Y. Luo, M. Yoshizawa, S. Nitta, K. Imachi, Y. Abe

    INTERNATIONAL JOURNAL OF ARTIFICIAL ORGANS 30 (8) 736-736 2007/08

    Publisher: WICHTIG EDITORE

    ISSN:0391-3988

  95. New artificial organ = Hyperthermia drinking stent

    T. Yambe, Y. Shiraishi, K. Sekine, G. Miyata, S. Satomi

    INTERNATIONAL JOURNAL OF ARTIFICIAL ORGANS 30 (8) 736-736 2007/08

    Publisher: WICHTIG EDITORE

    ISSN:0391-3988

  96. 脳神経機能制御アクチュエータ (電気学会産業技術応用部門講演会論文集)

    山家智之, 白石泰之, 圓山重直

    電気学会産業技術応用部門講演会論文集 33-36 2007/08

  97. New quantitative diagnosis machine for the baroreflex sensitivity of the heart and the artery

    T. Yambe, M. Munakata, K. Tabayashi, M. Yoshizawa, A. Tanaka, N. Sugita

    JOURNAL OF HYPERTENSION 25 S303-S303 2007/06

    Publisher: LIPPINCOTT WILLIAMS & WILKINS

    ISSN:0263-6352

  98. 213 CFD Study on Control of Oxigen Concentration in Vibrating Flow Blood Pump for Artificial Heart

    YONEMURA Tsubasa, KAWANO Satoyuki, Shintaku Hirofumi, ISOYAMA Takashi, YAMAIE Tomoyuki

    2007 (82) "2-15" 2007/03/16

    Publisher: The Japan Society of Mechanical Engineers

  99. 309 Blood Flow Simulation Integrated with Ultrasonic Measurement : 7^<th> Report: Effect of Time Resolution of Measurement

    FUNAMOTO Kenichi, HAYASE Toshiyuki, SAIJO Yoshifumi, YAMBE Tomoyuki

    2006 (19) 68-69 2007/01/06

    Publisher: The Japan Society of Mechanical Engineers

  100. 体内埋込み機器のための始動トリガの簡易的な伝送に関する検討

    角張泰之, 佐藤文博, 松木英敏, 関根一光, 白石泰之, 山家智之, 佐藤忠邦

    電気関係学会東北支部連合大会講演論文集 2007 2007

  101. 人工心筋収縮構造制御による補助効率最適化に関する基礎検討

    白石泰之, 山家智之, 関根一光, 西條芳文, 金野敏, 仁田新一, 和田由美子, 坂田亮, 梅津光生, 小川大祐, 佐藤文博, 角張泰之, 田中明, 吉澤誠, 本間大

    日本生体医工学会大会プログラム・論文集(CD-ROM) 46th 2007

  102. 蠕動運動機能をもつ人工食道のための胃部留置型経皮的電力伝送装置の開発

    角張泰之, 佐藤文博, 松木英敏, 関根一光, 白石泰之, 山家智之, 佐藤忠邦

    日本生体医工学会大会プログラム・論文集(CD-ROM) 46th 2007

  103. 形状記憶合金を応用した消化管蠕動運動補助装置

    関根一光, 山家智之, 西條芳文, 白石泰之, 松木英敏, 佐藤文博, 角張泰之, 前田剛, 中澤文男

    日本生体医工学会大会プログラム・論文集(CD-ROM) 46th 2007

  104. 生体心臓の構造を考慮した人工心筋開発の試み

    白石泰之, 山家智之, 関根一光, 西條芳文, 金野敏, 仁田新一, 和田由美子, 坂田亮, 伊藤慎二, 植松美幸, PARK Youngkwang, 田中隆, 梅津光生, 小川大祐, 角張泰之, 佐藤文博, 田中明, 吉澤誠, 増本憲泰, 藤本哲男, 本間大, 馬場敦, 井街宏, 佐々田比呂志, 田林晄一

    バイオエンジニアリング講演会講演論文集 19th 2007

    ISSN:1348-2920

  105. Ultrasound speed and impedance microscopy for in vivo imaging. International-journal

    Yoshifumi Saijo, Naohiro Hozumi, Kazuto Kobayashi, Nagaya Okada, Toshimichi Ishiguro, Yoshihiro Hagiwara, Esmeraldo dos Santos Filho, Tomoyuki Yambe

    Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference 2007 1350-3 2007

    ISSN:1557-170X

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    Ultrasound speed and impedance microscopy was developed in order to develop in vivo imaging system. The sound speed mode realized non-contact high resolution imaging of cultured cells. This mode can be applied for assessment of biomechanics of the cells and thinly sliced tissues. The impedance mode visualized fine structures of the surface of the rat's brain. This mode can be applied for intra-operative pathological examination because it does not require slicing or staining.

  106. B102 Design improvement of a newly designed artificial myocardial belt

    WADA Yumiko, SHIRAISHI Yasuyuki, ITOH Shinji, SAKATA Ryo, UEMATSU Miyuki, TANAKA Takashi, PARK Young Kwang, UMEZU Mitsuo, SEKINE Kazumitsu, KONNO Satoshi, SAIJO Yoshifumi, YAMBE Tomoyuki, Nitta Shinichi, TANAKA Akira, YOSHIZAWA Makoto, MASUMOTO Noriyasu, FUJIMOTO Tetsuo, HOMMA Dai

    Proceedings of the ... JSME Conference on Frontiers in Bioengineering 2006 (17) 43-44 2006/11/10

    Publisher: The Japan Society of Mechanical Engineers

    ISSN:1348-2939

  107. 814 Artificial Organs by the use of Nano Technology(2)

    YAMBE Tomoyuki

    Fluids engineering conference ... 2006 "814-1"-"814-4" 2006/10/28

    Publisher: The Japan Society of Mechanical Engineers

    ISSN:1348-2882

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    Of course, the space in the human body was limited, so, micro machining technology and the nano technology are the important tools for the development of the various kinds of internal artificial organs. Surface finishing technology with nano level DNA coating, various kinds of nano sensing devices including optical fiber sensor with nano size diaphragm and diamond like carbon nano film, nano actuator, and transcutaneous energy transmission system with nano particle magnetic shielding technology are the common useful technology for the development of various kinds of artificial implantable organs. By the use of these common technologies, circulatory assist systems including total artificial heart with undulation pump, ventricular assist device including rotary blood pump and artificial myocardium, artificial esophagus, drinking stent with peristaltic movements using SMA actuator with nano technology, artificial sphincter and epilepsy control machine are now under development. In this paper, various kinds of artificial internal organs by the use of nano technology are introduced and discussed.

  108. 814 Artificial Organs by the use of Nano Technology(1)

    YAMBE Tomoyuki

    Fluids engineering conference ... 2006 "814-a" 2006/10/28

    Publisher: The Japan Society of Mechanical Engineers

    ISSN:1348-2882

  109. 1306 Numerical Experiment of Ultrasonic-Measurement-Integrated Simulation for Three-Dimensional Unsteady Blood Flow(1)

    FUNAMOTO Kenichi, HAYASE Toshiyuki, SAIJO Yoshifumi, YAMBE Tomoyuki

    Fluids engineering conference ... 2006 "1306-a" 2006/10/28

    Publisher: The Japan Society of Mechanical Engineers

    ISSN:1348-2882

  110. Development of peristaltic motion assist device for using helicoidal shape memory alloy against digestive organs cancer

    SEKINE Kazumitsu, YAMBE Tomoyuki, SHIRAISHI Yasuyuki, SAIJO Yoshifumi, HORI Yoshio, MATSUKI Hidetoshi, SATO Fumihiro, NITTA Shin-ichi, MAEDA Tsuyoshi

    2006 (48) 69-73 2006/10/26

  111. Fluid Power System and Artificial Heart, Circulatory Assist, and Artificial Myocardium

    YAMBE Tomoyuki

    Journal of the Japan Fluid Power System Society 37 (5) 310-313 2006/09/15

    Publisher: 日本フルードパワーシステム学会

    ISSN:1346-7719

  112. 統合医療における医工学の役割 自律神経活動の解析を中心とした医工学的評価方法の開発 (日本統合医療学会誌)

    仁田新一, 金野敏, 川田浩, 山家智之, 関隆志, 荒井啓行, 杉田典大, 吉澤誠

    日本統合医療学会誌 3 (1) 31-37 2006/08

    Publisher: 日本統合医療学会

  113. 癌を治療し,食物を飲み込む「超」消化管ステントシステム (東北医学雑誌)

    山家智之, 宮田剛, 堀義生

    東北医学雑誌 118 (1) 58-60 2006/06

  114. 21 COE artificial organ project using regenerative medicine and nano technology : In artificial internal organs, smaller is better. And an important issue is bio affinity. From these points of view, Regenerative medicine and Nano technology are very useful technology. In Tohoku University, various artificial internal organ research including Artificial esophagus, Artificial Myocardium, and Artificial sphincter based on 21 COE program. Ideal artificial organs may be embodied in future

    YAMBE Tomoyuki, HORI Yoshio, SHIRAISHI Yasuyuki, SEKINE Kazumitsu, IGUCHI Atsushi, TABAYASHI Kouichi, HAGA Youichi, ESASHI Masayoshi, YOSHIZAWA Makoto, TANAKA Akira, MATSUKI Hidetoshi, SATO Fumihiro, KAWANO Satoyuki, LUO Yun, HIGA Masaru, TAKAGI Toshiyuki, HAYASE Toshiyuki, MARUYAMA Shigenao, WANG Quintian, DHUANG Kyokuto, NITTA Shinichi, IMACHI Kou, SASADA Hiroshi, SATO Eimei, SATO Masaaki, OKAMOTO Eiji, KUBO Yutaka, OSAKA Motohisa, UMETSU Mitsuo, HONMA Dai, MAEDA Takeshi

    Ensho Saisei 26 (1) 35-39 2006/01/25

    Publisher: The Japanese Society of Inflammation and Regeneration

    DOI: 10.2492/jsir.26.35  

    ISSN:1346-8022

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    In artificial internal organs, smaller is better. And an important issue is bio affinity. From these points of view, Regenerative medicine and Nano technology are very useful technology. In Tohoku University, various artificial internal organ research including Artificial esophagus, Artificial Myocardium, and Artificial sphincter based on 21 COE program. Ideal artificial organs may be embodied in future.

  115. 223 Effect of Anisotropic Feedback Points Arrangement in Three-dimensional Ultrasonic-Measurement-Integrated Simulation

    FUNAMOTO Kenichi, HAYASE Toshiyuki, SAIJO Yoshifumi, YAMBE Tomoyuki

    2005 (18) 105-106 2006/01/12

    Publisher: The Japan Society of Mechanical Engineers

  116. 人工肛門括約筋の経皮駆動システムの試作

    角張泰之, 三浦英和, 佐藤文博, 松木英敏, 佐藤忠邦, 比嘉昌, LUO Yun, 山家智之

    日本生体医工学会大会プログラム・論文集 45th 2006

    ISSN:1347-443X

  117. 経食道心エコーによる左室補助装置装着患者の心機能評価

    西條芳文, 齋木佳克, 井口篤志, 田林晄一, 白石泰之, 関根一光, 山家智之

    日本生体医工学会大会プログラム・論文集 45th 2006

    ISSN:1347-443X

  118. 左心補助装置装着症例の術中経食道心エコー所見

    西條芳文, 齋木佳克, 井口篤志, 田林晄一, 白石泰之, 関根一光, 山家智之

    日本心エコー図学会学術集会抄録集 17th 2006

  119. 502 Evaluation of an artificial esophagus with peristalsis using shape memory alloy

    YAMAGUCHI Mitsuyoshi, OKUYAMA Takeshi, TAKAGI Toshiyuki, YAMBE Tomoyuki, MIKI Hiroyuki

    The Proceedings of Conference of Tohoku Branch 2006 (0) 195-196 2006

    Publisher: The Japan Society of Mechanical Engineers

  120. LINEAR ACTUATION FOR AN ARTIFICIAL INTERNAL ORGANS WITH NANO TECHNOLOGY

    YAMBE Tomoyuki

    2005 (44) 1-4 2005/11/17

  121. ナノセンサを内蔵した癲癇発作停止装置

    山家 智之, 円山 重直, 高木 敏行, 松木 英敏

    人工臓器 34 (2) "S-21" 2005/11/15

    ISSN:0300-0818

  122. B117 Development of a totally-implantable artificial myocardium using a shape memory alloy fiber

    NAGATOSHI Jun, ITOH Shinji, UEMATSU Miyuki, TANAKA Takashi, UMEZU Mitsuo, SHIRAISHI Yasuyuki, SEKINE Kazumitsu, KONNO Satoshi, SAIJO Yoshifumi, YAMBE Tomoyuki, TANAKA Akira, YOSHIZAWA Makoto, MASUMOTO Noriyasu, FUJIMOTO Tetsuo, HOMMA Dai

    Proceedings of the ... JSME Conference on Frontiers in Bioengineering 2005 (16) 77-78 2005/11/08

    Publisher: The Japan Society of Mechanical Engineers

    ISSN:1348-2939

  123. B205 Blood Flow Simulation Integrated with Ultrasonic Measurement : 5^<th> Report: Reproduction of Three-dimensional Unsteady Blood Flow Field

    FUNAMOTO Kenichi, HAYASE Toshiyuki, SAIJO Yoshifumi, YAMBE Tomoyuki

    Proceedings of the ... JSME Conference on Frontiers in Bioengineering 2005 (16) 137-138 2005/11/08

    Publisher: The Japan Society of Mechanical Engineers

    ISSN:1348-2939

  124. 907 Evaluation of Effectiveness of Feedback Formulae in Three-dimensional Ultrasonic-Measurement-Integrated Simulation of Blood Flow

    Funamoto Kenichi, Hayase Toshiyuki, Saijo Yoshifumi, Yambe Tomoyuki

    Fluids engineering conference ... 2005 139-139 2005/10/28

    Publisher: The Japan Society of Mechanical Engineers

    ISSN:1348-2882

  125. 【消化管とナノテクノロジー医療】 ナノバイオマテリアルを応用した人工食道の開発 (G.I.Research)

    山家智之, 堀義生, 渡辺誠, 白石泰之, 井口篤志, 田林晄一, 芳賀洋一, 江刺正喜, 吉澤誠, 田中明, 松木英敏, 佐藤文博, 川野恭之, 羅雲, 高木敏行, 早瀬敏幸, 圓山重直, 仁田新一, 佐々田比呂志, 佐藤英明, 本間大, 前田剛

    G.I.Research 13 (4) 271-276 2005/08

  126. Intravascular Two-dimensional Tissue Velocity Imaging of Vulnerable Plaque(Intravascular Endoscopy/Intravascular Ultrasound 4 (I), The 69th Annual Scientific Meeting of the Japanese Circulation Society)

    Saijo Yoshifumi, Tanaka Akira, Hirosaka Akira, Yoshizawa Makoto, Akino Yoshihisa, Yambe Tomoyuki

    Circulation journal : official journal of the Japanese Circulation Society 69 245-246 2005/03/01

    Publisher: Japanese Circulation Society

    ISSN:1346-9843

  127. AM05-17-010 Effect of Feedback Points Arrangement on Accuracy of Three-dimensional Ultrasonic-Measurement-Integrated Simulation of Blood Flow

    Funamoto Kenichi, Hayase Toshiyuki, Saijo Yoshifumi, Yambe Tomoyuki

    2005 226-226 2005

    Publisher: 日本流体力学会

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    We have developed Ultrasonic-Measurement-Integrated (UMI) simulation to obtain detailed and accurate information of blood flow field numerically for the diagnosis or treatment of aneurysms. In this methodology, feedback signals derived from the difference between Doppler velocities by measurement and computation are fed back to the numerical simulation. In this study, we investigate the effect of feedback point arrangement on the computational accuracy of three-dimensional UMI simulation by numerical analysis. The result of UMI simulation converges to the standard solution in the feedback domain and in some extent of the downstream region of the feedback domain. The computational accuracy is more improved as the increment of feedback point density, while the necessary computational time for convergence is unchanged.

