TOHOKU UNIVERSITY Researchers

Yoshifumi Saijo

Section

Graduate School of Biomedical Engineering

Job title

Professor

Degree

博士（医学）（東北大学）

researchmap

https://researchmap.jp/read0055327

J-GLOBAL ID

200901012521948619

Education 2

Tohoku University　Graduate School of Medicine

- 1993/03
Tohoku University　School of Medicine

- 1988/03

Committee Memberships 4

一般社団法人東北臨床研究審査機構共同臨床研究審査委員会　委員長

2018/04 - Present
一般財団法人公正研究推進協会（APRIN）　中等教育教材作成分科会委員

2017/11 - Present
公益社団法人日本超音波医学会　代議員

2006/05 - Present
一般社団法人日本心エコー図学会　代議員

2003/10 - Present

Professional Memberships 3

The Japan Society of Ultrasonics in Medicine(2006/05-2008/05 )
日本栓子検出と治療学会(2002/10- 世話人)
日本心エコー図学会(2003/10- 評議員)

Research Interests 3

cardiology
medical ultrasound
Biomedical imaging

Research Areas 4

Life sciences / Biomaterials / Biomedical Engineering
Life sciences / Biomedical engineering / Biomedical Engineering
Life sciences / Cardiology / Cardiology
Life sciences / Medical systems /

Awards 9

Clinical Prize 1997

1998/01　World Federation for Ultrasound in Medicine and Biology　Ultrasonic tissue characterization of infarcted myocardium by scanning acoustic microscopy
Symposium on Ultrasonic Electronics 2021: Best Paper Award

2022/11　Symposium on Ultrasonic Electronics　Comparative investigation of coherence factor weighting methods for an annular array photoacoustic microscope
Symposium on Ultrasonic Electronics 2019: Best Paper Award

2020/11　Symposium on Ultrasonic Electronics　Development of optical resolution photoacoustic microscopy with sub-micron lateral resolution for visualization of cells and their structures
The 15th Ito Award

2020/05　Role of intra-ventricular vortex in left ventricular ejection elucidated by echo-dynamography.
Symposium on Ultrasonic Electronics 2017: Best Paper Award

2018/11　Symposium on Ultrasonic Electronics　Singular value decomposition of received ultrasound signal to separate tissue, blood flow, and cavitation signals
Korea Artificial Organ Center Award

2006/08/28　Korea Artificial Organ Center　Evaluation of Cardiac Function of the Patients with Left Ventricular Assist Device by Transesophageal Echocardiography
The CCT 2004 Award for Excellence

2004/10/21　CCT　Ultrasonic tissue characterization of flow limiting thrombus in acute myocardial infarction by acoustic microscopy.
Outstanding Paper Award: 2003 Northern Region Congress of Asia Pacific Orthopaedic Association.

2003/12/05　アジア太平洋整形外科学会
Best Poster Award , 13th Roterdam Conference on Echocardiology

1999/06/23　ロッテルダム心エコー学会

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Papers 449

Testbed mimicking intracellular environment for optical-resolution photoacoustic microscopy

Daisuke Nishimae, Takuro Ishii, Koetsu Ogasawara, Yoshifumi Saijo

Japanese Journal of Applied Physics　2024/03/25
Publisher: IOP Publishing
DOI： 10.35848/1347-4065/ad3761 　

ISSN：0021-4922

eISSN：1347-4065

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Abstract Photoacoustic imaging (PAI) represents an innovative method that utilizes optics for transmission and acoustic for sensing. Within the realm of PAI modalities, optical-resolution photoacoustic microscopy (OR-PAM) stands out for its ability to achieve high-resolution cellular and intracellular imaging. However, an optical testbed setup emulating the intracellular environment and accelerating the development of cellular-level OR-PAM systems has not been established. In this study, we present a testbed setup designed to mimic intracellular conditions. Assessment of this testbed setup efficacy involved embedding photoacoustic contrasts and imaging them using an OR-PAM system. The imaging results show that our testbed setup can provide instrumental in accurately measuring photoacoustic signals within an intracellular aqueous environment, avoiding risks of the contamination and degradation of the acoustic transducer.
Effects of diameter of optical absorber visualized by an annular array AR-PAM system on spectrum characteristics of photoacoustic signals

Riku Suzuki, I Gede Eka Sulistyawan, Takuro Ishii, Yoshifumi Saijo

Japanese Journal of Applied Physics　2024/03/21
Publisher: IOP Publishing
DOI： 10.35848/1347-4065/ad3650 　

ISSN：0021-4922

eISSN：1347-4065

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Abstract Spectrum characteristics of photoacoustic signals are potential indicators to assess the structural information of optical absorbers. This study investigated whether a spectrum analysis approach can evaluate microvascular diameters obtained by an annular array AR-PAM system. First, 2D numerical simulations were performed to estimate spectral changes in five absorbers with different diameters from 30 µm to 200 µm. Slope and intercept values from the regression line of the spectrum curve were calculated. Second, the estimated changes were validated by acquiring photoacoustic signals from tungsten wires with five different diameters. Both in numerically and experimentally, spectrum analysis showed the larger the diameter, the greater the lower frequency components, resulting in steeper slope and greater intercept values. Finally, photoacoustic signals acquired from cutaneous microvessels were analyzed. The FWHM diameter of the vessels were corresponded to the slope (r= -0.595; p< 0.05) and intercept (r= 0.657; p< 0.05) values, respectively.
Superficial Bifurcated Microflow Phantom for High-Frequency Ultrasound Applications

Anam Bhatti, Takuro Ishii, Yoshifumi Saijo

Ultrasound in Medicine & Biology　50　(1)　158-164　2024/01
Publisher: Elsevier BV
DOI： 10.1016/j.ultrasmedbio.2023.10.002 　

ISSN：0301-5629
Ultrasound vector flow imaging during veno-arterial extracorporeal membrane oxygenation in a thoracic aorta model

Kenichiro Yambe, Takuro Ishii, Billy Y. S. Yiu, Alfred C. H. Yu, Tomoyuki Endo, Yoshifumi Saijo

Journal of Artificial Organs　2023/07/20
Publisher: Springer Science and Business Media LLC
DOI： 10.1007/s10047-023-01413-z 　

ISSN：1434-7229

eISSN：1619-0904

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Abstract In veno-arterial extracorporeal membrane oxygenation (VA-ECMO) treatment, the mixing zone is a key hemodynamic factor that determines the efficacy of the treatment. This study aimed to evaluate the applicability of a novel ultrasound technique called vector flow imaging (VFI) for visualizing complex flow patterns in an aorta phantom under VA-ECMO settings. VFI experiments were performed to image aortic hemodynamics under VA-ECMO treatment simulated in an anthropomorphic thoracic aorta phantom using a pulsatile pump (cardiac output: 2.7 L/min) and an ECMO pump with two different flow rates, 0.35 L/min and 1.0 L/min. The cardiac cycle of hemodynamics in the ascending aorta, aortic arch, and descending aorta was visualized, and the spatio-temporal dynamics of flow vectors were analyzed. VFI successfully visualized dynamic flow patterns in the aorta phantom. When the flow rate of the ECMO pump increased, ECMO flow was more dominant than cardiac output in the diastole phase, and the speed of cardiac output was suppressed in the systole phase. Vortex flow patterns were also detected in the ascending aorta and the arch under both ECMO flow rate conditions. The VFI technique may provide new insights into aortic hemodynamics and facilitates effective and safe VA-ECMO treatment.
Evaluation of temperature-dependent fluctuations in skin microcirculation flow using a light-emitting diode based photoacoustic imaging device

Yosuke Ito, Takuro Ishii, Shin Yamazaki, Akiko Yoshida, Kei Nagaya, Yoshifumi Saijo

Journal of Clinical Monitoring and Computing　2023/05/11
Publisher: Springer Science and Business Media LLC
DOI： 10.1007/s10877-023-01026-0 　

ISSN：1387-1307

eISSN：1573-2614
Ultrasound flow phantom for transcranial Doppler: An assessment of angular mismatch effect on blood velocity measurement in comparison to optical particle image velocimetry

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

Frontiers in Physics　11　2023/04/06
Publisher: 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.
A study on correction method of total acoustic power in presence of shielding in focused ultrasound treatment using acoustic radiation force imaging

Erika Numahata, Shin YOSHIZAWA, Shin-ichiro UMEMURA, Takuro Ishii, Yoshifumi Saijo

Japanese Journal of Applied Physics　2023/03/20
Publisher: IOP Publishing
DOI： 10.35848/1347-4065/acc595 　

ISSN：0021-4922

eISSN：1347-4065

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Abstract High-intensity focused ultrasound (HIFU) therapy is a noninvasive treatment for cancer. Prediction of the HIFU treatment region in advance by ultrasound imaging is important for the efficacy and safety of the treatment. Acoustic radiation force (ARF) imaging has been shown to be useful in estimating the heat distribution caused by HIFU. In this study, we investigated the effect of shielding on the estimated heat distribution when the propagation of HIFU is partially shielded by an object simulating ribs, imitating an actual clinical situation, and examined the correction method of HIFU output power using ARF imaging to obtain tissue coagulation equivalent to that without shielding. As a result, it was suggested that even with partial acoustic shielding, when the HIFU output power is adjusted so that the displacement induced by ARF is equal to that without shielding, almost the same coagulated region can be obtained as in the unshielded case.
Utilization of Curvelet Transform in Reconstructing Cellular Images for Undersampled Optical-resolution Photoacoustic Microscopy

I Gede Eka Sulistyawan, Daisuke Nishimae, Takuro Ishii, Yoshifumi Saijo

IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control　1-1　2023
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
DOI： 10.1109/tuffc.2023.3272917 　

ISSN：0885-3010

eISSN：1525-8955
Robust flow vector estimation for echocardiography with extended Nyquist velocity using dual-PRF approach: A flow phantom study Peer-reviewed

Yuki Okada, Naoya Kanno, Anam Bhatti, Takuro Ishii, Yoshifumi Saijo

Japanese Journal of Applied Physics　in press　2023

DOI： 10.35848/1347-4065/acbda6 　
Application of Scanning Acoustic Microscopy for Detection of Dental Caries Lesion

Yukihiro Naganuma, Kouki Hatori, Masahiro Iikubo, Masatoshi Takahashi, Yoshihiro Hagiwara, Kazuto Kobayashi, Atsushi Takahashi, Kumi Hoshi, Yoshifumi Saijo, Keiichi Sasaki

Open Journal of Stomatology　13　(01)　12-24　2023
Publisher: Scientific Research Publishing, Inc.
DOI： 10.4236/ojst.2023.131002 　

ISSN：2160-8709

eISSN：2160-8717
Region-based SVD Processing of High-frequency Ultrafast Ultrasound to Visualize Cutaneous Vascular Networks

Anam Bhatti, Takuro Ishii, Naoya Kanno, Hayato Ikeda, Kennichi Funamoto, Yoshifumi Saijo

Ultrasonics　129　106907-106907　2022/12
Publisher: Elsevier BV
DOI： 10.1016/j.ultras.2022.106907 　

ISSN：0041-624X
体外衝撃波による膝関節拘縮の予防効果ラット拘縮モデルを用いた検討

岩津潤, 萩原嘉廣, 矢部裕, 金澤憲治, 板谷信行, 曽木靖仁, 西條芳文, 相澤俊峰

日本整形外科学会雑誌　96　(8)　S1668-S1668　2022/09
Publisher: (公社)日本整形外科学会
ISSN：0021-5325
The effects of hydroxyethyl starch 130/0.4 on perioperative renal function in patients undergoing cardiac surgery: A randomised controlled trial Peer-reviewed

Kei Nagaya, Akiko Yoshida, Yosuke Ito, Suguru Watanabe, Tadanori Minagawa, Yoshifumi Saijo

Annals of Medicine and Surgery　81　104475-104475　2022/09
Publisher: Elsevier BV
DOI： 10.1016/j.amsu.2022.104475 　

ISSN：2049-0801
Extracorporeal shockwave therapy in an immobilized knee model in rats prevents progression of joint contracture International-journal Peer-reviewed

Jun Iwatsu, Yutaka Yabe, Kenji Kanazawa, Nobuyuki Itaya, Yasuhito Sogi, Yoshihumi Saijo, Toshimi Aizawa, Yoshihiro Hagiwara

Journal of Orthopaedic Research　41　(5)　951-961　2022/08/28
Publisher: Wiley
DOI： 10.1002/jor.25433 　

ISSN：0736-0266

eISSN：1554-527X

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Joint immobilization, which ensures rest and accelerates tissue recovery in musculoskeletal disorders, often causes joint contracture, for which there is still no effective prevention. To address this, we investigated the effects of extracorporeal shockwave therapy (ESWT) in preventing joint contracture, in a unilaterally immobilized knee rat model. Under general anesthesia, ESWT (0.25 mJ/mm2 , 3000 shot, 4 Hz, 3 days/week) was administered from 1 day after immobilization up to 2, 4, and 6 weeks. The immobilized control group received general anesthesia without ESWT. We evaluated joint angle, tissue elasticity, and gene and protein expression related to fibrosis, inflammation, and angiogenesis in the joint capsule. Relative to the control, the ESWT group had greater joint angle at 4 and 6 weeks, and lower posterior-capsule elasticity at 6 weeks. In the ESWT group, at 6 weeks, gene expression of collagen type I (col1α1), connective tissue growth factor (CTGF), and α-smooth muscle actin (α-SMA) was significantly downregulated, whereas interleukin-6 (IL-6) and hypoxia-inducible factor-1α (HIF-1α) gene expression was upregulated, relative to that in the control. Compared with that in the control, at 4 and 6 weeks, the ratio of CTGF+ cells was significantly lower in the ESWT group; at 4 weeks, the ESWT group had significantly fewer CD68+ cells in the adhesion area, and at 6 weeks, significantly more blood vessels. Statement of Clinical Significance: In a rat model, ESWT counteracted fibrosis, suppressed macrophage infiltration, and promoted neovascularization, reducing elasticity, and increasing joint range-ofmotion. ESWT offers a potential new strategy to prevent progression in joint contracture.
Comparative investigation of coherence factor weighting methods for an annular array photoacoustic microscope Peer-reviewed

Riku Suzuki, Ryo Shintate, Takuro Ishii, Yoshifumi Saijo

JAPANESE JOURNAL OF APPLIED PHYSICS　61　(SG)　2022/07
Publisher: IOP Publishing Ltd
DOI： 10.35848/1347-4065/ac4684 　

ISSN：0021-4922

eISSN：1347-4065

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To achieve fine visualization of the peripheral microvascular networks, we have developed a photoacoustic (PA) microscope equipped with a four-channel annular array transducer. The quality of PA images processed with delay-and-sum (DAS) method is degraded by off-axis signals. Thus, to achieve higher image quality for the PA microscope, this study evaluated the efficacy of the five coherence factor weighting methods: coherence factor, sign coherence factor, phase coherence factor, circular coherence factor, and vector coherence factor. Using PA signals acquired from a 100 mu m microtube and the skin microvessels, we generated PA images with DAS and one of the weighting methods, and quantitatively evaluated the image quality by calculating the sharpness, contrast ratio, and contrast-to-noise ratio. The results showed the phase coherence factor and the vector coherence factor methods were more effective to clearly visualize the microvascular structure, in terms of vessel sharpening and noise suppression performances, than the other methods.
3D ultrasound imaging by synthetic transmit aperture beamforming using a spherically curved array transducer Peer-reviewed

Eiki Hayashi, Naoya Kanno, Ryo Shintate, Takuro Ishii, Ryo Nagaoka, Yoshifumi Saijo

Japanese Journal of Applied Physics　61　(SG)　2022/07/01

DOI： 10.35848/1347-4065/ac51c1 　

ISSN：0021-4922

eISSN：1347-4065

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Visualization of dermal circulation is important in the field of skin healthcare. We have developed a three-dimensional (3D) photoacoustic (PA) imaging system using a spherically curved array transducer that can visualize the microscale circulation in the skin layers, but limited anatomical information was available around the microvasculature. To provide such anatomical information, this study was aimed at devising a high-quality and high-speed ultrasound (US) imaging framework, particularly, for the spherical array transducer. We tested three synthetic transmit aperture (STA) methods, all-elements, outer-track, and inner-track, for transmission by evaluating the spatial resolution and uniformity of 3D images of point and copper-wire targets. The results demonstrated that the all-elements and outer-track STA methods could provide uniform and clear 3D images. In addition, the outer-track STA could be performed with fewer transmissions than the all-elements STA, and it will be useful for realizing real-time, high-resolution 3D PA/US imaging.
High-speed optical resolution photoacoustic microscopy with MEMS scanner using a novel and simple distortion correction method. International-journal Peer-reviewed

Ryo Shintate, Takuro Ishii, Joongho Ahn, Jin Young Kim, Chulhong Kim, Yoshifumi Saijo

Scientific reports　12　(1)　9221-9221　2022/06/02

DOI： 10.1038/s41598-022-12865-3 　

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Optical resolution photoacoustic microscopy (OR-PAM) is a remarkable biomedical imaging technique that can selectively visualize microtissues with optical-dependent high resolution. However, traditional OR-PAM using mechanical stages provides slow imaging speed, making it difficult to biologically interpret in vivo tissue. In this study, we developed a high-speed OR-PAM using a recently commercialized MEMS mirror. This system (MEMS-OR-PAM) consists of a 1-axis MEMS mirror and a mechanical stage. Furthermore, this study proposes a novel calibration method that quickly removes the spatial distortion caused by fast MEMS scanning. The proposed calibration method can easily correct distortions caused by both the scan geometry of the MEMS mirror and its nonlinear motion by running an image sequence only once using a ruler target. The combination of MEMS-OR-PAM and distortion correction method was verified using three experiments: (1) leaf skeleton phantom imaging to test the distortion correction efficacy; (2) spatial resolution and depth of field (DOF) measurement for system performance; (3) in-vivo finger capillary imaging to verify their biomedical use. The results showed that the combination could achieve a high-speed (32 s in 2 × 4 mm) and high lateral resolution (~ 6 µm) imaging capability and precisely visualize the circulating structure of the finger capillaries.
Usefulness of Right Ventricular Free Wall Strain Obtained with Two-Dimensional Speckle-Tracking Echocardiography in Patients with Repaired Tetralogy of Fallot and Pulmonary Regurgitation. Peer-reviewed

Junko Fujiwara, Shunsuke Tatebe, Kotaro Nochioka, Hideki Ota, Yasuharu Funamizu, Takashi Miki, Yoshikatsu Saiki, Satoshi Yasuda, Yoshifumi Saijo

The Tohoku journal of experimental medicine　257　(1)　7-15　2022/05/13

DOI： 10.1620/tjem.2022.J011 　

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Right ventricular (RV) dysfunction caused by chronic pulmonary regurgitation (PR) is a major determinant of clinical outcome in adults with repaired tetralogy of Fallot (rTOF). However, the accurate assessment of RV function by conventional echocardiography remains challenging. This study tested the feasibility and usefulness of RV free-wall (RVFW) strain obtained by two-dimensional (2D) speckle-tracking echocardiography (STE) in evaluation of RV function in adults with rTOF by comparing cardiac magnetic resonance (CMR) imaging. We enrolled 22 consecutive patients (male/female, 8/14; mean age, 25.0 years) with rTOF who underwent transthoracic echocardiography at Tohoku University Hospital from July 2016 to June 2019. We measured RVFW strain by STE and compared them with 22 hemodynamically normal subjects (NOR) (male/female, 9/13; mean age, 32.0 years). The correlation between RV strain and CMR-derived RV ejection fraction (RVEF) or PR fraction (PRF) were also evaluated. All rTOF patients had more than moderate PR but were near asymptomatic. RVFW longitudinal strain (RVFW-LS) was significantly decreased in the rTOF group compared with that in the NOR group (-19.6 vs. -24.7, P < 0.01). In the rTOF group, RVFW-LS correlated with PRF (r = 0.44, P < 0.05), whereas RVFW circumferential strain at the mid-ventricular level correlated with RVEF (r = 0.57, P < 0.01). Intra-observer variability of RVFW strain was acceptable. These results indicate that RV systolic function and PR severity in rTOF could be assessed by RVFW strain measured by 2D STE. This method is feasible and can be used as a complement to CMR imaging.
光音響・高周波超音波東北大学における光音響/高周波超音波イメージング

西條芳文, 新楯諒, 鈴木陸, 石井琢郎, 荒川元孝, 梅村晋一郎, 吉澤晋, 長岡亮, 小林和人, 根本隆治

超音波医学　49　(Suppl.)　S522-S522　2022/04
Publisher: (公社)日本超音波医学会
ISSN：1346-1176

eISSN：1881-9311
光音響顕微鏡の画質向上に寄与するコヒーレンスファクタの検討

鈴木陸, 新楯諒, 石井琢郎, 西條芳文

超音波医学　49　(Suppl.)　S800-S800　2022/04
Publisher: (公社)日本超音波医学会
ISSN：1346-1176

eISSN：1881-9311
Color Doppler shear wave elastography using commercial ultrasound machine with compensated transducer scanning delay. Peer-reviewed

Norma Hermawan, Takuro Ishii, Yoshifumi Saijo

Journal of medical ultrasonics (2001)　49　(2)　163-173　2022/04

DOI： 10.1007/s10396-022-01194-7 　

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PURPOSE: Tissue elasticity can be measured and mapped using color Doppler elastography. In a previous study, a binary pattern of shear waves was observed using a color flow imaging (CFI) system with matched pulse Doppler packet size as well as shear wave frequency and displacement condition. In the present study, we demonstrate the possibility of mapping shear wave velocity and resolving phantom elasticity using any commercial ultrasound machine without fulfilling that condition. METHODS: We derive a relation between Doppler autocorrelator integration time and the estimated flow velocity. The underlying principles behind the shear wave shadows captured by a typical modern ultrasound machine are investigated. The ultrasound machine measurement preset is calibrated to remove the effect of transducer array scanning delay in modifying the appearing wavenumber and thus correct the measurement error. RESULTS: The method was used to successfully measure the elasticity of a biological tissue-mimicking phantom and distinguish a stiff phantom from a soft phantom. CONCLUSION: Using this method, the elasticity of a biological tissue-mimicking phantom can be recovered with less strict constraint. As a result, it provides more flexibility to be implemented in common ultrasound machines. This method may be practically used to help identify tissue stiffness-related disease.
機械走査により得られた高周波数超音波データに対する合成開口焦点技術の適応

井上大和, 菅野尚哉, 新楯諒, 石井琢郎, 小林和人, 西條芳文

電子情報通信学会技術研究報告(超音波)　121　(380)　1-5　2022/02
Publisher: (一社)電子情報通信学会
ISSN：0913-5685

eISSN：2432-6380
Binary Pattern Color Doppler Shear Wave Elastography. International-journal Peer-reviewed

Norma Hermawan, Aoi Sato, Mizuki Fujiwara, Takuro Ishii, Yoshihiro Hagiwara, Yoshiki Yamakoshi, Yoshifumi Saijo

Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual International Conference　2021　3293-3296　2021/11

