顔写真

オオタ マコト
太田 信
Makoto Ohta
所属
流体科学研究所 流動創成研究部門 生体流動ダイナミクス研究分野
職名
教授
学位
  • 博士(工学)(京都大学)

  • 修士(工学)(京都大学)

経歴 4

  • 2022年3月 ~ 継続中
    東北大学 大学院医工学研究科 教授

  • 2022年3月 ~ 継続中
    東北大学 大学院工学研究科 教授

  • 2001年9月 ~ 2004年12月
    ジュネーブ大学 ポスドク

  • 2001年4月 ~ 2001年9月
    京都大学再生医科学研究所 講師(研究機関研究員)

学歴 2

  • 京都大学 工学研究科 高分子化学科

    ~ 2001年3月

  • 東京農工大学 工学部 物質生物工学科

    ~ 1995年3月24日

委員歴 25

  • 医療用立体モデルコンソーシアム 幹事

    2019年8月 ~ 継続中

  • 戦略的国際標準化加速事業・政府戦略分野に係わる国際標準開発活動「バイオセラミックスの生物学的多能性評価に関する国際標準化」 委員

    2019年4月 ~ 継続中

  • 日本機械学会 A-TS 02-04 制御と情報-生体への応用研究会 主査

    2019年4月 ~ 継続中

  • ISO/TC150/WG14 議長

    2018年10月 ~ 継続中

  • 日本生体医工学会 東北支部 役員

    2018年4月 ~ 継続中

  • ISO/TC150 国内委員会 委員

    2016年4月 ~ 継続中

  • 機械学会バイオエンジニアリング部門 A-TS02-16 脳神経血管内治療に関する医工学連携研究会 主査

    2016年2月 ~ 継続中

  • 日本機械学会 編集委員

    2013年1月 ~ 継続中

  • 経済産業省事業「AMによる患者適合型支援システム造形に関する国際標準」 委員

    2020年4月 ~ 2023年3月

  • PMDA第4期科学委員会「コンピューターシミュレーションを活用した医療機器ソフトウエアの審査の考え方」専門部会 委員

    2019年4月 ~ 2021年3月

  • 日本機械学会 東北支部 55期 商議委員 会計幹事

    2019年4月 ~ 2021年3月

  • 日本機械学会 日本機械学会2019年度 学術誌編修部会 委員 日本機械学会論文集/Transactions of the JSME (in Japanese), Mechanical Engineering Journal, Mechanical Engineering Letters.

    2019年4月 ~ 2020年3月

  • 海綿骨モデルを含脊椎骨周辺のモデルの力学的測定方法に関する国際標準化委員会 PI

    2017年4月 ~ 2019年3月

  • Intracranial Stent Meeting HP管理

    2009年9月 ~ 2018年3月

  • 次世代医療機器・再生医療等製品評価指標作成事業 血流解析シミュレーションソフトウェア分野 審査ワーキンググループ 委員

    2016年4月 ~ 2018年

  • 模擬骨の3次元構造体に要求される特性に関する国際標準化委員会 PI

    2014年4月 ~ 2016年3月

  • PMDA(独立行政法人 医薬品医療機器総合機構)科学委員会委員 委員

    2014年4月 ~ 2016年

  • 外科用インプラント、これに関連する器具及び計装装置の検査等に用いる力学的安全性評価用模擬骨に関する国際標準化委員会 PI

    2011年4月 ~ 2014年3月

  • 日本機械学会 バイオエンジニアリング部門 運営委員会

    2010年4月 ~ 2012年3月

  • 日本機械学会 バイオエンジニアリング部門 運営委員会

    2010年4月 ~ 2012年3月

  • Intra cranial stent meeting 2006 (ICS06) Program organizer of Intra cranial stent meeting 2006 (ICS06)

    2005年3月 ~ 2006年9月

  • Intra cranial stent meeting 2006 (ICS06) Intra cranial stent meeting 2006 (ICS06)のプログラム委員

    2005年3月 ~ 2006年9月

  • Intra cranial stent meeting 2004 (ICS04) oranizer of Intra cranial stent meeting 2004

    2004年10月 ~ 2005年1月

  • Intra cranial stent meeting 2004(ICS04) Intra cranial stent meeting 2004の実行委員

    2004年10月 ~ 2005年1月

  • Intracranial Stent Meeting admin of Web site

    2009年9月 ~

︎全件表示 ︎最初の5件までを表示

所属学協会 3

  • 日本バイオレオロジー学会

  • 日本生体医工学会

  • 日本機械学会

研究キーワード 7

  • 口腔

  • 摩耗

  • 血管内治療

  • 動脈瘤

  • 血流

  • 3次元再構築

  • 生体モデル

研究分野 4

  • ライフサイエンス / 脳神経外科学 /

  • ものづくり技術(機械・電気電子・化学工学) / 流体工学 /

  • ライフサイエンス / 生体材料学 /

  • ライフサイエンス / 生体医工学 /

受賞 20

  1. 日本機械学会フェロー

    2021年2月 日本機械学会

  2. Poster Award(13th International IntraCranial Stent Meeting

    2016年11月27日 13th International IntraCranial Stent Meeting Correlating MR Wall Enhancement and Wall Shear Stress: Does CFD work to predict aneurysm instability?

  3. Poster Award(13th International IntraCranial Stent Meeting

    2016年11月27日 13th International IntraCranial Stent Meeting Exploring the relationship between the inflow zone and strut positions within the aneurysm orifice: a hemodynamic simulation study

  4. Poster Award(13th International IntraCranial Stent Meeting

    2016年11月27日 13th International IntraCranial Stent Meeting Blood Flow Into Basilar Tip Aneurysms A Predictor for Recanalization After Coil Embolization

  5. 東北大学藤野先生記念奨励賞

    2016年9月27日 東北大学

  6. ポスターアワード(生体医工学シンポジウム2016

    2016年9月18日 生体医工学シンポジウム Introduction of Evaluation of Endoleak in Ink Flow Study

  7. Best Student Presentation Award

    2015年11月14日 ICS2015 Student Presentation Award

  8. Student Presentation Award

    2015年11月14日 ICS2015

  9. ElyT Workshop 2014 best poster award

    2015年2月20日 ElyT best poster award

  10. Intracranial Stent Meeting 2012(ICS 2012) Best Abstract Presentation

    2012年11月20日 ICS2012

  11. Intracranial Stent Meeting 2012(ICS 2012)

    2012年11月20日 ICS2012 Best Abstract Presentation

  12. 教育助成金プログラム 2011年度アジア部門1位

    2012年11月4日 エドモンド・オプティクス・ジャパン株式会社 PVAを用いた脳動脈瘤モデルにおける壁挙動とPIV計測

  13. 第23回日本脳神経血管内治療学会 ポスター銀賞

    2007年11月 第23回日本脳神経血管内治療学会

  14. 第23回日本脳神経血管内治療学会 優秀演題

    2007年11月 第23回日本脳神経血管内治療学会

  15. Young Investigator Award

    2005年11月21日 The 6th International Symposium on Future Medical Engineering based on Bio-nanotechnology (21st Century COE Program) Development of a Functional Vessel Biomodelling with Poly (vinyl alcohol) Hydrogel for In-vitro Simulation

  16. 2005年第20回日本脳血管内治療年学会 銅賞

    2004年11月 第20回日本脳血管内治療年学会 Measurement of intra-aneurysmal flow dynamics at stent implant

  17. 第20回日本脳血管内治療年学会 銅賞

    2004年11月 第20回日本脳血管内治療年学会 シネマティックアンジオを用いた、脳動脈瘤内の血流速さ測定法の開発(第一報)

  18. ポスター賞

    2004年9月 European Society of Neuroradiology ステントのストラッド径、ストラッド、effective postioningが脳動脈瘤内の血流に与える影響:有限要素法による解析

  19. 2003年第19回日本脳血管内治療年学会 銀賞

    2003年11月 第19回日本脳血管内治療年学会 ステントのセルデザインが脳動脈瘤内の血流に与える影響:有限要素法による解析

  20. Dr. Fernando Vinuela賞

    2002年6月 14th Society of International Latin America Neuroradiology ステントが脳動脈瘤内の血流に与える影響

︎全件表示 ︎最初の5件までを表示

論文 359

  1. Elongation of the proximal descending thoracic aorta and associated hemodynamics increase the risk of acute type B aortic dissection. 国際誌

    Xuelan Zhang, Yuan Peng, Gaoyang Li, Jiehua Li, Mingyao Luo, Yue Che, Liancun Zheng, Hitomi Anzai, Makoto Ohta, Chang Shu

    Technology and health care : official journal of the European Society for Engineering and Medicine 2023年8月3日

    DOI: 10.3233/THC-230194  

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    BACKGROUND: Acute type B aortic dissection (ATBAD) is a life-threatening aortic disease. However, little information is available on predicting and understanding of ATBAD. OBJECTIVE: The study sought to explore the underlying mechanism of ATBAD by analyzing the morphological and hemodynamic characteristics related to aortic length. METHODS: The length and tortuosity of the segment and the whole aorta in the ATBAD group (n= 163) and control group (n= 120) were measured. A fixed anatomic landmark from the distal of left subclavian artery (LSA) to the superior border of sixth thoracic vertebra was proposed as the proximal descending thoracic aorta (PDTA), and the dimensionless parameter, length ratio, was introduced to eliminate the individual differences. The significant morphological parameters were filtrated and the associations between parameters were investigated using statistical approaches. Furthermore, how aortic morphology influenced ATBAD was explored based on idealized aortic models and hemodynamic-related metrics. RESULTS: The PDTA length was significantly increased in the ATBAD group compared with the control group and had a strong positive correlation with the whole aortic length (r= 0.89). The length ratio (LR2) and tortuosity (T2) of PDTA in the ATBAD group were significantly increased (0.15 ± 0.02 vs 0.12 ± 0.02 and 1.73 ± 0.48 vs 1.50 ± 0.36; P< 0.001), and LR2 was positive correlation with T2 (r= 0.73). In receiver-operating curve analysis, the area under the curve was 0.835 for LR2 and 0.641 for T2. Low and oscillatory shear (LOS) was positive correlation with LR2, and the elevated LOS occurred in the distal of LSA. CONCLUSION: Elongation of PDTA is associated with ATBAD, and the length ratio is a novel predictor. Elongated PDTA induced more aggressive hemodynamic forces, and high LOS regions may correspond to the entry tear location. The synergy of the morphological variation and aggressive hemodynamics creates contributory conditions for ATBAD.

  2. Computational Fluid Dynamics Simulation to Investigate Diffuser Outlet Factors in Anaerobic Membrane Bioreactors Treating Wastewater

    Haoran Wang, Makoto Ohta, Hitomi Anzai, Jiayuan Ji

    SUSTAINABILITY 15 (15) 2023年8月

    出版者・発行元:MDPI

    DOI: 10.3390/su151511959  

    eISSN:2071-1050

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    Anaerobic membrane bioreactors (AnMBRs) require biogas recycling to stir the mixed liquid and flush particles away from the membrane surfaces for stable operation. With the fixed gas cycling rate, gas diffuser configuration is an important factor that affects stirring and flushing performance. This study investigated the effect of different outlet diameters on biogas diffusers in AnMBR by using computational fluid dynamics (CFD) to analyze gas-liquid flow in a numerical model constructed based on an experimental AnMBR. According to the CFD results, as the outlet diameter increased from 2.5 to 5.0 mm, the average velocity increased from 0.15 to 0.31 m/s and the average wall shear stress (WSS) increased from 0.21 to 1.10 Pa on the membrane surface. The increase in gas velocity enhances the stirring effect, and the increase in WSS improves the flushing performance. However, when it was further increased to 10.0 mm, the average velocity and average WSS was 0.27 m/s and 0.22 Pa, respectively, indicating that too large an outlet diameter leads to a concentrated gas distribution, which reduces the performance of stirring and flushing. Furthermore, these results provide a basis for optimizing diffuser configuration, which is significant for promoting the practical application of AnMBR in wastewater treatment.

  3. Ultrasound flow phantom for transcranial Doppler: An assessment of angular mismatch effect on blood velocity measurement in comparison to optical particle image velocimetry 査読有り

    Muhammad Shiddiq Sayyid Hashuro, Kotaro Daibo, Takuro Ishii, Yoshifumi Saijo, Makoto Ohta

    Frontiers in Physics 11 2023年4月6日

    出版者・発行元:Frontiers Media SA

    DOI: 10.3389/fphy.2023.1134588  

    eISSN:2296-424X

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    Detecting abnormal blood flow is possible through transcranial Doppler (TCD) ultrasound by measuring blood velocity in cerebral arteries. Velocity measurements are at the highest precision when the direction of blood flow coincides with the ultrasound beam. However, because TCD is typically performed blindly (i.e., without a B-mode), a 0° interrogation angle is usually assumed. This leads to a common issue of angular mismatch. This study quantitatively shows the angular mismatch effects on the measured velocities using a TCD ultrasound flow phantom compared with the velocities measured by optical particle image velocimetry (PIV) as control. Resulting errors with and without ultrasound machine angular correction were also considered. An ultrasound phantom developed by combining polyvinyl alcohol hydrogel (PVA-H), quartz glass as a scatterer, and a gypsum plate as a skull bone was utilized to approximate the middle cerebral artery TCD measurement from the temporal window. The PVA-H and quartz glass compositions were controlled to achieve transparency and enable PIV velocity measurement. Then, TCD velocity measurement was conducted on several interrogation and mismatch angles. Comparison results revealed that without an ultrasound machine angle correction, all measurements yielded underestimation with 73.9% at the highest in the 80° interrogation window at the 130 mL/min flow. On the other hand, with the correction, the errors in almost all angles were comparatively lower; however, at 80° at the 124 mL/min flow, a maximum overestimation rate of 113.7% was found, showing a larger error magnitude. Therefore, we find that angular mismatch, especially in larger angles, leads to inaccurate velocity measurements in TCD. Our results suggest that despite angle correction, velocity errors may still occur when the interrogation angle changes.

  4. Effects of helical centerline stent vs. straight stent placement on blood flow velocity. 国際誌

    Yutaro Kohata, Makoto Ohta, Kazuyoshi Jin, Hitomi Anzai

    Frontiers in medical technology 5 1196125-1196125 2023年

    DOI: 10.3389/fmedt.2023.1196125  

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    As an approach to maintain patency in femoropopliteal stenting, a helical stent configuration was proposed, which showed improved patency in clinical trials. However, the effects of helical stent placement on the flow have not been quantitatively analyzed. The purpose of this study was to estimate flow velocities to quantify the influence of helical stent placement. Helical and straight stents were implanted in three healthy pigs, and the flow velocities were estimated using the time-intensity curve (TIC) in the angiography images. The angiographic images indicated thinning of the leading edge of the contrast medium through the helically deformed artery, which was not observed in the straight stent. The slower rise of the TIC peak in the helical stent indicated faster travel of this thinner edge. Arterial expansion due to stenting was observed in all cases, and the expansion rate varied according to location. All cases of helical stent implantation showed that velocity was maintained (55.0%-71.3% velocity retention), unlike for straight stent implantation (43.0%-68.0% velocity retention); however, no significant difference was observed.

  5. Migration of endothelial cells on the surface of anodized Ni-Ti stent strut. 国際誌 査読有り

    Zi Wang, Naofumi Ohtsu, Kasumi Tate, Yukiko Kojima, Hanif Saifurrahman, Makoto Ohta

    Frontiers in medical technology 5 1149594-1149594 2023年

    DOI: 10.3389/fmedt.2023.1149594  

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    BACKGROUND: Stent is widely regarded as the main treatment for curing cardiovascular diseases such as stenosis. Previous research has revealed that the damage of endothelial cells (EC), i.e., the components of endothelium, during stent implantation, could lead to severe complications, such as restenosis. To prevent restenosis, enhancements have been made to surface biocompatibility to accelerate the stent endothelialization process. Anodization on the Ni-Ti is a simple and efficient surface modification method to improve the biocompatibility of the Ni-Ti stent surfaces by enhancing the surface hydrophilicity, leading to an increase in the EC activities. The EC activity is known to be affected by the blood flow. Flow change by stent structure may result in EC dysfunctions, thereby leading to restenosis. It is thus essential to investigate the EC activities resulting from the anodization on the Ni-Ti surface under flow conditions. OBJECTIVE: To study the influence of the endothelialization process on the Ni-Ti stent surface through anodization. The EC attachment and morphology on the anodized stent strut were observed under both with and without the flow conditions. METHOD: A parallel plate flow chamber was designed to generate a constant wall shear stress (WSS) to study the flow effect on the EC behavior. The hydrophilicity of the Ni-Ti stent strut surface was enhanced by a TiO2 layer fabricated via anodization. The EC distribution on the surface of the anodized nitinol stent strut was observed after 24 h of static (without flow) and flow exposure (with flow) experiment. RESULTS: Under the static condition, the EC density on the surface of the anodized Ni-Ti stent strut was higher compared with the control. Under the flow condition, the enhancement of the EC density on the surface of the stent strut with anodization was reduced. The EC demonstrates a long and thin spindle-shaped morphology under the flow condition. CONCLUSION: Unlike the static condition, the EC is demonstrating a long and thin morphology in response to the flow under the flow condition. By improving the surface hydrophilicity, the anodization could enhance the EC migration onto the strut surface, and subsequently, accelerate the Ni-Ti stent endothelialization process. The improvement of the surface hydrophilicity is lower under the flow conditions when compared with the static conditions.

  6. Development of Ultrasound Phantom Made of Transparent Material: Feasibility of Optical Particle Image Velocimetry 国際誌 査読有り

    Muhammad Shiddiq Sayyid Hashuro, Simon Tupin, Narendra Kurnia Putra, Kotaro Daibo, Kosuke Inoue, Takuro Ishii, Hiroyuki Kosukegawa, Kenichi Funamoto, Toshiyuki Hayase, Makoto Ohta

    Ultrasound in Medicine and Biology in press (6) 1385-1394 2023年

    DOI: 10.1016/j.ultrasmedbio.2022.12.020  

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    OBJECTIVE: The need for ultrasound flow phantoms to validate ultrasound systems requires the development of materials that can clearly visualize the flow inside for measurement purposes. METHODS: A transparent ultrasound flow phantom material composed of poly(vinyl alcohol) hydrogel (PVA-H) with dimethyl sulfoxide (DMSO) and water solution manufactured using the freezing method and mixed with quartz glass powder to exhibit scattering effects is proposed. To achieve transparency of the hydrogel phantom, the refractive index (RI) was changed to match that of the glass by modifying the PVA concentration and the ratio of DMSO to water in the solvent. The feasibility of optical particle image velocimetry (PIV) was verified by comparing an acrylic rectangular cross-section channel with a rigid wall. After the feasibility tests, an ultrasound flow phantom was fabricated to conduct ultrasound B-mode visualization and Doppler-PIV comparison. DISCUSSION: The results revealed that the PIV measured through PVA-H material exhibited 0.8% error in the measured maximum velocity compared with PIV through the acrylic material. B-mode images are similar to real tissue visualization with a limitation of a higher sound velocity, when compared with human tissue, of 1792 m/s. Doppler measurement of the phantom revealed approximately 120% and 19% overestimation of maximum and mean velocities, respectively, compared with those from PIV. CONCLUSION: The proposed material possesses the advantage of the single-phantom ability to improve the ultrasound flow phantom for validation of flow.

  7. Numerical simulation to evaluate guidewire and catheter behavior during catheter introduction 査読有り

    Kazuto TAKASHIMA, Akinori NAMBA, Hiroto OTA, Yoichi HAGA, Makoto OHTA, Koji MORI, Naoki TOMA, Masaaki SHOJIMA

    Bulletin of the JSME Journal of Biomechanical Science and Engineering 18 (1) 1-12 2022年12月

    DOI: 10.1299/jbse.22-00276  

  8. Coupled discrete phase model and Eulerian wall film model for numerical simulation of respiratory droplet generation during coughing 国際誌 査読有り

    Hitomi Anzai, Yugo Shindo, Yutaro Kohata, Masahiro Hasegawa, Hidemasa Takana, Tetsuro Matsunaga, Takaaki Akaike, Makoto Ohta

    Scientific reports 12 (1) 14849-14849 2022年9月1日

    DOI: 10.1038/s41598-022-18788-3  

    eISSN:2045-2322

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    Computational fluid dynamics is widely used to simulate droplet-spreading behavior due to respiratory events. However, droplet generation inside the body, such as the number, mass, and particle size distribution, has not been quantitatively analyzed. The aim of this study was to identify quantitative characteristics of droplet generation during coughing. Airflow simulations were performed by coupling the discrete phase model and Eulerian wall film model to reproduce shear-induced stripping of airway mucosa. An ideal airway model with symmetric bifurcations was constructed, and the wall domain was covered by a mucous liquid film. The results of the transient airflow simulation indicated that the droplets had a wide particle size distribution of 0.1-400 µm, and smaller droplets were generated in larger numbers. In addition, the total mass and number of droplets generated increased with an increasing airflow. The total mass of the droplets also increased with an increasing mucous viscosity, and the largest number and size of droplets were obtained at a viscosity of 8 mPa s. The simulation methods used in this study can be used to quantify the particle size distribution and maximum particle diameter under various conditions.

  9. A Software to Visualize, Edit, Model and Mesh Vascular Networks. 国際誌

    Meghane Decroocq, Guillaume Lavoue, Makoto Ohta, Carole Frindel

    Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual International Conference 2022 2208-2214 2022年7月

    DOI: 10.1109/EMBC48229.2022.9871365  

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    Computational fluid dynamics (CFD) is a key tool for a wide range of research areas, beyond the computer science community. In particular, CFD is used in medicine to measure blood flow from patient specific models of arteries. In this field, the creation of accurate meshes remains the most challenging step, as it is based on the segmentation of medical images, a time-consuming task which often requires manual intervention by medical doctors. In this context, user-friendly, interactive softwares are valuable. They enable to spread the new advances in numerical treatment to the medical community and enrich them with the expert knowledge (e.g anatomical knowledge) of clinicians. In this work, we present a user interface dedicated to the meshing of vascular networks from centerlines. It allows for the 3D visualization and edition of input centerlines, which constitute a simplified, easy-to-manipulate representation of vascular networks. The surface of the artery can be reconstructed from the modified centerlines by an editable parametric model and then meshed with high quality hexahedral elements. At every step of the process, the network can be confronted with medical images with enhanced visualization. The software will be released publicly. Clinical relevance- This tool facilitates the manual extraction and editing of vascular networks by medical doctors. It opens the generation of hexahedral meshes for computational fluid dynamics studies to non-expert users.

  10. Experimental Study of Collateral Patency following Overlapped Multilayer Flow Modulators Deployment 査読有り

    Simon Tupin, Kei Takase, Makoto Ohta

    Fluids 7 (7) 220-220 2022年6月30日

    出版者・発行元:MDPI AG

    DOI: 10.3390/fluids7070220  

    eISSN:2311-5521

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    Decades after its introduction, endovascular aneurysm repair remains a challenging procedure with risks of collateral patency failure. Here, we investigate the ability of a porous stent, the Multilayer Flow Modulator (MFM), to maintain renal perfusion after a single or overlapping case. Silicone models representing an ideal infrarenal AAA geometry were used to analyze and compare three cases (control, single MFM and two overlapped MFMs). Micro-computed tomography was used to image the deployed MFM devices geometry and evaluate pore size and density along with porosity in both two (planimetric) and three dimensions (gravimetric). Laser particle image velocimetry (PIV) experiments were performed to image velocity and vorticity fields at the aorta-renal bifurcation. Flow experiments revealed renal arteries perfusion preservation in both single and overlapped cases. Microstructure analysis revealed an uneven distribution of wires in the MFM devices leading to local change in planimetric porosity and pore size. Overlap of a second MFM device led to a significant decrease in those 2D metrics but did not affect the gravimetric porosity and the branch perfusion. This first microstructure evaluation of MFM device combined with flow experiments revealed the ability of the device to preserve collateral flow thanks to a highly porous microstructure.

  11. A Parametric Study of Flushing Conditions for Improvement of Angioscopy Visibility 査読有り

    Kohei Mitsuzuka, Yujie Li, Toshio Nakayama, Hitomi Anzai, Daisuke Goanno, Simon Tupin, Mingzi Zhang, Haoran Wang, Kazunori Horie, Makoto Ohta

    JOURNAL OF FUNCTIONAL BIOMATERIALS 13 (2) 2022年6月

    出版者・発行元:MDPI

    DOI: 10.3390/jfb13020069  

    eISSN:2079-4983

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    During an angioscopy operation, a transparent liquid called dextran is sprayed out from a catheter to flush the blood away from the space between the camera and target. Medical doctors usually inject dextran at a constant flow rate. However, they often cannot obtain clear angioscopy visibility because the flushing out of the blood is insufficient. Good flushing conditions producing clear angioscopy visibility will increase the rate of success of angioscopy operations. This study aimed to determine a way to improve the clarity for angioscopy under different values for the parameters of the injection waveform, endoscope position, and catheter angle. We also determined the effect of a stepwise waveform for injecting the dextran only during systole while synchronizing the waveform to the cardiac cycle. To evaluate the visibility of the blood-vessel walls, we performed a computational fluid dynamics (CFD) simulation and calculated the visible area ratio (VAR), representing the ratio of the visible wall area to the total area of the wall at each point in time. Additionally, the normalized integration of the VAR called the area ratio (AR(VAR)) represents the ratio of the visible wall area as a function of the dextran injection period. The results demonstrate that the AR(VAR) with a stepped waveform, bottom endoscope, and three-degree-angle catheter results in the highest visibility, around 25 times larger than that under the control conditions: a constant waveform, a center endoscope, and 0 degrees. This set of conditions can improve angioscopy visibility.

  12. 血管内治療デバイス留置シミュレータの開発—(コイル挿入条件の影響)

    大石 卓弥, 高嶋 一登, 葭中 潔, 于 凱鴻, 太田 信, 森 浩二, 当麻 直樹

    バイオフロンティア講演会講演論文集 2022.32 1C24 2022年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebiofro.2022.32.1c24  

    eISSN:2424-2810

  13. Evaluation of Normalization Methods in a Cerebral Artery Atlas for Automatic Labeling

    Kazuyoshi Jin, Ko Kitamura, Shunji Mugikura, Naoko Mori, Makoto Ohta, Hitomi Anzai

    Volume 5: Biomedical and Biotechnology 2021年11月1日

    出版者・発行元:American Society of Mechanical Engineers

    DOI: 10.1115/imece2021-71097  

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    Abstract An existence probability atlas has been used for automatic labeling of cerebral arteries. However, the number of arteries varies frequently because of image quality and individual variation of the artery structure. To moderate the influence of number imbalance on labeling accuracy, we propose a new normalized atlas for automatic labeling of cerebral artery centerlines. The number of arteries, which was obtained from magnetic resonance angiography, varies from 11 to 46 among the artery sites. Based on the centerline and diameter, the arterial volume was reconstructed into a voxel space for each subject. After superimposing arteries from 46 subjects, three normalization methods were compared: dividing by the number of subjects (N), by N and the arterial length (L), and by N and the arterial volume (V). To compare the labeling accuracy and precision, the summation of probability and labeling method was also used. The accuracy of all normalization methods was &amp;gt; 85% in all arteries. The precision improved in some parts, with the atlas normalized by N-L and by N-V. The use of N-L and N-V changed the relative value of the existence probability among the parts. Consequently, some normalization methods changed the tendency toward misclassification, which changed the precision.

  14. Assessment of the thermal outcome during steam-pulse ablation for sheep tissue

    Hitomi Anzai, Rolf Stämpfli, Adriano Wang-Leandro, Luciano F. Boesel, Shelley Kemp, Rene M. Rossi, Agnieszka A. Karol, Makoto Ohta, Henning Richter

    Thermal Science and Engineering Progress 25 100966-100966 2021年10月

    出版者・発行元:Elsevier BV

    DOI: 10.1016/j.tsep.2021.100966  

    ISSN:2451-9049

  15. Experimental Analysis of Pressure and Flow Alterations During and After Insertion of a Multilayer Flow Modulator into an AAA Model with Incorporated Branch 国際誌 査読有り

    Simon Tupin, Kei Takase, Makoto Ohta

    CardioVascular and Interventional Radiology 44 (8) 1251-1259 2021年8月27日

    出版者・発行元:Springer Science and Business Media {LLC}

    DOI: 10.1007/s00270-021-02835-z  

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    PURPOSE: The multilayer flow modulator (MFM) device has been used for the treatment of abdominal aortic aneurysm (AAA) for over a decade. Although several clinical studies have been published, criticism and concern over the device efficacy remain, as no quantitative analysis that describes its mechanism has been performed yet. The aim of this study was to experimentally evaluate the effect of MFM device deployment on aneurysmal pressure and branch perfusion. MATERIALS AND METHODS: An experimental flow and pressure monitoring system was developed to analyze the MFM deployment procedure performed by a qualified radiologist in AAA geometries with and without side branch. Particle image velocimetry experiments were then conducted on models with and without MFM device to evaluate and compare flow patterns and local flow velocity and vorticity in the aneurysm. RESULTS: The experiments revealed no significant change in pressure and flow rate during and after deployment of the MFM device. The flow rate of the incorporated branch was fully preserved. On both models, the aneurysmal flow velocity was significantly reduced. In addition, the device modified local flow patterns, reducing vorticity and better feeding the incorporated branch. CONCLUSION: This experimental study provides the basis for a better understanding of the mechanism of the MFM device, which allows intra-aneurysmal flow to decrease while preserving incorporated branch flow and reducing the risk of type II endoleak. The experimental system developed for this study was effective in simulating an endovascular procedure and studying the safety and effectiveness of endovascular devices.

  16. Finite element analysis of the mechanical performance of a zinc alloy stent with the tenon-and-mortise structure. 国際誌

    Sirui Wang, Dandan Wu, Gaoyang Li, Kun Peng, Yongliang Mu, Makoto Ohta, Hitomi Anzai, Aike Qiao

    Technology and health care : official journal of the European Society for Engineering and Medicine 2021年7月23日

    DOI: 10.3233/THC-212905  

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    BACKGROUND: Inadequate scaffolding performance hinders the clinical application of the biodegradable zinc alloy stents. OBJECTIVE: In this study we propose a novel stent with the tenon-and-mortise structure to improve its scaffolding performance. METHODS: 3D models of stents were established in Pro/E. Based on the biodegradable zinc alloy material and two numerical simulation experiments were performed in ABAQUS. Firstly, the novel stent could be compressed to a small-closed ring by a crimp shell and can form a tenon-and-mortise structure after expanded by a balloon. Finally, 0.35 MPa was applied to the crimp shell to test the scaffolding performance of the novel stent and meanwhile compare it with an ordinary stent. RESULTS: Results showed that the novel stent decreased the recoiling ratio by 70.7% compared with the ordinary stent, indicating the novel structure improved the scaffolding performance of the biodegradable zinc alloy stent. CONCLUSION: This study proposes a novel design that is expected to improve the scaffolding performance of biodegradable stents.

  17. Incomplete stent expansion in flow‐diversion treatment affects aneurysmal haemodynamics: a quantitative comparison of treatments affected by different severities of malapposition occurring in different segments of the parent artery 国際誌

    Mingzi Zhang, Yujie Li, Shin‐ichiro Sugiyama, David I. Verrelli, Yasushi Matsumoto, Teiji Tominaga, Yi Qian, Simon Tupin, Hitomi Anzai, Makoto Ohta

    International Journal for Numerical Methods in Biomedical Engineering 37 (7) e3465 2021年7月17日

    出版者・発行元:Wiley

    DOI: 10.1002/cnm.3465  

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    Incomplete stent expansion (IncSE) is occasionally seen in flow-diversion (FD) treatment of intracranial aneurysms; however, its haemodynamic consequences remain inconclusive. Through a parametric study, we quantify the aneurysmal haemodynamics subject to different severities of IncSE occurring in different portions of the stent. Two patient cases with IncSE confirmed in vivo were studied. To investigate a wider variety of IncSE scenarios, we modelled IncSE at two severity levels respectively located in the proximal, central, or distal segment of a stent, yielding a total of 14 treatment scenarios (including the ideal deployment). We examined stent wire configurations in 14 scenarios and resolved aneurysm haemodynamics through computational fluid dynamics (CFD). A considerable degradation of aneurysm flow-reduction performance was observed when central or distal IncSE occurred, with the maximal elevations of the inflow rate (IR) and energy loss (EL) being 10% and 15%. The underlying mechanism might be the increased resistance for flow to remain within the FD stent, which forces more blood to leak into the aneurysm sac. Counter-intuitively, a slight reduction of aneurysm inflow was associated with proximal IncSE, with the maximal further reduction of the IR and EL being 5% and 8%. This may be due to the disruption of the predominant parent-artery flow by the collapsed wires, which decreased the strength and altered the direction of aneurysmal inflow. The effects of IncSE vary greatly with the location of occurrence, revealing the importance of performing individualised, patient-specific risk assessment before treatment.

  18. Virtual Angiography System as a Platform for Blood Flow estimation

    LyonSE&N & ELyT workshop 2021 / JSPS Core to core 1st symposium Proceedings 33-34 2021年6月

  19. Tribology for health devices: 15 years of collaboration between Tohoku University (Ohta lab) and ECL (LTDS)

    M.Ohta, V. Fridrici

    LyonSE&N & ELyT workshop 2021 / JSPS Core to core 1st symposium 29-30 2021年6月

  20. CTA-Based Non-invasive Estimation of Pressure Gradients Across a CoA: a Validation Against Cardiac Catheterisation. 国際誌

    Mingzi Zhang, Jinlong Liu, Haibo Zhang, David I Verrelli, Qian Wang, Liwei Hu, Yujie Li, Makoto Ohta, Jinfen Liu, Xi Zhao

    Journal of cardiovascular translational research 14 (5) 873-882 2021年3月4日

    DOI: 10.1007/s12265-020-10092-7  

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    Non-invasive estimation of pressure gradients across a coarctation of the aorta (CoA) can reduce the need for diagnostic cardiac catheterisation. We aimed to validate two novel computational strategies-target-value approaching (TVA) and target-value fixing (TVF)-together with unrefined Doppler estimates, and to compare their diagnostic performance in identifying critical pressure drops for 40 patients. Compared to catheterisation, no statistically significant difference was demonstrated with TVA (P = 0.086), in contrast to TVF (P = 0.005) and unrefined Doppler echocardiography (P < 0.001). TVA manifested the strongest correlation with catheterisation (r = 0.93), compared to TVF (r = 0.83) and echocardiography (r = 0.67) (all P < 0.001). In discriminating pressure gradients greater than 20 mmHg, TVA, TVF, and echocardiography had respective sensitivities of 0.92, 0.88, and 0.80; specificities of 0.93, 0.80, and 0.73; and AUCs of 0.96, 0.89, and 0.80. The TVA strategy may serve as an effective and easily implemented approach to be used in clinical management of patients with CoA. Graphical Abstract Central illustration. Pressure gradients estimated using Doppler echocardiography and two novel computational strategies (TVA and TVF) were compared with cardiac catheterisation for 40 patients. TVA and TVF utilised the CTA images to obtain the CoA anatomy and Doppler echocardiography velocimetry to obtain velocity data for the assignment of CFD boundary conditions.

  21. Implementation of computer simulation to assess flow diversion treatment outcomes: systematic review and meta-analysis 国際誌 査読有り

    Mingzi Zhang, Simon Tupin, Hitomi Anzai, Yutaro Kohata, Masaaki Shojima, Kosuke Suzuki, Yoshihiro Okamoto, Katsuhiro Tanaka, Takanobu Yagi, Soichiro Fujimura, Makoto Ohta

    JOURNAL OF NEUROINTERVENTIONAL SURGERY 13 (2) 164-170 2021年2月

    出版者・発行元:BMJ PUBLISHING GROUP

    DOI: 10.1136/neurintsurg-2020-016724  

    ISSN:1759-8478

    eISSN:1759-8486

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    IntroductionDespite a decade of research into virtual stent deployment and the post-stenting aneurysmal hemodynamics, the hemodynamic factors which correlate with successful treatment remain inconclusive. We aimed to examine the differences in various post-treatment hemodynamic parameters between successfully and unsuccessfully treated cases, and to quantify the additional flow diversion achievable through stent compaction or insertion of a second stent.MethodsA systematic review and meta-analysis were performed on eligible studies published from 2000 to 2019. We first classified cases according to treatment success (aneurysm occlusion) and then calculated the pooled standardized mean differences (SMD) of each available parameter to examine their association with clinical outcomes. Any additional flow diversion arising from the two common strategies for improving the stent wire density was quantified by pooling the results of such studies.ResultsWe found that differences in the aneurysmal inflow rate (SMD -6.05, 95% CI -10.87 to -1.23, p=0.01) and energy loss (SMD -5.28, 95% CI -7.09 to -3.46, p<0.001) between the successfully and unsuccessfully treated groups were indicative of statistical significance, in contrast to wall shear stress (p=0.37), intra-aneurysmal average velocity (p=0.09), vortex core-line length (p=0.46), and shear rate (p=0.09). Compacting a single stent could achieve additional flow diversion comparable to that by dual-stent implantation.ConclusionsInflow rate and energy loss have shown promise as identifiers to discriminate between successful and unsuccessful treatment, pending future research into their diagnostic performance to establish optimal cut-off values.

  22. Prediction of 3D Cardiovascular hemodynamics before and after coronary artery bypass surgery via deep learning. 国際誌

    Gaoyang Li, Haoran Wang, Mingzi Zhang, Simon Tupin, Aike Qiao, Youjun Liu, Makoto Ohta, Hitomi Anzai

    Communications biology 4 (1) 99-99 2021年1月22日

    DOI: 10.1038/s42003-020-01638-1  

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    The clinical treatment planning of coronary heart disease requires hemodynamic parameters to provide proper guidance. Computational fluid dynamics (CFD) is gradually used in the simulation of cardiovascular hemodynamics. However, for the patient-specific model, the complex operation and high computational cost of CFD hinder its clinical application. To deal with these problems, we develop cardiovascular hemodynamic point datasets and a dual sampling channel deep learning network, which can analyze and reproduce the relationship between the cardiovascular geometry and internal hemodynamics. The statistical analysis shows that the hemodynamic prediction results of deep learning are in agreement with the conventional CFD method, but the calculation time is reduced 600-fold. In terms of over 2 million nodes, prediction accuracy of around 90%, computational efficiency to predict cardiovascular hemodynamics within 1 second, and universality for evaluating complex arterial system, our deep learning method can meet the needs of most situations.

  23. Emerging Technologies for Heart Diseases. 国際誌

    Makoto Ohta

    Technology and health care : official journal of the European Society for Engineering and Medicine 29 (5) 1047-1048 2021年

    DOI: 10.3233/THC-212909  

  24. 点群データを用いた血流予測ネットワークの予測精度に対する血管座標の影響

    白石 敬一郎, 太田 信, 安西 眸, リー ガオヤン

    生体医工学 Annual59 (Abstract) 510-510 2021年

    出版者・発行元:公益社団法人 日本生体医工学会

    DOI: 10.11239/jsmbe.annual59.510  

    ISSN:1347-443X

    eISSN:1881-4379

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    背景:大動脈と冠動脈の形状から内部の血行動態を短時間に予測するため,我々はディープラーニングネットワークモデルを開発した.しかしこのネットワークモデルはデータに対して位置のレジストレーションを行う必要があると考えられる.本研究では,入力データの位置のずれと予測精度の関係について調べた.方法:冠動脈性心疾患の患者110人の大動脈と冠動脈の形状データを使用した.これらの形状に変形を加えることで人工的に血管形状を作成し,データ数を1100個に拡張した.これらに対してCFDを行い,1000個をトレーニングデータ,100個をテストデータとした.予測精度は速度の平均二乗誤差(MSE)で評価した.トレーニングデータの存在する学習の内挿部分をトレーニング範囲と呼び,この範囲内外で一つのテストデータを移動させて,その予測精度を算出した.また範囲内での移動について,予測誤差の可視化をした.結果:トレーニング範囲内で平行移動させたとき,元の位置よりも精度が高くなる位置があった.範囲外に平行移動させたとき,ある位置から急激に精度が落ちていくような非線形の傾向があった.また,患者固有の流れが見られる部分で特に誤差が大きくなった.結論:我々の開発したネットワークモデルを使って血流予測を行う上で,位置のレジストレーションの重要性が示唆された.

  25. Numerical Simulation of Flow Behavior in Basilar Bifurcation Aneurysms Based on 4-Dimensional Computed Tomography Angiography

    Tomoaki Yamazaki, Gaku Tanaka, Ryuhei Yamaguchi, Yodai Okazaki, Hitomi Anzai, Fujimaro Ishida, Makoto Ohta

    World Journal of Mechanics 11 (04) 71-82 2021年

    出版者・発行元:Scientific Research Publishing, Inc.

    DOI: 10.4236/wjm.2021.114006  

    ISSN:2160-049X

    eISSN:2160-0503

  26. Association Between Aneurysmal Haemodynamics and Device Microstructural Characteristics After Flow-Diversion Treatments With Dual Stents of Different Sizes: A Numerical Study. 国際誌

    Mingzi Zhang, Simon Tupin, Yujie Li, Makoto Ohta

    Frontiers in physiology 12 663668-663668 2021年

    DOI: 10.3389/fphys.2021.663668  

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    Objectives: Treating intracranial aneurysms with flow-diverting stents sometimes requires deployment of a second device. Herein we quantify the sizing effects of devices in dual-stent treatments upon the final stent microstructure and the post-treatment aneurysmal haemodynamics. Methods: Fifteen sidewall ICA aneurysm geometries were included. Using a virtual stenting technique, we implanted either one or two stents for each aneurysm treatment considered, with each stent specified as one of two different sizes, yielding a total of two single-stent and fouir dual-stent treatment scenarios for each aneurysm. Three stent microstructural parameters and nine aneurysmal haemodynamic parameters were quantified and systematically compared across the 90 treatment scenarios. Results: Deployment of a second stent further reduced the aneurysmal inflow rate (IR) and energy loss (EL) by, respectively, 14 ± 11% (p = 0.001) and 9 ± 12% (p = 0.056), relative to the untreated condition. Sizing effects of the earlier-deployed stent led to largest differences of 6.9% for the final IR reduction and 11.1% for the EL, whereas sizing effects from the later-deployed stent were minor (≤2.1%). The change in stent pore size was the only microstructural parameter demonstrating a strong correlation with the reduction in the post-treatment aneurysmal haemodynamics, in terms of the IR (r = 0.50, p < 0.001) and pressure drop (r = 0.63, p < 0.001). Conclusion: Size of the earlier-deployed stent has substantial effects on the final haemodynamic outcomes after dual-stent treatment. The average pore size of stent wires at the aneurysm orifice shows promise as a potential index for predicting the efficacy of flow-diversion treatments.

  27. Flush Flow Behaviour Affected by the Morphology of Intravascular Endoscope: A Numerical Simulation and Experimental Study. 国際誌

    Yujie Li, Mingzi Zhang, Simon Tupin, Kohei Mitsuzuka, Toshio Nakayama, Hitomi Anzai, Makoto Ohta

    Frontiers in physiology 12 733767-733767 2021年

    DOI: 10.3389/fphys.2021.733767  

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    Background: Whilst intravascular endoscopy can be used to identify lesions and assess the deployment of endovascular devices, it requires temporary blockage of the local blood flow during observation, posing a serious risk of ischaemia. Objective: To aid the design of a novel flow-blockage-free intravascular endoscope, we explored changes in the haemodynamic behaviour of the flush flow with respect to the flow injection speed and the system design. Methods: We first constructed the computational models for three candidate endoscope designs (i.e., Model A, B, and C). Using each of the three endoscopes, flow patterns in the target vessels (straight, bent, and twisted) under three different sets of boundary conditions (i.e., injection speed of the flush flow and the background blood flowrate) were then resolved through use of computational fluid dynamics and in vitro flow experiments. The design of endoscope and its optimal operating condition were evaluated in terms of the volume fraction within the vascular segment of interest, as well as the percentage of high-volume-fraction area (PHVFA) corresponding to three cross-sectional planes distal to the microcatheter tip. Results: With a mild narrowing at the endoscope neck, Model B exhibited the highest PHVFA, irrespective of location of the cross-sectional plane, compared with Models A and C which, respectively, had no narrowing and a moderate narrowing. The greatest difference in the PHVFA between the three models was observed on the cross-sectional plane 2 mm distal to the tip of the microcatheter (Model B: 33% vs. Model A: 18%). The background blood flowrate was found to have a strong impact on the resulting volume fraction of the flush flow close to the vascular wall, with the greatest difference being 44% (Model A). Conclusion: We found that the haemodynamic performance of endoscope Model B outperformed that of Models A and C, as it generated a flush flow that occupied the largest volume within the vascular segment of interest, suggesting that the endoscope design with a diameter narrowing of 30% at the endoscope neck might yield images of a better quality.

  28. Endothelial Cell Distribution After Flow Exposure With Two Stent Struts Placed in Different Angles. 国際誌 査読有り

    Zi Wang, Narendra Kurnia Putra, Hitomi Anzai, Makoto Ohta

    Frontiers in physiology 12 733547-733547 2021年

    DOI: 10.3389/fphys.2021.733547  

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    Stent implantation has been a primary treatment for stenosis and other intravascular diseases. However, the struts expansion procedure might cause endothelium lesion and the structure of the struts could disturb the blood flow environment near the wall of the blood vessel. These changes could damage the vascular innermost endothelial cell (EC) layer and pose risks of restenosis and post-deployment thrombosis. This research aims to investigate the effect of flow alterations on EC distribution in the presence of gap between two struts within the parallel flow chamber. To study how the gap presence impacts EC migration and the endothelialization effect on the surface of the struts, two struts were placed with specific orientations and positions on the EC layer in the flow chamber. After a 24-h exposure under wall shear stress (WSS), we observed the EC distribution conditons especially in the gap area. We also conducted computational fluid dynamics (CFD) simulations to calculate the WSS distribution. High EC-concentration areas on the bottom plate corresponded to the high WSS by the presence of gap between the two struts. To find the relation between the WSS and EC distributions on the fluorescence images, WSS condition by CFD simulation could be helpful for the EC distribution. The endothelialization rate, represented by EC density, on the downstream sides of both struts was higher than that on the upstream sides. These observations were made in the flow recirculation at the gap area between two struts. On two side surfaces between the gaps, meaning the downstream at the first and the upstream at the second struts, EC density differences on the downstream surfaces of the first strut were higher than on the upstream surfaces of the second strut. Finally, EC density varied along the struts when the struts were placed at tilted angles. These results indicate that, by the presence of gap between the struts, ECs distribution could be predicted in both perpendicular and tiled positions. And tiled placement affect ECs distribution on the strut side surfaces.

  29. Evaluation of Contact Force between Aneurysm Model and Coil for Embolization of Intracranial Aneurysms

    Kazuto Takashima, Yuta Ikeda, Kiyoshi Yoshinaka, Makoto Ohta, Koji Mori, Naoki Toma

    Journal of Neuroendovascular Therapy 15 (4) 233-239 2021年

    出版者・発行元:The Japanese Society for Neuroendovascular Therapy

    DOI: 10.5797/jnet.oa.2020-0069  

    ISSN:1882-4072

    eISSN:2186-2494

  30. Hemodynamic and Flow Recirculation Effect on Rupture Prediction of Middle Cerebral Artery Aneurysm

    Nadia Shaira Shafii, Ryuhei Yamaguchi, Ahmad Zahran Md Khudzari, Gaku Tanaka, Atsushi Saitoh, Makoto Ohta, Kahar Osman

    Journal of Advanced Research in Fluid Mechanics and Thermal Sciences 79 (1) 1-16 2020年12月15日

    出版者・発行元:Akademia Baru Publishing

    DOI: 10.37934/arfmts.79.1.116  

    eISSN:2289-7879

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    The mortality and morbidity rate due to the severe effect of intracranial aneurysm (IA) is increasing, which has driven research trend on aneurysm rupture risk. By understanding the nature and causes of the aneurysm rupture, preventive measures could be taken in avoiding rupture besides recommending proper treatments such as endovascular coiling. However, the presence of flow recirculation causes the aneurysm wall to degenerate and weakened. The weakened wall is due to the haemodynamic factors such as velocity, wall shear stress (WSS), time average WSS (TAWSS), OSI and RRT, which were analysed in this study. In the present study, the flow model simulated a human patient-specific aneurysm at the apex of the bifurcation in the middle cerebral artery (MCA) in the transient state. Experimental results of full-scale models were collected on a median, side plane to study the flow behaviour and validation to the numerical simulation settings, which resulted in good agreement with only 8% difference. The simulation results obtained showed several interesting findings. The jet flow into the aneurysm led to complex vortex formation due to impinging flow behaviour within the aneurysm dome. Additionally, the area that recorded low velocity was at 30% of low TAWSS with only 1% of OSI that was more than 0.3, while the OSI critical value and 0.27% area exceeded RRT threshold, which caused the large oscillating blood flow direction and activated the atherosclerosis progression. These results suggest that the jet flow into the dome may cause further damage to the wall of the MCA aneurysm, which will help in providing an insight towards completing a guidance system assessment of rupture risk for medical practitioners in future work.

  31. Cerebrovascular Model Equipped with Microsensors

    Yoichi Haga, Hiroshi Yoshida, Tadao Matsunaga, Yasutomo Shimizu, Makoto Ohta, Masaaki Shojima, Taisuke Masuda, Kaihong Yu, Tupin Simon, Chenming Dai, Fumihito Arai, Kanako Harada

    IEEJ Transactions on Sensors and Micromachines 140 (12) 354-362 2020年12月1日

    出版者・発行元:Institute of Electrical Engineers of Japan ({IEE} Japan)

    DOI: 10.1541/ieejsmas.140.354  

    ISSN:1347-5525

  32. Epigenetic response of endothelial cells to different wall shear stress magnitudes: A report of new mechano-miRNAs. 国際誌 査読有り

    Sherif Rashad, Xiaobo Han, Khalid Saqr, Simon Tupin, Makoto Ohta, Kuniyasu Niizuma, Teiji Tominaga

    Journal of cellular physiology 235 (11) 7827-7839 2020年11月

    DOI: 10.1002/jcp.29436  

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    Endothelial cells (ECs) respond to flow stress via a variety of mechanisms, leading to various intracellular responses that can modulate the vessel wall and lead to diseases if the flow is disturbed. Mechano-microRNAs (miRNAs) are a subset of miRNAs in the ECs that are flow responsive. Mechano-miRNAs were shown to be related to atherosclerosis pathophysiology, and a number of them were identified as pathologic. Here, we exposed human carotid ECs to different wall shear stresses (WSS), high and low, and evaluated the response of miRNAs by microarray and quantitative polymerase chain reaction analysis. We discovered five new mechano-miRNAs that were not reported in that context previously to the best of our knowledge. Moreover, functional pathway analysis revealed that under low WSS conditions, several pathways regulating apoptosis are affected. In addition, KLF2 and KLF4, known atheroprotective genes, were downregulated under low WSS and upregulated under high WSS. KLF2 and VCAM1, both angiogenic, were upregulated under high WSS. NOS3, which is vascular protective, was also upregulated with higher WSS. On the contrary, ICAM-1 and E-selectin, both atherogenic and proinflammatory, were upregulated with high WSS. Collectively, the epigenetic landscape with the gene expression analysis reveals that low WSS is associated with a proapoptotic state, while high WSS is associated with a proliferative and proinflammatory state.

  33. Hemodynamic-Based Evaluation on Thrombosis Risk of Fusiform Coronary Artery Aneurysms Using Computational Fluid Dynamic Simulation Method

    Haoran Wang, Hitomi Anzai, Youjun Liu, Aike Qiao, Jinsheng Xie, Makoto Ohta, Zhihan Lv

    Complexity 2020 2020年10月20日

    出版者・発行元:WILEY-HINDAWI

    DOI: 10.1155/2020/8507273  

    ISSN:1076-2787

    eISSN:1099-0526

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    Coronary artery aneurysms (CAAs) have been reported to associate with an increased risk for thrombosis. Distinct to the brain aneurysm, which can cause a rupture, CAA's threat is more about its potential to induce thrombosis, leading to myocardial infarction. Case reports suggest that thrombosis risk varied with the different CAA diameters and hemodynamics effects (usually wall shear stress (WSS), oscillatory shear index (OSI), and relative residence time (RRT)) may relate to the thrombosis risk. However, currently, due to the rareness of the disease, there is limited knowledge of the hemodynamics effects of CAA. The aim of the study was to estimate the relationship between hemodynamic effects and different diameters of CAAs. Computational fluid dynamics (CFD) provides a noninvasive means of hemodynamic research. Four three-dimensional models were constructed, representing coronary arteries with a normal diameter (1x) and CAAs with diameters two (2x), three (3x), and five times (5x) that of the normal diameter. A lumped parameter model (LPM) which can capture the feature of coronary blood flow supplied the boundary conditions. WSS in the aneurysm decreased 97.7% apparently from 3.51 Pa (1x) to 0.08 Pa (5x). OSI and RRT in the aneurysm were increased apparently by two orders of magnitude from 0.01 (1x) to 0.30 (5x), and from 0.38 Pa-1 (1x) to 51.59 Pa-1 (5x), separately. Changes in the local volume of the CAA resulted in dramatic changes in local hemodynamic parameters. The findings demonstrated that thrombosis risk increased with increasing diameter and was strongly exacerbated at larger diameters of CAA. The 2x model exhibited the lowest thrombosis risk among the models, suggesting the low-damage (medication) treatment may work. High-damage (surgery) treatment may need to be considered when CAA diameter is 3 times or higher. This diameter classification method may be a good example for constructing a more complex hemodynamic-based risk stratification method and could support clinical decision-making in the assessment of CAA.

  34. Physiologic blood flow is turbulent. 国際誌

    Khalid M Saqr, Simon Tupin, Sherif Rashad, Toshiki Endo, Kuniyasu Niizuma, Teiji Tominaga, Makoto Ohta

    Scientific reports 10 (1) 15492-15492 2020年9月23日

    DOI: 10.1038/s41598-020-72309-8  

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    Contemporary paradigm of peripheral and intracranial vascular hemodynamics considers physiologic blood flow to be laminar. Transition to turbulence is considered as a driving factor for numerous diseases such as atherosclerosis, stenosis and aneurysm. Recently, turbulent flow patterns were detected in intracranial aneurysm at Reynolds number below 400 both in vitro and in silico. Blood flow is multiharmonic with considerable frequency spectra and its transition to turbulence cannot be characterized by the current transition theory of monoharmonic pulsatile flow. Thus, we decided to explore the origins of such long-standing assumption of physiologic blood flow laminarity. Here, we hypothesize that the inherited dynamics of blood flow in main arteries dictate the existence of turbulence in physiologic conditions. To illustrate our hypothesis, we have used methods and tools from chaos theory, hydrodynamic stability theory and fluid dynamics to explore the existence of turbulence in physiologic blood flow. Our investigation shows that blood flow, both as described by the Navier-Stokes equation and in vivo, exhibits three major characteristics of turbulence. Womersley's exact solution of the Navier-Stokes equation has been used with the flow waveforms from HaeMod database, to offer reproducible evidence for our findings, as well as evidence from Doppler ultrasound measurements from healthy volunteers who are some of the authors. We evidently show that physiologic blood flow is: (1) sensitive to initial conditions, (2) in global hydrodynamic instability and (3) undergoes kinetic energy cascade of non-Kolmogorov type. We propose a novel modification of the theory of vascular hemodynamics that calls for rethinking the hemodynamic-biologic links that govern physiologic and pathologic processes.

  35. Effects of wall compliance on multiharmonic pulsatile flow in idealized cerebral aneurysm models: comparative PIV experiments 査読有り

    Simon Tupin, Khalid M. Saqr, Makoto Ohta

    Experiments in Fluids 61 (7) 2020年7月

    出版者・発行元:Springer Science and Business Media {LLC}

    DOI: 10.1007/s00348-020-02998-4  

  36. Preliminary Study of Eye-Tracking During the Coil Insertion Task in a Silastic Model of Intracranial Aneurysms. 国際誌 査読有り

    Masaaki Shojima, Yoshihiro Okamoto, Makoto Ohta, Kuniyasu Niizuma, Nobuyuki Sakai, Teiji Tominaga

    World neurosurgery 139 e827-e835 2020年7月

    DOI: 10.1016/j.wneu.2020.05.012  

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    OBJECTIVE: Surgical skills are generally acquired by watching the "hand movements" of experts. "Eye movements" are now attracting attention in skill-learning fields. Eye-tracking technology was introduced preliminarily to develop a better skill-learning system for neuroendovascular treatments. METHODS: During a task to place a detachable coil into a silastic cerebral aneurysm model under biplane X-ray fluoroscopy, gaze points were recorded using a head-mount eye-tracking device. RESULTS: During the task, 91% of fixations were allocated to the monitor displaying fluoroscopic images, and the others to the hands of operators or unspecified visual targets. More than 80% of fixations were located in frontal or lateral fluoroscopic images. Fixations were placed more frequently around the aneurysm than the microcatheter. One operator failed to recognize the timing when the proximal marker of the coil overlapped that of the microcatheter. The subject allocated most fixations to the frontal fluoroscopic image, whereas other subjects placed most fixations to the lateral fluoroscopic image. Furthermore, that operator put no fixations to the proximal marker of the microcatheter. CONCLUSIONS: The results of this preliminary study imply the feasibility of the eye tracking-based learning system for neuroendovascular treatments. The eye-tracking analysis has potential in investigating or preventing procedural failures in neuroendovascular treatments.

  37. Haemodynamics in a patient-specific intracranial aneurysm according to experimental and numerical approaches: A comparison of PIV, CFD and PC-MRI. 国際誌

    Yujie Li, Yuuya Yoneyama, Haruo Isoda, Masaki Terada, Takafumi Kosugi, Takashi Kosugi, Mingzi Zhang, Makoto Ohta

    Technology and health care : official journal of the European Society for Engineering and Medicine 29 (2) 253-267 2020年6月19日

    DOI: 10.3233/THC-202252  

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    BACKGROUND: The haemodynamics determined by different approaches for studying fluid dynamics - i.e. computational fluid dynamics (CFD), particle image velocimetry (PIV), and phase-contrast magnetic resonance imaging (PC-MRI) - have rarely been thoroughly compared; nor have the factors that affect accuracy and precision in each method. As each method has its own advantages and limitations, this knowledge is important for future studies to be able to achieve valid analyses of fluid flows. OBJECTIVE: To gauge the capacity of these methods for analysing aneurysmal flows, we compared the haemodynamic behaviours determined by each method within a patient-specific aneurysm model. METHODS: An in vitro silicone aneurysm model was fabricated for PIV and PC-MRI, and an in silico aneurysm model with the same geometry was reconstructed for CFD. With the same fluid model prepared numerically and physically, CFD, PIV and PC-MRI were performed to study aneurysmal haemodynamics. RESULTS: 2D velocity vectors and magnitudes show good agreement between PIV and CFD, and 3D flow patterns show good similarity between PC-MRI and CFD. CONCLUSIONS: These findings give confidence to future haemodynamic studies using CFD technology. For the first time, the morphological inconsistency between the PCMRI model and others is found to affect the measurement of local flow patterns.