  128. 【生体情報とバイオニック医学】 生体情報を利用した人工心臓の循環制御 (循環制御)

    吉澤誠, 田中明, ポール・オレガリオ, 小川大祐, 阿部健一, 山家智之, 仁田新一

    循環制御 25 (4) 342-347 2004/12

  129. ナノテクノロジーによる人工臓器医工学の未来 (東北医学雑誌)

    山家智之

    東北医学雑誌 116 (2) 139-142 2004/12

  130. Introduction to Novel Development of Cooperation between Medical Science and Engineering(<Special Issue> on Novel Development of Cooperation between Medical Science and Engineering)

    YAMBE Tomoyuki, Tomoyuki YAMBE

    12 (2) 86-86 2004/11/30

    ISSN:0919-4452

  131. Blood Flow Simulation Integrated with Ultrasonic Measurement 3^<rd> Report : Reproduction of Three-dimensional Blood Flow Field

    FUNAMOTO Kenichi, HAYASE Toshiyuki, SAIJO Yoshifumi, YAMBE Tomoyuki

    Proceedings of the ... JSME Conference on Frontiers in Bioengineering 2004 (15) 113-114 2004/11/04

    Publisher: The Japan Society of Mechanical Engineers

    ISSN:1348-2939

  132. ITで可能となる新たな臨床検査の展開 (医療と検査機器・試薬)

    金野敏, 桑山貴志, 山家智之, 江刺正喜, 仁田新一

    医療と検査機器・試薬 27 (2) 59-66 2004/04

  133. Mayer波帯域における脈波伝播時間-心拍数間の相互相関を用いた情動反応の定量化 (循環制御)

    吉澤誠, 杉田典大, 田中明, 増田達哉, 阿部健一, 山家智之, 仁田新一

    循環制御 25 (1) 41-49 2004/03

    DOI: 10.11312/ccm.25.41  

    ISSN:0389-1844

  134. Ultrasonic-Measurement-Integrated Simulation for Blood Flows 2^<nd> Report : Reproduction of Blood Flow in Aorta

    FUNAMOTO Kenichi, HAYASE Toshiyuki, SHIRAI Atsushi, YAMBE Tomoyuki, SAIJO Yoshifumi

    2004 (16) 165-166 2004/01/21

    Publisher: The Japan Society of Mechanical Engineers

  135. B324 Study of Feedback Law for Ultrasonic-Measurement-Integrated Simulation of Blood Flow

    FUNAMOTO Kenichi, HAYASE Toshiyuki, SHIRAI Atsushi, SAIJO Yoshifumi, YAMBE Tomoyuki

    2004 538-539 2004

    Publisher: 日本流体力学会

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    In order to reproduce the blood velocity and pressure fields of the blood flow for an accurate diagnosis or treatment for serious circulatory diseases such as aortic aneurysms, we integrate color Doppler ultrasonography and numerical simulation. We term this method as Ultrasonic-Measurement-Integrated (UMI) simulation. In the UMI simulation, feedback signals are added to the governing equations to compensate for the difference between computation and measurement. In this paper, we investigate effects of feedback law of the UMI simulation, such as feedback formulae, number and arrangement of monitoring points and the direction of ultrasonic beam for acquisition of Doppler velocity data, on the accuracy of the UMI simulation and computational time. It is revealed that the result of UMI simulation in the feedback domain rapidly converges to the standard solution, even with inevitably incorrect upstream boundary conditions.

  136. 人工こう門括約筋の非接触安全駆動に関する検討

    角張泰之, 佐藤文博, 松木英敏, 佐藤忠邦, LUO Y, 高木敏行, 山家智之, 仁田新一

    日本ME学会大会論文集 43rd 2004

  137. Assessing a Simplified Analyzer of Physiological Indices for Reflecting Physiological and Psychological States in Virtual Spaces

    YOSHIZAWA Makoto, SUGITA Norihiro, TANAKA Akira, MASUDA Tatsuya, ABE Ken-ichi, YAMBE Tomoyuki, NITTA Shin-ichi

    Proceedings of the Virtual Reality Society of Japan,annual conference 8 311-314 2003/09/17

    Publisher: 日本バ-チャルリアリティ学会

    ISSN:1342-4564

  138. Electromagnetic Property of Temperature Control Transformer for Artificial Sphincter

    KAKUBARI Y., SATO F., MATSUKI H., SATO T., LUO Y., TAKAGI T., YAMBE T., NITTA S.

    27 544-544 2003/09/01

    ISSN:1340-8100

  139. Ultrasonic-Measurement-Integrated Simulation for Blood Flows : 1^<st> Report : Reduction of Error Originating from Upstream Boundary Condition

    FUNAMOTO Kenichi, HAYASE Toshiyuki, SHIRAI Atsushi, YAMBE Tomoyuki, SAIJO Yoshifumi

    Proceedings of the ... JSME Conference on Frontiers in Bioengineering 1 83-84 2003

    Publisher: The Japan Society of Mechanical Engineers

    ISSN:1348-2939

  140. Third Japan-Australia cardiovascular bioengineering symposium. (Artif Organs)

    Nitta Shin-Ichi, Yambe Tomoyuki

    Artif Organs 27 (1) 1-1 2003/01

    DOI: 10.1046/j.1525-1594.2003.00952.x  

  141. Circulatory Control of Continuous-Flow Artificial Hearts

    YOSHIZAWA Makoto, TANAKA Akira, OLEGARIO Paul, ABE Ken-ichi, TAKEDA Hiroshi, YAMBE Tomoyuki, NITTA Shin-ichi

    17 35-38 2002/09/09

  142. SMAを用いた人工こう門括約筋の非接触駆動に関する検討

    角張泰之, 井上雅弘, 佐藤文博, 松木英敏, 佐藤忠邦, 羅雲, 高木敏行, 山家智之, 仁田新一

    日本ME学会大会論文集 41st 2002

  143. Physiological evaluation of visual stimuli using cross-correlation coefficient from blood pressure to heart rate : Technical Report

    SUGITA Norihiro, YOSHIZAWA Makoto, TANAKA Akira, ABE Ken-ichi, YAMBE Tomoyuki, NITTA Shin-ichi

    Technical report of IEICE. HIP 101 (512) 31-34 2001/12/10

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN:0913-5685

    More details Close

    To find a new physiological index for quantitatively evaluation of the effect of visual stimuli on the human, blood pressure and heart rate of 33 subjects watching two or three dimensional video image were analyzed. The experiments have shown that the maximum cross-correlation coefficient ρ_<max> from blood pressure to heart rate, whose frequency components were limited to the neighborhood of 0.1Hz, could well reflect the human emotional reaction to visual stimuli. It has also significantly been shown that three dimensional display yielded smaller ρ_<max> than two dimensional one and that the subjects who previously reported proneness to motion sickness had smaller ρ_<max> than those who did not.

  144. Deterministic Chaos and Artificial Baroreflex System

    YAMBE Tomoyuki, NANKA Shunsuke, YOSHIZAWA Makoto, TANAKA Akira, TABAYASHI Kou-ichi, NITTA Shin-ichi

    31 (5) 261-264 2001/10/01

    ISSN:0286-7052

  145. Quantitative Assessment of Relationship between Proneness to Motion Sickness and Sensitivity to 3D Images

    SUGITA Norihiro, YOSHIZAWA Makoto, TANAKA Akira, ABE Ken-ichi, YAMBE Tomoyuki, NITTA Shin-ichi

    Proceedings of the Virtual Reality Society of Japan,annual conference 6 121-124 2001/09/19

    Publisher: 日本バ-チャルリアリティ学会

    ISSN:1342-4564

  146. Single-Beat Estimation of E_<max> Based on Both Linearity of Ventricular Elastance and Constancy of Ventricular Dead Volume

    YOSHIZAWA Makoto, YOKOGAWA Megumi, TANAKA Akira, ABE Ken-ichi, SAIJO Yoshifumi, YAMBE Tomoyuki, NITTA Shin-ichi, KASS David A.

    16 45-48 2001/08/29

  147. Noninvasive Estimation of E_<max> Based on Aortic Flow Automatically Extracted from Doppler Echocardiography

    HIKOSAKA Takahiro, YOSHIZAWA Makoto, TANAKA Akira, ABE Ken-ichi, SAIJO Yoshifumi, YAMBE Tomoyuki, NITTA Shin-ichi

    16 49-52 2001/08/29

  148. Outflow Control for Avoiding Atrial Suction in a Continuous-Flow TAH

    TANAKA Akira, YOSHIZAWA Makoto, ABE Ken-ichi, TAKEDA Hiroshi, YAMBE Tomoyuki, NITTA Shin-ichi

    16 231-234 2001/08/29

  149. Fluctuations in hemodynamic derivatives during left ventricular assistance by the use of the Vibrating flow pump

    YAMBE Tomoyuki, NANKA Shunsuke, TANAKA Akira, NITTA Shin-ichi, TABAYASHI Kou-ichi

    21 8-8 2001/03/25

    ISSN:0285-1660

  150. Thermomechanical Characteristics of An SMA Artificial Sphincter

    LUO Yun, TAKAGI Toshiyuki, HAYASHI Junko, MATSUZAWA Kenichi, YAMBE Tomoyuki, KAMIYAMA Takamichi, AMAE Shintaro, WADA Motoshi

    2001 (13) 148-149 2001/01/15

    Publisher: The Japan Society of Mechanical Engineers

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    This paper describes the development of a shape memory alloy (SMA) actuator as an artificial sphincter. The artificial sphincter is expected to enable the active bowel movement of patients without the function due to inborn intestinal atresia or medical operations of an artificial anus. The actuator has the functions of a valve; keeping the artificial anus closed at the body temperature and opening it by heating the SMAs. Investigations on thermomechanical properties of the actuator have been carried out.

  151. Estimation of Flow Rate and Pressure Difference of Continuous-Flow Artificial Hearts

    Yoshizawa Makoto, Yamada Tomoyuki, Tanaka Akira, Onodera Hiroaki, Takeda Hiroshi, Yambe Tomoyuki, Nitta Shinichi, Abe Kenichi

    2001 (13) 124-125 2001/01/15

    Publisher: The Japan Society of Mechanical Engineers

  152. Artificial Baroreflex System

    YAMBE Tomoyuki, ABE Yuusuke, IMACHI kou, TANAKA Akira, YOSHIZAWA Makoto, NITTA Shinichi

    2001 (13) 134-135 2001/01/15

    Publisher: The Japan Society of Mechanical Engineers

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    For the improvement of the quality of life of the patients with artificial heart system, it is important to detect the information of the circulatory regulatory system. Baroreflex system is an important control system when we consider the HOMEOSTASIS of the cardiovascular system. In this study, we studied an artificial baroreflex system using an electrical circuit simulation and the chronc animal experiments with the artificial heart system. As the results, an electrical circuit simulation showed chaotic dynamics according to the increase of the time lag in the baroreflex loop. Furthermore, an automatic control algorithm simulating the baroreflex system with an artificial heart system could generate the chaotic hemodynamics in the chronc animal experiments. These results suggest that Baroreflex system plays an important role when we consider the determitistic chaos in the hemodynamic parameters.

  153. Analyses of Transfer Characteristics between Blood Pressure and Heart Rate as Evaluation of Autonomic Nervous Function

    TANAKA Akira, YOSHIZAWA Makoto, ABE Ken-ichi, YAMBE Tomoyuki, NITTA Shin-ichi

    15 357-360 2000/10/13

  154. A Noninvasive Estimation Tool for Cardiac Function (E_<max> and PVA)

    YOSHIZAWA Makoto, HIKOSAKA Takahiro, TANAKA Akira, ABE Ken-ichi, SAIJO Yoshifumi, YAMBE Tomoyuki, NITTA Shin-ichi, KASS David A.

    15 189-192 2000/10/13

  155. Automatic Monitoring of an Artificial Heart Using a Double-Layered Self-Organizing Map

    WANG Xiao-Zheng, YOSHIZAWA Makoto, TANAKA Akira, ABE Ken-ichi, YAMBE Tomoyuki, NITTA Shin-ichi

    15 193-196 2000/10/13

  156. Noninvasive Estimation of Left Ventricular Pressure Waveform

    KAWAGISHI Takefumi, YOSHIZAWA Makoto, TANAKA Akira, ABE Ken-ichi, SAIJO Yosifumi, YAMBE Tomoyuki, NITTA Shin-ichi

    15 185-188 2000/10/13

  157. Fractal Dimension Analysis of R-R Interval by Using Holter ECG

    MATSUMOTO M., YAMBE T., TANAKA A., YOSHIZAWA M., NITTA S.

    30 (5) 239-242 2000/10/01

    ISSN:0286-7052

  158. Evaluation of 3D Images Based on Cross-Correlation between Blood Pressure and Heart Rate

    SUGITA Norihiro, YOSHIZAWA Makoto, TANAKA Akira, ABE Ken-ichi, YAMBE Tomoyuki, NITTA Shin-ichi

    Proceedings of the Virtual Reality Society of Japan,annual conference 5 435-438 2000/09/18

    Publisher: 日本バ-チャルリアリティ学会

    ISSN:1342-4564

  159. 高周波振動流が下半身血管インピーダンスへ与える影響

    許 立慶, 山家 智之, 西條 芳文

    加齢医学研究所雑誌 51 (3) 121-130 2000/07

    Publisher: 東北大学加齢医学研究所研究会

    ISSN:1340-3397

  160. Fractal dimension analysis of the RR interval recorded in Holter ECG

    YAMBE Tomoyuki, YOSHIZAWA Makoto, TANAKA Akira, NANKE Shunsuke, NITTA Shin-ichi

    20 S-1-10 2000/03/15

    ISSN:0285-1660

  161. 519 Development of an Artificial Sphincter Using Shape Memory Alloy

    NAKAMURA Hirokazu, TAKAGI Toshiyuki, LUO Yun, AMAE Shintaro, YANBE Tomoyuki, KAMIYAMA Takamichi, WADA Motoshi

    2000 (35) 194-195 2000/03/11

    Publisher: The Japan Society of Mechanical Engineers

    More details Close

    This paper describes a work on the development of an artificial sphincter actuator for the treatment of the functional disorder on bowel movement. The prototype acuator is composed of two shape memory alloy (SMA) plates with all-round shape memory effect (ARSME) ; the shapes of those plates are transformed from straight to arc in the heating process and reversed in the cooling process. This actuator is expected to work as a valve of a digestive canal. Its thermo-mechanical properties including the deformation and force generated during the phase transformation of SMA have been measured. The experiments on an living body show that this actuator has good self-bowel movement function.