DOI： 10.1109/EMBC46164.2021.9630967 　

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Some studies suggested a correlation between tissue elasticity and diseases, such as Adhesive Capsulitis (AC) of the shoulder. One category of method to measure elasticity is by utilizing Doppler imaging. This paper discusses color Doppler shear wave elastography methods and demonstrated an experiment with biological tissue mimicking phantom. A simulation with binary pattern color Doppler shear wave elastography shows that wavelength of a shear wave with suggested magnitude is equal to four multiple of pitch strip in a color flow image. However, the larger amplitude changes the duty ratio and frequency of the pattern. An experiment with biological tissue mimicking Polyvinyl Alcohol (PVA) phantoms has shown that the binary pattern color Doppler method has successfully recovered shear wave velocity map and calculate the elasticity.Clinical Relevance-The result of experiments presents a possibility of using the method for quantitatively access the stage of tissue stiffness related disease.
2Pa5-7 3D Ultrasound Imaging by Synthetic Transmit Aperture Beamforming Obtained with a Spherically Curved Array Transducer

Hayashi Eiki, Kanno Naoya, Shintate Ryo, Ishii Takuro, Nagaoka Ryo, Saijo Yoshifumi

Proceedings of Symposium on Ultrasonic Electronics　42　n/a　2021/10/25
Publisher: Institute for Ultrasonic Elecronics
DOI： 10.24492/use.42.0_2pa5-7 　

ISSN：1348-8236

eISSN：2433-1910
3J4-2 Effect of Coherence Factor Weighting for Improving the Image Quality of an Annular Array Photoacoustic Microscope

Suzuki Riku, Shintate Ryo, Ishii Takuro, Saijo Yoshifumi

Proceedings of Symposium on Ultrasonic Electronics　42　n/a　2021/10/25
Publisher: Institute for Ultrasonic Elecronics
DOI： 10.24492/use.42.0_3j4-2 　

ISSN：1348-8236

eISSN：2433-1910
1J3-2 High-speed Photoacoustic Microscopy Using MEMS Mirror with a Correction Method for Distortion Caused by the Mirror Scanning

Shintate Ryo, Kim Chulhong, Saijo Yoshifumi

Proceedings of Symposium on Ultrasonic Electronics　42　n/a　2021/10/25
Publisher: Institute for Ultrasonic Elecronics
DOI： 10.24492/use.42.0_1j3-2 　

ISSN：1348-8236

eISSN：2433-1910
アニュラアレイセンサへのDAS法応用による光音響顕微鏡像における被写界深度の改善

鈴木陸, 新楯諒, 石井琢郎, 西條芳文

電子情報通信学会技術研究報告(超音波)　121　(182)　23-27　2021/09
Publisher: (一社)電子情報通信学会
ISSN：0913-5685

eISSN：2432-6380

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末梢微小血管網の形態学的観察に,光音響イメージング技術が注目されている.本研究では,4チャンネルのアニュラアレイセンサを搭載した光音響イメージングシステムを用い,各チャンネルで得られた光音響信号にDelay-and-Sum(DAS)法を適用することによる最大振幅投影(MAP)画像の被写界深度への効果を評価することを目的とする.直径100μmのマイクロチューブと皮膚微小血管を対象に光音響イメージングを実施し,超音波センサから異なる深度における対象物の直径を計測した.その結果,探触子の幾何学的焦点から±1mmの範囲でDAS法の適用により対象物が最大で66.7%先鋭化され,DAS法の適用が光音響MAP画像の被写界深度の向上に有効である事を明らかにした.(著者抄録)
光を超音波で観る・超音波を光で観る光学・光音響ハイブリッド顕微鏡による細胞動態イメージング

新楯諒, 長岡亮, 石井琢郎, 西條芳文

超音波医学　48　(Suppl.)　S186-S186　2021/04
Publisher: (公社)日本超音波医学会
ISSN：1346-1176

eISSN：1881-9311
A histoanatomical study of the fiber bundle forming the 'Comma Sign,' a critical marker of the torn edge of the subscapularis tendon. International-journal Peer-reviewed

Ryuzo Arai, Yoshihiro Hagiwara, Yoshifumi Saijo, Shuichi Matsuda

Archives of orthopaedic and trauma surgery　2021/01/17

DOI： 10.1007/s00402-021-03775-6 　

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INTRODUCTION: The "Comma sign" is a well-known indicator of the subscapularis torn edge of the shoulder. We undertook a histoanatomical study of the fiber bundle forming Comma sign (FBCS) to determine why FBCS is maintained even in cuff tear cases. MATERIALS AND METHODS: Part 1: five tissue blocks including the supraspinatus tendon (SSP), rotator interval (RI), and subscapularis tendon (SSC) out of 5 cuff-intact cadavers were histologically observed in serial sections. Part 2: another tissue blocks of 6 cuff-intact cadavers were serially sectioned along the estimated FBCS direction based on the Part 1 findings. Additionally, 5 tissue blocks of cuff-torn cadavers including the three components, SSP, FBCS, and SSC, were serially sectioned along the apparent FBCS. In one slice clearly demonstrating FBCS fibers out of each section series, the components were measured of the sound speed and visualized through a scanning acoustic microscope (SAM). RESULTS: At the lateral portion, RI tissue with the joint capsule became thick and tightly surrounded SSP. Similarly, thicker RI tissue adhered to SSC from the superior and bursal side. More laterally, the borders of SSP/FBCS and FBCS/SSC were unclear with intermingled fibers. At the lateral most portion, RI tissue formed a fiber bundle, FBCS, extending from SSP to the bursal side of SSC. The sound speeds of SSP and SSC were significantly faster than FBCS in both cuff-intact and cuff-torn slices. In SAM images of cuff-torn specimens the FBCS borders were all unclear. CONCLUSIONS: As FBCS extends from the capsule beneath SSP and to the bursal surface of SSC, the FBCS connection to SSP and SSC is hardly lost, even though SSP or SSC detaches from the greater or lesser tubercle, respectively. Additionally, as degeneration make the elasticity difference gradual, the stress concentration at the borders may be diminished, leading to less breakage of FBCS.
High temporal resolution measurement of propagation pattern of myocardial stretching in left ventricle

Takafumi KUROKAWA, Hiroyuki NAKAJIMA, Shinichiro TAKAHASHI, Motonao TANAKA, Hiroshi KANAI, Yoshifumi SAIJO

Choonpa Igaku　48　(2)　73-80　2021
Publisher: Japan Society of Ultrasonics in Medicine
DOI： 10.3179/jjmu.jjmu.a.177 　

ISSN：1346-1176

eISSN：1881-9311
2E2-2 Optical/Photoacoustic Hybrid Microscopy with Deconvolution Processing for Visualizing Morphology and Composition of Cells

Shintate Ryo, Nagaoka Ryo, Ishii Takuro, Saijo Yoshifumi

Proceedings of Symposium on Ultrasonic Electronics　41　n/a　2020/11/25
Publisher: Institute for Ultrasonic Elecronics
DOI： 10.24492/use.41.0_2e2-2 　

ISSN：1348-8236

eISSN：2433-1910
ラット膝関節不動化モデルにおける低出力パルス超音波照射の関節拘縮抑制効果

板谷信行, 萩原嘉廣, 矢部裕, 金澤憲治, 小出将志, 関口拓也, 曽木靖仁, 西條芳文, 井樋栄二

超音波医学　47　(Suppl.)　S163-S163　2020/11
Publisher: (公社)日本超音波医学会
ISSN：1346-1176

eISSN：1881-9311
細胞の鮮明なイメージングを可能にする高分解能光音響顕微鏡の開発

新楯諒, 長岡亮, 小林和人, 西條芳文

超音波医学　47　(Suppl.)　S189-S189　2020/11
Publisher: (公社)日本超音波医学会
ISSN：1346-1176

eISSN：1881-9311
半球型アレイトランスデューサと4方向傾斜レーザ照射による3次元光音響イメージング

森野太介, 新楯諒, 林瑛己, 長岡亮, 吉澤晋, 梅村晋一郎, 西條芳文

超音波医学　47　(Suppl.)　S524-S524　2020/11
Publisher: (公社)日本超音波医学会
ISSN：1346-1176

eISSN：1881-9311
コンケーブアレイプローブを用いた光音響イメージング

高橋爽, 西條芳文, 新楯諒

超音波医学　47　(Suppl.)　S525-S525　2020/11
Publisher: (公社)日本超音波医学会
ISSN：1346-1176

eISSN：1881-9311
光音響顕微鏡を用いた皮下微小血管の検討

平塚竜基, 高橋爽, 菅野尚哉, 新楯諒, 梅村晋一郎, 西條芳文

超音波医学　47　(Suppl.)　S525-S525　2020/11
Publisher: (公社)日本超音波医学会
ISSN：1346-1176

eISSN：1881-9311
The hybrid optical and photoacoustic microscopy: A novel system to image morphological and photoacoustic characteristics of cells

Ryo Shintate, Ryo Nagaoka, Takuro Ishii, Yoshifumi Saijo

IEEE International Ultrasonics Symposium, IUS　2020-September　2020/09/07

DOI： 10.1109/IUS46767.2020.9251548 　

ISSN：1948-5719

eISSN：1948-5727

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© 2020 IEEE. Optical resolution photoacoustic microscopy (OR-PAM) can achieve an optical-dependent high lateral resolution (<1 µm) and visualize photoacoustic (PA) property at single-cell level. The spatial resolvability of the PA imaging is expected to precisely characterize biological activities of cells such as their interactions with drugs and contrast agents by comparing the acquired PA characteristics with the cell's morphology. However, since the conventional OR-PAM systems only visualize objects that generate PA signals, it was difficult to acquire a PA image and an optical morphological image simultaneously. Here, we report a novel system of the hybrid optical / PA microscopy that can acquire morphological and PA characteristics of cells at the same time. The performance of the developed system was validated by measuring a USAF1951 target and bovine red blood cells.
アニュラアレイトランスデューサを用いた音響分解能光音響顕微鏡によるイメージング

平塚竜基, 高橋爽, 佐藤滉太, 新楯諒, 梅村晋一郎, 石井琢郎, 西條芳文

電子情報通信学会技術研究報告(超音波)　120　(174)　73-77　2020/09
Publisher: (一社)電子情報通信学会
ISSN：0913-5685

eISSN：2432-6380

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光音響イメージングとは光と超音波を組み合わせた非侵襲的なイメージング手法であり、高分解能・高深達度の性質を持つため近年医療応用が期待されている。より正確に3次元的イメージングを行うには、被写界深度を広げる必要があり、被写界深度を広げる手法を考えなければならない。本目的を達成するために、半球型アレイトランスデューサを用いて信号を取得し、ビームフォーミングを行うことによって被写界深度の検討を行った。(著者抄録)
コンケーブアレイプローブを用いた光音響イメージングにおける単方向・多方向送受信の比較検討

高橋爽, 新楯諒, 川口航汰, 菅野尚哉, 佐藤滉太, 石井琢郎, 西條芳文

電子情報通信学会技術研究報告(超音波)　120　(174)　78-82　2020/09
Publisher: (一社)電子情報通信学会
ISSN：0913-5685

eISSN：2432-6380

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光音響イメージングとは光と超音波を組み合わせた非侵襲のイメージング手法であり、通常の超音波イメージングと比較するとより選択的なイメージングが可能であるという特徴を持つため、今後は微小血管の可視化等の医療分野での応用が期待されている。本研究ではより高精度な光音響イメージングの実現に向けて、光の照射方法や光音響波の受信方法などの測定条件を変えた実験を複数回行い、結果の比較検討を行った。(著者抄録)
乳癌患者における化学療法による心毒性が原因の局所左室変形に関する経時的変化(Longitudinal Change of Regional Left Ventricular Deformation by Chemotherapy-induced Cardiotoxicity in Patients with Breast Cancer)

藤原淳子, 後岡広太郎, 杉村宏一郎, 照井洋輔, 佐藤遥, 多田寛, 大田英揮, 船水康陽, 三木俊, 西條芳文, 高瀬圭, 石田孝宜, 下川宏明

日本循環器学会学術集会抄録集　84回　OJ12-6　2020/07
Publisher: (一社)日本循環器学会
Development of optical resolution photoacoustic microscopy with sub-micron lateral resolution for visualization of cells and their structures Peer-reviewed

Ryo Shintate, Taisuke Morino, Kota Kawaguchi, Ryo Nagaoka, Kazuto Kobayashi, Makoto Kanzaki, Yoshifumi Saijo

Japanese Journal of Applied Physics　59　2020/07/01

DOI： 10.35848/1347-4065/ab840e 　

ISSN：0021-4922

eISSN：1347-4065

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© 2020 The Japan Society of Applied Physics. Photoacoustic (PA) imaging is a hybrid imaging technique with light-dependent contrast and ultrasound-dependent depth. In previous studies, the interest of PA imaging was mainly clinical research. However, in recent years, PA imaging that targets cells also has attracted attention. Cells are the smallest unit in our body, and cell abnormalities cause various diseases. Therefore, PA imaging of cells is important for elucidating the relationship between diseases and PA properties and linking the results to the clinical application of PA imaging. For PA imaging of cells and its internal structures, sub-micron lateral resolution is required. In this study, we have developed an optical resolution photoacoustic microscopy (OR-PAM) system using a high NA objective lens and a single-mode fiber to achieve sub-micron lateral resolution. With the OR-PAM, it was confirmed that the lateral resolution was better than 700 nm, and the characteristic shapes of red blood cells and melanoma cells could be visualized.
Visualization of Shoulder Ligaments Motion by Ultrasound Speckle Tracking Method. International-journal Peer-reviewed

Norma Hermawan, Mizuki Fujiwara, Yoshihiro Hagiwara, Yoshifumi Saijo

Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual International Conference　2020　2084-2087　2020/07

DOI： 10.1109/EMBC44109.2020.9176374 　

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There is no unified consensus on the pathophysiology of adhesive capsulitis which is also called as frozen shoulder. Some studies have suggested that coracohumeral ligament (CHL) played an important role in adhesive capsulitis. These studies showed relation between disease prevalence and CHL thickness by means of ultrasound or MRI. Other possible etiology of the disease is the adhesion of shoulder ligament with each other. In the present study, shoulder ligaments motion is visualized with velocity vector by speckle tracking and temporal outlier removal algorithm to process ultrasound movie during forced movement of shoulder joint. The measurement with a typical subject has demonstrated an improvement of velocity vector deviation of up to 43% by the proposed outlier removal technique.
2P5-14 Visualization of cell structure by optical resolution photoacoustic microscopy with sub-micron lateral resolution

Shintate Ryo, Nagaoka Ryo, Kobayashi Kazuto, Saijo Yoshifumi

Proceedings of Symposium on Ultrasonic Electronics　40　n/a　2019/11/25
Publisher: Institute for Ultrasonic Elecronics
DOI： 10.24492/use.40.0_2p5-14 　

ISSN：1348-8236

eISSN：2433-1910
Role of intra-ventricular vortex in left ventricular ejection elucidated by echo-dynamography Peer-reviewed

Motonao Tanaka, Tsuguya Sakamoto, Yoshifumi Saijo, Yoshiaki Katahira, Shigeo Sugawara, Hiroyuki Nakajima, Takafumi Kurokawa, Hiroshi Kanai

Journal of Medical Ultrasonics　46　(4)　413-423　2019/10/01

DOI： 10.1007/s10396-019-00943-5 　

ISSN：1346-4523

eISSN：1613-2254

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Purpose: From the correlation between the blood flow dynamics and wall dynamics in the left ventriocle (LV) analyzed using echo-dynamography, the ejection mechanisms and role of the intra-ventricular vortex in the LV were elucidated in detail during the pre-ejection transitional period (pre-ETP), the very short period preceding LV ejection. Methods: The study included 10 healthy volunteers. Flow structure was analyzed using echo-dynamography, and LV wall dynamics were measured using both high-frame-rate two-dimensional echocardiography and a phase difference tracking method we developed. Results: A large accelerated vortex occurred at the central basal area of the LV during this period. The main flow axis velocity line of the LV showed a linearly increasing pattern. The slope of the velocity pattern reflected the deformity of the flow route induced by LV contraction during the pre-ETP. The centrifugal force of the vortex at its junction with the main outflow created a stepwise increase of about 50% of the ejection velocity. Conclusion: Ejection of blood from the LV was accomplished by the extruding action of the ventricular wall and the centrifugal force of the accelerated vortex during this period. During ejection, acceralated outflow was considered to create a spiral flow in the aorta with help from the spherical structure of the Valsalva sinus.
Biomechanics of C2C12 Cells Observed with Cellular Resolution Scanning Acoustic Microscope Combined with Optical Microscope. International-journal Peer-reviewed

Ryo Hirano, Makoto Kanzaki, Mototaka Arakawa, Norma Hermawan, Kazuto Kobayashi, Yoshifumi Saijo

Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference　2019　4828-4831　2019/07

DOI： 10.1109/EMBC.2019.8857008 　

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Biomechanics of the cell indicates the inner structure and viability of the cell. Mechanical properties are represented by acoustic properties such as speed of sound (SOS) or acoustic impedance. In the present study, cellular resolution scanning acoustic microscope combined with optical microscope (OptSAM) is developed to observe the change of mechanical properties in cell differentiation. Main part of the OptSAM was consisted of 350 MHz ultrasound transducer mechanically scanned by a piezo-actuator. Thickness, SOS, acoustic impedance, density and elastic bulk modulus of the cell were deduced by the ultrasound responses in both time domain and frequency domain. C2C12 cell changing its form from myoblast to myotube was observed by OptSAM. The value of bulk modulus slightly increased in response to differentiation process. OptSAM non-invasively provides important information on biomechanics of cells without contact or staining.
Multidirectional reception of photoacoustic signals for higher resolution imaging Peer-reviewed

Kanta Sato, Ryo Shintate, Mitsuhiro Fujiwara, Yoshifumi Saijo

Japanese Journal of Applied Physics　58　(SG)　2019

DOI： 10.7567/1347-4065/ab19b7 　

ISSN：0021-4922

eISSN：1347-4065

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© 2019 The Japan Society of Applied Physics. The imaging of microvasculature of the synovial membrane is important for the early detection of rheumatoid arthritis (RA). Photoacoustic (PA) imaging is an imaging modality that is compatible with the advantages of high spatial resolution in optical imaging and high penetration depth in ultrasound imaging. Linear probes are mainly used in clinical PA imaging. However, it is difficult for linear probes to acquire the PA signal completely from a point sound source in tissue because the area for signal reception is limited. In the present study, high resolution PA imaging as proposed by receiving the PA signals with linear probes placed at multiple angles around the imaging target to generate a compound PA image. The proposed method was compared to the conventional method with a single linear probe by computer simulation and measurement. The proposed method showed significant improvement of resolution and contrast.
Blood flow imaging using singular value decomposition filter during high-intensity focused ultrasound exposure

Hayato Ikeda, Shin Yoshizawa, Moe Maeda, Shin Ichiro Umemura, Yoshifumi Saijo

Japanese Journal of Applied Physics　58　2019/01/01

DOI： 10.7567/1347-4065/ab1a2e 　

ISSN：0021-4922

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© 2019 The Japan Society of Applied Physics. High-intensity focused ultrasound (HIFU) is a minimally invasive treatment modality to induce thermal coagulation. In clinical cases, noninvasive blood flow occlusion was successfully achieved by HIFU exposure. However, it is difficult to monitor the blood flow during HIFU exposure due to the interference of HIFU noise with RF echo signals. In this study, we proposed a novel filtering method for monitoring blood flow during HIFU exposure by combining an singular value decomposition (SVD) filter with the HIFU noise reduction method. The HIFU noise was reducted by subtracting the RF signals of passive imaging from the RF signals of active imaging while keeping the tissue and blood flow signals intact. After that, the blood flow signals were identified by employing the SVD filter, on the basis of the spatiotemporal characteristics and amplitudes of these signals. The results imply that the proposed filtering method is useful for monitoring of blood flow during HIFU exposure.
Correction of phase rotation in pulse spectrum method for scanning acoustic microscopy and its application to measurements of cells Peer-reviewed

Nagaoka R, Kobayashi K, Arakawa M, Hasegawa H, Saijo Y

Ultrasonics　99　2019

DOI： 10.1016/j.ultras.2019.105949 　
Medical imaging: Acoustic microscopy (AM)

穂積直裕, 西條芳文

応用物理　87　(12)　932‐936-936　2018/12/10
Publisher: 応用物理学会
DOI： 10.11470/oubutsu.87.12_932 　

ISSN：0369-8009

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Biological acoustic microscopy makes it possible to acquire quantitative acoustic parameters such as sound speed and acoustic impedance that can be correlated to hardness of the tissue. As it does not need the staining process that is normally required in optical observation, a non-invasive observation of living tissues and cells can be realized. Its outline and some examples of observations will be described.
Optical Resolution Photoacoustic Microscopy with Fast Laser Scanning and Fixed Photoacoustic Detector∗ Peer-reviewed

Kodai Ishikawa, Ryo Shintate, Ryo Nagaoka, Yoshifumi Saijo

Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS　2018-July　4800-4803　2018/10/26

DOI： 10.1109/EMBC.2018.8513104 　

ISSN：1557-170X

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© 2018 IEEE. Photoacoustic (PA) imaging is rapidly progressing imaging modality in which very short pulsed laser causes thermal expansion to generate PA signal. In previous PA microscope systems, relatively long time was required for image acquisition because they required mechanical scan of the PA transducer. The objective of the present study is to develop fast laser scanning optical resolution photoacoustic microscopy (OR-PAM) with fixed PA signal detector to realize very high frame rate PA imaging. Q-switched Nd:YAG laser with the wavelength of 532 nm, pulse width of 5.5 ns and pulse repetition rate of up to 50 kHz was equipped in the system. Low frequency PA detector was comprised of a glass prism configuring acoustic focusing and a polymethyl methacrylate (PMMA) prism with 5 MHz PZT (lead zirconate titanate) transducer. High frequency PA detector was comprised of the same glass prism and a glass prism with ZnO (zinc oxide) thin film transducer. Galvano scanner operating in the air was controlled by a microcomputer to scan laser beam. PA signal was detected with the fixed PA detector thus realized the frame rate of 5 fps for C-mode equivalent to 500 fps for B-mode. The lateral resolution of the low frequency system was found to be 11.6 μm and the blood vessel on the surface of cod roe was clearly visualized. The system may be applicable for imaging blood flow and vascular dynamics of micro vessel.
A theoretical model of laser heating carbon nanotubes. Peer-reviewed

Siregar S, Oktamuliani S, Saijo Y

Nanomaterials　8　580　2018/08

DOI： 10.3390/nano8080580 　
Left Ventricular Blood Flow Dynamics In Aortic Stenosis Before And After Aortic Valve Replacement. International-journal Peer-reviewed

Tadanori Minagawa, Yoshifumi Saijo, Sri Oktamuliani, Takafumi Kurokawa, Hiroyuki Nakajima, Kaoru Hasegawa, Takayuki Matsuoka, Takuya Shimizu, Makoto Miura, Takahiro Ohara, Shunsuke Kawamoto

Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference　2018　3177-3180　2018/07
Publisher: IEEE
DOI： 10.1109/EMBC.2018.8512954 　