  38. What does computational fluid dynamics tell us about intracranial aneurysms? A meta-analysis and critical review. 国際誌 査読有り

    Khalid M Saqr, Sherif Rashad, Simon Tupin, Kuniyasu Niizuma, Tamer Hassan, Teiji Tominaga, Makoto Ohta

    Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism 40 (5) 1021-1039 2020年5月

    DOI: 10.1177/0271678X19854640  

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    Despite the plethora of published studies on intracranial aneurysms (IAs) hemodynamic using computational fluid dynamics (CFD), limited progress has been made towards understanding the complex physics and biology underlying IA pathophysiology. Guided by 1733 published papers, we review and discuss the contemporary IA hemodynamics paradigm established through two decades of IA CFD simulations. We have traced the historical origins of simplified CFD models which impede the progress of comprehending IA pathology. We also delve into the debate concerning the Newtonian fluid assumption used to represent blood flow computationally. We evidently demonstrate that the Newtonian assumption, used in almost 90% of studies, might be insufficient to describe IA hemodynamics. In addition, some fundamental properties of the Navier-Stokes equation are revisited in supplementary material to highlight some widely spread misconceptions regarding wall shear stress (WSS) and its derivatives. Conclusively, our study draws a roadmap for next-generation IA CFD models to help researchers investigate the pathophysiology of IAs.

  39. A Hemodynamic-Based Evaluation of Applying Different Types of Coronary Artery Bypass Grafts to Coronary Artery Aneurysms

    Wang, H., Wang, H., Anzai, H., Liu, Y., Qiao, A., Xie, J., Ohta, M., Ohta, M., Ohta, M.

    Complexity 2020 2020年

    出版者・発行元:WILEY-HINDAWI

    DOI: 10.1155/2020/9359340  

    ISSN:1076-2787

    eISSN:1099-0526

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    Coronary artery bypass grafts (CABGs), including saphenous vein grafts (SVGs) or left internal mammary artery (LIMA) grafts, are recently applied to treat coronary artery aneurysm (CAA). Surgical outcomes are considered to be related to surgical strategies (types of the bypass graft and whether CAA ligated or not) and the size of the CAA (usually characterized by diameter). However, the understanding of the relationship between the surgical outcomes and the abovementioned factors is limited. Previous studies related to CABG treatments have shown hemodynamic studies could help evaluate surgical outcomes through graft mass flow rate, wall shear stress (WSS), and oscillatory shear index (OSI). It is believed that the hemodynamic study of applying CABGs to CAA, which is not studied yet, could help us understand the different CABG surgeries. The aim of the study was to evaluate the hemodynamic differences among different surgical methods. To do this, eight three-dimensional models were constructed, representing application of SVGs and LIMA grafts to CAAs (whether ligated or not) with diameters two, three, and five times the normal diameter, to perform computational fluid dynamics (CFD) simulation. The lumped-parameter model (LPM) was coupled to the boundary of the 3D models which increase the complexity of the simulation, but it can ensure the stability of the simulation boundary conditions. The results show that SVG (no matter whether ligated or not) hemodynamic characteristics are positive, with an average high graft mass flow rate of 70 ml/min, an average WSS of 0.479 Pa, and a low OSI of 0.001. LIMA with CAA ligation has the same characteristics with higher WSS (average 1.701 Pa). The hemodynamic characteristics of LIMA without CAA ligation are negative, including high reverse mass flow rate and high OSI (0.367). The results indicate that the surgical outcomes of LIMA with CAA ligation are likely to be the best among these models. The surgical outcomes of LIMA without CAA ligation seem to be undesirable due to the high reverse mass flow and high OSI. The CAA diameter may not have a significant effect on surgical outcomes.

  40. Development of a stereo dip-coating system for fabrication of tube-shaped blood vessel models 国際誌

    Shimizu, Y., Tupin, S., Kiyomitsu, C., Kitamura, K., Takashima, K., Ohta, M.

    Scientific Reports 10 (1) 6929-6929 2020年

    出版者・発行元:Springer Science and Business Media {LLC}

    DOI: 10.1038/s41598-020-63718-w  

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    Tube-shaped blood vessel models that mimic their geometries and mechanical properties can deliver reliable and realistic behavioral information such as deformation and rupture during procedures such as insertion of medical devices. Thickness of vessel walls is an important parameter for fabricating the blood vessel models owing to their strong influence on the model behavior, especially during deformation. The dip-coating method is used to fabricate blood vessel models; however, non-uniform wall thicknesses are observed using this method. This study aimed at finding the characteristics of stereo "angular control dip-coating" (ACDC) system to develop a dip-coating system that can produce tubular models with uniformed wall thickness. The system developed here enables an observation of the substrate behavior from two different views. The conditions of dip-coating used in this study produce 1.36-1.82 mm in the maximum and 0.188-0.435 mm in minimum wall thickness and the fabricated walls cover the realistic range of carotid arterial dimensions. The characteristics of the ACDC system indicate that ACDC is effective for fabricating the uniform wall thickness particularly in the strong curved parts.

  41. Assessing porous media permeability in non-Darcy flow: A re-evaluation based on the Forchheimer equation 国際誌

    Tupin, S., Ohta, M.

    Materials 13 (11) 2535-2535 2020年

    出版者・発行元:{MDPI} {AG}

    DOI: 10.3390/ma13112535  

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    In a recent paper published in Materials (Castro et al., 2019), the permeability evaluation of triple periodic minimum surface samples was carried out experimentally. Darcy's law was used under unsuitable conditions, resulting in an underestimation of the results. In this comment, we highlight the problem and propose a new estimation of the permeability using the Forchheimer equation, which is better suited to the experimental conditions.

  42. Preliminary study of eye tracking to investigate the differences in gaze behaviors depending on the experience of neuroendovascular therapy. 国際誌

    Masaaki Shojima, Yoshihiro Okamoto, Kuniyasu Niizuma, Makoto Ohta, Osamu Ishikawa, Ayano Fujisawa, Hiroyuki Tsukihara, Nobuyuki Sakai, Teiji Tominaga

    Surgical neurology international 11 351-351 2020年

    DOI: 10.25259/SNI_543_2020  

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    Background: Neuroendovascular therapy is now the choice for the management of many neurovascular pathologies, and physicians with endovascular skills are in high demand. In addition to the traditional method of practicing hand movements to learn skills, a new strategy of practicing eye movements to learn skills is also attracting attention. This preliminary study explored the differences in gaze behavior depending on experience with endovascular procedures to be facilitated in future skill training in neuroendovascular therapy. Methods: Four physicians with experience of 3-412 neuroendovascular procedures wore eye-tracking devices during coil embolization of swine cervical arteries. Gaze metrics with direct correlations to the expertise of endovascular procedures were explored. Results: Gaze metrics with a positive direct correlation to experience included the proportion of fixation durations (PFD) in the screen area and the native images. Those with a negative direct correlation included the PFD in the off-screen area and the roadmap images and the average fixation durations in the off-screen and coil areas. During the parent artery occlusion procedure with detachable coils, more experienced operators preferred to look at native images rather than roadmap images and that less experienced operators tended to look down at their hands more frequently. Conclusion: This preliminary study demonstrated the feasibility of eye tracking to identify the differences in gaze behavior depending on the experience of endovascular procedures and may guide future eye-tracking studies in neuroendovascular therapy.

  43. Endothelial cell distributions and migration under conditions of flow shear stress around a stent wire. 国際誌 査読有り

    Hitomi Anzai, Tomohito Watanabe, Xiaobo Han, Narendra Kurnia Putra, Zi Wang, Hisatoshi Kobayashi, Makoto Ohta

    Technology and health care : official journal of the European Society for Engineering and Medicine 28 (4) 345-354 2020年

    DOI: 10.3233/THC-191911  

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    BACKGROUND: Blood vessels are constantly exposed to flow-induced stresses, and endothelial cells (ECs) respond to these stresses in various ways. OBJECTIVE: In order to facilitate endothelialization after endovascular implantation, cell behaviors around a metallic wire using a flow circulation system are observed. METHODS: A parallel flow chamber was designed to reproduce constant shear stresses (SSs) on cell surfaces and to examine the effects of a straight bare metal wire on cell monolayers. Cells were then exposed to flow for 24 h under SS conditions of 1, 2, and 3 Pa. Subsequently, cell distributions were observed on the plate of the flow chamber and on the surface of the bare metal wire. Flow fields inside the flow chamber were analyzed using computational fluid dynamics under each SS condition. RESULTS: After 24 h, ECs on the bottom plate were concentrated toward the area of flow reattachment. The matching of higher cell density and CFD result suggests that flow-induced stimuli have an influence on EC distributions. CONCLUSION: Typical cell concentration occurs on dish plate along the vortexes, which produces large changes in SSs on cell layer.

  44. 脳動脈瘤コイル留置のシミュレーション 手法と応用例

    高嶋 一登, 当麻 直樹, 太田 信, 森 浩二

    脳血管内治療 4 (Suppl.) S19-S19 2019年11月

    出版者・発行元:(NPO)日本脳神経血管内治療学会

    ISSN:2423-9119

    eISSN:2424-1709

  45. 脳動脈瘤コイル留置のシミュレーション 目的と課題

    当麻 直樹, 高嶋 一登, 太田 信, 森 浩二

    脳血管内治療 4 (Suppl.) S19-S19 2019年11月

    出版者・発行元:(NPO)日本脳神経血管内治療学会

    ISSN:2423-9119

    eISSN:2424-1709

  46. Pulse-Wave-Pattern Classification with a Convolutional Neural Network. 国際誌 査読有り

    Gaoyang Li, Kazuhiro Watanabe, Hitomi Anzai, Xiaorui Song, Aike Qiao, Makoto Ohta

    Scientific reports 9 (1) 14930-14930 2019年10月17日

    出版者・発行元:Springer Science and Business Media {LLC}

    DOI: 10.1038/s41598-019-51334-2  

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    Owing to the diversity of pulse-wave morphology, pulse-based diagnosis is difficult, especially pulse-wave-pattern classification (PWPC). A powerful method for PWPC is a convolutional neural network (CNN). It outperforms conventional methods in pattern classification due to extracting informative abstraction and features. For previous PWPC criteria, the relationship between pulse and disease types is not clear. In order to improve the clinical practicability, there is a need for a CNN model to find the one-to-one correspondence between pulse pattern and disease categories. In this study, five cardiovascular diseases (CVD) and complications were extracted from medical records as classification criteria to build pulse data set 1. Four physiological parameters closely related to the selected diseases were also extracted as classification criteria to build data set 2. An optimized CNN model with stronger feature extraction capability for pulse signals was proposed, which achieved PWPC with 95% accuracy in data set 1 and 89% accuracy in data set 2. It demonstrated that pulse waves are the result of multiple physiological parameters. There are limitations when using a single physiological parameter to characterise the overall pulse pattern. The proposed CNN model can achieve high accuracy of PWPC while using CVD and complication categories as classification criteria.

  47. 脳動脈瘤コイル塞栓術における術者の視線計測

    岡本 吉弘, 庄島 正明, 新妻 邦泰, 太田 信, 植松 美幸, 迫田 秀行, 配島 由二

    人工臓器 48 (2) S-224 2019年10月

    出版者・発行元:(一社)日本人工臓器学会

    ISSN:0300-0818

    eISSN:1883-6097

  48. Effect of a notch at the distal end of a microcatheter on vein deformation in segmental adrenal venous sampling: a preliminary study using computational fluid dynamics. 国際誌 査読有り

    Tomo Kinoshita, Kazumasa Seiji, Narendra Kurnia Putra, Tomohito Watanabe, Sho Matsumoto, Makoto Ohta, Kei Takase

    Medical & biological engineering & computing 57 (7) 1425-1436 2019年7月

    DOI: 10.1007/s11517-019-01968-1  

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    This study aimed to evaluate the effect of a notch at the distal end of a microcatheter on vein deformation in segmental adrenal venous sampling. A three-dimensional fluid-structure interaction simulation was performed using commercial finite element software. A computational model of a vein with a catheter inserted into it was constructed. The outer and inner diameters of the vein were 0.9 mm and 0.6 mm, respectively, whereas those of the catheter were 0.6 mm and 0.5 mm, respectively. The velocity of the blood flow at the outlet was 85 mm/s. The pressure at the inlet was 0 Pa. The mesh consisted of approximately 660,000 elements. The effect of the number (0-4) and shape (no notch, 1/4 circular, 1/3 circular, semicircular, 2/3 circlecircular, and 3/4 circular) of the notches at the distal end of the microcatheter on the vein deformation when a suction pressure was applied was evaluated. The venous wall displacement was the smallest with the one-notch catheter, followed by the four-notch catheter, and was the smallest with the catheter having 1/4-circular notches, followed by the one with 1/3-circular notches. In conclusion, microcatheters having one notch and 1/4-circular notches reduce vein deformation and lead to successful segmental adrenal venous sampling. Graphical abstract Comparing catheters having different notch shapes.

  49. 実体血管モデルを用いたコイルの接触面積・荷重の評価

    池田 雄太, 高嶋 一登, 葭仲 潔, 于 凱鴻, 太田 信, 森 浩二, 当麻 直樹, 鈴木 秀謙

    日本バイオレオロジー学会誌(B&R) 33 (2) 105-105 2019年6月

    出版者・発行元:(NPO)日本バイオレオロジー学会

    ISSN:0913-4778

    eISSN:2186-5663

  50. Evidence for non-Newtonian behavior of intracranial blood flow from Doppler ultrasonography measurements. 国際誌 査読有り

    Khalid M Saqr, Ossama Mansour, Simon Tupin, Tamer Hassan, Makoto Ohta

    Medical & biological engineering & computing 57 (5) 1029-1036 2019年5月

    DOI: 10.1007/s11517-018-1926-9  

    ISSN:0140-0118

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    Computational fluid dynamics (CFD) studies of intracranial hemodynamics often use Newtonian viscosity model to close the shear rate term in the Navier-Stokes equation. This is based on a commonly accepted hypothesis which state that non-Newtonian effects can be neglected in intracranial blood flow. This study aims to examine the validity of such hypothesis to guide future CFD studies of intracranial hemodynamics. Doppler ultrasonography (DUS) measurements of systolic and diastolic vessel diameter and blood velocity were conducted on 16 subjects (mean age 50.6). The measurements were conducted on the internal carotid (ICA), middle cerebral (MCA), and anterior communicating (AComA) arteries. Systolic and diastolic wall shear stress (WSS) values were calculated via the Hagen-Poiseuille exact solution using Newtonian and three different non-Newtonian models: namely Carreau, power-law and Herschel-Bulkley models. The Weissenberg-Rabinowitsch correction for blood shear-thinning viscosity was applied to the non-Newtonian models. The error percentage between the two sets of models was calculated and discussed. The Newtonian hypothesis was tested statistically and discussed using paired t tests. Significant differences (P < 0.0001) were found between the Newtonian and non-Newtonian WSS in ICA. In MCA and AComA, similar differences were found except in the systole and diastole for the Herschel-Bulkley and power-law models (P = 0.0669, P = 0.7298), respectively. The error between the Newtonian and non-Newtonian models ranged from - 27 to 30% (0.2 to 2.2 Pa). These values could affect the physical interpretation of IA CFD studies. Evidence suggests that the Newtonian assumption may be inappropriate to investigate intracranial hemodynamics. Graphical abstract The WSS estimation error resulting from using the Newtonian assumption compared to three non-Newtonian models for ICA, MCA, and AComA in systole and diastole conditions, based on TCCD measurements of 16 subjects. The error due to the Newtonian assumption ranged from 0.2 to 2.2 Pa (- 27 to 30%). These values could affect the physical interpretation of IA CFD studies.

  51. Influence of TGF-β1 expression in endothelial cells on smooth muscle cell phenotypes and MMP production under shear stress in a co-culture model. 国際誌 査読有り

    Han X, Sakamoto N, Tomita N, Meng H, Sato M, Ohta M

    Cytotechnology 71 (2) 489-496 2019年4月

    DOI: 10.1007/s10616-018-0268-7  

    ISSN:0920-9069

  52. Effects of Elasticity on Wall Shear Stress in Patient-Specific Aneurysm of Cerebral Artery 査読有り

    Ryuhei Yamaguchi, Taihei Kotani, Gaku Tanaka, Simon Tupin, Kahar Osman, Nadia Shaira Shafii, Ahmad Zahran, Md Khudzari, Kazuhiro Watanabe, Hitomi Anzai, Atsushi Saito, Makoto Ohta

    Journal of Flow Control, Measurement & Visualization 7 (2) 73-86 2019年2月

  53. Systematic review of hemodynamic discriminators for ruptured intracranial aneurysms 査読有り

    Yagi Takanobu, Okamoto Yoshihiro, Ohta Makoto, Nakamura Masanori, on behalf of the CFD-BIO study group, Ishida Fujimaro, Shojima Masaaki, Anzai Hitomi, Fujimura Souichiro, Sano Takanori, Shinozaki Shun, Yamanaka Yuuma, Yamamoto Yuuto

    Journal of Biorheology 33 (2) 53-64 2019年

    出版者・発行元:特定非営利活動法人 日本バイオレオロジー学会

    DOI: 10.17106/jbr.33.53  

    ISSN:1867-0466

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    <p>Researchers have aimed to identify unruptured intracranial aneurysms at a higher risk of rupture during follow-up for a long time. Computational fluid dynamics has been used widely to identify a hemodynamic discriminator between ruptured and unruptured aneurysms. However, this method has yet to reach a consensus between groups, which may be due, in part, to the significant degrees of freedom in hemodynamic indexes and computational workflows. The present review aims to characterize the degree of association between ruptured aneurysms and hemodynamic indexes, as well as the degree of variability between groups. A PubMed search identified 588 relevant studies. Thirteen met our criteria, yielding a total of 3,692 aneurysms. The definition of hemodynamic indexes were first carefully assessed and then classified accordingly. The variability of hemodynamic indexes between groups displayed a significant index-dependent nature. Normalizing hemodynamic indexes was an effective measure of reducing variability. Hemodynamic indexes were evaluated for <i>associability</i> and <i>quantifiability</i>. Overall, in an attempt to advance the diagnostic performance of hemodynamic indexes, these results shed light on the poor ability to interpret hemodynamic states pathologically. Future studies should incorporate the pathological significance of hemodynamic states into the design of hemodynamic indexes.</p>

  54. バイオニックヒューマノイド―血管モデル―血管モデルの現状と方向性 査読有り

    太田信, 清水康智, 于凱鴻, 吉田洋, 益田泰輔, 庄島正明, 松永忠雄, Simon Tupin, 芳賀洋一, 新井史人

    システム/制御/情報 63 (10) 415-419 2019年

  55. The effect of contact force during radiofrequency catheter ablation using a vibrating catheter: New cooling method for catheter ablation. 国際誌 査読有り

    Kaihong Yu, Tetsui Yamashita, Shigeaki Shingyochi, Kazuo Matsumoto, Atsuki Komiya, Makoto Ohta

    Technology and health care : official journal of the European Society for Engineering and Medicine 27 (6) 589-601 2019年

    DOI: 10.3233/THC-191639  

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    BACKGROUND: A new cooling method is proposed for preventing electrode-tissue overheating during cardiac catheter ablation using a vibrating catheter. Previous work has shown that vibration that results from increased flow velocity around the catheter can have a cooling effect on the electrode. OBJECTIVE: Contact force has been shown to be an important factor that affects cooling and lesion formation, because contact force determines the ratio of power delivery between blood and tissue. In this study, the effect of contact force on electrode cooling and tissue heating was investigated during the operation of an electrode cooled by vibration. METHODS: Using PVA-H or myocardium ablation tissue models under conditions of no flow, electrode and tissue temperatures and lesion sizes were measured at various vibrational frequencies and contact force conditions. RESULTS: The experiments showed that the catheter vibration still decreases the electrode temperature over a contact force range of 2-30 gf. The lesion size was increased with increasing contact force at each vibrational frequency. CONCLUSIONS: Increasing contact force can increase lesion size with cooling by vibration remaining effective.

  56. Multiobjective design optimization of stent geometry with wall deformation for triangular and rectangular struts. 国際誌 査読有り

    Narendra Kurnia Putra, Pramudita Satria Palar, Hitomi Anzai, Koji Shimoyama, Makoto Ohta

    Medical & biological engineering & computing 57 (1) 15-26 2019年1月

    DOI: 10.1007/s11517-018-1864-6  

    ISSN:0140-0118

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    The stent geometrical design (e.g., inter-strut gap, length, and strut cross-section) is responsible for stent-vessel contact problems and changes in the blood flow. These changes are crucial for causing some intravascular abnormalities such as vessel wall injury and restenosis. Therefore, structural optimization of stent design is necessary to find the optimal stent geometry design. In this study, we performed a multiobjective stent optimization for minimization of average stress and low wall shear stress ratio while considering the wall deformation in 3D flow simulations of triangular and rectangular struts. Surrogate-based optimization with Kriging method and expected hypervolume improvement (EHVI) are performed to construct the surrogate model map and find the best configuration of inter-strut gap (G) and side length (SL). In light of the results, G-SL configurations of 2.81-0.39 and 3.00-0.43 mm are suggested as the best configuration for rectangular and triangular struts, respectively. Moreover, considering the surrogate model and flow pattern conditions, we concluded that triangular struts work better to improve the intravascular hemodynamics. ᅟ Graphical abstract.

  57. Viscosity measurement of Xanthan-Poly(vinyl alcohol) mixture and its effect on the mechanical properties of the hydrogel for 3D modeling. 国際誌 査読有り

    Yasutomo Shimizu, Tadao Tanabe, Hiroshi Yoshida, Motohiro Kasuya, Tadao Matsunaga, Yoichi Haga, Kazue Kurihara, Makoto Ohta

    Scientific reports 8 (1) 16538-16538 2018年11月8日

    DOI: 10.1038/s41598-018-34986-4  

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    Biomodels made of poly(vinyl alcohol) (PVA) are demanded because they can represent the geometries and mechanical properties of human tissues realistically. Injecting and molding, commonly used in three-dimensional (3D) modeling, help to represent the blood vessels accurately. However, these techniques sometimes require higher pressures than the upper pressure limit of the dispensers for pouring in high viscosity materials; the material viscosity should therefore be lower. Moreover, the mechanical properties of the biomodels should be reproduced. This study proposes a PVA solution through the addition of xanthan gum (XG) for 3D modeling, which lowers liquid viscosity while maintaining the mechanical properties of biomodels. XG is known to facilitate the achievement of non-Newtonian fluidity; however, the effects of XG on a PVA solution and PVA hydrogel (PVA-H) are not confirmed. The viscosity measurement using 15 wt% PVA with XG solution (PVA/XG) shows that it will provide easier pouring than 17 wt% PVA solution. The tensile test using the PVA-H of PVA(15 wt%)/XG(0.2 wt%) reveals that the gel is comparable in Young's modulus to 17 wt% PVA-H. X-ray diffraction shows the crystalline structures of the PVA/XG gel and PVA-H are identical. Thus, this PVA/XG would be useful for fabricating biomodels using injection molding techniques.

  58. Numerical simulation of aneurysmal haemodynamics with calibrated porous-medium models of flow-diverting stents. 国際誌 査読有り

    Yujie Li, Mingzi Zhang, David I Verrelli, Winston Chong, Makoto Ohta, Yi Qian

    Journal of biomechanics 80 88-94 2018年10月26日

    DOI: 10.1016/j.jbiomech.2018.08.026  

    ISSN:0021-9290

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    Modelling flow-diverting (FD) stents as porous media (PM) markedly improves the efficiency of computational fluid dynamics (CFD) simulations in the study of intracranial aneurysm treatment. Nonetheless, the parameters of PM models adopted for simulations up until now were rarely calibrated to match the represented FD structure. We therefore sought to evaluate the PM parameters for a representative variety of commercially available stents, so characterising the flow-diversion behaviours of different FD devices on the market. We generated fully-resolved geometries for treatments using PED, Silk+, FRED, and dual PED stents. We then correspondingly derived the calibrated PM parameters-permeability (k) and inertial resistance factor (C2)-for each stent design from CFD simulations, to ensure the calibrated PM model has identical flow resistance to the FD stent it represents. With each of the calibrated PM models respectively deployed in two aneurysms, we studied the flow-diversion effects of these stent configurations. This work for the first time reported several sets of parameters for PM models, which is vital to address the current knowledge gap and rectify the errors in PM model simulations, thereby setting right the modelling protocol for future studies using PM models. The flow resistance parameters were strongly affected by porosity and effective thickness of the commercial stents, and thus accounted for in the PM models. Flow simulations using the PM stent models revealed differences in aneurysmal mass flowrate (MFR) and energy loss (EL) between various stent designs. This study improves the practicability of FD simulation by using calibrated PM models, providing an individualised method with improved simulation efficiency and accuracy.

  59. Structural Design and Numerical Analysis of a Novel Biodegradable Zinc Alloy Stent

    Kun Peng, Aike Qiao, Makoto Ohta, Narendra Kurnia Putra, Xinyang Cui, Yongliang Mu, Hitomi Anzai

    CMES-COMPUTER MODELING IN ENGINEERING & SCIENCES 117 (1) 17-28 2018年10月

    出版者・発行元:TECH SCIENCE PRESS

    DOI: 10.31614/cmes.2018.04113  

    ISSN:1526-1492

    eISSN:1526-1506

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    Biodegradable zinc alloy stents are a prospective solution for complications caused by the incompatibility between artery and permanent stents. However, insufficient scaffolding has limited the clinical application of biodegradable zinc alloy stents. Therefore, in this study, a new stent concept was designed to improve the scaffolding. The mechanical performances of the new and a traditional design stent were investigated and compared using finite element analysis (FEA). The new and traditional design stent were expanded to the intended radial displacement of 0.24 mm under the expansion pressure of 0.58 MPa and 0.45 MPa, respectively. Then, a pressure load of 0.35 MPa was exerted on the outer surfaces of the two stents to compress them. The results showed that the radial recoiling ratio were 45.3% and 83.3% for the new and the traditional stent, respectively. The simulations demonstrate that the biodegradable zinc alloy stent offers enhanced support because of the new structural design. This study implies that biodegradable zinc alloy stent can be a new competitive intervention device for the future clinical cardiovascular application.

  60. Computational Fluid Dynamics Analysis to Predict Endothelial Cells Migration During Flow Exposure Experiment With Placement of Two Stent Wires. 国際誌 査読有り

    Narendra Kurnia Putra, Zi Wang, Hitomi Anzai, Makoto Ohta

    Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual International Conference 2018 5454-5457 2018年7月

    DOI: 10.1109/EMBC.2018.8513517  

    ISSN:1557-170X

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    Stent deployment is currently used for many cardiovascular treatments. During its application, the presence of the stent inside the blood vessel will indeed cause some change in both flow environment and also vessel wall's cellular conditions. This research intends to learn about the flow phenomenon of how vessel wall endothelial cells (ECs) react to the presence of stent wires within a microfluidic flow chamber environment. Computational fluid dynamics (CFD) simulation analysis of the microfluidic flow chamber system has been performed for observing the hemodynamics phenomena in the chamber. Moreover, CFD method also can be beneficial as a planning step for a successful experimental study. We found that under the two wires configurations, high wall shear stress (WSS) area is developed on the downstream side of the wires. Based on the analysis of WSS and WSS gradients (WSSG) conditions, ECs morphological change and migration are likely to occur some specific area.

  61. Reproduction method for dried biomodels composed of poly (vinyl alcohol) hydrogels. 国際誌 査読有り

    Yasutomo Shimizu, Narendra Kurnia Putra, Makoto Ohta

    Scientific reports 8 (1) 5754-5754 2018年4月10日

    DOI: 10.1038/s41598-018-24235-z  

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    Models mimicking the realistic geometries and mechanical properties of human tissue are requiring ever-better materials. Biomodels made of poly (vinyl alcohol) are particularly in demand, as they can be used to realistically reproduce the characteristics of blood vessels. The reproducibility of biomodels can be altered due to dehydration that is observed after long periods of usage. In order to improve their usability, one should consider the method used to reproduce them; however, few studies have reported a method reproduce biomodels. This study proposes a novel reproduction method for biomodels that allows them to quickly and easily reproduce their geometric and mechanical properties. Specimens of the dried biomodels were reformed through immersion in temperature-controlled water. Our results show that water at 35 °C can be effective to reproduce both the geometric and mechanical properties of the specimens. X-ray diffraction (XRD) measurements revealed that water immersion can reform the crystal structure of the pre-dried specimens, and images obtained using micro-computed tomography acquisition show that the geometry of the specimens can be reformed by water immersion without introducing any defects. These results indicate that the proposed method can lead to high reproducibility of both the original geometric and mechanical properties of the dried biomodels.

  62. Biomodel of Hard Tissue for Dynamic Mechanical Testing of Medical Devices 国際共著

    Makoto Ohta, Dominik Huesener, Yuta Muramoto, Simon Tupin

    The Reports of the Institute of Fluid Science, Tohoku University 29 11-20 2018年2月

  63. 畳み込みニューラルネットワークに基づくアテローム性動脈硬化症患者のパルスパターン認識

    Gaoyang Li, 安西 眸, 渡邉 和浩, Aike Qiao, 太田 信

    バイオフロンティア講演会講演論文集 2018.29 2C11 2018年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebiofro.2018.29.2c11   10.1038/s41598-019-51334-2_references_DOI_DGABgnXW2V9ZPOSKNTUf6jSoCY6  

    eISSN:2424-2810

  64. 冠動脈瘤治療における血流の数値流体力学解析

    安西 眸, 太田 信

    年次大会 2018 J0210303 2018年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmemecj.2018.j0210303  

    eISSN:2424-2667

  65. Research on arterial stiffness status in type 2 diabetic patients based on pulse waveform characteristics

    Li, G., Song, X., Qiao, A., Ohta, M.

    CMES - Computer Modeling in Engineering and Sciences 117 (2) 2018年

    DOI: 10.31614/cmes.2018.04100  

  66. EXPERIMENTAL ANALYSIS FOR THE ANISOTROPIC FLOWS IN CANCELLOUS BONE 査読有り

    Ito, Makoto, Tupin, Simon, Anzai, Hitomi, Suzuki, Anna, Ohta, Makoto, ASME

    Proceedings of the Asme International Mechanical Engineering Congress and Exposition, 2017, Vol 3 2018年

  67. Effects of Pulsatile Inlet Conditions on the Hemodynamic Conditions of Stent with Deformed Wall Simulation 査読有り

    Narendra Kurnia Putra, Hitomi Anzai, Makoto Ohta

    Proceedings of the 5th international Conference on Instrumentation, Communications, Information Technology and Biomedical Engineering (ICICI-BME 2017) 57-61 2017年11月6日

    出版者・発行元:None

    ISSN:2158-0456

  68. Stent design optimization based on kriging surrogate model under deformed vessel wall: Pulsatile inlet flow 査読有り

    Narendra Kurnia Putra, Pramudita Satria Palar, Hitomi Anzai, Koji Shimoyama, Makoto Ohta

    Proceedings of the 2017 5th International Conference on Instrumentation, Control, and Automation, ICA 2017 172-176 2017年10月13日

    出版者・発行元:Institute of Electrical and Electronics Engineers Inc.

    DOI: 10.1109/ICA.2017.8068435  

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    The cardiovascular stent is one of the medical devices which has been commonly used for curing many vascular diseases. Nowadays, research on many aspects of stent development has been conducted to improve the device's efficacy. Mechanical and flow dynamics analysis on stent performance are useful to understand the impact of the device deployment. Many assumptions have been applied for constructing the stent simulation model including the blood vessel wall condition and its inlet flow conditions. Recently, common assumptions of the stent simulation model are mainly worked under the assumption of rigid wall condition and steady or pulsatile inlet flow. These different assumptions may lead to different simulation results. These differences may also affect the further analysis such as optimization process. This research tries to investigate the pulsatile effect on the stent optimization results based on computational simulation with wall deformation. Comparison with the previous optimization with a steady flow was conducted to find out about the differences between the two conditions. We found that the difference in optimization results from both inflow conditions is insignificant.

  69. In search for a better stent: Surrogate based multi-objective optimization of stent design under influence of vessel wall deformation. 国際誌 査読有り

    Narendra Kurnia Putra, Pramudita Satria Palar, Hitomi Anzai, Koji Shimoyama, Makoto Ohta

    Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual International Conference 2017 1344-1347 2017年7月

    DOI: 10.1109/EMBC.2017.8037081  

    ISSN:1557-170X

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    Stenting is known as one of the main treatment procedure for some intravascular abnormalities such as stenosis and aneurysm. In recent years, stent optimization has been conducted by several research groups in order to increase its treatment efficacy. If we can observe post-deployment behavior on the blood vessel with respect to different stent designs, this observation will be useful in the design process. Kriging surrogate model based on fluid flow simulation on a deformed vessel wall was developed in order to observe this behavior. Multi-objectives optimization was performed with configurations of gap and size as design variables. In this research, percentage of low wall shear stress (WSS) area and average mechanical stress along the deployment area were set as the objective functions. We can recommend that strut with medium size around 100 - 250 micron with a relatively big inter-strut gap is suitable for achieving the optimize criteria. This is because on this range, acceptable optimized value of both objectives functions are successfully obtained.

  70. Applying computer simulation to the design of flow-diversion treatment for intracranial aneurysms. 国際誌 査読有り

    Mingzi Zhang, Yujie Li, David I Verrelli, Winston Chong, Makoto Ohta, Yi Qian

    Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual International Conference 2017 3385-3388 2017年7月

    DOI: 10.1109/EMBC.2017.8037582  

    ISSN:1557-170X

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    Although flow-diversion (FD) treatment has been proven to be able to induce intracranial aneurysm (IA) occlusion, clinical follow-ups reported that a number of patients may still suffer from delayed IA rupture or incomplete aneurysm occlusion post-treatment. Complete aneurysm occlusion is believed to be associated with favourable haemodynamic alteration post-treatment, which may be greatly affected by the selection of device size and quantity, as well as the FD deployment procedure. However, clinicians have to choose and deploy the FD relying on their experience, since no post-stenting haemodynamic information is generally available to them prior to a specific treatment. In this study, using a virtual FD deployment technique and computational fluid dynamics method, we demonstrate and compare the haemodynamic changes after virtual FD treatments using a variety of prospective treating strategies.

  71. Sensitivity study on modelling a flow-diverting stent as a porous medium using computational fluid dynamics. 国際誌 査読有り

    Yujie Li, Mingzi Zhang, David I Verrelli, William Yang, Winston Chong, Makoto Ohta, Yi Qian

    Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual International Conference 2017 3389-3392 2017年7月

    DOI: 10.1109/EMBC.2017.8037583  

    ISSN:1557-170X

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    The flow-diverting (FD) stent has become a commonly used endovascular device to treat cerebral aneurysms. This discourages blood from entering the aneurysm, thereby reducing the likelihood of aneurysm rupture. Using computational fluid dynamics (CFD) to simulate the aneurysmal haemodynamics after FD treatment could help clinicians predict the stent effectiveness prior to the real procedure in the patient. As an alternative to modelling the stent as a fine wire mesh, modelling the FD stent as a porous medium was established to save computational time, and has also been proved capable of predicting the same haemodynamics as obtained using the real FD stent geometry. The flow resistance effect of a porous-medium stent may differ with respect to its morphology or permeability; however, the flow resistance effect after adjusting these parameters had not been clarified. In this study, we analysed the haemodynamic changes caused by alterations of porous-medium thickness and permeability, thereby providing future porous-medium stent simulations with important information on the respective parametric sensitivities. We found significant sensitivity to permeability. Results were insensitive to thickness when permeability was adjusted beforehand to compensate. We also compared our results with observations from an in-vitro model, and found good agreement. This supports adoption of porous-medium models in future work.

  72. Comparative Study between Different Strut’s Cross Section Shape on Minimizing Low Wall Shear Stress along Stent Vicinity via Surrogate-based Optimization 査読有り

    Narendra Kurnia Putra, Pramudita Satria Palar, Hitomi Anzai, Koji Shimoyama, Makoto Ohta

    12th World Congress of Structural and Multidisciplinary Optimisation 2017年6月9日

  73. Haemodynamic effects of stent diameter and compaction ratio on flow-diversion treatment of intracranial aneurysms: A numerical study of a successful and an unsuccessful case 国際誌 査読有り

    Mingzi Zhang, Yujie Li, Xi Zhao, David I. Verrelli, Winston Chong, Makoto Ohta, Yi Qian

    JOURNAL OF BIOMECHANICS 58 179-186 2017年6月

    出版者・発行元:ELSEVIER SCI LTD

    DOI: 10.1016/j.jbiomech.2017.05.001  

    ISSN:0021-9290

    eISSN:1873-2380

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    Background: Compacting a flow-diverting (FD) stent is an emerging technique to create a denser configuration of wires across the aneurysm ostium. However, quantitative analyses of post-stenting haemodynamics affected by the compaction level of different stent sizes remain inconclusive.Objective: To compare the aneurysmal haemodynamic alterations after virtual FD treatments with different device diameters at different compaction ratios.Methods: We virtually implanted three sizes of FD stent, with each size deployed at four compaction ratios, into two patient aneurysms previously treated with the Silk + FD-one successful case and the other unsuccessful. Wire configurations of the FD in the 24 treatment scenarios were examined, and aneurysmal haemodynamic alterations were resolved by computational fluid dynamics (CFD) simulations. We investigated the aneurysmal flow patterns, aneurysmal average velocity (AAV), mass flowrate (MF), and energy loss (EL) in each scenario.Results: Compactions of the stent in the successful case resulted in a greater metal coverage rate than that achieved in the unsuccessful one. A 25% increment in compaction ratio further decreased the AAV (12%), MF (11%), and EL (9%) in both cases (average values). The averaged maximum differences attributable to device size were 10% (AAV), 8% (MF), and 9% (EL).Conclusions: Both stent size and compaction level could markedly affect the FD treatment outcomes. It is therefore important to individualise the treatment plan by selecting the optimal stent size and deployment procedure. CFD simulation can be used to investigate the treatment outcomes, thereby assisting doctors in choosing a favourable treatment plan. (C) 2017 Elsevier Ltd. All rights reserved.

  74. 光ファイバ圧力センサを搭載した血管モデルによる脳動脈瘤コイル塞栓術評価システム

    Osaki Soyaka, Matsunaga Tadao, Shimizu Yasutomo, Shouzima Masaaki, Yoshida Hiroshi, Tsuruoka Noriko, Ohta Makoto, Haga Yoichi

    生体医工学 55 (4) 287-287 2017年

    出版者・発行元:公益社団法人 日本生体医工学会

    DOI: 10.11239/jsmbe.55Annual.287  

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    <p>近年、脳動脈瘤の治療において血管内治療の1つであるコイル塞栓術が広く施行されている.しかし、この手法において瘤内でコイルが偏って留置された場合や,ネック部分の血流が充分に妨げられない場合,治療の効果が充分に得られないことがあり,コイル塞栓術の効果を定量的に評価することが重要と考えられる.ポリビニルアルコールハイドロゲル(PVA-H)で作製した脳動脈瘤付き血管モデルの動脈瘤内部と周辺の血管内における局所の圧力を多点計測できるようにし,塞栓コイル留置前後の圧変化を計測した.光ファイバを利用した極細径圧力センサを2本,動脈瘤モデルの外側から動脈瘤内に刺入,固定し,動脈瘤周辺血管の上流側と下流側にそれぞれ市販の圧センサを接続した.動脈瘤内の塞栓コイルを増やしながら圧を計測することで,動脈瘤内圧の変化を計測することができた.(356文字)</p>

  75. Development of endovascular treatment environment for medical training and simulation using coiling

    Shimizu Yasutomo, Tupin Simon, Yu Kaihong, Osaki Soyoka, Yoshida Hiroshi, Shojima Masaaki, Matsunaga Tadao, Haga Yoichi, Ohta Makoto

    生体医工学 55 (4) 288-288 2017年

    出版者・発行元:公益社団法人 日本生体医工学会

    DOI: 10.11239/jsmbe.55Annual.288  

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    <p>Intravascular treatment is recognized as one of the most difficult skills to acquire for medical doctors and realistic in vitro training systems for endovascular treatment are increasingly demanded these days. Vessel model is a major part to construct the system with strong requirements of the reproducibility of both mechanical properties and haptic sense during catheter operation. In this study, the condition to fabricate realistic models and the training system imitating the environment of intravascular treatment were established and 4-coil occlusion in the aneurysmal model was performed by a skilled medical doctor. The coils are successfully inserted into the aneurysm and the doctor evaluates haptic sense during the operation is similar to realistic situations. The experimental result and the doctor's evaluation indicate the new developed system is beneficial to the training of intravascular treatment.</p>

  76. 評価グリッド法を用いた医者による血管モデルの評価構造の分析

    Yu Kaihong, Shimizu Yasutomo, Tupin Simon, Shojima Masaaki, Ohta Makoto

    生体医工学 55 (4) 286-286 2017年

    出版者・発行元:公益社団法人 日本生体医工学会

    DOI: 10.11239/jsmbe.55Annual.286  

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    <p>Recently, with the increased popularity of endovascular therapy, blood vessel model become more important owing to its practicality in skill training and new device evaluation. To develop the appropriate model, it's necessary to understand how doctors evaluate the model. In this research, a doctor in NeuroEndovascular therapy was interviewed to analyze his evaluation structure of blood vessel. During the test, the doctor was asked to evaluate three different blood vessel models made based on a same realistic geometry of cerebral artery by using catheter. A sensory test methodology called evaluation grid method was used to analyze the evaluation structure of the doctor. Our results suggest that, the evaluation of a blood vessel model by a doctor is made based on the sensation given by the model through the catheter, including the friction of the inner wall, the similarity of the shape, and the confidence obtained by using the model.</p>

  77. The influence of TGF-β1 from ECs on SMC MMP-2 Production under Shear Stress in a Co-Culture Model

    Han Xiaobo, Sakamoto Naoya, Tomita Noriko, Meng Hui, Sato Masaaki, Ohta Makoto

    生体医工学 55 (5) 414-414 2017年

    出版者・発行元:公益社団法人 日本生体医工学会

    DOI: 10.11239/jsmbe.55Annual.414  

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    <p>In the present study, the author constructed an EC-SMC co-culture model with SMCs 3D cultured in a collagen gel, and SMCs phenotype was controlled into a contractile state. Then, different magnitudes of shear stress (SS) were applied to the co-culture model and the results showed that a high SS of 10 Pa could induce higher matrix metalloproteinases (MMPs) productions from SMC in the co-culture model. As to understand ECs influence on SMC responses, TGF-β1 (Transforming growth factor beta 1) expression from ECs were suppressed by an SiRNA transfection method in the present study. Compared to different MMP-2 production levels under different SS in the normal co-culture model, SMCs showed same MMP-2 production level under all SS conditions in the co-culture model with transfected ECs. This result means that TGF-β1 expression from ECs could influence SMCs response to SS in a co-culture model.</p>

  78. Response Surface based Analysis to Improve the Intravascular Stent Design Performance on Optimizing Wall Shear Stress Conditions

    Putra Narendra Kurnia, Palar Pramudita Satria, Anzai Hitomi, Shimoyama Koji, Ohta Makoto

    生体医工学 55 (5) 415-415 2017年

    出版者・発行元:公益社団法人 日本生体医工学会

    DOI: 10.11239/jsmbe.55Annual.415  

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    <p>Restenosis is known as common problem during stent treatment. Stent optimization has been introduced to find the best design criteria in order to improve the endovascular treatment efficacy. Surrogate method is known as efficient method of optimization that has been built up from finite element method (FEM) simulation. Besides obtaining the optimized criteria, response surface plot which constructed by Kriging surrogate estimation process is also beneficial to study the behavior of design variables towards objective functions. In this study, we constructed the response surface map from stent design parameter configuration of strut size and inter-strut gap towards objective function. Our objective function is to minimizing the percentage of low wall shear stress area along deployment region. With this response surface, broad analysis on the stent performance can be clearly observed. More recommendations on how combinations between stent strut's size and gap should be designed are successfully obtained by this study.</p>

  79. Development of in-vitro experimental devices for in-situ evaluation of hemodynamic effects induced by endovascular devices and their deployment

    Tupin Simon, Anzai Hitomi, Ohta Makoto

    生体医工学 55 (5) 416-416 2017年

    出版者・発行元:公益社団法人 日本生体医工学会

    DOI: 10.11239/jsmbe.55Annual.416  

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    <p>Endovascular devices are medical devices inserted into the arteries in case of aneurysm. This minimally invasive treatment is preferred in case of aged patient. The number of commercially available device designs increased on the market but no data exist regarding direct comparisons of their performance, difficult to perform in vivo. The purpose of this research is to create in vitro experimental platforms allowing the study of the influence of those medical devices by monitoring the hemodynamic changes occurred during their deployments. Precise multi-scale evaluation of pressure and flow rate into the arteries surrounding the aneurysm are performed and synchronized to each step of the medical procedure. Further analysis are also conducted on the geometry of the deployed devices and flow pattern changes after deployment. As a proof of concept, studies of the treatment of an abdominal aortic aneurysm and an intracranial aneurysm are presented.</p>

  80. Applying Computer Simulation to the Design of Flow-diversion Treatment for Intracranial Aneurysms

    Mingzi Zhang, Yujie Li, David I. Verrelli, Winston Chong, Makoto Ohta, Yi Qian

    2017 39TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY (EMBC) 3385-3388 2017年

    出版者・発行元:IEEE

    ISSN:1094-687X

    詳細を見る 詳細を閉じる

    Although flow-diversion (FD) treatment has been proven to be able to induce intracranial aneurysm (IA) occlusion, clinical follow-ups reported that a number of patients may still suffer from delayed IA rupture or incomplete aneurysm occlusion post-treatment. Complete aneurysm occlusion is believed to be associated with favourable haemodynamic alteration post-treatment, which may be greatly affected by the selection of device size and quantity, as well as the FD deployment procedure. However, clinicians have to choose and deploy the FD relying on their experience, since no post-stenting haemodynamic information is generally available to them prior to a specific treatment. In this study, using a virtual FD deployment technique and computational fluid dynamics method, we demonstrate and compare the haemodynamic changes after virtual FD treatments using a variety of prospective treating strategies.

  81. Influence of shear stress on phenotype and MMP production of smooth muscle cells in a co-culture model 査読有り

    Xiaobo Han, Naoya Sakamoto, Noriko Tomita, Hui Meng, Masaaki Sato, Makoto Ohta

    Journal of Biorheology 31 (2) 50-56 2017年1月1日

    出版者・発行元:Japanese Society of Biorheology

    DOI: 10.17106/jbr.31.50  

    ISSN:1867-0474 1867-0466

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    BACKGROUND: High shear stress (SS) could affect vascular remodeling during initiation of cerebral aneurysms. However, the response of smooth muscle cells (SMCs) to high SS, which is related to blood vessel remodeling, are poorly understood. OBJECTIVE: We explored the effect of high SS on SMCs in an EC-SMC coculture model to investigate blood vessel remodeling during aneurysm formation. METHODS: SMCs were threedimensionally cultured in a collagen gel, with ECs cultured on a membrane filter above the SMCs. Then, the co-culture model was exposed to different SS of 0.2, 2, 6, and 10 Pa for 72 h. RESULTS: A physiological SS of 2 Pa maintained the expression of contractile proteins in SMCs, whereas lower or higher SS decreased the expression, suggesting a phenotypic change to a synthetic state. Furthermore, we found that a high SS of 10 Pa increased production of both matrix metalloproteinase (MMP) -2 and -9 from SMCs, which could induce destructive blood vessel remolding. CONCLUSIONS: High SS could change the SMC phenotype to a synthetic state and induce higher MMP production by SMCs in the co-culture model. These results may help to further elucidate blood vessel remodeling mechanisms under high SS conditions.

  82. Evaluation of the effect of catheter on the guidewire motion in a blood vessel model by physical and numerical simulations 査読有り

    Kazuto Takashima, Atomu Oike, Kiyoshi Yoshinaka, Kaihong Yu, Makoto Ohta, Koji Mori, Naoki Toma

    Journal of Biomechanical Science and Engineering 12 (4) 2017年

    出版者・発行元:Japan Society of Mechanical Engineers

    DOI: 10.1299/jbse.17-00181  

    ISSN:1880-9863

    詳細を見る 詳細を閉じる

    Various catheter simulators using a computer or blood vessel biomodels have been developed for training of medical students and young physicians. Moreover, we have developed a system to simulate a guidewire in blood vessels that uses both numerical analysis and experimental observation for the quantitative analysis of treatment technique, surgical planning, intra-operative assistance, and to facilitate the design of new guidewires. However, not limited to our group, there is a lack of studies evaluating the motions of both the guidewire and catheter and their interaction in a blood vessel. Therefore, in the present study, we modified our computer-based system and experimental apparatus to evaluate the catheter motion and compared both results. First, we added a mechanism to the experimental apparatus to move and evaluate the catheter in a poly (vinyl alcohol) hydrogel blood vessel model. Second, we added a new catheter model to the calculation. We subsequently evaluated the behaviors of the medical devices (the guidewire and the catheter) by measuring the three-dimensional position and the contact force between the medical devices and the vessel wall. Comparison of the calculation and experimental results showed that the trajectories and the contact forces of both the experimental and numerically analyzed medical devices had the same tendencies. By considering the flexibility of the catheter in both the experimental and numerical analysis methods, we could reproduce the phenomena seen in clinical situations, such as movement of the catheter during the insertion or removal of the guidewire, and movement of the guidewire during the insertion of the catheter.

  83. Blood vessel model equipped with ultrasound sensors for evaluation of intravascular treatment 査読有り

    Hiroshi Yoshida, Yasutomo Shimizu, Masaaki Shojima, Makoto Ohta, Tadao Matsunaga, Noriko Tsuruoka, Yoichi Haga

    Transactions of Japanese Society for Medical and Biological Engineering 55 (Proc) 544-546 2017年

    出版者・発行元:Japan Soc. of Med. Electronics and Biol. Engineering

    DOI: 10.11239/jsmbe.55Annual.544  

    ISSN:1347-443X 1881-4379

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    Intravascular surgery, such as coil embolization and stent placement, has been widely performed for treatment of cerebral aneurysms. Doctors must be skillful and sufficiently experienced to successfully manipulate and insert a guidewire and a catheter into the aneurysm via carotid and cerebral artery. Though blood vessel model is useful for training of the doctors in the field of the intravascular surgery, evaluation of doctor’s skill and efficacy of training is insufficient. In this study, an ultrasound sensor was fabricated and equipped in the cerebral blood vessel model to measure the displacement of the vessel wall that is contacted and pushed by a guidewire or a catheter. It is confirmed that the fabricated ultrasound sensor could measure the displacement of blood vessel wall by the inserted catheter.

  84. Ultrasound sensors installed in blood vessel model for intravascular surgery procedures. 査読有り

    Hiroshi Yoshida, Noriko Tsuruoka, Yasutomo Shimizu, Kaihong Yu, Makoto Ohta, Masaaki Shojima, Tadao Matsunaga, Yoichi Haga

    IEEE International Conference on Cyborg and Bionic Systems, CBS 2017, Beijing, China, October 17-19, 2017 289-292 2017年

    出版者・発行元:IEEE

    DOI: 10.1109/CBS.2017.8266117  

  85. Development of a blood vessel model with ultrasound sensors to quantify intravascular treatment skills. 査読有り

    Hiroshi Yoshida, Tadao Matsunaga, Yasutomo Shimizu, Masaaki Shojima, Kaihong Yu, Makoto Ohta, Noriko Tsuruoka, Yoichi Haga

    International Symposium on Micro-NanoMechatronics and Human Science, MHS 2017, Nagoya, Japan, December 3-6, 2017 1-4 2017年

    出版者・発行元:IEEE

    DOI: 10.1109/MHS.2017.8305199  

  86. Local internal pressure measurement system of cerebral aneurysm model using ultra-miniature fiber-optic pressure sensor. 査読有り

    Tadao Matsunaga, Akira Ito, Soyoka Osaki, Yasutomo Shimizu, Masaaki Shojima, Hiroshi Yoshida, Noriko Tsuruoka,Array, Makoto Ohta, Yoichi Haga

    International Symposium on Micro-NanoMechatronics and Human Science, MHS 2017, Nagoya, Japan, December 3-6, 2017 1-3 2017年

    出版者・発行元:IEEE

    DOI: 10.1109/MHS.2017.8305197  

  87. Multipoint pressure measurement in blood vessel model for evaluation of intravascular treatment of cerebral aneurysm using fiber-optic pressure sensors 査読有り

    Matsunaga, Tadao, Haga, Yoichi, Osaki, Soyoka, Shimizu, Yasutomo, Tupin, Simon, Ohta, Makoto, Shojima, Masaaki, Yoshida, Hiroshi, Tsuruoka, Noriko, IEEE

    2017 Ieee International Conference on Cyborg and Bionic Systems (Cbs) 2017年

  88. COMPUTATIONAL FLUID DYNAMICS ANALYSIS OF THE BONE MARROW IN CANCELLOUS BONE AS A NON-NEWTONIAN FLUID 査読有り

    Makoto Ohta, Wataru Sakuma, Toshio Nakayama, Hitomi Anzai, Makoto Ito, Katsuyuki Sado, Shuji Nakamura

    PROCEEDINGS OF THE ASME INTERNATIONAL MECHANICAL ENGINEERING CONGRESS AND EXPOSITION, 2016, VOL. 3 2016 2017年

    出版者・発行元:AMER SOC MECHANICAL ENGINEERS

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    Stem cells in the bone marrow (BM) are used as regenerative treatment for leukemia. They are usually harvested by puncturing the cancellous bone in the ilium of the donor with a needle. However, this process can cause severe burden to the donor because of its inefficiency; the bone may require 50-100 punctures to obtain enough stem cells. Various factors affect the volume of BM harvested, and their influence can be estimated by observing the flow in the cancellous bone. Recent computational fluid dynamics (CFD) analyses of BM with 3-D reconstruction of the cancellous bone have profiled flow velocity or wall shear stress (WSS) and have shown that some parts on the surface of the cancellous bone have higher WSS and that this high WSS may tear cells from the surface of the bone. CFD analysis may therefore help determining a method for efficient stem cell harvest. However, it is difficult to validate CFD using BM structure because of its porosity. To improve the accuracy of WSS and flow pattern calculations, blood characteristics should be incorporated as key factors and the effects of non-Newtonian flow and viscosity on the flow patterns evaluated. Therefore, the purpose of this study was to evaluate CFD analyses of BM in the cancellous bone based on flow where viscosity depended on the shear rate. BM from porcine ilium bones was extracted, and the viscosities of samples, with or without anti-clotting medications, were measured at various shear rates. 3-D reconstruction of the cancellous bone was performed using micro-CT after removing BM and fat from the bone. The resolution of the reconstruction was 11.7 mu m per pixel, which was sufficient to reconstruct the porous structure. The size of the bone sample was 2.5 x 2.5 x 3.5 mm. The number of mesh was approximately 4.3 million. CFD analyses were performed using 3-D reconstruction and viscosity profile at three pressure differences (5, 7, and 10 kPa). Constant pressure was applied in the outlet. The viscosity of BM could be divided into three shear rate ranges. The first corresponded with a shear rate over 100 1/s, where the viscosity was constant at less than 0.01 Pa.s. Transient curves were observed for shear rates 0.01-100 1/s. At lower shear rates, the viscosity was again constant, at over 10(5) Pa.s. These changes were higher than the changes in blood viscosity based on the shear rate. The CFD analyses showed that the results depended on the inlet pressure. When the pressure difference was 10 kPa, the viscosity change almost disappeared, and the velocity profile was similar to that of Newtonian flow. When the pressure difference was 5 or 7 kPa, changes in viscosity and completely changed flow patterns were observed. The WSS profile also changed with the velocity profile. Therefore, pressure can be a major factor in the velocity profile of BM in the cancellous bone. Effects of non-Newtonian flow on velocity and WSS profiles were observed under an appropriate pressure difference.

  89. Deformation of stenotic blood vessel model made from Poly (Vinyl Alcohol) Hydrogel by hydrostatic pressure 査読有り

    Yasutomo Shimizu, Lei Liu, Hiroyuki Kosukegawa, Kenichi Funamoto, Toshiyuki Hayase, Toshio Nakayama, Makoto Ohta

    PROCEEDINGS OF THE ASME INTERNATIONAL MECHANICAL ENGINEERING CONGRESS AND EXPOSITION, 2016, VOL. 3 2016 2017年

    出版者・発行元:AMER SOC MECHANICAL ENGINEERS

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    Vascular plaque deformation reduces blood flow, increases arterial embolism risk, and may lead to ischemic stroke. Plaque stiffness varies widely and is an important factor influencing both plaque and parent artery deformation. These geometric changes affect local hemodynamics, which impact plaque initiation influencing disease progression. However, most previous studies used non-elastic stenotic vessel models. For more realistic analysis, we constructed a stenosis model comprising an elastic poly (vinyl alcohol) hydrogel (PVA-H) parent artery and plaque of variable stiffness. Our previous study using this flexible model demonstrated substantial effects of hydrostatic pressure. Here ultrasonography was conducted under changing hydrostatic pressure to measure geometric changes at the narrowest cross section. PVA-H specimens were constructed with the stiffness of a hard lipid core, smooth muscle, and plaque, as estimated by tensile tests using 5, 12, and 15 wt% PVA, respectively. The change in cross-sectional aspect ratio (height/face length) at the narrowest site is largest (similar to 1.3) for the 5 wt% PVA-H plaque and smallest (similar to 1.2) for the 12 wt% PVA-H plaque. Stenotic artery deformation depends on both artery and plaque elasticity. Hydrostatic pressure has a substantial effect on both vessel and plaque geometries, which markedly alter blood flow.

  90. DEVELOPMENT OF THE WORKING FLUID WITH BLOOD VISCOSITY FOR EVALUATING ABLATION CATHETER IN IN VITRO SYSTEM 査読有り

    Kaihong Yu, Ren Takahashi, Makoto Ohta

    PROCEEDINGS OF THE ASME INTERNATIONAL MECHANICAL ENGINEERING CONGRESS AND EXPOSITION, 2016, VOL. 3 2016 2017年

    出版者・発行元:AMER SOC MECHANICAL ENGINEERS

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    The purpose of this study was to develop a working fluid with the proper viscosity to mimic blood flow to evaluate an ablation catheter. We proposed a working fluid that matches the blood viscosity, using glycerol-saline solution or xanthan gum (XG)saline solution. We compared the two solution mixtures at various concentrations (for glycerol-saline solution, 10%, 30%, and 50%; for XG-saline solution, 0.10%, 0.11%, 0.12%, and 0.13%) by measuring their temperature dependence on viscosity. To test the developed working fluids, RF ablations were performed with both solutions, and the flow around the catheter during ablation was observed by particle image velocimetry (PIV) method. In addition, to test the efficacy of the solution mixtures, myocardium was observed after it was soaked separately in the two solution mixtures. The viscosity of both kinds of solution mixtures increased at higher concentrations and decreased with increasing temperatures. At 37 degrees C, the viscosities of 50% glycerol-saline solution and 0.11%-0.13% XG-saline solution were 3-4 mPa.s, a value that is similar to the viscosity of blood. The upward flow resulting from heat convection by ablation was observed around the catheter in the PIV analysis using an in vitro model without flow. The solution mixture with the higher viscosity flowed at a lower velocity around the catheter, and the myocardium soaked in 50% glycerol -saline solution shrunk into a black and tough tissue. On the other hand, the myocardium soaked in XG-saline solution showed no change in color or shape. In conclusion, the XG-saline solution is a superior option for evaluating ablation catheters.