  162. Automatic Detection of Abnormal Patterns and State Identification in Biomedical Signals using Hierarchical Self-Organizing Map

    WANG Xian-zheng, YOSHIZAWA Makoto, TANAKA Akira, ABE Ken-ichi, YAMBE Tomoyuki, NITTA Shin-ichi

    14 461-464 1999/10/06

  163. Vascular Resistance during Left Heart Bypass with the Implantable Vibrating Flow Pump Ventricular Assist System

    YAMBE Tomoyuki, KOBAYASHI Shin-ichi, NANKA Shunsuke

    14 (2) 153-158 1999/04/10

    ISSN:0914-8922

  164. Open-loop Analysis between Heart Rate and Blood Pressure using Artificial Heart

    TANAKA Akira, YOSHIZAWA Makoto, NOMURA Takashi, ABE Ken-ichi, YAMBE Tomoyuki, NITTA Shin-ichi, ABE Yusuke, CHINZEI Tsuneo, IMACHI Kou

    13 355-358 1998/09/09

  165. Effect of Ventricular Assistance on Left Ventricular Maximum Elastance E_<max>

    YOSHIZAWA Makoto, TANAKA Akira, ABE Ken-ichi, TAKEDA Hiroshi, KAKINUMA Yoshito, YAMBE Tomoyuki, NITTA Shin-ichi

    13 351-354 1998/09/09

  166. Studies on the variation of regional wall motion of the ischemic heart against time in the stress echocardiography

    OKAWAI H., NITTA K., TAKAHASHI K., KATAHIRA Y., SONOBE T., SHU L., TANAKA M., NITTA S., YAMBE T., OSAWA H.

    25 (4) 430-430 1998/04/15

    ISSN:1346-1176

  167. 36)左室収縮のゆらぎの研究

    小宮 仁, 山家 智之, 静 和彦, 野宮 琢磨, 浅海 泰栄, 仁田 新一, 吉澤 誠, 那須川 慎介

    Japanese circulation journal 61 790-790 1998/03/20

    Publisher: 社団法人日本循環器学会

    ISSN:0047-1828

  168. WEARABLE VENTRICULAR ASSIST DEVICE USING THE VIBRATING FLOW PUMP

    YAMBE Tomoyuki, HONGO Tadayoshi, KOBAYASHI Shin-ichi, OWADA Naoki, NANKA Shunsuke, TABAYASHI Kouichi, MATSUKI Hidetoshi, YOSHIZAWA Makoto, HASHIMOTO Hiroyuki, TAKEDA Hiroshi, NITTA Shin-ichi

    IEICE technical report. ME and bio cybernetics 97 (371) 83-88 1997/11/07

    Publisher: The Institute of Electronics, Information and Communication Engineers

    More details Close

    Aiming at a wearable type ventricular assist device (VAD), Vibrating flow pump (VFP) was developed in Tohoku University. The transcutaneous energy transmission system (TETS) using the amorphousness fiber was developed to constitute the totally implantable VAD system. Artificial heart works with high frequency compared with a natural heart of a biological system. It is frequency of 10-50 Hz. In this research, animal experiment was carried out with the healthy adult goats. Blood from apex of heart was received, and it was sent to aorta. Enough supporting effect of left heart was provided. In particular, depression effect of left ventricle was obvousness. As a result, enough artificial heart flow was provided. For the tottaly implantation type VAD, left heart bypass of almost 100 % may become necessary in some situations. So, apex approaches of the left heart bypass may be desirable. From the anatomical consideration,, an apex of a heart is suitable for the VFP of this totally implantation type. In the left heart bypass which apex of heart was used for, almost 100 % bypass was possible. It is the result which is important to develop it as artificial heart of totally implantable type, VFP was considered to be useful as totally implable type assistance artificial heart by this result.

  169. Explanation of the echo from the oblique surface from a standpoint of echography.

    OKAWAI H., SAIJO Y., YAMBE T., OSAWA H., SASAKI H., SHU L., NITTA K.

    24 (9) 358-358 1997/09/15

    ISSN:1346-1176

  170. Information entropy of the left ventricular contraction and its clinical significance

    YAMBE T., NANKA S., OKAWAI H., SAIJO Y., NITTA S.

    24 (9) 409-409 1997/09/15

    ISSN:1346-1176

  171. A Method of Estimating Left Ventricular Power

    YOSHIZAWA Makoto, ABE Ken-ichi, TAKEDA Hiroshi, KAKINUMA Yoshito, AKIHO Hiroshi, YAMBE Tomoyuki, NITTA Shin-ichi

    12 121-124 1997/09/04

  172. Nonlinear Dynamics of the Autonomic Nerve Discharges during Virtual Reality immersion

    YAMBE Tomoyuki, CHIBA Hiroshi, YOSHIZAWA Makoto, TANAKA Akira, SUGIYAMA Yoshiki, MANO Tadaaki, NITTA Shin-ichi

    12 149-152 1997/09/04

  173. Explanation of the echo from epicardium of posterior wall in the echocardiography

    OKAWAI H., NITTA S., YAMBE T., SAIJO Y., SASAKI H., SHU L.

    24 (3) 474-474 1997/03/15

    ISSN:1346-1176

  174. Sign of wall motion abnormality observed in the information of wall thickness and excursion in the stress echocardiography

    OKAWAI H., NITTA K., TAKAHASHI K., KATAHIRA Y., SONOBE T., YAMBE T., SHU L., TANAKA M., NITTA S.

    24 (3) 491-491 1997/03/15

    ISSN:1346-1176

  175. IS035 Development of the totally implantble ventricular assist system using Vibrating flow pump and Percutaneous transcutaneous energy transmission system with amorphous fibers

    Yambe T., Kobayashi S., Nanka S., Shizuka K., Nitta S., Matsuki H.

    Japanese circulation journal 61 27-27 1997/03/05

    Publisher: Japanese Circulation Society

    ISSN:0047-1828

  176. Fluctuations in Hemodynamic Parameters Left Ventricular Assistance

    YAMABE Tomoyuki, NANKA Shunsuke, UCHIDA Naoki, MIURA Makoto, YOSHIZAWA Makoto, TAKEDA Hiroshi, NITTA Shinichi

    33 (5) 459-463 1996/10/15

    ISSN:0288-9250

  177. 人工心臓の生理学

    山家 智之, 薗部 太郎, 仁田 新一, 吉澤 誠

    BME : bio medical engineering 10 (10) 60-69 1996/10/10

    ISSN:0913-7556

  178. 心拍変動の解析による左心補助人工心臓臨床応用時の自律神経機能評価

    山家 智之, 南家 俊介, 小林 信一, 永沼 滋, 秋保 洋, 仁田 新一, 茂泉 善政, 福寿 岳雄, 内田 直樹, 田林 晄一, 田中 明, 吉住 直彦, 阿部 健一, 吉澤 誠, 高安 秀樹

    心電図 = Electrocardiology 16 27-27 1996/03/31

    ISSN:0285-1660

  179. 27)冠動脈楔入圧の検討(第3報) : 慢性閉塞病変における検討(日本循環器学会第113回東北地方会)

    菊地 雄一, 目黒 泰一郎, 遠藤 閑夫, 大友 達志, 和田 有行, 南家 俊介, 寺沢 良夫, 武田 久尚, 高橋 和彦, 柿沼 義人, 井筒 憲司, 山家 智之, 西條 芳文, 永沼 徹, 小林 信一

    Japanese circulation journal 59 605-605 1995/06/20

    Publisher: 社団法人日本循環器学会

    ISSN:0047-1828

  180. 10)KSエントロピーの計測による左室収縮時系列曲線におけるカオス的ダイナミクスの検出(日本循環器学会第113回東北地方会)

    山家 智之, 仁田 新一, 高橋 和彦, 西條 芳文, 永沼 滋, 小林 信一, 柿沼 義人, 秋保 洋, 南家 俊介, 大沢 上, 永沼 徹, 田中 元直, 福寿 赳雄, 三浦 誠, 内田 直樹, 田林 晄一, 阿部 健一, 吉沢 誠, 高安 秀樹

    Japanese circulation journal 59 603-603 1995/06/20

    Publisher: 社団法人日本循環器学会

    ISSN:0047-1828

  181. 0272 補助人工心臓は交感神経活動の情報量エントロピーを低下させる

    山家 智之, 南家 俊介, 小林 信一, 西條 芳文, 仁田 新一

    Japanese circulation journal 59 111-111 1995/03/01

    Publisher: 社団法人日本循環器学会

    ISSN:0047-1828

  182. 左心補助人工心臓駆動下の交感神経活動に関する実験的研究

    山家 智之, 仁田 新一, 片平 美明, 薗部 太郎, 西条 芳文, 秋 保洋, 永沼 滋, 田中 元直

    Japanese circulation journal 56 1035-1035 1992/10/20

    Publisher: 社団法人日本循環器学会

    ISSN:0047-1828

  183. 巨細胞性心筋炎の1例 : 日本循環器学会第98回東北地方会

    西條 芳文, 山家 智之, 仁田 桂子, 目黒 泰一郎, 三友 紀男, 舟生 俊夫

    Japanese circulation journal 56 456-456 1992/05/20

    Publisher: 社団法人日本循環器学会

    ISSN:0047-1828

  184. 冠動脈高度狭窄病変の(非梗塞)短期進展例の検討 : 日本循環器学会第98回東北地方会

    山家 智之, 仁田 桂子, 西條 芳文, 目黒 泰一郎

    Japanese circulation journal 56 452-452 1992/05/20

    Publisher: 社団法人日本循環器学会

    ISSN:0047-1828

  185. 補助人工心臓駆動下の超音波像 特に流出インピーダンス変化による心機能回復度の推定について (日本超音波医学会研究発表会講演論文集)

    山家智之

    日本超音波医学会研究発表会講演論文集 51回 763-764 1987/10

Show all ︎Show first 5

Books and Other Publications 15

  1. Nano-Biomedical Engineering in the East Asian-Pacific Rim Region

    T.Yamaguchi, ed. Tomoyuki Yambe

    ISBN 2010/03

  2. 新世界成長拠点に築くナノ医工学拠点

    山口隆美, 山家智之

    ISSN 2010/03

  3. 医科学応用研究財団研究報告

    山田和生, d, 山家智之, 阿部裕輔, 松木英敏, 浅野英司, 圓山重直

    ライフメディコム 2008/02

  4. SICEcatalog08SY0001

    Y.Kinouchi, ed. T.Yambe, Y.Shiraishi, H.Liu, Y.Saijo, I.Saito, T.Isoyama, Y.Abe

    SICE 2008/01

  5. ヒューマンサイエンス&テクノロジー

    矢野雅文, 山家智之

    東北大学 2007/12/01

  6. Proceed 3rd Japan-Auttralia Cardiovas Bioeng Symposium

    Yambe T, Yoshizawa M, Tanaka A Abe, Km Kawano, S, Matsuki H, Maruyama S Amae, S Wada, M, Kamiyama, T, Takagi T Luo, Y, Hayashi J Nanka, S Saijo, Y, Mibiki Y, Shibata M, Nitta S

    NK Int Co 2001/04

  7. Heart replacement - Artificial Heart 6, Tokyo

    Yambe T Nanka, S Sonobe, T, Naganuma S Kobayashi, S, K.Shizuka, M.Watanabe, Tanaka, A, Yoshizawa M Abe, K Miura M Tabayashi, K, H.Takayasu, K.Gouhara, K.Naitoh, Takeda, H, Nitta S

    Springer-Verlag 1998/04

  8. Heart replacement - Artificial Heart 5, Tokyo

    Yambe T Nanka, S Sonobe, T, Naganuma Kobayashi S S

    Springer-Verlag 1995/04

  9. Artificial Heart 1993

    Yambe T Nitta, S Katahira Y Sonobe, T Naganuma, S, Y.KakinumTanaka, A, M Fukuju, T Miura M Mohri H, Yoshizawa M Koide S, Takeda H

    Artificial Heart 1993, Switzerland: Harwood Academic publishers 1993/04

  10. Artificial Heart 4

    Yambe T Nitta, S Katahira Y Sonobe, T, Naganuma, S Akiho, H, Hayashi H Tanaka, M, Miura M Sato, N Mohri, H, Yoshizawa M, Takeda H

    Tokyo: Springer-Verlag 1992/04

  11. Proceed 14th Ann Int Conf IEEE Eng in Med Biol Soc 2

    Yambe T Nitta, S Katahira Y Sonobe, T Naganuma, S, Y.Kakinuma, Akiho H, Sato, N Miura M Mohri H, Yoshizawa M Koide S, Takeda H

    IEEE 1992/04

  12. Artificial Organs14

    TYambe

    Blackwell 1991/04

  13. Artificial Heart 3.

    Yambe T Nitta, S Katahira Y Sonobe, T, Naganuma, S Akiho, H, Hayashi H Tanaka, M, Miura M Sato, N Mohri, H, Yoshizawa M, Takeda H

    Springer-Verlag, 1991/04

  14. Lekar a Technika

    Yambe T Nitta, S Katahira, Y, Tanaka M

    Lekar a Technika 1991/04

  15. New Trends in Autonomic Nervous System Research -Basic and Clinical Investigation. Amsterdam

    Yambe T Nitta, S Katahira Y Sonobe, T, Naganuma, S Akiho, H, Hayashi H Tanaka, M, Miura M Sato, N Mohri, H, Yoshizawa M, Takeda H

    Excerpta Medica, 1991/04

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Presentations 19

  1. 後天性von Willebrand病の血行力学的評価を目的とした流体剪断負荷試験装置の開発

    舘崎祐馬, 福澤奎人, 白石泰之, 井上雄介, 山田昭博, 早川正樹, 萱島道徳, 松本雅則, 堀内久徳, 山家智之

    第32回バイオエンジニアリング講演会 2019/12/20

  2. 微細管路系による流体剪断負荷とvon Willebrand factor損傷に関する特性評価の基礎検討

    舘崎祐馬, 白石泰之, 井上雄介, 山田昭博, 岩元直樹, 盛田良介, Ahmad Faiz Ibadurrahman, 橋本真登香, 早川正樹, 萱島道徳, 松本雅則, 堀内久徳, 山家智之

    第57回日本人工臓器学会大会 2019/11/15

  3. 機械的流体剪断負荷とVWF損傷に関する実験的検討

    舘崎祐馬, 白石泰之, 井上雄介, 山田昭博, 岩元直樹, 盛田良介, Ahmad Faiz Ibadurrahman, 橋本真登香, 早川正樹, 萱島道徳, 松本雅則, 堀内久徳, 山家智之

    2019/10/31

  4. Development of Evaluation System for Von Willebrand Factor Degradation by Mechanical Stress of Blood Pump

    Yusuke Inoue, Masaki Hayakawa, Akihiro Yamada, Masanori Matsumoto, Hisanori Horiuchi, Yasuyuki Shiraishi, Yuma Tachizaki, Genta Sahara, Aoi Nakahata, Naoki Iwamoto, Ryosuke Morita, Tomoyuki Yambe