ISSN：1557-170X

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Surgical intervention for aortic valve stenosis (AS) has been established; however its diagnosis based on echocardiographic assessment is still limited by aortic valvular velocity, aortic valvular pressure gradients, and color Doppler imaging. Echo-dynamography (EDG) is a method to determine intracardiac flow dynamics, such as two-dimensional blood flow velocity, vortex, and dynamic pressure. These flow dynamics may be influenced by left ventricular (LV) wall motion and the resistance in LV outflow caused by AS. The objective of the present study was to assess the changes and differences in LV vortices and vorticity before and after AS surgery. Five patients who underwent aortic valve replacement surgery for AS and five control patients were included. Besides routine echocardiographic measurement, EDG was applied to determine the two-dimensional blood flow vector and vorticity. The LV vortex flow in the isovolumetric contraction phase had multiple formations in preoperative cases. The clockwise vortex was found in all cases postoperatively; the vortex formation showed no significant difference between postoperative and normal control groups. EDG may serve important information on LV flow dynamics, non-invasively.
Development of new human thermal model based on blood flow rate measurements under different temperature conditions Peer-reviewed

T Goto, D Terayama, H Sakamoto, T Hayase, Y Saijo, R Sugawara, Z Niu

15th Conference of the International Society of Indoor Air Quality and Climate (Indoor Air 2018)　2018/07
EFFECTS OF LOW-INTENSITY PULSED ULTRASOUND FOR PREVENTING JOINT STIFFNESS IN IMMOBILIZED KNEE MODEL IN RATS Peer-reviewed

Itaya, Nobuyuki, Yabe, Yutake, Hagiwara, Yoshihiro, Kanazawa, Kenji, Koide, Masashi, Sekiguchi, Takuya, Yoshida, Shinichirou, Sogi, Yasuhito, Yano, Toshihisa, Tsuchiya, Masahiro, Saijo, Yoshifumi, Itoi, Eiji

ULTRASOUND IN MEDICINE AND BIOLOGY　44　(6)　1244-1256　2018/06
Publisher: ELSEVIER SCIENCE INC
DOI： 10.1016/j.ultrasmedbio.2018.02.002 　

ISSN：0301-5629

eISSN：1879-291X

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The purpose of this study was to examine the effect of low-intensity pulsed ultrasound (LIPUS) in preventing joint stiffness. Unilateral knee joints were immobilized in two groups of rats (n = 6/period/getup). Under general anesthesia, the immobilized knee joints were exposed to LIPUS for 20 min/d, 5 d/wk, using an existing LIPUS device (LIPUS group, 1.5-MHz frequency, 1.0-kHz repetition cycle, 200-mu s burst width and 30-mW/cm(2) power output) until endpoints (2, 4 or 6 wk). In the control group, general anesthesia alone was administered in the same manner as in the other group. The variables compared between the groups included joint angles; histologic, histomorphometric and immunohistochemical analyses; quantitative reverse transcription polymerase chain reactions; and tissue elasticity. LIPUS had a preventive effect on joint stiffness, resulting in decreased adhesion, fibrosis and inflammation and hypoxic response after joint immobilization. (C) 2018 World Federation for Ultrasound in Medicine & Biology. All rights reserved.
Visualization of murine lymph vessels using photoacoustic imaging with contrast agents Peer-reviewed

Ryo Nagaoka, Takuya Tabata, Shin Yoshizawa, Shin-ichiro Umemura, Yoshifumi Saijo

Photoacoustics　9　39-48　2018/03/01
Publisher: Elsevier GmbH
DOI： 10.1016/j.pacs.2018.01.001 　

ISSN：2213-5979

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Metastasis frequently occurs even in the early stage of breast cancer. This research studied the feasibility of using photoacoustic (PA) imaging for identifying metastasis in the lymph vessels of mice. The photoacoustic efficiency of various contrast agents was investigated, and the influence of scattered light was evaluated by using a lymph vessel phantom. The lymph vessels of mice were then visualized using the selected contrast agents: indocyanine green (ICG) and gold nanorods (AuNR). The attenuation of the PA imaging was −1.90 dB/mm, whereas that of the fluorescence imaging was −4.45 dB/mm. The results indicate the potential of identifying sentinel lymph nodes by using PA imaging with these contrast agents.
A method for the design of ultrasonic devices for scanning acoustic microscopy using impulsive signals Peer-reviewed

Mototaka Arakawa, Hiroshi Kanai, Kazuo Ishikawa, Ryo Nagaoka, Kazuto Kobayashi, Yoshifumi Saijo

Ultrasonics　84　172-179　2018/03/01
Publisher: Elsevier B.V.
DOI： 10.1016/j.ultras.2017.10.023 　

ISSN：0041-624X

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Scanning acoustic microscopy (SAM) using impulsive signals is useful for characterization of biological tissues and cells. The operating center frequency of an ultrasonic device strongly depends on the performance characteristics of the device if the measurement is conducted by using impulsive signals. In this paper, a method for the design of ultrasonic devices for SAM using impulsive signals was developed. A new plane-wave model was introduced to calculate frequency characteristics of loss of ultrasonic devices by taking into account the conversion loss at the ultrasonic transducer, the transmission loss at the acoustic anti-reflection coating, and the propagation loss in the couplant. Ultrasonic devices were fabricated with a ZnO ultrasonic transducer using two acoustic lenses with aperture radii of 1.0 mm and 0.5 mm, respectively. The frequencies at which measured losses became minima corresponded to the calculation results by the plane-wave model. This numerical calculation method is useful for designing ultrasonic devices for acoustic microscopy using impulsive signals.
Singular value decomposition of received ultrasound signal to separate tissue, blood flow, and cavitation signals. Peer-reviewed

Ikeda H, Nagaoka R, Lafond M, Yoshizawa S, Iwasaki R, Maeda M, Umemura SI, Saijo Y

Jpn J Appl Phys　57　07LF04　2018

DOI： 10.7567/JJAP.57.07LF04 　
Deduction of two-dimensional blood flow vector by dual angle diverging waves from a cardiac sector probe. Peer-reviewed

Maeda M, Nagaoka R, Ikeda H, Yaegashi S, Saijo Y

Jpn J Appl Phys　57　07LF02　2018

DOI： 10.7567/JJAP.57.07LF02 　
Basic study of improvement of axial resolution and suppression of time side lobe by phase-corrected Wiener filtering in photoacoustic tomography. Peer-reviewed

Nagaoka R, Yoshizawa S, Umemura SI, Saijo Y

Jpn J Appl Phys　57　07LD11　2018

DOI： 10.7567/JJAP.57.07LD11 　
Robust analysis method for acoustic properties of biological specimens measured by acoustic microscopy. Peer-reviewed

Arakawa M, Mori S, Kanai H, Nagaoka R, Horie M, Kobayashi K, Saijo Y

Jpn J Appl Phys　57　(7)　07LB07　2018

DOI： 10.7567/JJAP.57. 　

ISSN：0021-4922

eISSN：1347-4065

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We proposed a robust analysis method for the acoustic properties of biological specimens measured by acoustic microscopy. Reflected pulse signals from the substrate and specimen were converted into frequency domains to obtain sound speed and thickness. To obtain the average acoustic properties of the specimen, parabolic approximation was performed to determine the frequency at which the amplitude of the normalized spectrum became maximum or minimum, considering the sound speed and thickness of the specimens and the operating frequency of the ultrasonic device used. The proposed method was demonstrated for a specimen of malignant melanoma of the skin by using acoustic microscopy attaching a concave transducer with a center frequency of 80 MHz. The variations in sound speed and thickness analyzed by the proposed method were markedly smaller than those analyzed by the method based on an autoregressive model. The proposed method is useful for the analysis of the acoustic properties of bilogical tissues or cells.
Non local means denoising in photoacoustic imaging. Peer-reviewed

Siregar S, Nagaoka R, Ul Haq I, Saijo Y

Jpn J Appl Phys　57　07L B06　2018

DOI： 10.7567/JJAP.57.07LB06 　
Visualization of the microcirculation in micro vasculatures by photoacoustic tomography with high frequency spherical array transducer Peer-reviewed

Ryo Nagaoka, Takuya Tabata, Ryo Takagi, Shin Yoshizawa, Shin-Ichiro Umemura, Yoshifumi Saijo

IEEE International Ultrasonics Symposium, IUS　2017/10/31
Publisher: IEEE Computer Society
DOI： 10.1109/ULTSYM.2017.8092091 　

ISSN：1948-5727 1948-5719

eISSN：1948-5727

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A spatial resolution of photoacoustic tomography (PAT) has been limited by the receive frequency significantly lower than that of photoacoustic microscopy. In the present study, an in vivo microcirculation is visualized by a PAT system by using a newly developed spherical array transducer with a center frequency of 10 MHz. Additionally, we propose a novel reconstruction method suppressing the side lobe level with Wiener filtering.
Development of Real-Time 3-D Photoacoustic Imaging System Employing Spherically Curved Array Transducer Peer-reviewed

Ryo Nagaoka, Takuya Tabata, Ryo Takagi, Shin Yoshizawa, Shin-Ichiro Umemura, Yoshifumi Saijo

IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL　64　(8)　1223-1233　2017/08
Publisher: IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
DOI： 10.1109/TUFFC.2017.2718030 　

ISSN：0885-3010

eISSN：1525-8955

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Photoacoustic (PA) imaging is a promising imaging modality to visualize specific living tissues based on the light absorption coefficients without dyeing. In this paper, a real-time PA imaging system with a tunable laser was newly developed with an originally designed spherically curved array transducer. Five different series of experiments were conducted to validate the PA measurement system. The peak frequency of the transducer response was 17.7 MHz, and a volume-imaging rate of 3-D volume imaging was 10-20 volumes per second. The spatial resolution of imaging was 90-105 mu m along both the axial and lateral directions. The developed imaging system could measure a difference on an absorption coefficient of gold nanorods. Additionally, the PA imaging could visualize the in vivo microvasculatures of a human hand. This PA imaging system with higher spatial-temporal resolution and the tunable laser further should enhance our understanding of not only basic properties of the photo acoustics but also clinical applications.
Sparse-representation-based denoising of photoacoustic images Peer-reviewed

Israr Ul Haq, Ryo Nagaoka, Syahril Siregar, Yoshifumi Saijo

Biomedical Physics and Engineering Express　3　(4)　045014　2017/07/10
Publisher: Institute of Physics Publishing
DOI： 10.1088/2057-1976/aa7a44 　

ISSN：2057-1976

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Optical resolution photoacoustic microscopy (OR-PAM) is an emerging hybrid technology that combines optical contrast and acoustic resolution. The quality of photoacoustic (PA) images is degraded due to different parameters such as frequency, the diameter of the transducer or external noise induced from the laser. The diameter of the transducer is proportional to its near field to focus or unfocus the transducer, which affects the image quality, so reconstruction and denoising of photoacoustic images is an important issue inmedical imaging, especially when it comes to diagnosing diseases at an early stage. Visualization of different structures in the PA images requires filtering to suppress noise. This paper investigates the use of K-means singular value decomposition (K-SVD) to eliminate noise and enhance the effect of vasculature in the PA images. The algorithm is tested on PA images of blood-filled tubes of different diameters and in vivo mouse ear images acquired usingOR-PAMimaging. The results reveal a better denoising capability of PA images when compared with standard Wiener andwavelet-based filtering.
Graduate School of Biomedical Engineering at Tohoku University The history of foundation and recent education program on global entrepreneur of medical devices

Saijo Yoshifumi

Transactions of Japanese Society for Medical and Biological Engineering　55　(3)　192-192　2017
Publisher: Japanese Society for Medical and Biological Engineering
DOI： 10.11239/jsmbe.55Annual.192 　

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Graduate School of Biomedical Engineering was founded in 2008 as Japan's first independent graduate school specialized in biomedical engineering. Tohoku
Evaluation of blood flow dynamics in healthy and myocardial infarction hearts using Echodynamography Peer-reviewed

Sri Oktamuliana, Yoshifumi Saijo, Kaoru Hasegawa

Proceedings of Meetings on Acoustics　32　(1)　2017
Publisher: Acoustical Society of America
DOI： 10.1121/2.0000716 　

ISSN：1939-800X

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Blood flow dynamics were analyzed in healthy and myocardial infarction (MI) subjects using Echodynamography (EDG). EDG visualizes two-dimensional (2D) distribution of blood flow vector in the heart applying the theories of fluid dynamics to color Doppler echocardiography. The principle concept of EDG is that non-turbulent blood flow is described as the combination of base flow and vortex flow. The vortex flow is considered as a flow on a plane so that classical "stream function" is applied to obtain blood flow vector. The base flow is defined as the flow without vortex formation on the plane. Newly proposed "flow function" considers blood flow to and from other plane and the vector of the base flow is obtained with the flow function. Color Doppler data of heart apical three-chamber view were recorded by a commercially available medical ultrasound equipment. Blood flow distribution was different in healthy and MI subjects. In a healthy subject, vortex flow was observed as a whole blood flow in along the central flow area distributed to the base of the heart, and in the myocardial infarction the entire blood flow region the massive vortex flow was observed mainly at the apical part even in the ejection period.
Differentiation of Vein and Lymphatic Vessel by Photoacoustic Imaging System with Parabolic Array Transducer and Tunable Laser Peer-reviewed

Takuya Tabata, Ryo Nagaoka, ShinIchiro Umemura, Yoshifumi Saijo, Shin Yoshizawa

2017 IEEE INTERNATIONAL ULTRASONICS SYMPOSIUM (IUS)　2017
Publisher: IEEE
ISSN：1948-5719

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Recently, much attention is being paid to lymphatic circulation because intralymphatic immunotherapy and chemotherapy achieved significant clinical benefits. However, conventional ultrasound or photoacoustic (PA) imaging is hard to visualize lymphatic vessels. In the present study, real-time threedimensional PA imaging system consisted of 256-ch parabolic array transducer with the central frequency of 10 MHz and tunable laser with the wavelength of 400-2100 nm was developed. Photoacoustic contrast agents such indocyanine green (ICG) or gold nanorods (AuNRs) were administrated to the lymphatic vessels of the ICR mouse. The vein was visualized at the wavelength of 490-600 nm without contrast agents. The lymphatic vessel was visualized at 670-770 nm with ICG and at 790-890 nm with AuNRs. The system is clinically applicable for detection of small lymphatic vessels to confirm successful drug delivery during intralymphatic chemotherapy.
Assessment of Inter-Expert Variability and of an Automated Segmentation Method of 40 and 60 MHz IVUS Images of Coronary Arteries Peer-reviewed

Francois Destrempes, Marie-Helene Roy Cardinal, Yoshifumi Saijo, Gerard Finet, Jean-Claude Tardif, Guy Cloutier

PLOS ONE　12　(1)　e0168332　2017/01
Publisher: PUBLIC LIBRARY SCIENCE
DOI： 10.1371/journal.pone.0168332 　

ISSN：1932-6203

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The objectives were to compare the performance of a segmentation algorithm, based on the minimization of an uncertainty function, to delineate contours of external elastic membrane and lumen of human coronary arteries imaged with 40 and 60 MHz IVUS, and to use values of this function to delineate portions of contours with highest uncertainty. For 8 patients, 40 and 60 MHz IVUS coronary data acquired pre- and post-interventions were used, for a total of 68,516 images. Manual segmentations of contours (on 2312 images) performed by experts at three core laboratories were the gold-standards. Inter-expert variability was highest on contour points with largest values of the uncertainty function (p < 0.001). Inter-expert variability was lower at 60 than 40 MHz for external elastic membrane (p = 0.013) and lumen (p = 0.024). Average differences in plaque (and atheroma) burden between algorithmic contours and experts' contours were within inter-expert variability (p < 0.001).
Measurement of blood flow rates under three different temperatures, and development of a new human thermal model

Daiki Terayama, Hiroto Sakamoto, Toshiyuki Hayase, Yoshifumi Saijo, Tomonobu Goto

The 5th International Conference on Human-Environment System　2016/10/29
Changes of masseter muscle in a rat unilateral occlusal model assessed by photoacoustic imaging system

Kouki Hatori, Yoshifumi Saijo, Masahiro Iikubo, Yoshihiro Hagiwara, Kuniyuki Izumita, Yukihiro Naganuma, Keiichi Sasaki

The Journal of the Acoustical Society of America　140　(4)　2980-2980　2016/10
Publisher: Acoustical Society of America (ASA)
DOI： 10.1121/1.4969225 　

ISSN：0001-4966
経皮的肺動脈形成術治療が施行された慢性血栓塞栓性肺高血圧患者における心エコーによる右室機能評価法の検討

藤原淳子, 船水康陽, 三木俊, 建部俊介, 青木竜男, 大田英揮, 杉村宏一郎, 坂田泰彦, 西條芳文, 下川宏明

超音波医学　43　(4)　603-603　2016/07
Publisher: (公社)日本超音波医学会
ISSN：1346-1176

eISSN：1881-9311
Differences between cardiac memory T wave changes after idiopathic left ventricular tachycardia and ischemic T wave inversion induced by acute coronary syndrome Peer-reviewed

Takashi Nakagawa, Tetsuo Yagi, Akihiko Ishida, Yoshiaki Mibiki, Yoshihiro Yamashina, Hirokazu Sato, Eiji Sato, Juri Komatsu, Yoshifumi Saijo

Journal of Electrocardiology　49　(4)　596-602　2016/07/01
Publisher: Churchill Livingstone Inc.
DOI： 10.1016/j.jelectrocard.2016.04.001 　

ISSN：1532-8430 0022-0736

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Background Cardiac memory (CM) after idiopathic left ventricular tachycardia (ILVT) mimics ischemic T wave inversion (TWI) induced by acute coronary syndrome (ACS). We aimed to establish electrocardiography criteria for differentiating the CM from ischemic TWI. Methods and results We evaluated 16 ILVT and 48 ACS patients. We identified TWI after ILVT in 9/16 patients (CM group), typically in leads II, III, aVF, aVR, and V4–6. The characteristics of CM were similar to TWI induced by ACS involving right coronary artery, but the CM group had more TWI in V4 and shorter QTc. The criteria of (1) positive T in aVL, (2) negative or isoelectric T in II, and (3) negative T in V4–6 or (4) QTc &lt 430 ms were 100% sensitive and 96% specific for the CM group. Conclusion CM after ILVT can be differentiated in most cases from ischemic TWI by the distribution of TWI and the QTc.
Monitoring of high-intensity focused ultrasound treatment by shear wave elastography induced by two-dimensional-array therapeutic transducer Peer-reviewed

Ryosuke Iwasaki, Ryo Takagi, Ryo Nagaoka, Hayato Jimbo, Shin Yoshizawa, Yoshifumi Saijo, Shin-ichiro Umemura

JAPANESE JOURNAL OF APPLIED PHYSICS　55　(7)　07KF05　2016/07
Publisher: IOP PUBLISHING LTD
DOI： 10.7567/JJAP.55.07KF05 　

ISSN：0021-4922

eISSN：1347-4065

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Shear wave elastography (SWE) is expected to be a noninvasive monitoring method of high-intensity focused ultrasound (HIFU) treatment. However, conventional SWE techniques encounter difficulty in inducing shear waves with adequate displacements in deep tissue. To observe tissue coagulation at the HIFU focal depth via SWE, in this study, we propose using a two-dimensional-array therapeutic transducer for not only HIFU exposure but also creating shear sources. The results show that the reconstructed shear wave velocity maps detected the coagulated regions as the area of increased propagation velocity even in deep tissue. This suggests that "HIFU-push" shear elastography is a promising solution for the purpose of coagulation monitoring in deep tissue, because push beams irradiated by the HIFU transducer can naturally reach as deep as the tissue to be coagulated by the same transducer. (C) 2016 The Japan Society of Applied Physics
たこつぼ型心筋症の部位別頻度と回復期における心形態変化の特徴

佐々木絵里奈, 伊藤記彦, 稲葉綾香, 長尾祥史, 小泉真澄, 遠藤洋一, 藤原淳子, 船水康陽, 三木俊, 青木竜男, 西條芳文

超音波検査技術　41　(Suppl.)　S136-S136　2016/06
Publisher: (一社)日本超音波検査学会
ISSN：1881-4506

eISSN：1881-4514
経胸壁心エコー検査によるLibman-Sacks心内膜炎評価の検討

小泉真澄, 藤原淳子, 遠藤洋一, 船水康陽, 三木俊, 青木竜男, 西條芳文

超音波検査技術　41　(Suppl.)　S139-S139　2016/06
Publisher: (一社)日本超音波検査学会
ISSN：1881-4506

eISSN：1881-4514
心臓移植後早期に拒絶反応を呈した1症例

遠藤洋一, 青木, 竜男, 藤原, 淳子, 船水, 康陽, 三木, 俊, 西條, 西條芳文, 杉村, 宏一郎, 秋山, 正年, 川本, 俊輔, 齋木, 佳克, 下川宏明

超音波検査技術　41　(Suppl.)　S151-S151　2016/06
Publisher: None
DOI： 10.11272/jssabst.41.0_S151_2 　

ISSN：1881-4506

eISSN：1881-4514
Eisenmenger Syndromeに肺移植と心内修復術を施行した一例

伊藤記彦, 青木竜男, 船水康陽, 藤原淳子, 三木俊, 西條芳文, 建部俊介, 杉村宏一郎, 岡田克典, 下川宏明

超音波医学　43　(Suppl.)　S585-S585　2016/04
Publisher: (公社)日本超音波医学会
ISSN：1346-1176

eISSN：1881-9311
Activities of Japan Society of Medical Ultrasonics in Miyagi Prefecture after Great East Japan Earthquake

SAIJO Yoshifumi

Choonpa Igaku　43　(1)　55-59　2016
Publisher: The Japan Society of Ultrasonics in Medicine
DOI： 10.3179/jjmu.JJMU.R.71 　

ISSN：1346-1176

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The activities of the Japan Society of Medical Ultrasonics in Miyagi Prefecture after the Great East Japan Earthquake are described.
Two-dimensional Blood Flow Vector and Wall Shear Stress of Carotid Artery Obtained with Dual-angle Doppler Method Peer-reviewed

Osamu Akagawa, Kosuke Fukazu, Ryo Nagaoka, Yoshifumi Saijo

2016 IEEE INTERNATIONAL ULTRASONICS SYMPOSIUM (IUS)　2016
Publisher: IEEE
ISSN：1948-5719

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Biomechanical assessment of atherosclerosis has been mainly studied by tissue characterization and elasticity measurement of arterial wall in biomedical ultrasound. On the other hand, fluid shear stress on the artery is also known as an important factor to change vascular endothelium properties leading to atherosclerosis. Ultrasound is a suitable imaging modality to measure blood flow with high temporal resolution. However, conventional Doppler method merely measures the velocity component along the ultrasonic beam. In the present study, two-dimensional blood flow vectors in carotid artery are measured by dual-angle Doppler measurement and validation of the method is performed in comparison with particle image velocimetry. Further, wall shear stress is calculated by flow distribution in the carotid artery. The study contributes to understand the pathophysiology of atherosclerosis in a noninvasive manner.
Non-invasive in-situ quantitative observation of biological cells by acoustic microscopy Peer-reviewed

Naohiro Hozumi, Kyoichi Takanashi, Mamoru Washiya, Sachiko Yoshida, Kazuto Kobayashi, Yoshifumi Saijo