  91. FLOW SIMULATIONS TO ESTABLISH THE RELATIONSHIP BETWEEN THE INFLOW ZONE IN THE NECK OF A CEREBRAL ANEURYSM AND THE POSITIONS OF STRUTS 査読有り

    Kazuhiro Watanabe, Hitomi Anzai, Makoto Ohta

    PROCEEDINGS OF THE ASME INTERNATIONAL MECHANICAL ENGINEERING CONGRESS AND EXPOSITION, 2016, VOL. 3 2016 2017年

    出版者・発行元:AMER SOC MECHANICAL ENGINEERS

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    Flow-diverter (FD) stent implantation is an attractive treatment for cerebral aneurysms because of its low level of invasiveness. FD stent has a fine mesh structure, and the aim of FD implantation is to reduce the blood flow in an aneurysm by covering the aneurysm orifice. However, the fine mesh of the implant poses the risk of parent artery occlusion. One approach for avoiding this risk is to use a stent with a higher porosity. Previous studies have shown that placing a strut to disturb the inflow entering an aneurysm can promote a higher reduction in aneurysm flow. However, Hirabayashi et al. reported that a high-porosity stent can be sensitive to misdeployment in flow reduction. We hypothesized that a positioning error in flow reduction was sensitive to the relative position of the strut to the inflow configuration. In this study, we performed flow simulation to investigate the relationship between the inflow zone of the aneurysm neck and the positions of struts. Lattice Boltzmann (LB) flow simulation was performed to allow a comprehensive study of strut positions. Two rectangular solids were used as the strut model. Steady flow simulation was applied to models based on ideal and realistic three-dimensional (3D) aneurysm geometry, changing two strut positions along the neck plane. For both models, velocity boundaries were imposed on the inlet and a constant pressure boundary was imposed on the outlet. Average flow velocity in an aneurysm was calculated to evaluate the dependency of the flow reduction effect on the deployment position. We analyzed aneurysm flow using the following three strategies to observe the relationship between flow configuration, strut configuration, and flow reduction. Analysis A: Flow reduction rate (R-f) with one strut. A strut was moved from the proximal to the distal neck (perpendicular deployment) or from outside to inside (parallel deployment). Analysis B: R-f with two struts. One strut (strut A) was fixed in a specific position on the neck plane. The other (strut B) was moved along the neck plane in parallel to strut A. Analysis C: R-f with two struts. Strut B was located on the distal or inner side of strut A. The distance between the two struts was changed, and the two struts were moved along the neck plane while maintaining that distance. From the results of Analyses A and B, we confirmed a critical area in the inflow zone that maintained a high flow reduction regardless of the position of the second strut. The results of Analysis C confirmed that there were several distances between the struts at which flow reduction was almost constant. This constant reduction was maintained when one of the struts was located in the critical area, whereas the reduction was disturbed if both struts were located outside the area. These results suggest that the influence of positioning errors can be reduced by constantly placing at least one strut in a critical area, resulting in a high flow reduction. This may lead to optimal stent porosity for flow reduction and robustness of deployment.

  92. FLOW SIMULATIONS TO ESTABLISH THE RELATIONSHIP BETWEEN THE INFLOW ZONE IN THE NECK OF A CEREBRAL ANEURYSM AND THE POSITIONS OF STRUTS 査読有り

    Watanabe, Kazuhiro, Anzai, Hitomi, Ohta, Makoto, ASME

    Proceedings of the Asme International Mechanical Engineering Congress and Exposition, 2016, Vol. 3 2017年

  93. DEVELOPMENT OF THE WORKING FLUID WITH BLOOD VISCOSITY FOR EVALUATING ABLATION CATHETER IN IN VITRO SYSTEM 査読有り

    Yu, Kaihong, Takahashi, Ren, Ohta, Makoto, ASME

    Proceedings of the Asme International Mechanical Engineering Congress and Exposition, 2016, Vol. 3 2017年

  94. Development of a poly (vinyl alcohol) hydrogel phantom to allow physical measurement in ultrasonographic conditions: a model for scatter 査読有り

    Takahashi, Ren, Tamura, Kazuki, Yamaguchi, Tadashi, Shimizu, Yasutomo, Ohta, Makoto, IEEE

    2017 Ieee International Conference on Cyborg and Bionic Systems (Cbs) 150-153 2017年

    DOI: 10.1109/CBS.2017.8266087  

  95. Deformation of stenotic blood vessel model made from Poly (Vinyl Alcohol) Hydrogel by hydrostatic pressure 査読有り

    Shimizu, Yasutomo, Liu, Lei, Kosukegawa, Hiroyuki, Funamoto, Kenichi, Hayase, Toshiyuki, Nakayama, Toshio, Ohta, Makoto, ASME

    Proceedings of the Asme International Mechanical Engineering Congress and Exposition, 2016, Vol. 3 2017年

  96. COMPUTATIONAL FLUID DYNAMICS ANALYSIS OF THE BONE MARROW IN CANCELLOUS BONE AS A NON-NEWTONIAN FLUID 査読有り

    Ohta, Makoto, Sakuma, Wataru, Nakayama, Toshio, Anzai, Hitomi, Ito, Makoto, Sado, Katsuyuki, Nakamura, Shuji, ASME

    Proceedings of the Asme International Mechanical Engineering Congress and Exposition, 2016, Vol. 3 2017年

  97. Manufacture of patient-specific vascular replicas for endovascular simulation using fast, low-cost method. 国際誌 査読有り

    Naoki Kaneko, Toshihiro Mashiko, Taihei Ohnishi, Makoto Ohta, Katsunari Namba, Eiju Watanabe, Kensuke Kawai

    Scientific reports 6 39168-39168 2016年12月15日

    DOI: 10.1038/srep39168  

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    Patient-specific vascular replicas are essential to the simulation of endovascular treatment or for vascular research. The inside of silicone replica is required to be smooth for manipulating interventional devices without resistance. In this report, we demonstrate the fabrication of patient-specific silicone vessels with a low-cost desktop 3D printer. We show that the surface of an acrylonitrile butadiene styrene (ABS) model printed by the 3D printer can be smoothed by a single dipping in ABS solvent in a time-dependent manner, where a short dip has less effect on the shape of the model. The vascular mold is coated with transparent silicone and then the ABS mold is dissolved after the silicone is cured. Interventional devices can pass through the inside of the smoothed silicone vessel with lower pushing force compared to the vessel without smoothing. The material cost and time required to fabricate the silicone vessel is about USD $2 and 24 h, which is much lower than the current fabrication methods. This fast and low-cost method offers the possibility of testing strategies before attempting particularly difficult cases, while improving the training of endovascular therapy, enabling the trialing of new devices, and broadening the scope of vascular research.

  98. Surgical resection of recurrent extrahepatic hepatocellular carcinoma with tumor thrombus extending into the right atrium under cardiopulmonary bypass: a case report and review of the literature. 国際誌 査読有り

    Ohta M, Nakanishi C, Kawagishi N, Hara Y, Maida K, Kashiwadate T, Miyazawa K, Yoshida S, Miyagi S, Hayatsu Y, Kawamoto S, Matsuda Y, Okada Y, Saiki Y, Ohuchi N

    Surgical case reports 2 (1) 110-110 2016年12月

    DOI: 10.1186/s40792-016-0241-7  

    ISSN:2198-7793

  99. Daughter Sac Formation Related to Blood Inflow Jet in an Intracranial Aneurysm. 国際誌 査読有り

    Sin-Ichiro Sugiyama, Hidenori Endo, Shunsuke Omodaka, Toshiki Endo, Kuniyasu Niizuma, Sherif Rashad, Toshio Nakayama, Kenichi Funamoto, Makoto Ohta, Teiji Tominaga

    World neurosurgery 96 396-402 2016年12月

    DOI: 10.1016/j.wneu.2016.09.040  

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    OBJECTIVE: We performed a hemodynamic study of an intracranial aneurysm with a newly developed daughter sac during observation to investigate the role of hemodynamics on the formation of a daughter sac. METHODS: A 75-year-old man underwent magnetic resonance angiography that revealed a large internal carotid artery aneurysm with inflow jet inside the aneurysm. The aneurysm was stable for 18 months, but a new daughter sac developed at the tip of the aneurysm during the next 6 months. The daughter sac seemed to be related to the inflow jet on magnetic resonance angiography. Aneurysm geometries before and after daughter sac formation were reconstructed using the longitudinal data of magnetic resonance angiography. Computational fluid dynamic simulations were conducted under the patient-specific pulsatile inlet conditions measured by magnetic resonance velocimetry. RESULTS: The hemodynamic simulation revealed that the inflow jet impinged on 2 sites of the aneurysm: the right side of the aneurysmal dome and the tip of the aneurysm. The flow impingement caused elevation of pressure at both sites. However, the daughter sac formed at the latter site surrounded by the basal cistern but did not form at the former site that was in contact with the right temporal lobe. CONCLUSIONS: Blood inflow jet caused local elevation of pressure, and the formation of the daughter sac occurred at the site with high pressure but without the surrounding structure, which may cancel the perpendicular wall tension.

  100. Towards the patient-specific design of flow diverters made from helix-like wires: an optimization study 国際誌 査読有り

    Mingzi Zhang, Hitomi Anzai, Bastien Chopard, Makoto Ohta

    BIOMEDICAL ENGINEERING ONLINE 15 (Suppl 2) 159-159 2016年12月

    出版者・発行元:BIOMED CENTRAL LTD

    DOI: 10.1186/s12938-016-0257-z  

    ISSN:1475-925X

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    Background: Flow diverter (FD) intervention is an emerging endovascular technique for treating intracranial aneurysms. High flow-diversion efficiency is desired to accelerate thrombotic occlusion inside the aneurysm; however, the risk of post-stenting stenosis in the parent artery is posed when flow-diversion efficiency is pursued by simply decreasing device porosity. For improving the prognosis of FD intervention, we develop an optimization method for the design of patient-specific FD devices that maintain high levels of porosity.Methods: An automated structure optimization method for FDs with helix-like wires was developed by applying a combination of lattice Boltzmann fluid simulation and simulated annealing procedure. Employing intra-aneurysmal average velocity as the objective function, the proposed method tailored the wire structure of an FD to a given vascular geometry by rearranging the starting phase of the helix wires.Results: FD optimization was applied to two idealized (S and C) vascular models and one realistic (R) model. Without altering the original device porosity of 80%, the flow-reduction rates of optimized FDs were improved by 5, 2, and 28% for the S, C, and R models, respectively. Furthermore, the aneurysmal flow patterns after optimization exhibited marked alterations. We confirmed that the disruption of bundle of inflow is of great help in blocking aneurysmal inflow. Axial displacement tests suggested that the optimal FD implanted in the R model possesses good robustness to tolerate uncertain axial positioning errors.Conclusions: The optimization method developed in this study can be used to identify the FD wire structure with the optimal flow-diversion efficiency. For a given vascular geometry, custom-designed FD structure can maximally reduce the aneurysmal inflow with its porosity maintained at a high level, thereby lowering the risk of post-stenting stenosis. This method facilitates the study of patient-specific designs for FD devices.

  101. Blood Flow Into Basilar Tip Aneurysms: A Predictor for Recanalization After Coil Embolization. 国際誌 査読有り

    Shin-Ichiro Sugiyama, Kuniyasu Niizuma, Kenichi Sato, Sherif Rashad, Misaki Kohama, Hidenori Endo, Toshiki Endo, Yasushi Matsumoto, Makoto Ohta, Teiji Tominaga

    Stroke 47 (10) 2541-7 2016年10月

    DOI: 10.1161/STROKEAHA.116.013555  

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    BACKGROUND AND PURPOSE: Hemodynamic forces may play a role in the recanalization of coiled aneurysms. The purpose of this study was to investigate the influence of presurgical hemodynamics on the efficacy of coil embolization for basilar tip aneurysms. METHODS: We identified 82 patients who underwent endovascular coil embolization for basilar tip aneurysms with a follow-up of >1 year. Presurgical hemodynamics were investigated using computational fluid dynamics with 3-dimensional data derived from rotational angiography. During postprocessing, we quantified the rate of net flow entering the aneurysm through its neck and calculated the proportion of the aneurysmal inflow rate to the basilar artery flow rate. In addition, we investigated the correlation between the basilar bifurcation configuration and the hemodynamics. RESULTS: Twenty-five of the 82 patients were excluded because of difficult vascular geometry reconstruction. Among the 57 examined patients, angiographic recanalization was observed in 19 patients (33.3%). The proportion of the aneurysmal inflow rate to the basilar artery flow rate and a coil packing density <30% were independent and significant predictors for the recanalization of coiled aneurysms. Additional investigation revealed that a small branch angle formed by the basilar artery and the posterior cerebral artery increased blood flow into the aneurysm. CONCLUSIONS: The proportion of the aneurysmal inflow rate to the basilar artery flow rate, influenced by the basilar bifurcation configuration, was an independent and significant predictor for recanalization after coil embolization in basilar tip aneurysms.

  102. 医工学分野におけるCAVE活用

    安西眸, 渡邉和浩, 張明子, Narendra Kurnia Putra, 竹島由里子, 太田信

    可視化情報 36 (143) 20-24 2016年10月

    ISSN:0916-4731

  103. The Transmembrane Domain of a Bicomponent ABC Transporter Exhibits Channel-Forming Activity. 国際誌 査読有り

    Mohammad M Mohammad, Noriko Tomita, Makoto Ohta, Liviu Movileanu

    ACS chemical biology 11 (9) 2506-18 2016年9月16日

    DOI: 10.1021/acschembio.6b00383  

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    Pseudomonas aeruginosa is an opportunistic pathogen that expresses two unique forms of lipopolysaccharides (LPSs) on its bacterial surface, the A- and B-bands. The A-band polysaccharides (A-band PSs) are thought to be exported into the periplasm via a bicomponent ATP-binding cassette (ABC) transporter located within the inner membrane. This ABC protein complex consists of the transmembrane (TMD) Wzm and nucleotide-binding (NBD) Wzt domain proteins. Here, we were able to probe ∼1.36 nS-average conductance openings of the Wzm-based protein complex when reconstituted into a lipid membrane buffered by a 200 mM KCl solution, demonstrating the large-conductance, channel-forming ability of the TMDs. In agreement with this finding, transmission electron microscopy (TEM) imaging revealed the ring-shaped structure of the transmembrane Wzm protein complex. As hypothesized, using liposomes, we demonstrated that Wzm interacts with Wzt. Further, the Wzt polypeptide indeed hydrolyzed ATP but exhibited a ∼75% reduction in the ATPase activity when its Walker A domain was deleted. The distribution and average unitary conductance of the TMD Wzm protein complex were altered by the presence of the NBD Wzt protein, confirming the regulatory role of the latter polypeptide. To our knowledge, the large-conductance, channel-like activity of the Wzm protein complex, although often hypothesized, has not previously been demonstrated. These results constitute a platform for future structural, biophysical, and functional explorations of this bicomponent ABC transporter.

  104. Suppression of Wall Shear Stress inside Intracranial Aneurysms by Simple Stents 査読有り

    Ryuhei yamaguchi, Hitomi Anzai, Gaku Tanaka, Hao Liu, Makoto Ohta

    Neuroscience Communications 2 2016年9月

  105. Tribological aspects of drilling bone biomodel 査読有り

    Y. Muramoto, V. Fridrici, Ph. Kapsa, G. Bouvard, M. Ohta

    Procédés et Génie civil(Journées Internationals Francophones de Tribologie ) JIFT2015 81-89 2016年9月

  106. Effect of elasticity on wall shear stress inside cerebral aneurysm at anterior cerebral artery. 国際誌 査読有り

    Lijian Xu, Michiko Sugawara, Gaku Tanaka, Makoto Ohta, Hao Liu, Ryuhei Yamaguchi

    Technology and health care : official journal of the European Society for Engineering and Medicine 24 (3) 349-57 2016年5月18日

    DOI: 10.3233/THC-161135  

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    BACKGROUND: Many numerical studies have been published with respect to about flow structures around cerebral aneurysm assuming to be rigid. Furthermore, there is little experimental research concerning aneurysm with elastic wall. Wall shear stress in elastic wall comparing with rigid wall should be clarified in experimental approach and verified in CFD. OBJECTIVE: We have experimentally realized elastic aneurysm model accompanying with wall deformation. Wall shear stress was examined for both rigid and elastic aneurysm models in pulsatile flow. METHODS: Effect of elasticity on wall shear stress inside aneurysm induced at the apex of anterior cerebral artery was experimentally examined by particle image velocimetry in vitro. In order to adjust the wall deformation, the pressure adjustment chamber was specially equipped outside the aneurysm wall. RESULTS: Effect of elasticity on wall shear stress was noticed on the comparison with that of rigidity. Wall elasticity reduced the peak magnitude, the spatial and temporal averaged wall shear stress comparing with those of wall rigidity experimentally. These reductions were endorsed by fluid-structure interaction simulation. CONCLUSION: Elastic wall comparing with rigid wall would reduce the peak magnitude, the spatial and temporal averaged wall shear stress acting on vascular wall.

  107. Radiofrequency ablation with a vibrating catheter: A new method for electrode cooling. 国際誌 査読有り

    Kaihong Yu, Tetsui Yamashita, Shigeaki Shingyochi, Kazuo Matsumoto, Makoto Ohta

    Medical engineering & physics 38 (5) 458-67 2016年5月

    DOI: 10.1016/j.medengphy.2016.02.011  

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    A new electrode cooling system using a vibrating catheter is described for conditions of low blood flow when saline irrigation cannot be used. Vibrations of the catheter are hypothesized to disturb blood flow around the electrode, leading to increased convective cooling of the electrode. The aim of this study is to confirm the cooling effect of vibration and investigate the associated mechanisms. As methods, an in vitro system with polyvinyl alcohol-hydrogel (PVA-H) as ablated tissue and saline flow in an open channel was used to measure changes in electrode and tissue temperatures under vibration of 0-63 Hz and flow velocity of 0-0.1 m/s. Flow around the catheter was observed using particle image velocimetry (PIV). Results show that under conditions of no flow, electrode temperatures decreased with increasing vibration frequency, and in the absence of vibrations, electrode temperatures decreased with increasing flow velocity. In the presence of vibrations, electrode temperatures decreased under conditions of low flow velocity, but not under those of high flow velocity. PIV analyses showed disturbed flow around the vibrating catheter, and flow velocity around the catheter increased with higher-frequency vibrations. In conclusion, catheter vibration facilitated electrode cooling by increasing flow around the catheter, and cooling was proportional to vibration frequency.

  108. Difference in Transcranial Doppler Velocity and Patient Age between Proximal and Distal Middle Cerebral Artery Vasospasms after Aneurysmal Subarachnoid Hemorrhage. 国際誌 査読有り

    Misaki Kohama, Shinichiro Sugiyama, Kenichi Sato, Hidenori Endo, Kuniyasu Niizuma, Toshiki Endo, Makoto Ohta, Yasushi Matsumoto, Miki Fujimura, Teiji Tominaga

    Cerebrovascular diseases extra 6 (2) 32-9 2016年

    DOI: 10.1159/000447330  

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    BACKGROUND: Transcranial Doppler (TCD) is used to monitor cerebral vasospasm after subarachnoid hemorrhage (SAH), but its diagnostic ability is reported to be limited. Therefore, the purpose of this study was to investigate the relationship between the diagnosability of TCD and the localization of the vasospasm. METHODS: This retrospective study included 20 patients who presented with symptomatic vasospasm after SAH. All 20 patients underwent daily TCD examinations and cerebral angiography after the onset of delayed cerebral ischemia. We defined positive findings on TCD as a maximum flow velocity >200 cm/s or as a mean flow velocity >120 cm/s at the horizontal part of the middle cerebral artery (MCA). We also examined the site of vasospasm on cerebral angiography. RESULTS: Fourteen patients had true-positive findings on TCD examination, and cerebral angiography showed diffuse vasospasm involving the horizontal segment of the MCA. However, 6 patients had false-negative findings on TCD examination, and cerebral angiography showed vasospasm localized at the distal part of the MCA (the insular and/or cortical segments). The patients with proximal vasospasm were significantly younger than those with distal vasospasm. Blood flow velocity at initial TCD and the increase in velocity at the onset of vasospasm were lower and smaller, respectively, in the distal vasospasm group. CONCLUSIONS: In patients with cerebral vasospasm localized at the distal part of the MCA, flow velocity at the horizontal segment of the MCA did not increase to the level we defined as positive. To avoid such false negatives, a slight increase in velocity on TCD should be considered as positive in distal vasospasm cases, especially in older patients.

  109. Computational Hemodynamic Analysis for the Diagnosis of Atherosclerotic Changes in Intracranial Aneurysms: A Proof-of-Concept Study Using 3 Cases Harboring Atherosclerotic and Nonatherosclerotic Aneurysms Simultaneously. 国際誌 査読有り

    Shin-Ichiro Sugiyama, Hidenori Endo, Kuniyasu Niizuma, Toshiki Endo, Kenichi Funamoto, Makoto Ohta, Teiji Tominaga

    Computational and mathematical methods in medicine 2016 2386031-2386031 2016年

    DOI: 10.1155/2016/2386031  

    eISSN:1748-6718

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    This was a proof-of-concept computational fluid dynamics (CFD) study designed to identify atherosclerotic changes in intracranial aneurysms. We selected 3 patients with multiple unruptured aneurysms including at least one with atherosclerotic changes and investigated whether an image-based CFD study could provide useful information for discriminating the atherosclerotic aneurysms. Patient-specific geometries were constructed from three-dimensional data obtained using rotational angiography. Transient simulations were conducted under patient-specific inlet flow rates measured by phase-contrast magnetic resonance velocimetry. In the postanalyses, we calculated time-averaged wall shear stress (WSS), oscillatory shear index, and relative residence time (RRT). The volume of blood flow entering aneurysms through the neck and the mean velocity of blood flow inside aneurysms were examined. We applied the age-of-fluid method to quantitatively assess the residence of blood inside aneurysms. Atherosclerotic changes coincided with regions exposed to disturbed blood flow, as indicated by low WSS and long RRT. Blood entered aneurysms in phase with inlet flow rates. The mean velocities of blood inside atherosclerotic aneurysms were lower than those inside nonatherosclerotic aneurysms. Blood in atherosclerotic aneurysms was older than that in nonatherosclerotic aneurysms, especially near the wall. This proof-of-concept study demonstrated that CFD analysis provided detailed information on the exchange and residence of blood that is useful for the diagnosis of atherosclerotic changes in intracranial aneurysms.

  110. Manufacture-Oriented Design Optimization for a Flow Diverter Stent Using Lattice Boltzmann Method and Simulated Annealing 国際共著 査読有り

    Mingzi Zhang, Hitomi Anzai, Bastien Chopard, Makoto Ohta

    Advances in Structural and Multidisciplinary Optimization - Proceedings of the 11th World Congress of Structural and Multidisciplinary Optimization (WCSMO-11) 11 310-315 2015年6月

  111. Comparison of intra-aneurysmal velocity magnitude in a patient-specific model among PIV, CFD and MRI

    Yujie Li, Yoneyama Yuuya, Haruo Isada, Takahumi Kosugi, Takashi Kosugi, Makoto Ohta

    2015 ELyT lab Workshop 2015年2月20日

  112. Flow in cancellous bone

    Wataru Sakuma, Hitomi Anzai, Toshio Nakayama, Makoto Ohta

    2015 ELyT lab Workshop 2015年2月20日

  113. Optimization of endovascular prosthesis for the treatment ofcerebral aneurysms

    Hitomi Anzai, Makoto Ohta, Guy courbebaisse, Mingzi Zhang, Bastien Chopard, Yue zhang

    2015 ELyT lab Workshop 2015年2月20日

  114. The Effect of Vibration Ablation Catheter on the Temperature of the Electrode under 30 gf

    Kaihong Yu, Vincent Fridrici, Philippe Kapsa, Makoto Ohta

    2015 ELyT lab Workshop 2015年2月20日

  115. Introduction of Three Strut Optimization Strategies towards the Design of Efficient Flow-Diverter Stents

    Mingzi Zhang, Hitomi Anzai, Makoto Ohta

    2015 ELyT lab Workshop 2015年2月

  116. Preface for the "Special issue on biomedical flow dynamics" 査読有り

    Toshiyuki Hayase, Takehiko Sato, Makoto Ohta

    Journal of Biomechanical Science and Engineering 10 (1) 1-1 2015年

    出版者・発行元:Japan Society of Mechanical Engineers

    DOI: 10.1299/jbse.15preface01  

    ISSN:1880-9863

  117. Parametric study of porous media as substitutes for flow-diverter stent 査読有り

    Ohta, Makoto, Anzai, Hitomi, Miura, Yukihisa, Nakayama, Toshio

    Biomaterials and Biomechanics in Bioengineering 2 (2) 2015年

    DOI: 10.12989/bme.2015.2.2.111  

  118. Accuracy and Reproducibility of Patient-Specific Hemodynamic Models of Stented Intracranial Aneurysms: Report on the Virtual Intracranial Stenting Challenge 2011 査読有り

    Cito, S., Geers, A. J., Arroyo, M. P., Palero, V. R., Pallares, J., Vernet, A., Blasco, J., San Roman, L., Fu, W., Qiao, A., Janiga, G., Miura, Y., Ohta, M., Mendina, M., Usera, G., Frangi, A. F.

    Annals of Biomedical Engineering 43 (1) 154-167 2015年

    DOI: 10.1007/s10439-014-1082-9  

  119. Friction of 316L stainless steel on soft-tissue-like poly(vinyl alcohol) hydrogel in physiological liquid 査読有り

    Kosukegawa, Hiroyuki, Fridrici, Vincent, Laurenceau, Emmanuelle, Kapsa, Philippe, Ohta, Makoto

    Tribology International 82 (PB) 407-414 2015年

    DOI: 10.1016/j.triboint.2014.05.029  

  120. Changes in blood flow due to stented parent artery expansion in an intracranial aneurysm 査読有り

    Futoshi Moria, Makoto Ohta, Teruo Matsuzawa

    TECHNOLOGY AND HEALTH CARE 23 (1) 9-21 2015年

    出版者・発行元:IOS PRESS

    DOI: 10.3233/THC-140871  

    ISSN:0928-7329

    eISSN:1878-7401

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    BACKGROUND: Stent placement is thought to obstruct the inflow of blood to an aneurysm. However, we introduced parent artery expansion and demonstrated that this may reduce the blood flow by the stent. In our previous study using idealized shapes, the results showed that flow reduction was greater than 22.2%, even if the expansion rate was only 6%. Furthermore, the parent artery expansion is predominantly caused by the effect of flow reduction as compared to that of flow reduction due to the obstruction of flow under stent placement. However, a realistic shape is complex and the blood flow also becomes complex flow. It is not understood whether the results of flow in the idealized shape are reflective of flow from a realistic 3D model. Therefore, we examined the effect of parent artery expansion using a realistic model. OBJECTIVE: The aim is to clarify the effects of parent artery expansion on inflow rate, wall shear stress, and oscillatory shear index. METHODS: We used a patient-specific geometry of a human internal carotid artery with an aneurysm. The geometry of parent artery expansion due to oversized stent constructed based on the voronoi diagram. We performed calculations in the unsteady-state situations using constructed models. RESULTS: The complexity of the flow in the aneurysm decreases in case of expanded parent artery. The inflow rate decreases by 33.6% immediately after parent artery expansion alone without a stent. The effect of the parent artery expansion on flow reduction is larger than that of the obstruction flow by stent placement. In addition, wall shear stress and oscillatory shear index on the aneurysm wall decrease by change in blood flow due to the parent artery expansion. CONCLUSION: The effects of the parent artery expansion in a realistic aneurysm model with different stent lengths were evaluated on the basis of a numerical simulation. Although the flow was complex, the parent artery expansion with stent reduces the inflow to the aneurysm and wall shear stress and oscillatory shear index on the aneurysm. Therefore, we suggest that changes in the blood flow because of the parent artery expansion may be identified and, sometimes, is more effective than the obstruction flow due to the stent placement.

  121. Comparative analysis for evaluating the traceability of interventional devices using blood vessel phantom models made of PVA-H or silicone. 国際誌 査読有り

    Chang-Ho Yu, Tae-Kyu Kwon, Chan Hee Park, Makoto Ohta, Sung Hoon Kim

    Technology and health care : official journal of the European Society for Engineering and Medicine 23 Suppl 2 (s2) S301-10-310 2015年

    DOI: 10.3233/THC-150966  

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    OBJECTIVE: In this paper, we investigated the parameters with effective traceability to assess the mechanical properties of interventional devices. METHODS: In our evaluation system, a box-shaped poly (vinyl alcohol) hydrogel (PVA-H) and silicone were prepared with realistic geometry, and the measurement and evaluation of traceability were carried out on devices using load hand force. The phantom models had a total of five curve pathways to reach the aneurysm sac. RESULTS: Traceability depends on the performance of the interventional devices in order to pass through the curved part of the model simulation track. The traceability of the guide wire was found to be much better than that of the balloon and stent loading catheter, as it reached the aneurysm sac in both phantom models. CONCLUSIONS: Observation using the video record is another advantage of our system, because the high transparency of the materials with silicone and PVA-H can allow visualization of the inside of an artery.

  122. Influence of plaque stiffness on deformation and blood flow patterns in models of stenosis. 国際誌 査読有り

    Yasutomo Shimizu, Makoto Ohta

    Biorheology 52 (3) 171-82 2015年

    DOI: 10.3233/BIR-14016  

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    BACKGROUND: Blood flow in stenotic vessels strongly influences the progression of vascular diseases. Plaques in stenotic blood vessels vary in stiffness, which influences plaque behavior and deformation by pressure and flow. Concurrent changes in plaque geometry can, in turn, affect blood flow conditions. Thus, simultaneous studies of blood flow and plaque deformation are needed to fully understand these interactions. OBJECTIVES: This study aims to identify the change of flow conditions attendant to plaque deformation in a model stenotic vessel. METHODS: Three plaques of differing stiffness were constructed on a vessel wall using poly (vinyl alcohol) hydrogels (PVA-H) with defined stiffness to facilitate simultaneous observations of blood flow and plaque deformation. Flow patterns were observed using particle image velocimetry (PIV). RESULTS: Decreases in Reynolds number (Re) with increased plaque deformation suggest that velocity decrease is more critical to establishment of the flow pattern than expansion of the model lumen. Upon exiting the stenosis, the location of the flow reattachment point, shifted further downstream in all models as plaque stiffness decreased and depended on the increase in upstream pressure. CONCLUSIONS: These results suggest that in addition to luminal area, plaque stiffness should be considered as a measure of the severity of the pathology.

  123. Porosity dependency of an optimized stent design for an intracranial aneurysm 査読有り

    Anzai, H., Yoshida, Y., Sugiyama, S., Endo, H., Matsumoto, Y., Ohta, M.

    Technology and Health Care 23 (5) 547-556 2015年

    DOI: 10.3233/THC-151007  

  124. Changes in blood flow due to stented parent artery expansion in an intracranial aneurysm. 国際誌 査読有り

    Futoshi Mori, Makoto Ohta, Teruo Matsuzawa

    Technology and health care : official journal of the European Society for Engineering and Medicine 23 (1) 9-21 2015年

    DOI: 10.3233/THC-140871  

    詳細を見る 詳細を閉じる

    BACKGROUND: Stent placement is thought to obstruct the inflow of blood to an aneurysm. However, we introduced parent artery expansion and demonstrated that this may reduce the blood flow by the stent. In our previous study using idealized shapes, the results showed that flow reduction was greater than 22.2%, even if the expansion rate was only 6%. Furthermore, the parent artery expansion is predominantly caused by the effect of flow reduction as compared to that of flow reduction due to the obstruction of flow under stent placement. However, a realistic shape is complex and the blood flow also becomes complex flow. It is not understood whether the results of flow in the idealized shape are reflective of flow from a realistic 3D model. Therefore, we examined the effect of parent artery expansion using a realistic model. OBJECTIVE: The aim is to clarify the effects of parent artery expansion on inflow rate, wall shear stress, and oscillatory shear index. METHODS: We used a patient-specific geometry of a human internal carotid artery with an aneurysm. The geometry of parent artery expansion due to oversized stent constructed based on the voronoi diagram. We performed calculations in the unsteady-state situations using constructed models. RESULTS: The complexity of the flow in the aneurysm decreases in case of expanded parent artery. The inflow rate decreases by 33.6% immediately after parent artery expansion alone without a stent. The effect of the parent artery expansion on flow reduction is larger than that of the obstruction flow by stent placement. In addition, wall shear stress and oscillatory shear index on the aneurysm wall decrease by change in blood flow due to the parent artery expansion. CONCLUSION: The effects of the parent artery expansion in a realistic aneurysm model with different stent lengths were evaluated on the basis of a numerical simulation. Although the flow was complex, the parent artery expansion with stent reduces the inflow to the aneurysm and wall shear stress and oscillatory shear index on the aneurysm. Therefore, we suggest that changes in the blood flow because of the parent artery expansion may be identified and, sometimes, is more effective than the obstruction flow due to the stent placement.

  125. Numerical analysis and experimental observation of guidewire motion in a blood vessel model. 国際誌 査読有り

    Kazuto Takashima, Shotaro Tsuzuki, Atomu Ooike, Kiyoshi Yoshinaka, Kaihong Yu, Makoto Ohta, Koji Mori

    Medical engineering & physics 36 (12) 1672-83 2014年12月

    DOI: 10.1016/j.medengphy.2014.09.012  

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    We have developed a computer-based system to simulate a guidewire in blood vessels for surgical planning, intra-operative assistance, and to facilitate the design of new guidewires. In this study, we compared simulation results with experimental results for validation of the simulation system. First, we inserted a commercial guidewire into a poly (vinyl alcohol) hydrogel blood vessel model using a two-axis automatic stage and measured the position of the guidewire tip and the contact force between the guidewire and the vessel. The experimental apparatus can be used not only for the validation of numerical analyses, but also as a simulation system. Second, similarly to the experiment, the motion of the guidewire in the blood vessel model was calculated when the proximal part of the guidewire model was pushed and twisted. The model of the guidewire is constructed with viscoelastic springs and segments, and the proximal part of the guidewire model is constrained by the fixed catheter model. Collisions between the guidewire and the vessel are calculated, and the contact forces are determined according to the stiffness of the vessel wall. The same tendency was seen in the trajectories and the contact force of both the experimental and simulated guidewire tips.

  126. Automation of design optimization for intracranial stent

    Hitomi Anzai, Yuuki Yoshida, Mingzi Zhang, Makoto Ohta

    1st International symposium for collaborative research between Tohoku University and Technische Universität Braunschweig 2014年11月11日

  127. Introduction of invitro and insilico analyses for medical equipment

    Makoto Ohta

    1st International symposium for collaborative research between Tohoku University and Technische Universität Braunschweig 2014年11月11日

  128. Numerical Simulation and Experimental Study of Flow Pattern in Cerebral Artery with Aneurysm

    Yujie Li

    Presentation at Linné FLOW Centre & Wallenberg Wood Science Center 2014年10月2日

  129. The Effect of Contact Force on Electrode Temperature and Internal Tissue Temperature during Ablation with a Vibrating Catheter

    Kaihong Yu, Tetsui Yamashita, Shigeaki Shingyochi, Makoto Ohta

    11th International Conference on Flow Dynamics (ICFD2014) 2014年10月

  130. An Optimization Method of FD Stent for Cerebral Aneurysm facing tne Stent Design and Manufacturing Needs

    Mingzi Zhang, Hitomi Anzai, Bastien Chopard, Makoto Ohta

    The Fourth Japan-Switzerland Workshop on Biomechamics (JSB2014) 14 (204) 64 2014年9月3日

  131. Development of Image Guided Minimal Invasive Treatments

    Makoto Ohta, Sho Matsumoto, Xiaobo Han, Mingzi Zhang, Yujie Li, Kaihong Yu, Hitomi Anzai

    The Fourth Japan-Switzerland Workshop on Biomechamics (JSB2014) 14 (204) 100-100 2014年9月3日

  132. Optimization of stent design for intracranial aneurysm

    Hitomi Anzai, Yuuki Yoshida, Makoto Ohta

    The Fourth Japan-Switzerland Workshop on Biomechamics (JSB2014) 14 (204) 62-62 2014年9月3日

  133. Effect of parent artery expansion by stent placement in cerebral aneurysms. 国際誌 査読有り

    Futoshi Mori, Sho Hanida, Makoto Ohta, Teruo Matsuzawa

    Technology and health care : official journal of the European Society for Engineering and Medicine 22 (2) 9-21 2014年8月5日

    DOI: 10.3233/THC-140829  

    eISSN:1878-7401

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    BACKGROUND: Stent placement for cerebral aneurysms leads to a decrease in blood flow. This occurs not only through the direct obstruction of flow but also by the expansion of the parent artery. The latter has been observed in several clinical studies. OBJECTIVE: The goal of this study was to clarify the effects of parent artery expansion after stent treatment on the following: 1) decrease in blood flow to an aneurysm, 2) wall shear stress (WSS), and 3) oscillatory shear index (OSI). METHODS: The parent artery geometry constructed U-shape. The aneurysm location with respect to the U-shaped parent artery was determined according to previous clinical data. We performed calculations in unsteady-state situations using constructed models. RESULTS: Parent artery expansion with stent reduces blood inflow to an aneurysm and WSS of the aneurysm wall, in addition to increasing OSI. The aneurysm position affects the decrease of the inflow rate and WSS ratio and increases the OSI ratio. Expansion causes the majority of effects on flow reduction inside an aneurysm model. Thus, the expansion effects of all samples should not be neglected. CONCLUSION: These data suggest that parent artery expansion and its effect should be measured and included in the total decrease in blood flow. Parent artery expansion may induce intimal hyperplasia, thus increasing the thickness of the aneurysm wall.

  134. Manufacture-oriented Struts Structure Optimization of Flow Diverter for Intracranial Aneurysm 査読有り

    Mingzi Zhang, Hitomi Anzai, Makoto Ohta

    7th World Congress of Biomechanics (WCB2014) 2014年7月10日

  135. The concept of Bundle of Inflow (BOI) for reducing flow in aneurysm

    Makoto Ohta, Hitomi Anzai, Mingzi Zhang, Yujie Li, Xiaobo Han, Kaihong Yu, Toshio Nakayama

    7th World Congress of Biomechanics (WCB2014) 2014年7月10日

  136. Analysys of optimized design of stent

    H. Anzai

    Interdisciplinary Cerebrovascular Symposium 2014年6月3日

  137. Optimization of strut placement in flow diverter stents for four different aneurysm configurations. 国際誌 査読有り

    Hitomi Anzai, Jean-Luc Falcone, Bastien Chopard, Toshiyuki Hayase, Makoto Ohta

    Journal of biomechanical engineering 136 (6) 061006-061006 2014年6月

    DOI: 10.1115/1.4027411  

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    A modern technique for the treatment of cerebral aneurysms involves insertion of a flow diverter stent. Flow stagnation, produced by the fine mesh structure of the diverter, is thought to promote blood clotting in an aneurysm. However, apart from its effect on flow reduction, the insertion of the metal device poses the risk of occlusion of a parent artery. One strategy for avoiding the risk of arterial occlusion is the use of a device with a higher porosity. To aid the development of optimal stents in the view point of flow reduction maintaining a high porosity, we used lattice Boltzmann flow simulations and simulated annealing optimization to investigate the optimal placement of stent struts. We constructed four idealized aneurysm geometries that resulted in four different inflow characteristics and employed a stent model with 36 unconnected struts corresponding to the porosity of 80%. Assuming intracranial flow, steady flow simulation with Reynolds number of 200 was applied for each aneurysm. Optimization of strut position was performed to minimize the average velocity in an aneurysm while maintaining the porosity. As the results of optimization, we obtained nonuniformed structure as optimized stent for each aneurysm geometry. And all optimized stents were characterized by denser struts in the inflow area. The variety of inflow patterns that resulted from differing aneurysm geometries led to unique strut placements for each aneurysm type.

  138. ステントの最適デザインを考える 招待有り

    太田 信, 安西 眸, 吉田 裕貴, Mingzi Zhang, Yujie Li, 中山 敏男

    脳神経外科速報 24 (5) 532-537 2014年5月

  139. Combinational optimization of strut placement for intracranial stent using a realistic aneurysm 査読有り

    Hitomi Anzai, Bastien Chopard, Makoto Ohta

    Journal of Flow Control,Measurement & Visualization 2 (2) 66-76 2014年4月

  140. Effect of Plasma Proteins in Friction of Medical Materials on PVA Hydrogel

    Hiroyuki Kosukegawa, Vincent Fridrici, Emmanuelle Laurenceau, Yu Kaihong, Makoto Ohta, Philippe Kapsa

    Abstract Book 2014年2月

  141. Discussions of pressure distribution in artery with stenosis and aneurysm

    Yujie Li, Hitomi Anzai, Toshio Nakayama, Makoto Ohta

    Abstract 2014年2月

  142. Model Study of Single Ventricular Heart Syndrome and its Treatment

    Mingzi Zhang, Hitomi Anzai, Makoto Ohta

    Abstract 2014年2月

  143. Study of blood flow in cerebral aneurysm with coil

    Makoto Ohta, Toshio Nakayama, Guy Courbebaisse, Hitomi Anzai, Han Xiaobo, Mingzi Zhang, Yujie Li, Kaihong Yu, Carolina Vallecilla, Ricardo A. Corredor

    Abstract 2014年2月

  144. The Effect of Vibration Ablation Catheter on the Temperature of the Electrode under 0.1 m/s Flow

    Kaihong Yu, Makoto Ohta

    Abstract 2014年2月

  145. Effect of parent artery expansion by stent placement in cerebral aneurysms. 国際誌 査読有り

    Futoshi Mori, Sho Hanida, Makoto Ohta, Teruo Matsuzawa

    Technology and health care : official journal of the European Society for Engineering and Medicine 22 (2) 209-23 2014年1月1日

    DOI: 10.3233/THC-140829  

    eISSN:1878-7401

    詳細を見る 詳細を閉じる

    BACKGROUND: Stent placement for cerebral aneurysms leads to a decrease in blood flow. This occurs not only through the direct obstruction of flow but also by the expansion of the parent artery. The latter has been observed in several clinical studies. OBJECTIVE: The goal of this study was to clarify the effects of parent artery expansion after stent treatment on the following: 1) decrease in blood flow to an aneurysm, 2) wall shear stress (WSS), and 3) oscillatory shear index (OSI). METHODS: The parent artery geometry constructed U-shape. The aneurysm location with respect to the U-shaped parent artery was determined according to previous clinical data. We performed calculations in unsteady-state situations using constructed models. RESULTS: Parent artery expansion with stent reduces blood inflow to an aneurysm and WSS of the aneurysm wall, in addition to increasing OSI. The aneurysm position affects the decrease of the inflow rate and WSS ratio and increases the OSI ratio. Expansion causes the majority of effects on flow reduction inside an aneurysm model. Thus, the expansion effects of all samples should not be neglected. CONCLUSION: These data suggest that parent artery expansion and its effect should be measured and included in the total decrease in blood flow. Parent artery expansion may induce intimal hyperplasia, thus increasing the thickness of the aneurysm wall.

  146. Computational simulations in the cardiovascular system. 国際誌 査読有り

    Aike Qiao, Hai-Chao Han, Makoto Ohta, Yi Qian

    TheScientificWorldJournal 2014 421061-421061 2014年

    DOI: 10.1155/2014/421061  

  147. Classification of Blood Flow in Cerebral Aneurysm Considering the Parent Artery 査読有り

    太田 信

    ASME 2013 International Mechanical Engineering Congress and Exposition 3A IMECE2013-63922 2014年

  148. PIV ANALYSIS OF THE FLOW PATTERN AROUND AN ABLATION CATHETER TO OBSERVE THE FLOW EFFECT ON THE ELECTRODE 査読有り

    Yu, Kaihong, Yamashita, Tetsui, Shingyochi, Shigeaki, Matsumoto, Kazuo, Ohta, Makoto, ASME

    Proceedings of the Asme International Mechanical Engineering Congress and Exposition, 2013, Vol 3a IMECE2013-62791 2014年

    DOI: 10.1115/IMECE2013-62791  

  149. Observation of filling process in injection molding for fabrication of bone biomodel

    Masashi Ohtake, Kei Ozawa, Makoto Ohta

    IFMBE Proceedings 43 315-318 2014年

    出版者・発行元:Springer Verlag

    DOI: 10.1007/978-3-319-02913-9_80  

    ISSN:1680-0737

    詳細を見る 詳細を閉じる

    The injection molding is one of the major process methods for fabricating specially for composite materials. This method is useful for fabricating complex shape and advanced properties of materials such as bone model, recycled plastics or building materials. A bone biomodeling requires a realistic mechanical properties and the geometry as use of mechanical tests of medical devices such as bone screw or drill. The development of bone biomodel also requires the composite materials and the method of an injection molding to produce a unified model for the tests. The mechanical properties of bone biomodeling, specially the strength or the fracture toughness have a strong relation not only to the compound condition, but also to the filling process under injection molding, because the geometry of bone has a large volume and the flow in the injection is not stable. Therefore, visualization of flow of materials in the molding is important to grasp the filling process and microstructure of the model. However, the observation of flow during the molding is hard because the molding system is, in general, not to be transparent. Ozawa et al. carried out the observation of flow behavior with tungsten fiber using micro-CT. The orientation and distribution of fibers shows the flow direction. However, the image of micro- CT scanning shows only “a result of the filling process of materials in injection”. To reveal the filling process, we develop a visible system of injection by using Poly (vinyl alcohol) (PVA) solution with good transparency and capability of changing its viscosity. Then, PVA solution can be detected by using a camera for analyzing visualization process such as particle image velocimetry (PIV). We found PVA solution is useful for investigation of relationship between flow behavior and viscosity of the material in the injection molding.

  150. Study of Parameters for Evaluating the Pushability of Interventional Devices Using Box-shaped Blood Vessel Biomodels Made of PVA-H or Silicone 国際誌 査読有り

    太田 信

    BIO-MEDICAL MATERIALS AND ENGINEERING 24 (1) 961-8 2014年

    DOI: 10.3233/BME-130891  

  151. Simulation of hemodynamics in artery with aneurysm and stenosis with different geometric configuration 査読有り

    Yujie Li, Hitomi Anzai, Toshio Nakayama, Yasumoto Shimizu, Yukihisa Miura, Aike Qiao, Makoto Ohta

    Journal of Biomechanical Science and Engineering 9 (1) 2014年

    出版者・発行元:Japan Society of Mechanical Engineers

    DOI: 10.1299/jbse.2014jbse0003  

    ISSN:1880-9863

    詳細を見る 詳細を閉じる

    In previous published research, the deployment of flow-diversion increases the intra-aneurysmal pressure by 20 mmHg in the case with a pre-aneurysm stenosis. The purpose of this study is to learn the influence to the aneurysm when a pre-aneurysm stenosis exists which may threaten people's health even more severely. In the present research, idealized models of straight and curved blood vessels with both aneurysm and pre-aneurysm stenosis were established, with altering the degree of stenosis, the distance between stenosis and aneurysm and the curvature of parent artery. As the degree of stenosis increases, the reattachment length increases in straight vessels. Different positions of reattachment points to aneurysm neck affect the flow pattern inside the aneurysm. In the model with higher degree of stenosis and smaller distance between stenosis and aneurysm, the flow pattern and the direction of vortexes inside the aneurysm are affected by the recirculation after stenosis. Driven by inertial force, reattachment length decreases as the curvature of the parent artery increases, and stream inside the aneurysm is affected only when the distance between stenosis and aneurysm is short enough. In all models, the pressure drop inside the aneurysm increases as the degree of stenosis increases, creating a lower pressure environment in the aneurysm. © 2014 The Japan Society of Mechanical Engineers.

  152. A Study on Multiscale Model in the presence of Systemic-to-Pulmonary Shunt utilizing Open-source CFD software Palabos

    M.Z. Zhang, H. Anzai, Y.J. Liu, M. Ohta

    APCOM & ISCM 2013年12月

  153. Hemodynamic Numerical Simulation in Artery Complicated with both Stenosis and Aneurysm in Different Shape and Position

    Y.J. Li, H. Anzai, T. Nakayama, Y. Shimizu, Y. Miura, A.K. Qiao, M. Ohta

    APCOM & ISCM 2013年12月

  154. Analysis of Relationship between Lipid Environment and Protein Nanopore Properties- Toward Creation of Red Blood Cell Model with Various Membrane Strength-

    Noriko Tomita, Stephan Wilkens, Liviu Movileanu, Makoto Ohta

    Tenth International Conference on Flow Dynamics Proceedings 2013年11月27日

  155. Optimized Stent 招待有り

    Makoto Ohta, Hitomi Anzai, Toshio Nakayama, Xiaobo Han, Noriko Tomita

    The 10th ICFD, Sendai 580-581 2013年11月27日

  156. Membrane Channel Dynamics Depended on Lipid Environment

    Noriko Tomita, Liviu Movileanu, Makoto Ohta

    Tenth International Conference on Flow Dynamics Proceedings 614-615 2013年11月26日

  157. Relative residence time prolongation in intracranial aneurysms: a possible association with atherosclerosis. 国際誌 査読有り

    Shin-ichiro Sugiyama, Kuniyasu Niizuma, Toshio Nakayama, Hiroaki Shimizu, Hidenori Endo, Takashi Inoue, Miki Fujimura, Makoto Ohta, Akira Takahashi, Teiji Tominaga

    Neurosurgery 73 (5) 767-76 2013年11月

    DOI: 10.1227/NEU.0000000000000096  

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    BACKGROUND: Intracranial aneurysms can have atherosclerotic wall properties that may be important in predicting aneurysm history or estimating the potential risks of surgical treatments. OBJECTIVE: To investigate hemodynamic characteristics of atherosclerotic lesions in intracranial aneurysms using computational fluid dynamics. METHODS: Intraoperative video recordings of 30 consecutive patients with an unruptured middle cerebral artery aneurysm were examined to identify atherosclerotic lesions on an aneurysm wall. For computational fluid dynamics analyses, geometries of aneurysms and adjacent arteries were reconstructed from 3-dimensional rotational angiography. Transient simulations were conducted under patient-specific pulsatile inlet conditions measured by phase-contrast magnetic resonance velocimetry. Three hemodynamic wall parameters were calculated: time-averaged wall shear stress, oscillatory shear index, and relative residence time (RRT). Statistical analyses were performed to discriminate the risk factors of atherosclerotic lesion formation. RESULTS: Among 30 aneurysms, 7 atherosclerotic lesions with remarkable yellow lipid deposition were identified in 5 aneurysms. All 7 atherosclerotic lesions spatially agreed with the area with prolonged RRT. Univariate analysis revealed that male sex (P = .03), cigarette smoking (P = .047), and maximum RRT (P = .02) are significantly related to atherosclerotic lesion on the intracranial aneurysmal wall. Of those variables that influenced atherosclerotic lesion of the intracranial aneurysmal wall, male sex (P = .005) and maximum RRT (P = .004) remained significant in the multivariate regression model. CONCLUSION: The area with prolonged RRT colocalized with atherosclerotic change on the aneurysm wall. Male sex and maximum RRT were independent risk factors for atherogenesis in intracranial aneurysms.

  158. Channel Properties of Membrane Proteins on Lipid Bilayers

    Makoto Ohta, Liviu Movileanu, Noriko Tomita

    AFI/TFI 2013年11月

  159. Classification of flow pattern in neck based considering the parent artery curves and stent implantation

    Toshio Nakayama, Makoto Ohta

    CLASSIFICATION OF FLOW PATTERN IN NECK BASED CONSIDERING THE PARENT ARTERY CURVES AND STENT IMPLANTATION 2013年11月

  160. Development of a Program for Blood flow and Cell Behaviors Based on LBM Method

    Makoto Ohta, Bastien Chopard, Hitomi Anzai

    AFI/TFI 2013年11月

  161. Development of Visualization System for Injection Molding by using PVA

    Masashi Ohtake, Kei Ozawa, Ken Nakajima, Makoto Ohta

    Tenth International Conference on Flow Dynamics Proceedings 638-639 2013年11月

  162. Influence of Ni-Ti Wire under the Shear Stress Environment on Endothelialization

    Sho Matsumoto, Han Xiaobo, Hisatoshi Kobayashi, Noriko Tomita, Makoto Ohta

    Tenth International Conference on Flow Dynamics Proceedings 602-603 2013年11月

  163. Optimization of stent design to increase the porosity

    Yuuki Yoshida, Hitomi Anzai, Makoto Ohta

    Optimization of stent design to increase the porosity 2013年11月

  164. Research of Friction and Drilling on Bio-composite Model

    Makoto Ohta, Kei Ozawa, Vincent Fridrici, Philippe Kapsa

    AFI/TFI 2013年11月

  165. Stagnant Blood Flow in Intracranial Aneurysms: A Possible Association with Atherosclerosis

    Shin-ichiro Sugiyama, Toshio Nakayama, Kenichi Funamoto, Daichi Suzuki, Kuniyasu Niizuma, Makoto Ohta, Teiji Tominaga

    Tenth International Conference on Flow Dynamics Proceedings 592-593 2013年11月

  166. The Effect of Vibration of Ablation Catheter on the Temperature of the Electrode

    Kaihong Yu, Tetsui Yamanaka, Shigeaki Shigyochi, Makoto Ohta

    Tenth International Conference on Flow Dynamics Proceedings 644-645 2013年11月

  167. High fidelity virtual stenting (HiFiVS) for intracranial aneurysm flow diversion: in vitro and in silico. 国際誌 査読有り

    Ding Ma, Travis M Dumont, Hiroyuki Kosukegawa, Makoto Ohta, Xinjian Yang, Adnan H Siddiqui, Hui Meng

    Annals of biomedical engineering 41 (10) 2143-56 2013年10月

    DOI: 10.1007/s10439-013-0808-4  

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    A flow diverter (FD) is a flexible, densely braided stent-mesh device placed endoluminally across an intracranial aneurysm to induce its thrombotic occlusion. FD treatment planning using computational virtual stenting and flow simulation requires accurate representation of the expanded FD geometry. We have recently developed a high fidelity virtual stenting (HiFiVS) technique based on finite element analysis to simulate detailed FD deployment processes in patient-specific aneurysms (Ma et al. J. Biomech. 45:2256-2263,(2012)). This study tests if HiFiVS simulation can recapitulate real-life FD implantation. We deployed two identical FDs (Pipeline Embolization Device) into phantoms of a wide-necked segmental aneurysm using a clinical push-pull technique with different delivery wire advancements. We then simulated these deployment processes using HiFiVS and compared results against experimental recording. Stepwise comparison shows that the simulations precisely reproduced the FD deployment processes recorded in vitro. The local metal coverage rate and pore density quantifications demonstrated that simulations reproduced detailed FD mesh geometry. These results provide validation of the HiFiVS technique, highlighting its unique capability of accurately representing stent intervention in silico.

  168. Guidewire Simulator for Intravacular Surgery

    K. Takashima, S. Tsuzuki, M. Umetani, K. Yoshinaka, Y. Hoshino, M. Ohta, K. Mori

    UKSAES2013 2013年10月

  169. Optimization of blood flow for intracranial stent

    Makoto Ohta, Hitomi Anzai, Han Xiaobo

    Workshop on Flow Dynamics related to Energy, Aerospace and Material Processing 2013年9月10日

  170. Density change of smooth muscle cells in co-culture model under shear stress with spatial gradient related to the development of cerebral aneurysm

    Sho Matsumoto, Han Xiaobo, Makoto Ohta, Noriko Tomita

    the5th EMBO meeting advancing the life science 2013 AMSTERDAM abstracts 2013年9月

  171. Electrophysiological properties of engineered FhuA ΔC/Δ4L protein nanopore affected by lipid bilayer environment

    Noriko Tomita, Liviu Movileanu, Makoto Ohta

    the5th EMBO meeting advancing the life science 2013 AMSTERDAM abstracts 2013年9月

  172. Friction of Medical Materials on PVA Hydrogel in Physiological Lubrication

    Hiroyuki Kosukegawa, Vincent Fridrici, Emmanuelle Laurenceau, Makoto Ohta, Philippe Kapsa

    World Tribology Congress 2013 2013年9月

  173. In vitro study of ultrasound radiation force-driven twinkling sign using PVA-H gel and glass beads tissue-mimicking phantom. 査読有り

    Lei Liu, Kenichi Funamoto, Kei Ozawa, Makoto Ohta, Toshiyuki Hayase, Masafumi Ogasawara

    Journal of medical ultrasonics (2001) 40 (3) 197-203 2013年7月

    DOI: 10.1007/s10396-012-0429-9  

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    The twinkling sign observed in ultrasound coded-excitation imaging (e.g., GE B-Flow) has been reported in previous research as a potential phenomenon to detect micro calcification in soft tissue. However, the mechanism of the twinkling sign has not been clearly understood yet. We conducted an in vitro experiment to clarify the mechanism of the twinkling sign by measuring a soft tissue-mimicking phantom with ultrasonic and optical devices. A soft tissue-mimicking phantom was made of poly(vinyl alcohol) hydro (PVA-H) gel and 200-μm-diameter glass beads. We applied ultrasound to the phantom using medical ultrasound diagnostic equipment to observe the twinkling sign of glass beads. Optical imaging with a laser sheet and a high-speed camera was performed to capture the scatter lights of the glass beads with and without ultrasound radiation. The scatter lights from the glass beads were quantified and analyzed to evaluate their oscillations driven by the ultrasound radiation force. The twinkling sign from the glass beads embedded in the PVA-H gel soft tissue phantom was observed in ultrasound B-Flow color imaging. The intensity and oscillation of the scattered lights from the glass beads showed significant difference between the cases with and without ultrasound radiation. The results showed a close relationship between the occurrence of the twinkling sign and the variations of the scatter lights of glass beads, indicating that ultrasound radiation force-driven micro oscillation causes the twinkling sign of micro calcification in soft tissue.

  174. Comparison of flow patterns around stenotic area in elastic PVA-H model and in rigid-like silicone model

    Yasutomo Shimizu, Masanori Kuze, Ashkan Javadzadegan, Masud Behnia, Makoto Ohta

    10TH INTERNATIONAL SYMPOSIUM ON PARTICLE IMAGE VELO CIMETRY – PIV13 2013年7月

  175. Correlation between Reynolds number and stenosis morphology in eccentric and concentric artery models

    Ashkan Javadzadegan, Yasutomo Shimizu, Masud Behnia, Makoto Ohta

    10TH INTERNATIONAL SYMPOSIUM ON PARTICLE IMAGE VELO CIMETRY – PIV13 2013年7月

  176. In vitro strain measurements in cerebral aneurysm models for cyber-physical diagnosis. 国際誌 査読有り

    Chaoyang Shi, Masahiro Kojima, Hitomi Anzai, Carlos Tercero, Seiichi Ikeda, Makoto Ohta, Toshio Fukuda, Fumihito Arai, Zoran Najdovski, Makoto Negoro, Keiko Irie

    The international journal of medical robotics + computer assisted surgery : MRCAS 9 (2) 213-22 2013年6月

    DOI: 10.1002/rcs.1487  

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    BACKGROUND: The development of new diagnostic technologies for cerebrovascular diseases requires an understanding of the mechanism behind the growth and rupture of cerebral aneurysms. To provide a comprehensive diagnosis and prognosis of this disease, it is desirable to evaluate wall shear stress, pressure, deformation and strain in the aneurysm region, based on information provided by medical imaging technologies. METHODS: In this research, we propose a new cyber-physical system composed of in vitro dynamic strain experimental measurements and computational fluid dynamics (CFD) simulation for the diagnosis of cerebral aneurysms. A CFD simulation and a scaled-up membranous silicone model of a cerebral aneurysm were completed, based on patient-specific data recorded in August 2008. In vitro blood flow simulation was realized with the use of a specialized pump. A vision system was also developed to measure the strain at different regions on the model by way of pulsating blood flow circulating inside the model. RESULTS: Experimental results show that distance and area strain maxima were larger near the aneurysm neck (0.042 and 0.052), followed by the aneurysm dome (0.023 and 0.04) and finally the main blood vessel section (0.01 and 0.014). These results were complemented by a CFD simulation for the addition of wall shear stress, oscillatory shear index and aneurysm formation index. Diagnosis results using imaging obtained in August 2008 are consistent with the monitored aneurysm growth in 2011. CONCLUSION: The presented study demonstrates a new experimental platform for measuring dynamic strain within cerebral aneurysms. This platform is also complemented by a CFD simulation for advanced diagnosis and prediction of the growth tendency of an aneurysm in endovascular surgery.