    41th International Engineering in Medicine and Biology Conference 2019/07/24

  5. 微細管路を用いた血流特性が及ぼすvon Willebrand factor(VWF)への血行力学的影響の基礎検討

    舘崎祐馬, 白石泰之, 井上雄介, 山田昭博, 軽部雅人, 源田達也, 岩元直樹, 盛田良介, 早川正樹, 松本雅則, 堀内久徳, 山家智之

    第58回日本生体医工学会大会 2019/06/08

  6. VWFに注目した高せん断応力と出血に関する基礎研究

    井上雄介, 早川正樹, 松本雅則, 堀内久徳, 山田昭博, 白石泰之, 平恭紀, 荒川友哉, 弓場充, 軽部雅人, 源田達也, 山家智之

    第46回人工心臓と補助循環懇話会学術集会 2018/02/10

  7. 人工臓器医工学を実学として展開する

    山家智之

    第13界公益社団法人計測自動制御学会システムインテグレーション部門講演会 2012/12/20

  8. ストレスの循環機能への影響とその応用

    山家智之

    第2回ストレス計測技術応用策定調査委員会 2011/10/14

  9. 寸口脈の科学性

    山家智之

    第25回経絡治療学会 2010/03/27

  10. 脈波伝播速度CAVIの予防医学への応用

    山家智之

    宮城社会保険病院病診連携会 2010/02/26

  11. ストレスと自律神経

    山家智之

    平成21年度第3回心理負荷測定システム開発委員会 2010/02/10

  12. 脈波の診断の予防医学への応用

    山家智之

    栗原医師会特別講演会 2010/01/21

  13. 人工臓器の開発と東北大学の医工学

    山家智之

    第33回北斗会特別講演会 2009/11/10

  14. 人工内臓と高分子化学

    山家智之

    東レ東北大学共同研究会 2009/02/26

  15. CAVIと血圧反射機能

    山家智之

    愛媛大学HTP研究会 2009/02/02

  16. 運転実行機能と自律神経

    山家智之

    mobility & smart aging 2009/01/23

  17. 人工心臓と脈波の診断

    山家智之

    第49回仙南循環器懇話会 2008/11/18

  18. 無拍動人工心臓と脈波伝播速度

    山家智之

    第9回香川心臓病フォーラム 2008/08/08

  19. 脈診の温故知新

    山家智之

    日本東洋医学学会東北支部会 2007/07/08

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Research Projects 55

  1. Biomechanical Analysis for Mechanical Circulatory Support of the Fontan Circulation

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (B)

    Institution: Komatsu University

    2023/04/01 - 2027/03/31

  2. Platform design for von Willebrand factor response evaluation in circulatory support

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (B)

    Institution: Tohoku University

    2022/04/01 - 2027/03/31

  3. Inconvenient truth of autonomous driving--Automatic detection and prevention of driver's motion sickness

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (B)

    Institution: Tohoku University

    2020/04/01 - 2024/03/31

  4. 能動的精密表面温度計測を用いた熱パルスレーダ-による癌の生体内診断

    圓山 重直, 野中 崇, 井関 祐也, 細川 靖, 藤村 卓, 山家 智之, 岡部 孝裕, 古川 琢磨, 郭 福会, 横田 実世

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 基盤研究(B)

    Institution: 八戸工業高等専門学校

    2020/04/01 - 2023/03/31

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    本研究の目的は,これまで研究してきたガードヒータ型高精度表面温度計測をさらに発展させ,半導体薄膜サーミスタを用いた皮膚癌や内視鏡手術用カテーテル熱パルスレーダーを開発し,癌の生体内診断を行う新たな診断法を確立することである.さらに動物実験や,模擬生体で皮膚や臓器内部の熱的性質を計測し,手術や診断の精度を格段に向上させる.つまり,(1)薄膜サーミスタと小型ペルチェモジュールを組み合わせた高精度能動温度プローブのプロトタイプを製作し,ダブル熱パルスレーダーの基本動作を模擬生体で実験する.(2)皮膚ガンや臓器ガンが,リンパ血流などの物質移動が大きいことを考慮した新しい生体伝熱モデルの構築を行い,熱パルスレーダーの臨床結果を記述する新理論を展開する.(3)さらに小型のサーミスタ・プローブと小型ペルチェ冷却機構を製作し,内視鏡に組み込んで消化器や腹腔内手術の新しい診断方法としてのカテーテル型熱パルスレーダーを開発し,模擬生体と動物実験でその有用性を実証する. 前年度までに(1)の高精度能動温度プローブのプロトタイプの製作が完了したため,2年目にあたる令和3年度には開発した高精度能動温度プローブを用いた実験的検討および数値的検討を行った.具体的には皮膚構造を模擬したファントムによる実験的検討および数値シミュレーションによる検討から,皮膚癌の早期診断の可能性を明らかにした.また,小型ペルチェ冷却機構を具備する新型プローブの開発を行い,基本的性能評価実験を開始した.さらに,本研究の要となる,複数のサーミスタをmKオーダーで温度検定可能な固体型温度校正装置の開発および熱的評価実験を実施し本装置の有用性を確認した.

  5. Early diagnosis and low invasive treatment of cancer by micro/nano thermal engineering

    Maruyama Shigenao

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (B)

    2016/04/01 - 2020/03/31

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    This study measured the effective thermal conductivity of healthy and lesional skin in 11 cancer patients. Clinical studies have shown that when the tumor invades the dermis, the effective thermal conductivity of the lesion is higher than in the healthy area. Complex in-vivo heat transfer analysis during laser treatment was performed considering multiple heat scattering in vivo, plasmon heating by GNR, and combined heat transfer analysis considering blood flow and metabolic heat in the body. As a result, it was found that the GNR can be locally heated with a short irradiation time. We examined the usefulness of low invasive laser treatment by an experimental method. From the experiment, the usefulness of the surface cooling by the Peltier device could be evaluated.

  6. Development of an next generation elector-mechanical artificial heart system integrating tissue engineering technology

    Okamoto Eiji, Mitamura Yoshinori, Yambe Tomoyuki, Yano Tetsuya

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (C)

    Institution: Tokai University

    2016/04/01 - 2019/03/31

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    A left ventricular assist device connected with left ventricle in series can support circulation with pulsatile flow generated by left ventricle even if the motor speed increase. We developed a new device: a rear-impeller axial flow blood pump whose motor is installed in left ventricle and its impeller is placed at aortic valve position. The pump is small enough to install in left ventricle and the in-vitro results show it has enough pump performance to support cardiac function. Also we have investigated application of titanium mesh to an artificial heart system. The titanium mesh is an only metal scaffold that has strong stiffness and electrical conductivity. We have developed a transcutaneous communication system(TCS) using intra-body communication, and we developed a tissue-induced electrode using titanium mesh for applying communication current into a body. The animal experiments show that the titanium mesh electrode has enough electrical and tissue-induce performance for the TCS.

  7. R&amp;D of an axial flow blood pump for pediatric/partial assist use

    Yamane Takashi, MURAKAMI Arata, GOJO Satoshi, NISHIDA Masahiro, KOSAKA Ryo

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (C)

    Institution: Kobe University

    2015/04/01 - 2018/03/31

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    The research goal was pediatric/partial assist pumps without hemolysis or thrombosis at low flow, whose blood contacting surfaces were made of polymer. Partial assist pumps, KAP5-KAP8, were manufactured and evaluated. KAP6 improved the stall at low flow. KAP7 improved hemolytic property and can be used clinically up to 9000 rpm (100mmHg). Animal experiments for KAP6 and KAP7 clarified that the antithrombogenicity is not complete even at ACT>200s. Pediatric pumps, KPAP1-KPAP4, 130g in weight, 8ml in priming volume, and 27mm in outer diameter, were manufactured and evaluated. Though KPAP4 attained the necessary pump performance and hemolytic property, the antithrombogenicity was found to be incomplete.

  8. Parients' Self-contorol hypertension therapeutic devise

    Yambe Tomoyuki

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (B)

    Institution: Tohoku University

    2013/04/01 - 2018/03/31

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    The aim of this invention is the development of the totally implantable hypertension control machine, which will be able to be used by the patients themselves. For that purpose, hypertension control machine was composed with the implantable renal nerve cooling device using Peltier elements, the secondary coil with control system, and the first coil placed outside of the human body. The results of our study showed the sucessful invention of the renal nerve control system.

  9. Modelling of peripheral perfusion during mechanical circulatory system support

    Shiraishi Yasuyuki, MIURA HIDEKAZU, YAMBE TOMOYUKI, SASAKI KAZUMASU, AKIYAMA MASATOSHI, SAIKI YOSHIKATSU

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Challenging Exploratory Research

    Institution: Tohoku University

    2014/04/01 - 2016/03/31

    More details Close

    There is an increasing number of domiciliary treatment cases of patients with severe heart failure. However, it is anticipated that the deterioration of peripheral organs might be caused by the long-term rotary blood pump support. We focused on the development of a new diagnostic method for the evaluation of peripheral perfusion using a simple non-invasive imaging. By the method designed, the colour level of intensity showed blood flow perfusion which could be validated in goats’ experiments with the laser Doppler flow velocimetry. Secondly, we examined the effect of mechanical circulatory assistance ratio on peripheral perfusion by the changes in revolution numbers during the left ventricular support using a centrifugal blood pump that was connected from the apex to the descending aorta. As a result, it was indicated the system designed in the study could be useful for the evaluation of peripheral circulatory condition during mechanical circulatory support.

  10. Total Artificial Heart using Anatomically Compatible Helical Inflow Centrifugal Blood Pumps

    Miura Hidekazu, SHIRAISHI Yasuyuki, YAMBE Tomoyuki

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Young Scientists (B)

    Institution: Tohoku University

    2013/04/01 - 2016/03/31

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    In an acute animal experiment, the total artificial circulation model was made using the centrifugal type after marketing ,left ventricular assist devices, the regular way, an achieved possibility of the centrifugal type blood pump total artificial heart was indicated. An atrium pulse was kept in the total artificial heart animal experiment model, and we found that physiological control by automatic nerves system control might be achieved. A concept model of the total artificial heart was made using a three-dimensional printer and fitting study was performed in adult goats of sacrifice after the other experiments. The independent left and right blood pumps type total artificial heart concept of was indicated by miniaturizing the blood pumps. It was low in cost and a small embroidered design in one constraint ball bearing aiming longer durability was contrived and the movement was confirmed in a prototype pump.

  11. Arrythmia control device controlled by the patients

    Yambe Tomoyuki, SHIRAISHI YASUYUKI, MYURA HIDEKAZU, YOSHIZAWA MAKOTO

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Challenging Exploratory Research

    Institution: Tohoku University

    2013/04/01 - 2016/03/31

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    The aim of this study is the development of the totally implantable arrythmia control device, which will be controlles by the patients. In the Sendai quake, a lot of patients had arrhtmia and cardiovascular events. If we have arrthmia control device, it will good news for the patients. Arrthysmia control device was invented in this grants and patent was offered to the patent office.

  12. Impact of sinus Valsalva formation in valved conduits on prosthetic valve function placed in low pressure circulatory system; an ex-vivo comparative study

    SAI Sadahiro, SAIKI Yoshikatsu, MOTOYOSHI Naotaka, AKIYAMA Masatoshi, YAMBE Tomoyuki, SHIRAISHI Yasuyuki

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (C)

    Institution: Tohoku University

    2013/04/01 - 2016/03/31

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    The aim of this study is to elucidate a role of sinus Valsalva in a low pressure circulatory system by comparing hemodynamic performance of tested prosthetic valves in a composite graft with or without sinus formation. Composite grafts consisted of Dacron grafts with or without sinus formation incorporated with commercially available prosthetic valves (one type of mechanical valves and 2 bioprosthetic valves) were prepared. Mock circulation was constructed so as to replicate the low pressure circulatory system. Vortex flow was observed by an overhang part corresponding to a Valsalva sinus by echodynamography in all valves. When the sinus was present, decreased energy loss was obtained and the opening performance of valve was improved in one of the bioprosthetic valves. However regurgitant flow was increased by the presence of the sinus in all valves. It is further necessary to evaluate the movement of leaflet in order to investigate these phenomena.

  13. Development of an innovative elector-mechanical artificial organ

    Okamoto Eiji, MITAMURA YOSHINORI, YAMBE TOMOYUKI

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (C)

    Institution: Tokai University

    2013/04/01 - 2016/03/31

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    We have developed a new axial flow ventricular assist device that uses organs and tissues as composing elements, and it connects in series with natural heart. We also developed a tissue induced electrode using titanium mesh for the internal communication unit of the new transcutaneous information system using human body as conductive medium. We evaluated them in the animal experiments using goats, and we obtained enough performance to be promising a nest generation a ventricular assist system.

  14. Mechanical circulatory support system development platform for congenital heart diseases using a small implantable actuator

    Shiraishi Yasuyuki, MIURA HIDEKAZU, YAMBE TOMOYUKI, SASAKI KAZUMASU, YAMAGISHI MASAAKI, AKIYAMA MASATOSHI, SAIKI YOSHIKATSU

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (B)

    Institution: Tohoku University

    2013/04/01 - 2016/03/31

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    Long-term mechanical support systems development resources are needed for the surgical treatment of congenital heart failure. We employed a small-sized nano-tech Ni-Ti shape memory alloy fibre as an implantable actuator for the mechanical circulatory support. We focused on the development of two types of implantable devices; a) a right ventricular external contraction support belt, and b) a Fontan circulation active support system that could be used with the total cavopulmonary connection. We examined the systems function in the originally designed mock circulatory system with a silicone-rubber right ventricular model as well as in the animal models. As a result of this study, it was indicated that the micro actuation system for congenital heart failure support could be useful to exhibit the hemodynamic effect for the totally implantable system design.

  15. Risk Determination of Artificial Stereoscopic Vision Based on Searching for Onset Condition of 3D Sickness

    Yoshizawa Makoto, HOMMA Noriyasu, SUGITA Norihiro, YAMBE Tomoyuki, TANAKA Akira

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (B)

    Institution: Tohoku University

    2012/04/01 - 2016/03/31

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    Three dimensional visualization in movies, televisions and video games has been advancing rapidly. However, physiological and psychological effects of artificial stereoscopic vision on humans have not sufficiently been clarified. This study aimed at elucidation of the onset condition of so-called 3D sickness which is caused by artificial stereoscopic vision and the relationship between 3D sickness and visual fatigues. The experimental results have shown the followings: 1) Physiological indices for evaluation of 3D sickness may include psychological disturbance but it can be suppressed by adaptation. 2) It is possible that the cause of visual fatigue in stereoscopic vision can be explained using the contradiction between convergence and accommodation mechanisms. 3) Vertical disparity caused by the tilt of the head should be less than about 0.6 degree to avoid 3D sickness.