The Journal of the Acoustical Society of America　140　(4)　3245　2016
A novel biodegradable external mesh stent improved long-term patency of vein grafts by inhibiting intimal-medial hyperplasia in an experimental canine model. Peer-reviewed

Sato A, Kawamoto S, Watanabe M, Suzuki Y, Takahashi G, Masaki N, Kumagai K, Saijo Y, Tabayashi K, Saiki Y

General thoracic and cardiovascular surgery　64　(1)　1-9　2016/01

DOI： 10.1007/s11748-015-0591-2 　

ISSN：1863-6705
Acoustic Impedance Estimation Using Calibration Curve for Scanning Acoustic Impedance Microscope Peer-reviewed

Gunawan Agus Indra, Saijo Yoshifumi, Hozumi Naohiro, Yoshida Sachiko, Kobayashi Kazuto, Yamamoto Seiji

2016 INTERNATIONAL CONFERENCE ON KNOWLEDGE CREATION AND INTELLIGENT COMPUTING (KCIC)　240-245　2016
Perspective Imaging of Flow in Arterial Model Obtained with Continuous Wave Doppler Focusing Technique Peer-reviewed

Ryo Nagaoka, Katsuhiro Sasaki, Seiichi Zama, Masaaki Nagone, Hiroshi Nagai, Yasuhito Takeuchi, Yoshifumi Saijo

2016 38TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY (EMBC)　2315-2318　2016
Publisher: IEEE
DOI： 10.1109/EMBC.2016.7591193 　

ISSN：1557-170X

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Flowing emboli in the circulatory system cause fatal diseases such as stroke or pulmonary embolism. Conventional transcranial Doppler ultrasound for detection of emboli requires precise positioning by experienced examiner. In the present study, an easier emboli detection device by visualizing perspective view of blood vessel is proposed. The perspective image was obtained with continuous wave (CW) Doppler ultrasound from 2-dimensional array probe. CW Doppler signal from each element was focused by novel beam forming algorithm to obtain en face images at arbitrary depth to form perspective image. Flow in arterial phantom was clearly visualized with CW Doppler focusing technique. The measured flow speed was 0.75 m/s (the theoretical flow speed: 0.796 m/s). The device may contribute for non-invasive and easier diagnosis of flowing emboli to prevent fatal embolus diseases at early stage.
3D Gabor Wavelet based Vessel Filtering of Photoacoustic Images Peer-reviewed

Israr Ul Haq, Ryo Nagoaka, Takahiro Makino, Takuya Tabata, Yoshifumi Saijo

2016 38TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY (EMBC)　3883-3886　2016
Publisher: IEEE
DOI： 10.1109/EMBC.2016.7591576 　

ISSN：1557-170X

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Filtering and segmentation of vasculature is an important issue in medical imaging. The visualization of vasculature is crucial for the early diagnosis and therapy in numerous medical applications. This paper investigates the use of Gabor wavelet to enhance the effect of vasculature while eliminating the noise due to size, sensitivity and aperture of the detector in 3D Optical Resolution Photoacoustic Microscopy (OR-PAM). A detailed multi-scale analysis of wavelet filtering and Hessian based method is analyzed for extracting vessels of different sizes since the blood vessels usually vary with in a range of radii. The proposed algorithm first enhances the vasculature in the image and then tubular structures are classified by eigenvalue decomposition of the local Hessian matrix at each voxel in the image. The algorithm is tested on non-invasive experiments, which shows appreciable results to enhance vasculature in photo-acoustic images.
Numerical analysis of acoustic impedance microscope utilizing acoustic lens transducer to examine cultured cells Peer-reviewed

Agus Indra Gunawan, Naohiro Hozumi, Kenta Takahashi, Sachiko Yoshida, Yoshifumi Saijo, Kazuto Kobayashi, Seiji Yamamoto

ULTRASONICS　63　102-110　2015/12
Publisher: ELSEVIER SCIENCE BV
DOI： 10.1016/j.ultras.2015.06.016 　

ISSN：0041-624X

eISSN：1874-9968

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A new technique is proposed for non-contact quantitative cell observation using focused ultrasonic waves. This technique interprets acoustic reflection intensity into the characteristic acoustic impedance of the biological cell. The cells are cultured on a plastic film substrate. A focused acoustic beam is transmitted through the substrate to its interface with the cell. A two-dimensional (2-D) reflection intensity profile is obtained by scanning the focal point along the interface. A reference substance is observed under the same conditions. These two reflections are compared and interpreted into the characteristic acoustic impedance of the cell based on a calibration curve that was created prior to the observation. To create the calibration curve, a numerical analysis of the sound field is performed using Fourier Transforms and is verified using several saline solutions. Because the cells are suspended by two plastic films, no contamination is introduced during the observation. In a practical observation, a sapphire lens transducer with a center frequency of 300 MHz was employed using ZnO thin film. The objects studied were co-cultured rat-derived glial (astrocyte) cells and glioma cells. The result was the clear observation of the internal structure of the cells. The acoustic impedance of the cells was spreading between 1.62 and 1.72 MNs/m(3). Cytoskeleton was indicated by high acoustic impedance. The introduction of cytochalasin-B led to a significant reduction in the acoustic impedance of the glioma cells; its effect on the glial cells was less significant. It is believed that this non-contact observation method will be useful for continuous cell inspections. (C) 2015 Elsevier B.V. All rights reserved.
In memory: Floyd Dunn Peer-reviewed

Yoshifumi Saijo

Journal of Medical Ultrasonics　42　(4)　605　2015/10/01
Publisher: Springer-Verlag Tokyo
DOI： 10.1007/s10396-015-0656-y 　

ISSN：1613-2254 1346-4523
Viscoelastic Imaging Using Acoustic Impedance Microscope and Its Application to Biological Tissue Peer-reviewed

Naohiro Hozumi, Shota Kajima, Agus Indra Gunawan, Sachiko Yoshida, Kazuto Kobayashi, Yoshifumi Saijo, Seiji Yamamoto

2015 IEEE International Ultrasonics Symposium　1G-4　2015/10
Publisher: IEEE
DOI： 10.1109/ULTSYM.2015.0172 　

ISSN：1948-5719
Development of an Ultrasound Microscope Combined With Optical Microscope for Multiparametric Characterization of a Single Cell Peer-reviewed

Mototaka Arakawa, Joe Shikama, Koki Yoshida, Ryo Nagaoka, Kazuto Kobayashi, Yoshifumi Saijo

IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL　62　(9)　1615-1622　2015/09
Publisher: IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
DOI： 10.1109/TUFFC.2014.006865 　

ISSN：0885-3010

eISSN：1525-8955

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Biomechanics of the cell has been gathering much attention because it affects the pathological status in atherosclerosis and cancer. In the present study, an ultrasound microscope system combined with optical microscope for characterization of a single cell with multiple ultrasound parameters was developed. The central frequency of the transducer was 375 MHz and the scan area was 80 x 80 mu m with up to 200 x 200 sampling points. An inverted optical microscope was incorporated in the design of the system, allowing for simultaneous optical observations of cultured cells. Two-dimensional mapping of multiple ultrasound parameters, such as sound speed, attenuation, and acoustic impedance, as well as the thickness, density, and bulk modulus of specimen/cell under investigation, etc., was realized by the system. Sound speed and thickness of a 3T3-L1 fibroblast cell were successfully obtained by the system. The ultrasound microscope system combined with optical microscope further enhances our understanding of cellular biomechanics.
Numerical analysis of ultrasound propagation and reflection intensity for biological acoustic impedance microscope Peer-reviewed

Agus Indra Gunawan, Naohiro Hozumi, Sachiko Yoshida, Yoshifumi Saijo, Kazuto Kobayashi, Seiji Yamamoto

ULTRASONICS　61　79-87　2015/08
Publisher: ELSEVIER SCIENCE BV
DOI： 10.1016/j.ultras.2015.03.010 　

ISSN：0041-624X

eISSN：1874-9968

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This paper proposes a new method for microscopic acoustic imaging that utilizes the cross sectional acoustic impedance of biological soft tissues. In the system, a focused acoustic beam with a wide band frequency of 30-100 MHz is transmitted across a plastic substrate on the rear side of which a soft tissue object is placed. By scanning the focal point along the surface, a 2-D reflection intensity profile is obtained. In the paper, interpretation of the signal intensity into a characteristic acoustic impedance is discussed. Because the acoustic beam is strongly focused, interpretation assuming vertical incidence may lead to significant error. To determine an accurate calibration curve, a numerical sound field analysis was performed. In these calculations, the reflection intensity from a target with an assumed acoustic impedance was compared with that from water, which was used as a reference material. The calibration curve was determined by changing the assumed acoustic impedance of the target material. The calibration curve was verified experimentally using saline solution, of which the acoustic impedance was known, as the target material. Finally, the cerebellar tissue of a rat was observed to create an acoustic impedance micro profile. In the paper, details of the numerical analysis and verification of the observation results will be described. (C) 2015 Elsevier B.V. All rights reserved.
Effects of cavitation-enhanced heating in high-intensity focused ultrasound treatment on shear wave imaging Peer-reviewed

Ryosuke Iwasaki, Ryo Nagaoka, Ryo Takagi, Kota Goto, Shin Yoshizawa, Yoshifumi Saijo, Shin-ichiro Umemura

JAPANESE JOURNAL OF APPLIED PHYSICS　54　(7)　07HF21　2015/07
Publisher: IOP PUBLISHING LTD
DOI： 10.7567/JJAP.54.07HF11 　

ISSN：0021-4922

eISSN：1347-4065

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High-intensity focused ultrasound (HIFU) therapy is a less invasive method of cancer treatment, in which ultrasound is generated outside the body and focused at the tumor tissue to be thermally coagulated. To enhance the safety, accuracy, and efficiency of HIFU therapy, "multiple-triggered HIFU" has been proposed as a method of cavitation-enhanced heating to shorten treatment time. In this study, we also propose shear wave elastography (SWE) to noninvasively monitor the cavitation-enhanced heating. Results show that the increase in shear wave velocity was observed in the coagulation area, but it was significantly slower when cavitation occurred. This suggests that the cavitation-enhanced heating requires a significantly longer cooling time before the accurate measurement of shear modulus than heating without generating bubbles. (C) 2015 The Japan Society of Applied Physics
Measurements of Blood Flow and Blood Pressure under Different Indoor Temperature and Body Postural Conditions, and Development of a New Human Simulation Model Peer-reviewed

H. Sakamoto, Y. Chiba, T. Hayase, K. Funamoto, Y. Saijo, T. Goto

Healthy Buildings Europe 2015　437-1-437-8　2015/05/18
腱板骨付着部変性における酸化ストレスの寄与

森川大智, 糸魚川善昭, 野尻英俊, 佐野博高, 井樋栄二, 西條芳文, 金子和夫, 野沢雅彦, 清水孝彦

日本整形外科学会雑誌　89　(2)　S434-S434　2015/03
Publisher: (公社)日本整形外科学会
ISSN：0021-5325
Simultaneous evaluation of articular cartilage and subchondral bone from immobilized knee in rats by photoacoustic imaging system Peer-reviewed

Yoshihiro Hagiwara, Takuya Izumi, Yutaka Yabe, Mika Sato, Kazuaki Sonofuchi, Kenji Kanazawa, Masashi Koide, Yoshifumi Saijo, Eiji Itoi

JOURNAL OF ORTHOPAEDIC SCIENCE　20　(2)　397-402　2015/03
Publisher: SPRINGER JAPAN KK
DOI： 10.1007/s00776-014-0692-2 　

ISSN：0949-2658

eISSN：1436-2023

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Osteoarthritis is not only a disease of articular cartilage, but also of subchondral bone. It is difficult for ultrasound to evaluate subchondral bone because of permeability. This study aimed to evaluate sequential osteoarthritic changes of articular cartilage and subchondral bone from immobilized knees in rats with a photoacoustic (PA) imaging system. The unilateral knee joints of adult male rats were immobilized with an internal fixator (IM group) for 4 and 8 weeks. Sham operated animals had holes drilled in the femur and tibia and screws inserted without a plate (control group). A whole proximal third of the tibia was obtained. The specimens were immersed in normal saline and scanned by the PA imaging system, which can create both ultrasound (US) and PA imaging. After the scanning, specimens were fixed with paraformaldehyde, decalcified and embedded in paraffin. Thinly sliced tissues were prepared for histological evaluation. PA signals from the articular cartilage and subchondral bone were independently evaluated. Gross observations showed that fibrillation occurred in the superficial layers and permeability of the articular cartilage increased. Histological observations showed that the articular cartilage became thicker and the bone marrow space expanded during immobilization. US images by the PA imaging system could evaluate the articular cartilage. PA signals from the articular cartilage and subchondral bone increased with the duration of immobilization and the difference, compared to the control group, was significant. The PA imaging system could evaluate articular cartilage and subchondral bone simultaneously.
Measurement of skin elasticity using high frequency ultrasound elastography with intrinsic deformation induced by arterial pulsation Peer-reviewed

Ryo Nagaoka, Yoshifumi Saijo

Interface Oral Health Science 2014: Innovative Research on Biosis-Abiosis Intelligent Interface　245-255　2015/01/01
Publisher: Springer Japan
DOI： 10.1007/978-4-431-55192-8_21 　

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Mechanical property of the skin is one of the important factors for diagnosis of human skin diseases. In this paper, we proposed a novel method for estimation of shear wave velocity from deformation induced by an arterial pulsation. The induced deformation was measured by high frequency ultrasound. The elasticity of the in vivo human skin is evaluated based on the calculated parameters. P(VDF-TrFE) transducer with the central frequency of 100 MHz was used for imaging. The aperture diameter of the transducer was 2 mm, and the focal length was 4 mm. The repetition rate was 2,600 Hz. The sampling rate was 1 GS/s with 8 bit. The velocity induced by pulsation was measured by 1-D cross-correlation method at each depth. The shear wave velocity was estimated from the measured velocity. The shear wave velocity at the epidermis was 0.14 m/s, and the velocity at the dermis was 0.06 m/s. Because the stiffness of the skin was proportional to the shear wave velocity, the elasticity of the epidermis was higher than that of the dermis. These estimated elasticity well conformed to the histology of the skin and the past reports.
Adaptive Spatial Filtering with Principal Component Analysis for Biomedical Photoacoustic Imaging Peer-reviewed

Ryo Nagaoka, Rena Yamazaki, Yoshifumi Saijo

Proceedings of the 2015 ICU International Congress on Ultrasonics　70　1161-1164　2015
Publisher: ELSEVIER SCIENCE BV
DOI： 10.1016/j.phpro.2015.08.249 　

ISSN：1875-3892

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Photoacoustic (PA) signal is very sensitive to noise generated by peripheral equipment such as power supply, stepping motor or semiconductor laser. Band-pass filter is not effective because the frequency bandwidth of the PA signal also covers the noise frequency. The objective of the present study is to reduce the noise by using an adaptive spatial filter with principal component analysis (PCA). (C) 2015 The Authors. Published by Elsevier B.V.
Monitoring of lesions induced by cavitation-enhanced high-intensity focused ultrasound using shear wave elastography Peer-reviewed

Iwasaki, R, Nagaoka, R, Saijo, Y, Umemura, S.-I, Takagi, R, Jimbo, H, Yoshizawa, S

IEEE Int. Ultrason. Symp., IUS　7329182　2015

DOI： 10.1109/ULTSYM.2015.0042 　

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Shear wave elastography is expected as a noninvasive monitoring method in high-intensity focused ultrasound treatment. Since elastography is usually applied to detect a lesion near a superficial layer, it is challenging to induce and propagate shear waves in deep tissue. Acoustic cavitation bubbles have the potential to promote the efficiency of the treatment; however the presence of remaining microbubbles may interfere with the shear wave propagation and make the detection of the accompanying displacements difficult. In this paper, it is examined whether the detection of the region where increased shear wave propagation velocity in ex vivo tissue is possible even in the presence of microbubbles and 'HIFU push' shear wave elastography has the advantage in terms of shear wave induction in deep tissue compared with a conventional technique by irradiating push beams from the same therapeutic transducer as HIFU exposure.
Measurement of acoustic properties of cells using high frequency acoustic microscopy

T. Igo, M. Arakawa, K. Kobayashi, R. Nagaoka, Y. Saijo

Proc. 13th International Symp. Advanced Biomedical Ultrasound　20-20　2015
Basic study of intrinsic elastography: Relationship between tissue stiffness and propagation velocity of deformation induced by pulsatile flow Peer-reviewed

Nagaoka, R, Iwasaki, R, Arakawa, M, Kobayashi, K, Yoshizawa, S, Umemura, S.-I, Saijo, Y

Japanese Journal of Applied Physics　54　(7)　07HF08　2015
Publisher: Institute of Physics
DOI： 10.7567/JJAP.54.07HF08 　

ISSN：0021-4922

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We proposed an estimation method for a tissue stiffness from deformations induced by arterial pulsation, and named this proposed method intrinsic elastography (IE). In IE, assuming that the velocity of the deformation propagation in tissues is closely related to the stiffness, the propagation velocity (PV) was estimated by spatial compound ultrasound imaging with a high temporal resolution of 1 ms. However, the relationship between tissue stiffness and PV has not been revealed yet. In this study, the PV of the deformation induced by the pulsatile pump was measured by IE in three different poly(vinyl alcohol) (PVA) phantoms of different stiffnesses. The measured PV was compared with the shear wave velocity (SWV) measured by shear wave imaging (SWI). The measured PV has trends similar to the measured SWV. These results obtained by IE in a healthy male show the possibility that the mechanical properties of living tissues could be evaluated by IE.
Preventing effects of joint contracture by high molecular weight hyaluronan injections in a rat immobilized knee model. Peer-reviewed

Kanazawa K, Hagiwara Y, Tsuchiya M, Yabe Y, Sonofuchi K, Koide M, Sekiguchi T, Itaya N, Ando A, Saijo Y, Itoi E

International journal of clinical and experimental pathology　8　(4)　3426-3440　2015
Macrophage with Gold Nanorod Visualized by Optical-Resolution and Acoustic-Resolution Photoacoustic Microscopes Peer-reviewed

Rena Yamazaki, Koetsu Ogasawara, Mitsuhiro Fujiwara, Kazuto Kobayashi, Yoshifumi Saijo

2015 37TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY (EMBC)　2387-2390　2015
Publisher: IEEE
DOI： 10.1109/EMBC.2015.7318874 　

ISSN：1557-170X

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Macrophages play a key role in inflammation and they are frequently observed in vulnerable atherosclerotic plaque. In the present study, macrophages phagocytosing gold nanorod (AuNR) were observed by optical-resolution (OR) and acoustic-resolution (AR) photoacoustic microscope (PAM). The OR-PAM consisted of diode laser optically focused to 60 micron and planar ultrasonic transducer with the central frequency of 8 MHz placed under the object. AR-PAM consisted of concave ultrasonic transducer with the central frequency of 20 MHz and optical fiber through the center hole of the transducer for laser irradiation. First, PA signal from gold, silver and copper wire were measured in order to determine the best metal substrate for enhancing PA contrast. Gold generated largest PA signal. AuNR with the resonance wavelength of 1064 nm was co-cultured with the macrophages for phagocytosis. PA signal was successfully detected from macrophages with AuNR by both OR-PAM and AR-PAM. PA imaging of the macrophages with AuNR indicates inflammation in the vulnerable plaque and AR-PAM method would be applicable for clinical settings.
Intrinsic Elastography and Its Dependence on Arterial Flow Volume Peer-reviewed

Ryo Nagaoka, Kazuto Kobayashi, Shin Yoshizawa, Shin-ichiro Umemura, Yoshifumi Saijo

2015 37TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY (EMBC)　6309-6312　2015
Publisher: IEEE
DOI： 10.1109/EMBC.2015.7319835 　

ISSN：1557-170X

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We propose a new estimation method of tissues stiffness from deformation induced by arterial pulsation. The new method was named Intrinsic Elastography (IE). Under two assumptions that the deformation induced by pulsation propagates throughout the body, and the propagation velocity (PV) is closely related to the mechanical properties of tissues, the IE can evaluate the tissue stiffness based on the PV. However, this method has an issue that the observed PVs change with the changes of amounts of the flow. In this paper, we propose the new estimation method in order to estimate true shear elasticity in spite of the changes. The results was compared to the results of SWI. The results was almost identical to the result of SWI, or showed the similar results.
Measurement of regional pulse-wave velocity using spatial compound imaging of the common carotid artery in vivo Peer-reviewed

Ryo Nagaoka, Genta Masuno, Kazuto Kobayashi, Shin Yoshizawa, Shin-ichiro Umemura, Yoshifumi Saijo

ULTRASONICS　55　92-103　2015/01
Publisher: ELSEVIER SCIENCE BV
DOI： 10.1016/j.ultras.2014.07.018 　

ISSN：0041-624X

eISSN：1874-9968

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Pulse-wave velocity (PWV) is an important index for diagnosing cardiovascular diseases. The pulse wave is volumetric change induced by heartbeat or inflowing blood, and significantly depends on the propagating path and stiffness of the artery. In this study, PWV of the propagating wave was visualized using spatial compound imaging with high temporal resolution. The frame rate was 1000 Hz, or a time interval of 1 ms. Subjects were four young healthy males and one young healthy female (n = 5, age: 23.8 +/- 1.17 years old), and the measurement area was the right common carotid artery. PWVs in four phases (the four phases of heart valve opening and closing) were investigated during a cardiac cycle. In phase I, the heart pulsates. In phase II, the tricuspid and mitral valves close, and the aortic and pulmonic valves open. In phase III, the tricuspid and mitral valves open, and the aortic and pulmonic valves close. In phase IV, the propagating wave is reflected. PWVs in phases II and III were easily observed. PWVs were 3.52 +/- 1.11 m/s in phase I, 5.62 +/- 0.30 m/s in phase II, 7.94 +/- 0.85 m/s in phase III, and -4.60 +/- 0.99 m/s for the reflective wave. PWV was measured using Spatial Compound Imaging with high temporal resolution, and the PWV in each phase may be used as the index for diagnosing stages of arteriosclerosis progression. (C) 2014 Elsevier B.V. All rights reserved.
Joint haemorrhage partly accelerated immobilization-induced synovial adhesions and capsular shortening in rats. International-journal Peer-reviewed

Yoshito Onoda, Yoshihiro Hagiwara, Akira Ando, Takashi Watanabe, Eiichi Chimoto, Hideaki Suda, Yutaka Yabe, Yoshifumi Saijo, Eiji Itoi

Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA　22　(11)　2874-83　2014/11

DOI： 10.1007/s00167-013-2659-9 　

ISSN：0942-2056

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PURPOSE: To elucidate the effects of intra-articular haemorrhage on the joint capsule of immobilized knees in rats. METHODS: The unilateral knee joints were immobilized using a plastic plate and screws. Sham operated rats had only screws inserted. A single injection of fresh autologous blood was given postoperatively into the knee joints of the immobilized blood injection (Im-B) and the Sham blood injection (Sm-B) groups. Normal saline was administered for the immobilized-saline injection (Im-S) group. Sagittal sections were prepared from the medial midcondylar region of the knee and assessed with histological, histomorphometric, and immunohistochemical methods. The range of motion (ROM) was measured, and the mechanical property of the capsule was assessed by scanning acoustic microscope. RESULTS: Absorption of the injected blood was delayed and made severe adhesions in the Im-B group. The length of the synovial membrane in the Im-B group was significantly shorter than that of the other groups. The ROM was significantly restricted in the Im-B group compared with the other groups. The elasticity of the posterior capsule in the Im-B group was significantly lower than that in the Sm-B group. Iron deposition was observed in the Im-B and Sm-B groups. Strong immunoreactivities of CD68, TGF-β1, and α-SMA were observed in the adhesion area of the Im-B group. Joint immobilization with blood injection caused severe capsular adhesion and limited range of motion. Immunostaining related to fibrosis increased with joint haemorrhage. CONCLUSION: Intra-articular haemorrhage with joint immobilization might be an accelerated risk factor for joint contracture. It is likely that leaving a haematoma inside an immobilized joint should be avoided.
Acoustic impedance microscopy for biological tissue characterization Peer-reviewed

Kazuto Kobayashi, Sachiko Yoshida, Yoshifumi Saijo, Naohiro Hozumi

ULTRASONICS　54　(7)　1922-1928　2014/09
Publisher: ELSEVIER SCIENCE BV
DOI： 10.1016/j.ultras.2014.04.007 　

ISSN：0041-624X

eISSN：1874-9968

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A new method for two-dimensional acoustic impedance imaging for biological tissue characterization with micro-scale resolution was proposed. A biological tissue was placed on a plastic substrate with a thickness of 0.5 mm. A focused acoustic pulse with a wide frequency band was irradiated from the "rear side" of the substrate. In order to generate the acoustic wave, an electric pulse with two nanoseconds in width was applied to a PVDF-TrFE type transducer. The component of echo intensity at an appropriate frequency was extracted from the signal received at the same transducer, by performing a time frequency domain analysis. The spectrum intensity was interpreted into local acoustic impedance of the target tissue. The acoustic impedance of the substrate was carefully assessed prior to the measurement, since it strongly affects the echo intensity. In addition, a calibration was performed using a reference material of which acoustic impedance was known. The reference material was attached on the same substrate at different position in the field of view. An acoustic impedance microscopy with 200 x 200 pixels, its typical field of view being 2 x 2 mm, was obtained by scanning the transducer. The development of parallel fiber in cerebella cultures was clearly observed as the contrast in acoustic impedance, without staining the specimen. The technique is believed to be a powerful tool for biological tissue characterization, as no staining nor slicing is required. (C) 2014 Elsevier B.V. All rights reserved.
Studies on the basic technology of “Sono-cytometry” Peer-reviewed

Yosuke Komatsu, Ryo Nagaoka, Kenichi Funamoto, Toshiyuki Hayase, Nobuo Masauzi, Hiroshi Kanai, Yoshifumi Saijo

Transactions of Japanese Society for Medical and Biological Engineering　52　351-O-352　2014/08/17
Publisher: Japan Soc. of Med. Electronics and Biol. Engineering
DOI： 10.11239/jsmbe.52.O-351 　

ISSN：1347-443X 1881-4379

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Flow cytometry is widely used to classify individual cells optically but blood sampling is required for cell measurement in blood. If the principle of the cytometry is applicable directly in vivo, diagnosis of malaria would become easier. However, optical observation of the cell in blood flow is difficult because absorption and scattering of the light is large in vivo. In this study, novel ultrasonic method called "Sono-cytometry" for differentiating cells is proposed. The backscatter signal from the sphere with the diameter of 8 and 10-micron were detected by a transducer with the central frequency of 75 MHz. When the theoretical value is calculated from Faran-Hickling Model, linear approximate slope matched with theoretical slope. When calculating the slope of theoretical value by changing the spherical diameter, the slope value was very different between 8 and 10 micron. The result shows that it is possible that this method can classify spheres.
Automated detection of optic disc using vessels tracking Peer-reviewed

Israr Ul Haq, Usman Akram, Yoshifumi Saijo

Transactions of Japanese Society for Medical and Biological Engineering　52　283-O-284　2014/08/17
Publisher: Japan Soc. of Med. Electronics and Biol. Engineering
DOI： 10.11239/jsmbe.52.O-283 　

ISSN：1347-443X 1881-4379

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Optic disc is an important anatomical feature of the retinal image and helps in the diagnosis of eye diseases. The proposed method is based on the characteristics of retinal image. An important characteristic of the retinal image is that blood vessels egress from the optic disc and become thin as they move away from the optic disc. If blood vessels are tracked and features are calculated then they end up on the optic disc. Given a retinal image the proposed method first enhances the blood vessels using 2-D Gabor wavelets and segmenting the blood vessels using iterative thresholding technique to join the vessels properly. The resultant image is thinned using morphological operation and matched with the 2-D Gaussian function by tracking the blood vessels. Finally Optic disc is localized in a window. The proposed method is evaluated using publicly available databases and results show that the proposed method identifies optic disc with high accuracy.
Measurement of sound speed of skin by using ultrasonic microscopy Peer-reviewed

Miki Horie, Ryo Nagaoka, Kazuto Kobayashi, Kenshi Yamazaki, Yoshifumi Saijo

Transactions of Japanese Society for Medical and Biological Engineering　52　323-O-324　2014/08/17
Publisher: Japan Soc. of Med. Electronics and Biol. Engineering
DOI： 10.11239/jsmbe.52.O-323 　

ISSN：1347-443X 1881-4379

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Ultrasonic microscopy characterizes mechanical properties of pathological sections without staining by measuring ultrasonic parameters such as sound speed or attenuation. The sound speed of melanoma which is a malignant skin tumor was measured by using a high frequency ultrasonic microscopy in this study. The optical image of HE-stained sections of melanoma specimen and the image from the ultrasonic microscopy were corresponded. The transducer of the ultrasonic microscopy was set as central frequency of 80MHz, focal length of 1.5mm and diameter 1.2mm. A fast scanning was done and the image size was 300 * 300 and 2.4mm * 2.4mm. Randomly ROI was taken and the sound speed was measured. At this stage, the sound speed of melanoma is 1545m/s. It provides the information for the objective judgment of skin diseases.
Development of innovative photoacoustic microscopy with application of transparent piezo-electronic element Peer-reviewed

Yoshifumi Saijo, Yuji Matsuura, Katsuyoshi Washio

Transactions of Japanese Society for Medical and Biological Engineering　52　56-SY-57　2014/08/17
Publisher: Japan Soc. of Med. Electronics and Biol. Engineering
DOI： 10.11239/jsmbe.52.SY-56 　

ISSN：1347-443X 1881-4379

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Innovative photoacoustic imaging system with transparent piezo-electronic material was developed. High quality ZnO thin film was processed in a certain condition. VZO layer was acted as the electrode. Optical fiber for transmission of the high power laser was assessed. The imaging system successfully visualized normal and osteoarthritis knee joints of rats. The study was conducted with the collaboration of academia and industry.
Measurement of acoustic parameters of single cell by ultrasound microscope Peer-reviewed

Koki Yoshida, Rami Abuhabsah, Alexander D. Pawlicki, Joe Shikama, Ryo Nagaoka, Kazuto Kobayashi, Yoshifumi Saijo, William D. O'Brien

Transactions of Japanese Society for Medical and Biological Engineering　52　341-O-342　2014/08/17
Publisher: Japan Soc. of Med. Electronics and Biol. Engineering
DOI： 10.11239/jsmbe.52.O-341 　

ISSN：1347-443X 1881-4379

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Recently, the biomechanics of cell has received attention because the study on the biomechanics will lead to development of diagnosis and treatment of cancer and arteriosclerosis. Most methods on the measurement of biomechanics require direct contact to the cell. Because the square of sound speed is proportional to the cell elasticity, non-contact measurement of sound speed with ultrasound microscopy can obtain the mechanical properties. In the present study, quantitative measurement of cell parameters such as thickness, sound speed, acoustic impedance, density, bulk modulus, attenuation and images of each parameter are successfully obtained. The transducer had 150 MHz center frequency and f-number of 0.88 and focal length of 3.8 mm. Pulse spectrum analysis was applied to calculate thickness and sound speed of the cells because the signal from a cell surface was not distinguished from the echo from the petri dish. This study may contribute measurement of cellular biomechanics.
Beam profile measurement and optimization in the high-frequency annular array transducer Peer-reviewed

Akira Tada, Ryo Nagaoka, Kazuto Kobayashi, Yoshifumi Saijo

Transactions of Japanese Society for Medical and Biological Engineering　52　355-O-356　2014/08/17
Publisher: Japan Soc. of Med. Electronics and Biol. Engineering
DOI： 10.11239/jsmbe.52.O-355 　

ISSN：1347-443X 1881-4379

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Annular array transducers are multi-elements and arrayed in annular. By providing a delay line for each element, we can vary the focal length, so beam width is narrower, and the SNR is better than the conventional single element transducers. The annular array utilized in these studies consisted of four elements, had a geometric focus of 18 mm, and a center frequency of 30 MHz. We measured the voltage of received signal and the delay time of the case with a wire phantom in the case of 16 types, and practiced the synthetic focusing. The voltage of received signal was maximal at 18 mm as expected. For the delay time, the measured values with the theoretical values were consistent with the overall trend, but the error occurred between the both values. When we practiced the synthetic focusing by shifting the amount of the delay time, depth of field became approximately twice.
Development of acoustic microscope for biological tissue and its application Peer-reviewed

Mototaka Arakawa, Joe Shikama, Koki Yoshida, Ryo Nagaoka, Kazuto Kobayashi, Yoshifumi Saijo

Transactions of Japanese Society for Medical and Biological Engineering　52　5-SY-6　2014/08/17
Publisher: Japan Soc. of Med. Electronics and Biol. Engineering
DOI： 10.11239/jsmbe.52.SY-5 　

ISSN：1347-443X 1881-4379

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Scanning acoustic microscope (SAM) is useful for tissue characterization because it is possible to obtain two-dimensional information of acoustic properties, viz., velocity and attenuation coefficient, in the microscopic region. We have studied development of SAM and its application to quantitative evaluation of biological tissue and a single cell. We developed a SAM system using a pulse signal and analytical procedure to obtain acoustic properties. Recently, we also developed an acoustic and optic hybrid system to obtain both optical and elastic images and acoustic properties for a single cell in real time. We applied the system to a 3T3-L1 mouse fibroblast cell using an acoustic lens with center frequency of 250 MHz. Measurements were conducted immediately and enough later after takeoff from the culture apparatus. Sound velocities were 1602 m/s and 1558 m/s, and thicknesses were 7.9 μm and 16 μm, respectively. Properties changes of the cell were successfully detected quantitatively.
Visualization of pulse propagation with high frame rate spatial compound imaging Peer-reviewed

Ryo Nagaoka, Genta Masuno, Kazuto Kobayashi, Shin Yoshizawa, Shin-ichiro Umemura, Yoshifumi Saijo

Transactions of Japanese Society for Medical and Biological Engineering　52　353-O-354　2014/08/17
Publisher: Japan Soc. of Med. Electronics and Biol. Engineering
DOI： 10.11239/jsmbe.52.O-353 　

ISSN：1347-443X 1881-4379

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Shear wave Imaging is a technique that estimates tissue stiffness by measuring shear wave induced by Push Beam. However, a decay of estimate accuracy may accrue due to motions of such as pulsation and breathing. In this presentation, we propose estimation method of tissue stiffness based on the pulse propagation.Verasonic and 7.5 MHz Linear Probe were utilized to acquire raw data. The frame rate was 1 kfps. The identical data was used to measure the velocity by a modified 1D-cross-correlation-algorithm. A measurement area was right common carotid artery of 24-year-old healthy male.The pulse propagation was visualized with high-frame-rate ultrasound imaging. The dispersion-relation was observed. For example, the velocity of artery was 6.08 ± 0.19 m/s, and that of muscle was 7.43 ± 0.30 m/s at 15 Hz. It was possible to visualize the appearance of propagation induced by pulsation. The dispersion relation was revealed by the proposal method.
Observation of artherosclerosis by photoacoustic microscopy Peer-reviewed

Mika Sato, Rena Yamazaki, Yoshihiro Hagiwara, Yuji Matsuura, Kazuto Kobayashi, Yoshifumi Saijo

Transactions of Japanese Society for Medical and Biological Engineering　52　449-O-450　2014/08/17
Publisher: Japan Soc. of Med. Electronics and Biol. Engineering
DOI： 10.11239/jsmbe.52.O-449 　

ISSN：1347-443X 1881-4379

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Photoacoustic (PA) imaging is a non-invasive diagnostic approach using PA effect. This study is performed to develop OR-PAM system and to image the sample of arteriosclerosis of the rat by using developed OR-PAM system and investigated the usability of PA imaging in histopathologic examination. As a result, red blood cells which caused the thrombus existed in the atheroma in the sample. In the present study, we developed OR-PAM system and visualized the atheroma with thrombus in the sample of arteriosclerosis of the rat by using developed OR-PAM system. Thus, PA imaging using OR-PAM has usability for histopathologic examination of arteriosclerosis.
Development of optical and acoustic hybrid microscope for visualization of a single cell Peer-reviewed

Joe Shikama, Yu Sato, Kazuto Kobayashi, Koki Yoshida, Ryo Nagaoka, Yoshifumi Saijo

Transactions of Japanese Society for Medical and Biological Engineering　52　345-O-346　2014/08/17
Publisher: Japan Soc. of Med. Electronics and Biol. Engineering
DOI： 10.11239/jsmbe.52.O-345 　

ISSN：1347-443X 1881-4379

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Acoustic microscope can measure the acoustic parameters of living cells. It is expected that disease mechanism is elucidated, and that treatment methods is developed by analyzing structure and function of cells. In this study, the optical and acoustic hybrid microscope has been developed. The ultrasonic transducer has 250 MHz. As a result of imaging the 3T3-L1 mouse fibroblasts, good contrast was achieved in the portion of the cell nucleus and pseudopod in the acoustic image. In addition, two-dimensional color images of thickness and sound speed of the cell were successfully obtained by using time-resolved analysis. The average thickness was 7.9 μm, and sound speed was 1602 m/s.
抗酸化酵素Sod1欠損マウスにおける棘上筋付着部変性の組織学的解析

森川大智, 糸魚川善昭, 野尻英俊, 佐野博高, 井樋栄二, 西條芳文, 金子和夫, 野沢雅彦, 清水孝彦

JOSKAS　39　(4)　266-266　2014/07
Publisher: (一社)日本関節鏡・膝・スポーツ整形外科学会
ISSN：1884-8842
Coronary artery atherectomy reduces plaque shear strains: An endovascular elastography imaging study Peer-reviewed

Zahra Keshavarz-Motamed, Yoshifumi Saijo, Younes Majdouline, Laurent Riou, Jacques Ohayon, Guy Cloutier

ATHEROSCLEROSIS　235　(1)　140-149　2014/07
Publisher: ELSEVIER IRELAND LTD
DOI： 10.1016/j.atherosclerosis.2014.04.022 　

ISSN：0021-9150

eISSN：1879-1484

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Mechanical response and properties of the arterial wall can be used to identify the biomechanical instability of plaques and predict their vulnerability to rupture. Shear strain elastography (SSE) is proposed to identify vulnerable plaque features attributed to mechanical structural heterogeneities. The aims of this study were: 1) to report on the potential of SSE to identify atherosclerotic plaques; and 2) to use SSE maps to highlight biomechanical changes in lesion characteristics after directional coronary atherectomy (DCA) interventions. For this purpose, SSE was imaged using in vivo intravascular ultrasound (IVUS) radio-frequency data collected from 12 atherosclerotic patients before and after DCA intervention. Coronary atherosclerotic plaques (pre-DCA) showed high SSE magnitudes with large affected areas. There were good correlations between SSE levels and soft plaque content (i.e., cellular fibrosis, thrombosis and fibrin) (mean vertical bar SSE vertical bar vs. soft plaque content: r = 0.82, p < 0.01). Significant differences were noticed between SSE images before and after DCA. Stable arteries (post-DCA) exhibited lower values than pre-DCA vessels (e.g., pre-DCA: mean vertical bar SSE vertical bar = 3.9 +/- 0.2% vs. 1.1 +/- 0.2% post-DCA, p < 0.001). Furthermore, SSE magnitude was statistically higher in plaques with a high level of inflammation (e.g., mean vertical bar SSE vertical bar had values of 4.8 + 0.4% in plaques with high inflammation, whereas it was reduced to 1.8 +/- 0.2% with no inflammation, p < 0.01). This study demonstrates the potential of the IVUS-based SSE technique to detect vulnerable plaques in vivo. (C) 2014 Elsevier Ireland Ltd. All rights reserved.
Contribution of oxidative stress to the degeneration of rotator cuff entheses Peer-reviewed

Daichi Morikawa, Yoshiaki Itoigawa, Hidetoshi Nojiri, Hirotaka Sano, Eiji Itoi, Yoshifumi Saijo, Kazuo Kaneko, Takahiko Shimizu

JOURNAL OF SHOULDER AND ELBOW SURGERY　23　(5)　628-635　2014/05
Publisher: MOSBY-ELSEVIER
DOI： 10.1016/j.jse.2014.01.041 　

ISSN：1058-2746

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Background: Rotator cuff degeneration is one of the multiple factors that lead to rotator cuff tears; however, the precise mechanism of such degeneration still remains unclear. In this study, we investigated the supraspinatus tendon enthesis to clarify the link between rotator cuff degeneration and oxidative stress in antioxidant enzyme superoxide dismutase 1 (Sod1)-deficient mice (Sod1(-/-)). Methods: The supraspinatus tendon and humeral head were isolated and fixed to prepare histologic sections from wild-type and Sod1(-/-) male mice at 20 weeks of age. Hematoxylin-eosin staining was performed to assess the histomorphologic structure. To investigate the collagen fibers, we examined spatially aligned collagen fibers using a polarizing microscope and assessed the amount of collagen using immunohistochemical staining. To analyze the tissue elasticity, we measured the tissue acoustic properties using scanning acoustic microscopy. Results: The Sod1(-/-) mice showed histologic changes, such as a misaligned 4-layered structure and fragmented tidemark, in the enthesis. Sod1 loss also decreased the amount of brightly diffracted light and type I collagen, indicating collagen downregulation. The scanning acoustic microscopy analysis showed that the speed and attenuation of sound were increased in the nonmineralized fibrocartilage of the Sod1(-/-) mice, suggesting decreased mechanical properties in the supraspinatus enthesis. Conclusion: Sod1 deficiency-induced degeneration is associated with impaired elasticity in the supraspinatus tendon enthesis, recapitulating human rotator cuff degeneration. These results suggest that intracellular oxidative stress contributes to the degeneration of rotator cuff entheses. (C) 2014 Journal of Shoulder and Elbow Surgery Board of Trustees.
超音波顕微鏡観察における金属イオン試薬添加を利用した観察法の検討(その2)

小林和人, 山田ひかり, 別段碧, 高橋健太, 吉田祥子, 穂積直裕, 西條芳文

超音波医学　41　S466　2014/04/15

ISSN：1346-1176
腱板付着部変性と酸化ストレスの関連性について抗酸化剤を用いた検討

森川大智, 糸魚川善昭, 野尻英俊, 佐野博高, 井樋栄二, 西條芳文, 金子和夫, 野沢雅彦, 清水孝彦

日本整形外科学会雑誌　88　(2)　S91-S91　2014/03
Publisher: (公社)日本整形外科学会
ISSN：0021-5325
High Frame-Rate Estimation of Two-Dimensional Blood Flow Vector Calculated with Bidirectional Doppler Velocity

Masuno Genta, Nagaoka Ryo, Akagawa Osamu, Sasaki Shoya, Yushizawa Shin, Umemura Shin-ichiro, Saijo Yoshifumi

BME　52　O-331-O-332　2014
Publisher: Japanese Society for Medical and Biological Engineering
DOI： 10.11239/jsmbe.52.O-331 　

ISSN：1347-443X

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The blood-flow can be estimated with Doppler ultrasound. However conventional ultrasound system can estimate only one-dimensional component. In this study, an aim is to estimate two-dimensional blood-flow vector by compounding two different one-dimensional components. The objective of the present study is to develop a method to obtain two-dimensional blood-flow vector by application of ultrasound Doppler technique. The two-dimensional blood-flow vector is estimated by compounding two different one-dimensional components of blood-flow vector. Each component was obtained by bidirectional Doppler ultrasound with parallel beamforming using the same probe in order to increase a frame rate. The experiment was conducted for in vivo carotid artery and a bifurcation phantom. In these experiences, two-dimensional blood-flow was observed by this technique. This work was implemented with a frame-rate of 100 Hz. We believe the method of estimating the true blood flow leads to early diagnosis of the diseases like thrombus and plaque.
Measurement of Propagation Wave Velocity of Thyroid Induced by Pulsation Peer-reviewed

Ryo Nagaoka, Shin Yoshizawa, Shin-ichiro Umemura, Yoshifumi Saijo, Kazuto Kobayashi

2014 IEEE INTERNATIONAL ULTRASONICS SYMPOSIUM (IUS)　1136-1139　2014
Publisher: IEEE
DOI： 10.1109/ULTSYM.2014.0279 　

ISSN：1948-5719

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Shear wave imaging is a technique with ultrasound that estimates tissue stiffness by measuring shear wave induced by Push Beam, which is generated by acoustic radiation force. However, the technique requires Push Beam for a duration of several hundred micron seconds to deform tissue, and a decay of estimate accuracy may be attributed to out-of-focus Push Beam generated by motions of pulsation and heartbeat. In this presentation, the propagation velocity of thyroid was measured by ultrasound spatial compound imaging with a high temporal resolution. In this proposal method, two components of particle velocity can be obtained by using spatial compound imaging, and two kinds of propagation velocity can be also estimated from the propagation appearance of each component. Verasonic ultrasound scanner (30 MHz, 16 bit, Redmond, WA) and 7.5 MHz UST-5412 Linear Probe (Hitachi Aloka Medical. Ltd.) were used to acquire RF data. Each plane wave was transmitted at 5 different angles, -18, 18, -9, 9, 0, with each time interval of 200 s to acquire echo data for making one spatial compound image. The data of each angle was processed by parallel beamforming, and a spatial compound image was obtained by superposing five B-mode images. Time interval between each spatial compound image is 1 ms. Therefore, the frame rate of the imaging was 1 kfps. A measurement area was thyroid of a 22-year-old healthy male at short axis view. An appearance of the propagation from the artery to thyroid area induced by pulsation was visualized with high-frame-rate ultrasound imaging. There were obvious difference between the shear waves along lateral direction. It's considered that mechanical properties of tissue can be observed from the propagation. According to our past research, the shear wave along muscle fibers was 7.43 +/- 0.30 m/s at the frequency of 15 Hz. The muscle fiber direction can be distinguished by the proposal method. These results showed possibility of estimation of tissue stiffness by measuring the shear wave induced by pulsation.
Multiparametric Characterization of a Single Cell by an Ultrasound and Optical Combined Microscope

Yoshifumi Saijo, Joe Shikama, Koki Yoshida, Ryo Nagaoka, Mototaka Arakawa, Kazuto Kobayashi