  177. Application of optimization for design of intracranial stent with blood flow reduction as objective function

    Hitomi Anzai, Jean-Luc Falcone, Bastien Chopard, Makoto Ohta

    WCSMO-10 10th World Congress and Structual and Multidisciplinary Optimization Program Book 2013年5月

  178. Microbial Pore-Forming Protein Properties Depended on Lipid Environment

    Noriko Tomita, Liviu Movileanu, Stephan Wilkens, Makoto Ohta

    NIH Tohoku University JSPS Symposium Program and Abstracts 2013年5月

  179. Does the lipid environment impact the open-state conductance of an engineered β-barrel protein nanopore? 国際誌 査読有り

    Tomita N, Mohammad MM, Niedzwiecki DJ, Ohta M, Movileanu L

    Biochim Biophys Acta. Biomembrane, 1828 (3) 1057-65 2013年3月

    DOI: 10.1016/j.bbamem.2012.12.003  

  180. Evaluation for Drilling Properties of Bone Models

    Kei Ozawa, Yuji KATAKURA, Yukihiko SHIBATA, Gaëtan BOUVARD, Vincent FRIDRICI, Philippe KAPSA, Makoto OHTA

    abstract book 2013年3月

  181. Friction of Medical Materials in Contact with PVA Hydrogel in Physiological Conditions

    Hiroyuki Kosukegawa, FRIDRICI Vincent, LAURENCEAU Emmanuelle, OHTA Makoto, KAPSA Philippe

    abstract book 2013年3月

  182. Study of the coil effect within an intracranial aneurysm

    Guy Courbebaisse, Makoto Ohta, Toshio Nakayama

    Abstract book 2013年3月

  183. Preface 査読有り

    Makoto Ohta, Toshiyuki Hayase

    Journal of Biomechanical Science and Engineering 8 (3) 197-197 2013年

    DOI: 10.1299/jbse.8.197  

    ISSN:1880-9863

  184. INFLUENCE OF PLAQUE STIFFNESS ON CHANGE OF BLOOD VESSEL GEOMETRY LEADING HEMODYNAMICAL CHANGES IN PVA-H STENOSIS MODELS 査読有り

    Shimizu, Yasutomo, Shida, Shuya, Funamoto, Kenichi, Hayase, Toshiyuki, Ohta, Makoto, ASME

    International Mechanical Engineering Congress and Exposition - 2012, Vol 2: Biomedical and Biotechnology IMECE2012 87073 2013年

    DOI: 10.1115/IMECE2012-87073  

  185. Bioengineering materials and conditions for obtaining low friction with PVA hydrogels 査読有り

    Boyko Stoimenov, Vincent Fridrici, Philippe Kapsa, Hiroyuki Kosukegawa, Makoto Ohta

    Tribology Online 8 (1) 140-152 2013年

    DOI: 10.2474/trol.8.140  

    ISSN:1881-218X 1881-2198

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    Biological materials that make up the body organs and tissues are soft, wet and visco-elastic. Hydrogels can mimic these aspects and show promise for bio-medical applications. Their tribological properties are very important for promising applications such as artificial cartilage and bio-models for endovascular surgery training. The present study investigates the friction of polyvinyl alcohol (PVA) hydrogel against nine different metallic and non-metallic bio-compatible engineering materials likely to occur as countermaterials in these two applications. All the materials exhibited a characteristic velocity-dependent peak friction coefficient. Comparing the peaks, we find that lowest peak friction coefficient is produced by ceramics and glass (μ &lt 0.05), followed by metal alloys (μ &lt 0.05-0.08) and highest for polymers (0.4 &lt μ &lt 1.5), including PTFE which typically has very low-adhesion. Our results suggest that to achieve low friction, polymers should be avoided as a counter-material to PVA-hydrogels. It is also shown that PVA surface roughness is critical for achieving early transition to elasto-hydrodynamic lubrication and low friction, as shown in our comparative calculations with two different values of surface roughness of the gel. In the mixed lubrication region, the general trend is for friction to increase with roughness of the counterbody, but internal damping properties and adhesion also play important role, as shown by a simple linear model fit. Copyright © 2013 Japanese Society of Tribologists.

  186. Flow observations in elastic stenosis biomodel with comparison to rigid-like model. 国際誌 査読有り

    Yasutomo Shimizu, Ashkan Javadzadegan, Toshiyuki Hayase, Makoto Ohta

    Technology and health care : official journal of the European Society for Engineering and Medicine 21 (4) 305-14 2013年

    DOI: 10.3233/THC-130725  

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    BACKGROUND: Plaques in blood vessels exhibit a wide range of stiffness depending on disease conditions: stiffness is an important factor in plaque behavior. The geometrical change in plaque based on its behavior can affect blood flow patterns. Thus, it is important to study both blood flow and deformation of plaques and blood vessels. OBJECTIVE: This study aims to identify the differences in flow conditions between in vitro models to discuss experimental materials for arterial wall and flow observation. METHODS: In order to observe the blood flow pattern and plaque deformation simultaneously, a PVA-H stenosis model was used. In addition, a silicone model was also used as a rigid-like model for comparison with the PVA-H model. PIV was employed to measure the flow velocity distribution and determine the flow levels in the models. RESULTS: PVA-H model exhibits expansion with an increase in upstream pressure and silicone model maintains the diameter. The expansion depends on their mechanical properties and influences flow conditions such as velocity changes and RAP in the parent artery. The balance between the expansion and change in flow conditions determines the final geometries of PVA-H model and flow pattern. CONCLUSIONS: The results suggest that the stiffness measurement for blood vessels and plaques such as ultrasound measurements would be important for accurate treatments.

  187. Correlation between Reynolds number and eccentricity effect in stenosed artery models. 国際誌 査読有り

    Ashkan Javadzadegan, Yasutomo Shimizu, Masud Behnia, Makoto Ohta

    Technology and health care : official journal of the European Society for Engineering and Medicine 21 (4) 357-67 2013年

    DOI: 10.3233/THC-130736  

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    BACKGROUND: Flow recirculation and shear strain are physiological processes within coronary arteries which are associated with pathogenic biological pathways. Distinct Quite apart from coronary stenosis severity, lesion eccentricity can cause flow recirculation and affect shear strain levels within human coronary arteries. OBJECTIVE: The aim of this study is to analyse the effect of lesion eccentricity on the transient flow behaviour in a model of a coronary artery and also to investigate the correlation between Reynolds number (Re) and the eccentricity effect on flow behaviour. METHODS: A transient particle image velocimetry (PIV) experiment was implemented in two silicone based models with 70% diameter stenosis, one with eccentric stenosis and one with concentric stenosis. RESULTS: At different times throughout the flow cycle, the eccentric model was always associated with a greater recirculation zone length, maximum shear strain rate and maximum axial velocity; however, the highest and lowest impacts of eccentricity were on the recirculation zone length and maximum shear strain rate, respectively. Analysis of the results revealed a negative correlation between the Reynolds number (Re) and the eccentricity effect on maximum axial velocity, maximum shear strain rate and recirculation zone length. CONCLUSIONS: As Re number increases the eccentricity effect on the flow behavior becomes negligible.

  188. Friction Properties of Medical Metallic Alloys on Soft Tissue–Mimicking Poly(Vinyl Alcohol) Hydrogel Biomodel 査読有り

    Hiroyuki Kosukegawa, Vincent Fridrici, Philippe Kapsa, Yuji Sutou, Koshi Adachi, Makoto Ohta

    Tribology Letter 51 (3) 311-321 2013年

    DOI: 10.1007/s11249-013-0165-3  

  189. Modeling Flow Diverter Stent using Porous Media

    Makoto Ohta, Yukihisa Miura, Hitomi Anzai, Toshio Nakayama

    Abstract 2012年10月

  190. Experimental Validation of FEA-Based Workflow to Simulate Flow Diverting Stent Deployment in Intracranial Aneurysms

    Hui Meng, Travis Dumont, Hiroyuki Kosukegawa, Ding Ma, Makoto Ohta

    Abstract 2012年10月

  191. Stent designs for efficient reduction of intra-aneurismal flow with various aneurysms

    Hitomi Anzai, Jean-Luc Falcone, Bastien Chopard, Makoto Ohta

    Abstract 2012年10月

  192. Classification of Flow pattern in neck based on parent artery configuration and optimized stent implantation

    Toshio Nakayama, Shinkyu Jeong, Karkenahalli Srinivas, Makoto Ohta

    Abstract 2012年10月

  193. Hemodynamics Effect of Y-Configuration Stenting on Basilar Tip Aneurysm

    Masahiro Kojima, Toshio Fukuda, Keiko Irie, Makoto Negoro, Makoto Ohta

    Abstract 2012年10月

  194. Ultrasound Radiation Force Driven B-Flow Twinkling Sign for Microcalcification Detection

    L. Liu, K. Funamoto, K. Ozawa, M. Ohta, T. Hayase, M. Ogasawara

    Proceedings of the 12th International Symposium on Advanced Fluid Information and Transdisciplinary Fluid Integration (AFI/TFI-2012) 86-87 2012年9月20日

  195. Electrophysiological Properties of Bacterial Membrane Channel Proteins Depending on Lipid Component and Bilayer Stability

    Noriko Tomita, Liviu Movileanu, Makoto Ohta

    Proceedings of [Ninth International Conference on Flow Dynamics 2012年9月20日

  196. Effect of the Aspect Ratio of Cerebral Aneurysms on Blood Flow Reduction after Optimized Stent Placement

    Toshio Nakayama, Shinkyu Jeong, Karkenahalli Srinivas, Makoto Ohta

    Proceedings of Ninth International Conference on Flow Dynamics 424-425 2012年9月20日

  197. Optimum Design of Flow Diverter Stent Associated with Arterial Geometries

    Hitomi Anzai, Jean-Juc Falcone, Bastien Chopard, Makoto Ohta

    Proceedings Ninth International Conference on Flow Dynamics 2012年9月

  198. Properties of N-butyl cyanoacrylate-iodized oil mixtures for arterial embolization: in vitro and in vivo experiments. 国際誌 査読有り

    Chiaki Takasawa, Kazumasa Seiji, Kenichi Matsunaga, Toshio Matsuhashi, Makoto Ohta, Shuya Shida, Kei Takase, Shoki Takahashi

    Journal of vascular and interventional radiology : JVIR 23 (9) 1215-1221 2012年9月

    DOI: 10.1016/j.jvir.2012.06.022  

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    PURPOSE: To examine the properties of N-butyl cyanoacrylate (NBCA) and iodized oil (lipiodol [Lip]) in vitro and in vivo for safe and effective embolization. MATERIALS AND METHODS: Viscosity, polymerization time, and diffusing capacity were evaluated according to the NBCA/Lip ratio in vitro. Additionally, the effect of the NBCA/Lip ratio on arterial embolization was evaluated in vivo; various ratios of NBCA/Lip were injected into the renal arteries of adult beagles, after which the embolization effect following transcatheter arterial embolization was quantitatively investigated histopathologically and using computed tomography (CT) volumetry. RESULTS: The viscosity of NBCA/Lip increased, polymerization time was prolonged, and diffusing capacity increased as the NBCA density decreased. As the NBCA density decreased, embolic material was recognized in smaller diameter arteries, and embolization of a larger vascular bed was accomplished. The NBCA/Lip mixture with a low density of NBCA was located more peripherally from the catheter tip, and embolization of more peripheral and smaller diameter arteries was achieved. CONCLUSIONS: The relationships of properties of NBCA/Lip in vitro and embolization effects in vivo of various ratios of NBCA/Lip were quantitatively examined and compared. The results of this study are useful for safe and effective embolization.

  199. Comparison between Agarose gel and PVA-H Biomodels for Evaluation of Ablation Catheter

    Kaihong Yu, Tetsuya Yamashita, Makoto Ohta

    Proceedings Ninth International Conference on Flow Dynamics 2012年9月

  200. Size Validation of an Adrenal Vein Model for Development of an In Vitro Model with Realistic Geometrical Structure

    Yusuke Hoshino, Kei Takase, Kazumasa Seiji, Makoto Ohta

    Proceedings Ninth International Conference on Flow Dynamics 620-622 2012年9月

  201. Flow Analysis in Cerebral Aneurysm Model with Transparent Coils Placement

    Masanori Kuze, Makoto Ohta

    Proceedings Ninth International Conference on Flow Dynamics 656-657 2012年9月

  202. Relationship between Fluid Shear Stress and the Phenotype Change of Smooth Muscle Cells in a Co-culture Model

    Xiaobo Han, Naoya Sakamoto, Noriko Tomita, Meng Hui, Masaaki Sato, Makoto Ohta

    Proceedings Ninth International Conference on Flow Dynamics 614-615 2012年9月

  203. Friction and thermal Properties in Drilling of Bone Biomodels

    Kei Ozawa, Yuji Katakura, Yukihiko Shibata, Philippe Kapsa, Vincent Fridrici, Gaetan Bouvard, Makoto Ohta

    Proceedings Ninth International Conference on Flow Dynamics 584-585 2012年9月

  204. Neumerical and Experimental Study of Flow in Stenosis models with Several Mechanical Properties

    Yasutomo Shimizu, Shuya Shida, Ashkan Javadzadegan, Kenichi Funamoto, Toshiyuki Hayase, Makoto Ohta

    Proceedings Ninth International Conference on Flow Dynamics 422-423 2012年9月

  205. Measurement of Pressure Drop for Modeling Intracranial Flow Diverter Stent Using Porous Medium

    Yukihisa Miura, Hitomi Anzai, Toshio Nakayama, Toshiyuki Hayase, Makoto Ohta

    Proceedings Ninth International Conference on Flow Dynamics 586-587 2012年9月

  206. Simulation of Hemodynamics in Artery with Aneurysm and Stenosis

    Yujie Li, Hitomi Anzai, Toshio Nakayama, Yasutomo Shimizu, Yukihisa miura, Aike Qiao, Makoto Ohta

    不明 410-411 2012年9月

  207. A Development of Lattice Boltzmann Model and Lumped Parameter Model Connection for Cardiovascular Multiscale Analysis

    Mingzi Zhang, Hitomi Anzai, Youjun Liu, Makoto Ohta

    不明 412-413 2012年9月

  208. Tribology of Medical Materials on PVA-H Biomodel

    Hiroyuki Kosukegawa, Makoto Ohta, Vincent Fridrici, Philippe Kapsa

    不明 102-103 2012年9月

  209. Characterization of Design of Stent Strut Positioning using LBM Method

    Makoto Ohta, Bastien Chopard, Hitomi Anzai

    不明 98-99 2012年9月

  210. Channel Properties of Membrane Proteins on Lipid Bilayer

    Makoto Ohta, Liviu Movileanu, Noriko Tomita

    不明 100-101 2012年9月

  211. Oscillatory and Stagnant Flow in Intracranial Aneurysms: A Possible Association with Atherosclerosis

    Shin-ichiro Sugiyama, Hiroaki Shimizu, Toshio Nakayama, Makoto Ohta, Teiji Tominaga

    不明 120-121 2012年9月

  212. Computational fluid dynamic analysis following recurrence of cerebral aneurysm after coil embolization. 国際誌 査読有り

    Keiko Irie, Hitomi Anzai, Masahiko Kojima, Naomi Honjo, Makoto Ohta, Yuichi Hirose, Makoto Negoro

    Asian journal of neurosurgery 7 (3) 109-15 2012年7月

    DOI: 10.4103/1793-5482.103706  

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    Hemodynamic factors are thought to play important role in the initiation, growth, and rupture of cerebral aneurysms. However, hemodynamic features in the residual neck of incompletely occluded aneurysms and their influences on recanalization are rarely reported. This study characterized the hemodynamics of incompletely occluded aneurysms that had been confirmed to undergo recanalization during long-term follow-up using computational fluid dynamic analysis. A ruptured left basilar-SCA aneurysm was incompletely occluded and showed recanalization during 11 years follow-up period. We retrospectively characterized on three-dimensional MR angiography. After subtotal occlusion, the flow pattern, wall shear stress (WSS), and velocity at the remnant neck changed during long-term follow-up period. Specifically, high WSS region and high blood flow velocity were found near the neck. Interestingly, these area of the remnant neck coincided with the location of aneurysm recanalization. High WSS and blood flow velocity were consistently observed near the remnant neck of incompletely occluded aneurysm, prone to future recanalization. It will suggest that hemodynamic factors may play important roles in aneurismal recurrence after endovascular treatment.

  213. The Design Characteristics Extracted From an Optimal Flow Diverter in an Ideal Side-wall Aneurysm Using Lattice Boltzmann Method

    Hitomi Anzai, Jean-Luc Falcone, Bastien Chopard, Makoto Ohta

    不明 2012年7月

  214. PIV Measurement of Inflow through Cerebral Aneurysmal Neck of PVA-H Biomodel with Compliant Wall

    Shuya Shida, Makoto Ohta

    不明 2012年7月

  215. 細径光ファイバ圧力センサを用いた灌流圧測定機能を有する臓器灌流カテーテル

    引地広介, 松永忠雄, 早津幸弘, 佐藤充, 深谷昌宏, 飯沼貴章, 太田信, 齋木佳克, 芳賀洋一

    第51回日本生体医工学会大会論文集 51st 2012年5月

  216. 未破裂脳動脈流の破裂リスクに関する3次元可視化システムを用いたCFD解析の試み 招待有り 査読有り

    入江 恵子, 太田 信, 安西 眸, 廣瀬 雄一

    日本脳神経CI学会論文 33 (2) 119-125 2012年2月

  217. Preface

    Ohta, M., Hayase, T.

    Journal of Biomechanical Science and Engineering 7 (SPECIALISSUE.3) 197-197 2012年

  218. 3F0948 黄色ブドウ球菌の2成分性膜孔形成毒素の分子機構(膜蛋白質,口頭発表)

    Tanaka Yoshikazu, Yamashita Daichi, Yamashita Keitaro, Kawai Yuka, Kaneko Jun, Tomita Noriko, Ohta Makoto, Kamio Yoshiyuki, Yao Min, Tanaka Isao

    生物物理 52 S66 2012年

    出版者・発行元:一般社団法人 日本生物物理学会

    DOI: 10.2142/biophys.52.S66_3  

  219. Hemodynamic Study for New Stent Design with Mesh-Typed Stents in a Cerebral Aneurysm Model using PIV 査読有り

    Yu, Chang-Ho, Ohta, Makoto, Kwon, Tae-Kyu, IEEE

    2012 12th International Conference on Control, Automation and Systems (Iccas) 2012年

  220. DEVELOPMENT OF A METHODOLOGY FOR ADAPTATION OF REFRACTIVE INDEX UNDER CONTROLLING KINEMATIC VISCOSITY FOR PIV 査読有り

    Shida, Shuya, Kosukegawa, Hiroyuki, Ohta, Makoto, ASME

    Proceedings of the Asme International Mechanical Engineering Congress and Exposition 2011, Vol 2 2012年

  221. CONTROL OF WALL THICKNESS OF BLOOD VESSEL BIOMODEL MADE OF POLY (VINYL ALCOHOL) HYDROGEL BY A THREE-DIMENSIONAL-ROTATING SPIN DIP-COATING METHOD 査読有り

    Kosukegawa, Hiroyuki, Kiyomitsu, Chihaya, Ohta, Makoto, ASME

    Proceedings of the Asme International Mechanical Engineering Congress and Exposition 2011, Vol 2 2012年

  222. QUANTITATIVE ANALYSIS OF SUBUNIT MISMATCH ARRANGEMENT IN STAPHYLOCOCCAL GAMMA-HEMOLYSIN HETEROHEPTAMERIC TRANSMEMBRANE PORE 査読有り

    Tomita, Noriko, Abe, Kazuyo, Ohta, Makoto, ASME

    Proceedings of the Asme International Mechanical Engineering Congress and Exposition 2011, Vol 2 IMECE2011 63645 2012年

  223. Optimization of flow diverters for cerebral aneurysms 査読有り

    Anzai, Hitomi, Ohta, Makoto, Falcone, Jean-Luc, Chopard, Bastien

    Journal of Computational Science 3 (1-2) 1-7 2012年

    DOI: 10.1016/j.jocs.2011.12.006  

  224. Membrane-damaging activity against various phospholipid liposomes by γ-hemolysin, staphylococcal two-component pore-forming cytolysin 査読有り

    Noriko Tomita, Yoshiyuki Kamio, Makoto Ohta

    Journal of Biomechanical Science and Engineering 7 (3) 292-304 2012年

    DOI: 10.1299/jbse.7.292  

    ISSN:1880-9863

  225. Observation of the expansion behavior and quantitative evaluation of elastic recoil of a balloon-expandable stent in three dimensions using a Micro-CT system. 国際誌 査読有り

    Futoshi Mori, Toshio Nakayama, Teruo Matsuzawa, Makoto Ohta

    Technology and health care : official journal of the European Society for Engineering and Medicine 20 (4) 305-15 2012年

    DOI: 10.3233/THC-2012-0680  

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    Percutaneous transluminal coronary angioplasty (PTCA) with stent implantation is widely used for the treatment of coronary stenosis. However, restenosis after stent implantation frequently reported by intravascular ultrasound evaluation. This may occur because of the reduced luminal area after implantation, insufficient stent expansion, or by the elastic recoil of the stent (ERS). Quantitative evaluation of stent expanding should provide further information on how to decrease the incidence of re-stenosis. Many previous studies have observed stent properties in 2D. However, the stent geometry is changed in 3D space, and 3D measurements will provide further information on factors such as the risk for asymmetric ERS. We performed 3D reconstruction using high spatial resolution images obtained with a Micro-CT system to observe the 3D expansion behavior of a test stent and quantitatively evaluate ERS. The expansion behavior of each structural component of the stent varied, as did the ERS and eccentricity. ERS ranged from 2.4% to 9.2% during observation form proximal and distal positions in each component. The greatest difference in ERS between 2D and 3D measurements was 5.2%. 3D measurements provide more information on ERS than 2D measurements. Our result shows the importance of the observation, and the evaluation by three dimensions.

  226. A steady flow analsys on a cerebral aneurysm model with several stents for new stent design using PIV 査読有り

    Yu, Chang-Ho, Matsumoto, Kaoru, Shida, Shuya, Kim, Dong Joon, Ohta, Makoto

    Journal of Mechanical Science and Technology 26 (5) 1333-1340 2012年

    DOI: 10.1007/s12206-012-0322-x  

  227. A Cyper-Physical System for Strain Measurements in the Cerebral Aneurysm Models 査読有り

    Shi, Chaoyang, Kojima, Masahiro, Tercero, Carlos, Anzai, Hitomi, Ohta, Makoto, Ooe, Katsutoshi, Ikeda, Seiichi, Fukuda, Toshio, Arai, Fumihito, Negoro, Makoto, Irie, Keiko, Kwon, Guiryong, IEEE, Robotics Society of Japan

    2012 Ieee/rsj International Conference on Intelligent Robots and Systems (Iros) IROS 2012 4137-4142 2012年

    DOI: 10.1109/IROS.2012.6385754  

  228. Detection of Microcalcification in Soft Tissue Employing B-Flow ”Twinkling” Sign

    L. Liu, K. Ozawa, K. Funamoto, M. Ohta, T. Hayase, M. Ogasawara

    Proceedings of the 11th International Symposium on Advanced Fluid Information and Transdisciplinary Fluid Integration (AFI/TFI-2011) 94-95 2011年11月10日

  229. Cluster-forming property correlated with hemolytic activity by staphylococcal γ-hemolysin transmembrane pore 国際誌 査読有り

    Noriko Tomita, Kazuyo Abe, Yoshiyuki kamio, Makoto Ohta

    FEBS Letters 585 (21) 3452-6 2011年11月4日

    DOI: 10.1016/j.febslet.2011.09.041  

  230. Crystal structure of the octameric pore of staphylococcal γ-hemolysin reveals the β-barrel pore formation mechanism by two components 国際誌 査読有り

    Keitaro Yamashita, Yuka Kawai, Yoshikazu Tanaka, Nagisa Hirano, Jun Kaneko, Noriko Tomita, Makoto Ohta, Yoshiyuki Kamio, Min Yao, Isao Tanaka

    Proceedings of the National Academy of Sciences of the United States of America 108 (42) 17314-9 2011年10月18日

    DOI: 10.1073/pnas.1110402108  

  231. Computational fluid dynamics of carotid arteries after carotid endarterectomy or carotid artery stenting based on postoperative patient-specific computed tomography angiography and ultrasound flow data. 国際誌 査読有り

    Hitoshi Hayase, Koji Tokunaga, Toshio Nakayama, Kenji Sugiu, Ayumi Nishida, Seiji Arimitsu, Tomohito Hishikawa, Shigeki Ono, Makoto Ohta, Isao Date

    Neurosurgery 68 (4) 1096-101 2011年4月

    DOI: 10.1227/NEU.0b013e318208f1a0  

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    BACKGROUND: There are significant differences in the postoperative morphological and hemodynamic conditions of the carotid arteries between carotid artery stenting (CAS) and endarterectomy (CEA). OBJECTIVE: To compare the postoperative rheological conditions after CAS with those after CEA with patch angioplasty (patch CEA) through the use of computational fluid dynamics (CFD) based on patient-specific data. METHODS: The rheological conditions in the carotid arteries were simulated in 2 patients after CAS and in 2 patients after patch CEA by CFD calculations. Three-dimensional reconstruction of the carotid arteries was performed with the images obtained with computed tomography angiography. The streamlines and wall shear stress (WSS) were calculated by a supercomputer. Adequate boundary conditions were determined by comparing the simulation results with ultrasound flow data. RESULTS: CFD was successfully calculated for all patients. The differences between the flow velocities of ultrasound data and those of the simulation results were limited. In the streamline analysis, the maximum flow velocities in the internal carotid artery after patch CEA were around two-thirds of those after CAS. Rotational slow flow was observed in the internal carotid artery bulb after patch CEA. WSS analysis found regional low WSS near the outer wall of the bulb. High WSS was observed at the distal end of the arteriotomy after patch CEA and at the residual stenosis after CAS. CONCLUSION: CFD of postoperative carotid arteries disclosed the differences in streamlines and WSS between CAS and patch CEA. CFD may allow us to obtain adequate rheological conditions conducive to achieving the best clinical results.

  232. PIV measured hemodynamic study with several stents in a cerebral aneurysm model for new stent design 査読有り

    Chang-Ho Yu, Shuya Shida, Kaoru Matsumoto, Makoto Ohta

    ASME-JSME-KSME 2011 Joint Fluids Engineering Conference, AJK 2011 1 (D) 2073-2080 2011年

    DOI: 10.1115/AJK2011-19025  

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    The rupture of an aneurysm can lead to a subarachnoid hemorrhage, which can be a fatal illness in a large percentage of cases. In treating aneurysm intravascular stenting is thought as a better option compared with clipping treatment. The treatment of cerebral aneurysm with a porous stent also has recently proposed as a minimally invasive way to prevent rupture and favor coagulation mechanism inside aneurysm. The analysis of a flow pattern with and without stent in cerebral aneurysm model was performed with Particle Image Velocimetry (PIV). Three types of stents were used in the present investigation and the porosity of stent 1, 2 and 3 is 80%, 74% and 64 %, respectively. Reduced velocity, smaller average vorticity magnitude and different flow patterns inside aneurysm are observed when the three different proposed stents are used. The stent 3 (Porosity =64%) decrease the magnitude of the velocity by 98% and change the flow pattern in the aneurysm. Our results show that not only the role of the porosity but also the stent shape affect the flow and help us understand the characteristic of stent designs. Copyright © 2011 by ASME.

  233. Experimental analysis on MR fluid channel flow dynamics with complex fluid-wall interactions 査読有り

    Nishiyama, Hideya, Takana, Hidemasa, Shinohara, Keisuke, Mizuki, Kotoe, Katagiri, Kazunari, Ohta, Makoto

    Journal of Magnetism and Magnetic Materials 323 (10) 2011年

    DOI: 10.1016/j.jmmm.2010.11.033  

  234. Friction properties of PVA-H/steel ball contact under water lubrication conditions 査読有り

    Mamada, Keisuke, Kosukegawa, Hiroyuki, Fridrici, Vincent, Kapsa, Philippe, Ohta, Makoto

    Tribology International 44 (7-8) 757-763 2011年

    DOI: 10.1016/j.triboint.2010.12.014  

  235. Friction Properties of Poly(vinyl alcohol) Hydrogel: Effects of Degree of Polymerization and Saponification Value 査読有り

    Mamada, Keisuke, Fridrici, Vincent, Kosukegawa, Hiroyuki, Kapsa, Philippe, Ohta, Makoto

    Tribology Letters 42 (2) 2011年

    DOI: 10.1007/s11249-011-9768-8  

  236. Probabilistic Study on Subunit Mismatch Arrangement in Staphylococcal γ-hemolysin Heteroheptameric Transmembrane Pore 査読有り

    Noriko TOMITA, Kazuyo ABE, Jun KANEKO, Yoshiyuki KAMIO, Makoto OHTA

    Journal of Biomechanical Science and Engineering 6 (4) 286-298 2011年

    DOI: 10.1299/jbse.6.286  

    ISSN:1880-9863

  237. 黄色ブドウ球菌γヘモリジンが形成するヘテロヘプタマー膜孔複合体の立体構造予測と分子配置解析 招待有り 査読有り

    冨田典子, 安西眸, 安部和代, 太田信

    顕微鏡 45 (4) 223-228 2010年12月

    ISSN:1349-0958

  238. 多機能なカテーテル評価のためのPVA-Hモデルを用いた循環路システムの開発 査読有り

    橋田 葉子, 小助川 博之, 信太 宗也, 斉木 佳克, 松永 忠雄, 戸津 健太郎, 芳賀 洋一, 太田 信

    日本人工臓器学会 39 (2) 58 2010年11月18日

    ISSN:0300-0818

  239. Detection of Microcalcification in Soft Tissue

    L. Liu, M. Ogasawara, K. Ozawa, K. Funamoto, M. Ohta, T. Hayase

    Proceedings of the tenth International Symposium on Advanced Fluid Information and Transdisciplinary Fluid Integration (AFI/TFI-2010) 80-81 2010年11月2日

  240. 管内MR流体流動における壁面相互作用に関する基礎特性

    西山秀哉, 高奈秀匡, 篠原圭介, 水木琴絵, 片桐一成, 太田信

    日本レオロジー学会第58回レオロジー討論会講演要旨集 312-313 2010年10月6日

  241. 3P012 黄色ブドウ球菌γヘモリジンが形成するヘテロヘプタマー膜孔複合体におけるサブユニット配置解析(蛋白質-構造,第48回日本生物物理学会年会)

    Tomita Noriko, Abe Kazuyo, Anzai Hotomi, Ohta Makoto

    生物物理 50 (2) S146-S147 2010年

    出版者・発行元:一般社団法人 日本生物物理学会

    DOI: 10.2142/biophys.50.S146_6  

  242. Jet-Fluid Effects on the Stented-Flow Structure in the Cavity of Cerebral Aneurysm 査読有り

    Hirabayashi, Miki, Ohta, Makoto, Kojima, Hiroaki, Oiwa, Kazuhiro, Ruefenacht, Daniel A., Chopard, Bastien

    Biophysical Journal 98 (3) 2010年

    DOI: 10.1016/j.bpj.2009.12.2194  

  243. Development of an in vitro tracking system with poly (vinyl alcohol) hydrogel for catheter motion 査読有り

    ChangHo YU, Hiroyuki Kosukegawa, Keisuke Mamada, Kanju Kuroki, Kazuto Takashima, Kiyoshi Yoshinaka, Makoto Ohta

    Journal of Biomechanical Science and Engineering 5 (1) 11-17 2010年

    DOI: 10.1299/jbse.5.11  

    ISSN:1880-9863

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    Vascular diseases, such as ischemic heart disease, infarction, aneurysms, stroke and stenosis are a leading cause of serious long-term disability and their mortality rate is as high as that of cancers in many countries. Recently, neurovascular intervention using catheters is a minimally-invasive endovascular technique used to treat vascular disease of the brain, and a navigation system for catheters has been developed to facilitate surgical planning and to provide intra-operative assistance. Since the mechanical properties of a catheter play an important role in reaching the targeted disease, tracking of catheter movement during endovascular treatment may be useful to increase confirmation of the rate of successful operation. In this study, we developed an in vitro tracking system for catheter motion using poly (vinyl alcohol) hydrogel (PVA-H) to mimic an arterial wall. The employed models were made of PVA-H, which is sufficiently transparent to permit observation of catheter movement in the artery. This system is expected to contribute to validation of computer-based navigation systems for surgical assistance. © 2010 by JSME.

  244. Anisotropic In Vitro Vessel Model Using Poly(vinyl Alcohol) Hydro Gel and Mesh Material 査読有り

    Liu, Lei, Kosukegawa, Hiroyuki, Ohta, Makoto, Hayase, Toshiyuki

    Journal of Applied Polymer Science 116 (4) 2242-2250 2010年

    DOI: 10.1002/app.31687  

  245. Two-Dimensional Optimization of a Stent for an Aneurysm 査読有り

    Srinivas, K., Townsend, S., Lee, C. J., Nakayama, T., Ohta, M., Obayashi, S., Yamaguchi, T.

    Journal of Medical Devices-Transactions of the Asme 4 (2) 021003-1-021003-7 2010年

    DOI: 10.1115/1.4001861  

  246. DEVELOPMENT OF STENT STRUT PATTERN FOR CEREBRAL ANEURYSM 査読有り

    Nakayama, Toshio, Jeong, Shinkyu, Karkenahalli, Srinivas, Ohta, Makoto, ASME

    Proceedings of the Asme Fluids Engineering Division Summer Conference - 2010 - Vol 1, Pts a-C FEDSM/ICNMM 2010 30592 2010年

  247. MECHANICAL PROPERTIES OF TUBE-SHAPED POLY (VINYL ALCOHOL) HYDROGEL BLOOD VESSEL BIOMODEL 査読有り

    Kosukegawa, Hiroyuki, Shida, Shuya, Hashida, Yoko, Ohta, Makoto, ASME

    Proceedings of the Asme Fluids Engineering Division Summer Conference - 2010 - Vol 1, Pts a-C FEDSM/ICNMM 2010 30892 2010年

  248. THE EFFECT OF 3D VISUALIZATION ON OPTIMAL DESIGN FOR STRUT POSITION OF INTRACRANIAL STENT 査読有り

    Anzai, Hitomi, Nakayama, Toshio, Takeshima, Yuriko, Ohta, Makoto, ASME

    Proceedings of the Asme Fluids Engineering Division Summer Conference - 2010 - Vol 1, Pts a-C FEDSM/ICNMM 2010 30591 2010年

  249. Vertebrobasilar junction fenestration with dumbbell-shaped aneurysms formation: computational fluid dynamics analysis. 国際誌 査読有り

    Yuang-Seng Tsuei, Yasushi Matsumoto, Makoto Ohta, Toshio Nakayama, Masayuki Ezura, Akira Takahashi

    Surgical neurology 72 Suppl 2 S11-9-19 2009年12月

    DOI: 10.1016/j.surneu.2009.05.026  

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    BACKGROUND: We report 8 rare cases of paired ANs involving fenestrated vertebrobasilar junction and demonstrate the flow patterns of the paired ANs by qualitative CFD analysis in 5 cases. METHODS: Two-dimensional and 3-dimensional angiographic features of 8 cases were reviewed. Nine patient-specific geometries of CFD models in 5 cases were created for flow analysis. RESULTS: All 8 cases had 2 ANs, one large and the other small, projecting to the opposite sides at the proximal end of fenestrated vertebrobasilar junction. The different angiographic findings between right VA and left VA suggested the different hemodynamic characteristics of the respective VAs. Computational fluid dynamics analysis also demonstrated that the inflows of these paired ANs were different between right VA and left VA. Flow simulations by CFD were consistent with angiographic findings. CONCLUSION: Intrinsic wall defects at fenestrated vertebrobasilar junction and specific hemodynamic stresses from 2 inflows may contribute to the formation of a pair of dumbbell-shaped ANs.

  250. 生体材料を活用した管内MR流体流動の動的応答と高機能化

    篠原圭介, 水木琴絵, 片桐一成, 高奈秀匡, 太田信, 西山秀哉

    日本混相流学会年会講演会2009講演論文集 116-117 2009年8月7日

  251. 3TA5-05 黄色ブドウ球菌の2成分性毒素γヘモリジンが形成するヘテロヘプタマー膜孔複合体の立体構造解析(蛋白質-構造,第47回日本生物物理学会年会)

    Tomita Noriko, Anzai Hitomi, Kaneko Jun, Kamio Yoshiyuki, Ohta Makoto

    生物物理 49 S58-S59 2009年

    出版者・発行元:一般社団法人 日本生物物理学会

    DOI: 10.2142/biophys.49.S58_5  

  252. Evaluation of Compliance of Poly (vinyl alcohol) Hydrogel for Development of Arterial Biomodeling 査読有り

    Kosukegawa, H., Mamada, K., Kuroki, K., Liu, L., Inoue, K., Hayase, T., Ohta, M.

    13th International Conference on Biomedical Engineering, Vols 1-3 23 2009年

  253. Catheter and guidewire simulator for intravascular surgery (Comparison between simulation results and medical images) 査読有り

    Takashima, K., Ohta, M., Yoshinaka, K., Mukai, T., Oota, S.

    World Congress on Medical Physics and Biomedical Engineering, Vol 25, Pt 6 25 2009年

  254. 3D Observation of Expansion of Stent and Elastic Recoil using Micro-CT 査読有り

    Mori, Futoshi, Nakayama, Toshio, Matsuzawa, Teruo, Ohta, Makoto

    World Congress on Medical Physics and Biomedical Engineering, Vol 25, Pt 6 25 2009年

  255. Methodologies to assess blood flow in cerebral aneurysms: Current state of research and perspectives 査読有り

    Augsburger, L., Reymond, P., Fonck, E., Kulcsar, Z., Farhat, M., Ohta, M., Stergiopulos, N., Ruefenacht, D. A.

    Journal of Neuroradiology 36 (5) 270-277 2009年

    DOI: 10.1016/j.neurad.2009.03.001  

  256. Heat diffusion characteristics of magnetite nanoparticles dispersed hydro-gel in alternating magnetic field 査読有り

    Suto, Makoto, Kosukegawa, Hiroyuki, Maruta, Kaoru, Ohta, Makoto, Tohji, Kazuyuki, Jeyadevan, Balachandran

    Journal of Magnetism and Magnetic Materials 321 (20) 3483-3487 2009年

    DOI: 10.1016/j.jmmm.2009.06.067  

  257. Anisotropic Hybrid Blood Vessel Model using Poly (Vinyl Alcohol) Hydro Gel and Mesh Material

    Lei Liu, Hiroyuki Kosukegawa, Makoto Ohta, Toshiyuki Hayase

    GPBE/NUS-Tohoku Graduate Student Conference in Bioengineering 19-20 2008年12月

  258. 頸部内頸動脈狭窄症におけるCEAとCAS術後の医用画像を用いた患者特異的モデルと仮想モデルの流体力学シミュレーション

    早瀬 仁志, 中山 敏男, 徳永 浩司, 杉生 憲志, 西田 あゆみ, 有光 帥二, 菱川 朋人, 小野 成紀, 太田 信, 伊達 勲

    JNET: Journal of Neuroendovascular Therapy 2 (4) 297-297 2008年11月

    出版者・発行元:(NPO)日本脳神経血管内治療学会

    ISSN:1882-4072

    eISSN:2186-2494

  259. 頸部頸動脈狭窄症 CEA vs CAS 頸動脈狭窄症に対するステント留置術と内膜剥離術 治療成績、術後の頸動脈形状、血流速度およびcomputational flow dynamicsの比較検討

    徳永 浩司, 杉生 憲志, 早瀬 仁志, 有光 帥二, 菱川 朋人, 西田 あゆみ, 小野 成紀, 中山 敏男, 太田 信, 伊達 勲

    日本脳神経外科学会総会CD-ROM抄録集 67回 2E-08 2008年10月

    出版者・発行元:(一社)日本脳神経外科学会

    ISSN:1347-9040

  260. Frictional characteristics of erythrocytes on coated glass plates subject to inclined centrifugal forces. 国際誌 査読有り

    Takashi Kandori, Toshiyuki Hayase, Kousuke Inoue, Kenichi Funamoto, Takanori Takeno, Makoto Ohta, Motohiro Takeda, Atsushi Shirai

    Journal of biomechanical engineering 130 (5) 051007-051007 2008年10月

    DOI: 10.1115/1.2948420  

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    In recent years a diamond-like carbon (DLC) film and a 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer have attracted attention as coating materials for implantable artificial organs or devices. When these materials are coated on vascular devices, compatibility to blood is an important problem. The present paper focuses on friction characteristics of erythrocytes to these coating materials in a medium. With an inclined centrifuge microscope developed by the authors, observation was made for erythrocytes moving on flat glass plates with and without coating in a medium of plasma or saline under the effect of inclined centrifugal force. Friction characteristics of erythrocytes with respect to these coating materials were then measured and compared to each other to characterize DLC and MPC as coating materials. The friction characteristics of erythrocytes in plasma using the DLC-coated and noncoated glass plates are similar, changing approximately proportional to the 0.5th power of the cell velocity. The cells stick to these plates in saline as well, implying the influence of plasma protein. The results using the MPC-coated plate in plasma are similar to those of the other plates for large cell velocities, but deviate from the other results with decreased cell velocity. The results change nearly proportional to the 0.75th power of the cell velocity in the range of small velocities. The results for the MPC-coated plate in saline are similar to that in plasma but somewhat smaller, implying that the friction characteristics for the MPC-coated plate are essentially independent of plasma protein.

  261. Measurements of Dynamic Viscoelasticity of Poly(vinyl alcohol) Hydrogel for the Development of Blood Vessel Biomodeling 査読有り

    Hiroyuki Kosukegawa, Keisuke Mamada, Kanju Kuroki, Lei Liu, Kosuke Inoue, Toshiyuki Hayase, Makoto Ohta

    Journal of Fluid Science and Technology 3 (4) 533-543 2008年6月

    出版者・発行元:The Japan Society of Mechanical Engineers

    DOI: 10.1299/jfst.3.533  

    ISSN:1880-5558

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    <i>In vitro</i> blood vessel biomodeling with realistic mechanical properties and geometrical structures is helpful for training in surgical procedures, especial those used in endovascular treatment. Poly (vinyl alcohol) hydrogel (PVA-H), which is made of Poly (vinyl alcohol) (PVA) and water, may be useful as a material for blood vessel biomodeling due to its low surface friction resistance and good transparency. In order to simulate the mechanical properties of blood vessels, measurements of mechanical properties of PVA-H were carried out with a dynamic mechanical analyzer, and the storage modulus (G') and loss modulus (G") of PVA-H were obtained. PVA-Hs were prepared by the low-temperature crystallization method. They were made of PVA with various concentrations (C) and degrees of polymerization (DP), and made by blending two kinds of PVA having different DP or saponification values (SV). The G' and G" of PVA-H increased, as the C or DP of PVA increased, or as the proportion of PVA with higher DP or SV increased. These results indicate that it is possible to obtain PVA-H with desirable dynamic viscoelasticity. Furthermore, it is suggested that PVA-H is stable in the temperature range of 0°C to 40°C, indicating that biomodeling made of PVA-H should be available at 37°C, the physiological temperature. The dynamic viscoelasticity of PVA-H obtained was similar to that of the dog blood vessel measured in previous reports. In conclusion, PVA-H is suggested to be useful as a material of blood vessel biomodeling.

  262. Paramater Study of Hemodynamics Simulation at Internal Carotid Stenosis 査読有り

    Toshio Nakayama, Hitoshi Hayase, Koji Tokunaga, Makoto Ohta

    Journal of Fluid Science and Technology 3 (4) 544-552 2008年6月

    出版者・発行元:The Japan Society of Mechanical Engineers

    DOI: 10.1299/jfst.3.544  

    ISSN:1880-5558

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    Background and purpose: Stenting is one of the treatment options for carotid artery stenosis. To show the effectiveness of the treatment, computational fluid dynamics (CFD) has been performed for the last several decades. The inlet/outlet boundary conditions are important in CFD, and several researchers have used various inlet/outlet boundary conditions. In this paper, we compared the blood flow with various inlet/outlet boundary conditions and the measurement data obtained by an ultrasound device.<br>Methods: Blood flow speed was measured in the internal carotid artery (ICA), the external carotid artery (ECA), and the common carotid artery (CCA) using an ultrasound device. A carotid artery was reconstructed by computed tomography (CT). Mesh in the integrated data was generated to perform flow dynamics using a commercial code. CFD for blood flow was performed using the reconstructed carotid artery. Five cases of inlet and outlet boundary conditions (I/O B.C.) were used for the CFD. The simulation results were compared with the ultrasound data on the blood flow speed in the vicinity of the center of the ICA and the ECA.<br>Results: Various blood flow speeds were obtained from the five cases. The case of adjustment of pressures in ICA and ECA is the nearest flow speed to the ultrasound data.<br>Conclusion: The flow speed depends on the I/O B.C.. The I/O B.C. may be necessary for the measurement data obtained by ultrasound device or magnetic resonance imaging (MRI).

  263. Subtracted vortex centers path line method with cinematic angiography for measurement of flow speed in cerebral aneurysms. 国際誌 査読有り

    Makoto Ohta, Naoko Fujimura, Luca Augsburger, Krisztina Barath, Hasan Yilmaz, German Abdo, Karl-Olof Lovblad, Daniel A Rüfenacht

    Neurological research 30 (3) 251-5 2008年4月

    DOI: 10.1179/016164107X230658  

    ISSN:0161-6412

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    BACKGROUND AND PURPOSE: The assessment of blood flow speed by imaging modalities is of increasing importance for endovascular treatment, such as stent implantation, of cerebral aneurysms. The subtracted vortex centers path line method (SVC method) utilizes image post-processing for determining flow quantitatively. In current practice, intra-aneurysmal flow in an in vitro model is visualized by laser sheet translumination and digitally recorded. In this study, we applied this method to cinematic angiography (CA), which is the preferred imaging method for endovascular interventions, to analyse hemodynamic changes. The SVC method was applied to the images and compared with results of the slipstream line method with colored fluid. METHODS: A transparent tubular model was constructed of silicone which included an aneurysm 10 mm in diameter and having a 5 mm neck on a straight parent artery with a diameter of 3.5 mm. The model was integrated into a pulsatile circulation system. By CA, successive images at 25 frames/s with injection of contrast were obtained. RESULTS AND CONCLUSION: Rotating vortexes of contrast, which advanced along the wall of the aneurysm, were observed in successive images of the aneurysm cavity. This phenomenon was also observed in the successive images with the slipstream line method. The speed of the vortex center was calculated and the results show that the vortex speed of CA was the same as that under the slipstream line method. This indicates the possibility of applying the SVC method to medical imaging equipment for analysis of the flow in aneurysms containing stent.

  264. Accuracy Verification of Ultrasonic Measurement for Ultrasonic-Measurement-Integrated Simulation Using Poly (vinyl alcohol) Hydrogel Straight Tube Phantom

    Lei Liu, Toshiyuki Hayase, Makoto Ohta, Kosuke Inoue

    5th International Symposium on Global COE Program Global Nano-Biomedical Engineering Education and Research Network Centre 103-106 2008年3月

  265. Development of a catheter and guidewire simulator for interventional therapy 査読有り

    Kazuto Takashima, Shinzo Ota, Makoto Ohta, Kiyoshi Yoshinaka, Toshiharu Mukai

    日本バイオレオロジー学会誌(B&R) 22 (1) 1-7 2008年2月

    DOI: 10.11262/jpnbr1987.22.1_12  

  266. Studies on Design Optimization of Coronary Stents 査読有り

    Srinivas, K., Nakayama, T., Ohta, M., Obayashi, S., Yamaguchi, T.

    Journal of Medical Devices-Transactions of the Asme 2 (1) 2008年

    DOI: 10.1115/1.2885145  

  267. Experimental Validation of Color Doppler Velocity Measurement for Ultrasonic-Measurement-Integrated Simulation of Blood Flow 査読有り

    Lei Liu, Toshiyuki Hayase, Makoto Ohta, Kosuke Inoue

    Journal of Biomechanical Science and Engineering 3 (2) 161-175 2008年

    DOI: 10.1299/jbse.3.161  

    ISSN:1880-9863

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    Cardiovascular diseases are closely related to blood flow. Ultrasonic-Measurement-Integrated (UMI) simulation, in which results of ultrasonic measurement are fed back to the flow simulation, was proposed in a previous study in order to reproduce the real blood flow accurately and efficiently. The usability of the UMI simulation was confirmed by numerical experiment, but the effectiveness of this simulation was strongly affected by the accuracy of the ultrasonic measurement. In this paper, we examined the accuracy of a commercial ultrasonic measurement device by an experiment with a PVA-H straight tube phantom. By analyzing the measured color Doppler images for a developed laminar flow inside the phantom, we obtained the relationship between the color Doppler value and the Doppler velocity (C-V relationship). It was revealed that the original C-V relationship provided in the device as a color bar was not suitable for quantitative evaluation of Doppler velocity to be used in UMI simulation. Compared with the original C-V relationship, the present C-V relationship results are in far better agreement with the analytic solution. Investigation of the normalized error confirmed that the result obtained with the present C-V relationship was reliable in cases of relatively high Reynolds number in the flow domain except near the wall. The two signal conditioning factors of the device had little influence on the Doppler velocity. Finally, we investigated the effect of temporal and spatial averaging of ultrasonic measurement data to clarify the relation between the number of averagings and the level of agreement with the analytic solution. © 2008, The Japan Society of Mechanical Engineers. All rights reserved.

  268. Three-dimensional reconstruction of a cerebral stent using micro-CT for computational simulation 査読有り

    Ohta, Makoto, He, Chuan, Nakayama, Toshio, Takahashi, Akipa, Ruefenacht, Daniel A.

    Journal of Intelligent Material Systems and Structures 19 (3) 313-318 2008年

    DOI: 10.1177/1045389X07083184  

  269. Reproducibility of haemodynamical simulations in a subject-specific stented aneurysm model - A report on the Virtual Intracranial Stenting Challenge 2007 査読有り

    Radaellia, A. G., Augsburger, L., Cebral, J. R., Ohta, M., Ruefenacht, D. A., Balossino, R., Benndorf, G., Hose, D. R., Marzo, A., Metcalfe, R., Mortier, P., Mut, F., Reymond, P., Socci, L., Verhegghe, B., Frangi, A. F.

    Journal of Biomechanics 41 (10) 2069-2081 2008年

    DOI: 10.1016/j.jbiomech.2008.04.035  

  270. Micro-Computed Tomography Intracranial Angiography in Rat 査読有り

    Chuan He, Makoto Ohta, Masayuki Ezura, Akira Takahashi

    Proceedings of The Seventh International Symposium on Advanced Fluid Information and The Fourth International Symposium on Transdisciplinary Fluid Integration 44-46 2007年12月

  271. Parameter Study of Hemodynamics Simulation at Internal Carotid Stenosis 査読有り

    Toshio NAKAYAMA, Hitoshi HAYASE, Koji TOKUNAGA, Makoto Ohta

    Proceedings of The Seventh International Symposium on Advanced Fluid Information and The Fourth International Symposium on Transdisciplinary Fluid Integration 3 (4) 48-49 2007年12月

    出版者・発行元:The Japan Society of Mechanical Engineers

    DOI: 10.1299/jfst.3.544  

    ISSN:1880-5558

    詳細を見る 詳細を閉じる

    Background and purpose: Stenting is one of the treatment options for carotid artery stenosis. To show the effectiveness of the treatment, computational fluid dynamics (CFD) has been performed for the last several decades. The inlet/outlet boundary conditions are important in CFD, and several researchers have used various inlet/outlet boundary conditions. In this paper, we compared the blood flow with various inlet/outlet boundary conditions and the measurement data obtained by an ultrasound device.<br>Methods: Blood flow speed was measured in the internal carotid artery (ICA), the external carotid artery (ECA), and the common carotid artery (CCA) using an ultrasound device. A carotid artery was reconstructed by computed tomography (CT). Mesh in the integrated data was generated to perform flow dynamics using a commercial code. CFD for blood flow was performed using the reconstructed carotid artery. Five cases of inlet and outlet boundary conditions (I/O B.C.) were used for the CFD. The simulation results were compared with the ultrasound data on the blood flow speed in the vicinity of the center of the ICA and the ECA.<br>Results: Various blood flow speeds were obtained from the five cases. The case of adjustment of pressures in ICA and ECA is the nearest flow speed to the ultrasound data.<br>Conclusion: The flow speed depends on the I/O B.C.. The I/O B.C. may be necessary for the measurement data obtained by ultrasound device or magnetic resonance imaging (MRI).

  272. Measurement of Mechanical Properties of Poly (vinyl alcohol) Hyrdogel for Development of Blood Vessel Biomodeling 査読有り

    Hiroyuki KOSUKEGAWA, Keisuke MAMADA, kanju KUROKI, Lei LIU, Kosuke INOUE, Toshiyuki HAYASE, Makoto Ohta

    Proceedings of The Seventh International Symposium on Advanced Fluid Information and The Fourth International Symposium on Transdisciplinary Fluid Integration 50-51 2007年12月

  273. カテーテルシミュレータの開発 : 第2報, ガイドワイヤのトルク伝達性の評価

    高嶋 一登, 大田 慎三, 太田 信, 葭仲 潔, 向井 利春

    日本機械学会論文集. C編 73 (735) 2988-2995 2007年11月25日

    出版者・発行元:一般社団法人日本機械学会

    DOI: 10.1299/kikaic.73.2988  

    ISSN:0387-5024

    詳細を見る 詳細を閉じる

    We have developed catheter simulation system in blood vessels for surgical planning and intraoperative assistance. In this study, we evaluated the torquability of the guidewire model for the simulation system. The model of the guidewire is constructed with viscoelastic springs and segments as the dynamic deformation of a flexible structure. The vessel is an elastic circular cylinder, whose shape is defined by the centerline and the radii. Collisions between the guidewire and the vessel are calculated and the contact forces are determined according to the stiffness and friction of the vessel wall. Using these models, the trajectory of the guidewire tip was calculated when the proximal part of the guidewire model was twisted at a constant speed. When the friction coefficient between the guidewire and the vessel is large, the guidewire tip vibrates. When the guidewire is twisted, there is a lag before the guidewire tip starts rotating and friction obstructs this rotation. Besides the friction coefficient, the shape of the blood vessel also affects the motion of the guidewire tip. When the guidewire becomes stiffer, the torquability of guidewire tip increases. This simulator would be useful for the analysis of the structure of the guidewire and may help guide the design of new guidewire.