  16. Verification of role-sharing hypothesis of circulatory control and its application to health monitoring using sensors for video games

    YOSHIZAWA Makoto, HOMMA Noriyasu, SUGITA Norihiro, YAMBE Tomoyuki, TANAKA Akira

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Challenging Exploratory Research

    Institution: Tohoku University

    2012/04/01 - 2015/03/31

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    This study aimed at developing an estimation system of the baroreflex function, which can be used in daily life using the photoplethysmogram based on dynamics between blood pressure and heart rate. First, it was revealed that two indices, i.e., CVRR defined as the standard deviation of heart rate normalized by its mean value and μPA defined as the natural logarithm of the ratio of low frequency components to high frequency components of the pulse wave amplitude, have high discrimination ability and high reproducibility. Secondly, it was shown that a subject’s age can be estimated with these two indices with the correlation coefficient of 0.774. Finally, it was suggested that the baroreflex function can be estimated by processing the video images of a human body taken with an ordinary video camera.

  17. Development of implantable artificial myocardial assist device for right ventricular support

    MASUDA SHINYA, SHIBUYA Takumi, KAWAMOTO Shunsuke, SAIKI Yoshikatsu, YANBE Tomoyuki, AKIYAMA Masatoshi

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (C)

    Institution: Tohoku University

    2012/04/01 - 2015/03/31

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    We confirmed a supporting effect in Mock circuit and decided a structure of the device and made a canine right heart failure model by injected ethanol to a free wall of right ventricle. After 2 weeks on injection ethanol, in a canine model, RVSW reduced and a pathological liver congestion was revealed. We carried out an acute experiment for a right heart failure model with a device of artificial myocardium. The device of artificial myocardium led the increase of left ventricular end-diastolic volume. We would improve this device and perform the chronic experiment for effectiveness.

  18. The evaluation method for the effect of the various unnatural video components on viewers using physiological indices.

    TANAKA Akira, YOSHIZAWA Makoto, SUGITA Norihiro, YAMBE Tomoyuki

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (C)

    Institution: Fukushima University

    2011 - 2013

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    The aim of this study was to develop the evaluation method for the effect of the various unnatural video components such as excessive motion on viewers. In order to achieve this object, a new physiological index of autonomic nerve activity relating to vascular regulation was proposed. The model which represents the relationship between video motion and a degree of discomfort was also proposed using non-linear Hammerstein model, in which the discomfort level was estimated by using a multiple regression model whose explanatory variables ware several physiological indices including the proposed vascular index. The model could explain the change in a degree of discomfort with a correlation coefficient of 0.74. It seems that these results can contribute to an objective assessment of visual image safety.

  19. Development of an artificial papillary muscle recovering left ventricular functions

    SHIRAISHI Yasuyuki, YAMBE Tomoyuki, MIURA Hidekazu, UMEZU Mitsuo, HOMMA Dai

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Challenging Exploratory Research

    Institution: Tohoku University

    2011 - 2012

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    We developed an artificial papillary muscle by using covalent-type Ni-Ti anisotropic shape memory fibres. We could achieve the development of a tissue-rubber hybrid left ventricular model including native heart valves. Subsequently we could investigate optimised mechanical interactions between mitral valve leaflets and the left ventricle with the artificial papillary muscle reducing mitral valve regurgitation.

  20. Development of an artificial myocardial assist system for paediatric heart diseases

    SHIRAISHI Yasuyuki, YAMBE Tomoyuki, YAMAGISHI Masaaki, MORITA Kiyozo, HOMMA DAI

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Young Scientists (A)

    Institution: Tohoku University

    2010 - 2012

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    We have developed paediatric myocardial and circulatory assist systems as an alternative surgical treatment for congenital heart diseases. A covalent-type anisotropic Ni-Ti alloy fibre was employed as the actuator for the totally-implantable circulatory assist system which could be clinically applied for small sized patients. Subsequently, the two types of assisted circulation system, a) a contractile extra cardiac conduit for Fontan procedures, and b) a ventricular pouch support system were implemented based on the hemodynamic and thermodynamic control.

  21. The possibility of artificial myocardial assist system to support failed heart model.

    AKIYAMA Masatoshi, YANBE Tomoyuki, SHIBUYA Takumi

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (C)

    Institution: Tohoku University

    2010 - 2012

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    According to the results of our previous study, which was the hemodynamic support by artificial myocardium to the normal heart, the artificial myocardium was applied to the canine heart failure model induced by rapid ventricular pacing. However, its effect was not enough to improve hemodynamic parameters. The cause was suspected that the geometry of normal heart and failed heart was different. The wrapping pattern of artificial myocardium was studied using Mock circulation with the spherical sack, and the ideal pattern for failed heart was confirmed. We performed acute study using canine heart failure model again. The hemodynamic data was collected using the conductance catheter and echocardiography. The artificial myocardium led the increase of Emax value and the decrease of functional mitral regurgitation volume. These results support that the artificial myocardium could be the alternative therapy of advanced heart failure. In future, chronic evaluation of artificial myocardium is necessary for its effectiveness, durability, and safety.

  22. Study of electronics technology using a human body as electronics parts for development of an innovative electro-mechanical artificial organ

    OKAMOTO Eiji, MITAMURA Yoshinori, YAMBE Tomoyuki

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (C)

    Institution: Tokai University

    2010 - 2012

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    In this study, we developed a new transcutaneous communication system that uses the human body as a conductive medium for monitoring and controlling artificial hearts and other artificial organs in the body. Performance of the TCS was evaluated by a communication test in an animal experiment using a goat. The TCS was able to transmit data concurrently for 4 weeks between everywhere on the surface of the body and everywhere inside the body under full duplex communication. The newly developed TCS has promise as to be a next-generation transcutaneous communication device.

  23. 新たな自律神経情報解析法と薬効評価モデルの開発研究

    劉 紅箭, 山家 智之, 白石 泰之, 三浦 英和

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 挑戦的萌芽研究

    Institution: 東北大学

    2011 - 2011

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    自律神経系活動の情報を得るために、現在心拍のパワースペクトル解析法による非侵襲的な測定方法がよく利用されている。この解析方法によって、高周波数および低周波数成分の変化に基づいて、交感神経と副交感神経の総合的な活動を評価することができる。低周波成分を示す交感神経活動にはβ受容体交感神経活動とα受容体交感神経活動などが含まれるため、従来の方法では複雑な合成波を解釈していたことになる。したがって、これらの受容体の種類に特異的な周波数スペクトルを同定することにより、個々の受容体の活動を非侵襲的に計測することが可能になる。種々の循環器疾患に対して、その発病のメカニズムの研究と自律神経のシグナル伝達経路の情報、治療方案の選択と治療効果の評価、病気の予防と予後、遺伝子多型の研究および新薬の開発が大きく期待され、複合波の分離ができることにより正確な情報量を見出せる新しい解析法の開発は不可欠である。 循環系信号の周期と非周期変化の受容体交感神経活動のメカニズムを明らかにするために、健常成山羊を用いて塩酸メキサン静注により、心電図及び大動脈圧波形は、デジタルレコーダによって1kHzのサンプリング周波数で同時記録した。RR間隔及び大動脈圧変動は、3次スプライン関数を用いて補間し再サンプリングを行い、それぞれ周波数解析を行った。周波数解析によって0.15-0.40Hzの高周波成分(HF)及び0.04-0.15Hzの低周波数成分(LF)を主成分とする要素に分解した。メキサン投与10分後の心拍数と大動脈圧のLF、HFおよびLF/HF変化から、交感神経-副交感神経の制御バランスが変動し、循環動態に対する外乱への積極的な応答が有意に認められた。また、薬物負荷による血管抵抗変化に対する心拍応答特性にも示された。心拍変動と動脈圧、圧受容体および循環中枢が相互に複雑なフィードバックループを形成しており、これが一種の複雑系として考えられる。

  24. リアクティブ心臓モデリングによる心不全メカニクスの徹底解明

    白石 泰之, 山家 智之

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 挑戦的萌芽研究

    Institution: 東北大学

    2008 - 2009

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    心室形成術や、補助循環施行時に経験的には説明のしづらい心不全病態生理の変化が起こる。これらに対して、本研究は、微細形状記憶合金線維を利用して人工心筋開発技術を基盤として、3次元のリアクティブ挙動が可能な心臓モデルを開発し、科学的データを提示することを目的とする。本研究で開発に挑戦する装置は、超小型のマイクロマシン化した機械式アクチュエータを集積し、心臓の病態を3次元検査データに基づいて精密に再現し、さらに拍動を伴って心不全のメカニクスを動的に提示するものである。このシステムは、生体心臓のMRIデータに基づいて迅速にローコストで術前の形態を機械的に再構築し、心筋の解剖学的構造を模擬した駆動メカニズムを組み込むことで、循環生理学的知見に基づくロボット工学を応用した制御を行い、外部からの形成による変形にリアクティブに対応する。本年度は、とくに病態モデルのメカニクス解析とそのその結果を昨年度までに構築した機械的モデルへの融合を試み、リアクティブ心臓モデルの基本構造設計および作成法の検討を進めた。結果として、(a)動物実験による心臓解剖学的構造及び心筋走向の数値的再構築、(b)人工心筋の基盤技術を応用した可観測の収縮アクチュエータの開発、(c)外科治療の直前術前評価を可能とする解析情報融合化タンジブルモデルを具現化した。臨床ニーズと対照させ、患者個々の心不全病態に対して客観的かつ定量的な心筋メカニクス解析結果を重畳したシステムの利用が可能となった。

  25. Development of a passive-active artificialmyocardium reconcilingthe physiological demands with hemodynamic changes

    SHIRAISHI Yasuyuki, YAMBE Tomoyuki, SAIJO Yoshifumi, UMEZU Mitsuo, FUJIMOTO Tetsuo, BABA Atsushi, TABAYASHI Koichi, HOMMA Dai

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Young Scientists (A)

    Institution: Tohoku University

    2007 - 2009

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    We developed a sophisticated artificial myocardium which consisted of shape memory alloy fibre units. We applied the PID method for the control of myocardial assist, and examined the dynamic performance as well as hemodynamic changes in goats. It was anticipated that the passive-active artificial myocardium control could be achieved which was reconciling the physiological demands with pathophysiological diagnosis by using our new methodology.

  26. 患者自身で発作をコントロールできる完全埋込型てんかん発作制御装置の開発

    山家 智之, 圓山 重直, 白石 泰之, 佐藤 文博

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 挑戦的萌芽研究

    Institution: 東北大学

    2007 - 2009

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    本研究計画の目的は、全世界の人口の0.5~1.5%(約六千万人前後)の有病率を持つと報告される全人類にとっても最も重要な疾患の一つである「てんかん」の発作を、患者が自分で発作をコントロールすることができる全く新しい人工内臓「完全埋込型てんかん発作停止装置」の開発である。そのために、外科的な病巣切除とは根本的に異なる安全な治療方法としてのナノテク経皮伝送技術などを応用したてんかん発作停止装置の発明に至り、東北大学、ミシガン大学などと協同で、既に特許申請も行った(特願2005-291008)。システムは、ペルチェ素子等の電子冷却素子等を応用した体内冷却部とヒートシンクでナノレベル最適熱設計を行ったてんかん停止装置本体、装置にエネルギーを供給する経皮エネルギー伝送システム、及びナノDLCセンサ等を用いたコントローラとしてのてんかん発作診断装置より構成される。最適熱設計により病巣の最適の冷却を行うことができ、電子冷却素子では必ず問題となる反対側の熱の発生も、経皮エネルギー伝送システムを兼ねた対側のヒートシンクの最適熱設計によって完全に予防できる極めて安全性が高いシステムである。 試作したシステムは、体外の一次コイル及び電源ユニット、皮下にペースメーカのように埋め込まれる二次コイルを兼ねた精密な熱設計計算を行って熱放散を最小に最適化したヒートシンク、及びてんかんの焦点である病巣を冷却するペルチェ素子などを応用した電子冷却素子デバイスから構成され、冷却素子デバイスは、小切開を介して頭蓋内に一部挿入され、病巣を冷却する。ヒートシンクを兼ねた二次コイルは、頭蓋骨外でペースメーカのように皮下に置かれる。この方法論に採用により、最小限の侵襲でデバイスの埋め込みが可能になる。更に、デバイスは頭蓋骨に固定されるので、脳組織を傷害させる危険は極めて少ない安全性の高いものとなった。

  27. Study of Pulsatile Artificial Heart With no Compliance Chamber Drive by means of Method Mimicking Evolution of Life

    OKAMOTO Eiji, YANBE Tomoyuki, MITAMURA Yoshinori

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (C)

    2007 - 2009

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    We have studied a compliance chamber built in a inflow cannula of a pulsatile blood pump for reduction of space occupied by the compliance chamber. We also have developed magnetically suspended non-contact cam system to convert from rotational motion of a motor into rectilinear motion of pusher-plate to drive a total artificial heart. We confirmed performance of them in in-vitro experiments. While further studies are required to use our studies clinically, our study contributes to overcome drawback of a pulsatile artificial heart, and to develop a new small pulsatile artificial heart having life over 5 years like a non-pulsatile artificial heart.

  28. Comprehensive basic study on optimum flow condition of total artificial heart from the view point of microcirculation

    IMACHI Kou, YANBE Tomoyuki, SHIRAISHI Yasuyuki, ABE Yusuke, ISOYAMA Takashi, SAITO Itsuro, BABA Atsushi, TAKIURA Kouki, MOCHIZUKI Shuichi, VASKU Jaromir, DOBSAK Petr, KOUNO Akimasa, ONO Toshiya, INOUE Yausuke

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (A)

    Institution: Tohoku University

    2006 - 2009

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    It was succeeded to develop the following research tools to clarify the influences of flow dynamic states of total artificial heart such as pulsatile flow, continuous flow, etc. on microcirculation of the living body ; 1) Undulation pump total artificial heart that was enough compact to be implanted into the chest cavity of a goat weighing 40Kg and could generate any style of flow waveform, was developed. 2) A microcirculation probe that could be implanted into the body and observe continuously the microcirculation in the peripheral system without a microscope was developed. 3) These systems were implanted into goats chronically. The longest implantation period was 153 days and the difference between pulsatile and continuous flow on the living body including microcirculation was analysed during this period.