2014 IEEE INTERNATIONAL ULTRASONICS SYMPOSIUM (IUS)　727-730　2014
Publisher: IEEE
DOI： 10.1109/ULTSYM.2014.0179 　

ISSN：1948-5719

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Biomechanics of the cell has been gathering much attention because it affects the pathological status in atherosclerosis and cancer. In the present study, an ultrasound and optical combined microscope system for characterization of a single cell with multiple ultrasound parameters was developed. The central frequency of the transducer was 375 MHz and the scan area was 80 x 80 micron with up to 200 x 200 sampling points. An inversed optical microscope was installed in the system and simultaneous observation of the cells cultured in the petridish was available. Two-dimensional mapping of the multiple ultrasound parameters such as attenuation, sound speed and acoustic impedance as well as the thickness and density of the cell was realized by the system. Sound speed and thickness of 3T3-L1 fibroblast cell were successfully obtained by the system. The ultrasound and optical combined microscope system may contribute to understand the cellular biomechanics.
Two-dimensional Blood Flow Vectors Obtained with Bidirectional Doppler Ultrasound Peer-reviewed

Genta Masuno, Ryo Nagaoka, Aiko Omori, Yasuo Ishikawa, Osamu Akagawa, Mototaka Arakawa, Yoshifumi Saijo

2014 36TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY (EMBC)　5093-5096　2014
Publisher: IEEE
DOI： 10.1109/EMBC.2014.6944770 　

ISSN：1557-170X

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Precise measurement of blood flow is important because blood flow closely correlates formation of thrombus and atherosclerotic plaque. Among clinically applied modalities for blood flow measurement, color Doppler ultrasound shows two-dimensional (2D) distribution of one-dimensional blood flow component along the ultrasound beam. In the present study, 2D blood flow vector is obtained with high temporal and bidirectional Doppler ultrasound technique. Linear array probe with the central frequency of 7.5 MHz and an ultrasound data acquisition system with 128 transmit and 128 receive channels were equipped. Frame rate of 5 kHz was achieved by parallel receive beam forming with a wide transmitted wave. The flow velocity was measured from two different angles by beam steering. The interval of two measurements was 0.8 msec and it was considered as almost one moment to obtain 2D blood flow vector. B-mode image and 2D blood flow vector of the pulsatile flow in a carotid artery model showed small vortex at the bifurcation area. The method was also applied for visualization of in vivo blood flow vector in human carotid arteries. 2D blood flow measurement may predict the risk area of thrombus and plaque formation induced by abnormal blood flow.
"Sonocytometry" - Novel Diagnostic Method of Ultrasonic Differentiation of Cells in Blood Flow Peer-reviewed

Yosuke Komatsu, Ryo Nagaoka, Ken-ichi Funamoto, Toshiyuki Hayase, Nobuo Masauzi, Hiroshi Kanai, Yoshifumi Saijo

2014 36TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY (EMBC)　2761-2764　2014
Publisher: IEEE
DOI： 10.1109/EMBC.2014.6944195 　

ISSN：1557-170X

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Novel diagnostic method named "sonocytometry", in which streaming blood cell is diagnosed by the reflection of high frequency ultrasound from the cell, is proposed. In the present study, the differentiation of the particle size is performed as a basic study on sonocytometry. Ultrasonic backscatter signal from either 80 or 100 mu m diameter polystyrene particles was measured by an ultrasonic transducer with the central frequency of 30 MHz. The spectrum of the reflected signal showed different characteristics according to the particle diameter. Theoretical value of backscatter was calculated by Faran-Hickling model and the correlation coefficient of measured and theoretical value by varying the spherical diameter showed the local maximum value at either 80 or 100 mu m diameter. The principle was also validated on the streaming particles in a flow channel. The method successfully classified the particle size. Sonocytometry would be clinically applied for diagnosis of malaria or leukemia.
腱板付着部変性における酸化ストレスの寄与抗酸化剤による検討

森川大智, 糸魚川善昭, 野尻英俊, 佐野博高, 井樋栄二, 西條芳文, 金子和夫, 清水孝彦

肩関節　38　(1)　182-182　2013/09
Publisher: (一社)日本肩関節学会
ISSN：0910-4461

eISSN：1881-6363
腱板骨付着部変性における酸化ストレスの寄与

森川大智, 清水孝彦, 糸魚川善昭, 川崎隆之, 金子和夫, 佐野博高, 井樋栄二, 西條芳文

肩関節　37　(2)　825-828　2013/09
Publisher: (一社)日本肩関節学会
ISSN：0910-4461

eISSN：1881-6363

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著者等は、体内の主要な抗酸化酵素であるSOD1が酸化・還元バランス制御に重要な役割を担い、Sod1欠損マウスの骨に加齢性変化がみられることを報告してきた。今回、Sod1欠損マウスの棘上筋腱骨付着部を解析することにより、酸化ストレスが腱板骨付着部に与える影響について検討した。その結果、同マウスの棘上筋腱骨付着部にはヒト腱板の変性像と類似した組織所見が認められ、腱板骨付着部の変性に酸化ストレスが関与していることが示唆された。
Projection Mode Ulrasonic Microscopy for Cell-size Observation Peer-reviewed

Agus Indra Gunawan, Naohiro Hozumi, Tomohide Furuhashi, Sachiko Yoshida, Kazuto Kobayashi, Yoshifumi Saijo, Seiji Yamamoto

2013 Joint UFFC,EFTF and PFM Symposium(IEEE International Ultrasonics Symposium)　876-879　2013/07
Publisher: IEEE
DOI： 10.1109/ULTSYM.2013.0227 　

ISSN：1948-5719

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Ultrasonic microscope is a powerful tool for biological applications. This study is proposing new type of observation for internal structure of biological tissue without introducing contaminants. Glioma cells were cultured on a thin polystyrene film. The cultured space was subsequently enclosed between two films, with 15 mu m in gap distance. A focused ultrasonic beam, its frequency range being 200 - 400 MHz was transmitted from the rear side of the film. Microscopic images were acquired by mechanically scanning the transducer. The acoustic impedance mode observes the direct reflection from the interface between the plastic substrate and specimen. It reflects acoustic property in the vicinity of the interface between the substrate and specimen. It is highly quantitative but does not perfectly reflect the internal structure. The Projection mode observes the reflection from the interface on the surface of the second substrate that is placed with a certain gap. The beam travels twice through the tissue and comes back. Internal structure can clearly be seen with this observation mode, but quantitative analysis will not be easy because the internal structure through the thickness is not perfectly uniform. In both modes observation can be performed without introducing any contaminant to the tissue system.
ATP release to glutamate stimulation in rat cerebellar cortex correlated to the development of Purkinje cell dendrites and network formation Peer-reviewed

Naohiro Hozumi, Sachiko Yoshida, Kazuto Kobayashi, Yoshifumi Saijo, Seiji Yamamoto

the 2013 IEEE International Ultrasonics Symposium (IUS)　2013/07
Sound Field Analysis for Biological Acoustic Impedance Microscope for Its Precise Calibration Peer-reviewed

Naohiro Hozumi, Agus Indra Gunawan, Shota Kajima, Sachiko Yoshida, Kazuto Kobayashi, Yoshifumi Saijo, Seiji Yamamoto

2013 Joint UFFC,EFTF and PFM Symposium(IEEE International Ultrasonics Symposium)　1204-1207　2013/07
Publisher: IEEE
DOI： 10.1109/ULTSYM.2013.0310 　

ISSN：1948-5719
Ultrasonic Measurement of Microdisplacement Induced by Acoustic Radiation Force Peer-reviewed

Ryo Nagaoka, Takuya Izumi, Yosuke Komatsu, Kazuto Kobayashi, Yoshifumi Saijo

JAPANESE JOURNAL OF APPLIED PHYSICS　52　(7)　07HF21　2013/07
Publisher: IOP PUBLISHING LTD
DOI： 10.7567/JJAP.52.07HF21 　

ISSN：0021-4922

eISSN：1347-4065

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Quantitative evaluation of human skin aging is achieved by measuring the viscoelasticity of the skin. In the present study, microdisplacement induced by acoustic radiation force (ARF) is quantitatively measured by high-frequency ultrasonography (HFUS) and the result is confirmed by laser-Doppler velocimetry (LDV). Poly(vinyl alcohol) (PVA) with 1% cellulose particles was used as the biological phantom. A concave piezoelectric zirconate titanate (PZT) transducer with a diameter and focal length of 3 cm was used as an applicator to generate ARF. Microdisplacement at each depth of PVA was measured by the phased tracking method at 100 MHz of ultrasound with a repetition rate of 2000 Hz. When 80 tone-burst pulses were applied, the displacement measured by HFUS was 9 mu m and the same result was obtained by LDV. As the displacement at each depth of PVA is measurable using ARF and the HFUS system, the system could be applied to measuring the viscoelasticity of the layered structure of the human skin. (c) 2013 The Japan Society of Applied Physics
スクリーニング心エコーで発見された大動脈弁輪部膿瘍の一症例

藤原淳子, 小泉, 真澄, 遠藤, 洋一, 佐々木, 聖子, 大沼, 秀知, 三木, 俊, 西條, 西條芳文, 秋山, 正年, 齋木佳克

超音波医学　40　(3)　306-306　2013/05
Publisher: None
ISSN：1346-1176

eISSN：1881-9311
New Concept of Pathology - Mechanical Properties Provided by Acoustic Microscopy Peer-reviewed

Yoshifumi Saijo

Advances in Acoustic Microscopy and High Resolution Imaging: From Principles to Applications　187-206　2013/04/12
Publisher: Wiley-VCH
DOI： 10.1002/9783527655304.ch8 　
光音響イメージングによる軟骨-骨複合体における変形性膝関節症の評価

和泉拓哉, 長岡亮, 佐藤みか, 萩原嘉廣, 矢部裕, 西條芳文

超音波医学　40　(Suppl.)　S629-S629　2013/04
Publisher: (公社)日本超音波医学会
ISSN：1346-1176

eISSN：1881-9311
腱板付着部変性における酸化ストレスの関与

森川大智, 糸魚川善昭, 野尻英俊, 佐野博高, 井樋栄二, 西条芳文, 川崎隆之, 金子和夫, 清水孝彦

日本整形外科学会雑誌　87　(3)　S688-S688　2013/03
Publisher: (公社)日本整形外科学会
ISSN：0021-5325
Tele-Echographic Image Archiving System Using a Tablet Computer and a Virtual Probe

Sugita Norihiro, Yoshizawa Makoto, Abe Makoto, Homma Noriyasu, Yambe Tomoyuki, Saijo Yoshifumi

BME　51　M-10-M-10　2013
Publisher: Japanese Society for Medical and Biological Engineering
DOI： 10.11239/jsmbe.51.M-10 　

ISSN：1347-443X
Recent applications of acoustic microscopy for quantitative measurement of acoustic properties of soft tissues Peer-reviewed

Yoshifumi Saijo

Quantitative Ultrasound in Soft Tissues　291-314　2013/01/01
Publisher: Springer Netherlands
DOI： 10.1007/978-94-007-6952-6_12 　

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High resolution biomedical imaging using high frequency ultrasound is possible because both wavelength and beamwidth are inversely proportional to ultrasonic frequency. Scanning acoustic microscopy (SAM) uses 100MHz or higher frequency ultrasound. The spatial resolution achieved by a 100MHz and 1GHz ultrasound SAM are 15 and 1.5 μm, respectively. This level of detail enables cellular imaging. There are three unique features of SAM compared with other microscopy modalities such as optical, electron and atomic force microscopy. First, SAM can be applied for easy and simple histopathological examinations because it does not require special staining techniques. The contrast observed in SAM images depends on the acoustic properties (i.e., density, stiffness, and attenuation) and on the topographic contour of the tissue. Second, microscopic acoustic properties obtained with high frequency ultrasound can be used for assessing echo intensity and texture in clinical echography with lower frequency ultrasound. Third, SAM data can provide the basic data for assessing biomechanics of tissues and cells. Ultrasound is transmitted through a coupling medium and focused on the surface of the substrate. Transmitted ultrasound is reflected at both the surface of the biological material and the interface between the biological material and the substrate. The transducer receives the sum of these two reflections. The interference of these two reflections is determined by acoustic properties of the biological material. The interference signal as a function of the frequency depends on the thickness and sound speed of the sample. The interference signal as a function of the intensity depends on the amplitude of the surface reflection and attenuation of ultrasound propagating through the tissue. For bone, cartilage, tendon and cardiovascular tissues, microacoustic properties can provide important information on biomechanical properties. Biomechanic evaluation of these tissues is especially important for assessing the pathophysiology. Cells are considered to consist of viscoelastic materials and SAM has provided information on viscosity by ultrasonic attenuation estimates and information on elasticity by sound speed estimates. Instead of stretching cells or using atomic force microscopy for measuring biomechanical properties, SAM can be used to measure precise mechanical property distributions without contact to the cells. Thus, SAM provides a new paradigm of pathology that is based on the mechanical properties of is the object being imaged. Recent developments such as ultrasound speed microscopy, 3D ultrasound microscopy and high frequency array transducers may provide a clinically applicable SAM in the near future.
Three-dimensional imaging of the vasculature in chicken embryo by combination of ultrasonic and photoacoustic imaging Peer-reviewed

Mika Sato, Takuya Izumi, Yoshifumi Saijo, Yuji Watanabe, Harukazu Nakamura

IEEE International Ultrasonics Symposium, IUS　1532-1533　2013

DOI： 10.1109/ULTSYM.2013.0389 　

ISSN：1948-5719 1948-5727

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Vascular network is a good target for PA imaging with conventional 532 nm laser because the extinction coefficient is of red blood cell is high between 500 and 600 nm. Compared with US Doppler technique, PA imaging is superior for visualization of low speed blood flow in small vessels. Laser pulses were generated by a semiconductor diode laser with the wavelength of 532 nm, the pulse width of 3.4 ns. PA signal was received by a 50 MHz concave ultrasound transducer with a 1 mm hole in the central part to get through an optical fiber in order to concentrically align the light illumination and signal reception. Fertile chicken eggs were placed in a shallow dish after 3 days of incubation for easy observation with US and PA imaging. US imaging visualized overview of the whole body, especially, the vertebral column were clearly displayed. PA imaging visualized the heart and great vessels including aortic arch. This study showed the feasibility of US-PA combined imaging for observation of ex ovo chicken embryo and future application of the imaging modality in the developmental biology. © 2013 IEEE.
Acoustic characteristics of fatty and fibrotic liver measured by an 80-MHz and 250 MHz scanning acoustic microscopy Peer-reviewed

Tadashi Yamaguchi, Kenta Inoue, Kenji Yoshida, Satoki Zenbutsu, Hitoshi Maruyama, Jonathan Mamou, Kazuto Kobayashi, Yoshifumi Saijo

IEEE International Ultrasonics Symposium, IUS　393-396　2013

DOI： 10.1109/ULTSYM.2013.0102 　

ISSN：1948-5719 1948-5727

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Ultrasound imaging is ideally suited for early-stage assessments of liver steatosis and fibrosis, but conventional ultrasound B-mode images do not display quantitative tissue information because conventional ultrasound formation does not incorporate modeling of the complex interactions between ultrasound and liver tissue in normal and diseased states. In this study, two normal, two fatty, and two fibrotic rat livers were harvested, fixed, and embedded in paraffin. For each specimen, a single, central, 10-μm thin section was placed on a microscope slide and scanned in two dimensions (2-D) using a modified scanning acoustic microscope (AMS-50SI Honda Elec.) incorporating transducers operating at 80- and 250-MHz center frequencies. RF echo signals were digitized with 8-bit precision at a sampling frequency of 2-GHz. 2-D quantitative images of speed of sound (SOS) and attenuation were obtained (2.4 mm × 2.4 mm and 0.6 mm × 0.6 mm using the 80 and 250-MHz transducers, respectively) All images contained 300 × 300 pixels. The SOS and the attenuation values were calculated by averaging all values within 11 regions of interest (ROIs) from each 2-D image of all six livers. At 250-MHz, the SOS and attenuation values of normal, fatty, and fibrotic livers were 1622±32, 1591±20, 1700±44 m/s and 5.70±0.62, 8.38±0.51, 7.90±1.00 dB/mm respectively. The differences in SOS and attenuation values among liver types were greater at 250-MHz than at 80-MHz because of the improved spatial resolution, which allowed more-optimal placement of ROIs to contain only fatty or fibrotic tissue. © 2013 IEEE.
Speed of sound of fatty and fibrosis liver measured by 80-MHz and 250MHz scanning acoustic microscopy Peer-reviewed

Tadashi Yamaguchi, Kenta Inoue, Jonathan Mamou, Kazuto Kobayashi, Yoshifumi Saijo

Proceedings of Meetings on Acoustics　19　2013

DOI： 10.1121/1.4800375 　

ISSN：1939-800X

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Early detection of hepatitis is critical for proper patient management and improving disease prognosis. Ultrasound imaging is ideally suited for early-stage assessments, but conventional ultrasound images based on backscatter do not display quantitative tissue information because conventional ultrasound lacks essential modeling of the complex interaction between ultrasound and liver tissue in normal and diseased states. Therefore, speed-of-sound (SOS) measurements were obtained from three types of rat livers (normal, fatty, and fibrosis). Livers were harvested, fixed, and embedded in paraffin a single 10-μm thin section was obtained using a microtome and placed on a microscope slide. A scanning acoustic microscope incorporating transducers operating at 80-MHz and 250-MHz center frequencies was used to scan the 10-μm section. An adjacent 4-μm thin section was stained with H&amp E (normal and fatty livers) or Azan (fibrosis livers). The SOS measured with both transducers displayed the same trend: SOS in fatty liver was lower than in normal liver and SOS in fibrosis liver was higher than in normal liver. SOS differences were greater at 250 MHz because of the improved spatial resolution, which allowed choosing regionof-interests containing only fat or fibrosis tissue. These initial results also were used to correlate the pathologic state with the SOS. © 2013 Acoustical Society of America.
Multimodal ultrasound microscopy for biomedical imaging Peer-reviewed

Yoshifumi Saijo

Proceedings of Meetings on Acoustics　19　2013

DOI： 10.1121/1.4800342 　

ISSN：1939-800X

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Acoustic microscopy provides not only high resolution imaging but also basic data for interpreting clinical ultrasound images and information on biomechanics of the tissues. Multimodal ultrasound microscope is developed for quantitative measurement of sound speed of the tissue. The frequency dependent characteristics of the amplitude and phase of a single pulse deduce the tissue thickness and sound speed. Specific acoustic impedance and elastic bulk modulus are derived by the sound speed and density of the tissue. Ultrasound impedance microscope visualizes microscopic image of the tissue surface by just touching the probe to the tissue. The reflection from the interface between the tissue and plastic plate is obtained to visualize two-dimensional distribution of specific acoustic impedance of the tissue. The multimodal ultrasound microscope realized conventional C-mode, surface impedance mode, B-mode, 3D mode and combination of photoacoustic imaging. The series of the ultrasound measurements of gastric cancer, renal cancer, prostatic cancer, myocardial infarction, atherosclerosis, cartilage-bone complex and brain have provided important information for clinical ultrasound imaging and pathophysiology from the point of view of biomechanics. Development of higher frequency transducer or arrayed transducer with newest technologies would realize higher resolution imaging and easier handling. © 2013 Acoustical Society of America.
A New diagnostic feasibility for cardiomyopathy utilizing acoustic microscopy Peer-reviewed

Youichi Nakamura, Kengo, Fukushima Kusano, Kazufumi Nakamura, Kazuto Kobayashi, Naohiro Hozumi, Yoshifumi Saijo, Tohru Ohe

World Journal of Cardiovascular Diseases,2013,3,22-30 doi:10.4236/wjcd.2012.31006 Published Online January 2013　2013

DOI： 10.4236/wjcd.2012.31006 　
Validation of Echo-Dynamography by virtual color doppler echocardiography generated from phase contrast magnetic resonance angiography datasets Peer-reviewed

Takanori Kojima, Aiko Omori, Hiroyuki Nakajima, Takafumi Kurokawa, Takeyoshi Kameyama, Yoshifumi Saijo

Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS　105-108　2013

DOI： 10.1109/EMBC.2013.6609448 　

ISSN：1557-170X

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Echo-Dynamography (EDG) is a smart visualization technique in echocardiography in which two-dimensional distribution of blood flow vectors in cardiovascular system is deduced by applying fluid dynamics theories into Doppler velocity datasets. Previous validation studies such as numerical simulation of free jet model or model circulation were too simple to reproduce unstable and asymmetrical flow in left ventricle. In the present study, virtual color Doppler echocardiography is generated from PC-MRA (phase contrast magnetic resonance angiography) datasets. EDG is applied on virtual Doppler data and the blood flow vectors are compared with those of the original PC-MRA data. EDG-derived blood flow vectors showed similar pattern as the original PC-MRA data when blood flow velocity had high value. The errors were caused from underestimating the magnitude of vortex flow component in the flow field near the boundary of the left ventricular wall. The results also indicated that apical long axis view had small error compared with parasternal long axis view. Despite EDG method causes small errors, it provides important information on blood flow dynamics in most parts. © 2013 IEEE.
Relation between morphology of sebaceous glands inside human skin and viscoelastic properties Peer-reviewed

Ryo Nagaoka, Kazuto Kobayashi, Yoshifumi Saijo

Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS　1112-1115　2013

DOI： 10.1109/EMBC.2013.6609700 　

ISSN：1557-170X

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Three-dimensional ultrasound microscopy with the central frequency of 120 MHz made it possible to observe in vivo sebaceous glands at the deep part of the dermis at microscopic level. The deformation displacements were measured by an established testing device, and the viscoelasticity was estimated from the measured displacements and Voigt model. The occupancy, density or average size of sebaceous glands was compared with the viscoleasticity. There were three major findings in the comparisons. First, the occupancy of sebaceous gland showed negative correlation with the elasticity. Second, the density of sebaceous glands showed positive correlation with the viscosity. Third, the average size of sebaceous glands showed negative correlation with the viscosity. In conclusion, viscoelastic property of human skin is strongly influenced by the morphology of the sebaceous glands. © 2013 IEEE.
Ultrasonic and photoacoustic imaging of knee joints in normal and osteoarthritis rats. Peer-reviewed

Takuya Izumi, Mika Sato, Yutaka Yabe, Yoshihiro Hagiwara, Yoshifumi Saijo

Conf Proc 35th IEEE Eng Med Biol Soc　1116-1119　2013

DOI： 10.1109/EMBC.2013.6609701 　
The role of oxidative stress on degeneration of rotator cuff enthesis Peer-reviewed

Daichi Morikawa, Yoshiaki Itoigawa, Hidetoshi Nojiri, Hirotaka Sano, Eiji Itoi, Yoshifumi Saijo, Takayuki Kawasaki, Kazuo Kaneko, Takahiko Shimizu

Journal of Shoulder and Elbow Surgery　21　(12)　e25　2012/12

DOI： 10.1016/j.jse.2012.10.004 　

ISSN：1058-2746 1532-6500
A FOUR-CRITERION SELECTION PROCEDURE FOR ATHEROSCLEROTIC PLAQUE ELASTICITY RECONSTRUCTION BASED ON IN VIVO CORONARY INTRAVASCULAR ULTRASOUND RADIAL STRAIN SEQUENCES Peer-reviewed