  274. ステントによる脳動脈瘤内血流の減少シミュレーション 査読有り

    太田信, 小助川博之, 間々田圭祐, 奥野健二郎, 黒木完樹, 中山敏男

    第29回日本バイオマテリアル学会大会予稿集 55 2007年11月

  275. ネックにおけるステントデザインがおよぼす脳動脈瘤内の血行動態への影響 招待有り 査読有り

    中山敏男, 太田信, 奥野健二郎, 高橋明, ダニエルルフナハト

    第23回日本脳神経血管内治療学会総会 プログラム抄録集 140 2007年11月

  276. Micro-Computed Tomography Intracranial Angiography in Rat 招待有り 査読有り

    HeChuan 太田信, 江面正幸, 高橋明

    第23回日本脳神経血管内治療学会総会 プログラム抄録集 224 2007年11月

  277. Dumbell aneurysm formation involving unfused BA on vertebrobasilar junction:Experience of 8cases with computational flow dynamics analysis 査読有り

    TsueiYuang-Seng, 松本康史, 太田信, 中山敏男, 江面正幸, 高橋明

    第23回日本脳神経血管内治療学会総会 プログラム抄録集 231 2007年11月

  278. Investigation of heat diffusion characterisitics of magnetic nanoparticles in AC magnetic field 招待有り 査読有り

    M.SUTO, K.MARUTA, M.OHTA, H.KOSUKEGAWA, R.J.JOSEYPHUS, K.TOHJI, B.JAYADEVAN

    5th International Workshop on WATER DYNAMICS 61 2007年9月

  279. マイクロCTを用いたラットの脳血管3次元再構築 招待有り 査読有り

    太田信, 中山敏男, 何川 高橋明

    日本機械学会2007年度 年次大会講演論文集 6 (No.07-1) 95-96 2007年9月

  280. Poly(vinyl alcohol)hydrogelを用いた力学的特性を付与した血管モデルの開発 査読有り

    小助川博之, 間々田圭祐, 劉磊, 黒木完樹, 早瀬敏幸太田信

    第36回医用高分子シンポジウム 講演要旨集 81-82 2007年7月

  281. Effest of Stenting Rotational Positions on Hemodynamics in a Cerebral Aneurysm

    Nakayama,T. Ohta, M. Rufenachat, D.A. Takahashi,A

    AMERICAN SOCIETY OF NEURORADIOLOGY 2007: PROCEEDINGS 158 2007年6月

  282. Cinematic Angiography for Assesments of blood Flow in Cerebral Aneurysm with Stents 査読有り

    Ohta,M. Fujimura, N. Augsburger, L. Barath, K. Yilmaz, H Abdo,G. Ruefenachat,D.A

    AMERICAN SOCIETY OF NEURORADIOLOGY 2007: PROCEEDINGS 315-316 2007年6月

  283. 力学特性を付与した脳動脈瘤モデル開発のための,Poly(vinyl alcohol)hydrogelの物性評価 招待有り 査読有り

    小助川博之, 間々田圭祐劉磊, 黒木完樹, 早瀬敏幸太田信

    第30回日本バイオレオロジー学会年会 21 69 2007年6月

  284. 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 招待有り 査読有り

    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年5月

    出版者・発行元:The Japan Society of Acupuncture and Moxibustion

    DOI: 10.3777/jjsam.57.110  

    ISSN:0285-9955

    詳細を見る 詳細を閉じる

    本シンポジウムでは、手首の橈骨動脈の脈状から内臓臓器の機能を知るということは可能かという設問に対して、さまざまな立場の専門家が見解を述べた。小川は脈診の臨床的意義を明らかにするためには、脈診の診断法としての再現性と、その証に基づく治療が臨床医学的観点からより有効であることの証明が必要とした。木戸は脈診トレーニング法を紹介し、それに基づく臨床試験の試みから、脈診の診断・治療上の意義を明らかにした。丸山は、圧センサを用いた脈波情報の計測と数値モデル解析による脈診の客観化の試みを紹介し、その限界とともに将来の客観化の可能性に言及した。智原は、脈診で用いられる橈骨動脈で検出される圧脈波のもつ意味について、病態生理学的観点を交えてさまざまな可能性を示し、その情報が全身状態を反映する可能性を認めながらも、その対応は1 : 1ではないことを指摘した。最後に脈診に関する実験的検討の必要性が確認された。

  285. 交流磁場中における磁性ナノ粒子の熱拡散の数値シミュレーションおよび実験的検討 査読有り

    須藤誠, 小助川博之, 丸田薫, 太田信, 田路和幸, Balachandran Jeyadevan

    日本機械学会 第19回「電磁力関連のダイナミクス」シンポジウム 98-100 2007年5月

  286. The Effect to Hemodynamics of an Intracranial Aneurysm by a Difference of Stent Struct Design 招待有り 査読有り

    Toshio Nakayama, Makoto Ohta, Daniel A.Rufenachat, Akira Takahashi

    The 4th International Intracranial Stent Meeting 35-36 2007年4月

  287. Optimisation of Stents for Aneurysm 招待有り 査読有り

    K. Srinivas, M Ohta, T. Nakayama, S. Obayashi, T. Yamaguchi

    The 4th International Intracranial Stent Meeting ICS07 PROGRAM&ABSTRACTS 38 2007年4月

  288. Studies on Funstional Biomodeling of Cerebral Artery with Mechanical Properties using Poly (vinyl alcohole) Hydro-gel 査読有り

    Hiroyuki KOSUKEGAWA, Keisuke MAMADA, Lei LIU, Kanju KUROKI, Toshiyuki HAYASE, Makoto OHTA

    The 4th International Intracranial Stent Meeting ICS07 PROGRAM&ABSTRACTS 39-40 2007年4月

  289. 脳動脈瘤内の血流に対するステントデザインの影響 査読有り

    中山敏男, 太田信, Daniel A. Rufenachat, 高橋明

    題46回 日本生体医工学大会 生体医工学 45 PS1-6-6 2007年4月

  290. 傾斜遠心顕微鏡による皮膜基盤上の赤血球の摩擦特性計測 査読有り

    神取 孝司, 井上 浩介, 早瀬 敏幸, 高木 敏行, 竹野 貴法, 太田 信, 武田 元博

    日本機械学会東北支部 第42期総会・講演会 111-112 2007年3月

  291. シネマティックアンギオグラフィにオプティカルフロー法を適用した血流の定量測定法開発 査読有り

    恩田 一寿, 太田 信

    日本機械学会東北支部第42期総会・講演会 115-116 2007年3月

  292. 脈診の数値モデル構築のための基礎的研究 査読有り

    鳴海 賢太郎, 中西 勉, 劉 磊, 白井 敦, 早瀬 敏幸, 太田 信, 金野 敏, 川田 浩, 丸山 満也, 仁田 新一

    日本機械学会東北支部第42期総会・講演会 121-122 2007年3月

  293. In-vitro model of artery based on Poly vinyl alcohol (PVA) hydrogel (PVA-H) with low friction 招待有り 査読有り

    Makoto Ohta

    The 4th LYON-TOHOKU ENGINEERING & SCIENCE FORUM 23 2007年2月

  294. Bio-tribology of a catheter/biomodel vessel contact 招待有り

    Makoto Ohta

    The 4th LYON-TOHOKU ENGINEERING & SCIENCE FORUM 71 2007年2月

  295. The Effect of Stenting with Difference Positions on Hemodynamics in a Cerebral Aneurysm 査読有り

    Toshio Nakayama, Makoto Ohta, Daniel A.Rufenachat, Akira Takahashi

    The 9th International Symposium on Future Medical Engineering Based on Bio-nanotechnology 106-107 2007年1月

  296. 実形状ステントを設置した脳動脈瘤内の血流シミュレーション 査読有り

    中山 敏男, 太田信, 信 Daniel A.Rufenachat, 高橋 明

    第19回 バイオエンジニアリング講演会 講演論文集 84-85 2007年1月

  297. Cinematic Angiography for Measurements of blood Flow in Cerebral Aneurysm with Stents 査読有り

    太田 信

    Proceedings of FEDSM2007 5th Joint ASME/JSME Fluids Engineering Conference FEDSM2007-37254 FEDSM2007-37254 (CD-ROM) 1-6 2007年

    DOI: 10.1115/FEDSM2007-37254  

  298. Micro-Computed Tomography Selective Intracranial Vascular Angiography in Rat

    He, C, Ohta, M, Nakayama, T, Takahashi, A

    The 2nd Tohoku-NUS Joint Symposium on the Future Nano-medicine and Bioengineering in the East Asian Region 91-92 2006年12月

  299. Application of Ultrasonic Measurement to PVA-H Tissue-mimicking phantom

    Liu L, Inoue, K, Hayase, T, Ohta, M

    The 2nd Tohoku-NUS Joint Symposium on the Future Nano-medicine and Bioengineering in the East Asian Region 97-98 2006年12月

  300. Fundamental Study ofUltrasonic-Mesurement-Integrated Simulation: Numerical Experimant and Experimantal Applicatin with PVA Straight Pipe Model 査読有り

    Lei LIU, Kosuke INOUE, Toshiyuki HAYASE, Makoto OHTA

    Proceedings of the 6th International Symposium on Advanced Fluid Information, 53-54 2006年12月

  301. 血管内カテーテルシミュレータに関する基礎研究(第2報,接触力算出方法の評価)

    高嶋一登, 大田慎三, 太田 信, 葭仲潔, 向井利春

    第17回バイオフロンティア講演会講演論文集 6 (46) 49-50 2006年11月

  302. 脈診における脈派情報の取得に関する数学モデルの構築と実験による検証

    鳴海賢太郎, 中西勉, 劉磊, 井上浩介, 白井敦, 早瀬敏幸, 太田信, 金野敏, 川田浩, 丸山満也, 白石泰之, 仁田新一

    第17回バイオフロンティア講演会講演論文集 6 (46) 55-56 2006年11月

  303. ステントの3次元形状データを用いた動脈瘤内の血流シミュレーション

    中山敏男, 太田 信, Rüfenacht, DA, 高橋 明

    第22回日本脳神経血管内治療学会総会 157 2006年11月

  304. 3次元PIVデータによる脳内速度分布の定量的解析

    村上洋紀, 太田 信, 早瀬敏幸, 加藤琢真, 小杉隆司, 礒田治夫

    第22回に本能神経血管内治療学会 157 2006年11月

  305. Numerical Simulation of Hemodynamics in Cerebral Arterial Aneurysm using Realistic Stent Data 査読有り

    Nakayama, T, Ohta, M, Rüfenacht, DA, Takahashi, A

    the 6th International Symposium on Advanced Fluid Information 47-48 2006年10月

  306. 脳動脈瘤の3次元形状計測分析

    太田 信, Rüfenacht DA

    流体工学部門講演会 講演概要集 06 (21) 110 2006年10月

  307. 3-D Reconstruction of a Cerebral Stent Using micro-CT for Computational Simulation 査読有り

    Ohta, M, He C, Nakayama, T, Takahashi, A, Rüfenacht DA

    International Joing Conference of INABIO/SMEBA 2006 97 2006年9月

  308. Three dimensional measurements of cerebral Aneurysms and vessel size 査読有り

    Ohta, M, Lachenal. Y, Augsburger, G, Abdo, G, Yilmaz, H, Fujimura, N, Babic, D, Lylyk, P, Rüfenacht, DA

    Journal of Biomechanics 39S1 S364 2006年8月

  309. カテーテルシミュレータの開発 査読有り

    高嶋 一登, 大田 慎三, 太田 信, 葭 仲 潔, 池内 健

    日本機械学会論文集 72 (719) 2006年7月

    DOI: 10.1299/kikaic.72.2137  

  310. Three Diamensions Image of Cerebral Vascular for computational Fluid Dynamics in rat: feasibility of assessment with Micro-CT 査読有り

    He, C, Nakayama, T, Ohta, M, Takahashi, A

    the Third International Symposium on Transdisciplinary Fluid Integration 59-60 2006年6月

  311. Scion Imageをもちいたコントラスト比較法による4D-CT movieの評価

    石田藤麿, 梅田靖之, 亀井祐介, 岡田昌彦, 太田 信, 鈴木秀典, 滝 和郎

    第35回日本神経放射線学会 122 2006年2月

  312. 血管内カテーテルシミュレータに関する基礎研究 招待有り

    高嶋一登, 大田慎三, 太田信, 信, 葭仲, 潔, 池内 健

    第18回バイオエンジニアリング講演会 講演論文集 05-66 355-356 2006年1月12日

  313. Three dimensional imaging of cerebral vasculature for computer fluid dynamics in rat: Feasibility of assessment with micro-CT 査読有り

    He, Chuan, Takahashi, Akira, Nakayama, Toshio, Ohta, Makoto

    Future Medical Engineering Based on Bionanotechnology, Proceedings 2006年

    DOI: 10.1142/9781860948800_0099  

  314. Numerical realization of blood flow in aneurysmal aorta by integrating measurement and simulation 査読有り

    Hayase, Toshiyuki, Funamoto, Kenichi, Yamagata, Takayuki, Liu, Lei, Shirai, Atsushi, Ohta, Makoto, Inoue, Kosuke, Saijo, Yoshifumi, Yambe, Tomoyuki

    Future Medical Engineering Based on Bionanotechnology, Proceedings 2006年

    DOI: 10.1142/9781860948800_0092  

  315. Experimental validation of Ultrasonic-Measurement-Integrated Simulation for blood flow in aorta 査読有り

    Liu, Lei, Inoue, Kosuke, Hayase, Toshiyuki, Ohta, Makoto

    Future Medical Engineering Based on Bionanotechnology, Proceedings 2006年

    DOI: 10.1142/9781860948800_0105  

  316. Scion Imageをもちいたコントラスト比較法による4D-CT movieの評価

    石田藤麿, 梅田靖之, 亀井祐介, 岡田昌彦, 太田 信, 鈴木秀典, 滝 和郎

    第35回日本神経放射線学会 122 2006年

  317. 血管内カテーテルシミュレータに関する基礎研究

    高嶋一登, 大田慎三, 太田信, 信, 葭仲, 潔, 池内 健

    第18 回バイオエンジニアリング講演会 講演論文集 05-66 355-356 2006年1月

  318. Numerical analysis of the flow pattern in stented aneurysms and its relation to velocity reduction and stent efficiency 査読有り

    Hirabayashi, Miki, Ohta, Makoto, Barath, Krisztina, Ruefenacht, Daniel A., Chopard, Bastien

    Mathematics and Computers in Simulation 72 (2-6) 128-133 2006年

    DOI: 10.1016/j.matcom.2006.05.037  

  319. Method to quantify flow reduction in aneurysmal cavities of lateral wall aneurysms produced by stent implants used for flow diversion 査読有り

    Fujimura, N, Ohta, M, Abdo, G, Ylmaz, H, Lovblad, KO, Rufenacht, DA

    Interventional Neuroradiology 12 (S1) 197 2006年

    DOI: 10.1177/15910199060120S135  

  320. Development of fundamental technologies with use of in-vitro and in-silico models for endovascular treatments 招待有り 査読有り

    Daniel A. Rüfenacht, Pedro Lylyk, Toshiyuki Hayase

    Proceedings of the fifth international symposium on advanced fluid information - IFS-JAXA joint symoposium- 32-33 2005年12月8日

  321. Development of a functional vessel biomodelling with Poly (vinyl alcohol) Hydrogel for in-vitro simulation 査読有り

    Lei Liu, Kousuke Inoue, Toshiyuki Hayase, Akira Handa, Edouard Fonck, Fumio Asakura, Stephan G. Wetzel, German Abdo, Hasan Yilmaz, Karl-Olof. Lovblad, Luca Augsburger, Daniel A. Rüfenacht, Hiroo Iwata, Suong-Hyu Hyon, Sadami Tsutsumi

    The 6th international symposium on future medical engineering based on Bio-nanotechnology (21st Century COE program) 31-32 2005年11月21日

  322. cinematic angiography を用いた脳動脈瘤内の血流測定法の開発(第2報) 査読有り

    藤村直子, アウグスブルガールカ, フォンクエドワード, イルマスハッサン, アブドヘルマン, バラスクリスティーナ, ラブブラッドカールオロブ, ルフナハトダニエル

    第21回日本脳神経血管内治療学会総会 132 2005年11月

  323. PVAによる,チューブ型脳動脈瘤バイオモデリングの開発 査読有り

    藤村直子, 劉磊, アウグスブルガールカ, フォンクエドワード, ルフナハトダニエル, 高橋明, 岩田博夫, 堤 定美

    第21回日本脳神経血管内治療学会総会 216 2005年11月

  324. モデルを用いた、脳動脈瘤内の血流変化におけるステントの影響

    藤村直子, Luca, Augsburger, Stephan Wetzel, Hasan Yimaz, German Abdo, Karl-Olof Lobvled, Krisztina Barath, Daniel, A. Ruefenacht

    日本隆太入来学会年会2005 講演論文集 224-224 2005年9月

  325. Cinematic Angiography を用いた脳動脈瘤内の血流測定法の開発 査読有り

    藤村直子, 岩田博夫, 堤 定美, ルフナハトダニエル

    2005年度年次大会講演論文集 5 87-88 2005年9月

  326. Numerical simulations of flow changes induced by insertion of flow diverter in idealized models of cerebral aneurysms: a parametrical study 招待有り 査読有り

    L. Augsburger, E Fonck, M Ohta, DA Rufenacht, N Stergiopulos

    swiss society for biomedical engineering F02-F02 2005年9月1日

  327. PVAによる、In-vitro 脳動脈瘤モデルの開発

    太田 信, 劉 磊, 早瀬 敏幸, 半田 明, RUFENACHT D. A., 岩田 博夫, 堤 定美

    日本バイオレオロジー学会年会抄録集 28 (s) 36-36 2005年6月30日

  328. Transdisciplinary Methodology Integrating Measurement and Simulation in Application of Complex Biomedical Flows

    Toshiyuki Hayase, Kenichi Funamoto, Takayuki Yamagata, Lei Liu, Atsushi Shirai, Makoto Ohta, Kosuke Inoue, Yoshifumi Saijo, Tomoyuki Yambe

    Proceedings of the 5th International Symposium on Advanced Fluid information (AFI-2005) 36-39 2005年

  329. Measurement of elastic properties of blood vessels 査読有り

    D. Ilic, T. Moix, O. Lambercy, L. Sache, H. Bleuler, M. Ohta, L. Augsburger

    2005 27th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, Vols 1-7 0-7803-8740 6199-6202 2005年

    出版者・発行元:IEEE

    ISSN:1094-687X

    詳細を見る 詳細を閉じる

    This paper is related to the measurements of the modulus of elasticity of an artery by studying the deformations due to the inflation of an angioplasty balloon catheter used for Interventional Radiology (IR) procedures. Various types of balloons are studied in order to characterize and compare their behaviors at the time of inflation. A test bench, consisting of an angioplasty balloon, a Polyvinyl alcohol model and an actuator used to inflate a balloon, is developed for the realization of the experiments. The pressure-volume curve during the inflation of a balloon is observed. Elasticity modulus are derived with an analytical model of the measurement system. The results are then analyzed and compared to existing data from literature.

  330. Measurement of internal constraints during.an interventional radiology procedure 査読有り

    D. Ilic, I. Moix, O. Lambercy, L. Sache, H. Bleuler, M. Ohta, L. Augsburger

    2005 27TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY, VOLS 1-7 0-7803-8740 2615-2618 2005年

    出版者・発行元:IEEE

    ISSN:1094-687X

    詳細を見る 詳細を閉じる

    This paper presents a novel method for measurements of internal constraints during an Interventional Radiology procedure. Fiber-optic strain gauge, operating as a Fabry-Perot interferometer, is inserted and navigated inside a polyvinyl alcohol (PVA) model. The information obtained from deformation of the Fabry-Perot cavity is analyzed and the results are then rescaled through a calibration procedure for catheters. The measures help to locate the maximum interaction forces between catheter and blood vessel wall at approximately 1.3 N and to observe the shape of dynamic interaction during manipulation.

  331. From patient to model: Stereolithographic modeling of the cerebral vasculature based on rotational angiography 査読有り

    Wetzel, SG, Ohta, M, Handa, A, Auer, JM, Lylyk, P, Lovblad, KO, Babic, D, Rufenacht, DA

    American Journal of Neuroradiology 26 (6) 1425-1427 2005年

  332. Influence of stent properties on the alteration of cerebral intra-aneurysmal haemodynamics: flow quantification in elastic sidewall aneurysm models. 国際誌 査読有り

    Krisztina Baráth, Francis Cassot, Jean H D Fasel, Makoto Ohta, Daniel A Rüfenacht

    Neurological research 27 Suppl 1 (1) S120-8-128 2005年

    DOI: 10.1179/016164105X35477  

    ISSN:0161-6412

    詳細を見る 詳細を閉じる

    OBJECTIVES: Stent implantation across the neck of cerebral aneurysms may induce intra-aneurysmal flow reduction, and consequently saccular thrombosis and vessel wall repair. To analyse the influence of different stent parameters on such flow reduction, we studied the flow changes in vascular models, induced by a series of stents. METHODS: Two different neck-sized elastic sidewall aneurysm models were connected to a circulatory loop. Twenty different stents were introduced in both models to analyse the effect of their parameters, such as porosity, filament diameter and permeability. Flow patterns were visualized by using glass particles and laser sheet translumination. The digitally recorded data were transferred for computer analysis. The changes of the vortex velocity for each stent model combination were investigated and statistically evaluated. RESULTS: Intra-aneurysmal flow analysis showed dispersion of the vortices of a variable degree, and velocity reduction of 30% mean in model 1 and 49% mean in model 2. By statistical analysis three groups of stents ('best', 'medium', 'worst') were identified, according to their haemodynamic efficacy. No correlations were observed between the haemodynamic performance of the stents and the porosity, filament diameter and permeability values separately. The stent effects were on average more important in the large-necked than in the small-necked aneurysm model. DISCUSSION: Stent implantation induces intra-aneurysmal loss of vortex coherence and flow reduction. The analysed stent parameters show complex interrelationship, including also stent 'design'. The difference in the haemodynamic efficacy of the individual stents between the two models raises the question of 'stent positioning effects'.

  333. Rheological changes after stenting of a cerebral aneurysm: A finite element modeling approach 査読有り

    Ohta, M, Wetzel, SG, Dantan, P, Bachelet, C, Lovblad, KO, Yilmaz, H, Flaud, P, Rufenacht, DA

    Cardiovascular and Interventional Radiology 28 (6) 768-772 2005年

    DOI: 10.1007/s00270-004-7148-6  

  334. Development of a polyvinyl alcohol hydrogel for temperature measurement by MRI. 国際誌 査読有り

    Makoto Ohta, J Paul Jacobson, Emile Hiltbrand, Alexis Kelekis, Marko Ivancevic, Daniel A Rüfenacht, Hiroo Iwata, Sadami Tsutsumi

    Technology and health care : official journal of the European Society for Engineering and Medicine 13 (4) 221-8 2005年

    ISSN:0928-7329

    詳細を見る 詳細を閉じる

    This paper describes the development of a Polyvinyl alcohol hydrogel (PVA-H) model for calibration and measurement of temperature using image contrast on MRI using DMSO/H_2O as a solvent to alter the freezing and melting points of PVA-H. Tissues exposed to temperature changes above 41 degrees C or below 0 degrees C exhibit increasingly extensive and irreversible damage, depending on the exposure duration. MR images can provide a map of temperature if there is sufficient tissue signal. To evaluate treatment principles using temperature changes (hyperthermia, cryotherapy), a model simulating tissue may be useful to provide a reproducible test environment. PVA-H is water soluble and can be seen on MRI. It can be used to construct complicated shapes such as vascular structure, soft tissues, and so on. Therefore, PVA-H can be useful to measure temperatures and assume the distribution of temperature under treatment. In this paper, we applied PVA-H as a temperature detector and calibrated temperature from image contrast. The results exhibit good capability as a temperature detector not only of high temperature (around 41 degrees C), but also of low temperature (as low as -23 degrees C).

  335. Current Concept of Endovascular Aneurysm Treatment and about the Role of Stents for Endovascular Repair of Cerebral Arteries 査読有り

    Daniel A. Rüfenacht, Makoto Ohta, Hasan Yilmaz, Carlos Miranda, Diego San Millan Ruiz, German Abdo, Pedro Lylyk

    Swiss Archives of Neurology and Psychiatry 155 (7) 348-352 2004年7月

  336. Impact of stent design on intra-aneurysmal flow - A computer simulation study 査読有り

    Ohta, M, Hirabayashi, M, Wetzel, S, Lylyk, P, Wata, H, Tsutsumi, S, Rufenacht, DA

    Interventional Neuroradiology 10 (Supp2) 85-94 2004年

    DOI: 10.1177/15910199040100S216  

  337. A lattice Boltzmann study of blood flow in stented aneurism 査読有り

    Hirabayashi, M, Ohta, M, Rufenacht, DA, Chopard, B

    Future Generation Computer Systems 20 (6) 925-934 2004年

    DOI: 10.1016/j.future.2003.12.004  

  338. Poly-vinyl alcohol hydrogel vascular models for in vitro aneurysm simulations: the key to low friction surfaces. 国際誌 査読有り

    Makoto Ohta, Akira Handa, Hiroo Iwata, Daniel A Rüfenacht, Sadami Tsutsumi

    Technology and health care : official journal of the European Society for Engineering and Medicine 12 (3) 225-33 2004年

    ISSN:0928-7329

    詳細を見る 詳細を閉じる

    PURPOSE: To develop a vessel model with poly-vinyl alcohol hydrogel (PVA-H) with low surface friction for in vitro simulations of vascular pathologies. MATERIALS AND METHODS: Simulations of variable vascular pathologies were based on human vessel casts reproduced in wax. Constructions of vascular models were then obtained by lost wax techniques. As materials, liquid silicon or PVA in organic solvents were used. After solidification, the wax was drained by heating. Comparison of PVA-H with silicone models included evaluation of surface characteristics (friction coefficient), of visibility (transparence and compatibility with medical imaging techniques), and of stiffness (pulsatility of vascular lumen). Both model types were integrated in a circulation circuit allowing for flow simulations and testing with endovascular medical devices. RESULTS AND CONCLUSION: Both model types were transparent and compatible with current medical imaging methods. PVA-H models exhibited much lower friction characteristics. PVA-H stiffness was closer to soft tissue when compared to silicone, allowing for pulsations during flow simulations.

  339. Characterization of flow reduction properties in an aneurysm due to a stent. 国際誌 査読有り

    Miki Hirabayashi, Makoto Ohta, Daniel A Rüfenacht, Bastien Chopard

    Physical review. E, Statistical, nonlinear, and soft matter physics 68 (2 Pt 1) 021918-021918 2003年8月

    DOI: 10.1103/PhysRevE.68.021918  

    ISSN:1539-3755

    詳細を見る 詳細を閉じる

    We consider a lattice Boltzmann simulation of blood flow in a vessel deformed by the presence of an aneurysm. Modern clinical treatments involve introducing a stent (a tubular mesh of wires) into the cerebral artery in order to reduce the flow inside the aneurysm and favor its spontaneous reabsorption. A crucial question is to design the stent with suitable porosity so as to produce the most effective flow reduction. We propose a stent positioning factor as a characterizing tool for stent pore design in order to describe the flow reduction effect and reveal the several flow reduction mechanisms using this effect.

  340. Lattice Boltzmann analysis of the flow reduction mechanism in stented cerebral aneurysms for the endovascular treatment 査読有り

    Hirabayashi, M, Ohta, M, Rufenacht, DA, Chopard, B

    Computational Science - Iccs 2003, Pt I, Proceedings 2657 2003年

    出版者・発行元:Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)

  341. Control of crystalline orientation to enhance the wear resistance of ultra-high molecular weight polyethylene crystallization cups for artificial joints 査読有り

    Ohta, M, Hyon, SH, Tsutumi, S

    Wear 255 (7-12) 1045-1050 2003年

    DOI: 10.1016/S0043-1648(03)00284-9  

  342. Wear properties of UHMWPE oriented under uniaxial compression during the molten state and at lower temperatures than the melting point 査読有り

    Ohta, M, Hyon, SH, Kang, YB, Oka, M, Tsutsumi, S, Murakami, S, Kohjiya, S

    Jsme International Journal Series C-Mechanical Systems Machine Elements and Manufacturing 46 (4) 1297-1303 2003年

    DOI: 10.1299/jsmec.46.1297  

  343. MRE を用いた剛性率と粘性率の計測

    大城 理, 菅 幹生, 太田 信, 松田 哲也, 堤 定美, 湊 小太郎, 千原 國宏, 高橋 隆

    Medical imaging technology 19 (5) 389-399 2001年9月25日

    出版者・発行元:日本医用画像工学会

    DOI: 10.11409/mit.19.389  

    ISSN:0288-450X

  344. Surface Modification of Manesium by NaHCO_3 and Corrosion Behavior in Hank's solution for New Biomaterial Applications

    Al-Abdullat Yousef, Tsutsumi Sadami, Nakajima Naoki, OHTA Makoto, KUWAHARA Hideyuki, IKEUCHI Ken

    Materials transactions 42 (8) 1777-1780 2001年8月20日

    出版者・発行元:公益社団法人 日本金属学会

    DOI: 10.2320/matertrans.42.1777  

    ISSN:1345-9678

    詳細を見る 詳細を閉じる

    The present study was carried out to improve the corrosion resistance of pure magnesium in Hank&rsquo;s Balanced Salt Solution (HBSS) through the surface modification. Three kinds of alkaline compounds, such as sodium hydrogen carbonate, sodium carbonate, and lithium hydroxide, were used for treatment. Only magnesium treated with aqueous sodium hydrogen carbonate solution gave a good corrosion resistance in HBSS solution at 25&deg;C up to 75 days, while almost no effect in sodium carbonate and lithium hydroxide. It was likely that hydrogen carbonate ions were essential for the surface improvement of magnesium. X-ray diffraction patterns of modified magnesium showed new peaks of magnesium carbonate and others on the surface. New surface structure of needle-shaped crystals was observed by scanning electron microscopy (SEM). Both elemental mapping, and energy dispersive (EDX) techniques in SEM showed the precipitation of calcium magnesium phosphate (low crystallinity whitlockite:(Ca,Mg)<SUB>3</SUB>(PO<SUB>4</SUB>)<SUB>2</SUB>) on the surface of magnesium specimen. It could be concluded that surface modification with sodium hydrogen carbonate made it possible to apply metal magnesium in biomedical, dental, and other industrial usage.

  345. Risk Factors and Predictors of Coronary Arterial Lesions in Japanese Hypertensive Patients

    KATO Junko, AIHARA Akiko, KIKUYA Masahiro, MATSUBARA Mitsunobu, OHTA Masahiro, OHKUBO Takayoshi, TSUJI Ichiro, SEKINO Hiroshi, MEGURO Taiichiro, IMAI Yutaka

    Hypertension research : clinical and experimental : official journal of the Japanese Society of Hypertension 24 (1) 3-11 2001年

    出版者・発行元:The Japanese Society of Hypertension

    DOI: 10.1291/hypres.24.3  

    ISSN:0916-9636

    詳細を見る 詳細を閉じる

    The morbidity rate of coronary artery disease has recently increased in Japan. This is attributable to changes from traditional to more westernized lifestyles. In this study, we therefore examined the risk factors and predictors of coronary arterial lesions in Japanese patients with essential hypertension. Coronary angiography was performed in 109 consecutive essential hypertension patients (57 men and 52 women; 66±8.0 years of age) with either angina pectoris or atypical chest pain, who were chosen from 485 consecutive hypertensive patients in a hypertension clinic in Sendai, Japan. Coronary arterial stenosis of greater than 50% was defined as significant and used as a dependent variable for the multiple regression analysis. Risk factors were defined as factors confirmed to have a causal relationship with coronary arterial lesions, whereas arteriosclerotic complications and hypertensive target organ damage were defined as predictors. Multiple logistic regression analysis was performed using these parameters as independent variables. Of 109 patients, 25 had a coronary arterial stenosis greater than 50%. A smoking habit (odds ratio (OR): 4.48; 95% confidence interval (CI): 1.13-17.82; p<0.05), hypercholesterolemia (OR: 5.34; 95% Cl: 1.52-18.73; <I>p</I><0.05), and 24-h diastolic blood pressure (OR: 2.33; 95% Cl: 1.06-5.16; <I>p</I><0.05) were significant risk factors, whereas carotid intima-media thickness (OR: 5.85; 95% Cl: 1.48-23.2; <I>p</I><0.05) was a significant predictor of coronary arterial lesion. When two of the major risk factors (a smoking habit, hypercholesterolemia, or impaired glucose tolerance including diabetes mellitus) were clustered in addition to the hypertension, the risk of coronary arterial lesions increased by 6.7 to 10.1 times. These findings indicate that the major risk factors established in Caucasians, I.e., a smoking habit, hypercholesterolemia and blood pressure level, are also risk factors for coronary arterial lesions in Japanese with essential hypertension. The presence of two or more risk factors increases the risk of coronary arterial lesions synergistically in the presence of hypertension. (Hypertens Res 2001; 24: 3-11)

  346. Residual Stress Measurements of Ultra-high Molecular Weight Polyethylene for Artificial Joints 査読有り

    Makoto Ohta, Sadami Tsutumi, Suong-Hyu Hyon, Yu-Bong Kang, Hirotaka Tanabe, Yoshio Miyoshi

    Russian J. Biomechanics 5 (2) 30-38 2001年

  347. Effect of the compression ratio on wear properties of slightly cross-linked ultra-high molecular weight polyethylene, crystallized under uniaxial compression 査読有り

    Ohta, M, Hyon, SH, Kang, YB, Murakami, S, Kohjiya, S, Oka, M, Tsutsumi, S

    Wear 250 (1-12) 145-151 2001年

    DOI: 10.1016/S0043-1648(01)00606-8  

  348. 圧縮配向結晶化超高分子量ポリエチレンの耐摩耗性と力学的性質

    太田 信, 玄 丞烋, 姜 有峯, 岡 正典, 堤 定美, 村上 昌三, コウジ谷 信三

    材料 49 (12) 1301-1305 2000年12月15日

    出版者・発行元:社団法人日本材料学会

    DOI: 10.2472/jsms.49.1301  

    ISSN:0514-5163

    詳細を見る 詳細を閉じる

    In order to improve the wear properties of artificial joints, a slightly cross-linked ultra high molecular weight polyethylene (UHMWPE) was compressed at molten state and crystallized by cooling to room temperature. The molecular chain of the UHMWPE was orientated to the direction of deformation. Density and melting point of the mold article were increased in accordance with compression ratio. The &alpha;<i><sub>c</sub></i> peak of loss modulus was shifted to higher temperature compared with the non-compressed sample. And it was also revealed that the weight loss of the compressed UHMWPE was remarkably less than that of a non-compressed sample from the result of the pin-on-disc wear test.

  349. 【Sensible Human Project】局所生体弾性率のMR Elastography法を用いた計測と評価 査読有り

    菅 幹生, 湊 小太郎, 松田 哲也, 大城 理, 千原 國宏, 太田 信, 堤 定美, 小森 優, 高橋 隆, 岡本 淳, 滝沢 修

    MEDICAL IMAGING TECHNOLOGY 18 (6) 769-776 2000年11月

    出版者・発行元:日本医用画像工学会

    ISSN:0288-450X

    詳細を見る 詳細を閉じる

    MR Elastography(MRE)法を用いることで弾性体内部を伝わる弾性波を画像化できる.弾性率は外部震動周波数,弾性体の密度及び弾性波の波長から計算できるため,MRE画像から局所波長を求めることで生体内の剛性率の分布を非侵襲的に測定できる.MRE画像から弾性率の局所分布を得るために,MRI装置内で駆動可能な加震システムと撮影シーケンスを開発し,初期位相の異なる複数のMRE画像を用いた局所波長計測手法を考案した.本システムの信頼性を検証するために,硬さの異なる複数の弾性体試料について物理的計測値との比較を行い,両者の結果がよく一致することを確認した.又,本手法を用いて,実際に生体組織の弾性係数を計測可能であることを示した

  350. 局所生体弾性率の MR Elastography 法を用いた計測と評価

    菅 幹生, 湊 小太郎, 松田 哲也, 大城 理, 千原 國宏, 太田 信, 堤 定美, 小森 優, 高橋 隆, 岡本 淳, 滝沢 修

    Medical imaging technology 18 (6) 769-776 2000年11月1日

    出版者・発行元:日本医用画像工学会

    DOI: 10.11409/mit.18.769  

    ISSN:0288-450X

  351. 圧縮配向結晶化による超高分子量ポリエチレン結晶の残留応力測定

    太田 信, 玄 丞烋, 姜 有峯, 岡 正典, 堤 定美, 田邊 裕貴, 三好 良夫

    日本臨床バイオメカニクス学会誌 = Proceedings of ... Annual Meeting of Japanese Society for Clinical Biomechanics and Related Research 21 319-322 2000年10月1日

    ISSN:1340-9018

  352. 超高速 MR Imaginngを用いた顎運動計測 招待有り 査読有り

    東高志, 南部敏之, 土肥健二, 太田信, 堤定美, 井上博志, 林浩二, 伊藤仁

    日本臨床バイオメカニクス学会論文集 21 489-495 2000年

  353. Surface reaction of magnesium in Hank's solutions 査読有り

    Kuwahara, H, Al-Abdullat, Y, Ohta, M, Tsutsumi, S, Ikeuchi, K, Mazaki, N, Aizawa, T

    Magnesium Alloys 2000 350-3 349-358 2000年

    DOI: 10.4028/www.scientific.net/MSF.350-351.349  

  354. 配向結晶化UHMWPEの耐摩耗性と力学的性質

    玄 丞烋, 太田 信, 堤 定美, 岡 正典

    日本臨床バイオメカニクス学会誌 = Proceedings of ... Annual Meeting of Japanese Society for Clinical Biomechanics and Related Research 20 293-296 1999年10月1日

    ISSN:1340-9018

  355. Methods to reduce the wear of ultrahigh-molecular-weight polyethylene 査読有り

    Oka, M, Hyon, SH, Ohta, M, Nakamura, T, Ushio, Y, Toguchida, J

    Joint Arthroplasty 1999年

  356. Dynamic modulus measurements of a lightly cross-linked ultra-high molecular weight polyethylene crystallized under uniaxial compression 査読有り

    Makoto Ohta, Suong-Hyu Hyon, Yu-Bong Kang, Sadami Tsutsumi, Masanori Oka, Syozo Murakami, Shinzo Kohjiya

    Russian Journal of Biomechanics 3 (4) 34-48 1999年

  357. Wear resistance of lightly cross-linked ultrahigh-molecular-weight polyethylene crystallized from the melt under uniaxial compression 査読有り

    Ohta, M, Hyon, SH, Oka, M, Tsutsumi, S

    Wear 225 (1-2) 312-318 1999年

    DOI: 10.1016/S0043-1648(99)00077-0  

  358. 人工歯根の振動特性に関する研究 招待有り 査読有り

    太田信, 村瀬晃平, 伊藤智恵, 堤定美

    日本臨床バイオメカニクス学会論文集 19 303-306 1998年

  359. 配向結晶化UHMWPEの耐摩耗性 査読有り

    玄丞烋, 太田信, 堤定美, 池内健, 岡正典

    日本臨床バイオメカニクス学会論文集 19 461-465 1998年

︎全件表示 ︎最初の5件までを表示

MISC 197

  1. A Review of Functional Analysis of Endothelial Cells in Flow Chambers

    Makoto Ohta, Naoya Sakamoto, Kenichi Funamoto, Zi Wang, Yukiko Kojima, Hitomi Anzai

    JOURNAL OF FUNCTIONAL BIOMATERIALS 13 (3) 2022年9月

    出版者・発行元:MDPI

    DOI: 10.3390/jfb13030092  

    eISSN:2079-4983

    詳細を見る 詳細を閉じる

    The vascular endothelial cells constitute the innermost layer. The cells are exposed to mechanical stress by the flow, causing them to express their functions. To elucidate the functions, methods involving seeding endothelial cells as a layer in a chamber were studied. The chambers are known as parallel plate, T-chamber, step, cone plate, and stretch. The stimulated functions or signals from endothelial cells by flows are extensively connected to other outer layers of arteries or organs. The coculture layer was developed in a chamber to investigate the interaction between smooth muscle cells in the middle layer of the blood vessel wall in vascular physiology and pathology. Additionally, the microfabrication technology used to create a chamber for a microfluidic device involves both mechanical and chemical stimulation of cells to show their dynamics in in vivo microenvironments. The purpose of this study is to summarize the blood flow (flow inducing) for the functions connecting to endothelial cells and blood vessels, and to find directions for future chamber and device developments for further understanding and application of vascular functions. The relationship between chamber design flow, cell layers, and microfluidics was studied.

  2. コイル塞栓術における脳血管内治療医の注視点の特徴と経験症例数との関係

    岡本吉弘, 庄島正明, 新妻邦泰, 太田信, 植松美幸, 迫田秀行, 配島由二

    人工臓器(日本人工臓器学会) 49 (2) 2020年

    ISSN:0300-0818

  3. マイクロセンサを搭載した脳血管モデル

    芳賀洋一, 芳賀洋一, 吉田洋, 松永忠雄, 清水康智, 太田信, 太田信, 庄島正明, 益田泰輔, Yu Kaihong, Simon Tupin, Dai Chenming, 新井史人, 原田香奈子

    電気学会論文誌 E 140 (12) 2020年

    ISSN:1341-8939

  4. 血管内治療デバイス留置シミュレータの開発(コイル接触力とカテーテルの動作の評価)

    大石卓弥, 高嶋一登, 葭中潔, YU Kaihong, 太田信, 森浩二, 当麻直樹

    日本機械学会バイオフロンティア講演会講演論文集(CD-ROM) 31st 2020年

    ISSN:1348-2939

  5. 変形を伴う中大脳動脈瘤内流れの挙動

    池谷直紀, 山崎智皓, 田中学, 太田信, 山口隆平

    日本機械学会バイオフロンティア講演会講演論文集(CD-ROM) 31st 2020年

    ISSN:1348-2939

  6. 4次元血管造影法に基づく脳底動脈瘤における血流挙動の数値解析

    山崎智皓, 岡崎陽大, 田中学, 太田信, 石田藤麿, 山口隆平

    日本機械学会バイオフロンティア講演会講演論文集(CD-ROM) 31st 2020年

    ISSN:1348-2939

  7. 6th International Conference on Computational and Mathematical Biomedical Engineering(CMBE2019)を開催して

    太田 信

    日本バイオレオロジー学会会報 33 (3) 124-124 2019年

    出版者・発行元:特定非営利活動法人 日本バイオレオロジー学会

    DOI: 10.11262/jpnbr.33.3_124  

    ISSN:0913-4778

    eISSN:2186-5663

  8. 弾性変形を伴う実脳動脈瘤内流れの挙動

    滝澤岳, 田中学, TUPIN Simon, 太田信, 山口隆平

    バイオエンジニアリング講演会講演論文集(CD-ROM) 32nd 2019年

    ISSN:2424-2829

  9. 脳動脈瘤コイル留置のシミュレーション-手法と応用例-

    高嶋一登, 当麻直樹, 太田信, 森浩二

    脳血管内治療(Web) 4 (Supplement) 2019年

    ISSN:2424-1709

  10. 脳動脈瘤コイル留置のシミュレーション-目的と課題-

    当麻直樹, 高嶋一登, 太田信, 森浩二

    脳血管内治療(Web) 4 (Supplement) 2019年

    ISSN:2424-1709

  11. MRA画像を用いた脳底動脈形状の標準化

    北村洸, 麦倉俊司, 太田信, 安西眸

    日本機械学会バイオフロンティア講演会講演論文集(CD-ROM) 30th 2019年

    ISSN:1348-2939

  12. PIVを用いた血管内視鏡周りのフラッシュ流れ解析

    三塚康平, TUPIN Simon, LI Yujie, 中山敏男, 太田信

    日本機械学会バイオフロンティア講演会講演論文集(CD-ROM) 30th 2019年

    ISSN:1348-2939

  13. バイオニックヒューマノイドプラットフォームと要素技術の成果

    益田 泰輔, 太田 信, 芳賀 洋一, 光石 衛, 原田 香奈子, 新井 史人, 小俣 誠二, 相原 一, 森田 明夫, 金 太一, 齊藤 延人, 山下 樹里, 鎮西 清行, 福田 敏男

    生体医工学 57 (0) S203_2-S203_2 2019年

    出版者・発行元:公益社団法人 日本生体医工学会

    DOI: 10.11239/jsmbe.Annual57.S203_2  

    ISSN:1347-443X

    詳細を見る 詳細を閉じる

    <p>我々はリアリティの高い人体シミュレータを実現し,手術トレーニングやデバイス評価環境を構築するために,生体と類似する物理特性を再現し,センサやアクチュエータと言った能動的な機能デバイスを組み込んだ人体シミュレータ「バイオニックヒューマノイド」を提案している.そのバイオニックヒューマノイドの構造および特徴を有するプラットフォームとして,眼科手術(Bionic-EyE:BE)・脳外科手術(Bionic-Brain:BB)・血管内手術(Bionic-Vasculature:BV)に対応したそれぞれの専用プラットフォームを開発した.ここでは,各プラットフォームの紹介と,数ミクロンレベルの内境界膜(ILM)剥離モデルの作製,ミクロン繊維の不織布とエラストマー材料を交互に積層させた線維柱体モデルの作製,鼻腔・下垂体周辺モジュールの作製,フレキシブル圧電センサによる手術手技評価などの各要素技術の成果について報告する.</p>

  14. Compliance effect on the flow condition in vascular in vitro experiments 査読有り

    Masami Matsuura, Simon Tupin, Makoto Ohta

    ASME 2018 International Mechanical Engineering Congress and Exposition IMECE2018 87362(1)--87362(7) 2018年11月

  15. Permeability studies for the improvement of medical devices

    Simon Tupin, Makoto Ito, Makoto Ohta

    15th ICFD (Internatinal Conference of Fluid Dynamics) 2018年11月

  16. Hemodynamic Study on Coronary Artery Aneurysms with Bypass Surgery

    Haoran Wang, Hitomi Anzai, Makoto Ohta, Youjun Liu

    15th ICFD (Internatinal Conference of Fluid Dynamics) 2018年11月

  17. Research on Arterial Stiffness in Type 2 Diabetic Patients Based on Pulse Wave Analysis

    Gaoyang Li, Xiaorui Song, Aike Qiao, Makoto Ohta

    15th ICFD (Internatinal Conference of Fluid Dynamics 2018年11月

  18. 3Dプリンタを用いたPVA‐H血管モデル作製用複合機の開発(第一報)

    長野凌太, 清水康智, 吉田洋, 松永忠雄, 葛迫淳一, 木原信宏, 芳賀洋一, 太田信

    日本シミュレーション外科学会会誌 26 (2) 127-127 2018年10月

    出版者・発行元:日本シミュレーション外科学会

    ISSN:1348-6918

  19. バイオニックヒューマノイドの開発と評価

    山下樹里, 原田香奈子, 太田信, 鎮西清行

    ヒューマンインタフェースシンポジウム論文集(CD-ROM) 2018 ROMBUNNO.7C2‐1 2018年9月5日

    ISSN:1345-0794

  20. PIV MEASUREMENT IN AN IDEAL ANEURYSMAL MODEL USING A TRANSPARENT COIL MODEL 査読有り

    Makoto OHTA, Masanori KUZE, Simon TUPIN, Kaihong YU, Yasutomo SHIMIZU, Hitomi ANZAI

    Conference on Modelling Fluid Flow (CMFF’18) 2018年7月

  21. Dose hypertension history affect morphology or hemodynamic characteristics of Cerebrobasilar System? Retrospetive study of 249 patients diagnosed with hypertension. 査読有り

    Yujie Li, Mingzi Zhang, Ko Kitamura, Hitomi anzai, Shuji Mugikura, Makoto Ohta

    8th World Congress of Biomechanics 2018年7月

  22. Characteristics of Elasticity on Flow Behavior in Middle Cerebral Aneurysm Model 査読有り

    Ryuhei Yamaguchi, Gaku Tanaka, Taihei Kotani, Kahar Osman, Nadia Shafii, Hitomi Anzai, Makoto Ohta

    8th World Congress of Biomechanics 2018年7月

  23. Drilling of PMMA-based bone biomodel: effect of temperature elevation during drilling 査読有り

    Yuta Muramoto, Gaëtan Bouvard, Vincent Fridrici, Philippe Kapsa, Fredrik Lundell, Makoto Ohta

    8th World Congress of Biomechanics 2018年7月

  24. Experimental analysis of AAA treatment by multi-layer stent and fate of abdominal aortic branches 査読有り

    Simon Tupin, Kei Takase, Makoto Ohta

    8th World Congress of Biomechanics 2018年7月

  25. Can morphology or haemodynamic characteristics of verteebrobasilar system be identifier of hypertension 査読有り

    Ko Kitamura, Yujie Li, Mingzi Zhang, Hitomi Anzai, Shuji Mugikura, Makoto Ohta

    8th World Congress of Biomechanics 2018年7月

  26. Multiobjective Optimization of Stent Design towards In-Stent Restenosis

    Narendra Kurnia Putra, Pramudita Satria Palar, Hitomi Anzai, Koji Shimoyama, Makoto Ohta

    8th World Congress of Biomechanics 2018年7月

  27. Design of fabrication machine for 3-dimensional hydrogel blood vessel biomodels

    Yasutomo Shimizu, Hiroshi Yoshida, Tadao Matsunaga, Yoichi Haga, Makoto Ohta

    8th World Congress of Biomechanics 2018年7月

  28. 格子ボルツマン法を用いたステントストラット配置が脳動脈瘤内流れに与える影響の解析

    渡邉 和浩, 安西 眸, 太田 信

    計算工学講演会論文集 Proceedings of the Conference on Computational Engineering and Science 23 4p 2018年6月

    出版者・発行元:日本計算工学会

    ISSN:1342-145X

  29. 脳動脈瘤抽出用ニューラルネットワークにおける,入力画像の表現方法の違いによる判定精度への影響

    渡邉和浩, 安西眸, JUCHLER Norman, HIRSCH Sven, BIJLENGA Philippe, 太田信

    バイオエンジニアリング講演会講演論文集(CD-ROM) 31st 2018年

    ISSN:2424-2829

  30. バイオニックヒューマノイド搭載のための血管モデルの開発

    清水 康智, 新井 史人, 原田 香奈子, 太田 信, 于 凱鴻, テュパン シモン, 吉田 洋, 松永 忠雄, 益田 泰輔, 金 太一, 庄島 正明, 芳賀 洋一

    ロボティクス・メカトロニクス講演会講演概要集 2018 (0) 1P1-J03 2018年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmermd.2018.1P1-J03  

    詳細を見る 詳細を閉じる

    <p>Blood vessel models for medical training have been developed to represent realistic geometries and mechanical properties of the realistic blood vessels. However, few models were developed for assembling the other organ models. The purpose of this study is to develop a new blood vessel model which can be mounted on the Bionic Humanoid. The geometries and the mechanical properties of realistic cerebral arteries were represented using poly (vinyl alcohol) hydrogel (PVA-H) and silicone. We observed the PVA-H model can be ruptured depending on the force on the catheters and the guidewires during operations. This result cannot be observed using the previous blood vessel models produced from silicone or the other materials, and this observation indicates the PVA-H model can represent the realistic situations in operations.</p>

  31. Fabrication, Observation and Tribological Characterization of Acrylic Composite Materials for Bone Biomodel for Surgical Drilling

    Yuta Muramoto, Gaëtan Bouvard, Makoto Ohta, Vincent Fridrici, Philippe Kapsa

    30ème Jornées Internationals Francophones de Tribologie (JIFT2018) 2018年

  32. バイオエンジニアリング部門:「脳神経血管内治療に関する医工学連携研究会(A-TS02-16)」の紹介(<小特集>脳神経血管内治療に関する医工学連携研究)

    太田 信, 高嶋 一登

    日本機械学会誌 121 (1197) 28-29 2018年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmemag.121.1197_28  

  33. 生体組織モデル工学のすすめ(<小特集>脳神経血管内治療に関する医工学連携研究)

    太田 信, 清水 康智

    日本機械学会誌 121 (1197) 30-30 2018年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmemag.121.1197_30  

  34. 183 ハイドロゲル製血管モデル造形用複合機プロトタイプの作製とその評価

    清水 康智, 吉田 洋, 松永 忠雄, 芳賀 洋一, 太田 信

    東北支部総会・講演会 講演論文集 2018 (0) 163-164 2018年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmeth.2018.53.163  

  35. 脳動脈血管PVA-Hモデルに対する官能評価

    于 凱鴻, TUPIN Simon, 庄島 正明, 太田 信

    バイオエンジニアリング講演会講演論文集 2018 (0) 2I02 2018年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebio.2018.30.2I02  

  36. 血管内治療デバイス留置シミュレータの開発:(コイルと動脈瘤モデルの接触状態の可視化)

    林田 典大, 鈴木 秀謙, 高嶋 一登, 葭仲 潔, 于 凱鴻, 太田 信, 森 浩二, 当麻 直樹, 佐野 貴則, 梅田 靖之

    バイオエンジニアリング講演会講演論文集 2018 (0) 2I05 2018年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebio.2018.30.2I05  

  37. Location related variability of permeability characteristics in cancellous bone

    Ito Makoto, Tupin Simon, Anzai Hitomi, Suzuki Anna, Ohta Makoto

    Proceedings of the 14th International Conference on Flow Dynamics 834-835 2017年11月

  38. 海綿骨内における浸透率測定

    伊藤誠, TUPIN Simon, 安西眸, 鈴木杏奈, 太田信

    日本バイオレオロジー学会誌(Web) 31 (2) 2017年

    ISSN:2186-5663

  39. 血管モデルの開発と動物実験

    太田信, 大西泰平, TUPIN Simon, 清水康智, 于凱鴻, 安西眸

    日本実験動物学会総会講演要旨集 64th 2017年

  40. 教育用,評価用,プレオペ用血管モデルの開発

    太田信, 清水康智, 于凱鴻, TUPIN Simon, 安西眸

    日本医学放射線学会秋季臨床大会抄録集 53rd 2017年

    ISSN:0048-0428

  41. 血管内治療デバイス留置シミュレータの開発:(血管バイオモデルを用いたコイルの変形挙動評価)

    林田 典大, 梅田 靖之, 高嶋 一登, 葭仲 潔, 于 凱鴻, 太田 信, 森 浩二, 当麻 直樹, 鈴木 秀謙, 佐野 貴則

    バイオエンジニアリング講演会講演論文集 2017 (0) 2B32 2017年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebio.2017.29.2B32  

  42. 流量計と圧力センサを組み込んだインビトロモデルによるマルチレイヤーステントの評価

    テュパン シモン, 清水 康智, 安西 眸, 太田 信

    バイオエンジニアリング講演会講演論文集 2017 (0) 2B34 2017年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebio.2017.29.2B34  

  43. バイオニックヒューマノイド妥当性評価と標準化の取り組み

    山下 樹里, 太田 信, 鎮西 清行

    年次大会 2017 (0) W241004 2017年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmemecj.2017.W241004  

    詳細を見る 詳細を閉じる

    <p>Recently, a wide variety of human organ simulators, such as virtual reality (VR) and 3D printed models, have been developed for medical education and for development of new medical equipment. Although expectations for such simulators to replace animal and human subjects are high, their validation and verification (V&V) processes are not clear yet. Our goal is to define "biofidelity" of organ models, that is the degree of their exactness to real organs with appropriate V&V processes. The result will be submitted to ISO as a new proposal.</p>

  44. マイクロ粒子を含有した超音波診断機器用モデルの開発

    高橋 廉, 山口 匡, 太田 信

    年次大会 2017 (0) J0240304 2017年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmemecj.2017.J0240304  

    詳細を見る 詳細を閉じる

    <p>Phantoms for ultrasonography have been widely used to improve skills of physicians and techniques of ultrasonic scattering. Several kinds of phantoms for ultrasonography have already been developed using gelatin, Polyacrylamide. In the development of biomodel for ultrasonography that covers human soft tissue, to change the mechanical properties widely is useful. We chose a poly (vinyl alcohol) hydrogel (PVA-H) to mimic human soft tissue. The purpose of this study is to measure the mechanical properties with varieties of concentration of solvent of PVA solution. The ratio of the mixed solution of Dimethyl sulfoxide (DMSO) and water was changed. The measurement of the static viscoelasticity, the dynamic viscoelasticity, and the loss tangent of PVA-H were performed. In addition, we measured the transverse wave velocity for the phantom to which graphite was added. In conclusion, the variety of mechanical properties of PVA-H is shown by the change of solvents, and especially the loss tangent is twice higher than the conventional PVA-H. And the transverse wave velocity has also a relation to the solvents.</p>

  45. ポーラスメディアモデルを用いたフローダイバータステント周りの血流数値解析

    李 玉潔, 張 明子, 銭 逸, 太田 信

    年次大会 2017 (0) J0230205 2017年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmemecj.2017.J0230205  

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    <p>Flow-diverting (FD) stent is a commonly adopted devices for the minimally-invasive treatment of intracranial aneurysm (IA). With a FD stent properly deployed across the aneurysm orifice, it may discourage the flow from entering the aneurysm, thereby reducing the chance of aneurysm rupture. Using computational fluid dynamics (CFD) method, the aneurysmal haemodynamcis can be resolved to observe the flow-diversion efficacy and estimate the condition of aneurysm. Modelling the FD stent as a porous medium (PM) in the simulation, as an alternative to the original fully-resolved wire FD stent, is discovered to be an useful and flexible method to obtain the flow-diversion efficacy with improved simulation efficiency. However, current simulations with PM model FD stent tend to define the properties of the PM with consistent value, which fail to represent the different flow resistance result from the specific wire configurations in each stent of interest. Therefore, in this study, we aim to investigate a set of parameters for the calibrated PM stent model to represent a variety of commercially available FD stents and different treatment modes. The sensitivity in flow-diversion effects was observed with regard to the designing of PM model thickness and parameter settings of the PM model properties. Results indicate that the PM model thickness has negligible influence to the aneurysmal haemodynamics as long as the flow resistance are compensated to be identical, while the definition of PM properties, such as the permeability (k) and inertial resistance factor (C2), can induce flow-diversion effects with marked difference.</p>

  46. フローダイバータステントを用いた脳動脈瘤治療に対する数値シミュレーションの応用

    張 明子, 李 玉潔, 安西 眸, 銭 逸, 太田 信

    年次大会 2017 (0) J0230204 2017年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmemecj.2017.J0230204  

    詳細を見る 詳細を閉じる

    <p>Intracranial aneurysms (IAs) account for a large portion of cerebrovascular disorders and can be treated with flow-diverting (FD) stents. To aid the treating clinicians with determination of a favourable treatment plan, we adopted numerical simulation methods to the optimisation of FD treatment, including the design optimisation of FD stent wire structure, as well as the optimisation of FD stent treatment procedure. Our simulation results suggest that both stent design and stent deployment may drastically affect the FD treatment outcomes; numerical simulation prior to the real treatment may therefore assist the treating clinicians in predicting the treatment outcomes.</p>

  47. バイオニックヒューマノイド:次世代手術訓練用人体モデルのデザイン

    新井史人, 益田泰輔, 太田信, 福田敏男, 木原信宏, 山下樹里, 鎮西清行, 芳賀洋一, 丸山央峰, 森建策, 斉藤延人, 相原一, 原田香奈子, 原田香奈子

    日本機械学会ロボティクス・メカトロニクス講演会講演論文集(CD-ROM) 2017 (0) 2A1-N07 2017年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmermd.2017.2A1-N07  

    ISSN:2424-3124

    詳細を見る 詳細を閉じる

    <p>Along with technological innovation of rapid prototyping, an artificial organ model with high shape and color reproducibility has become relatively easy to prepare and obtain. However there are few artificial organ models that reproduce physical properties such as hardness, softness, and surface friction characteristics. This study proposes to use "Bionic Humanoid" to quantitatively understand qualitative sensory expressions and quickly deliver technology seeds to society by eliminating trial and error. The Bionic Humanoid is an elaborate model of a human body equipped with sensors, to quantify such sensory expressions. The Bionic Humanoid can be used, for example, to quantify the requirements of medical doctors, assess surgical skills, replicate physical constraints for the development of a medical device, and provide young surgeons with training opportunities. We here describe a design concept and a prototype development of Bionic Humanoid.</p>

  48. 医療用能動カテーテルにおける先端技術:―摩擦を考慮した低侵襲医療―

    芳賀 洋一, 太田 信, 松永 忠雄

    トライボロジスト 62 (1) 30-36 2017年

    出版者・発行元:一般社団法人 日本トライボロジー学会

    DOI: 10.18914/tribologist.62.01_30  

    ISSN:0915-1168

  49. 皮膚組織を貫通する人工物の癒着強度評価試験のための基礎検討

    弓場 充, 坪子 侑佑, 白石 泰之, 井上 雄介, 平 恭紀, 太田 信, 山家 智之

    人工臓器 45 (2) S-159 2016年10月

    出版者・発行元:(一社)日本人工臓器学会

    ISSN:0300-0818

    eISSN:1883-6097

  50. 1D45 せん断応力を負荷した内皮細胞TGF-β1が共存培養モデル内平滑筋細胞の形質に与える影響

    HAN Xiaobo, 坂元 尚哉, 冨田 典子, Hui Meng, 佐藤 正明, 太田 信

    バイオエンジニアリング講演会講演論文集 2016 (28) "1D45-1"-"1D45-3" 2016年1月9日

    出版者・発行元:一般社団法人日本機械学会

    詳細を見る 詳細を閉じる

    Vascular smooth muscle cells (SMCs) are suggested to make functional changes under shear stress (SS) stimulation through intercellular communication with endothelial cells (ECs). In the present study, we constructed an EC-SMC co-culture model with phenotype-controlled SMCs, which is similar to normal healthy arterial walls, and then explored relationship between EC gene (TGF-β1) expression and SMC phenotype change under SS conditions. The result shows that the expression of contractile proteins in SMCs were at same level under 0.2, 2,6 or 10 Pa when TGF-β1 expression from EC was knocked down by SiRNA. In our previous experiment, we have reported that a low SS (0.2 Pa) or a high SS (10 Pa) could suppress the expression of contractile proteins in SMCs in a co-cultured model, therefore the present result suggests that TGF-β1 expression from EC could influence SMC response to SS.