  29. Clinical evaluation of a noninvasive estimation system for cardiac function

    YOSHIZAWA Makoto, NITTA Shinichi, YAMBE Tomoyuki, SAIJO Yoshifumi, TANAKA Akira, SHIRAISHI Yasuyuki

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (B)

    Institution: Tohoku University

    2006 - 2008

  30. Innovation of Biomedical Engineering by Heat Transfer Control-Challenge to the Quality of Life-

    MARUYAMA Shigenao, YAMBE Tomoyuki, AIBA Setsuya, TOMINAGA Teiji, KOMIYA Atsuki

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (A)

    Institution: Tohoku University

    2006 - 2008

  31. 傾斜スケール磁気粒子流体の生体適合化による先進医工学への新展開

    西山 秀哉, 山家 智之, 西條 芳文, 高奈 秀匡

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 萌芽研究

    Institution: 東北大学

    2006 - 2007

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    工業用バルブや医療用シール等のMR流体流動システム設計のための基礎資料を提供することを目的として、磁場下にある最新の商用MR流体の詳細なレオロジー特性とオリジナルな可視化実験、圧力流れ場における矩形流路内流動構造の経時変化の実験解析、さらには、矩形流路内流量遮断特性から磁気機能性および流動制御特性を明らかにした。その結果、以下の結論を得た。 1.MR流体の流動曲線や降伏応力の再現性を確認するために、回転粘度計のMR流体試料と接触する回転スピンドルの頂角、円板ギャップ表面粗さによるレオロジー特性への影響を詳細に明らかにした。静的な降伏応力はずり速度が小さい場合、表面粗さがあると滑面に比して大きく、強磁場下でせん断力は平板ギャップが大きいと増加する。これは、棒状クラスター端面と回転スピンドル表面との摩擦力やすべりが影響していると考えられる。 2.圧力流れ場における流路内MR流体シールを破壊するためのピストン移動速度を0.5〜5mm/sに大きく変化させるために、平成18年度に製作したMRシールシステムを試作改良した。 3.磁場下でピストン駆動速度を変化させた場合のMR流体流路の最上流部、シール下端部の圧力の経時変化により、シール形成による流動遮断、シール崩壊および流動、さらには、シール再形成のシナリオをリアルタイムで明らかにした。いずれのピストン駆動速度においても、印加磁場強度の増加と共にシール耐圧が増加し、その増加率は印加磁場強度の二乗にほぼ比例する。また、ピストン駆動速度の増加に対しても、シール耐圧は著しく増加する。これは、ピストン駆動速度の増加に伴い、磁場作用近傍のシール上流部で強磁性微粒子密度が局所的に増加することにより、より強固なクラスターが形成されたためと考えられる。

  32. Development of fundamental method for research on the action mechanism of acupuncture and herbal medicine

    SEKI Takashi, YOSHIZAWA Makoto, YAMBE Tomoyuki, NITTA Shinichi, KONNO Satoshi

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (C)

    Institution: Tohoku University

    2006 - 2007

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    Acupuncture and herbal medicine might cause physiological, psychologic change in human body. This change may affects autonomic nervous system. We define p max as the maximum value of the cross-correlation coefficient between two variables (blood pressure or pulse wave transmission time, cardiac rate), and we think that this index can reflect the subject's physiological and emotional state. Beat-to-beat data of heart rate and Pulse Transition Time (PTT) were interpolated by a cubic spline function. After that, the data were filtered through a band-pass filter between 0.08 and 0.1 Hz in order to extract the Mayer wave components. At each second, the maximum cross-correlation coefficient from PTT to HR was calculated time-discretely on the basis of 2 minutes data segmented by a Hamming window. The window was shifted every 1 second. Thus, changes in P (rho) max with time were obtained. 17 healthy volunteers (7 men, 10 women, and average age 27 years old) were recruited and seal needle was admitted to the acupoint Taixi. By using placebo seal needle, we could conducted a double-blind randomized controlled study. Only P max (PTT-HR) changed significantly in real seal needle insertion. 5 healthy volunteers (4 men, 1 women, and average age 29 years old) were recruited and water and herbal medicines (Kami-syouyou San, Ouren-gedoku To) were administered. And only P max (BP-HR) changed significantly in administration with Kami-syouyou San. These result indicate that the P max may be a suitable index for research of acupucture and herbal medicine.

  33. autonomous distributed control system for totally implantable assist pump sisytem

    OKAMOTO Eiji, MITAMURA Yoshinori, YOSHHIZAWA Makoto, YAMBE Tomoyuki

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (C)

    Institution: Hokkaido Tokai University

    2004 - 2006

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    Basic study for realization of adaptation, evolution, and self-diagnosis on an artificial heart has been carried out by an autonomous distributed control system for an ultra-lightweight pulsatile VAD (volume of 285 ml and weight of 360 g). The autonomous distributed control system was built by 4 layers (input layer, measurement layer, control layer, output layer) and an object manager, which was realized on a lchip microcomputer (Hitachi, SH7044, Japan). The control layer consists of 3 autonomous objects: position control, velocity control, and current control. The position and velocity control objects are constructed by fuzzy inference algorism in order to build doctors' and engineers' knowledge into the VAD control. The object manager paces events on each object in order to maintain time series processes. In vitro experiments showed that The VAD has maximum pump outflow of 5.1 L/min against afterload of 100 mmHg under control of our autonomous control system. The self-diagnosis has been realized by a neural network based early diagnosis system using artificial heart sound. A long-term animal experiment showed that the early diagnosis system automatically and successfully had detected malfunction of pump 24 hours before pump stoppage. The above results show that our VAD system promises possibility as a new superior artificial heart system.

  34. 非平衡熱電素子を用いた医療用急速冷却伝熱制御の研究

    圓山 重直, 山家 智乏, 小宮 敦樹

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 萌芽研究

    Institution: 東北大学

    2004 - 2005

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    本年度は,昨年度製作したクライオプローブを用いて実験的解析的研究を遂行し,凍結手術の際の効率的な冷却手法についての検討を行った.また昨年度の検証実験で明らかとなった,連続運転による最下点到達温度が長時間維持できないという問題点の克服のため,クライオプローブ先端部の構造を見直し,新たな先端部設計のクライオプローブの製作も行った. 圓山代表者により生体冷凍治療クライオプローブ先端部の再設計が行われ,先端部の熱が効率的に冷媒側に輸送されるデザインとし,高熱流束冷却伝熱制御を可能とした.新たに製作されたクライオプローブの性能評価は,小宮分担者による生体を擬似した寒天を用いた実験で行われた.これにより,新設計のクライオプローブでは長時間運転による最低到達点温度の上昇は認められず,昨年度製作したプロトタイプの問題点を克服できたと位置づけることができる. また,凍結手術の際の効率的な冷却方法についても解析的・実験的に検証を行った.解析的には生体伝熱方程式を用いて高精度数値シミュレーションを行い,表皮深部の真皮層の過渡冷却現象を視覚的に理解し,そこから高効率冷却法を検討した.また実験的には,モルモットの背皮を用いた動物実験を行い,数値シミュレーションを用いて検討した冷却方法での過渡冷却現象を観察した.これらの実験より,目標としている細胞を高効率に壊死させるには,急速冷却の他に繰り返し冷却法を施すことで達成できることが明らかとなった. これらの研究成果は,別紙に示すごとく国内外の学術講演会にて発表を行っており,熱工学の分野にとどまらず医学分野においても高い評価を得ている.

  35. Development and Implementation of Control Strategy for Artificial Hearts from the Aspect of Complex Systems and Artificial Life

    ABE Ken-ichi, NITTA Shin-ichi, MATSUKI Hidetoshi, YOSHIZAWA Makoto, YAMBE Tomoyuki, HOMMA Tsuneyasu

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (B)

    2003 - 2005

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    Strictly speaking, the cardiovascular system is a complex system with large-scale, multivariate, nonlinear and nonstationary characteristics. The purpose of this study was to develop control strategies for artificial hearts in consideration of the characteristics of the cardiovascular system regarded as a living system. The fruits yielded by this study are shown below. First, we proposed a nonlinear model to simulate time trajectories of stroke volume and blood pressure by introducing a feedback effect reflecting autonomic nervous information based on heart rate variability. This model can generate a chaotic heart rate variability whose characteristic differs between rest and exercise conditions. The model seems to be adequate because responses of heart rate variability similar to the above one were found in a healthy human subject. Secondly, we discussed whether the cardiac function of the natural heart can be estimated even in a complex system such as a circulatory system assisted by a ventricular assist device (VAD) using continuous-flow pump in which the VAD and the natural heart are competing against each other. The results obtained from animal experiments showed that an index Emax could be estimated to some extent in such a complex situation. It was also suggested that a dynamic model based on differential equation should be considered for analysis rather than a static model even if a continuous-flow VAD is used because beating components caused by the natural heart cannot be ignored. Thirdly, we proposed a new method for estimating outflow of a continuous-flow VAD using an ARX model. It was ascertained that the accuracy of the proposed method remained on a practical level for two weeks in an animal experiment. Finally, we developed a transcutaneous energy and signal transmission system by using a new special type of coil with a good decoupled characteristic between energy and information. An in vitro experiment indicated that the system is useful for applying to clinical situations because of its robustness against positional deviation.

  36. Development of an axial flow blood pump using a hydrodynamic pressure bearing

    MITAMURA Yoshinori, MURABAYASHI Shun, NISHIMURA Ikuya, OKAMOTO Eiji, YOZU Rhohei, YAMBE Tomoyuki

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (B)

    Institution: HOKKAIDO UNIVERSITY

    2002 - 2005

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    An axial flow blood pump was developed using a hydrodynamic pressure bearing, a magnetic fluid seal and a brushless direct current motor. This enabled contact-free rotation of the impeller without material wear. The motor rotor is directly connected to the impeller by a motor shaft. A hydrodynamic pressure bearing is installed on the motor shaft. The motor and the hydrodynamic bearing are housed in a cylindrical casing and are waterproofed by a magnetic fluid seal. The magnetic fluid seal was developed for use in an axial-flow blood pump. Sealing pressures at motor speeds of up to 10,000 rpm were measured with the seal immersed in water. The sealing pressure was above 400 mm Hg. The seal, installed in the pump, remained perfect for 60 days at a flow of 4 L/min against a pressure of 150 mmHg. Results of measurement of cell growth activity indicated that the magnetic fluid has no negative cytological effects. The developed blood pump could eject a flow of 5 L/min at a pressure difference of 100 mmHg with an allowable hemolysis level (N.I.H.<0.02). The axial flow blood pump was implanted in goats between the left ventricle and the descending aorta. The goat survived for two days and a total left ventricular bypass was obtained with the pump. A control system of the axial flow blood pump was developed. A prediction method of the pump flow based on power consumption of the motor and motor speed was proposed. Pump flow was predicted with an error of less than 10%. Backflow through the pump and obstruction of the inflow cannula were automatically detected based on the wave distortion rate of the motor current. The distortion rate was computed using the Walsh functions.

  37. Comprehensive research concerned with the influence of flow state of artificial heart on living body by observation of microcirculation

    IMACHI Kou, TAKIURA Koki, YAMBE Tomoyuki, ABE Yusuke, MOCHIZUKI Shuichi, SAITO Itsuro

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (S)

    2002 - 2005

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    Although many types of continuous flow ventricular assist devices have become to use clinically as the bridge to heart transplantation, no body knows whether the pulsatility of blood flow is essential for living body or not. We have succeeded the basic development to solve the problem ; undulation pump AH(UPAH) and CCD probe. UPAH can change instantaneously its flow patterns by computer control of motor rotational speed. CCD probe is implantable micro-camera to observe microcirculation chronically. The objective of this study is to clarify the necessity of pulsatility for the living body by developing more completely UPTAH and CCD probe. The following outcome has been gotten in these 4 years : 1)UPAH Blood compatibility, durability and size & weight were improved great deal. The goat implanted UPAH survived maximally 4 months without anticoagulant. The software to control blood waveform has also been developed. 2)CCD probe High magnification, focus adjust system and miniaturization were the objective to be developed. A micro-lens, 2 mm in diameter and 2 mm long was developed. The lens was installed into a CCD camera having 8 mm in diameter and 60 mm long. Total magnification on 14 inch TV screen was 650 times, that was enough to observe the erythrocyte flow in a capillary vessel. It could be implanted in an animal without difficulty. Residual problem is focus adjusting system. 3)Microcirculation under UPAH The blood flow pattern was changed instantaneously from pulsatile to continuous when UPAH goat recover from surgical stress. The microcirculation was observed at bulbar conjunctiva during experiment. Following phenomena were observed until now : (1)Capillary density that is the ratio of the flowing capillaries to total capillary number, was decreased 30%. (2)The erythrocyte flow rate in the capillary was decreased 75 and some of them did not recover after the flow pattern returned to pulsatile.

  38. 埋め込み型インテリジェント人工心筋の開発

    山家 智之, 江刺 正喜, 圓山 重直, 吉澤 誠, 仁田 新一, 松木 英敏

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 萌芽研究

    Institution: 東北大学

    2002 - 2004

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    本年度は,人工心筋装置の長期動物実験の達成を目標として研究を進めた.エレクトロハイドローリック型心室補助装置を開発した.合成高分子材料を用いた心室モデルを用いて循環シミュレーションを行い,装置設計段階から心室補助装置による血行力学的補助効果を想定し,同システムの開発を行った.開発した埋め込み式心室補助装置は,成山羊第4-5肋間に固定され,動物実験で評価したところ生理学的に有効な補助効果を確認することができた. 4ヶ月以上継続した慢性実験4例においては,人工物の移植に起因すると想われる若干の炎症は観察されたものの,腎臓・肝臓・肺にはうっ血の所見は見られなかった.装置が設置された心筋表面にはうっ血所見がみられたが,ミクロ微細構造変化の観察はより専門的観点からの検討が必要と考えられた.過熱冷却能力が一定ならば,形状記憶合金のスケール(サイズ)が小さいほど,熱力学的効率が高く,速い収縮拡張動作が得られることに着目して,独自に開発した形状記憶合金及びファイバー型形状記憶合金(Biometal)とペルチェ素子を組み合わせて微小収縮補助装置を開発した.まず,縦1mm横0.8mm長さ100mmの形状記憶合金ロッド側面にペルチェ素子50個が搭載されたシートを接着し,ヒートシンクを有した構造とした心筋補助装置素子を作成した.このシステムでは,体内環境を模擬した電気絶縁性溶液内において1W,1Hzの動作を実現できた.さらに,直径150μmのナノテク形状記憶ファイバーを並列接続として収縮力評価を行った結果,ペルチェ冷却素子と併合したシステムによって最大で2Hz程度の収縮拡張運動を達成することができた.動物実験では,両形状記憶合金型システムの挙動を確認し,心室壁面への装着が充分に可能であることが分かった.生体心臓の収縮挙動に対する人工的収縮位相の最適化について,検討を進める必要があることが示された.

  39. Development of Noninvasive Estimation system of Maximum Ventricular Elastance Emax for Clinical Application

    YOSHIZAWA Makoto, YAMBE Tomoyuki, ABE Kenichi, NITTA Shin-ichi, TANAKA Akira, SAIJO Yoshifumi

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (C)

    Institution: Tohoku University

    2002 - 2003

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    The maximum ventricular elastance (Emax) is a good quantitative index for evaluating cardiac pump function. To extensively promote clinical application of Emax, it is necessary to need a new method for obtaining Emax without high invasive measurements. The purpose of this research was to develop a clinical method for estimating Emax low-invasively without any cardiac load on the of the parameter optimization method (POM) and the linear elastance method (LEM) that has been proposed by the authors. Because the POM and LEM need left ventricular pressure (LVP) and aortic flow (AoF), we have also developed a technique to estimate these signals in the following. First, the system we have developed can estimate LVP on the basis of two ARX (autoregressive exogeneous) models : the system model from radial arterial pressure (RdP) to aortic pressure (AoP) and the system model from AoP to LVP, respectively ; In a cardiac catheterization test, these ARX models can be identified by using LVP, AoP and RdP. LVP and AoP are invasive measurements but RdP is measured noninvasively by a tonometric pressure sensor. Once these models are identified, it is guessed that LVP can be estimated fully noninvasively by using RdP even after the previous cardiac catheterization test. Secondly, the developed system can estimate AoF by automatically extracting the contour of Doppler echocardiography during the ejection period. Finally, the total system has been completed in a personal computer unit so as to estimate Emax on the basis of the POM using the off-line data of RdP and the Doppler image of aortic flow rate. An input module has been added to the system to apply the system to real clinical use.