Simon Le Floc'h, Guy Cloutier, Yoshifumi Saijo, Gerard Finet, Saami K. Yazdani, Flavien Deleaval, Gilles Rioufol, Roderic I. Pettigrew, Jacques Ohayon

ULTRASOUND IN MEDICINE AND BIOLOGY　38　(12)　2084-2097　2012/12
Publisher: ELSEVIER SCIENCE INC
DOI： 10.1016/j.ultrasmedbio.2012.07.021 　

ISSN：0301-5629

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Plaque elasticity (i.e., modulogram) and morphology are good predictors of plaque vulnerability. Recently, our group developed an intravascular ultrasound (IVUS) elasticity reconstruction method which was successfully implemented in vitro using vessel phantoms. In vivo IVUS modulography, however, remains a major challenge as the motion of the heart prevents accurate strain field estimation. We therefore designed a technique to extract accurate strain fields and modulograms from recorded IVUS sequences. We identified a set of four criteria based on tissue overlapping, RF-correlation coefficient between two successive frames, performance of the elasticity reconstruction method to recover the measured radial strain, and reproducibility of the computed modulograms over the cardiac cycle. This four-criterion selection procedure (4-CSP) was successfully tested on IVUS sequences obtained in twelve patients referred for a directional coronary atherectomy intervention. This study demonstrates the potential of the IVUS modulography technique based on the proposed 4-CSP to detect vulnerable plaques in vivo. (E-mail: Jacques.Ohayon@imag.fr) (c) 2012 World Federation for Ultrasound in Medicine & Biology.
小児人工肺動脈弁機能評価のための新しい右心系模擬循環回路開発

坪子侑佑, 鈴木, 一郎, 白石, 泰之, 山田, 昭博, 松尾, 諭志, 三浦, 英和, 西條, 西條芳文, 馮, 忠剛, 阿久津, 敏乃介, 梅津, 光生, 齋木, 佳克, 山家, 智之, 宮崎, 隆子, 山岸正明

人工臓器　41　(2)　S-148　2012/11
Publisher: None
ISSN：0300-0818

eISSN：1883-6097
極細形状記憶合金線維の多層化による人工心筋システムの改良

白石泰之, 早津, 幸弘, 秋山, 正年, 北野, 智哉, 山田, 昭博, 坪子, 侑佑, 中島, 博行, 庄内, 千紘, 柏, 公一, 西條, 西條芳文, 齋木, 佳克, 本間, 大, 山家智之

人工臓器　41　(2)　S-135　2012/11
Publisher: None
ISSN：0300-0818

eISSN：1883-6097
Application of a Telemedical Tool in an Isolated Island and a Disaster Area of the Great East Japan Earthquake Invited Peer-reviewed

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

IEICE Transactions on Communication　E95-B　(10)　3067-3073　2012/10
Publisher: The Institute of Electronics, Information and Communication Engineers
DOI： 10.1587/transcom.E95.B.3067 　

ISSN：0916-8516

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

Kazutoshi Kumagai, Hideyuki Koike, Ryo Nagaoka, Shingo Sakai, Kazuto Kobayashi, Yoshifumi Saijo

ULTRASOUND IN MEDICINE AND BIOLOGY　38　(10)　1833-1838　2012/10
Publisher: ELSEVIER SCIENCE INC
DOI： 10.1016/j.ultrasmedbio.2012.05.012 　

ISSN：0301-5629

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Observing the morphology of human skin is important in the diagnosis of skin cancer and inflammation and in the assessment of skin aging. High-frequency ultrasound imaging provides high spatial resolution of the deep layers of the skin, which cannot be visualized by optical methods. The objectives of the present study were to develop a three-dimensional (3-D) ultrasound microscope and to observe the morphology of normal human skin in vivo. A concave polyvinylidene fluoride transducer with a central frequency of 120 MHz was excited using an electric pulse generated by semiconductor switching. The transducer was scanned two-dimensionally by using two linear motors on the region-of-interest and the ultrasonic reflection was digitized with 2-GHz sampling. Consecutive B-mode images perpendicular to the skin surface were reconstructed to generate multiplanar reconstructed images and 3-D volume-rendering images clearly showing microstructures such as sebaceous glands and hair follicles. The 3-D ultrasound microscope could be used to successfully image the morphology of human skin noninvasively and may provide important information on skin structure. (E-mail: saijo@idac.tohoku.ac.jp) (C) 2012 World Federation for Ultrasound in Medicine & Biology.
腱板付着部変性における酸化ストレスの寄与

森川大智, 糸魚川善昭, 野尻英俊, 佐野博高, 井樋栄二, 西条芳文, 川崎隆之, 金子和夫, 清水孝彦

肩関節　37　(1)　248-248　2012/09
Publisher: (一社)日本肩関節学会
ISSN：0910-4461

eISSN：1881-6363
Telemedicine System Necessary in Disaster Areas Peer-reviewed

Norihiro Sugita, Makoto Yoshizawa, Hitoshi Kawata, Tomoyuki Yambe, Satoshi Konno, Yoshifumi Saijo, Makoto Abe, Noriyasu Homma, Shin-ichi Nitta

Proc. of the SICE Annual Conference 2012　1661-1664　2012/08/20
Chondrogenic, inflammatory and fibrotic process in pathology of idiopathic frozen shoulders Peer-reviewed

Y. Hagiwara, A. Ando, Y. Onoda, T. Takemura, T. Minowa, N. Hanagata, M. Tsuchiya, Y. Saijo, E. Itoi

Osteoarthritis and Cartilage　20　S247　2012/04
Publisher: Elsevier {BV}
DOI： 10.1016/j.joca.2012.02.411 　
Coexistence of fibrotic and chondrogenic process in the capsule of idiopathic frozen shoulders Peer-reviewed

Y. Hagiwara, A. Ando, Y. Onoda, T. Takemura, T. Minowa, N. Hanagata, M. Tsuchiya, T. Watanabe, E. Chimoto, H. Suda, N. Takahashi, H. Sugaya, Y. Saijo, E. Itoi

Osteoarthritis and Cartilage　20　(3)　241-249　2012/03

DOI： 10.1016/j.joca.2011.12.008 　

ISSN：1063-4584

eISSN：1522-9653

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Objective: To analyze changes in the capsule from idiopathic frozen shoulders and clarify their etiology. Materials and methods: Samples (the rotator interval capsule, middle glenohumeral ligament (MGHL), and inferior glenohumeral ligament (IGHL)) were collected from 12 idiopathic frozen shoulders with severe stiffness and 18 shoulders with rotator cuff tears as a control. The number of cells was counted and the tissue elasticity of the samples was calculated by scanning acoustic microscopy (SAM). The amount of glycosaminoglycan content was assessed by alcian blue staining. Gene and protein expressions related to fibrosis, inflammation, and chondrogenesis were analyzed by quantitative polymerase chain reaction (qPCR) and immunohistochemistry (IHC). Furthermore, the total genes of the two groups were compared by DNA microarray analysis. Results: The number of cells was significantly higher and the capsular tissue was significantly stiffer in idiopathic frozen shoulders compared with shoulders with rotator cuff tears. Staining intensity of alcian blue was significantly stronger in idiopathic frozen shoulders. Gene expressions related to fibrosis, inflammation, and chondrogenesis were significantly higher in idiopathic frozen shoulders compared with shoulders with rotator cuff tears assessed by both qPCR and DNA microarray analysis. Conclusion: In addition to fibrosis and inflammation, which used to be considered the main pathology of frozen shoulders, chondrogenesis is likely to have a critical role in pathogenesis of idiopathic frozen shoulders. © 2011 Osteoarthritis Research Society International.
Evaluation of the implant type tissue-engineered cartilage by scanning acoustic microscopy Peer-reviewed

Yoko Tanaka, Yoshifumi Saijo, Yuko Fujihara, Hisayo Yamaoka, Satoru Nishizawa, Satoru Nagata, Toru Ogasawara, Yukiyo Asawa, Tsuyoshi Takato, Kazuto Hoshi

JOURNAL OF BIOSCIENCE AND BIOENGINEERING　113　(2)　252-257　2012/02
Publisher: SOC BIOSCIENCE BIOENGINEERING JAPAN
DOI： 10.1016/j.jbiosc.2011.10.011 　

ISSN：1389-1723

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The tissue-engineered cartilages after implantation were nonuniform tissues which were mingling with biodegradable polymers, regeneration cartilage and others. It is a hard task to evaluate the biodegradation of polymers or the maturation of regenerated tissues in the transplants by the conventional examination. Otherwise, scanning acoustic microscopy (SAM) system specially developed to measure the tissue acoustic properties at a microscopic level. In this study, we examined acoustic properties of the tissue-engineered cartilage using SAM, and discuss the usefulness of this devise in the field of tissue engineering. We administered chondrocytes/atelocollagen mixture into the scaffolds of various polymers, and transplanted the constructs in the subcutaneous areas of nude mice for 2 months. We harvested them and examined the sound speed and the attenuation in the section of each construct by the SAM. As the results, images mapping the sound speed exhibited homogenous patterns mainly colored in blue, in all the tissue-engineered cartilage constructs. Contrarily, the images of the attenuation by SAM showed the variation of color ranged between blue and red. The low attenuation area colored in red, which meant hard materials, were corresponding to the polymer remnant in the toluidine blue images. The localizations of blue were almost similar with the metachromatic areas in the histology. In conclusion, the SAM is regarded as a useful tool to provide the information on acoustic properties and their localizations in the transplants that consist of heterogeneous tissues with various components. (C) 2011, The Society for Biotechnology, Japan. All rights reserved.
Engineering analysis of the effects of bulging sinuses in a newly designed pediatric pulmonary heart valve on hemodynamic function

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

JOURNAL OF ARTIFICIAL ORGANS　15　(1)　49-56　2012
Publisher: SPRINGER TOKYO
DOI： 10.1007/s10047-011-0609-1 　

ISSN：1434-7229

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

Takuya Izumi, Mika Sato, Yoshihiro Hagiwara, Yoshifumi Saijo

2012 IEEE INTERNATIONAL ULTRASONICS SYMPOSIUM (IUS)　1417-1420　2012
Publisher: IEEE
DOI： 10.1109/ULTSYM.2012.0354 　

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Osteoarthritis (OA) is the disease of articular cartilage which is a viscoelastic connective tissue with a smooth surface and serves as a cushion between joint bones. Among the diagnostic imaging modalities for knee OA including plain X-rays, CT, MRI and ultrasonography (US), US is quick, inexpensive and highest resolution imaging. Photoacoustic (PA) imaging is based on generation of the ultrasound by thermal expansion of the tissue when nano-second pulse laser is irradiated to the tissue. In the present study, PA system consisted of diode laser, ultrasonic concave transducer with the central frequency of 50 MHz, hollow optical fiber, amplifier, X-Y stage with stage controller to scan the sample, function generator, digitizer card with the sampling rate of 1 GHz and Windows-based PC was developed. The system can generate laser with the wavelength of 532 nm, the pulse width of 3.4 ns, the output power of 430 mu J and the repetition rate of 100 Hz. The hollow optical fiber used to transmit the laser enabled easy focusing by attaching lens cap on the fiber. The fiber was inserted through the center of the concave ultrasound transducer to be arranged coaxially. Cylindrical cartilage-bone complexes from adult male Sprague-Dawley rats were visualized by US and PA. In US image, strong echo is observed at the surfaces of the cartilage and subcartilage bone and low intensity echo is observed in the spongy bone. In PA image, strong signal is observed at the spongy bone which suggests high density of blood distribution. The power spectrum showed steep peak at 45 MHz in US and wide spectrum between 10 and 50 MHz in PA. The result suggests the possibility of PA imaging for detection of inflammatory change of the knee cartilage in clinical settings.
Elasticity of Artificial Skin by Measuring Displacement Induced by Acoustic Radiation Force Peer-reviewed

Ryo Nagaoka, Takuya Izumi, Kiyono Kubo, Kazuto Kobayashi, Yoshifumi Saijo

2012 IEEE INTERNATIONAL ULTRASONICS SYMPOSIUM (IUS)　1378-1381　2012
Publisher: IEEE
DOI： 10.1109/ULTSYM.2012.0344 　

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Wrinkled skin and sagging skin are closely related to both quantity and quality of collagen inside the dermis. Quantitative measurement of human skin elasticity is important because more interests are paid to skin aging in developed countries. The objectives of the present study are to generate micro-displacement of layered structure of artificial skin by acoustic radiation force (ARF) and to measure the displacement by phase analysis of high frequency ultrasound. A hemispherical PZT transducer with the central frequency of 1-MHz and the diameter of 30-mm was used as the applicator of ARF and a concave PVDF transducer with the central frequency of 100-MHz and the diameter of 4-mm was used as the sensor. Tone-burst pulse with the duration of 100 mu sec was input to the applicator. A time interval of Tone-burst pulse is 1000 mu sec. The relaxation time of living tissues is considered the order of a few seconds. The time interval is much smaller than the relaxation time. The pulse was synchronized with 100 MHz ultrasound of 3000 Hz repetition rate. With the position of the transducer fixed, the ultrasonic reflection was digitized with 1-GHz sampling and the RF signals were acquired at a 3000 Hz repetition rate. Obtained RF signal of scanning line was converted to M-mode image by a conventional image processing algorithm of echography. Strain of each layer was calculated by the displacement speed of each layer. The value of the collagen sponge layer is the highest, that of the silicone layer is the second and that of the mesh layer is the lowest. The method is applicable for in vivo elasticity measurement and it would provide significant information in human skin aging.
Sound Speed Measurement in Prostatic Cancer by Ultrasound Speed Microscope Peer-reviewed

Hideki Tanoue, Youji Urata, Yoshihiro Hagiwara, Yoshifumi Saijo

ACOUSTICAL IMAGING, VOL 31　31　331-337　2012
Publisher: SPRINGER
DOI： 10.1007/978-94-007-2619-2_32 　

ISSN：0270-5117

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The diagnostic sensitivity of transrectal ultrasonography (TRUS) of the prostate is not sufficient for definitive diagnosis of prostatic cancer. Prostatic cancer sometimes appears as low intensity echo but it sometimes appears as isointensity echo as normal prostate. Thus, precise ultrasonic information rather than ultrasonic intensity is needed for further diagnosis. In the present study, ultrasonic properties of prostatic tissue are measured by ultrasound speed microscope (USM) and malignancy of the tissue is discussed. The sample obtained by radical prostatectomy was fixed by formalin and sliced as approximately 5 mm in thickness. One slice without staining was used for USM observation and the neighboring slice with Elastica-Masson staining was used for optical microscopic observation for comparison. In the prostatic cancer tissue, the sound speed of the poorly differentiated adenocarcinoma was 1,570 +/- 8 m/s whereas as that of the well-differentiated adenocarcinoma was 1,660 +/- 30 m/s. The sound speed measurement clearly classified the tissue type of prostatic cancer. As the imaging resolution is anti-proportional to the ultrasonic frequency, USM provides ten times higher resolution compared with TRUS. The basic acoustic information obtained by USM is useful for understanding clinical echo findings by TRUS.
Observasion of Rat Brain Tumor Model and Its Quantitative Analysis by Acoustic Impedance Microscopy Peer-reviewed

N.Hozumi, S.Yoshida, K.Kobayashi, Y.Saijo, K.Miura, S.Yamamoto

2012 IEEE International Ultrasonics Symposium　2012
Publisher: IEEE
DOI： 10.1109/ULTSYM.2012.0593 　
Color Dependence of Photoacoustic Micro Imaging Peer-reviewed

Saijo Yoshifumi, Koike Hideyuki, Izumi Takuya, Miida Yusuke, Matsuura Yuji, Hozumi Naohiro

ACOUSTICAL IMAGING, VOL 31　31　323-329　2012

DOI： 10.1007/978-94-007-2619-2_31 　

ISSN：0270-5117
Echogenicity in transrectal ultrasound is determined by sound speed of prostate tissue components. Peer-reviewed

Hideki Tanoue, Yoshihiro Hagiwara, Kazuto Kobayashi, Yoshifumi Saijo

Conf Proc 34th IEEE Eng Med Biol Soc　460-463　2012

DOI： 10.1109/EMBC.2012.6345967 　
Evaluation of Vortex Flow in Left Ventricle by Echo-dynamography and Phase Contrast Magnetic Resonance Angiography Peer-reviewed

Takanori Kojima, Takeyoshi Kameyama, Hiroyuki Nakajima, Elena Khmyrova, Takafumi Kurokawa, Yoshifumi Saijo

2012 ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY (EMBC)　2676-2679　2012
Publisher: IEEE
ISSN：1557-170X

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Echo-dynamography (EDG) is a method for visualizing left ventricular (LV) blood flow based on cardiac Doppler measurement in which blood flow component perpendicular to the ultrasonic beam is deduced by applying fluid dynamics theories to two-dimensional (2D) distribution of blood flow component along the ultrasonic beam. EDG has been validated by numerical simulation and particle image velocimetry of model circulation. However, these validations were too simple to reproduce unstable and asymmetrical flow in a beating heart. In the present study, EDG is compared with three-directional (3D) blood flow distribution on the same plane obtained with phase contrast magnetic resonance angiography (PCMRA) for clinical validation. Moreover, the location and vorticity of the vortex flow in LV are measured quantitatively and the relation to echocardiographic parameters of systolic and diastolic functions is discussed. 3D components of blood flow on a plane were obtained with triple scans of the same plane with ECG trigger and breath holding; 1) phase encode (x-axis), 2) read out (y-axis) and 3) slice selection (z-axis). After the acquisition of MRA dataset, color Doppler dataset of the same plane was acquired and 2D velocity distribution was obtained with EDG in MATLAB programs. EDG and PCMRA showed similar velocity vector distribution and formation of LV vortex flow. The vortex at mid diastolic phase was strongly affected by early diastolic filling while the vortex at isometric contraction was affected by atrial filling. EDG gained a new insight on systolic-diastolic coupling from the view point of LV blood flow such as LV vortex formation.
Comparison of articular cartilage images assessed by high-frequency ultrasound microscope and scanning acoustic microscope. International-journal Peer-reviewed

Yoshihiro Hagiwara, Yoshifumi Saijo, Akira Ando, Yoshito Onoda, Hideaki Suda, Eiichi Chimoto, Kouki Hatori, Eiji Itoi

International orthopaedics　36　(1)　185-90　2012/01

DOI： 10.1007/s00264-011-1263-1 　

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PURPOSE: The purpose of this study was to compare images of a newly developed high-frequency ultrasound imaging system (HFUIS) and scanning acoustic microscope (SAM) and to calculate their Pearson product moment correlations with a view to applying HFUIS for clinical use. METHODS: Cylindrical cartilage-bone complexes from adult male Sprague-Dawley rats were obtained. The specimens were immersed in normal saline and scanned by HFUIS. Intensity by HFUIS was normalised by reflection from a steel plate at the same distance. After the scanning, specimens were fixed with paraformaldehyde, decalcified and embedded in paraffin. Thinly sliced tissues were prepared for SAM evaluation. After the scanning, three layers of articular cartilage (superficial, middle and deep) were independently evaluated and their relationships calculated. RESULTS: The superficial and deep layers indicated high relative intensity, whereas the middle layer showed nonhomogeneous relative intensity by HFUIS. A high relative intensity by HFUIS and high sound speed area by SAM had strong correlations (Pearson product moment correlation, superficial layer 0.704, middle layer 0.731). CONCLUSIONS: HFUIS produced high-resolution images of the articular cartilage and its intensity was strongly correlated with sound speed by SAM.
生体僧房弁モデルを用いた力学検討に基づく人工乳頭筋設計 Peer-reviewed

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

人工臓器　40　(2)　S138-S138　2011/10

ISSN：0300-0818
小児用新型肺動脈人工弁設計における最適化のための新しい設計の基礎検討 Peer-reviewed

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

人工臓器　40　(2)　S118-S118　2011/10

ISSN：0300-0818
日本発の人工臓器技術スマートアクチュエータを利用した人工心筋 Peer-reviewed

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

人工臓器　40　(2)　S26-S26　2011/10

ISSN：0300-0818
音響インピーダンス顕微鏡による脳腫瘍の観察と相関解析

鈴木貴也, 花井邦彦, 依田正之, 小林和人, 山本清二, 西條芳文, 穂積直裕, 吉田祥子

電気関係学会東海支部連合大会講演論文集(CD-ROM)　2011　ROMBUNNO.K4-7　2011/09/20
音響インピーダンス顕微鏡による培養細胞の3次元形状観察

花井邦彦, 鈴木貴也, 依田正之, 小林和人, 山本清二, 西條芳文, 穂積直裕, 吉田祥子

電気関係学会東海支部連合大会講演論文集(CD-ROM)　2011　ROMBUNNO.K4-6　2011/09/20
生物用音響インピーダンス顕微鏡による培養細胞の3次元形状観察

花井邦彦, 植村努, 鈴木貴也, 穂積直裕, 小林和人, 吉田祥子, 山本清二, 西條芳文

電気学会全国大会講演論文集　2011　(1)　186　2011/03/05
音響インピーダンス顕微鏡による脳腫瘍の観察とフーリエ解析

鈴木貴也, 植村努, 花井邦彦, 穂積直裕, 小林和人, 吉田祥子, 山本清二, 西條芳文

電気学会全国大会講演論文集　2011　(1)　185　2011/03/05
Location of flow axis line in the left ventricle and its interaction with local myocardial motion Peer-reviewed

Hiroyuki Nakajima, Shigeo Sugawara, Takeyoshi Kameyama, Haruna Tabuchi, Shigeo Ohtsuki, Motonao Tanaka, Yoshifumi Saijo

Journal of Echocardiography　9　(1)　24-29　2011/03

DOI： 10.1007/s12574-010-0067-4 　

ISSN：1349-0222 1880-344X

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Background: The interaction between local myocardial motion and blood flow dynamics should be assessed to evaluate left ventricular pump function. Methods: The contour map of the absolute value of blood flow velocity in the left ventricle (LV) was drawn. The ridgeline of the contour was defined as the "flow axis line". LV wall motion was assessed by the tracing endocardial border in consecutive B-mode images and by myocardial tissue velocity distribution obtained by the optical flow method. Results: The location of the main flow axis line was affected by the local myocardial movement in the short axis direction. The flow axis line method is superior to the previous investigations on two-dimensional blood flow analysis because it considered three-dimensional blood flow. Conclusions: The flow axis line represents not only intracardiac blood flow structure but also its interaction with the cardiac wall motion. © 2010 Japanese Society of Echocardiography.
Numerical Analysis of Effects of Measurement Errors on Ultrasonic-Measurement-Integrated Simulation Peer-reviewed

Kenichi Funamoto, Toshiyuki Hayase, Yoshifumi Saijo, Tomoyuki Yambe

IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING　58　(3)　653-663　2011/03
Publisher: IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
DOI： 10.1109/TBME.2010.2095418 　