  51. 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年

    ISSN:2186-5663

  52. AVEC CFD2016

    安西眸, TUPIN Simon, 渡邉和浩, RASHAD Sherif, 太田信

    日本バイオレオロジー学会誌(Web) 30 (2) 2016年

    ISSN:2186-5663

  53. 脳血管内治療デバイスと治療の有効性を予測する血管モデルの開発

    太田信, TUPIN Simon, 清水康智, 于凱鴻, 安西眸

    脳血管内治療(Web) 1 (Supplement) 2016年

    ISSN:2424-1709

  54. Effect of elasticity on wall shear stress inside cerebral aneurysm at anterior cerebral artery (vol 24, pg 349, 2016)

    Lijian Xu, Michiko Sugawara, Gaku Tanaka, Makoto Ohta, Hao Liu, Ryuhei Yamaguchi

    TECHNOLOGY AND HEALTH CARE 24 (4) 605-605 2016年

    出版者・発行元:IOS PRESS

    DOI: 10.3233/THC-161242  

    ISSN:0928-7329

    eISSN:1878-7401

  55. 血管内治療のための血管モデル開発

    太田信, 清水康智, TUPIN Simon, 大西泰平, 村元雄太, SEILLER Joanna, YU Kaihong, 安西眸

    日本機械学会年次大会講演論文集(CD-ROM) 2016 (0) W021003 2016年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmemecj.2016.W021003  

    ISSN:2424-2667

  56. 血管内治療デバイス留置シミュレータの開発(PVA-H血管バイオモデルを用いたカテーテルの変形挙動評価)

    大池亜斗夢, 高嶋一登, 葭仲潔, YU Kaihong, 太田信, 森浩二

    バイオエンジニアリング講演会講演論文集(CD-ROM) 28th (0) _2F25-1_-_2F25-5_ 2016年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebio.2016.28._2F25-1_  

    ISSN:2424-2829

    詳細を見る 詳細を閉じる

    We have developed a computer-based system to simulate a guidewire and a catheter in blood vessels for surgical planning, intra-operative assistance, and to facilitate the design of new guidewires and catheters. We have also developed an experimental apparatus which can be used not only for the validation of the numerical analyses but also as a simulation system. However, we have not evaluated the catheter motion in the experimental apparatus. Therefore in this study, first we added a mechanism to move the catheter to the experimental apparatus. Second, we evaluated the deformation behaviors of the guidewire and the catheter by the measurement of the 3D position and the contact force between the medical devices and the vessel. Finally, we compared the calculation results with the experimental results. The same tendency was seen in the trajectories and the contact force of both the experimental and calculated guidewire and catheter tips.

  57. ステントグラフトのエンドリークおよびマイグレーション評価用in-vitroモデルの開発

    大西泰平, LI Yujie, 乙幡周作, 出井正, 太田信

    バイオエンジニアリング講演会講演論文集(CD-ROM) 28th (0) _2F23-1_-_2F23-4_ 2016年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebio.2016.28._2F23-1_  

    ISSN:2424-2829

    詳細を見る 詳細を閉じる

    Stent grafting is one of the treatments for thoracic aortic aneurysm that is less invasive than open surgery. However, it sometimes involves in serious problems: Endoleak and Migration. These problems seem to have a relation to the oversize of stent or wrong position of stent on the arterial wall, and so the evaluation of the problems should be performed quantitatively using in-vitro model with observation of sealing. The purpose of this research is the development of in vitro model made of PVA-H (Poly Vinyl Alcohol Hydrogel) for evaluation of endoleak and migration on stent graft. We used Dip-Coating method to make the model. Dip-Coating is the method which forms a liquid film on the surface of the mold (Nylon12) by dipping the mold in PVA-H. As the result, the method using Nylon12 as a material of the mold enables to make the model with a similar surface roughness to the conventional method. In addition, the model has a high transparency and will be used for PIV.

  58. 2F22 動脈瘤ネックの流入領域に対するストラットの相対位置が瘤内流れに与える影響

    渡邉 和浩, 安西 眸, 太田 信

    バイオエンジニアリング講演会講演論文集 2016 (0) _2F22-1_-_2F22-4_ 2016年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebio.2016.28._2F22-1_  

    詳細を見る 詳細を閉じる

    For the treatment of cerebral aneurysms, flow diverter (FD) stent placement has been attracted. To evaluate a positioning error of stent on aneurysm flow, we analyze an influence of strut positions with relation to the inflow zone. Lattice Boltzmann flow simulation was applied to compute flow velocity in 3-D ideal aneurysm with a curved parent artery. Rectangular solid as a strut model was placed along to the neck plane. The results suggest that the flow velocity in the aneurysm is effectively reduced when the flow in the aneurysm and parent vessel flow are separated by a strut.

  59. 振動によるアブレーションカテーテルの冷却効果

    太田信, YU Kaihong, 山下哲以, 新行内成晃, 松本万夫

    バイオエンジニアリング講演会講演論文集(CD-ROM) 28th (0) B4 2016年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebio.2016.28.B4  

    ISSN:2424-2829

  60. 135 カテーテルアブレーション評価に用いる血液の粘度を考慮した作動流体の開発

    高橋 廉, 于 凱鴻, 太田 信

    東北支部総会・講演会 講演論文集 2016 (0) 67-68 2016年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmeth.2016.51.67  

  61. 脳動脈瘤の生化学的イベントと数値流体解析の応用に関するCutting‐Edge

    安西眸, ZHANG Mingzi, PUTRA Narendra Kurnia, 渡邉和浩, 太田信

    脳血管内治療(Web) 1 (Supplement) S47(J‐STAGE) 2016年

    ISSN:2424-1709

  62. 脳動脈瘤内の血液交換

    杉山慎一郎, 太田信, 冨永悌二

    日本機械学会バイオフロンティア講演会講演論文集 26th 23‐24 2015年10月1日

    ISSN:1348-2939

  63. PS5-4 CFD analyses for the flow in cancellous bone with LBM(PS5: Poster Short Presentation V,Poster Session)

    Sakuma Wataru, Nakayama Toshio, Anzai Hitomi, Nakamura Shuji, Sado Katsuyuki, Kutscher Konstantin, Stiebler Maik, Geier Martin, Krafczyk Manfred, Ohta Makoto

    Proceedings of the ... Asian Pacific Conference on Biomechanics : emerging science and technology in biomechanics 2015 (8) 302-302 2015年9月16日

    出版者・発行元:一般社団法人日本機械学会

  64. PS1-19 Lesion Size Comparison of Catheter Ablation between Open Irrigation and Vibration under No Flow Condition(PS1: Poster Short Presentation I,Poster Session)

    Yu Kaihong, Yamashita Tetsui, Shingyochi Shigeaki, Matsumoto Kazuo, Ohta Makoto

    Proceedings of the ... Asian Pacific Conference on Biomechanics : emerging science and technology in biomechanics 2015 (8) 240-240 2015年9月16日

    出版者・発行元:一般社団法人日本機械学会

  65. CFDで何をみるのか,見えるのか AVEC CFD2015

    安西眸, 下權谷祐児, 太田信, 八木高伸, 高尾洋之, 河野健一, 庄島正明

    日本バイオレオロジー学会年会プログラム・抄録集 38th 2015年

  66. A112 脳動脈瘤内の血液交換(A1-3 循環器のバイオメカニクス)

    杉山 慎一郎, 太田 信, 冨永 悌二

    バイオフロンティア講演会講演論文集 2015 (0) 23-24 2015年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebiofro.2015.26.23  

    ISSN:1348-2939

  67. S0220301 脳動脈瘤治療用ステントにおける自己組織化マップを用いた最適形状解析

    安西 眸, 吉田 裕貴, 下山 幸治, 大林 茂, 太田 信

    年次大会 2015 (0) _S0220301--_S0220301- 2015年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmemecj.2015._S0220301-  

    詳細を見る 詳細を閉じる

    As evaluation of hemodynamics in an aneurysm, a lot of parameters have been introduced. However, the relationship between stent geometry and each hemodynamic parameter is not clear enough. We applied Self-organizing Maps (SOM) to search the detailed relationship between stent strut and hemodynamic parameters. Two thousands of stent design candidates evaluated with five hemodynamic parameters and 25 stent geometry parameters were stored during the optimization process. By using SOM software, 2,000 design candidates were visualized into 30 2D-maps while preserving their own features in the original 30-dimensional design space. Each map was divided into 20 clusters to characterize stent design and flow reduction. By comparing each cluster, critical design for reduction effect of each hemodynamic parameter is suggested. Strut placement on the inflow area is important to reduce maximum shear rate. In addition to the inflow area, strut on the outflow area is required to reduce velocity, vorticity, and average shear rate.

  68. 1B44 血管内カテーテル/ガイドワイヤシミュレータの研究 : ガイドワイヤ形状の影響(OS8-4:循環器系のバイオメカニクスと医療機器(4))

    大池 亜斗夢, 高嶋 一登, 葭仲 潔, 于 凱鴻, 太田 信, 森 浩二

    バイオエンジニアリング講演会講演論文集 2015 (0) 91-92 2015年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebio.2015.27.91  

  69. 1B34 PIV,CFD,およびMRIにおける動脈瘤内流れ分布の比較(OS8-3:循環器系のバイオメカニクスと医療機器(3))

    李 玉潔, 米山 祐也, 磯田 治夫, 小杉 崇文, 小杉 隆司, 太田 信

    バイオエンジニアリング講演会講演論文集 2015 (0) 79-80 2015年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebio.2015.27.79  

  70. 脳動脈瘤治療用ステントにおける自己組織化マップを用いた最適形状解析

    安西眸, 吉田裕貴, 下山幸治, 大林茂, 太田信

    日本機械学会年次大会講演論文集(CD-ROM) 2015 ROMBUNNO.S0220301 2015年

    ISSN:2424-2667

  71. 実形状海綿骨内の数値流体力学解析

    佐久間 航, 中山 敏男, 安西 眸, 中村 修二, 佐渡 克行, 高川 浩和, 太田 信

    計算力学講演会講演論文集 2014 (27) 366-367 2014年11月22日

    出版者・発行元:一般社団法人日本機械学会

    ISSN:1348-026X

  72. 血行力学的解析を主眼とする脳動脈瘤データベースの構築

    杉山慎一郎, 太田信, 中山敏男, 清水宏明, 冨永悌二

    東北大学流体科学研究所共同利用・共同研究拠点流体科学研究拠点活動報告書 2013 157-158 2014年10月

  73. 脳動脈瘤治療用ステントにおける数値解析を用いた最適設計

    安西眸, CHOPARD Bastian, 中山敏男, ZHANG Mingzi, 吉田裕貴, 太田信

    計算工学講演会論文集(CD-ROM) 19 ROMBUNNO.D-3-2 2014年6月11日

    出版者・発行元:日本計算工学会

    ISSN:1342-145X

  74. 穿刺針周りの骨髄液流れの数値モデル化

    佐久間 航, 太田 信, 中山 敏男

    計算工学講演会論文集 Proceedings of the Conference on Computational Engineering and Science 19 3p 2014年6月

    出版者・発行元:日本計算工学会

  75. 2F46 血管内カテーテル/ガイドワイヤシミュレータの研究 : 血管モデル内でのワイヤの三次元追跡(GS6:血管内治療)

    都築 正太郎, 高嶋 一登, 葭仲 潔, 于 凱鴻, 太田 信, 森 浩二

    バイオエンジニアリング講演会講演論文集 2014 (0) 517-518 2014年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebio.2014.26.517  

  76. 2F43 アブレーションカテーテルの電極温度評価用システムの開発(GS6:血管内治療)

    于 凱鴻, 山下 哲以, 新行内 成晃, 太田 信

    バイオエンジニアリング講演会講演論文集 2014 (0) 511-512 2014年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebio.2014.26.511  

  77. 326 血管内ガイドワヤシミュレータの開発 : PVA-H血管バイオモデルを用いた実験と計算の結果比較

    都築 正太郎, 高嶋 一登, 葭仲 潔, 于 凱鴻, 太田 信, 森 浩二

    日本機械学会九州支部講演論文集 2014 (0) _326-1_-_326-2_ 2014年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmekyushu.2014.67._326-1_  

  78. せん断応力環境下においてNiTiワイヤの表面加工が内皮化に与える影響

    松本翔, HAN Xiaobo, 小林尚俊, 太田信

    日本機械学会年次大会講演論文集(CD-ROM) 2014 (0) _S0220202--_S0220202- 2014年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmemecj.2014._S0220202-  

    ISSN:2424-2667

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    Stent placement for stenosis has possibility of restenosis by intimal excessive proliferation with denudation of intima by stent placement. The goal of stent treatment is to cover the layer of endothelial cells (EC) on and around the stent. Intimal excessive proliferation is not occurred in the area with ECs. So, cell adhesive treatment for stent will suppress restenosis. To investigate the effect of surface treatment of Ni-Ti wire for stent under flow on endothelialization on implanted stent, we measured the density of ECs on and around the wire which was implanted on cultured ECs under shear stress (SS) environment. The treatment of collagen immobilization on Ni-Ti wire effects on the cell density on and around the wire. On collagen immobilized wire, ECs are attaching on lager area on wire than on wire without surface treatment. This mean that cell adhesive treatment by collagen immobilization promoted endothelialization.

  79. 実形状海綿骨内の数値流体力学解析

    佐久間航, 中山敏男, 安西眸, 中村修二, 佐渡克行, 高川浩和, 太田信

    日本機械学会計算力学講演会論文集(CD-ROM) 27th (0) 366-367 2014年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmecmd.2014.27.366  

    ISSN:2424-2799

  80. 1204 脳動脈瘤内の血液凝固促進を目指したステントデザインの最適化(バイオメカニクス)

    吉田 裕貴, 安西 眸, 太田 信

    最適化シンポジウム:OPTIS 2014 (0) _1204-1_-_1204-3_ 2014年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmeopt.2014.11.0__1204-1_  

    詳細を見る 詳細を閉じる

    Flow diverter stent (FD) is one of an efficient medical device or intracranial aneurysm. FD is a cylindrical device woven from metallic wires. It blocks the inflow entering an aneurysm to make blood coagulation in the aneurysm. But the device has a risk of blood coagulation as well in the parent artery attributable to chemical reactions between metal and blood. Therefore, we have developed the optimization program for mesh design of FD with simulated annealing and computational fluid dynamics to improve the treatment effect maintaining low wire density. In this report, we investigate the relationship between hemodynamic parameters and mesh design to determine the objective function for FD optimization.

  81. 脳動脈瘤内の血液凝固促進を目指したステントデザインの最適化

    吉田裕貴, 安西眸, 太田信

    日本機械学会最適化シンポジウム(CD-ROM) 11th (Web) 3p 2014年

    出版者・発行元:日本機械学会

  82. 医療機器開発と最適化手法の接点(トピックス)

    太田 信

    日本機械学会誌 117 (1150) 634-634 2014年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmemag.117.1150_634  

    ISSN:0021-4728

    eISSN:2424-2675

  83. 血行力学的解析を主眼とする脳動脈瘤データベースの構築

    杉山慎一郎, 太田信, 中山敏男, 清水宏明, 冨永悌二

    東北大学流体科学研究所共同利用・共同研究拠点流体科学研究拠点活動報告書 2012 109-110 2013年10月

  84. 血管内ガイドワイヤシミュレータの研究(実験結果に基づくシミュレーションモデルの改良)

    高嶋一登, 高嶋一登, 都築正太郎, 葭仲潔, 星野佑輔, 太田信, 森浩二

    日本機械学会年次大会講演論文集(CD-ROM) 2013 (0) _S022023-1-_S022023-3 2013年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmemecj.2013._S022023-1  

    ISSN:2424-2667

    詳細を見る 詳細を閉じる

    We have developed a system to simulate a guidewire in blood vessels for surgical planning,intra-operative assistance and the design of new guidewires.In this study,we compared the simulation results with the experimental results for validation of the simulation system and evaluated the parameters of guidewire model.The model of the guidewire is constructed with viscoelastic springs and segments.The proximal part of the guidewire model is constrained by the catheter model,which is fixed and assumed to be a rigid tube.The motion of the guidewire in torus-shaped blood vessel model was calculated when the proximal part of the guidewire model was pushed and twisted.Collisions between the guidewire and the vessel are calculated and the contact forces are determined according to the stiffness of the vessel wall.The same tendency was seen in the trajectory of the both guidewire tips.The viscous term,the friction,the number of the segments affected the motion of the guidewire tip.

  85. S021015 せん断応力を負荷した共存培養モデル内の血管平滑筋細胞からのMMPの産生量の変化([S021]多細胞・組織への展開を目指した細胞工学)

    Han Xiaobo, 坂元 尚哉, 冨田 典子, Hui Meng, 佐藤 正明, 太田 信

    年次大会 2013 (0) _S021015-1-_S021015-4 2013年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmemecj.2013._S021015-1  

    詳細を見る 詳細を閉じる

    Vascular smooth muscle cells(SMCs) are suggested to make functional changes under shear stress(SS) stimulation through intercellular communication with endothelial cells(ECs).In the present study,we constructed an EC-SMC coculture model with phenotype-controlled SMCs,which is similar to normal healthy arterial walls,and then explored relationship between SS and matrix metalloproteinases-2(MMP-2) production from SMC in the model.The result shows that application of a physical level SS of 2 Pa to endothelial cells in the model suppressed the expression of activated MMP-2 by SMCs compared to the statically cultured model,while MMP-2 production by SMCs did not decrease under a low SS of 0.2 Pa or a high SS of 10 Pa.Since MMP-2 could degrade extracellular matrix(ECM),activity of MMP-2 under low or high SS might be related to pathological remodeling of blood vessels.These results could help better understanding of relationship between the local hemodynamics and the development of vascular diseases.

  86. 3C08 実形状動脈瘤を用いたステント形状最適化プログラム開発に関する研究(GS7-4:循環器系のバイオメカニクス(4))

    安西 眸, FALCONE Jean-Luc, CHOPARD Bastien, 太田 信

    バイオエンジニアリング講演会講演論文集 2013 (0) 535-536 2013年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebio.2013.25.535  

  87. 3C07 親血管形状による動脈瘤の分類に対するステントストラットパターンの最適化に関する研究(GS7-4:循環器系のバイオメカニクス(4))

    中山 敏男, 鄭 信圭, SRINIVAS Karkenahalli, 太田 信

    バイオエンジニアリング講演会講演論文集 2013 (0) 533-534 2013年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebio.2013.25.533  

  88. 2C16 血管内圧による狭窄部の形状変化と血流分布の関連性(GS7-2:循環器系のバイオメカニクス(2))

    清水 康智, 劉 磊, 信太 宗也, 船本 健一, 早瀬 敏幸, 太田 信

    バイオエンジニアリング講演会講演論文集 2013 (0) 343-344 2013年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebio.2013.25.343  

  89. 2C14 せん断応力を負荷した共存培養モデル内の血管平滑筋細胞の形質変化(GS7-1:循環器系のバイオメカニクス(1))

    Han Xiaobo, 坂元 尚哉, 富田 典子, Hui Meng, 佐藤 正明, 太田 信

    バイオエンジニアリング講演会講演論文集 2013 (0) 339-340 2013年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebio.2013.25.339  

  90. 1F11 血管内ガイドワイヤシミュレータの研究 : 計算と実験の結果比較(GS18-1:医療機器(診断・治療)(1))

    都築 正太郎, 葭仲 潔, 星野 佑輔, 太田 信, 森 浩二, 高嶋 一登

    バイオエンジニアリング講演会講演論文集 2013 (0) 199-200 2013年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebio.2013.25.199  

  91. 頚動脈内膜剥離術あるいは頚動脈ステント留置術施行後の患者固有データに基づく頚動脈血流の流体力学的シミュレーション

    早瀬仁志, 徳永浩司, 中山敏男, 杉生憲志, 西田あゆみ, 有光帥二, 菱川朋人, 小野成紀, 太田信, 伊達勲

    岡山医学会雑誌 125 (1) 5-7 2013年

    出版者・発行元:岡山医学会

    DOI: 10.4044/joma.125.5  

    ISSN:0030-1558

  92. 血流低減を目的とした脳動脈瘤用ステントデザインの最適設計

    太田 信, 安西 眸, 中山 敏男

    理論応用力学講演会 講演論文集 62 (0) 200-200 2013年

    出版者・発行元:日本学術会議 「機械工学委員会・土木工学・建築学委員会合同IUTAM分科会」

    DOI: 10.11345/japannctam.62.0.200.0  

    詳細を見る 詳細を閉じる

    血管壁が瘤状に肥大化する病気である脳動脈瘤の治療法に血管内治療がある.近年ではステントと呼ばれる,動脈瘤内の血流を低減させ血栓化を促す医療デバイスが注目を集めている.現状のステントは親血管が血栓で塞栓する可能性が指摘されている.これに対して,近年では最適化と呼ばれる手法を用いて,高多孔率でありながら血流低減効果の高いステント形状の探索が行われている.しかしながらこれまでの研究において,最適化は多数の計算モデルを必要とすることから,微細なステント形状に適合した計算格子を作成するために作業者に大きな負担がかかることが指摘されていた.そこで著者らは理想形状動脈瘤に対し,格子ボルツマン法と擬似焼きなまし法を組み合わせることにより,ステント形状作成,計算格子生成,数値流体計算,血流低減効果の評価の一連の過程を自動化した,ステント形状最適化プログラムの開発を行い,自動化プロセスの有効性を示した.

  93. 脳動脈瘤における動脈硬化性変化と血行動態との関係

    杉山慎一郎, 中山敏男, 太田信, 清水宏明, 藤原悟, 冨永悌二

    日本神経放射線学会プログラム・抄録集 42nd 144 2013年

  94. 血行力学的解析を主眼とする脳動脈瘤データベースの構築

    杉山慎一郎, 太田信, 中山敏男, 清水宏明, 冨永悌二

    東北大学流体科学研究所共同利用・共同研究拠点流体科学研究拠点活動報告書 2011 85-86 2012年10月

  95. 脳動脈瘤用フローダイバータステントモデル化に対する圧力勾配と瘤内流れに関する研究

    三浦幸久, 安西眸, 中山敏男, 太田信

    日本機械学会東北支部総会・講演会講演論文集 47th 20‐21 2012年3月13日

  96. Micro‐CTによる脳動脈瘤コイルモデルの可視化に関する研究

    久世政範, 太田信

    日本機械学会東北支部総会・講演会講演論文集 47th 34‐35 2012年3月13日

  97. 脳動脈瘤の形状による分類とステントの最適化

    中山敏男, JEONG Shinkyu, SRINIVAS Karkenahalli, 太田信

    バイオエンジニアリング講演会講演論文集 24th (CD-ROM) ROMBUNNO.7F26 2012年1月6日

    ISSN:1348-2920

  98. 格子ボルツマン法を用いた脳動脈瘤治療用ステントの形状最適化プログラムの開発

    安西眸, FALCONE Jean‐Luc, CHOPARD Bastien, 太田信

    バイオエンジニアリング講演会講演論文集 24th (CD-ROM) ROMBUNNO.7F24-_7F24-2_ 2012年1月6日

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebio.2012.24._7f24-1_  

    ISSN:1348-2920

    eISSN:2424-2829

  99. 血管壁の動きを考慮したPVA脳動脈瘤バイオモデル内拍動流れのPIV計測

    信太宗也, 太田信

    バイオエンジニアリング講演会講演論文集 24th (CD-ROM) ROMBUNNO.8F35 2012年1月6日

    ISSN:1348-2920

  100. 医療デバイス周りの血流流体力学的見地からの血栓形成

    太田信, WETZEL S., 安西眸, 中山敏男, HAN Xiaobo, 清水康智, 小澤桂, 冨田典子

    日本バイオマテリアル学会シンポジウム予稿集 2012 2012年

  101. S021022 脳動脈瘤に対するステントストラット位置の自動最適化に関する研究

    安西 眸, FALCONE Jean-Luc, CHOPARD Bastien, 太田 信

    年次大会 2012 (0) _S021022-1-_S021022-3 2012年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmemecj.2012._S021022-1  

    詳細を見る 詳細を閉じる

    To produce an optimal design of stents for cerebral aneurysm is attracted for reducing the flow in the aneurysm efficiently. This report demonstrates the optimization for 3-D aneurysm with two different objectives. As the result, the optimum stent for the maximum velocity has denser struts on distal of the neck. On the other hand, the optimum stent for average velocity has denser struts on proximal of the neck.

  102. ステントストラットパターンの最適化を用いたステント開発に関する研究

    中山敏男, JEONG Shinkyu, SRINIVAS Karkenahalli, 太田信

    日本機械学会年次大会講演論文集(CD-ROM) 2012 (0) _S021021-1-_S021021-5 2012年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmemecj.2012._S021021-1  

    ISSN:2424-2667

    詳細を見る 詳細を閉じる

    Stent implantation in intracranial arteries is termed as endovascular treatment. The number of such cases has been increasing worldwide because the surgical damage resulting from stenting seem to be less than that of other treatments. A side wall type idealized aneurysm shape reconstructed by straight pipe and half sphere were used, Z-type stent was used. CFD analysis was performed each aspect ratio aneurysm and stent strut pattern. The optimization by the process of Multi-Objective Genetic Algorithm and Kriging was performed to the CFD results From the results, we report the development of new stent strut pattern in cerebral aneurysm using the computational fluid dynamics (CFD) and optimization.

  103. 114 Micro-CTによる脳動脈瘤コイルモデルの可視化に関する研究(バイオエンジニアリングII,一般講演)

    久世 政範, 太田 信

    東北支部総会・講演会 講演論文集 2012 (0) 34-35 2012年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmeth.2012.47.34  

  104. 107 脳動脈瘤用フローダイバータステントモデル化に対する圧力勾配と瘤内流れに関する研究(バイオエンジニアリングI,一般講演)

    三浦 幸久, 安西 眸, 中山 敏男, 太田 信

    東北支部総会・講演会 講演論文集 2012 (0) 20-21 2012年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmeth.2012.47.20  

  105. A104 PVA-H血管バイオモデルの冷却時間と厚さ制御に関する研究(A1-1 生体流体工学1)

    大竹 匡, 太田 信

    バイオフロンティア講演会講演論文集 2012 (0) 7-8 2012年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebiofro.2012.23.7  

    ISSN:1348-2939

  106. 8F36 血管バイオモデル狭窄部のプラーク硬さが定常流に与える影響(GS02 循環系のバイオメカニクス(モデリング,シミュレーション)1)

    清水 康智, 信太 宗也, 早瀬 敏幸, 太田 信

    バイオエンジニアリング講演会講演論文集 2012 (0) _8F36-1_-_8F36-2_ 2012年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebio.2012.24._8F36-1_  

  107. 8F35 血管壁の動きを考慮したPVA脳動脈瘤バイオモデル内拍動流れのPIV計測(GS02 循環系のバイオメカニクス(モデリング,シミュレーション)1)

    信太 宗也, 太田 信

    バイオエンジニアリング講演会講演論文集 2012 (0) _8F35-1_-_8F35-2_ 2012年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebio.2012.24._8F35-1_  

  108. 8E23 PVA-H血管バイオモデルの厚さ制御機構の開発(OS24 人工臓器の実用化について2)

    清光 千早, 小助川 博之, 黒木 完樹, 高嶋 一登, 太田 信

    バイオエンジニアリング講演会講演論文集 2012 (0) _8E23-1_-_8E23-2_ 2012年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebio.2012.24._8E23-1_  

  109. 7F26 脳動脈瘤の形状による分類とステントの最適化(GS01 循環系のバイオメカニクス(脳動脈瘤,ステント)

    中山 敏男, 鄭 信圭, SRINIVAS Karkenahalli, 太田 信

    バイオエンジニアリング講演会講演論文集 2012 (0) _7F26-1_-_7F26-2_ 2012年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebio.2012.24._7F26-1_  

  110. 7F24 格子ボルツマン法を用いた脳動脈瘤治療用ステントの形状最適化プログラムの開発(GS01 循環系のバイオメカニクス(脳動脈瘤,ステント)

    安西 眸, FALCONE Jean-Luc, CHOPARD Bastien, 太田 信

    バイオエンジニアリング講演会講演論文集 2012 (0) _7F24-1_-_7F24-2_ 2012年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebio.2012.24._7F24-1_  

  111. 脳動脈瘤に対するステントストラット位置の自動最適化に関する研究

    安西眸, FALCONE Jean-Luc, CHOPARD Bastien, 太田信

    日本機械学会年次大会講演論文集(CD-ROM) 2012 ROMBUNNO.S021022 2012年

    ISSN:2424-2667

  112. 未破裂脳動脈瘤の破裂リスクに関する3次元可視化システムを用いたCFD解析の試み

    入江 恵子, 太田 信, 安西 眸, 根來 真, 廣瀬 雄一

    CI研究 : progress in computed imaging 33 (2) 119-125 2011年9月30日

    ISSN:0918-7073

  113. 未破裂脳動脈瘤の破裂リスクに関する3次元可視化システムを用いたCFD解析の試み

    入江恵子, 太田信, 安西眸, 中山敏男, 根來真, 廣瀬雄一

    日本バイオレオロジー学会年会プログラム・抄録集 34th 53 2011年6月3日

  114. 次世代の画像解析ソフトウェア サブトラクションソフトによる脳動脈瘤の評価―ソフトウェアの開発評価とその展望

    茅野伸吾, 黒田英隆, 梁川功, 高橋明, 太田信

    Innervision 26 (3) 18-21 2011年2月25日

    ISSN:0913-8919

  115. NBCA-Lipiodol混合液による動脈塞栓効果の基礎的検討

    高澤 千晶, 清治 和将, 松永 賢一, 高瀬 圭, 高橋 昭喜, 松橋 俊夫, 信太 宗也, 太田 信

    日本医学放射線学会学術集会抄録集 70回 S316-S316 2011年2月

    出版者・発行元:(公社)日本医学放射線学会

    ISSN:0048-0428

  116. 血流数値解析の3次元可視化による効果的な脳動脈瘤ステント配置の予測

    安西眸, 中山敏男, 入江恵子, 太田信

    バイオエンジニアリング講演会講演論文集 23rd 253-254 2011年1月7日

    ISSN:1348-2920

  117. 最適化設計法による脳動脈瘤用ステントのストラットパターンの開発

    中山敏男, JEONG Shinkyu, SRINIVAS Karkenahalli, 太田信

    バイオエンジニアリング講演会講演論文集 23rd 251-252 2011年1月7日

    ISSN:1348-2920

  118. A210 PVAバイオモデルを用いたアブレーションカテーテルの温度分布の評価に関する研究(A2-2 生体計測・医療機器)

    高橋 亮太郎, 山下 哲以, 太田 信

    バイオフロンティア講演会講演論文集 2011 (0) 97-98 2011年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebiofro.2011.22.97  

    ISSN:1348-2939

  119. 8B-03 模擬血管ソフトマターとステント合金の摩擦特性(OS-13(1) 循環器系の医療マイクロデバイス)

    小助川 博之, FRIDRICI Vincent, KAPSA Philippe, STOIMENOV Boyko, 太田 信

    バイオエンジニアリング講演会講演論文集 2010 (0) 17-18 2011年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebio.2010.23.17  

  120. 8F-14 最適化設計法による脳動脈瘤用ステントのストラットパターンの開発(OS-1(2) 循環器系のバイオメカニクスと医療機器設計(3))

    中山 敏男, 鄭 信圭, SRINIVAS Karkenahalli, 太田 信

    バイオエンジニアリング講演会講演論文集 2010 (0) 251-252 2011年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebio.2010.23.251  

  121. 8F-15 血流数値解析の3次元可視化による効果的な脳動脈瘤ステント配置の予測(OS-1(2) 循環器系のバイオメカニクスと医療機器設計(3))

    安西 眸, 中山 敏男, 入江 恵子, 太田 信

    バイオエンジニアリング講演会講演論文集 2010 (0) 253-254 2011年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebio.2010.23.253  

  122. 脳動脈瘤内の血流を低下させるためのステントストラットの探索結果

    中山敏男, JEONG Shinkyu, KARKENAHALLI Srinivas, 太田信

    バイオエンジニアリング講演会講演論文集 22nd 334 2010年1月8日

    ISSN:1348-2920

  123. 血管バイオモデルを用いたPIVによる瘤内コイル周りの血流解析

    太田信, 野田茂穂, 深作和明, 姫野龍太郎, 松本薫

    日本バイオレオロジー学会年会プログラム・抄録集 33rd 2010年

  124. ブドウ球菌の2成分性毒素γヘモリジンが形成するヘテロヘプタマー膜孔複合体の立体構築とサブユニット間配置の定量的解析

    冨田典子, 安西眸, 阿部和代, 金子淳, 神尾好是, 太田信

    日本農芸化学会大会講演要旨集 2010 2010年

  125. 0211 ポリビニルアルコールハイドロゲルを用いた血管バイオモデリング壁の力学解析(OS2:心臓血管壁のバイオエンジニアリング)

    小助川 博之, 信太 宗也, 橋田 葉子, 太田 信

    バイオエンジニアリング講演会講演論文集 2009 (0) 20-20 2010年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebio.2009.22.20  

  126. 0839 脳動脈瘤内の血流を低下させるためのステントストラットの探索結果(GS9:ステント)

    中山 敏男, 鄭 信佳, KARKENAHALLI Srinivas, 太田 信

    バイオエンジニアリング講演会講演論文集 2009 (0) 334-334 2010年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebio.2009.22.334  

  127. 血管バイオモデル内流れのPIV計測のための疑似血液流体開発(生体の流れ(1),一般講演)

    信太 宗也, 小助川 博之, 橋田 葉子, 太田 信

    日本流体力学会年会講演論文集 2010 217-217 2010年

    出版者・発行元:日本流体力学会

    詳細を見る 詳細を閉じる

    An in-vitro work fluid to apply to Poly (vinyl alcohol) hydrogel (PVA) model integrated in a circulation system are developed using glycerol. The index of refraction of the fluid is matched to that of PVA model and the model is connected to the circulation system with a pulsatile pump. The viscosity can also be changeable for matching the blood. Since the compliance of PVA model is similar to the arterial wall, the circulation system with PVA model will be helpful for comparison of flow dynamics in rigid wall or for evaluation of medical devices such as stent or coil touching on the artery. These topics are also strong relationship with the rupture of cerebral aneurysm that usually causes subarachnoidal hemorrhage (SAH) and sever morbidity.

  128. 197 PVAバイオモデルの壁厚測定(バイオエンジニアリングII,一般講演)

    清光 千早, 小助川 博之, 橋田 葉子, 太田 信

    東北支部総会・講演会 講演論文集 2010 (0) 194-195 2010年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmeth.2010.45.194  

  129. 脳動脈瘤コイル塞栓後の血流変化の計算機流体力学による評価

    深作和明, 根来真, 野田茂穂, 松本薫, 太田信, 奈良一成, 高木周, 姫野龍太郎

    J Neuroendovascular Ther 3 (4) 263 2009年11月1日

    ISSN:1882-4072

  130. コイルを留置させた脳動脈瘤モデルでの血流の定量的測定法の開発

    松本薫, 野田茂穂, 深作和明, 姫野龍太郎, 太田信

    J Neuroendovascular Ther 3 (4) 257 2009年11月1日

    ISSN:1882-4072

  131. 3次元可視化システムを用いた脳動脈瘤ステント周りの血流数値解析の可視化

    安西眸, 竹島由里子, 中山敏男, 太田信

    日本機械学会年次大会講演論文集 2009 (Vol.6) 177-178 2009年9月12日

  132. コイルが留置された脳動脈瘤モデル内の流れに関する研究

    松本薫, 野田茂穂, 深作和明, 姫野龍太郎, 太田信

    日本機械学会年次大会講演論文集 2009 (Vol.6) 171-172 2009年9月12日

  133. ステントストラット配置が脳動脈瘤モデル内の流れに与える影響

    奥野健二郎, 中山敏男, RUEFENACHT Daniel A, 太田信

    バイオエンジニアリング講演会講演論文集 21st 61-62 2009年1月22日

    ISSN:1348-2920

  134. 脳動脈瘤内の血流減少における最適な箇所の探索

    中山敏男, JEONG Shinkyu, KARKENAHALLI Srinivas, RUEFENACHT Daniel A, 高橋明, 太田信

    バイオエンジニアリング講演会講演論文集 21st 63-64 2009年1月22日

    ISSN:1348-2920

  135. ブドウ球菌の2成分性毒素γヘモリジンが形成するヘテロヘプタマー膜孔複合体の立体構造解析

    冨田典子, 安西眸, 金子淳, 神尾好是, 太田信

    日本ブドウ球菌研究会プログラム・講演要旨集 54th 2009年

  136. J0203-1-2 コイルが留置された脳動脈瘤モデル内の流れに関する研究(医療診断のためのマルチスケール血流動態計測と解析(1))

    松本 薫, 野田 茂穂, 深作 和明, 姫野 龍太郎, 太田 信

    年次大会講演論文集 2009 (0) 171-172 2009年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmemecjo.2009.6.0_171  

    詳細を見る 詳細を閉じる

    The coil embolization for cerebral aneurysm is one of the effective treatments. However, sometimes blood flow may induce recanalization or growth of the aneurysm. Therefore, the measurements of flow speed with coils in aneurysm are necessary for analyzing the effect of coil on the flow in the aneurysm. However, the method for quantitative measurement using an optical image based velocimetry such as PIV has not been established because coil makes shades in flow field. In this study, we tried to identify the shades by coils and the traces by particles by superimposing consecutive images. Several parts of coils are placed on out of aneurysm cavity and it placement may induce that the speed in inflow zone with coils is larger than that of no coil model. These results will clarify the relationship between coil formation at the neck and the flow in aneurysm.

  137. 206 ステントストラット配置が脳動脈瘤モデル内の流れに与える影響(OS1-2:循環器系のバイオメカニクス(2),OS1:循環器系のバイオメカニクス)

    奥野 健二郎, 中山 敏男, RUFENACHT Daniel A., 太田 信

    バイオエンジニアリング講演会講演論文集 2008 (0) 61-62 2009年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebio.2008.21.61  

  138. 207 脳動脈瘤内の血流減少における最適な箇所の探索(OS1-2:循環器系のバイオメカニクス(2),OS1:循環器系のバイオメカニクス)

    中山 敏男, 鄭 信圭, KARKENAHALLI Srinivas, RUFENACHT Daniel A., 高橋 明, 太田 信

    バイオエンジニアリング講演会講演論文集 2008 (0) 63-64 2009年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebio.2008.21.63  

  139. 327 血管バイオモデリング開発を目的としたポリビニルアルコールハイドロゲルの力学的特性評価(OS6-4:生体モデリングとシミュレーション(4),OS6:生体モデリングとシミュレーション)

    小助川 博之, 間々田 圭祐, 劉 磊, 黒木 完樹, 井上 浩介, 早瀬 敏幸, 太田 信

    バイオエンジニアリング講演会講演論文集 2008 (0) 355-356 2009年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebio.2008.21.355  

  140. 428 Poly (Vinyl Alcohol) Hydrogelを用いた口腔粘膜モデルの開発(OS2-2:軟組織のバイオメカニクス(2),OS2:軟組織のバイオメカニクス)

    間々田 圭祐, 小助川 博之, FRIDRICI Vincent, 及川 直人, 片倉 裕司, 柴田 幸彦, 黒木 完樹, 太田 信

    バイオエンジニアリング講演会講演論文集 2008 (0) 389-390 2009年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebio.2008.21.389  

  141. J0203-1-5 3次元可視化システムを用いた脳動脈瘤ステント周りの血流数値解析の可視化(医療診断のためのマルチスケール血流動態計測と解析(1))

    安西 眸, 竹島 由里子, 中山 敏男, 太田 信

    年次大会講演論文集 2009 (0) 177-178 2009年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmemecjo.2009.6.0_177  

    詳細を見る 詳細を閉じる

    The effect of stent on the flow reduction in cerebral aneurysm has been reported in CFD studies showing the stent position or the strut shape may affect the flow reduction. The 3D visualization may help easily to specify the inlet zone from parent artery to aneurysm and to find the relationship between the effective strut position and the flow pattern. Then we simulated adding a strut to a stent model on the inlet zone after specifying the zone using 3D visualization system. After moving the strut and repeating the visualization of results, we found a strut on the zone may reduce the flow into aneurysm effectively. The results may suggest the 3D visualization is useful for the assessment of strut position with effective reduction of flow into aneurysm.

  142. 803 頸動脈狭窄に対してステント留置を施行した術前・術後の血流解析(OS24.一般セッション(1) 心臓-循環器系生体解析,オーガナイズドセッション)

    森 太志, 茅野 伸吾, 高橋 明, 太田 信, 松澤 照男

    計算力学講演会講演論文集 2008 (21) 325-326 2008年11月1日

    出版者・発行元:一般社団法人日本機械学会

    ISSN:1348-026X

  143. 脳動脈瘤用ステントの血流減少効果を解析するために

    太田信

    日本機械学会誌 111 (1075) 538-538 2008年6月

  144. 脳血管内カテーテル/ガイドワイヤシミュレータの開発

    高嶋 一登, 大田 慎三, 太田 信, 葭仲 潔, 向井 利春

    日本バイオレオロジー学会誌(B&R) = Journal of Japanese Society of Biorheology 22 (1) 12-18 2008年3月25日

    出版者・発行元:日本バイオレオロジ-学会

    DOI: 10.11262/jpnbr1987.22.1_12  

    ISSN:0913-4778

    詳細を見る 詳細を閉じる

    We have developed a catheter and guidewire simulator for interventional therapy. This system was developed to predict the course of approach to a lesion and to present numerical results and animation for surgical planning, intra-operative assistance, the analysis of the structure of the guidewire and the design of a new guidewire. The model of the guidewire is constructed with viscoelastic springs and segments as the dynamic deformation of a flexible structure. The proximal part of the guidewire is inserted into the catheter model. The vessel is an elastic circular cylinder, whose shape is defined by the centerline and the radii. Collisions between the guidewire and the vessel are calculated and the contact forces are determined according to the stiffness and friction of the vessel wall. In this article, we introduce our simulator and several examples of the simulation results.

  145. 企業とのwin-win共同研究によるPVAハイドロゲル外科手術練習用口腔粘膜模型の開発

    太田信

    歯科技工 36 (3) 316-318 2008年3月

  146. 歯科技工技術と新材料の融合により生体の触感・質感・形状に近づく外科手術練習用口腔模型(口腔粘膜&骨模型)の開発―医療分野における歯科技工技術応用の可能性拡大の模索から

    及川直人, 片倉裕司, 柴田幸彦, 太田信

    歯科技工 36 (3) 305-315 2008年3月

  147. 脳動脈瘤ネットにおけるステントストラットパターンと瘤内の血行動態に関する研究

    中山敏男, 太田信, RUEFENACHT Daniel A, 高橋明

    バイオエンジニアリング講演会講演論文集 20th 33-34 2008年1月24日

    ISSN:1348-2920

  148. 頸部内頸動脈狭窄症におけるCEAとCAS術後の医用画像を用いた患者特異的モデルと仮想モデルの流体力学シミュレーション

    早瀬仁志, 中山敏男, 徳永浩司, 杉生憲志, 西田あゆみ, 有光帥二, 菱川朋人, 小野成紀, 太田信, 伊達勲

    日本脳神経外科学会総会抄録集(CD-ROM) 67th 2008年

    ISSN:1347-9040

  149. 脳動脈瘤用ステントの血流減少効果を解析するために(トピックス)

    太田 信

    日本機械学会誌 111 (1075) 538-538 2008年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmemag.111.1075_538  

    ISSN:0021-4728

    eISSN:2424-2675

  150. 117 脳動脈瘤ネックにおけるステントストラットパターンと瘤内の血行動態に関する研究(OS2-5:生体モデリングとシミュレーション(5),OS2:生体モデリングとシミュレーション)

    中山 敏男, 太田 信, RUFENACHT Daniel A., 高橋 明

    バイオエンジニアリング講演会講演論文集 2007 (0) 33-34 2008年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebio.2007.20.33  

  151. 701 各ステントストラットが瘤内の血行動態へおよぼす影響(J06-1 医療診断のためのマルチスケール血流動態計測と解析(1),ジョイントセッション,21世紀地球環境革命の機械工学:人・マイクロナノ・エネルギー・環境)

    中山 敏男, 太田 信, RUFENACHT Daniel A., 高橋 明

    年次大会講演論文集 2008 (0) 17-18 2008年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmemecjo.2008.6.0_17  

    詳細を見る 詳細を閉じる

    In this research, we report the effect of each stent strut in aneurysm neck on hemodynamics using the computational fluid dynamics (CFD). The stent strut that deleted a part of it was constructed and that stent was stenting in aneurysm neck, CFD was performed using its shape. By comparing the results of removal stent strut case, the normal stenting case, and the no stenting case, the effect on hemodynamics by each stent strut was researched. From the results, we showed the wall shear stress distribution's greatly changing.

  152. B408 PVAハイドロゲルとメッシュ材料を用いた異方性血管モデルの製作(生体材料)

    劉 磊, 小助川 博之, 太田 信, 早瀬 敏幸

    バイオフロンティア講演会講演論文集 2008 (0) 145-146 2008年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebiofro.2008.19.145  

    ISSN:1348-2939

  153. 128 Poly (vinyl alcohol) gelを用いた口腔粘膜モデルの開発と一対比較法による物性評価(バイオエンジニアリング)

    間々田 圭祐, 小助川 博之, 山口 晃史, 及川 直人, 片倉 裕司, 柴田 幸彦, 黒木 完樹, 太田 信

    東北支部総会・講演会 講演論文集 2008 (0) 57-58 2008年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmeth.2008.43.57  

  154. 頸動脈狭窄症におけるステント術前・術後の血流解析(生体(3),一般講演)

    森 太志, 茅野 伸吾, 高橋 明, 太田 信, 松澤 照男

    日本流体力学会年会講演論文集 2008 408-408 2008年

    出版者・発行元:日本流体力学会

    詳細を見る 詳細を閉じる

    The carotid artery is a part to which arteriosclerosis is done easily most in the artery of the whole body. There is stent treatment as a treatment method of this disease. The stent treatment is a less-invasive therapy for Carotid Artery Stenosis (CAS). There are various stent research, however, dynamics factor i.e., the influence of the change in the blood flow and Wall Shear Stress (WSS) which may express the possibility of thrombus growth after stent treatment have not been clarified. In this research, we pay attentions to stent expand aspect because the different of stent expand aspect concerned with a new disease. And reconstructed a before-and-after carotid artery and analyzed it.

  155. 頸動脈狭窄に対してステント留置を施行した術前・術後の血流解析

    森太志, 茅野伸吾, 高橋明, 太田信, 松澤照男

    日本機械学会計算力学講演会論文集(CD-ROM) 21st (0) 325-326 2008年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmecmd.2008.21.325  

    ISSN:2424-2799

  156. 外科手術練習用口腔粘膜及び骨模型の開発

    及川 直人, 柴田 幸彦, 片倉 裕司, 山口 晃史, 熱海 啓一, 熊谷 康宏, 太田 信

    日本歯科技工学会雑誌 28 (2) 268-268 2007年12月20日

    ISSN:0914-7713

  157. ステントによる脳動脈瘤内血流の減少シミュレーション

    太田信, 小助川博之, 間々田圭祐, 奥野健二郎, 黒木完樹, 中山敏男

    日本バイオマテリアル学会大会予稿集 29th 55 2007年11月26日

  158. ネックにおけるステントデザインがおよぼす脳動脈瘤内の血行動態への影響

    中山敏男, 太田信, 奥野健二郎, 高橋明, ダニエルルフナハト

    J Neuroendovascular Ther 1 (2) 140 2007年11月1日

    ISSN:1882-4072

  159. 外科手術練習用口腔粘膜及び骨模型の開発

    及川 直人, 柴田 幸彦, 片倉 裕司, 山口 晃史, 熱海 啓一, 熊谷 康宏, 太田 信

    日本歯科技工学会学術大会 : プログラム : 講演内容抄録 29 51-51 2007年9月22日

  160. 力学特性を付与した脳動脈瘤モデル開発のためのPoly(vinyl alcohol)hydro‐gelの物性評価

    小助川博之, 間々田圭祐, 劉磊, 黒木完樹, 早瀬敏幸, 太田信

    日本バイオレオロジー学会年会プログラム・抄録集 30th 69 2007年6月6日

  161. 実形状ステントを設置した脳動脈瘤内の血流シミュレーション

    中山敏男, 太田信, RUEFENACHT Daniel A, 高橋明

    バイオエンジニアリング講演会講演論文集 19th 84-85 2007年1月6日

    ISSN:1348-2920

  162. 頸部内頸動脈狭窄症におけるCEAとCASの術前後の3D-CTA,3D-DSA画像を使った生体力学シミュレーション

    早瀬仁志, 徳永浩司, 中山敏男, 西田あゆみ, 杉生憲志, 小野成紀, 小野田惠介, 太田信, 伊達勲

    日本脳神経外科学会総会抄録集(CD-ROM) 66th 2007年

    ISSN:1347-9040

  163. カテーテルシミュレータの開発(第2報,ガイドワイヤのトルク伝達性の評価):第2報, ガイドワイヤのトルク伝達性の評価

    高嶋 一登, 大田 慎三, 太田 信, 葭仲 潔, 向井 利春

    日本機械学会論文集 C編 73 (735) 2988-2995 2007年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/kikaic.73.2988  

    ISSN:0387-5024

    詳細を見る 詳細を閉じる

    We have developed catheter simulation system in blood vessels for surgical planning and intraoperative assistance. In this study, we evaluated the torquability of the guidewire model for the simulation system. The model of the guidewire is constructed with viscoelastic springs and segments as the dynamic deformation of a flexible structure. The vessel is an elastic circular cylinder, whose shape is defined by the centerline and the radii. Collisions between the guidewire and the vessel are calculated and the contact forces are determined according to the stiffness and friction of the vessel wall. Using these models, the trajectory of the guidewire tip was calculated when the proximal part of the guidewire model was twisted at a constant speed. When the friction coefficient between the guidewire and the vessel is large, the guidewire tip vibrates. When the guidewire is twisted, there is a lag before the guidewire tip starts rotating and friction obstructs this rotation. Besides the friction coefficient, the shape of the blood vessel also affects the motion of the guidewire tip. When the guidewire becomes stiffer, the torquability of guidewire tip increases. This simulator would be useful for the analysis of the structure of the guidewire and may help guide the design of new guidewire.

  164. 317 実形状ステントを設置した脳動脈瘤内の血流シミュレーション(OS2-4:循環系のバイオメカニクス,オーガナイズドセッション2:循環系のバイオメカニクス)

    中山 敏男, 太田 信, RUFENACHT Daniel A., 高橋 明

    バイオエンジニアリング講演会講演論文集 2006 (0) 84-85 2007年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebio.2006.19.84  

  165. 340 消化管蠕動運動の補助を目的としたアクチュエータの開発研究(OS1-3:生物流体とバイオミメティクス,GS:一般セッション,オーガナイズドセッション1:生物流体とバイオミメティクス)

    関根 一光, 中澤 文雄, 白石 泰之, 山家 智之, 西條 芳文, 太田 信, 堀 義生, 松木 英敏, 佐藤 文博, 前田 剛

    バイオエンジニアリング講演会講演論文集 2006 (0) 336-337 2007年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebio.2006.19.336  

  166. 1128 マイクロCTを用いたラットの脳血管3次元再構築(J05-2 血液循環系のバイオエンジニアリング:医療技術への展開(2),J05 血液循環系のバイオエンジニアリング:医療技術への展開)

    太田 信, 中山 敏男, 何 川, 高橋 明

    年次大会講演論文集 2007 (0) 95-96 2007年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmemecjo.2007.6.0_95  

    詳細を見る 詳細を閉じる

    The cerebral arteries in rats are reconstructed and the blood flow dynamics are performed by micro-CT for investigating cerebral aneurysms such as mechanism of generation, growing, and rupture of aneurysm. The cerebral arteries in rats were extracted from the brain by using cast techniques. The 3-D reconstruction of arteries by micro-CT indicates the possibilities of computational flow dynamics (CFD). The contrast media was injected from the external carotid artery into the cerebral arteries. The blood flow flushing the contrast media in cerebral arteries observed by micro-CT may allow the trace of blood flow using the cinematic angiography method, if the time resolution increases.

  167. 156 傾斜遠心顕微鏡による皮膜基板上の赤血球の摩擦特性計測(バイオエンジニアリングI)

    神取 孝司, 井上 浩介, 早瀬 敏幸, 高木 敏行, 竹野 貴法, 太田 信, 武田 元博

    東北支部総会・講演会 講演論文集 2007 (0) 111-112 2007年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmeth.2007.42.111  

  168. 158 シネマティックアンギオグラフィにオプティカルフロー法を適用した血流の定量測定法開発(バイオエンジニアリングI)

    恩田 一寿, 太田 信

    東北支部総会・講演会 講演論文集 2007 (0) 115-116 2007年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmeth.2007.42.115  

  169. 161 脈診の数値モデル構築のための基礎的研究(バイオエンジニアリングII)

    鳴海 賢太郎, 仁田 新一, 中西 勉, 劉 磊, 白井 敦, 早瀬 敏幸, 太田 信, 金野 敏, 川田 浩, 丸山 満也

    東北支部総会・講演会 講演論文集 2007 (0) 121-122 2007年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmeth.2007.42.121  

  170. 脳動脈瘤内の血流に対するステントデザインの影響

    中山敏男, 太田信, RUEFENACHT Daniel A, 高橋明

    日本生体医工学会大会プログラム・論文集(CD-ROM) 46th ROMBUNNO.PS1-6-6 2007年

  171. カテーテルシミュレータの開発 : 第1報, ガイドワイヤ・血管の特性の評価

    高嶋 一登, 大田 慎三, 太田 信, 葭仲 潔, 池内 健

    日本機械学会論文集. C編 72 (719) 2137-2145 2006年7月25日

    出版者・発行元:一般社団法人日本機械学会

    ISSN:0387-5024

    詳細を見る 詳細を閉じる

    We have developed catheter simulation system in blood vessels for surgical planning and intraoperative assistance. In this study, we evaluated the effect of the fundamental parameters of the guidewire and blood vessel models for the simulation system. The model of the guidewire was constructed with viscoelastic springs and segments to avoid complicated mathematical procedures as the dynamic deformation of a flexible structure. The vessel is an elastic circular cylinder, whose shape is defined by the centerline and the radii. Collisions between the guidewire and the vessel are calculated and the contact forces are determined according to the stiffness, damping and friction of the vessel wall. Using these models, the trajectory of the guidewire tip and the reaction force were calculated. When friction coefficient between the guidewire and the vessel is large, the guidewire tip vibrates. When deformation property of the vessel is changed, the trajectory of guidewire tip also changes. Bending of the guidewire tip decreases the reaction force at bending points of the vessel. When the guidewire becomes stiffer, the deformation of the vessel becomes large. These findings should facilitate determination of the parameters of the simulation system.

  172. カテーテルシミュレータの開発(第1報,ガイドワイヤ・血管の特性の評価):第1報, ガイドワイヤ・血管の特性の評価

    高嶋 一登, 大田 慎三, 太田 信, 葭 仲潔, 池内 健

    日本機械学会論文集 C編 72 (719) 2137-2145 2006年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/kikaic.72.2137  

    ISSN:0387-5024

    詳細を見る 詳細を閉じる

    We have developed catheter simulation system in blood vessels for surgical planning and intraoperative assistance. In this study, we evaluated the effect of the fundamental parameters of the guidewire and blood vessel models for the simulation system. The model of the guidewire was constructed with viscoelastic springs and segments to avoid complicated mathematical procedures as the dynamic deformation of a flexible structure. The vessel is an elastic circular cylinder, whose shape is defined by the centerline and the radii. Collisions between the guidewire and the vessel are calculated and the contact forces are determined according to the stiffness, damping and friction of the vessel wall. Using these models, the trajectory of the guidewire tip and the reaction force were calculated. When friction coefficient between the guidewire and the vessel is large, the guidewire tip vibrates. When deformation property of the vessel is changed, the trajectory of guidewire tip also changes. Bending of the guidewire tip decreases the reaction force at bending points of the vessel. When the guidewire becomes stiffer, the deformation of the vessel becomes large. These findings should facilitate determination of the parameters of the simulation system.

  173. 528 血管内カテーテルシミュレータに関する基礎研究(GS-12 循環器工学,一般セッション,学術講演)

    高嶋 一登, 大田 慎三, 太田 信, 葭仲 潔, 池内 健

    バイオエンジニアリング講演会講演論文集 2005 (0) 355-356 2006年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebio.2005.18.355  

  174. B105 血管内カテーテルシミュレータに関する基礎研究 : 第2報,接触力算出方法の評価(B1-1 人工臓器)

    高嶋 一登, 大田 慎三, 太田 信, 葭仲 潔, 向井 利春

    バイオフロンティア講演会講演論文集 2006 (0) 49-50 2006年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebiofro.2006.17.49  

    ISSN:1348-2939

  175. B108 脈診における脈波情報の取得に関する数学モデルの構築と実験による検証(B1-2 血流・微小循環)

    鳴海 賢太郎, 丸山 満也, 白石 泰之, 仁田 新一, 中西 勉, 劉 磊, 井上 浩介, 白井 敦, 早瀬 敏幸, 太田 信, 金野 敏, 川田 浩

    バイオフロンティア講演会講演論文集 2006 (0) 55-56 2006年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebiofro.2006.17.55  

    ISSN:1348-2939

  176. 822 脳動脈瘤の3次元形状計測分析(1)(OS8-5 医療援用工学における流動ダイナミクス,OS8 医療援用工学における流動ダイナミクス,オーガナイズドセッション)

    太田 信, RUFENACHT Daniel A.

    流体工学部門講演会講演論文集 2006 (0) _822-a_ 2006年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmefed.2006._822-a_  

    ISSN:1348-2882

  177. 822 脳動脈瘤の3次元形状計測分析(2)(OS8-5 医療援用工学における流動ダイナミクス,OS8 医療援用工学における流動ダイナミクス,オーガナイズドセッション)

    太田 信, RUFENACHT Daniel A.

    流体工学部門講演会講演論文集 2006 (0) _822-1_-_822-4_ 2006年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmefed.2006._822-1_  

    ISSN:1348-2882

    詳細を見る 詳細を閉じる

    Our goal is to find the range of size of cerebral aneurysms, neck sizes, and vessel diameters based on a 3D rotational angiography (3D-RA). Measurement of 1st (A), 2nd, and 3rd axes of aneurismal cavity, the maximum and the minimum diameter of neck (N), and the diameter of parent vessel (P) were obtained from 43 cerebral aneurysms in 33 patients with use of 3D-RA (Philips Medical Systems). The most frequent place where cerebral aneurysms were found in the 43 is ICA (9) and AcomA (9). The long diameter of neck is the almost same as the short one or 1.75-fold longer than that of shorter neck. The form of aneurysm cavity was an ellipsoid which allowed calculating the volume with the three axes. The 1st axis is 0.77-fold longer than the 2nd axis and is 0.70-fold longer than the 3rd length.

  178. 1307 PVA円管モデルを用いた超音波計測融合シミュレーションの数値実験および実システムへの応用(2)(OS13-2 計測とシミュレーションの融合,OS13 計測とシミュレーションの融合,オーガナイズドセッション)

    劉 磊, 井上 浩介, 早瀬 敏幸, 太田 信

    流体工学部門講演会講演論文集 2006 (0) _1307-1_-_1307-4_ 2006年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmefed.2006._1307-1_  

    ISSN:1348-2882

    詳細を見る 詳細を閉じる

    Thoracic aortic dissection has a high fatality rate, and the number of fatalities has tendency to increase with advancing age. Because of our fast-aging society, it is a problem calling for immediate solution. It is difficult to recognize the exact structure of the 3D blood flow with measurement existing. Besides, because we cannot set precise boundary condition of living body, computer simulation is not a complete tool to analyze real blood flows. Our research group had propounded a new solution, integrating together ultrasonic-measurement and CFD to investigate blood flows, which is called Ultrasonic-Measurement-Integrated (UMI) Simulation. Usability of UMI simulation has been confirmed by numerical experiment in former studies. In this report, experimental system consisting of a PVA hydro-gel straight pipe model and constant head flow tank was developed, and fundamental experiment to confirm the performance of the ultrasound measurement device was performed. In parallel with experiment, a numerical experiment with axisymmetric straight pipe model was performed. In this report, we confirmed characteristics of the ultrasound measurement to the PVA model in experiment and usability of the UMI simulation in numerical experiment.