  40. Study of Remote early diagnosis system for malfunction of implantable artificial heart

    OKAMOTO Eiji, YANBE Tomoyuki, YOSHIZAWA Makoto, MITAMURA Yoshinori

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (C)

    Institution: Hokkaido Tokai University

    2001 - 2003

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    We have studied early diagnosis system for detecting symptom of malfunction of an implanted artificial heart before threatening patients' life. The early diagnosis system consists of a electro-stethoscope and a mobile computer. Sound signal generated by an artificial heart is an index of the degree of mechanical deterioration, because the sound signal is related to the condition of each mechanical components of the artificial heart. Sound data, which are detected on the surface of the body of a discharged patient in whom a TAK has been implanted. are transmitted to a host computer in a hospital via a mobile telephone (PHS). The early diagnosis system has two type of unique filters 1) an optimum frequency characteristics of low-pass filter based on simulating sound transmission characteristics of tissue, and 2) adaptive noise canceller, in order to eliminate ambient sound signal mixed in artificial heart's sound signal. The early diagnosis system was able to detect symptom of pump malfunction in in-vivo experiment using a goat implanted an undulation pump total artificial heart. The results of this study showed that the early diagnosis system contributes to improvement in the quality of life of discharged artificial heart patients by ensuring their safety.

  41. Development of Intravascular Acoustic Microscopy System

    SAIJO Yoshifumi, KANAI Hiroshi, YAMBE Tomoyuki, NITTA Shin-ichi, OKADA Nagaya, OHTSUKI Shigeo

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (B)

    Institution: Tohoku University

    2001 - 2003

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    The cause of acute coronary syndromes such as acute myocardial infarction or unstable angina has been revealed as the rupture of a vulnerable plaque in a coronary artery. The objective of the research project was to develop an intravascular acoustic microscope system applicable to clinical settings. The concrete purpose during the term of Grant-in Aid for Scientific Research was to establish an ultrasonic diagnostic system with 40 MHz frequency which can provide greater information compared with a conventional intravascular ultrasound (IVUS) system. The radio-frequency (RF) signal from a conventional IVUS apparatus was digitized by a high speed A/D converter with a sampling frequency of 500 MSa/s. The ECG and intracoronary pressure were simultaneously digitized and stored in a workstation. Conventional IVUS images and Integrated Backscatter Imaging derived from automatic sensitivity time compensation. RF signals of the same portion in consecutive frames were analyzed and correlation and displacement were calculated. Tissue Velocity Imaging was defined as two-dimensional distribution of the displacement in 1/30 sec where the correlation was 0.7 or more. Tissue Strain Imaging was derived from the tissue velocity difference between two points considering intracoronary pressure change. Normal coronary artery, soft plaque and hard plaque were visualized by the system. The strain of the soft plaque was larger than that of normal coronary artery and the strain was greatly changed during one cardiac cycle. The clinical results suggest the efficiency of the system to assess the pathophysiology of acute coronary syndromes.

  42. Artificial Anal Sphincter using Shape Memory Alloys

    TAKAGI Toshiyuki, LUO Yun, YAMABE Tomoyuki

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (B)

    Institution: Tohoku University

    2001 - 2003

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    Following results and achievements have been attained in this project. 1)In the first fiscal year of the project, we established the protocol of animal experiments for colostomy with piglets, implanted prototypes of the artificial sphincters under the stomas, and were successful in short-term animal experiments in the respects of basic functions : the closing and opening functions of the device. 2)The second year of the project was devoted to the development of a transcutaneous energy transmission system and overheating prevention equipment in order to realize a complete implantation of the device. Animal experiments with periods of up to 4 weeks were carried out using these equipments. The healthy situation of the animal (piglet) in these experiments was confirmed. Moreover, ordinary evacuation was observed almost each time when the artificial sphincter was activated in open. 3)The optimum design about the dimension and shape of the artificial sphincter was conducted. With the improved prototypes implanted into animals, the monitoring of the inner pressure was carried out with a pressure sensor inserted in the closed intestine. It was found that with the occlusion pressure ranging from 50 to 60mmHg, the device had sufficient closing function without any damage of ischemia. 4)As a result of the careful design of the overheating protection and thermal insulation in materials and dimension, even when artificial sphincter was heated to open for a period longer than 10 min., it was able to control the temperature of its surface in contact with surrounding tissues to be lower than the maximum allowed temperature of living tissue,40℃. The occlusion pressure and surface temperature of the device are two most important criterions in the assessment of the device. The success in solving these two problems in this project will facilitate the commercialization of the device in near future.

  43. Development of a physiologically effective control system for an artificial heart based on autonomic nerve activity

    NITTA Shin-ichi, KONNO Satoshi, SAIJO Yoshifumi, YAMBE Tomoyuki, TANAKA Akira, YOSHIZAWA Makoto

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (A)

    Institution: Tohoku University

    2000 - 2003

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    In recent years, the application of Ventricular Assist Devices (VAD) has been gradually expanded due to the lack of heart donors and increasing morbidity of cardiovascular diseases. However, there hasn't been an established method for controlling VAD/Total Artificial Heart (TAH) system which can provide physiologically effective circulatory support for a prolonged period of time. Although most investigators adopted an approach to controlling VAD/TAH according to cardiac output or aortic pressure, these conventional methods are not fully reflecting circulatory responses and are reported to occur long-term complications such as thyroid dysfunction or increased central venous pressure. To solve this issue, we newly developed a biocompatible stainless-steel neural interface and successfully recorded autonomic nerve activity of an awake VAD-implanted goat for more than a month. Then we applied fractal dimension analysis, a non-linear analysis method suitable for evaluating complicated biological information, to quantify the changes in autonomic nerve activities. As a result, shifts of the fractal dimension of autonomic nerve activity were observed in response to the changes in circulatory dynamics and posture of animals. Based on the analysis of recorded autonomic nerve activities, a real-time VAD/TAH control system by using fractal analysis-based feedback control algorithm was constructed. Now we attempt to examine the validity of this algorithm and improve it through animal experiments.

  44. Control of Aging by the use of Artificial Organs

    YAMBE Tomoyuki, SAIJO Yoshifumi, NITTA Shin-ichi, YOSHIZAWA Makoto, TABAYASHI Kou-ichi, TANAKA Akira

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (B)

    Institution: Tohoku university

    1999 - 2002

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    Since an aging society comes unescapable, we cope with various diseases by the Aging, and have the necessity of aiming at the society where healthy elderly people play an active part. Although an Aging phenomenon can also be considered to be change of the whole body, in the medical spot, it servers as generating of the illness of an internal-organs unit. The illnesses of an internal-organs unit are various medicines and adaptation of a surgical operation. To the internal-organs malfunction which has advanced irreversibl, radical correspondence of transplantation, an artificial organ, etc. becomes indispensable to life maintenance. Therefore, a possibility that support of high-tech medical treatments, such as an articial organ, will become unescapable at the healthy aging society is high. It is becoming old memory with collapse of the Communist bloc that the long-term struggle for existence of the animal experiment of an artificial heart was performed having applied national prestige all over the world. There is an opinion about which it whispered between the artificial heart researchers in the world from that time. It is "aging of the animal after implanting an artificial heart is early ?" It is the hypothesis to say. To pathophysiological change which can be regarded also as promotion of such an Aging after implanting an artificial heart, the syndrome of a "artificial heart syndrome" was proposed in the University of Tokyo. Research on change of the heart blood vessel system in connection with various artificial circulation and Agings has been done even in Tohoku University. The Institute of Development, Aging and Cancer in Tohoku University carried out the research subject "the nonlinear analysis of the artificial heart animal as an Aging promotion model" by the support of the test research from the Ministry of Education science research cost. Cousequently, the artificial heart chronic animal as an Aging promotion model was established. Based on this result, the Ministry of Education, Culture, Sports, Science and Technology science research cost base research "research on control of the Aging phenomenon by chaos control of an artificial organ" was done from 1999 to 2003. Our results suggested the feasibility of control of Aging by the use of the artificial organs.

  45. Development of Low-Invasive Estimation System of Maximum Ventricular Elastance E_<max> Based on Parameter Optimization Method

    YOSHIZAWA Makoto, YAMBE Tomoyuki, ABE Ken-ichi, NITTA Shin-ichi

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (C)

    Institution: Tohoku University

    2000 - 2001

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    The maximum ventricular elastance (E_<max>) is a good quantitative index for evaluating cardiac pump function. If E_<max> can be obtained low-invasively, it will strongly contribute to test and diagnosis of ischemic heart diseases and so on. However, the clinical application of E_<max> has not extensively progressed because the conventional methods for obtaining E_<max> need high invasive measurements. The purpose of this research was to develop a clinical method for estimating E_<max> low-invasively without any cardiac load on the basis of the parameter optimization method (POM) which has already proposed by the authors. The POM needs left ventricular pressure (LVP) and aortic flow (AoF). First, the system we have developed can estimate LVP on the basis of two ARX (autoregressive exogeneous) models : the system model from radial arterial pressure (RdP) to aortic pressure (AoP) and the system model from AoP to LVP, respectively. In a cardiac catheterization test, these ARX models can be identified by using LVP, AoP and RdP. LVP and AoP are invasive measurements but RdP is measured noninvasively by a tonometric pressure sensor. Once these models are identified, it is guessed that LVP can be estimated fully noninvasively by using RdP even after the previous cardiac catheterization test. Secondly, the developed system can estimate AoF by automatically extracting the contour of Doppler echocardiography during the ejection period. Finally, the total system has been completed in a personal computer unit so as to estimate E_<max> on the basis of the POM using the off-line data of RdP and the Doppler image of aortic flow rate. However, an input module has to be added to the system to apply the system to real clinical use.

  46. Creation of New Research Field and Industry Using Thermoelectric Actuators

    MARUYAMA Shigenao, MATSUMOTO Minoru, KOHAMA Yasuaki, TAKAGI Toshiyuki, ESASHI Masayoshi, YAMBE Tomoyuki

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for University and Society Collaboration

    Institution: Tohoku University

    1999 - 2001

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    The introduction of intelligent actuators into various medical devices can not only reduce the risk in medical operations, but also decrease th* affliction of patients, therefore becomes an important issue in recent medical research. The continuously increasing needs of such intelligen medical systems require developments of new actuators in aspects of the higher quality of life. The main goal of this research project is t** establish medical systems based on two intelligent elements; shape memory alloys (SMAs) and Peltier modules, considering their applications t** adaptive catheters and artificial muscles. Shape Memory Alioys have attracted large interest in engineering fields since their discovery at the beginning of 1960s. Their particula* properties ; the shape memory effect (SME) and the pseudoelasticity are proposed to be used for thermomechanical sensors, actuators and othe* intelligent systems. The great advantage of using SMAs in sensor and actuator systems is that they can be operated actively through th* thermomechanical energy conversion, therefore this fact leads to simple designs. Their other features ; compact, lightweight and larg* force-to-weight ratio make them specially suitable to be used in medical devices. A Peltier module has a function io transfer heat rapidly whe* DC current is applied. It is widely used in specialized electronics applications, such as cooling infrared detectors and solid-state lasers. Th* combination of SMAs and Peltier modules can produce new actuators with high frequency responses, which is a drawback in conventional SM actuators. This report describes the development process of the adaptive catheters and the artificial muscles for artificial heart systems and show* main results obtained from various experiments and simulations including, a) evaluations of thermomechanical properties of the therrnoelectric actuators for active catheters, b) evaluations of thermomechanical properties of the thermoelectrical actuators for artificial heart muscles, and optimal operation of the systems for the actuators. Main achievements attained in the research project can be summarized as followings : a) A precise control system for applied current and the sensing/monitoring of temperatures of actuators has been developed. b) An SMA-Peltier elements combined catheter, which possesses functions of both the bending and twisting, has been developed. c) An SMA-Peltier elements combined artificial heart muscle with a frequency response of up to 1HZ has been developed. d) Numerical simulation will give us optimal conditions for operating system, with using one-dimensional heat conduction model considering t** physical properties.

  47. インターネットを用いた心機能のリアルタイムカオス解析

    山家 智之

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 奨励研究(A)

    Institution: 東北大学

    1998 - 1999

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    本研究の目的は、全く新しい循環制御系の診断法の確立を目指して、インターネット回線を介したネットワークによるリアルタイム診断が可能な、心機能のカオス解析システムの完成を期することである。そのためにAQ法による心内膜自動解析により左室内膜の自動解析を行って左室の一回拍出量を求め、その時系列情報を病院内のイントラネットらしくはインターネツト回線でコンピュータに転送し、解析結果を再びネットワーク回線で伝えるリアルタイムの診断システムの開発を試みた。そのために加齢医学研究所附属病院超音波検査室の超音波診断装置の心内膜自動解析によって解析される左室内腔の容量を、時系列曲線として取り出すことができるように、現有の超音波診断装置に改造を加えた。得られた時系列曲線はリアルタイムで、パーソナルコンピュータ内にADコンバータを介して読み込み、1心拍毎のRR間隔と1回拍出量の時系列データに変換するシステムを試作した。このシステムによって、パーソナルコンピュータ内で定量化、統計計算の他、非線形力学を応用したカオス解析が具現化した。更に特筆される研究成果はトノメトリ法にと同時計測することにより末梢血管抵抗のリアルタイム計測が具現化したことであり、心臓支配自律神経と血管運動支配自律神経を独立して解析することが可能になったので、より詳細な循環機能計測、神経機能計測が可能になった。この成果は新聞やテレビなどマスコミにも取り上げられ注目されている。本解析システムにより生体から非侵襲的に、かつ実時間的に左室容量の時系列曲線を得ることができるようになり、多くの興味深い知見が得られた。特に左室のストロークボリュームの時系列変動におけるカオス性が発見され、生体の非線形ダイナミクスを解析する上で非常に興味深いとともに、診断学的な新しい意義も示唆された。本研究によって全く新しい画期的な循環機能、自律神経機能診断法が確立すると同時に、今後膨大なデータ処理が必要になることが自明である医療分野に、インターネットを応用した医療情報処理の新しい方法論が確立されうるものと期待される。

  48. Development of Low-Invasive Estimation System of Maximum Ventricular Elastance Emax Under Assisted Circulation

    YOSHIZAWA Makoto, YAMBE Tomoyuki, ABE Ken-ichi, NITTA Shin-ichi

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (C)

    Institution: Tohoku University

    1997 - 1998

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    The maximum ventricular elastance (Emax) will be a good quantitative index for weaning the patient from the ventricular assist device if the Emax can be obtained low-invasively. The purpose of this research was to develop a method for estimating the Emax beat-to-beat and less-invasively. First, it was formulated that the process for estimating the Emax is a kind of inverse problem. This leaded to an algorithm for estimating the Emax beat-to-beat on the basis of only two measurements : ventricular pressure and ventricular volume or aortic flow. Second, the algorithm was implemented on a personal computer system to calculate Emax in a real-time fashion. Third, the animal experiments using goats were carried out in many situations with change in preload and afterload or with injections for changing cardiac function. The data obtained from the experiments)showed that the correlation coefficient of the Emax between the proposed method and the traditional method was about 0.9. This indicates that the proposed method is sufficiently useful for monitoring cardiac function. Furthermore, it could be shown that the proposed method is superior to the traditional methods because the estimation error can be evaluated quantitatively as an error with respect to the intercept of the end-systolic pressure volume regression line. To apply the proposed method to actual clinical settings, the proposed method must be further improved so that another less-invasive information like aortic pressure instead of ventricular pressure can be used for estimating the Emax.

  49. Developmental Research of Learning and Adaptive Control System for Artificial Hearts

    ABE Ken-ichi, YAMBE Tomoyuki, MATSUKI Hidetoshi, YOSHIZAWA Makoto, NITTA Shin-ichi

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (A)

    Institution: Tohoku University

    1996 - 1998

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    The purpose of this research was to develop a learning and adaptive control system of artificial hearts whose reference model is the cardiovascular center in the brain and to enable the system to carry out an artificial circulatory control, coping with the cardiovascular system whose structure and parameters are unknown and time varying. First, a control algorithm of total artificial heart (Peripheral Vascular Resistance-Based Adaptive Control ; PVRBAC) was developed. This algorithm could make the controller be reflected by the autonomic nervous system via the peripheral vascular resistance (PVR). This may be because the decoupling control is used to remove the effect of the PVR on aortic pressure. This may enable the cardiovascular center to control cardiac output by manipulating the PVR. Second, a controller for animal experiments based on the above algorithm was implemented in a personal computer system. An experimental system named effectively total artificial heart system was used to ascertain the adequacy of the PVRBAC.From this system, it could be shown that the contribution of right atrial pressure to heart rate was as good as that of aortic pressure. This implies that the PVRBAC is adequate because it uses the PVR consisting of both right atrial pressure and aortic pressure. Third, it was shown that the PVRBAC is feasible for continuous-flow artificial heart as well as pulsatile-flow one. This indicates that the PVRBAC is versatile and does not depend on the kind of blood pump or drive type.

  50. DRUG DELIVERY SYSTEM BY THE CONTROL OF BLOOD FLOW DISTRIBUTION USING ARTIFICIAL CIRCULATION WITH OSCILLATED BLOOD FLOW

    NITTA Shin-ichi, FUKUTOME Akira, HIYAMA Hirokuni, YAMBE Tomoyuki

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (A)

    Institution: Tohoku University

    1995 - 1997

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    High frequency oscillated blood flow is a typical sine-wave blood flow within 10-40 Hz. It has a higher driving frequency compared with the natural heart beats. Oscillated blood flow may be useful for the new type drug delivery system from its unique driving effects. It may be possible to control the blood flow distribution by the control of driving frequency of oscillated blood flow. In this study, hemodynamic parameters were measured and estimated during artificial circulation using oscillated blood flow. Systemic vascular resistance were decreased by the start of vibrating flow pump. It may show the oscillatory effect for vascular tension by the artificial circulation using oscillated blood flow. Left common carotid arterial blood flow rate were increased by the change of driving frequency without the no change of pump output rate. The arterial impedance were estimated in this study. The branch, curve and stenosis are the major origin of reflect wave, and these points are important for the arterial impedance study. Each organ may have the suitable frequency from its physical characteristics, input impedance study may clear these characters. Blood flow distribution may be controlled by the driving frequency of oscillated blood flow, if we can make the suitable driving frequency for the target organ. The appropriate frequency driving for the target organ may generate the physiological resonance. The artificial circulation using high frequency oscillated blood flow may become the one of the new type drug delivery system.

  51. 人工現実感が自律神経機能に与える影響

    山家 智之, 杉山 由樹, 吉澤 誠

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 重点領域研究

    Institution: 東北大学

    1996 - 1996

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    新しいテクノロジーとして近年とみに注目を集めつつある人工現実感の技術は、特にアミューズメント関係の分野などにおいて脚光を浴びつつある。しかしながら例えばコンピュータディスプレイにおける長時間の光刺激などによって青少年に発生する光過敏性てんかん、いわゆるファミコンてんかん等の問題に代表されるように、人工現実感などの新しいヒューマンインターフェースが生体に与える影響を明らかにすることは、医学的にも社会的にも重要な問題となりつつある。そこで我々は前年度まで人工現実感が生体に与える影響を明らかにするために種々の実験を行い、主として循環動態のゆらぎ成分等の解析を通じて、多くの報告を行ってきた。その結果、恐怖感をあおるソフトウェアなどにおいて主として交感神経系に影響が観察されることなどについて明らかにしてきた。またカオス的なダイナミクスの特徴的であるストレンジアトラクターの再構築によるフラクタル次元解析などにより、生体の非線形動特性に人工現実感が与える影響について研究を行ってきた。しかしながらこれらの観察は、間接的な観察にとどまっているという批判は否定しきれない。本年度はかかる点を鑑み、交感神経活動を直接計測することにより、人工現実感が自律神経に与える影響を直接的に解明することを目標とした。健常成人男子7例を対象に実験を行った。安静臥位でHMDを装着し、約10分間ずつ、ビデオによる視聴覚刺激を与えた。ソフトウェアの内容は、ジェットコースターなどの恐怖感をあおる場面を編集したコンテンツと、風景が流れれいくだけの刺激の少ないコンテンツの二種類である。これらを安静臥位におけるコントロールデータと比較検討を行った。実験対象の7例のうち、4例において安定した計測が可能であった。一例は筋交感神経ニューログラムの計測が不可能であった。また一例は,HMDの装着後吐き気を訴え、実験を中止した。また最後の一例はどうしてもタングステン微小電極を脛骨神経に刺入できず、皮膚交感神経の記録になった。安定した計測が可能であった4例では有意の不整脈などは観察されず、血行動態のうえからも安定しているのが観察された。ニューログラムの変化を観察したところ、交感神経トーヌスにはVRのコンテンツ間の有意な差は認められなかった。しかしながら皮膚交感神経が記録された一例では、コンテンツ間の極端な差が観察されており、血管抵抗など内蔵機能を支配する筋交感神経には差がなくても、皮膚の発汗などを支配する皮膚交感神経に差が認められたという事は、交感神経の地域性反応などの問題とも合わせ、非常に興味深い結果と思われた。

  52. Non-destructive detection of material fatigue in artificial heart by ultrasonic spectroscopy.

    NITTA Shin-ichi, KANAI Hiroshi, KUSHIBIKI Jun-ichi, YAMBE Tomoyuki

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (B)

    Institution: Tohoku University

    1995 - 1996

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    Left ventricular assist device (LVAD) has been clinically applied for the treatment of severe heart failure in recent years. As the period of using LVAD is expanded to nearly one year, the detection of material damage has been necessitated. In order to detect the material fatigue, low frequency ultrasonic properties of the material were assessed by the frequency domain analysis of the pulsed ultrasound, and the surface morphology of the material was visualized by the acoustic microscopy. A3.5 MHz linear transducer was placed above the sample in a water tank. The system was modified to access to the rf signals at the output of the time gain controlled (TCG) amplifier, before any significant nonlinear processing, such as compression or rectification, was performed. To observe the frequency dependent characteristics of the received pulse, the Fast Fourier Transform (FFT) of the data was computed. The significant differences of FFT waveforms were observed between new and fatigued materials. Ultrasonic method could detect the material fatigue, although the appearance and the thickness of the samples did not show significant change. A specially developed scanning acoustic microscope system, operating in the frequency range of 100-200MHz, was employed. In the amplitude image of new material, there were no significant cracks or abnormal structure on the surface. Although the surface seemed to be smooth in the amplitude image, the surface was found to be distorted in the phase image. Very small crack and abnormal powder structure was detected in the amplitude image. In the phase image, the distortion was more prominent than that of new material. Both in low and high frequencies, ultrasonic approaches to evaluate the material revealed the material damage. Although this study was performed in the static condition, ultrasonic method should be used in the beating condition in the next stage investigation.

  53. Nonlinear analysis of the hemodynamics in the artificial heart animals as the aging acceleration model

    YAMBE Tomoyuki, YOSHIZAWA Makoto, MIURA Makoto, ABE Ken-ichi, NITTA Shin-ichi

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (B)

    Institution: Tohoku University

    1994 - 1996

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    The population composition of this country shifts to old age. Accordingly investigation of essence of "Aging" phenomenon is urgent business. Aging progresses in the whole of biological system. Thus, it is thought that it can't be elucidated by the reduction theory which was the mainstream in the past scientifis research. It is thought that application of the methodology of an analysis that established point of view with the whole system becomes necessary. In the animals with total artificial hearts, many pathophysiological changes such as Hypertension, elevation of central venous pressure, alteration of humoral factor, had been reported in some institutions. So, an artificial heart animal was positioned as "Aging acceleration model". A change in the time series courve of hemodynamics of an artificial heart animal was observed with the chronic experiment using healthy adult goats. In this research, analysis by the nonlinear dynamics which paid attention to dynamic characteristic of the whole system was used. Major research result was mentioned in the following. 1. Establishment of procedure of the biometrics that nonlinear mechanics was applied was tried. 2. Non-linear analysis of the hemodynamics with chronic experimental artificial heart animals. Comparison examination with hemodynamics by a natural heart was done. 3. Autonomic nerve activity recording was carried out in the artificial heart animals. 4.Long term survival experiment of artificial heart chronic experimental animals were carried out. The change that artificial heart control algorithrm gave to this physiology was observed. Consideration was added about the hemodynamics which was the optimum which controlled aging.

  54. 人工現実感が自律神経機能に与える影響

    山家 智之, 杉山 由樹, 吉澤 誠

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 重点領域研究

    Institution: 東北大学

    1995 - 1995

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    Virtual realityによる人工現実感が生体の自律神経機能に与える影響を解析するために、Head mounted displayを装着した生体における心拍変動及び血圧変動を記録した。その時系列曲線を、A-D convertorを介してpersonal computerに入力し、ゆらぎ成分について解析を行った。種々のソフトウエアを用いた人工現実感が生体に与える影響を解析するために、様々なビデオソフトを用い、更に従来の方法と比較検討するために、通常の市販されているテレビとの比較検討を行った。その結果、特に過敏な症例などにおいてはジェットコースター等の恐怖感をあおる人工現実感においては、通常のテレビの視聴と比較しても、心拍変動のLF/HF比等が著明な影響を受けていることが判明し、自律神経系が人工現実感に影響を受けている可能性が示唆されていた。これらの変化がいかなる自律神経活動の変動を反映しているのか確認するために、健常成人を対象に、種々の体位における心拍変動や血圧等の循環動態を、脛骨神経に刺入したタングステン微小電極を用いて記録した筋交感神経活動の時系列曲線と同時記録した。その結果、循環動態と交換神経活動のトーヌスは、体位の変換等により著明な影響を受けていることが判明し、この0.1Hz前後のMayer wave変動成分は、交感神経活動のトーヌスとかなり強い相関を持っていることが判明した。この相関はスペクトル解析法における関連度関数によって、筋交感神経と循環動態時系列曲線との間に強い線形性が認められることからも示唆されていた。従って、恐怖感をあおるVirtual realityによる人工現実感が、生体に与える循環動態の変動は交感神経系のトーヌスの増大によって起こされている可能性が強いものと考えられた。

  55. 心機能動態のフラクタル次元解析による加齢現象の定量化

    山家 智之

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 奨励研究(A)

    Institution: 東北大学

    1994 - 1994

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    種々の年齢層の健常ボランテイアを対象に、超音波心臓診断法を用いて左室の収縮時系列曲線を記録し、パーソナルコンピュータに入力し、定量化、統計処理を行なうと同時に、非線形数学理論を用いて高次元位相空間内へ埋め込んでアトラクターを再構築した。カオス理論を用いてリアプノフ指数の解析を行ない、KSエントロピー及びフラクタル次元を求めカオスアトラクターの定量化を行なった。 種々の方法論を用いて左室の収縮時系列曲線の自動解析による定量化を試みたが、長時間安定した計測は自動解析では困難であったので、本年度はトレーシングペーパーにMモード像における左室内径をトレースし、イメージリーダーでパーソナルコンピュータに入力した。得られた時系列曲線をTakensの方法論によって高次元位相空間内へ埋め込んでアトラクターを再構築した。タイムラグは時系列曲線の自己相関関数の計算によって決定した。 その結果、左室収縮アトラクターの再構築には3次元以上の位相空間が必要であり、リアプノフ指数の計算による初期値依存性の判定から、左室壁運動がカオス的な挙動を示していることが明らかとなった。更に、老化の進行に応じてフラクタル次元やKSエントロピーが変化するのが観察され、非線形数学数学理論による加齢現象の定量化の可能性が示唆された。また心筋梗塞等の疾患群ではリアプノフ次元の有意の減少が観察され、心機能の判定法としても有用な方法論になりうるものと期待された。このような方法論によって心機能を支配する循環制御系の全体論的な解析が可能になるものと考えられた。

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Social Activities 3

  1. [日本国内] 第7回宮城社会保険病院連携の集い

    2010/02/05 - Present

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    脈波伝播速度とCAVIの予防医学への応用

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    2013/02/28 -

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    多賀城市学校保険会

  3. [日本国内] 栗原医師会学術講演会

    2010/01/21 -

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    脈波解析の予防医学への応用

Media Coverage 7

  1. [日本国内] 健康カー 心電図血圧測定も

    秋田さきがけ新聞

    2009/11/16

    Type: Newspaper, magazine

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    車に乗ってハンドルを握れば、心血管系の異常が診断でき、治療も可能な健康カーが開発されている

  2. [日本国内] 健康カーで体調管理

    岐阜新聞

    2009/11/07

    Type: Newspaper, magazine

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    車に乗ってハンドルを握れば、心血管系の異常が診断でき、治療も可能な健康カーが開発されている

  3. [日本国内] ハンドル握り健康管理

    中国新聞

    2009/11/02

    Type: Newspaper, magazine

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    車に乗ってハンドルを握れば、心血管系の異常が診断でき、治療も可能な健康カーが開発されている

  4. [日本国内] ハンドル握って体調管理

    下野新聞

    2009/10/31

    Type: Newspaper, magazine

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    車に乗ってハンドルを握れば、心血管系の異常が診断でき、治療も可能な健康カーが開発されている

  5. [日本国内] ハンドルが体調確認

    岩手日報

    2009/10/29

    Type: Newspaper, magazine

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    車に乗ってハンドルを握れば、心血管系の異常が診断でき、治療も可能な健康カーが開発されている

  6. [日本国内] 健康カー

    熊本日日新聞

    2009/10/27

    Type: Newspaper, magazine

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    車に乗ってハンドルを握れば、心血管系の異常が診断でき、治療も可能な健康カーが開発されている

  7. [日本国内] 健康カー開発へ

    東奥日報

    2009/10/26

    Type: Newspaper, magazine

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    車に乗ってハンドルを握れば、心血管系の異常が診断でき、治療も可能な健康カーが開発されている

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