  179. 脳動脈瘤の3次元形状計測分析

    太田信, RUEFENACHT Daniel A

    日本機械学会流体工学部門講演会講演論文集(CD-ROM) 84th ROMBUNNO.822 2006年

    ISSN:1348-2882

  180. 病気の治療と工学の役割

    太田 信

    仙台市医師会会報 497 3-7 2005年11月

    出版者・発行元:仙台市医師会

  181. モデルを用いた,脳動脈瘤内の血流変化におけるステントの影響

    太田信, 藤村直子, AUGSBURGER Luca, WETZEL Stephan, YILMAZ Hasan, ABDO German, LOVBLOD Karl‐Olof, BARATH Krisztina, RUEFENACHT Daniel A

    日本流体力学会年会講演論文集 2005 224 2005年9月5日

    ISSN:1342-8004

  182. 病気の治療と向き合う工学を目指して

    太田 信

    まなびの杜 32 (Summer) 4-5 2005年6月30日

    出版者・発行元:東北大学

  183. 1107 Cinematic Angiographyを用いた脳動脈瘤内の血流測定法の開発(S14-2 制御と情報・生体への応用(2),S14 制御と情報・生体への応用)

    太田 信, 藤村 直子, 岩田 博夫, 堤 定美, ルフナハト ダニエル

    年次大会講演論文集 2005 (0) 87-88 2005年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmemecjo.2005.5.0_87  

    詳細を見る 詳細を閉じる

    Image guided minimally invasive treatments for cerebral aneurysms have been popular for last decade. The implantation such as coil or stent reduces the flow in the cavity and the cinematic angiography (CA) has a potentiality for measuring the flow speed during a treatment. In this paper, we applied the CA with 25f/s to a real cerebral aneurysm to take successive images and measured the flow speed in the cavity. Two usual angles of Posteroanterior (PA) and Lateral (LA) projections were selected and images are taken simultaneously. The condition of CA was 60kV and 300mA. The left-convolution flow was observed form the viewpoint of PA and around 50mm/s. The inflow from the parent artery was rotated with the counterclockwise in the aneurysm. The speed of inflow was 359mm/s and reduced in the cavity. The CA is possible to measure the flow speed in aneurysm.

  184. AM05-17-008 モデルを用いた、脳動脈瘤内の血流変化におけるステントの影響(生物流体・生体流体2,一般講演)

    太田 信, 藤村 直子, AUGSBURGER Luca, WETZEL Stephan, YILMAZ Hasan, ABDO German, LOVBLOD Karl-Olof, BARATH Krisztina, RUEFENACHT Daniel A.

    日本流体力学会年会講演論文集 2005 224-224 2005年

    出版者・発行元:日本流体力学会

    詳細を見る 詳細を閉じる

    Endovascular stent implantation is used for treating cerebral aneurysms by reducing flow in the cavity and the evaluation of stent will be performed by measurements of flow speed. The impact of stent on the blood flow may depend on the design of stent strut. In this study, two stents (Stent A has larger slit and bigger diameter of the strut than Stent B) with similar geometries were prepared. The inflow zone was created at the distal neck and the zone of Stent B included the stent struts, whereas the inflow zone of Stent A was in their two struts. The flow speed measured by SVC method exhibits the speed of stent B was decreased, while that of Stent A was higher than no stent. The capability of the stent for reducing flow into the cavity will depend on the strut diameter and the opened cell on the inflow zone.

  185. AM05-17-011 超音波計測融合シミュレーション検証のための大動脈内血流模擬実験装置(生物流体・生体流体3,一般講演)

    劉 磊, 井上 浩介, 早瀬 敏幸, 太田 信

    日本流体力学会年会講演論文集 2005 227-227 2005年

    出版者・発行元:日本流体力学会

    詳細を見る 詳細を閉じる

    Thoracic aortic dissection has a high fatality rate, and the number of fatalities is tendency to increase with advancing age. Because of our fast-aging society, it's a problem calling for immediate solution. It's difficult to recognize the exact structure of the 3D blood flow with measurement existing, and that makes having an elucidation of mechanism adversity. Our research group had propounded a new solution; integrate together ultrasonic-measurement and CFD to investigate blood flow, which is called Ultrasonic-Measurement-Integrated (UMI) Simulation. Usability of UMI simulation has been confirmed by numerical experiment in former studies. In this paper,_<in-vitro> system for fluid flow experiment to verify UMI simulation was fabricated and pilot study was performed. Thoracic aneurysm models in this system, based on CT scan data and duplicated its original configuration precisely, were made of Silicone rubber and PVA-polymer. The letter models has elasticity like real vessels is a point worthy of special mention.

  186. 28aWD-1 嚢状脳動脈瘤流れにおけるステントの特性解析(流体運動と安定性(層流・渦・安定性))(領域11)

    平林 美樹, 太田 信, Rufenacht Daniel A., Chopard Bastien

    日本物理学会講演概要集 59 (0) 282-282 2004年

    出版者・発行元:一般社団法人 日本物理学会

    DOI: 10.11316/jpsgaiyo.59.1.2.0_282_3  

    ISSN:1342-8349

  187. 29aWE-13 嚢状脳動脈瘤内流れのステント留置による減速メカニズムに関する数値解析

    平林 美樹, 太田 信, Rufenacht Daniel A., Bastien Chopard

    日本物理学会講演概要集 58 (0) 277-277 2003年

    出版者・発行元:一般社団法人 日本物理学会

    DOI: 10.11316/jpsgaiyo.58.1.2.0_277_1  

    ISSN:1342-8349

  188. 圧縮配向結晶化超高分子量ポリエチレンの耐摩耗性と力学的性質(<特集>高分子材料)

    太田 信, 玄 丞烋, 姜 有峯, 岡 正典, 堤 定美, 村上 昌三, コウジ]谷 信三

    材料 49 (12) 1301-1305 2000年12月15日

    出版者・発行元:社団法人日本材料学会

    ISSN:0514-5163

    詳細を見る 詳細を閉じる

    In order to improve the wear properties of artificial joints, a slightly cross-linked ultra high molecular weight polyethylene(UHMWPE)was compressed at molten state and crystallized by cooling to room temperature. The molecular chain of the UHMWPE was orientated to the direction of deformation.Density and melting point of the mold article were increasd in accordance with compression ratio.The α_c peak of loss modulus was shifted to higher temperature compared with the non-compressed sample.And it was also revealed that the weight loss of the compressed UHMWPE was remarkably less than that of a non-compressed sample from the result of the pin-on-disc wear test.

  189. MR Elastographyを用いた生体組織弾性率の定量測定

    菅 幹生, 大城 理, 湊 小太郎, 松田 哲也, 高橋 隆, 太田 信, 堤 定美, 岡本 淳, 滝沢 修

    医療情報学連合大会論文集 20 532-533 2000年11月23日

  190. 超高速MRIを用いた顎運動計測

    東 高志, 南部 敏之, 土肥 健二, 太田 信, 堤 定美, 井上 博志, 林 浩二, 伊藤 仁, 真多 俊博, 久津木 学

    日本臨床バイオメカニクス学会誌 = Proceedings of ... Annual Meeting of Japanese Society for Clinical Biomechanics and Related Research 21 489-496 2000年10月1日

    ISSN:1340-9018

  191. MR Elastography 法を用いた局所弾性率の計測と評価

    菅 幹生, 大城 理, 湊 小太郎, 松田 哲也, 太田 信, 堤 定美, 高橋 隆, 岡本 淳, 滝沢 修

    Medical imaging technology 18 (4) 385-386 2000年7月25日

    ISSN:0288-450X

  192. 生体軟組織の弾性率測定用標準物質としてのPVAゲルの開発と測定

    太田 信, 津田 裕子, 東 高志, 南部 敏之, 玄 丞烋, 堤 定美, 今井 麻紀, 小森 優, 松田 哲也, 高橋 隆, 菅 幹生, 湊 小太郎

    Medical imaging technology 18 (4) 393-394 2000年7月25日

    ISSN:0288-450X

  193. 低周波共振法による生体軟組織の粘弾性測定

    箕浦 哲嗣, 坂井 信幸, 永田 泉, 太田 信, 津田 裕子, 堤 定美

    Medical imaging technology 18 (4) 395-396 2000年7月25日

    ISSN:0288-450X

  194. "MREを用いた剛性率と粘性率の計測",Medical Imaging Technology 査読有り

    大城 理, 菅 幹生, 太田 信, 松田 哲也, 堤 定美, 湊 小太郎, 千原 國宏, 高橋 隆

    1998年

  195. 微弱な超音波エコー信号検出のための Wald の逐次検定法の改良

    太田 信, 西村 営三, 堤 定美

    電子情報通信学会技術研究報告. US, 超音波 96 (320) 53-58 1996年10月22日

    出版者・発行元:一般社団法人電子情報通信学会

    詳細を見る 詳細を閉じる

    単一の閾値判別では困難なほどの微弱なエコー信号の検出に, 閾値を二つ用いて信号検定を行うWaldの逐次検定法に加算平均などの改良を行い, 評価を行った. その結果, 改良前と比べ信号検出の正確性と検出回数に大幅な改善が見られた. またS/N比の違う矩形型の信号をノイズのみの波形に加え, 改良したWaldの検定法の実用可能なS/N比を調べた. これより, SN比が5.5db(約1.9倍)程度以上で, 90%以上の信頼性が得られることが分かった.

  196. 3)仮想現実感技術を応用した教育用シミュレータの開発 : 歯科臨床における医療技術伝承のための試み(ヒューマンインフォメーション研究会)

    南部 敏之, 阿部 昌代, 太田 信, 西村 営三, 提 定美

    テレビジョン学会誌 50 (2) 319-319 1996年2月20日

    出版者・発行元:一般社団法人映像情報メディア学会

    ISSN:0386-6831

  197. 仮想現実感技術を応用した教育用シミュレータの開発 : 歯科臨床における医療技術伝承のための試み

    南部 敏之, 阿部 昌代, 太田 信, 西村 営三, 堤 定美

    テレビジョン学会技術報告 19 (47) 13-18 1995年

    出版者・発行元:一般社団法人 映像情報メディア学会

    DOI: 10.11485/tvtr.19.47_13  

    ISSN:0386-4227

    詳細を見る 詳細を閉じる

    In this age of advanced and complicated clinical dentistry, knowledge acquisition through books and training methods using mannikins cannot provide adequate training results. With Virtual Reality (VR) system, our approach is to develop a "therapeutic simulator" whereby the skill of remedy of expert dentists can be inherited intuitively by dental trainees. The digitizer has 7 links with 7 degrees of freedom like the human arm, and an electric rotary encoder was set to evaluate the movement of the handpiece with accuracy better than 0.5mm. The application of virtual reality provides the advantages of 1) supplementing intermediate and mannikin-based training in the process of practical education, 2) enables training in abnormal cases as when the patient's tongue moves suddenly, and 3) enables three-dimensional recording of the process of tooth cutting, which can be played back later for review. This study was supported by the Grant-in-Aid for Scientific Research from the Ministry of Education, Science and Culture in Japan (No. (A) (1) 05507004).

︎全件表示 ︎最初の5件までを表示

書籍等出版物 5

  1. 脳神経外科の最新医療

    太田 信, Daniel A. Rüfenacht, 堤 定美

    先端医療技術研究所 2004年9月

  2. 「医療材料・医療機器の安全性と適合性」

    太田 信, 半田 明, Rufenacht, D.A, 堤 定美

    CMC出版 2003年11月28日

  3. Computational Science-ICCS

    M. Hirabayashi, M. Ohta, D. A. Ruefenacht, B. Chopard

    P.M.A 2003年1月

  4. Joint Arthroplasty

    M. Oka, S.-H. Hyon, Makoto Ohta, T. Nakamura, Y. Ushio, J.Toguchida

    Springer-Verlag Tokyo 1999年1月

  5. Adv. in Polym. Biomate. Sci

    Suong-Hyu Hyon, Makoto Ohta, Masanori Oka, Sadami Tsutsumi

    1997年1月

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  1. 超音波検査用バイオモデル材料のPVA-H 3Dプリンタへの応用

    小池隼太, Shiddiq Hashuro, 小林直裕, Simon Tupin, 小助川博之, 戸塚厚, 太田信

    日本機械学会東北支部 第56期総会・講演会 2021年3月12日

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    神 容慶, 北村 洸, 太田 信, 安西 眸, 麦倉 俊司, 森 菜緒子

    第54回 日本生体医工学会東北支部大会, 2021年1月23日

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    Kazuki Takeda, Hitomi Anzai, Mingzi Zhang, Kohei Mitsuzuka, Wang Haoran, Ai Kajiyama, Makoto Ohta

    2ND INTERNATIONAL SYMPOSIUM ON COMPUTATIONAL BIOFLUID 2020 2020年12月16日

  5. The influence brought by specific boundary conditions on vascular simulations

    Fangjia Pan, Makoto Ohta, Hitomi Anzai, Shunji Mugikura, Naoko Mori

    2ND INTERNATIONAL SYMPOSIUM ON COMPUTATIONAL BIOFLUID 2020 2020年12月16日

  6. WSS and Frequency Characteristics in Patient-Specific Aneurysm in MCA

    Ryuhei Yamaguchi, Tomoaki Yamazaki, Nadia Shaira Shafii, Gaku Tanaka, Makoto Ohta

    2ND INTERNATIONAL SYMPOSIUM ON COMPUTATIONAL BIOFLUID 2020 2020年12月16日

  7. A study on Optical Flow Method for Hemodynamics Estimation

    Yutaro Kohata, Hitomi Anzai, Makoto Ohta, Meghane Decroocq, Carole Frindel, Simon RIT

    2ND INTERNATIONAL SYMPOSIUM ON COMPUTATIONAL BIOFLUID 2020 2020年12月16日

  8. One way characteristics in Patient Specific Aneurysm in MCA

    Nadia Shaira Shafii, Ryuhei Yamaguchi, Ahmad Zahran, Md Khudzari, Makoto Ohta, Kahar Osman

    2ND INTERNATIONAL SYMPOSIUM ON COMPUTATIONAL BIOFLUID 2020 2020年12月16日

  9. Flow characteristics in Full-scale Patient Specific Aneurysm in Basilar Artery

    Tomoaki Yamazaki, Ryuhei Yamaguchi, Gaku Tanaka, Makoto Ohta

    2020年12月16日

  10. 血管内治療デバイス留置シミュレータの開発 (デバイスパラメータの影響)

    太田 寛人, 高嶋 一登, 芳賀 洋一, 戴 晨鳴, 太田 信, 庄島 正明

    日本機械学会 第31回バイオフロンティア講演会

  11. Development and Eveluation of PVA-H 3D Printed Blood Vessel Biomodels with Several Stiffness

    Naohiro Kobayashi, Ryota Nagano, Makoto Ito, Yasutomo Shimizu, Simon Tupin, Makoto Ohta

    International Mechanical Engineering Congress and Exposition IMECE2020

  12. Implementation of Computer Simulation to Assess Flow−Diversion Treatment Outcomes— Systematic Review and Meta−Analysis 招待有り

    Mingzi Zhang, Simon Tupin, Hitomi Anzai, Yutaro Kohata, Massaki Shojima, Kosuke Suzuki, Yoshihiro Okamoto, Katsuhiro Tanaka, Takanobu Yagi, Soichiro Fujimura, Makoto Ohta

  13. CFD Analysis of The Effect of Flush Flow Condition on Angiopscopy Visibility

    Kohei Mitsuzuka, Yujie Li, Toshio Nakayama, Hitomi Anzai, Wang Haoran, Makoto Ohta, Simon Tupin

    17th International Conference on Flow Dynamics,

  14. Permeability-Microstructure Relationship in Cancellous Bone

    Simon Tupin, Makoto Ito, Makoto Ohta

    17th International Conference on Flow Dynamics,

  15. 生体組織モデルを用いた医療機器開発へ参加のお誘い 招待有り

    太田 信, Tupin Simon, 安西 眸, 于 凱鴻, Zhang Mingzi, 戸塚 厚, 小助川博之

    第61回 日本脈管学会総会

  16. Implementation of Computer Simulation to Assess Flow−Diversion Treatment Outcomes — Systematic Review and Meta−Analysis 招待有り

    Mingzi Zhang, Simon Tupin, Hitomi Anzai, Yutaro Kohata, Massaki Shojima, Kosuke Suzuki, Yoshihiro Okamoto, Katsuhiro Tanaka, Takanobu Yagi, Soichiro Fujimura, Makoto Ohta

    CFD-Bio, 日本機械学会バイオエンジニアリング部門 制御と情報-生体への応用研究会 脳神経血管内治療に関する医工学連携研究会 2020年10月5日

  17. Development of Transparent PVA-H Model with Scattering Ability for Ultrasound Usage

    Muhammad Shiddiq Sayyid Hashuro, Simon Tupin, Daisuke Goanno, Makoto Ito, Kosuke Inoue, Toshiyuki Hayase, Makoto Ohta

    14th International Symposium on Advanced Biomedical Ultrasound 2020 2020年9月23日

  18. マイクロセンサを搭載した血管モデル

    戴 晨鳴, 吉田 洋, 松永忠雄, 鶴岡典子, 于 凱鴻, 清水康智, 太田 信, 庄島正明, 高嶋一登, 原田香奈子, 益田泰輔, 新井史人, 芳賀洋一

    生体医工学シンポジウム2020 2020年9月18日

  19. (骨)モデルの国際標準を進めるWG14への参加の勧め 招待有り

    太田 信

    医用立体モデルコンソーシアム 2020年度総会・講演会 2020年7月30日

  20. Flow characteristics in a deformable full-scale patient-specific cerebral aneurysm

    Gaku Takizawa, Tomohiro Yamazaki, Nadia S. Shafii, Ryuhei Yamaguchi, Gaku Tanaka, Simon Tupin, Shiddiq Hashuro, Kahar Osman, Makoto Ohta

    2020 Summer Biomechanics, Bioengineering and Biotransport Conference (SB³C2020) 2020年6月18日

  21. Endothelial Cells Distribution on the Stent Strut with Surface Treatment after the Flow Exposure

    Zi Wang, Narendra Kurnia Putra, Kako Yamasaki, Naofumi Ohtsu, Hisatoshi Kobayashi, Makoto Ohta

  22. 4次元血管造影法に基づく脳底動脈瘤における血流挙動の数値解析

    山崎智皓, 岡崎陽大, 田中学, 太田信, 石田藤麿, 山口隆平

    日本機械学会バイオフロンティア講演会講演論文集(CD-ROM) 2020年

  23. 変形を伴う中大脳動脈瘤内流れの挙動

    池谷直紀, 山崎智皓, 田中学, 太田信, 山口隆平

    日本機械学会バイオフロンティア講演会講演論文集(CD-ROM) 2020年

  24. 血管内治療デバイス留置シミュレータの開発(コイル接触力とカテーテルの動作の評価)

    大石卓弥, 高嶋一登, 葭中潔, YU Kaihong, 太田信, 森浩二, 当麻直樹

    日本機械学会バイオフロンティア講演会講演論文集(CD-ROM) 2020年

  25. マイクロセンサを搭載した脳血管モデル

    芳賀洋一, 芳賀洋一, 吉田洋, 松永忠雄, 清水康智, 太田信, 太田信, 庄島正明, 益田泰輔, Yu Kaihong, Simon Tupin, Dai Chenming, 新井史人, 原田香奈子

    電気学会論文誌 E 2020年

  26. コイル塞栓術における脳血管内治療医の注視点の特徴と経験症例数との関係

    岡本吉弘, 庄島正明, 新妻邦泰, 太田信, 植松美幸, 迫田秀行, 配島由二

    人工臓器(日本人工臓器学会) 2020年

  27. バイオニックヒューマノイドプラットフォームと要素技術の成果

    益田 泰輔, 太田 信, 芳賀 洋一, 光石 衛, 原田 香奈子, 新井 史人, 小俣 誠二, 相原 一, 森田 明夫, 金 太一, 齊藤 延人, 山下 樹里, 鎮西 清行, 福田 敏男

    生体医工学 2019年

    詳細を見る 詳細を閉じる

    <p>我々はリアリティの高い人体シミュレータを実現し,手術トレーニングやデバイス評価環境を構築するために,生体と類似する物理特性を再現し,センサやアクチュエータと言った能動的な機能デバイスを組み込んだ人体シミュレータ「バイオニックヒューマノイド」を提案している.そのバイオニックヒューマノイドの構造および特徴を有するプラットフォームとして,眼科手術(Bionic-EyE:BE)・脳外科手術(Bionic-Brain:BB)・血管内手術(Bionic-Vasculature:BV)に対応したそれぞれの専用プラットフォームを開発した.ここでは,各プラットフォームの紹介と,数ミクロンレベルの内境界膜(ILM)剥離モデルの作製,ミクロン繊維の不織布とエラストマー材料を交互に積層させた線維柱体モデルの作製,鼻腔・下垂体周辺モジュールの作製,フレキシブル圧電センサによる手術手技評価などの各要素技術の成果について報告する.</p>

  28. PIVを用いた血管内視鏡周りのフラッシュ流れ解析

    三塚康平, TUPIN Simon, LI Yujie, 中山敏男, 太田信

    日本機械学会バイオフロンティア講演会講演論文集(CD-ROM) 2019年

  29. MRA画像を用いた脳底動脈形状の標準化

    北村洸, 麦倉俊司, 太田信, 安西眸

    日本機械学会バイオフロンティア講演会講演論文集(CD-ROM) 2019年

  30. 脳動脈瘤コイル留置のシミュレーション-目的と課題-

    当麻直樹, 高嶋一登, 太田信, 森浩二

    脳血管内治療(Web) 2019年

  31. 脳動脈瘤コイル留置のシミュレーション-手法と応用例-

    高嶋一登, 当麻直樹, 太田信, 森浩二

    脳血管内治療(Web) 2019年

  32. 弾性変形を伴う実脳動脈瘤内流れの挙動

    滝澤岳, 田中学, TUPIN Simon, 太田信, 山口隆平

    バイオエンジニアリング講演会講演論文集(CD-ROM) 2019年

  33. Research on Arterial Stiffness in Type 2 Diabetic Patients Based on Pulse Wave Analysis

    Gaoyang Li, Xiaorui Song, Aike Qiao, Makoto Ohta

    15th ICFD (Internatinal Conference of Fluid Dynamics 2018年11月

  34. Hemodynamic Study on Coronary Artery Aneurysms with Bypass Surgery

    Haoran Wang, Hitomi Anzai, Makoto Ohta, Youjun Liu

    15th ICFD (Internatinal Conference of Fluid Dynamics) 2018年11月

  35. Permeability studies for the improvement of medical devices

    Simon Tupin, Makoto Ito, Makoto Ohta

    15th ICFD (Internatinal Conference of Fluid Dynamics) 2018年11月

  36. Compliance effect on the flow condition in vascular in vitro experiments

    Masami Matsuura, Simon Tupin, Makoto Ohta

    ASME 2018 International Mechanical Engineering Congress and Exposition 2018年11月

  37. 3Dプリンタを用いたPVA‐H血管モデル作製用複合機の開発(第一報)

    長野凌太, 清水康智, 吉田洋, 松永忠雄, 葛迫淳一, 木原信宏, 芳賀洋一, 太田信

    日本シミュレーション外科学会会誌 2018年10月

  38. バイオニックヒューマノイドの開発と評価

    山下樹里, 原田香奈子, 太田信, 鎮西清行

    ヒューマンインタフェースシンポジウム論文集(CD-ROM) 2018年9月5日

  39. Characteristics of Elasticity on Flow Behavior in Middle Cerebral Aneurysm Model

    Ryuhei Yamaguchi, Gaku Tanaka, Taihei Kotani, Kahar Osman, Nadia Shafii, Hitomi Anzai, Makoto Ohta

    8th World Congress of Biomechanics 2018年7月

  40. Dose hypertension history affect morphology or hemodynamic characteristics of Cerebrobasilar System? Retrospetive study of 249 patients diagnosed with hypertension.

    Yujie Li, Mingzi Zhang, Ko Kitamura, Hitomi anzai, Shuji Mugikura, Makoto Ohta

    8th World Congress of Biomechanics 2018年7月

  41. PIV MEASUREMENT IN AN IDEAL ANEURYSMAL MODEL USING A TRANSPARENT COIL MODEL

    Makoto OHTA, Masanori KUZE, Simon TUPIN, Kaihong YU, Yasutomo SHIMIZU, Hitomi ANZAI

    Conference on Modelling Fluid Flow (CMFF’18) 2018年7月

  42. FBGセンサによる非侵襲多機能バイタルサイン検知原理の解明

    ウェアラブルバイタルサイン測定システム開発プロジェクト,第一回公開講演会 2016年12月9日

  43. 脳血管内治療デバイスと治療の有効性を予測する血管モデルの開発

    脳神経血管内治療学会,ものづくりコモンズジョイントシンポジウム 2016年11月26日

  44. 脳動脈瘤の生化学的イベントと数値流体解析の応用に関するCutting-Edge 国際会議

    脳神経血管内治療学会,機械学会バイオエンジニアリング部問共同 研究会「脳神経血管内治療に関する医工学連携研究会」,国際頭蓋内 ステント学会 共同シンポジウム 2016年11月26日

  45. In Vitro Experimental Evaluation for Radiofrequency Ablation: Electrode Temperature and Lesion Size of Ablation with Open Irrigation Cooling 国際会議

    3rd Biomedical Science and Technology Symposium (Macquarie-Tohoku Symposium) 2016年11月9日

  46. BioModels 国際会議

    3rd Biomedical Science and Technology Symposium (Macquarie-Tohoku Symposium) 2016年11月5日

  47. Modeling of cerebral vascular diseases 国際会議

    3rd Biomedical Science and Technology Symposium (Macquarie-Tohoku Symposium) 2016年11月5日

  48. Stent Evaluation in vitro: Towards Next Generation of Biomodels 国際会議

    3rd Biomedical Science and Technology Symposium (Macquarie-Tohoku Symposium) 2016年11月5日

  49. An Investigation on the Effect of Vessel Wall Deformation on Blood Flow and Wall Shear Stress 国際会議

    13th International IntraCranial Stent Meeting 2016年11月

  50. Blood Flow Into Basilar Tip Aneurysms A Predictor for Recanalization After Coil Embolization 国際会議

    13th International IntraCranial Stent Meeting 2016年11月

  51. Computer simulation of intracranial stent deployment 国際会議

    13th International IntraCranial Stent Meeting 2016年11月

  52. Correlating MR Wall Enhancement and Wall Shear Stress: Does CFD work to predict aneurysm instability? 国際会議

    13th International IntraCranial Stent Meeting 2016年11月

  53. Exploring the relationship between the inflow zone and strut positions within the aneurysm orifice: a hemodynamic simulation study (P35) [ 国際会議

    13th International IntraCranial Stent Meeting 2016年11月

  54. Haemodynamic Simulation of Aneurysm Treated with Virtual Flow Diverter 国際会議

    13th International IntraCranial Stent Meeting 2016年11月

  55. Hemodynamic Simulation for Cerebrovascular Stent 国際会議

    3rd Biomedical Science and Technology Symposium (Macquarie-Tohoku Symposium) 2016年11月

  56. Which Stent Diameter and Compaction Ratio Would Benefit the Patient the Most? A Computer Simulation of Virtual Stent Deployment for Treatment Rehearsal 国際会議

    3rd Biomedical Science and Technology Symposium (Macquarie-Tohoku Symposium) 2016年11月

  57. Development of an In Vitro Test Platform for the Quantitative Evaluation of Stent Devices and their Deployment 国際会議

    Thirteenth International Conference on Flow Dynamics 2016年10月11日

  58. Comparison Study of Blood Flow Pattern Changes due to the Blood Vessel Deformation during Intravascular Stent Deployment 国際会議

    TFC ELyT Workshop 2016 2016年10月

  59. Drilling under constant feed rate for bone biomodel made of acrylic composites 国際会議

    TFC ELyT Workshop 2016 2016年10月

  60. Evaluation of Tissue Heating for Radiofrequency Ablation Using a Vibrating Catheter 国際会議

    TFC ELyT Workshop 2016 2016年10月

  61. Hemodynamic Behaviors under Blood Vessel Deformation by Stent Struts: Two Dimensional Study. 国際会議

    Thirteenth International Conference on Flow Dynamics 2016年10月

  62. In-vitro evaluation of the effect of a multi-layer stent device deployment on the aorta-renal artery bifurcation hemodynamics 国際会議

    ElyT workshop 2017 2016年10月

  63. Radiofrequency Ablation: Lesion Size Measurement on Agar Phantom 国際会議

    TFC ELyT Workshop 2016 2016年10月

  64. Introduction of Evaluation of Endoleak in Ink Flow Study

    生体医工学シンポジウム2016 2016年9月

  65. Material Investigation for the study of drilling bone biomodel 国際会議

    3rd International Conference on BioTribology (ICoBT 2016) 2016年9月

  66. 擬似血液を用いた振動カテールアブレション周りのPIV計測

    LIFE2016 2016年9月

  67. 血管内治療のための血管モデル開発

    日本機械学会 2016 年度年次大会 2016年9月

  68. 流れ中における内皮化促進のための表面処理に関する研究

    日本流体力学会年会2016 2016年9月

  69. 力学的、熱力学的機能性を付与した生体組織モデル(バイオモデル)の開発と応用

    第12回東北大学 REDEEM シンポジウム 2016年9月

  70. Introduction of a flow rate and pressure controlled in vitro model to evaluate stent deployment effects to blood flow

    東北大学-信州大学共催シンポジウム 2016年8月3日

  71. 医療デバイス設計のための形状最適化とCFD

    第20回 流体科学におけるバイオ・医療に関する講演会 2016年6月15日

  72. AVEC CFD 2016

    第39回日本バイオレオロジー学会年会 2016年6月

  73. Development of In-vitro Model for Evaluation of Endoleak and Migration on Stent Graft 国際会議

    VII European Congress on Computational Methods in Applied Sciences and Engineering 2016年6月

  74. 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

    第39回日本バイオレオロジー学会年会 2016年6月

  75. Distribution on Endothelial Cells Downstream of a Stent Strut: An In-vitro Study 国際会議

    VII European Congress on Computational Methods in Applied Sciences and Engineering 2016年5月9日

  76. Optimal Interval of two struts relative to aneurysm inflow 国際会議

    VII European Congress on Computational Methods in Applied Sciences and Engineering 2016年5月9日

  77. Endothelialization on NiTi wire with immobilization of collagen using HMDI 国際会議

    10th World Biomaterials Congress 2016年5月

  78. Impact of Mechanical Vibration RF Ablation Compared with Conventional RF Ablations 国際会議

    Heart Rhythm Society’s 37th Annual Scientific Sessions 2016年5月

  79. 振動カテーテルを用いてカテーテルアブレーション中の接触力による影響

    第53回 日本伝熱シンポジウム 2016年5月

  80. 血管モデルの開発

    医工連携セミナー(先端医用機器開発) 2016年3月17日

  81. Development of a new catheter for selective venous sampling 国際会議

    ECR, 2016] 2016年3月

  82. カテーテルアブレーション評価に用いる血液の粘度を考慮した作動流体の開発

    機械学会東北支部 2016年3月

  83. Material and Surface Design for Medical Application 国際会議

    JSPS Core-to-core program, International research core on smart layered materials and structures for energy saving 2016年1月20日

  84. ステントグラフトのエンドリークおよびマイグレーション評価用 in-vitro モデルの開発

    第28回バイオエンジニアリング講演会 2016年1月

  85. せん断応力を負荷した内皮細胞の TGF-β1 が共存培養モデル内平滑筋細胞の形質に与える影響

    第28回バイオエンジニアリング講演会 2016年1月

  86. 動脈瘤ネックの流入領域に対するストラットの相対位置が瘤内流れに与える影響

    第28回バイオエンジニアリング講演会 2016年1月

  87. 非侵襲血圧計測機器開発のための血管モデル

    ウェアラブルバイタルサイン測定システム開発プロジェクト特別講演会 2015年12月7日

  88. Comparsion of Drilling Behavior of Acrylic Materials Measured by Tribometer 国際会議

    Beijing-Tohoku Biomechanics Symposium 2015年11月25日

  89. Development of in-vitro and in-silico model for evaluating medical devices 国際会議

    Beijing-Tohoku Biomechanics Symposium 2015年11月25日

  90. Optimization of Flow Diverter design 国際会議

    Beijing-Tohoku Biomechanics Symposium 2015年11月25日

  91. Biofluid Control 国際会議

    Proceedings of 2nd Biomedical Symposium and 1st Biomedical Engineering Symposium 2015年11月16日

  92. Co-relationship between Hemodynamics and Optimal Stent Structure 国際会議

    Proceedings of 2nd Biomedical Symposium and 1st Biomedical Engineering Symposium 2015年11月16日

  93. Hemodynamics Study with In-Vitro Aneurysm Phantom 国際会議

    Proceedings of 2nd Biomedical Symposium and 1st Biomedical Engineering Symposium 2015年11月16日

  94. Introduction to Graduate School of Engineering (GSE) at Tohoku University 国際会議

    Proceedings of 2nd Biomedical Symposium and 1st Biomedical Engineering Symposium 2015年11月16日

  95. In-Vitro Model and Cell Behaviors 国際会議

    Proceedings of 2nd Biomedical Symposium and 1st Biomedical Engineering Symposium 2015年11月16日

  96. Towards the Patient-specific Design of Intracranial Stents for Advanced Flow Diversion Efficacy 国際会議

    Proceedings of 2nd Biomedical Symposium and 1st Biomedical Engineering Symposium 2015年11月16日

  97. In-Vitro Model with Flow for Surface Treatment for Endothelialization 国際会議

    Interdisciplinary Cerebrovascular Symposium (Intracranial Stent Meeting 2015) 2015年11月14日

  98. The Parent Artery Configuration can Induce Flow Pattern and its Stent Pattern 国際会議

    Interdisciplinary Cerebrovascular Symposium (Intracranial Stent Meeting 2015) 2015年11月14日

  99. Analysis of Relationship Between Stent Structure and Flow Stagnation Using Self-Organizing Maps for Realistic Aneurysm 国際会議

    Interdisciplinary Cerebrovascular Symposium (Intracranial Stent Meeting 2015) 2015年11月13日

  100. Development of Evaluation System for Cardiac Ablation Catheter on Electrode Cooling and Tissue Temperature 国際会議

    International Workshop on Flow Dynamics and Spintronics 2015年11月12日

  101. 血流から考える脳動脈瘤用最適化ステントの開発

    第 9 回 CVC 千葉血管障害の原点を考える会 2015年11月5日

  102. Comparison Between CFD and MRI with 2D Velocity Vector Field and 3D Streamline in the Cerebral Aneurysm 国際会議

    Interdisciplinary Cerebrovascular Symposium (Intracranial Stent Meeting 2015) 2015年11月

  103. Visualization of Flow Patterns through the Aneurysmal Orifice after Flow Diverter Optimizations with Different Objective Functions 国際会議

    Interdisciplinary Cerebrovascular Symposium (Intracranial Stent Meeting 2015) 2015年11月

  104. 医療機器の開発に向けた海綿骨内の数値流体力学解析

    東北大学-信州大学共催シンポジウム 2015年10月23日

  105. Cell density distribution around the wire with flow condition 国際会議

    The Fifteenth International Symposium on Advanced Fluid Information 2015年10月

  106. Development of a New Catheter with Innovative Concepts for Selective Venous Sampling - Preliminary CFD Study 国際会議

    The Fifteenth International Symposium on Advanced Fluid Information 2015年10月

  107. Development of a Program for Blood flow and Cell Behaviors Based on LBM Method (third report) 国際会議

    AFI-TFI 2015年10月

  108. Research of Friction and Drilling on Bio-composite Model (third report) 国際会議

    AFI-TFI 2015年10月

  109. CFD Alanyses for the flow in Cancellous Bone with LBM 国際会議

    The 8th Asian-Pacific Conference on Biomechanics 2015年9月

  110. Lesion Size Comparison of Catheter Ablation between Open Irrigation and Vibration under No Flow Condition 国際会議

    Eighth Asian-Pacific Conference on Biomechanics 2015年9月

  111. Study of mechanical properties of acrylic composite for drilling bone biomodel 国際会議

    International Tribology Conference 2015年9月

  112. 脳動脈瘤治療用ステントにおける自己組織化マップを用いた最適形状解析

    日本機械学会2015年度年次大会 2015年9月

  113. 平均および最大流速の最適脳動脈瘤用ステントデザイン Optimized Intracranial Stent Designs with Average and Maximum Velocities

    流体力学会年会2015 2015年9月

  114. Searching for valuable hemodynamic parameters for applying to optimization study 国際会議

    9th European Solid Mechanics Conference 2015年7月7日

  115. Surface treatment on wire for increasing endothelialization 国際会議

    9th European Solid Mechanics Conference 2015年7月6日

  116. 医療機器の治験前評価法の開発

    機械的 補助循環が凝固・線溶因子に与える影響、基礎と臨床 2015年7月2日

  117. Comparison of the velocity vector field under different boundary conditions in a complex geometry with different experimental methods and numerical simulation 国際会議

    China-Japan Joint Workshop on Flow Dynamics and Transport Phenomena 2015年6月24日

  118. Comparison of the velocity vector field in a cerebral aneurysm with different methods of PIV,CFD and MRI 国際会議

    Beijing University of Technology 2015年6月23日

  119. Design analysis using optimization 国際会議

    Beijing University of Technology 2015年6月23日

  120. CFDで何をみるのか,見えるのか AVEC CFD 2015 Analysis and Visualization Exhibition of Cerebral aneurysms using CFD

    第38回日本バイオレオロジー学会年会 2015年6月

  121. Introduction of Optimization of Design using Combination of Lattice Boltzmann Method as CFD and Simulated Annealing for Reduction of Flow Speed 国際会議

    1st NUAA-Tohoku University Joint Symposium on Fluid Science, Aerospace Engineering and Smart Structure Technology 2015年6月

  122. Manufacture-Oriented Design Optimization for a Flow Diverter Stent Using Lattice Boltzmann Method and Simulated Annealing 国際会議

    11th World Congress of Structural and Multidisciplinary Optimization (WCSMO-11) 2015年6月

  123. Mechanical properties for drilling bone biomodel 国際会議

    27ème Jornées Internationals Francophones de Tribologie (JIFT2015) 2015年5月

  124. Comparison of intra-aneurysmal velocity magnitude in a patient-specific model among PIV, CFD and MRI 国際会議

    2015 ELyT lab Workshop 2015年2月20日

  125. Flow in cancellous bone 国際会議

    2015 ELyT lab Workshop 2015年2月20日

  126. Optimization of endovascular prosthesis for the treatment ofcerebral aneurysms 国際会議

    2015 ELyT lab Workshop 2015年2月20日

  127. The Effect of Vibration Ablation Catheter on the Temperature of the Electrode under 30 gf 国際会議

    2015 ELyT lab Workshop 2015年2月20日

  128. Introduction of Three Strut Optimization Strategies towards the Design of Efficient Flow-Diverter Stents 国際会議

    2015 ELyT lab Workshop 2015年2月

  129. Tohoku-Lyon collaboration, past and future 国際会議

    France-Japan research collaboration seminar(5th SciVal user conference) 2015年1月21日

  130. PIV, CFD, およびMRIにおける動脈瘤内流れ分布の比較

    日本機械学会第27回バイオエンジニアリング講演会 2015年1月

  131. Discussions of pressure distribution in artery with stenosis and aneurysm 国際会議

    ElyT 2014年2月

  132. Introduction of Design Optimization for Intracranial Stent 国際会議

    Japan-China Joint Workshop on Bio, Material and Flow Dynamics 2014年2月

  133. Model Study of Single Ventricular Heart Syndrome and its Treatment 国際会議

    ElyT 2014年2月

  134. Study of blood flow in cerebral aneurysm with coil 国際会議

    ElyT 2014年2月

  135. The Effect of Vibration Ablation Catheter on the Temperature of the Electrode under 0.1 m/s Flow 国際会議

    ElyT 2014年2月

  136. 太田研紹介

    信州大学・東北大学共催シンポジウム~感性工学と医工学の未来に向けて~ 2014年2月

  137. 外科用インプラント並びにこれに関連する器具及び計装装置の検査等に用いる力学的安全性評価用模擬骨の国際標準化

    ISO/TC150(外科用インプラント)とバイオセラミックスの国際標準化の状況 2014年1月28日

  138. アブレーションカテーテルの電極温度評価用システムの開発

    第26回バイオエンジニアリング講演会 2014年1月

  139. A Study on Multiscale Model in the presence of Systemic-to-Pulmonary Shunt utilizing Open-source CFD software Palabos 国際会議

    5TH ASIA PACIFIC CONGRESS ON COMPUTATIONAL MECHANICS & 4TH INTERNATIONAL SYMPOSIUM ON COMPUTATIONAL MECHANICS 2013年12月

  140. Hemodynamic Numerical Simulation in Artery Complicated with both Stenosis and Aneurysm in Different Shape and Position 国際会議

    5TH ASIA PACIFIC CONGRESS ON COMPUTATIONAL MECHANICS & 4TH INTERNATIONAL SYMPOSIUM ON COMPUTATIONAL MECHANICS 2013年12月

  141. Observation of filling process in injection molding for fabrication of bone biomodel 国際会議

    ICBME 2013年12月

  142. Analysis of Relationship between Lipid Environment and Protein Nanopore Properties- Toward Creation of Red Blood Cell Model with Various Membrane Strength- 国際会議

    AFI/TFI 2013年11月27日

  143. Optimized Stent 国際会議

    The 10th ICFD 2013年11月27日

  144. Membrane Channel Dynamics Depended on Lipid Environment 国際会議

    The 10th ICFD 2013年11月26日

  145. Channel Properties of Membrane Proteins on Lipid Bilayers 国際会議

    AFI/TFI 2013年11月

  146. Classification of blood flow in cerebral aneurysm considering the parent artery curves 国際会議

    ASME 2013 International Mechanical Engineering Congress & Exposition 2013年11月

  147. Classification of flow pattern in neck based considering the parent artery curves and stent implantation 国際会議

    ICS 2013 2013年11月

  148. Development of a Program for Blood flow and Cell Behaviors Based on LBM Method 国際会議

    AFI/TFI 2013年11月

  149. Development of Visualization System for Injection Molding by using PVA 国際会議

    The 10th ICFD 2013年11月

  150. Influence of Ni-Ti Wire under the Shear Stress Environment on Endothelialization 国際会議

    The 10th ICFD, Sendai 2013年11月

  151. Introduction of IFS Liaison Office Activities 国際会議

    10th ICFD 2013年11月

  152. Optimization of stent design to increase the porosity 国際会議

    ICS 2013 2013年11月

  153. PIV ANALYSIS FOR FLOW PATTERN AROUND ABLATION CATHETER TO OBSERVE THE FLOW EFFECT ON ELECTRODE 国際会議

    ASME 2013 International Mechanical Engineering Congress & Exposition 2013年11月

  154. Research of Friction and Drilling on Bio-composite Model 国際会議

    AFI/TFI 2013年11月

  155. Stagnant Blood Flow in Intracranial Aneurysms: A Possible Association with Atherosclerosis 国際会議

    The 10th ICFD 2013年11月

  156. The Effect of Vibration of Ablation Catheter on the Temperature of the Electrode 国際会議

    The 10th ICFD 2013年11月

  157. Guidewire Simulator for Intravacular Surgery 国際会議

    2013 UPM-Kyutech Symposium of Applied Engineering and Sciences 2013年10月

  158. Optimization of blood flow for intracranial stent 国際会議

    International Workshop on Flow Dynamics related to Energy, Aerospace and Material Processing KTH 2013年9月10日

  159. Density change of smooth muscle cells in co-culture model under shear stress with spatial gradient related to the development of cerebral aneurysm 国際会議

    The EMBO meeting 2013 2013年9月

  160. Electrophysiological properties of engineered FhuA ΔC/Δ4L protein nanopore affected by lipid bilayer environment 国際会議

    The EMBO meeting 2013 2013年9月

  161. Friction of Medical Materials on PVA Hydrogel in Physiological Lubrication 国際会議

    World Tribology Congress 2013 2013年9月

  162. せん断応力を負荷した共存培養モデル内の 血管平滑筋細胞からのMMPの産生量の変化

    日本機械学会2013年度年次大会 2013年9月

  163. Comparison of flow patterns around stenotic area in elastic PVA-H model and in rigid-like silicone model 国際会議

    PIV 2013 Conference 2013年7月

  164. Correlation between Reynolds number and stenosis morphology in eccentric and concentric artery models 国際会議

    PIV 2013 Conference 2013年7月

  165. Application of optimization for design of intracranial stent with blood flow reduction as objective function 国際会議

    World Congress on Structural and Multidisciplinary Optimization 2013年5月

  166. Microbial Pore-Forming Protein Properties Depended on Lipid Environment 国際会議

    NIH-Tohoku UNiversity JSPS Symposium 2013年5月

  167. Friction of Medical Materials in Contact with PVA Hydrogel in Physiological Conditions 国際会議

    2013 annual ElyT workshop 2013年3月

  168. 血流低減を目的とした脳動脈瘤用ステントデザインの最適設計

    第62回理論応用力学講演会 2013年3月

  169. Study of the coil effect within an intracranial aneurysm 国際会議

    2013 annual ElyT workshop 2013年3月

  170. Evaluation for Drilling Properties of Bone Models 国際会議

    2013 annual ElyT workshop 2013年3月

  171. 親血管形状による動脈瘤の分類に対するステントストラットパターンの最適化に関する研究

    第25回 バイオエンジニアリング講演会 2013年1月

  172. 実形状動脈瘤を用いたステント形状最適化プログラム開発に関する研究

    安西 眸,Jean-Luc Falcone,Bastien Chopard,太田 信 2013年1月

  173. せん断応力を負荷した共存培養モデル内の血管平滑筋細胞の形質変化

    第25回 バイオエンジニアリング講演会 2013年1月

  174. 血管内ガイドワイヤシミュレータの研究

    第25回 バイオエンジニアリング講演会 2013年1月

  175. 医療デバイス周りの血流流体力学的見地からの血栓形成

    日本バイオマテリアル学会大会シンポジウム2012 2012年11月27日

  176. FLOW ANALYSIS OF STENOSIS AND ANEURYSM USING HYDROGEL FOR SOFT TISSUE SIMULATION 国際会議

    Syracuse University –Tohoku University Seminar 2012年11月8日

  177. 血管狭窄の硬さが血管拡張と狭窄下流部の血流に与える影響

    2012年日本脳神経血管内治療学会 2012年11月

  178. 骨組織を模擬したモデル材料におけるドリリング特性の評価

    日本バイオマテリアル学会大会シンポジウム2012 2012年11月

  179. Flow analysis of stenosis and aneurysm using hydrogel for comparison to computational simulation 国際会議

    MECHANICAL ENGINEERING and MATERIALS SCIENCE, Pittsburgh University 2012年10月11日

  180. Stent designs for efficient reduction of intra-aneurismal flow with various aneurysms 国際会議

    The 9th International Iterdisciplinary cerebrovascular Symposium (ICS12) 2012年10月

  181. Modeling Flow Diverter Stent using Porous Media 国際会議

    The 9th International Iterdisciplinary cerebrovascular Symposium (ICS12) 2012年10月

  182. Classification of Flow pattern in neck based on parent artery configuration and optimized stent implantation 国際会議

    The 9th International Iterdisciplinary cerebrovascular Symposium (ICS12) 2012年10月

  183. PVA-H 血管バイオモデルの冷却時間と厚さ制御に関する研究

    第23回 バイオフロンティア講演会 2012年10月

  184. Hemodynamics Effect of Y-Configuration Stenting on Basilar Tip Aneurysm 国際会議

    The 9th International Iterdisciplinary cerebrovascular Symposium (ICS12) 2012年10月

  185. Experimental Validation of FEA-Based Workflow to Simulate Flow Diverting Stent Deployment in Intracranial Aneurysms 国際会議

    The 9th International Iterdisciplinary cerebrovascular Symposium (ICS12) 2012年10月

  186. Efficacy of Mechanical Vibration on Radiofrequency Catheter Ablation 国際会議

    The 5th Asia-Pacific Heart Rhythm Society Scientific Session In Conjuction with 8th Asia-Pacific Atrial Fibrillation Symposium 2012年10月

  187. Localization of Disturbed Blood Flow in Intracranial Aneurysms : A Possible Association with Atherosclerosis 国際会議

    The 9th International Iterdisciplinary cerebrovascular Symposium (ICS12) 2012年10月

  188. Effect of the Aspect Ratio of Cerebral Aneurysms on Blood Flow Reduction after Optimized Stent Placement 国際会議

    Ninth International Conference on Flow Dynamics 2012年9月20日

  189. Electrophysiological Properties of Bacterial Membrane Channel Proteins Depending on Lipid Component and Bilayer Stability 国際会議

    Ninth International Conference on Flow Dynamics 2012年9月20日

  190. Ultrasound Radiation Force Driven B-Flow Twinkling Sign for Microcalcification Detection 国際会議

    The 12th International Symposium on Advanced Fluid Information and Transdisciplinary Fluid Integration (AFI/TFI-2012) 2012年9月20日

  191. Development of stent for cerebral aneurysm using fluid dynamics 国際会議

    2012 Beijing International Symposium on Biomechanics 2012年9月4日

  192. Comparison between Agarose gel and PVA-H Biomodels for Evaluation of Ablation Catheter 国際会議

    Ninth International Conference on Flow Dynamics 2012年9月

  193. Flow Analysis in Cerebral Aneurysm Model with Transparent Coils Placement 国際会議

    Ninth International Conference on Flow Dynamics 2012年9月

  194. Relationship between Fluid Shear Stress and the Phenotype Change of Smooth Muscle Cells in a Co-culture Model 国際会議

    Ninth International Conference on Flow Dynamics 2012年9月

  195. Size Validation of an Adrenal Vein Model for Development of an In Vitro Model with Realistic Geometrical Structure 国際会議

    Ninth International Conference on Flow Dynamics 2012年9月

  196. Friction and thermal Properties in Drilling of Bone Biomodels 国際会議

    Ninth International Conference on Flow Dynamics 2012年9月

  197. 脳動脈瘤に対するステントストラット位置の自動最適化に関する研究

    日本機械学会2012年度年次大会 2012年9月

  198. Channel Properties of Membrane Proteins on Lipid Bilayer 国際会議

    AFI/TFI-2012 2012年9月

  199. Characterization of Design of Stent Strut Positioning using LBM Method 国際会議

    AFI/TFI-2012 2012年9月

  200. Neumerical and Experimental Study of Flow in Stenosis models with Several Mechanical Properties 国際会議

    Ninth International Conference on Flow Dynamics 2012年9月

  201. ステントストラットパターンの最適化を持ちたステント開発に関する研究

    日本機械学会2012年度年次大会 2012年9月

  202. Measurement of Pressure Drop for Modeling Intracranial Flow Diverter Stent Using Porous Medium 国際会議

    Ninth International Conference on Flow Dynamics 2012年9月

  203. Tribology of Medical Materials on PVA-H Biomodel 国際会議

    AFI/TFI-2012 2012年9月

  204. Optimum Design of Flow Diverter Stent Associated with Arterial Geometries 国際会議

    Ninth International Conference on Flow Dynamics 2012年9月

  205. A Development of Lattice Boltzmann Model and Lumped Parameter Model Connection for Cardiovascular Multiscale Analysis 国際会議

    Ninth International Conference on Flow Dynamics 2012年9月

  206. Simulation of Hemodynamics in Artery with Aneurysm and Stenosis 国際会議

    Ninth International Conference on Flow Dynamics 2012年9月

  207. Oscillatory and Stagnant Flow in Intracranial Aneurysms: A Possible Association with Atherosclerosis 国際会議

    AFI/TFI-2012 2012年9月

  208. テーラーメイド医療ステントの開発から医療機器の国際標準規格まで

    第4回 流体科学におけるバイオ・医療に関する講演会 2012年7月26日

  209. Flow measurement using soft material for comparison of computational simulation 国際会議

    German Research School for Simulation Sciences GmbH 2012年7月12日

  210. PIV Measurement of Inflow through Cerebral Aneurysmal Neck of PVA-H Biomodel with Compliant Wall 国際会議

    8th European Solid Mechanics Conference 2012年7月

  211. The Design Characteristics Extracted From an Optimal Flow Diverter in an Ideal Side-wall Aneurysm Using Lattice Boltzmann Method 国際会議

    8th European Solid Mechanics Conference 2012年7月

  212. 軟組織内微細石灰化のB-Flow

    日本超音波医学会 2012年5月

  213. Characterization and image analysis of heteroheptameric structure on staphylococcal gamma-hemolysin transmembarne pore 国際会議

    Eighth International Conference on Flow Dynamics 2011年11月9日

  214. Effect of Aspect Ratio of Cerebral Aneurysm on flow reduction wuth stent 国際会議

    Eighth International Conference on Flow Dynamics 2011年11月9日

  215. Methodology of Evaluation for Medical Devices Using In-vitro/In-silico Biomodel 国際会議

    MHS,2011 International Symposium on Micro-NanoMechatronics and Human Science 2011年11月6日

  216. Control of wallthickness of blood vessel biomodel made of poly (vinyl alcohol) hydrogel by a three-dimentional rotating spin DIP-coating method 国際会議

    ASME INTERNATIONAL MECHANICAL ENGINEERING CONGRESS AND EXPOSITION 2011年11月

  217. Crystal Structure of the Octameric Pore of Staphylococcal γ-hemolysin 国際会議

    Eighth International Conference on Flow Dynamics 2011年11月

  218. Detection of Microcalcification in Soft Tissue Employing B-Flow 国際会議

    Eighth International Conference on Flow Dynamics 2011年11月

  219. Development of a methodology for adaptation of refractive index under controlling kinematic viscosity for PIV 国際会議

    ASME INTERNATIONAL MECHANICAL ENGINEERING CONGRESS AND EXPOSITION 2011年11月

  220. Effect of Initial Conditions of Stent Geometry on Optimized Design of Flow Diverters 国際会議

    Eighth International Conference on Flow Dynamics 2011年11月

  221. Friction Analysis of Biometal on PVA Biomodel 国際会議

    Eighth International Conference on Flow Dynamics 2011年11月

  222. Influence of Plaque Movement on Blood Flow and Blood Vessel around Stenosis Area 国際会議

    Eighth International Conference on Flow Dynamics 2011年11月

  223. Involvement of ERK in Morphological Response of Endothelial Cells to Spatial Gradient of Shear Stress 国際会議

    Eighth International Conference on Flow Dynamics 2011年11月

  224. Local Blood Flow Instability and Oscillatory Shear in Intracranial Aneurysms 国際会議

    Eighth International Conference on Flow Dynamics 2011年11月

  225. Observation of Behavior of Injection for Composite Material using Micro-CT 国際会議

    Eighth International Conference on Flow Dynamics 2011年11月

  226. PIV Mesurement of Steady Flow in PVA Model with Compliant Wall as Cerebral Aneurysm 国際会議

    Eighth International Conference on Flow Dynamics 2011年11月

  227. 微細石灰化を含んだ乳房組織を模擬したPVA phantomの実験的研究

    第49回人工臓器学会 2011年11月

  228. Friction of Medical Metallic Alloys on Soft Tissue Biomodel 国際会議

    International Tribology Conference 2011年10月

  229. PVAバイオモデルを用いたアブレーションカテーテルの温度分布の評価に関する研究

    第22回バイオフロンティア講演会 2011年10月

  230. Assessment of stent using in vitro/-silico biomodelling 国際会議

    8th International Interdisciplinary cerebrovascular Symposium and 11th Oriental Conference of Interventional Neuroradiology and 6th East Asian Conference of Neurointervention 2011年9月8日

  231. Analysis of cell adhesion on PVA-H for developing vessel bio-model with dynamical and biological responses 国際会議

    24th European Conference on Biomaterials The Annual Conference of the European Society for Biomaterials 2011年9月

  232. Development ofthe design of flow diverters using automated optimization based on lattice boltzmann method 国際会議

    8th International Interdisciplinary cerebrovascular Symposium and 11th Oriental Conference of Interventional Neuroradiology and 6th East Asian Conference of Neurointervention 2011年9月

  233. Friction Behavior of Medical Metallic Alloys against Biomimetic Poly (vinyl alchol) Hydrogel 国際会議

    24th European Conference on Biomaterials The Annual Conference of the European Society for Biomaterials 2011年9月

  234. Influence of plaque stiffness on hemodynamics based on experimental studies with vitro PVA biomodel 国際会議

    8th International Interdisciplinary cerebrovascular Symposium and 11th Oriental Conference of Interventional Neuroradiology and 6th East Asian Conference of Neurointervention 2011年9月

  235. Optimization of Stent Strut Pattern for Cerebral Aneurysm 国際会議

    8th International Interdisciplinary cerebrovascular Symposium and 11th Oriental Conference of Interventional Neuroradiology and 6th East Asian Conference of Neurointervention 2011年9月

  236. Study on Effect of Blood Flow Reducing by Stent 国際会議

    8th International Interdisciplinary cerebrovascular Symposium and 11th Oriental Conference of Interventional Neuroradiology and 6th East Asian Conference of Neurointervention 2011年9月

  237. PIV MEASURED HEMODYNAMIC STUDY WITH SEVERAL STENTS IN A CEREBRAL ANEURYSM MODEL FOR NEW STENT DESIGN 国際会議

    AJK2011 2011年7月

  238. 未破裂脳動脈瘤の破裂リスクに関する3次元可視化システムを用いたCFD解析の試み

    第34回日本バイオレオロジー学会年会, 2011年6月

  239. 脳動脈瘤用ステントデザインの設計方法

    京都大学再生医科学研究所セミナー 2011年4月21日

  240. フローダイバーターの脳動脈瘤ステント設計

    SMAシンポジウム2010 2010年11月26日

  241. 多機能なカテーテル評価のためのPVA-Hモデルを用いた循環路システムの開発

    日本人工臓器学会, 2010年11月19日

  242. 壁厚制御されたPVA-H血管バイオモデルの開発

    日本人工臓器学会 2010年11月19日

  243. Development of in vitro system for intracranial stent evaluation 国際会議

    Swiss/Japan International Seminar on Medical Emgineering Based on Vessel Biology 2010年11月15日

  244. Development of vessel biomodel with dynamic and biological properties by cell attachment on PVA-H 国際会議

    Swiss/Japan International Seminar on Medical Emgineering Based on Vessel Biology 2010年11月15日

  245. 欧州研究枠組みを利用して -FP6@neuroIST project-

    J-Bilat 第5回セミナー 2010年11月11日

  246. Analyzing Blood Flow in Bifurcated Artery with Cerebral Aneurysm Using Two Stents 国際会議

    Seventh international Conference on Flow Dynamics 2010年11月

  247. Characterization of γ-Hemolysin on Liposome 国際会議

    AFI/TFI 2010 2010年11月

  248. Development of Cell-Matrix Adhesion Techniques on Transparent PVA-H for Vessel Biomodeling 国際会議

    Seventh international Conference on Flow Dynamics 2010年11月

  249. Development of PVA-H stenosis model 国際会議

    Swiss/Japan International Seminar on Medical Emgineering Based on Vessel Biology 2010年11月

  250. Development of PVA-H Stenosis Model for PIV Measurement 国際会議

    Seventh international Conference on Flow Dynamics 2010年11月

  251. Development of Stent for Cerebral Aneurysm based on Optimization 国際会議

    AFI/TFI 2010 2010年11月

  252. Friction Properties of PVA-H for Biomodel and Steel Ball for Medical Devices 国際会議

    AFI/TFI 2010 2010年11月

  253. Mechanical Properties and Microstructure of Injected Biomodeling 国際会議

    Seventh international Conference on Flow Dynamics 2010年11月

  254. PIV measured hemodynamic study with several stents in a cerebral aneurysm model 国際会議

    Swiss/Japan International Seminar on Medical Emgineering Based on Vessel Biology 2010年11月

  255. Tribological study on metallic alloy used for stent against blood vessel biomodel 国際会議

    Swiss/Japan International Seminar on Medical Emgineering Based on Vessel Biology 2010年11月

  256. 歯科インプラント手術トレーニング用骨バイオモデリングの力学的特性に関する研究

    日本人工臓器学会 2010年11月

  257. 透明Poly (vinyl alcohol) Hydrogel バイオモデル上への血管細胞の効果的付着技術の開発

    日本バイオマテリアル学会2010 2010年11月

  258. Cell adhesion on PVA-H for development of biomodel with biological response 国際会議

    International Mini Symposium for Biomechanics and Intracranial Stent 2010年10月20日

  259. 4次元CTによる新しい血量速度計測用の開発と基礎的検討

    日本放射線技術学会 2010年9月22日

  260. State-of-the-Art CT Imaging Techniques for Cerebrovascular Disease

    画像処理研究会 2010年9月22日

  261. Cell Adherence on Transparent PVA-H Coated with Extracellular Matrix 国際会議

    23th European Conference on Biomaterials, 2010年9月12日

  262. 血管バイオモデル内流れのPIV計測のための疑似血液流体開発

    日本流体力学学会年会 2010 2010年9月10日

  263. Computational Design of Intracranial Stent Using 3D Visualization System 国際会議

    Live International Neuroradiology Conference (Inconjunction with the 7th ICS) 2010年9月

  264. Flequency-Dependence of Blood Vessel Biomodel Made of Poly(vinyl alcohol) Hydrogel 国際会議

    23th European Conference on Biomaterials 2010年9月

  265. Subunit arrangement analysis of staphylococcal γ-hemolysin heteroheptameric transmembrance pore

    生物物理 supplement2 2010年9月

  266. Towards the Simulations of Endovascular Treatment for Cerebral Aneurysm 国際会議

    The 6th Beijing International Symposium on biomechanics 2010年8月26日

  267. Development of Blood-Mimicking Fluid with Ajusted Refractive Index and Kinematic Viscosity for Applying to Particle Image Velometry 国際会議

    6th World Congress of Biomechanics 2010年8月3日

  268. Simulations of Endovascular Treatment for Cerebral Aneurysm 国際会議

    6th World Congress of Biomechanics 2010年8月2日

  269. Analysis of Mechanical Properties and Microstructure for Development of Bone-Biomodeling 国際会議

    6th World Congress of Biomechanics 2010年8月

  270. Development of Fundamental Techniques of Cell Adhesion on Transparent PVA-H for Biomodeling 国際会議

    6th World Congress of Biomechanics 2010年8月

  271. Modification of transparent poly(vinyl alcohol) hydrogel with extracellular matrix promotes effective cell adhesion for biomodeling 国際会議

    International Conference on Cellular & Molecular Bioengineering 2010年8月

  272. Molecular Architecture Analysis of Staphylococcal hemolysin Heteroheptameric Transmembrance Pore : Construction of Three-Dimenational Structure with Subunit Arrangement Mismatch Based on High-resolution Electron Microscopic Image 国際会議

    6th World Congress of Biomechanics, 2010年8月

  273. Analysis of Three-dimetional Structure and Subunit Mismatch in Staphylococcal γ-Hemolysin Heterohepameric Transmembrance Pore 国際会議

    Microscopy and Microanalysis 2010年8月1日

  274. 脳動脈用ステントにおける流体力学的理論解析の試み

    第16回日本血管内治療学会総会 2010年7月23日

  275. 脳動脈用ブレブ部分の流れの数値解析とその血管撮影による検証

    第16回日本血管内治療学会総会 2010年7月23日

  276. Biomodel for Development of Intracranial Stent 国際会議

    SIRIC International Symposium 2010 2010年7月2日

  277. Computational Simulation of Intracranial Stent using 3D visualization system 国際会議

    SIRIC International Symposium 2010 2010年7月2日

  278. 血管バイオモデルを用いたPIVによる瘤内コイル周りの血流解析

    第1回国際バイオレオロジーシンポジウム,第33回日本バイオレオロジー学会年会 2010年6月3日

  279. ブドウ球菌の2成分性毒素γヘモリジン膜孔複合体における分子配置解析と立体構造予測

    日本顕微鏡学会 第66回学術講演会 2010年5月24日

  280. Development of Bone-Biomodeling for Surgical Simulations 国際会議

    2010 Annual ELyt Workshop 2010年3月

  281. Development of Stent Designing for Cerebral Aneurysm 国際会議

    2010 Annual ELyt Workshop 2010年3月

  282. In-virto blood flow circulation system using PVA model for evaluating medical devices 国際会議

    2010 Annual ELyt Workshop 2010年3月

  283. Present Study of Poly(vinyl alcohol) Hydrogel Based Biomodel for Endovascular Treatment 国際会議

    2010 Annual ELyt Workshop 2010年3月

  284. PVAバイオモデルの壁厚測定

    日本機械学会東北支部第45期総会・講演会 2010年3月

  285. Tribology of PVA biomodel (Biocath project) 国際会議

    2010 Annual ELyt Workshop 2010年3月

  286. ブドウ球菌の2成分性毒素γヘモリジンが形成するヘテロヘプタマ−膜孔複合体の立体構築とサブユニット間配置の定量的解析

    日本農芸化学会2010年度(平成22年度)大会 2010年3月

  287. Rheology-Fluid Dynamics of Blood Flow Modelling and Simulation-Basics of Fluid 国際会議

    The Australasian College of Phlebology, 13th Annual Scientifc Meeting & Workshops 2010年2月6日

  288. FROTTEMENT LUBRIFIE DU CONTACT PVA / ACIER 国際会議

    le comitee; scientifique de JIFT 2010 2010年2月

  289. Jet-Fluid Effects on the Stented-Flow Structure in the Cavity of Cerebral Aneurysm 国際会議

    Biophysical Society, 54th annual meeting 2010年2月

  290. Development of stent for Cerebral Aneurysm 国際会議

    the Ninth International Symposium on Advanced Fluid Information and Transdisciplinary fluind Integration(ATI/TFI 2009), 2009年11月

  291. Experimental Study on a Catheter Movement for Evaluating Catheter Designs Using an In-Vitro Tracking System 国際会議

    Sixth International Conference on Flow Dynamics(ICFD), 2009年11月

  292. コイルを留置させた脳動脈瘤モデルでの血流の定量的測定法の開発

    第25回日本脳神経血管内治療学総会 2009年11月

  293. ポリビニルアルコールハイドロゲルを用いた3次元血管モデルの構築と力学的特性の計測

    第31回日本バイオマテリアル学会大会 2009年11月

  294. 脳動脈瘤コイル塞栓後の血流変化の計算機流体力学による評価

    第25回日本脳神経血管内治療学総会 2009年11月

  295. Analysis of Drilling Bone Biomodeling 国際会議

    International Bone-Tissue-Engineering Congress 2009年10月

  296. Three-dimensional structure analysis of staphylococcal γ-hemolysin heteroheptameric transmembrance pore complex

    日本生物物理学会第47回年会講演 2009年10月

  297. 3次元可視化システムを用いた血流数値解析の可視化

    日本機械学会2009年度年次大会 2009年9月14日

  298. 3D Observation of Expansion of Stent and Elastic Recoil using Micro-CT 国際会議

    World Congress on Medical Physics and Biomedical Engineering 2009年9月

  299. Catheter and guidewire simulator for intravascular surgery (Comparison between simulation results and medical images) 国際会議

    The World Congress on Medical Physics and Biomedical Engineering 2009 2009年9月

  300. Development of Particle Image Velocimetry System for intra-aneurysmal flow in arterial biomodel made of Poly (vinyl alcohol) hydrogel 国際会議

    Third Switzerland-Japan workshop on Biomechanics 2009(SLB 2009), 2009年9月

  301. Friction properties of PVA-H / steel ball contract 国際会議

    World Tribology Congress 2009 2009年9月

  302. Molecular architecture analysis of Staphylococcal γ-hemolysin heteroheptameric transmembrane pore complex 国際会議

    Third Switzerland-Japan workshop on Biomechanics 2009(SLB 2009), 2009年9月

  303. Poly (vinyl alcohol)動脈瘤バイオモデル内流れのParticle Image velocimetry 計測における作動流体開発

    計測自動制御学会東北支部45周年記念学術講演会 2009年9月

  304. Poly(vinyl alcohol) Hydrogel with Controlled Wall Thickness for Blood Vessel Biomodelilng 国際会議

    Third Switzerland-Japan workshop on Biomechanics 2009(SLB 2009), 2009年9月

  305. コイルが留置された脳動脈瘤モデル内の流れに関する研究

    日本機械学会2009年度年次大会 2009年9月

  306. ブドウ球菌の2成分性毒素γヘモリジンが形成するヘテロヘプタマー膜孔複合体の立体構造解析

    第54回日本ブドウ球菌研究会 2009年9月

  307. 生体材料を活用した管内MR流体流動の動的応答と高機能化

    日本混相流学会年会講演会2009 2009年8月7日

  308. Evaluation of Poly (vinyl alcohol) Hydrogel Biomodeling by Using Ultrasound 国際会議

    International Intracranial Stent Meeting 2009 2009年8月4日

  309. 3D Visualization of numerical simulation of blood flow on intracranial stent 国際会議

    International Intracranial Stent Meeting 2009 2009年8月

  310. A parametric model for side wall and bifurcation cerebral aneurysms 国際会議

    International Intracranial Stent Meeting 2009 2009年8月

  311. Computational Fluid Dynamics of Carotid Arteries after Carotid Endarterectomy or Carotid Artery Stenting based on Postoperative Patient-specific Data 国際会議

    International Intracranial Stent Meeting 2009 2009年8月

  312. Development of Bone Biomodeling for drilling 国際会議

    International Intracranial Stent Meeting 2009 2009年8月

  313. Experimental Study on a Catheter Movement for evaluating Catheter Designs 国際会議

    International Intracranial Stent Meeting 2009 2009年8月

  314. Improvement of Dynamic Four-dimensional CT Angiography (DFA) and apply to the Computational Fluid Dynamics 国際会議

    International Intracranial Stent Meeting 2009 2009年8月

  315. Measurement of Flow Speed of In Vitro Aneurysm Models with Coils Using Particle Image Velocimetry (PIV) 国際会議

    International Intracranial Stent Meeting 2009 2009年8月

  316. Numerical Analysis on Characteristic Effects of Stent in Cerebral Vessels 国際会議

    International Intracranial Stent Meeting 2009 2009年8月

  317. Optical properties measurement of Poly (vinyl alcohol) hydrogel biomodel for applying Particle Image Velocimetry 国際会議

    International Intracranial Stent Meeting 2009 2009年8月

  318. 黄色ブドウ球菌の2成分血球崩壊毒素γヘモリジンが形成する膜孔複合体の立体構造解析

    日本顕微鏡学会第65回学術講演会 2009年5月

  319. Study on the Development of Blood Vessel Biomodeling with Realistic Mechanical Properties by Using Poly (vinyl alcohol) Hydrogel 国際会議

    4th Asian Pacific Conference on Biomechanics 2009年4月17日

  320. Measurement of Dynamic Viscoelasticities and Sensory Evaluations of Poly (Vinyl Alcohol) Hydrogel for Development of Oral Mucosa Model 国際会議

    4th Asian pacific Conference on Biomechanics 2009年4月15日

  321. Study on a Catheter Movement with Poly (vinyl alcohol) Hydrogel for the Development of an In-Vitro Tracking System 国際会議

    Fourth Asian Pacific Conference on Biomechanics 2009年4月15日

  322. 血管内カテーテル/ガイドワイヤシミュレータ(計算結果と医用画像との比較)

    第48回日本生体医工学会大会 2009年4月

  323. Blood flow in cerebral aneurysm; Computational simulations and biomodels 国際会議

    ヨンセイ大学 2009年3月30日

  324. Blood flow in cerebral aneurysm; Computational simulations and biomodels 国際会議

    Special lecture in Yonsei University 2009年3月30日

  325. Computational Studies on Characteristic fluid behavior in the stented Cerebral Aneurysm 国際会議

    American Physical Society March meeting 2009年3月18日

  326. 医療デバイス開発のための要素技術開発-バイオモデルとシミュレーション-

    低侵襲医療機器実現化フォーラム「脳外科領域の血管内治療」 2009年3月12日

  327. Tribological behavior of PVA hydrogel for biological model of arteries 国際会議

    International Conference on Bioengineering & Biomaterials 2009年3月

  328. The Effect of Computational Simulation on EndovascularTreatments of Cerebral Aneurysm 国際会議

    the Third International Symposium on Biomechanics,Human Function and Information Science 2009年2月21日

  329. Study of Searching Method for Position of Stent Strut to Decrease Blood flow in Cerebral Aneurysm 国際会議

    the Third International Symposium on Biomechanics,Human Function and Information Science 2009年2月20日

  330. Evaluation of After CAS Operation by Flow and Wall Shear Stress Using CFD Simulation 国際会議

    the Third International Symposium on Biomechanics,Human Function and Information Science 2009年2月

  331. The Effect of Computational Simulation on EndovascularTreatments of Cerebral Aneurysm 国際会議

    the Third International Symposium on Biomechanics,Human Function and Information Science 2009年2月

  332. Poly(Vinyl Alcohol)Hydrogelを用いた口腔粘膜モデルの開発

    第21回バイオエンジニアリング講演会 2009年1月

  333. ステントストラット配置が脳動脈瘤モデル内の流れに与える影響

    第21回バイオエンジニアリング講演会 2009年1月

  334. 血管バイオモデリング開発を目的としたポリビニルアルコールハイドロゲルの力学的特性評価

    第21回バイオエンジニアリング講演会 2009年1月

  335. 脳動脈瘤内の血流減少における最適な箇所の探索

    第21回バイオエンジニアリング講演会 2009年1月

  336. Development for Catheter Motion Tracking System Using Poly(vinyl alcohol) Hydro-gel Biomodel 国際会議

    The Eighth International Symposium on Advanced Fluid Information and Transdiciplinary Fluid Integration 2008年12月

  337. Development of PVA-H as a biomodel 国際会議

    ELyT Lab Workshop 2008年12月

  338. Evaluation of Compliance of Poly(Vinyl Alcohol) Hydrogel for Development of Arterial Biomodeling 国際会議

    13th International Conference on Biomedical Engineering 2008年12月

  339. 64列MDCTのCine Dynamis Scan による拍動嚢状動脈瘤モデルの壁運動描出

    第24回日本脳神経血管内治療学会総会 2008年11月

  340. Introduction of JSPS Core to Core Program: Establishment of International Research Consortium for Advanced Biommedical Engineering in Interface Flow Dynamics for Blood Flows, Blood Vessels, and Biomaterials 国際会議

    Fifth International Conference on Flow Dynamics 2008年11月

  341. The Effect of Neck Shape on Flow Pattern in Cerebral Aneurysm using Computational Fluid Simulation with Idealized Models 国際会議

    Fifth International Conference on Flow Dynamics 2008年11月

  342. 脳血管内カテーテル・ガイドワイヤシュミレータ

    第24回日本脳神経血管内治療学会総会 2008年11月

  343. PVAハイドロゲルとメッシュ材料を用いた異方性血管モデルの制作

    第19回バイオフロンティア講演会 2008年9月

  344. 脈診用脈波計測装置、物性と形状を兼ね備えたバイオモデル

    東北大学イノベーションフェア 2008年9月

  345. 各ステントストラットが瘤内の血行動態へ及ぼす影響

    機械学会 2008年度年次大会 2008年8月

  346. 脳動脈ステントの動向

    第6回 「医療・福祉・環境における形状記憶合金の高機能化および応用に関する分科会 2008年8月

  347. 脳動脈瘤用ステントによる血流制御と治療アセスメント

    第33回CG・可視化研究会 2008年8月

  348. Heat Diffusion Characteristics of Magnetite Nanoparticles Dispersed Hydro-gel in AC Magnetic Field 国際会議

    Intrenational Symposium on Nanotoxicology Assessment and Biomedical,Environmental Application of Fine Particles and Nanotubes 2008年6月

  349. Heat Diffusion Characteristics of Magnetite Nanoparticles Dispersed Hydro-gel in AC Magnetic Field 国際会議

    The 7th International Conference on the Scientific and Clinical Applications of Magnetic Carriers 2008年5月

  350. Observation of Motion of Blood Vessel Biomodeling Made of Poly (Vinyl Alcohol) Gel with Ultrasound 国際会議

    The 5th International Intracranial Stent Symposium 2008年5月

  351. Obsevation of Three-Dimentional Elastic Recoil of Balloon-Expandable Stent 国際会議

    The 5th International Intracranial Stent Symposium 2008年5月

  352. Sensory Evaluation of Poly (Vinyl Alcohol) Gel for Surgical Operation of Soft Tissue 国際会議

    The 5th International Intracranial Stent Symposium 2008年5月

  353. Several Stent Struts Increase Blood Flow Speed in Cerebral Aneurysm 国際会議

    The 5th International Intracranial Stent Symposium 2008年5月

  354. The Effect of Neck Shape of Aneurysm on Inflow Zone at the Neck Using Computational Fluid Simulation 国際会議

    The 5th International Intracranial Stent Symposium 2008年5月

  355. 64列MDCTのCine Dynamic Scanによる拍動嚢状動脈瘤モデルの壁運動描出

    日本放射線技術学会第64回総会学術大会 2008年4月

  356. The Effect of Boundary Condition with Ultrasound Measurement on Blood Flow Simulation in Carotid Artery 国際会議

    the 2nd Interantional Symposium on Biomechanics, Healthcare and Information Science 2008年3月15日

  357. Poly (vinyl alcohol) gelを用いた口腔粘膜モデルの開発と一対比較法による物性評価

    日本機械学会東北支部第43期総会・講演会 2008年3月

  358. Three Dimensional Behavior of Balloon-Expandable Stent using Micro-CT 国際会議

    the 2nd Interantional Symposium on Biomechanics, Healthcare and Information Science 2008年3月

  359. 脳動脈瘤ネックにおけるステントストラットパターンと瘤内の血行動態に関する研究

    第20回バイオエンジニアリング講演会 2008年1月

  360. バイオモデリングと脳動脈瘤用ステント

    日本生体医工学会 専門別研究会 第120回研究会 2007年11月12日

  361. Effest of Stenting Rotational Positions on Hemodynamics in a Cerebral Aneurysm 国際会議

    AMERICAN SOCIETY OF NEURORADIOLOGY 2007年6月

    詳細を見る 詳細を閉じる

    Nakayama,T. Ohta,M. Rufenachat,D.A. Takahashi,A.

  362. Cinematic Angiography for Assesments of blood Flow in Cerebral Aneurysm with Stents 国際会議

    AMERICAN SOCIETY OF NEURORADIOLOGY 2007年6月

    詳細を見る 詳細を閉じる

    Ohta,M. Fujimura,N. Augsburger,L. Barath,K. Yilmaz,H Abdo,G. Ruefenachat,D.A.

  363. The Effect to Hemodynamics of an Intracranial Aneurysm by a Difference of Stent Struct Design 国際会議

    The 4th International Intracranial Stent Meeting 2007年4月

    詳細を見る 詳細を閉じる

    Toshio Nakayama, Makoto Ohta, Daniel A.Rufenachat Akira Takahashi

  364. Optimisation of Stents for Aneurysm 国際会議

    The 4th International Intracranial Stent Meeting 2007年4月

    詳細を見る 詳細を閉じる

    K. Srinivas, M Ohta, T. Nakayama, S. Obayashi T. Yamaguchi

  365. Studies on Funstional Biomodeling of Cerebral Artery with Mechanical Properties using Poly (vinyl alcohole) Hydro-gel 国際会議

    The 4th International Intracranial Stent Meeting 2007年4月

    詳細を見る 詳細を閉じる

    Hiroyuki KOSUKEGAWA, Keisuke MAMADA, Lei LIU, Kanju KUROKI, Toshiyuki HAYASE, Makoto OHTA

  366. Quantification of Flow in aneurysm for Development of Intracranial Stent 国際会議

    The 4th International Intracranial Stent Meeting 2007年4月

  367. From Micro-CT to Numerical Simulation:The Effect of Intracranial Stent on Hemodynamics in Cerebral Aneurysm 国際会議

    The Third B-J-K symposium on Biomechanics 2007年3月

    詳細を見る 詳細を閉じる

    Toshio Nakayama, Makoto Ohta, Daniel A. Rufenachat, Akira Takahashi

  368. In-vitro model of artery based on Poly vinyl alcohol (PVA) hydrogel (PVA-H) with low friction 国際会議

    The 4th LYON-TOHOKU ENGINEERING & SCIENCE FORUM 2007年2月

  369. Bio-tribology of a catheter/biomodel vessel contact 国際会議

    The 4th LYON-TOHOKU ENGINEERING & SCIENCE FORUM 2007年2月

  370. The Effect of Stenting with Difference Positions on Hemodynamics in a Cerebral Aneurysm 国際会議

    The 9th International Symposium on Future Medical Engineering Based on Bio-nanotechnology 2007年1月

    詳細を見る 詳細を閉じる

    Toshio Nakayama, Makoto Ohta, Daniel A.Rufenachat Akira Takahashi

  371. Development of fundamental technologies with use of in-vitro and in-silico models for endovascular treatments 国際会議

    kick-off meeting of @neurIST 2006年2月8日

  372. Development of fundamental technologies with use of in-vitro and in-silico models for endovascular treatments 国際会議

    Daniel A, RÜFENACHT, Pedro LYLYK, Toshiyuki HAYASE, Akira TAKAHASHI

    Fifth International Symposium on Advanced Fluid Information (AFI-2005) —IFS-JAXA Joint Symposium— 2005年12月8日

  373. Subtracted Vortex Centres Path line method with Cinematic Angiography for evaluating flow in stented cerebral aneurysm 国際会議

    Naoko Fujimura, Krisztina Barath, Stephan G. Wetzel, Luca Augsburger, Edouard Fonck, Hasan Yilmaz, German Abdo, Karl-Olof Lovblad, Nikos Stergiopulos, Daniel A. Rüfenach

    The 2nd Japan-Switzerland workshop on biomechanics 2005年9月12日

  374. 血管モデルと血流ダイナミクス

    IVR学会夏期学術セミナー 2005年7月30日

  375. 医療における工学の関わり~脳動脈瘤の血管内治療を例に~

    宮城県脳ドック研究会 2005年7月26日

  376. Computer simulation, In-Vitro simulation and Patient data 国際会議

    Intra Cranial Stent Meeting 2005 2005年3月16日

  377. 16)Rheological changes after stenting of a cerebral aneurysm: a finite element modeling approach 国際会議

    M. Ohta, S. Wetzel, P. Dantan, H. Yilmaz, K. O. Loevblad, P. Flaud, D. A. Rüfenacht

    Cardiovascular and Interventional Radiological Society of Europe 2004年9月

  378. Experience in In-vitro Modeling of Intracranial Aneurysms 国際会議

    OHTA M, HANDA A, AUGSBURGER L, WETZEL S, ABDO G, IWATA H, TSUTSUMI S, FASEL J, RÜFENACHT DA

    International Workshop on Flow and Motion 2004年7月

  379. 14)How to validate computer flow simulation results? – On the use of patient data based vascular model production and in-vitro model flow analysis. 国際会議

    OHTA Makoto, AUGSBURGER Luca, FUJIMURA Naoko, WETZEL Stephan, IWATA Hiroo, TSUTSUMI Sadami, RÜFENACHT Daniel A

    4th international symposium on future medical engineering 2004年6月

  380. 13)Hemodynamic Studies of Coiling in Cerebral Aneurysm by Using Particle Image Velocemetry (PIV) Method 国際会議

    Makoto OHTA, Vincent GARITEY, Olivier LEVRIER, Régis RIEU, Francis CASSOT, Daniel A, RUEFENACHT

    42nd American Society of Neuroradiology Annual meeting 2004年5月

  381. 超音波血管撮像用PVA-Hモデルの開発

    M. S. S. Hashuro, Simon Tupin, 井上 浩介, 早瀬 敏幸, 太田 信

    超音波血管撮像用PVA-Hモデルの開発

︎全件表示 ︎最初の5件までを表示

産業財産権 6

  1. マウスガード及びマウスガード用乾燥ゲルの製造方法

    堤 定美, 太田 信, 玄 丞烋, 岡野 仁夫

    産業財産権の種類: 特許権

  2. マウスガードとその製造方法

    堤 定美, 太田 信, 玄 丞烋, 岡野 仁夫

    産業財産権の種類: 特許権

  3. PCT出願 標準血管生成装置、血管評価装置、標準血管生成プログラム、血管評価プログラム、標準血管生成方法及び血管評価方法

    産業財産権の種類: 特許権

  4. 多機能体内留置ステント

    山家智之, 太田信, 松木英敏, 佐藤文博, 堀義生, 白石泰之, 前田剛, 関根一光, 三浦英和, 角張泰之, 荒井真輔

    産業財産権の種類: 特許権

  5. 骨模型

    太田信, 柴田幸彦, 及川直人, 片倉裕司

    産業財産権の種類: 特許権

  6. 生体模型のための粘膜材

    太田信, 柴田幸彦, 及川直人, 片倉裕司

    産業財産権の種類: 特許権

︎全件表示 ︎最初の5件までを表示

共同研究・競争的資金等の研究課題 26

  1. 合併症を再現できる内視鏡手技シミュレータを展開し、有効な学習プログラムを構築する

    菅野 武, 太田 信, 荒田 悠太郎

    2022年4月1日 ~ 2025年3月31日

  2. 患者固有の脳動脈瘤内血流に対する弾性壁の効果

    山口 隆平, 太田 信, 田中 学, 安西 眸

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research

    研究種目:Grant-in-Aid for Scientific Research (C)

    研究機関:Tohoku University

    2022年4月1日 ~ 2025年3月31日

  3. 慢性関節炎の微小血管塞栓術に関する基礎実験

    小黒 草太, 高瀬 圭, 石幡 浩志, 権田 幸祐, 太田 信, 中村 保宏, 大田 英揮, 佐藤 友美, 鎌田 裕基

    2022年4月1日 ~ 2025年3月31日

  4. 数理的血管分岐パターン分類と血管走行標準化による動脈瘤発生予測モデルの確立

    森 菜緒子, 麦倉 俊司, 太田 信, 安西 眸, 北村 洸

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research

    研究種目:Grant-in-Aid for Scientific Research (C)

    研究機関:Tohoku University

    2022年4月1日 ~ 2025年3月31日

  5. 超弾性NiTi合金への陽極酸化によるTiO2皮膜形成―機序の解明と表面機能の評価

    大津 直史, 太田 信, 坂入 正敏

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

    研究種目:Grant-in-Aid for Scientific Research (B)

    研究機関:Kitami Institute of Technology

    2021年4月1日 ~ 2024年3月31日

  6. MRA血管走行・壁ストレス標準モデルを用いた脳卒中リスクの可視化

    麦倉 俊司, 太田 信, 安西 眸, 森 菜緒子

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)

    研究種目:Grant-in-Aid for Scientific Research (C)

    研究機関:Tohoku University

    2021年4月1日 ~ 2024年3月31日

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    脳卒中はリスクファクターとして性別,人種,遺伝子,高血圧,糖尿病,脂質異常,加齢があげられている.MRIはイベントが発症してから出血や梗塞の範囲,閉塞血管を評価し,治療方針や予後を決定するために用いられているが,イベント発症前のリスク評価は行われていない.我々は,MR angiography(MRA)をMontreal Neurological Institute (MNI)templateにより標準座標へ変換することにより血管走行位置座標を標準化し,さらに血管の中心点を抽出し分岐点を同定することにより,標準座標上の血管走行を抽出する技術を開発した.本研究の目的は,脳卒中リスクをMRA画像により可視化することである.具体的には,1) 大規模地域住民コホートを用い,各年代の血管走行・壁ストレス標準モデルを作成する.2)モデルからの逸脱に関連する遺伝子,性別,年齢,生活習慣などの要因を明らかにし,脳卒中リスクファクターを定量化する.3)ラット高血圧モデルにおいて血管走行・壁ストレス変化を確認する.我々は,脳卒中発症前リスクを可視化することを目的に,医療技術,大規模コホート研究,工学技術の3つを融合させることにより,血管走行・壁ストレス標準モデルを作成する.本技術により,血管走行・壁ストレス標準モデルを作成し,脳卒中リスクを可視化し,更にラット高血圧モデルにおいてMRAを撮像し,確認する.

  7. アイトラッキングによるカテーテル術者の目線解析と訓練に役立つ目線パターンの解明

    庄島 正明, 小泉 聡, 太田 信, 岡本 吉弘

    2021年4月1日 ~ 2024年3月31日

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    実臨床データの収集と解析:脳血管内治療を実施する術者の経験と相関する目線パラメータを明らかにするために、実臨床データの収集を行った。3年間で30症例のデータ取得と解析を予定しているが、2021年度は、9件の血管内治療中の目線データの取得をおこなった。埼玉医科大学で7件、帝京大学で2件のデータ取得を行った。血管内治療手技の内訳は、脳動脈瘤コイル塞栓術が2件、フローダイバーター留置術が3件、脳動静脈奇形塞栓術が2件、脳腫瘍栄養血管塞栓術が1件、慢性硬膜下血腫に対する血管塞栓術が1件だった。 非臨床実験:経験レベルの低い術者の目線データを収集・解析するために、血管モデルを作成し、模擬手術を実施中の術者の目線データを3年間で30被検者より収集することを予定している。2021年度は血管モデルの作成に取りかかった。当初は、半年かけて完成させる予定だったが、研究場所の変更と時期が重なってしまい、実施が遅れた。2021年度は血管モデルのCADモデルを作成し、それをプリントしてくれる業者(Bluepractice社)と打ち合わせをおこなった。いまだ血管モデルの細部の微調整を継続している。

  8. 血液透析シャント狭窄を防ぐ埋込型デバイスの研究開発

    梶山 愛, 木下 知, 鈴木 智之, 太田 信, 安西 眸, 片平 晋太郎

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)

    研究種目:Grant-in-Aid for Scientific Research (C)

    研究機関:Tohoku University

    2021年4月1日 ~ 2024年3月31日

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    本年度の研究目標は、慢性期動物実験(雌ビーグル犬1匹)を以下の①②③④の手順で実施し、デバイスの基礎的な安全性及び有効性の評価を行うことで、デバイスのコンセプト検証を行うことである。 ①デバイス製作(担当:梶山):現状のデバイスをもとにして透析専門医(弘前大学病院泌尿器科)の協力を得ながら、装着時ユーザビリティを考慮した設計を行った。材料は熱硬化性ポリウレタンエラストマーを使用し、(株)KobeWaposにて製造を行った。 ②シャント造設手術:東北大学医学部附属動物実験施設にて、同大学病院心臓血管外科とともに、ビーグル犬の左大腿動静脈には従来の鋭角吻合形状シャントを、右大腿動静脈にはデバイスを装着した鈍角吻合形状シャントを作製した。この時、デバイス留置による血管および周囲組織の破損は確認されなかったため、留置時の安全性には問題ないと分かった。 ③造影CT撮像によるWall shear stress値算出:シャント作製直後および作製2週間後において、左右シャント部分の造影CT撮像を行う(東北大学医学部保健学科協力)ことで、シャントの3次元データを取得し、流体シミュレーションソフトAnsysを用いてシャント吻合部におけるwall shear stres値を算出した。その結果、従来シャントのみにおいてシャント吻合部で異常なwall shear stressが発生しており、シャント狭窄が最も多く発生する箇所と一致した。 ④シャント組織の摘出・病理観察:シャント造設後2週間後安楽死処置を行った上で、左右のシャント組織の抽出を行い、血管断面の病理観察を行った。その結果、③にてwall shear stressが発生した場所において狭窄(内膜肥厚)が始まっていたため、シャント内で発生するwall shear stressは狭窄の要因であることが示唆された。

  9. 3Dプリンタ用PVA材料の構造および熱物性と適応部位の解明

    太田 信, 岡本 吉弘, 安西 眸, 庄島 正明, TUPIN SIMON

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

    研究種目:Grant-in-Aid for Scientific Research (B)

    研究機関:Tohoku University

    2020年4月1日 ~ 2023年3月31日

  10. 脳動脈瘤の進展・破裂抑止と弾性壁効果

    山口 隆平, 田中 学, 太田 信, TUPIN SIMON, 安西 眸

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)

    研究種目:Grant-in-Aid for Scientific Research (C)

    研究機関:Tohoku University

    2019年4月1日 ~ 2022年3月31日

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    脳動脈瘤の進展・破裂の予測精度を向上させるため、本来柔軟な瘤壁の弾性の影響を検討すべく、薄膜弾性の小さな脳動脈瘤を十分に再現できる作製法を確立した。この薄膜弾性の実寸 Phantom modelと、セットする最適なBathの組合せを再現できた。この研究の主要なポイントは、血管壁と同じ弾性係数を持つ直径7~10mm程度の透明な実動脈瘤 Phantomの作製である。この確立により、血流の拍動に伴う膨張・収縮変形の再現が可能となった。測定項目は、動脈瘤の進展、破裂に至る血行力学的因子である壁せん断応力WSS(Wall Shear Stress)、壁せん断応力の空間勾配 WSSG (Gradient of WSS)、流れの不安定性(Flow Instability)、また計算流体力学CFD(Computational Fluid Dynamics)による瘤底部での淀みに伴う血流の滞留時間 RRT(Residual Residence Time)の実験・解析した。 WSSの瘤壁に沿う勾配(WSSG)が淀み点回りで極めて大きくなること、この効果を調査するため、剛体モデルも作製した。対象となる中大脳動脈瘤である。WSSの抑制と、瘤入口から瘤底部に衝突する淀み点回りで、WSSの瘤壁に沿う勾配 (WSSG) が極めて大きくなることから、淀み点回りに作用するTensile forceが破裂の一因になる。さらに、剛体と弾性壁モデルでは、低レイノルズ数の拍動に伴うFlow Instability の指標の一つである運動エネルギ減衰率(KEC: Kinetic Energy Cascade)が、低周波及び高周波数域で弾性壁の減少勾配と減衰率は 10^-1~10^-2と大きく減衰すること。Flow Instabilityは剛体壁に限定され、弾性を考慮した実験は少なく、解析法はない。

  11. 革新的脳血管治療デバイス:フローダイバーターの省資源非臨床評価システムの構築

    岡本 吉弘, 中村 匡徳, 太田 信

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research

    研究種目:Grant-in-Aid for Scientific Research (C)

    研究機関:National Institute of Health Sciences

    2017年4月1日 ~ 2022年3月31日

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    本年度は、フローダイバーターの入手が困難なため、デバイスから血管へかかる圧力を測定する評価系の構築を目的とし、評価装置の設計および予備的検討を実施した。デバイスとしてはバルーンカテーテルを用いることとして、直線状態の血管での圧力を評価した。評価方法としては、薄肉円筒における応力に関する式を活用した評価系を検討した。検討した結果、バルーンの内圧に対してバルーンから血管が受ける圧力には違いがあることが判明し、バルーンの規定径近辺における血管にかかる圧力は、バルーンの内圧に対して小さいことが明らかになった。現在検討している評価系は電子天秤を用いた簡易型の評価系であるため、バルーンからの荷重が大きい場合は荷重による変形が生じ、評価を実施する径に対して評価時の径が大きくなってしまう問題があることも判明した。問題への対策として、より構造が強固な万能試験機を用いた評価系とするために必要な機器の設計・製作を行なった。この評価装置を用いた実験では、今までの装置と同条件において高い圧力が測定され、より精度の高い評価ができることが確認された。 デバイスから血管へ圧力を測定する評価系としては、別途小型フィルムセンサーを血管モデルに設置した評価系を検討し、直接圧力を測定することを試みた。同じ径の硬さが異なる血管において同じバルーンカテーテルを用いた圧力測定を実施し、柔らかい血管でのバルーンから受ける圧力はバルーンの内圧より低いことを確認した。

  12. 新規動脈血管モデルを組み込んだ頭頸部循環における拍動循環シミュレータ構築の試み 競争的資金

    坪子 侑佑, 岡本 吉弘, 太田 信

    提供機関:Institute of Fluid Science, Tohoku University

    制度名:Collaborative Research Project of the Institute of Fluid Science, Tohoku University

    研究機関:Waseda University

    2021年4月 ~ 2022年3月

  13. 多層性血流制御ステントによる解離性大動脈瘤治療のための流体力学的基礎研究

    鈴木 佑輔, 太田 信, 齋木 佳克, 高瀬 圭, 熊谷 紀一郎

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)

    研究種目:Grant-in-Aid for Scientific Research (C)

    研究機関:Tohoku University

    2018年4月1日 ~ 2021年3月31日

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    解離血管モデルを作成した。疑似解離血管モデルを組み込んだ拍動流循環回路を設計した。真腔内にMFMステントを留置する前後で血行動態の解析を行なった。その結果、MFMステント留置前の偽腔では拍動した水流を認め、エントリー部では加速水流を認めた。一方、MFMステント留置後は、ほぼ層流となり、加速水流を認めなかった。以上より偽腔内への水流は残存するが、このMFMステントを通して偽腔内へ流入する水流が整流化され乱流が減少し、偽腔壁へかかるずり応力が減少するだろうと考えられた。この結果より解離性大動脈瘤に対する治療としてMFMステントは有用である可能性が示された。

  14. ヘルスケア衣環境のための光ファイバセンサを導入したウェアラブルシステム

    石澤 広明, 高寺 政行, 太田 信, 児山 祥平, 坂口 明男, 藤本 圭作, 鈴木 大介, 細谷 聡

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)

    研究種目:Grant-in-Aid for Scientific Research (A)

    研究機関:Shinshu University

    2016年4月1日 ~ 2021年3月31日

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    ファイバブラッググレイティング(FBG)や熱電対センサアレイを応用し,血糖値,血圧値,呼吸数,体温を連続測定可能なスマートテキスタイルに可能性を拓いた. 脈動点において測定した脈波形状の特徴から,血糖値や血圧の連続測定が可能であることを明らにした.洗濯が可能なテキスタイルへの適用のため,プラスティック光ファイバFBGの利用が可能であること,石英系FBGの構造糸とこの織編技術により,肘用サポータやアンダーウェアへのセンサの導入が可能であることを明らかにした.試作開発したテキスタイルは、着用状態や着用者の生理的状態を測定・評価可能であり,ヘルスケアを支援するための衣環境の確立に可能性を拓いた.

  15. 動脈瘤壁の治癒と穿通枝温存を両立する紡錘状動脈瘤治療用ステントの開発

    遠藤 英徳, 太田 信, 仲井 正昭, 荒船 龍彦, 安西 眸, 大谷 清伸

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)

    研究種目:Grant-in-Aid for Scientific Research (C)

    研究機関:Tohoku University

    2017年4月1日 ~ 2020年3月31日

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    紡錘状脳動脈瘤の臨床例に対して、流体力学解析を行い、動脈瘤の壁におけるストレスデータの標準化を行った。続いて、流体工学的に動脈瘤壁から出血を起こしにくい条件、しかも、動脈瘤から分岐する細血管の開存が維持される条件を算出し、ステントデザインを検討した。さらに、プロトタイプのステントを用いて、ブタ紡錘状動脈瘤モデルに留置した場合に内部を流入する血流データをシミュレーションし、ステントデザイン適正性の検討を行った。

  16. 形態・機能画像と数値流体力学による慢性血栓塞栓性肺高血圧症の肺血流解析

    大田 英揮, 太田 信, 杉村 宏一郎

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)

    研究種目:Grant-in-Aid for Scientific Research (C)

    研究機関:Tohoku University

    2016年4月1日 ~ 2019年3月31日

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    本研究では,慢性血栓塞栓性肺高血圧症に対して4D flow MRIとデュアルエナジーCTから,肺血流の解析を行った.具体的には,1)慢性血栓塞栓性肺高血圧症に対する肺動脈血管拡張術前後において,デュアルエナジーCTの画像を解析し,血液分布を反映するCT造影剤の分布が,肺実質内で有意に変化し,肺動脈圧とその分布に相関があることを示した.2)4D flow MRIを用いて,肺動脈血管形成術前後における数値流体力学的パラメータを比較したところ,壁せん断応力が治療後に上昇したことが確認できた.また,その変化度は,肺動脈圧の変化度と相関していた.

  17. スタンフォードB型解離の大動脈径拡大のメカニズムの解析と予測方法の開発

    吉岡 一朗, 齋木 佳克, 熊谷 紀一郎, 藤原 英記, 太田 信

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)

    研究種目:Grant-in-Aid for Scientific Research (C)

    研究機関:Tohoku University

    2016年4月1日 ~ 2019年3月31日

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    研究を始めるにあたってB型大動脈解離の治療成績を再評価を行った。CTで解離の形態を分離してみたところで現状の形態解析だけではやはりその拡大を予測することが難しいことが再確認された。 CTデータから得られる大動脈の形態構築とMRI検査から得られる流速条件から有限要素解析法を用いた壁せん断応力の解析を試みた。しかし大動脈解離のintimal flapの動きについては、4DのMRI検査で急性期においては慢性期に比して 動きが非常に大きいことが分かり、これを流体解析のなかで組み込むことは困難であることが分かり、大動脈解離の初期段階で拡大予測を行うことが困難であることが分かった。

  18. 流れ付加中におけるステント最適化デザイン表面の内皮細胞付着の解明(国際共同研究強化)

    太田 信, セン イツ, ヒルシュ スベン, フレデリッヒ バンサン

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Fund for the Promotion of Joint International Research (Fostering Joint International Research)

    研究種目:Fund for the Promotion of Joint International Research (Fostering Joint International Research)

    研究機関:Tohoku University

    2016年 ~ 2018年

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    3カ所で行われた海外共同研究は,ステントのスマートディプロイメントプログラムの開発,動脈瘤の効率的な発見方法の開発,壁せん断応力による細胞の応答に関する知見,及び新たな生体モデル材料の開発に繋がった.これらを総合して,流れが付加された状況において,ステントストラットにより流れが変化することに対応して内皮細胞の分布が変化することを突き止めることに成功し,細胞に最適なストラットの状態あることを示した.このことは,2019年の国際会議と論文で発表された.他の研究成果と統合することで,動脈瘤の診断から最適なステントデザイン提示までのパイプラインの構築が可能になった.

  19. 流れ付加中におけるステント最適化デザイン表面の内皮細胞付着の解明

    太田 信, 岩田 博夫, 小林 尚俊

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

    研究種目:Grant-in-Aid for Scientific Research (B)

    研究機関:Tohoku University

    2013年4月1日 ~ 2016年3月31日

    詳細を見る 詳細を閉じる

    本研究の成果は,ステントの最適デザインプログラムの開発と,ステントワイヤの表面処理による内皮化の成功である.次世代ステントは,再狭窄や再開通など,再罹患が起こらないことが重要な課題である.内皮化を素早く行うことが本問題を解決するものとして注目されている.本問題に対し,本研究ではステントデザインの最適化と表面処理によって解決を試みた.その結果,我々が開発した表面処理法によりステント表面に内皮細胞の増殖と移動を促すことを突き止めた.さらに,血栓化を誘起する最適化デザインを設計を可能とするプログラムを開発した.これにより,血流減少率が最大のステント形状を開発することに成功した.

  20. 数値流体解析に基づく脳動脈瘤壁性状診断、破裂リスク予知と、治療への応用

    新妻 邦泰, 杉山 慎一郎, 中川 敦寛, 早瀬 敏幸, 太田 信, 船本 健一, 荒船 龍彦, 鷲尾 俊克

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (A)

    研究種目:Grant-in-Aid for Young Scientists (A)

    研究機関:Tohoku University

    2013年4月1日 ~ 2016年3月31日

    詳細を見る 詳細を閉じる

    本研究の目的は、数値流体力学的解析結果を含む大規模脳動脈瘤データベースを構築し、これにデータマイニング手法を適用し、動脈瘤壁の性状や破裂リスクを算定することである。3年間の研究でデータベース登録を進め、当初予定していたものよりも多い500例規模のものが完成した。本データベースを用いて、動脈瘤の黄色調で固い壁の部位を数値流体力学から予測しうることを報告した。また、特定の脳底動脈瘤を対象に、破裂と血行動態の関連(論文投稿中)や、コイル塞栓術後の再発と血行動態の関連(論文投稿中)などの知見も得られた。 データマイニング手法を適用した解析と動脈瘤の血行評価を行う外来システムは解析中・構築検討中である。

  21. 副腎静脈サンプリングにおける超選択的採血システムの開発

    清治 和将, 高瀬 圭, 森本 玲, 太田 信, 芳賀 洋一, 中村 保宏

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)

    研究種目:Grant-in-Aid for Scientific Research (C)

    研究機関:Tohoku University

    2012年4月1日 ~ 2016年3月31日

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    原発性アルドステロン症での選択的副腎静脈支脈サンプリングにおいて副腎静脈の各支脈からの採血を容易かつ可能にする最適なデバイス(マイクロカテーテル等)の開発を目的として研究を行った。人工血管モデルやワークステーションを用いたシミュレーション環境下で、マイクロカテーテルの先端形状の相違による吸引時の副腎静脈およびマイクロカテーテルの変形や血流の変化について解析を行った。これらの結果を基に、副腎静脈の各支脈からの採血を容易かつ可能にする最適なマイクロカテーテルの試作品を作成し、実験動物を用いてその性能評価を行った。

  22. 次世代の脳動脈瘤治療用ステントのストラットパターンの構築に関する研究

    中山 敏男, 太田 信

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)

    研究種目:Grant-in-Aid for Scientific Research (C)

    2012年4月1日 ~ 2015年3月31日

    詳細を見る 詳細を閉じる

    本研究では“FlowDiverterStent”を超える次世代の脳動脈瘤治療用ステントのストラットパターンを構築する方法を見いだすこと目的とする.そこで,アスペクトレイシオに加えて,親血管形状を考慮した流体力学に基づいた新しい脳動脈瘤の分類方法の提案を行った.これにより,ステント設計の効率が上げることが可能となる.ステント設計に血管壁と動脈瘤壁に柔軟性を持たせる流体構造連成解析の導入する.流体構造連成解析を導入することで,これまでの数値流体力学解析より精度高いシミュレーションが可能となり,人に適した脳動脈瘤用ステントの開発が可能となる.次世代ステントストラットパターンを見いだす方法を開発した.

  23. 副腎静脈サンプリングを応用した原発性アルドステロン症の低侵襲根治術用器具開発

    高瀬 圭, 太田 信, 森本 玲, 清治 和将, 佐藤 文俊, 佐藤 美帆, 芳賀 洋一, 山内 清

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

    研究種目:Grant-in-Aid for Scientific Research (B)

    研究機関:Tohoku University

    2011年4月1日 ~ 2014年3月31日

    詳細を見る 詳細を閉じる

    3DCTデータを基に、実際のカテーテル手技訓練の実用に耐える副腎内静脈分枝を含んだ実物大副腎静脈血管モデルが作成された。バイポーラーラジオ波焼灼針では、10-25mmの副腎腺腫は、3通りの穿刺パターンにて完全焼灼可能であることと、脂肪組織介在下での周辺臓器安全性が示された。IVR臨床治療を施行し、主要評価項目である血中および蓄尿中アルドステロンを正常化が得られ、研究当初の臨床応用目標が達成された。モデル解析にて医療経済的にも有利であるとの結果を得た。

  24. 計測融合連成解析による生体内血流場の経時的挙動の解明

    早瀬 敏幸, 白井 敦, 太田 信

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research

    研究種目:Grant-in-Aid for Scientific Research (B)

    研究機関:Tohoku University

    2007年 ~ 2009年

    詳細を見る 詳細を閉じる

    本研究課題は、生体内の血管内部の条件が未知の場合でも、医療用超音波診断装置の計測結果をコンピュータシミュレーションにフィードバックすることにより、生体内の血管や血流の状態を正確に再現する手法を構築して、生体内の経時変化を解明し、循環器系疾患の発生メカニズムや治療法の解明に貢献することを目標として実施した。本研究により、動脈硬化や血管狭窄などを予測できる新たな診断指標が明らかとなり、循環器系疾患の経時変化を正確に評価できる可能性が示された。

  25. シネマティックアンギオを用いた脳動脈瘤内の血流フローダイナミクス計測法の開発

    太田 信

    2006年 ~ 2007年

    詳細を見る 詳細を閉じる

    脳動脈瘤の血管内治療では、血流速度を減少させ、治癒を行うことが一般的となっている。血流速度を測定することは、治療方法の策定および検証に非常に大切である。しかしながら、治療中治療後も含めて血流速度を測定できる方法は今まで皆無であった。 本研究では、治療中、治療後も同一の条件で使用する血管造影装置からの連続画像を用いたVortex Center Path line method (VCP)法を考案し、実用プログラムの作成を行い、その有効性を検証した。具体的には,治療の際に用いられる血管造影装置で得られた画像から,流体力学と画像情報処理に基づいた血管造影剤の渦軌跡を追跡することにより,動脈瘤内の血流速度を計測する方法を開発した。このような流体力学の手法と画像処理といった工学的なアプローチを適用したことに本研究の特色がある。 本結果は第4回国際イントラクラニアルステント学会(京都)において、「Quantification of Flow in aneurysm for Development of Intracranial Stent」と題して招待講演に選ばれた。さらに、実際の臨床の現場において、脳動脈瘤の発生・成長に関する血流の影響を調べるため、血流数値流体解析との組み合わせ、血流状態を調べる新たな共同研究を行った。この結果は第32回日本脳神経血管内治療学会(神戸)において発表され、演者がポスター賞(銀賞)を受賞するなど、基礎医学だけでなく、実際の臨床現場にも多大な影響与え貢献をした。

  26. 医工学 競争的資金

    制度名:International Joint Research Projects

    2001年9月 ~

︎全件表示 ︎最初の5件までを表示

社会貢献活動 7

  1. 第9回CVC 千葉血管障害の原点を考える会

    2015年11月4日 ~

  2. みやぎ県民大学

    2014年8月29日 ~

    詳細を見る 詳細を閉じる

    血液の流れを講演する

  3. 宮城県民大学

    2009年9月25日 ~

  4. みやぎ県民大学

    2009年9月11日 ~

    詳細を見る 詳細を閉じる

    みやぎ県民大学で,公開講座を行った

  5. 仙台市出前授業

    2005年12月19日 ~

    詳細を見る 詳細を閉じる

    仙台市立松森小学校に出前授業を行った

  6. 仙台市の出前授業

    2005年12月15日 ~

    詳細を見る 詳細を閉じる

    仙台市立川前小学校に出前授業に行った

  7. みやぎ県民大学

    2005年9月8日 ~

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    みやぎ県民大学で,公開講座を行った

︎全件表示 ︎最初の5件までを表示

メディア報道 6

  1. Blue Practice 血管内手技の向上を支援

    日刊工業新聞

    2022年2月22日

    メディア報道種別: 新聞・雑誌

  2. 東北大発新興、センサー搭載の血管モデル 医師の練習用

    日本経済新聞

    2022年2月22日

    メディア報道種別: インターネットメディア

  3. コロナ感染者を車で運ぶにはエアコンは外気導入で窓を閉める 東北大学の研究 執筆者本人

    khb東日本放送

    2022年2月15日

    メディア報道種別: テレビ・ラジオ番組

  4. 車内の感染リスク・・・運転席を「閉めた方」が有効 感染が疑われる家族を乗せ運転する場合は? 執筆者本人

    仙台放送

    2022年2月9日

    メディア報道種別: テレビ・ラジオ番組

  5. Blue Practice 血管内手技の向上

    日刊工業新聞

    2022年1月17日

    メディア報道種別: 新聞・雑誌

  6. 感触,実物そっくり 歯科向け口腔模型を開発

    河北日報

    2007年6月4日

    メディア報道種別: 新聞・雑誌

    詳細を見る 詳細を閉じる

    感触,実物そっくり 歯科向け口腔模型を開発

︎全件表示 ︎最初の5件までを表示

学術貢献活動 7

  1. Frontiers

    学術貢献活動種別: 査読等

  2. Cardiovascular Engineering and Technology

    学術貢献活動種別: 査読等

  3. PLOS ONE

    学術貢献活動種別: 査読等

  4. International Journal for Numerical Methods in Biomedical Engineering

    学術貢献活動種別: 査読等

  5. Evaluation of aneurysm rupture risk based upon flowrate-independent haemodynamic parameters: a multi-centre pilot study

    学術貢献活動種別: 査読等

  6. Technology and Health care

    学術貢献活動種別: 査読等

    詳細を見る 詳細を閉じる

    Deputy Editors-in-Chief

  7. 日本機械学会学術誌

    学術貢献活動種別: 学会・研究会等

    詳細を見る 詳細を閉じる

    新学術誌編修委員会 委員 査読

︎全件表示 ︎最初の5件までを表示

その他 40

  1. 大動脈瘤用ステントグラフトのインビトロ試験

    詳細を見る 詳細を閉じる

    大動脈瘤用ステントグラフトのインビトロ試験を行う

  2. 骨髄液流れ

    詳細を見る 詳細を閉じる

    骨髄液の流れをモデル化する

  3. ステント内流れ計測

    詳細を見る 詳細を閉じる

    ステント内の流れをMRI,PIV,CFDで計測する

  4. 歯垢除去法の開発

    詳細を見る 詳細を閉じる

    歯垢除去法の開発

  5. コイルモデル内ながれの可視化

    詳細を見る 詳細を閉じる

    コイルモデル内の流れの可視化実験

  6. 副腎診カテ吸引試験

    詳細を見る 詳細を閉じる

    副腎に用いる診カテの吸引能力を調べる

  7. 足モデルの開発

    詳細を見る 詳細を閉じる

    ストッキングの締め付けを測定する足型のモデルを開発する

  8. 骨ドリルモデルの開発

    詳細を見る 詳細を閉じる

    骨のドリル試験に用いる模擬骨の解析

  9. アブレーションカテーテルの生体組織への温度分布測定

    詳細を見る 詳細を閉じる

    アブレーションカテーテルの生体組織への温度分布測定

  10. ブドウ球菌の2成分性毒素γヘモリジンが形成するヘテロヘプタマー膜孔複合体血球脆弱化に関する研究

    詳細を見る 詳細を閉じる

    ブドウ球菌の2成分性毒素γヘモリジンが形成するヘテロヘプタマー膜孔複合体血球脆弱化に関する研究

  11. コイルが留置された脳動脈瘤モデル内の流れに関する研究

    詳細を見る 詳細を閉じる

    コイルが留置された脳動脈瘤モデル内の流れに関する研究

  12. 脳動脈瘤用ステントの最適化設計

    詳細を見る 詳細を閉じる

    脳動脈瘤用ステントの最適化設計

  13. カテーテルの挙動に関する研究

    詳細を見る 詳細を閉じる

    カテーテルの挙動に関する研究

  14. PVAハイドロゲルの摩擦特性に関する研究

    詳細を見る 詳細を閉じる

    PVAハイドロゲルの摩擦特性に関する研究

  15. 狭窄血流に関する研究

    詳細を見る 詳細を閉じる

    狭窄血流に関する研究

  16. 3次元可視化システムを用いた血流数値解析の可視化

    詳細を見る 詳細を閉じる

    3次元可視化システムを用いた血流数値解析の可視化

  17. 歯科模型に関する共同研究

    詳細を見る 詳細を閉じる

    歯科模型を開発する

  18. カテーテルの挙動に関する研究

    詳細を見る 詳細を閉じる

    カテーテルの挙動に関する研究

  19. コイル後の脳動脈瘤内の血流に関する研究

    詳細を見る 詳細を閉じる

    コイル後の脳動脈瘤内の血流に関する研究

  20. 血管モデルの摩擦に関する研究

    詳細を見る 詳細を閉じる

    血管モデルの摩擦に関する研究

  21. 口腔粘膜モデルの摩擦に関する研究

    詳細を見る 詳細を閉じる

    口腔粘膜モデルの摩擦に関する研究

  22. ステントの最適化

    詳細を見る 詳細を閉じる

    ステントの最適化

  23. 血流阻害用脳動脈瘤用ステントの開発

    詳細を見る 詳細を閉じる

    血流阻害用脳動脈瘤用ステントの開発

  24. 血管狭窄内の血流に関する技術提供

    詳細を見る 詳細を閉じる

    血管狭窄内の血流に関する技術提供

  25. 医薬品・医療機器等レギュラトリーサイエンス総合研究事業 医療機器・医用材料のリスクアセスメント手法開発に関する研究

    詳細を見る 詳細を閉じる

    医療機器・医用材料のリスクアセスメント手法開発に関する研究

  26. 歯科模型に関する共同研究

    詳細を見る 詳細を閉じる

    歯科模型を開発する

  27. 頸動脈中の血流

    詳細を見る 詳細を閉じる

    頸動脈中の血流を測定と数値流体解析で整合性を調べる

  28. 血流の数値流体解析の整合性

    詳細を見る 詳細を閉じる

    血流の数値流体解析の整合性を調べる

  29. 脳動脈瘤および脳内疾患における手術シミュレーションの研究開発

    詳細を見る 詳細を閉じる

    脳動脈瘤および脳内疾患における手術シミュレーションについて研究および開発することを目的とする.3次元プリンターを用いた構造創製を目指し,サブミリでの制御を目指す.

  30. 歯科に関する共同研究

    詳細を見る 詳細を閉じる

    歯科バイオモデリングに関する共同研究

  31. 造影剤の拡散について

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    脳動脈瘤内の造影剤の拡散についてシミュレーションを行う

  32. ナノ粒子の熱測定

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    ナノ粒子の熱測定を行う

  33. PVA粘膜型食道ステントの開発

    詳細を見る 詳細を閉じる

    PVA粘膜型食道ステントの開発を行う

  34. 医療分野に関する共同研究

    詳細を見る 詳細を閉じる

    バイオモデリングの開発

  35. PIVによる脳動脈瘤内の血流測定

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    PIVによる脳動脈瘤バイオモデリング内の血流測定

  36. 脳動脈瘤バイオモデリング

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    脳動脈瘤のバイオモデリングを作成する

  37. 動脈瘤の動きについて

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    動脈瘤の動きについて,測定する

  38. マイクロカテーテルのコンピュータシミュレーション

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    マイクロカテーテルのコンピュータシミュレーションによる,動作予測を行う.

  39. 4D-CTの画像評価

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    4D-CTの画像評価を行う方法を開発する

  40. PVAを用いた大動脈瘤のバイオモデリングの開発

    詳細を見る 詳細を閉じる

    PVAを用いた大動脈瘤のバイオモデリングを開発する

︎全件表示 ︎最初の5件までを表示