ISSN：0018-9294

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

三井田佑輔, 小池秀幸, 西條芳文, 松浦祐司

電気関係学会東北支部連合大会講演論文集　2011　296-296　2011
Publisher: 電気関係学会東北支部連合大会実行委員会
DOI： 10.11528/tsjc.2011.0_296 　
High Frequency Ultrasound Imaging of Cartilage-Bone Complex Peer-reviewed

Y. Hagiwara, Y. Saijo, A. Ando, K. Kobayashi, A. Tanaka, N. Hozumi, K. Hatori, E. Itoi

ACOUSTICAL IMAGING, VOL 30　30　118-123　2011
Publisher: SPRINGER
DOI： 10.1007/978-90-481-3255-3_15 　

ISSN：0270-5117

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High frequency ultrasound microscope with central frequency of 100 MHz was developed. The system was capable of (1) conventional C-mode acoustic microscope imaging of thinly sliced tissue, (2) ultrasound impedance imaging of the surface of in vitro thick tissue and (3) 3D ultrasound imaging of inside of the in vitro tissue. In the present study, cylindrical cartilage-bone unit specimens were removed from rat knee joints and evaluated with the equipment. The resolution was enough to visualize the articular cartilage surface morphology and the subchondral bone. Compared with histological sections observed by optical microscope, it can also differentiate the non-calcified zone and calcified zone of the articular cartilage. High frequency ultrasound microscope will provide important information of the structural changes of the articular cartilage.
Visualization of Microvessels in Skin by Three-Dimensional Ultrasound Microscope Peer-reviewed

Y. Saijo, K. Kobayashi, N. Hozumi, A. Tanaka, S. Sakai

ACOUSTICAL IMAGING, VOL 30　30　107-112　2011
Publisher: SPRINGER
DOI： 10.1007/978-90-481-3255-3_13 　

ISSN：0270-5117

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A non-invasive imaging technique capable of visualizing microvessels through epidermis to subdermis has been strongly desired. A PVDF ultrasonic transducer with the central frequency of 100 MHz and the focal length of 3.2 mm was mechanically scanned over the objects by two linear servo motors controlled by a personal computer. A microvessel model was made of a tungsten wire with a diameter of 100-microns and placed in the water tank. The microvessel model was clearly visualized by 3D ultrasound microscope. In cases of skin imaging, conventional echo gel was used as the coupling medium between transducer and skin surface. In vivo 3D skin morphology was also clearly visualized. In dermis, a microvessel may be shown as small, round, lucent echo areas continuously observed in the serial sections. 3D structure of hair-follicle was also visualized from the skin surface to the bud of hair-follicle in dermis. The 3D ultrasound microscope noninvasively provides important information on the distribution of microvessels in skin.
IVUS Is Still Alive - Multi Parameter Analysis for Tissue Characterization of Coronary Atherosclerosis and Interpretation from Acoustic Microscopy Observation Peer-reviewed

Yoshifumi Saijo

2011 IEEE INTERNATIONAL ULTRASONICS SYMPOSIUM (IUS)　2005-2008　2011
Publisher: IEEE
DOI： 10.1109/ULTSYM.2011.0499 　

ISSN：1948-5719

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Is IVUS still alive in the era of OCT which provides higher resolution imaging? Besides easier usability, IVUS is superior to OCT from the point of view of tissue characterization of coronary atherosclerosis. In the present study, multi parameter analysis such as integrated backscatter (IB), Virtual Histology (VH), strain rate imaging and newly developed method named "attenuation imaging" are compared and discussed the interpretation by acoustic microscopy observations. RF signal was obtained from commercial available IVUS systems by the use of fast digitizer card with the sampling frequency of 400 MHz. IB-IVUS image was generated by integrating 128 points of absolute value of RF signal. Conventional IVUS and IB-IVUS show homogeneous fibrous plaque but the deeper region is represented as fibrofatty plaque by VH-IVUS, softer region in the strain rate imaging and low attenuation in the attenuation imaging. Acoustic microscopy observation showed the fibrofatty region as lower attenuation than that of the fibrous tissue. Multi parameter analysis showed the region of soft plaque more clearly than conventional IVUS. As ultrasound reflects mechanical properties of the tissue, IVUS provides important information which was not provided by OCT.
Color-dependent photoacoustic effect for biomedical functional imaging Peer-reviewed

Yoshifumi Saijo, Hideyuki Koike, Takuya Izumi, Yusuke Miida, Yuji Matsuura, Naohiro Hozumi

Proceedings of Forum Acusticum　45-48　2011

ISSN：2221-3767

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The photoacoustic (PA) effect is a conversion of the light to acoustic waves due to absorption and localized thermal excitation. PA imaging possibly becomes biomedical functional imaging because optical absorption is closely associated with physiological properties, such as hemoglobin concentration and oxygen saturation. In the present study, color-dependent PA effect was examined for basis of biomedical functional imaging. US imaging clearly visualized the surface shape of the flat cable while PA imaging showed color-dependent heterogeneous reflections. The result suggests that the combination of US and PA imaging may become biomedical functional imaging when only a single wavelength of laser beam is used for PA excitation.
Imaging of Sebaceous Glands of Human Skin by Three-dimensional Ultrasound Microscopy and Its Relation to Elasticity Peer-reviewed

Kazutoshi Kumagai, Hideyuki Koike, Yukina Kudo, Ryo Nagaoka, Kiyono Kubo, Kazuto Kobayashi, Yoshifumi Saijo

2011 ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY (EMBC)　7199-7202　2011
Publisher: IEEE
ISSN：1557-170X

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High frequency ultrasound imaging has realized high resolution in vivo imaging of the biological tissues at a microscopic level. Human skin structure, especially sebaceous glands at the deep part of the dermis, was observed by three-dimensional ultrasound microscopy with the central frequency of 120 MHz. The visco-elasticity and surface sebum level of the observed region were measured by established testing devices. Both sebaceous glands density and surface sebum level were higher in cheek than those in forearm. The viscosity of forearm was lower than that of cheek. These results suggest that sebaceous glands may act as cushions of the skin besides their classical role of secreting sebum and some hormones. High frequency ultrasound imaging contributes to the evaluation of human skin aging.
Ultrasonic tissue characterization of prostate biopsy tissues by ultrasound speed microscope. Peer-reviewed

Hideki Tanoue, Yoshihiro Hagiwara, Kazuto Kobayashi, Yoshifumi Saijo

Conf Proc 33rd IEEE Eng Med Biol Soc　8499-8502　2011

DOI： 10.1109/IEMBS.2011.6092097 　
Reversibility of immobilization-induced articular cartilage degeneration after remobilization in rat knee joints Peer-reviewed

Akira Ando, Hideaki Suda, Yoshihiro Hagiwara, Yoshito Onoda, Eiichi Chimoto, Yoshifumi Saijo, Eiji Itoi

Tohoku Journal of Experimental Medicine　224　(2)　77-85　2011

DOI： 10.1620/tjem.224.77 　

ISSN：0040-8727

eISSN：1349-3329

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Joint immobilization is commonly used for the treatment of joint injuries, but it causes articular cartilage degeneration. The purpose of this study was to clarify the reversibility of immobilization-induced articular cartilage degeneration using rat knee joints. Immobilization of rat knee joints induces atrophic changes in the non-contact area, loss of chondrocytes in the contact area, and hypertrophy of chondrocytes in the transitional area of the articular cartilage. The unilateral knee joints of adult male rats were rigidly immobilized at 150° of flexion with a plate and screws for 1, 2, and 4 weeks. After the experimental periods, the fixation devices were removed and the rats moved freely for 16 weeks. Sham-operated rats were used as a control. Sagittal sections at medial midcondylar regions of the knee were assessed with histological and histomorphometric methods. Mechanical properties were assessed by measuring the sound speed with scanning acoustic microscope. Reduction of cartilage proteoglycan in the non-contact area was almost reversible, but hypertrophy of chondrocytes in the transitional area and loss of chondrocytes in the contact area were irreversible even at 1-week immobilization-remobilization group. Sound speed of the articular cartilage in the contact area was not restored. These results indicate that atrophic changes through decreased mechanical stress in the non-contact area were reversible, but loss of chondrocytes and hypertrophy of chondrocytes in the contact and transitional areas through increased mechanical stress by rigid immobilization were irreversible after remobilization. Clinicians should be aware that even a short-term rigid immobilization could cause irreversible articular cartilage damage. © 2011 Tohoku University Medical Press.
棘上筋腱骨停止部の変性と物理特性超音波顕微鏡による計測

佐野博高, 糸魚川善昭, 篠崎晋久, 迫間巧将, 山本宣幸, 井樋栄二, 西條芳文, Uhthoff Hans K., Trudel Guy

肩関節　35　(1)　51-51　2010/09
Publisher: (一社)日本肩関節学会
ISSN：0910-4461

eISSN：1881-6363
Enthesisの基礎構造と機能棘上筋腱骨付着部の物理特性超音波顕微鏡による計測 Peer-reviewed

佐野博高, 服部弘之, 峯田光能, 井樋栄二, 西條芳文

日本整形外科学会雑誌　84　(9)　567-570　2010/09
電子診療鞄の展開と評価 Peer-reviewed

杉田典大, 吉澤誠, 山家智之, 西條芳文, 金野敏, 仁田新一

日本遠隔医療学会雑誌　6　(2)　207-210　2010/09
Publisher: None
ISSN：1880-800X
Effect of Measurement Error on Ultrasonic-Measurement-Integrated Simulation of Blood Flow in an Aortic Aneurysm

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

Proceedings of the 13th International Symposium of 2007 Tohoku University Global COE Program “Global Nano-Biomedical Engineering Education and Research Network Centre”　80-83　2010/08/04
棘上筋腱骨停止部の組織学的変性と物理特性超音波顕微鏡による計測 Peer-reviewed

佐野博高, 糸魚川善昭, 篠崎晋久, 迫間巧将, 山本宣幸, 井樋栄二, 西條芳文, TrudelGuy, UhthoffHans K

日本整形外科学会雑誌　84　(8)　S1222-S1222　2010/08
Publisher: None
ISSN：0021-5325
Effect of deposition time on film thickness and their properties for hydrothermally-grown epitaxial KNbO3 thick films Peer-reviewed

Mutsuo Ishikawa, Hiro Einishi, Mitsumasa Nakajima, Tomohito Hasegawa, Takeshi Morita, Yoshifumi Saijo, Minoru Kurosawa, Hiroshi Funakubo

Japanese Journal of Applied Physics　49　(7)　2010/07

DOI： 10.1143/JJAP.49.07HF01 　

ISSN：0021-4922 1347-4065

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Deposition behavior and the crystal structure of the epitaxial KNbO3 films, grown at 240 =C on (100)cSrRrO3 == (100)SrTiO3 substrates using hydrothermal method, as well as their ferroelectric and piezoelectric properties were systematically investigated. Film deposition was detected to have begun after 2 h from the start, and the thickness increased with increasing the deposition time up to 4 h, but contrary decreased after 9 h due to the etching by KOH. X-ray diffraction (XRD) patterns of the films were basically the same regardless of the deposition time. However, the films deposited for 15 h introduces large amount of voids than those for 2 h. Ferroelectric and piezoelectric response of the films deposited for 2 and 15 h were measured to have similar film thickness, but the maximum applied electric field for the 2-h films was twice as that for the 15-h ones. The prototype ultrasonic transducer was fabricated using the KNbO3 films, which were deposited by hydrothermal method at 240 =C for 3 h, and proved to be able to transmit and receive ultrasonic signals above 90MHz in degassed water. © 2010 The Japan Society of Applied Physics.
Effect of estrogen on tissue elasticity of the ligament proper in rabbit anterior cruciate ligament: measurements using scanning acoustic microscopy. Peer-reviewed

Hattori Koshi, Sano Hirotaka, Komatsuda Tatsuro, Saijo Yoshifumi, Sugita Takehiko, Itoi Eiji

J Orthop Sci　15　(4)　584-588　2010/07

DOI： 10.1007/s00776-010-1474-0 　

ISSN：0949-2658
Brief Effect of Acupuncture on the Peripheral Arterial System of the Upper Limb and Systemic Hemodynamics in Humans Peer-reviewed

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

JOURNAL OF ALTERNATIVE AND COMPLEMENTARY MEDICINE　16　(7)　707-713　2010/07
Publisher: MARY ANN LIEBERT, INC
DOI： 10.1089/acm.2009.0355 　

ISSN：1075-5535

eISSN：1557-7708

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Background: Pulse diagnosis of the peripheral artery is an important technique in Traditional Chinese Medicine, where, in acupuncture therapy, the treatment is adjusted according to the observed changes of the pulse. We investigated the change of blood flow in the peripheral artery and the cardiac index during acupuncture treatment. Objectives: The aim of this study is to explore the effect of acupuncture on radial and brachial artery blood flow volume and the cardiac index in healthy subjects. Methods: Eighteen (18) healthy volunteers were enrolled. Acupuncture was performed bilaterally on LR-3 with manual rotation of the needles. The blood pressure and heart rate were measured at rest and 180 seconds after acupuncture. Radial and brachial artery blood flow volume was monitored continuously by an ultrasound with an echo-tracking system. Cardiac index was measured by impedance cardiography. The hemodynamic parameters were measured before, during, and 30, 60, 180 seconds after acupuncture. Results: The peripheral artery blood flow volume decreased significantly during acupuncture (radial; p<0.01, brachial; p<0.05) but increased at 180 seconds after acupuncture (radial; p<0.05, brachial; p<0.05) compared with before acupuncture. The cardiac index did not change significantly after acupuncture, but systemic vascular resistance index significantly decreased (p<0.05). Conclusions: The present study showed that radial and brachial artery blood flow volume decreased immediately during acupuncture on LR-3 acupoint, but increased at 180 seconds after acupuncture. This reaction is attributed to the change in peripheral vascular resistance.
A-V-V-Aパターンでのみ誘発されたnarrow QRS tachycardiaの1例

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

Journal of Arrhythmia　26　(Suppl.)　279-279　2010/04
Publisher: (一社)日本不整脈心電学会
ISSN：1880-4276

eISSN：1883-2148
3次元逆畳込による生物用音響インピーダンス顕微鏡の収差補正と評価

植村努, 鈴木貴也, 花井邦彦, 穂積直裕, 小林和人, 吉田祥子, 山本清二, 西條芳文

電気学会全国大会講演論文集　2010　(1)　152　2010/03/05
RADIAL ARTERY HEMODYNAMIC CHANGES RELATED TO ACUPUNCTURE Peer-reviewed

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

EXPLORE-THE JOURNAL OF SCIENCE AND HEALING　6　(2)　100-105　2010/03
Publisher: ELSEVIER SCIENCE INC
DOI： 10.1016/j.explore.2009.12.001 　

ISSN：1550-8307

eISSN：1878-7541

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

Minami Ogawa, Yoshifumi Saijo, Kazuto Kobayashi, Takahiro Iwamoto, Hideyuki Koike, Kazutoshi Kumagai, Akira Tanaka, Makoto Yoshizawa

5th International Symposium on Medical, Bio- and Nano-Electronics　2010/02
Ultrasonic Measurement of Micro-acoustic Properties of the Biological Soft Materials Peer-reviewed

Yoshifumi Saijo

Advanced Ultrasonic Methods for Material and Structure Inspection　89-113　2010/01/27
Publisher: ISTE
DOI： 10.1002/9780470612248.ch3 　
超音波顕微鏡を利用したラット下顎頭軟骨弾性の経時的変化

羽鳥弘毅, 萩原嘉廣, 西條芳文, 安藤晃, 伊奈慶典, 安藤浩二, 白石成, 佐藤奨, 佐々木啓一

日本補綴歯科学会誌　2　(1)　E19-E19　2010/01
Publisher: (公社)日本補綴歯科学会
ISSN：1883-4426

eISSN：1883-6860
Effect of measurement error on ultrasonic-measurement-integrated simulation of blood flow in an aortic aneurysm Peer-reviewed

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

IFMBE Proceedings　31　1652-1655　2010

DOI： 10.1007/978-3-642-14515-5_420 　

ISSN：1680-0737

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

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

IFMBE Proceedings　31　469-472　2010

DOI： 10.1007/978-3-642-14515-5_120 　

ISSN：1680-0737

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Myocardial infarction (MI) may cause left ventricular aneurysms (LVAs) as the long-term and obsolete complications. Following MI, the scar will replace the necrotic lesion within a few weeks. As a result, a portion of the left ventricular free wall protrudes, which leads to appearance of LVAs. The three dimensional echocardiography, the computed tomography and the magnetic resonance imaging (MRI) are the most effective tools to diagnose the left ventricular volumetric function and its wall motion. And the primary choice to treat LVAs is surgical therapy, which is called the left ventricular reconstructive surgery (LVRS). The LVRS such as Dor procedure is performed to resume the left ventricular shape and its original myocardial fibre orientation as much as possible. Furthermore, we also have to consider the location of the couple of papillary muscle in order to maintain the mitral valvular functions. When the ventricle dilates due to the obsolete MI, the papillary muscles might be displaced away from the mitral valvular annulus, leading to decreased coaptaion of the mitral leaflets and mitral regurgitation. As the clinical status, the surgeons establish the surgical planning of LVRS according to their design, evidence and experience base on the diagnostic imaging, which is difficult to estimate the postoperative cardiac function and structure quantitatively. The purpose of this study was to support surgeons to examine more quantitative surgical strategies by dint of engineering approach as fabrication of diseased ventricular tangible elastic model and numerical analyses in each patient prior to the treatment. Then we developed a prototyping method of fabrication for elastic ventricular models by the normal sequence of MRI data, which could show the identical and quantitative representation of diagnostic imaging. It is anticipated that these methods could realise the quantitative images and expressions as well as the intercommunity to the strategy of surgical therapy to reduce the patients' risk. As the results: a) An engineering method for the three-dimension reconstruction of diseased ventricular configuration from MRI in cardiac end-systole and end-diastole was established. By using of this method, the evaluation of ventricular motive displacement could be realized and farther researches could be performed base on the reconstructed data. b) A distinctive short-term process for fabricating tangible elastic diseased ventricular model was established. The models could give the surgeons a tangible image of the diseased ventricular shape. On the other hand, preoperative investigations of ventricular blood volume and morphological characteristic could be accomplished. c) The presentation of ventricular wall stress distribution around the diseased lesion was simulated by the finite element method (FEM). According to the result of numerical analyses, it was indicated that the stress distribution was greatly related with the ventricular shape. Moreover, the boundary between the diseased lesion and normal portion, which is important for the decision of surgical position, was shown distinctly. © 2010 International Federation for Medical and Biological Engineering.
Cross-sectional observation of rat brain tumor model and its quantitative analysis by newly proposed acoustic microscope Peer-reviewed

Naohiro Hozumi, Takaya Suzuki, Tsutomu Uemura, Katsutoshi Miura, Kazuto Kobayashi, Sachiko Yoshida, Masayuki Nagao, Yoshifumi Saijo, Seiji Yamamoto

International Journal of Computer Assisted Radiology and Surgery　5　(1)　S317-S318　2010
A Mobile Communications System for Home-Visit Medical Services: The Electronic Doctor's Bag Peer-reviewed

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

2010 ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY (EMBC)　5496-5499　2010
Publisher: IEEE
DOI： 10.1109/IEMBS.2010.5626577 　

ISSN：1557-170X

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In the present study, "Electronic Doctor's Bag" which is a tele-healthcare tool for home-visit medical service using the mobile communications environment has been proposed and evaluated by preliminary experiments. It was shown that its basic function was sufficiently evaluated by a few doctors and nurses but further improvement in portability and operability is required on the basis of much more opinions of medical and nursing professionals.
モバイル通信を用いた電子診療鞄の開発 Peer-reviewed

吉澤誠, 山家智之, 西條芳文, 金野敏

Japanese Journal of Telemedicine and Telecare　5　(2)　182-183　2009/10
Acoustic microscopy: latest developments and applications. Invited Peer-reviewed

Saijo Y

Imaging in Medicine　1　(1)　47-63　2009/10
3次元逆畳込による生物用音響インピーダンス顕微鏡の収差補正

植村努, 中野愛子, 花井邦彦, 穂積直裕, 小林和人, 吉田祥子, 山本清二, 西條芳文

電気関係学会東海支部連合大会講演論文集(CD-ROM)　2009　ROMBUNNO.O-232　2009/09/07
生体組織用音響インピーダンス顕微鏡によるラットの脳腫瘍モデルの観察と定量解析

鈴木貴也, 植村努, 穂積直裕, 小林和人, 吉田祥子, 山本清二, 西條芳文

電気関係学会東海支部連合大会講演論文集(CD-ROM)　2009　ROMBUNNO.O-231　2009/09/07
Hemodynamic response with an artificial myocardial assistance in chronic animal, examination Peer-reviewed

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

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

DOI： 10.1007/978-3-642-03887-7-80 　
Analysis of baroreflex sensitivity during undulation pump ventricular assist device support. Peer-reviewed

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

Artif Organs　33　(7)　561-565　2009/07

DOI： 10.1111/j.1525-1594.2009.00738.x 　
Reproduction of Blood Flow Field by Numerical Simulation Integrated with Ultrasonic Measurement with Noise

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

Proceedings of the ASME 2009 Summer Bioengineering Conference　2009/06/18

DOI： 10.1115/SBC2009-206596 　
Effect of Aliasing on Ultrasonic-Measurement-Integrated Simulation of Three-Dimensional Unsteady Blood Flow

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

Proceedings of the 10th International Symposium of 2007 Tohoku University Global COE Program “Global Nano-Biomedical Engineering Education and Research Network Centre”　18-19　2009/04/17
Assessment of synchronization measures for effective ventricular support by using the shape memory alloy fibred artificial myocardium in goats. Peer-reviewed

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

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

DOI： 10.1109/IEMBS.2009.5333627 　
3次元形状観察機能を有する生物用音響インピーダンス顕微鏡

中野愛子, 植村努, 穂積直裕, 吉田祥子, 小林和人, 山本清二, 西條芳文

電気学会全国大会講演論文集　2009　(1)　155　2009/03/17
生体組織用音響インピーダンス顕微鏡における音場計算

植村努, 中野愛子, 高山靖章, 武本諒太, 穂積直裕, 小林和人, 吉田祥子, 山本清二, 西條芳文

電気学会全国大会講演論文集　2009　(1)　158　2009/03/17
Ultrasonic intensity microscopy for imaging of living cells. International-journal Invited Peer-reviewed

Yoshihiro Hagiwara, Yoshifumi Saijo, Akira Ando, Eiichi Chimoto, Hideaki Suda, Yoshito Onoda, Eiji Itoi

Ultrasonics　49　(3)　386-8　2009/03

DOI： 10.1016/j.ultras.2008.10.013 　

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Ultrasound intensity microscopy was developed for in vivo imaging. This paper describes the preliminary results obtained using 300 MHz ultrasound intensity microscopy for in vitro characterization of cell cultures. The novelty of the approach lies in the fact that it allows remote, non-contact and disturbance-free imaging of cultured synovial cells and the changes in the cells' properties due to external stimulants such as transforming growth factor beta-1 (TGF-beta1). The intensity imaging method has potential for extracting mechanical cell properties and monitoring the effects of drugs. Ultrasound propagates through a thin specimen such as cultured cells and is reflected at the interface between the specimen and substrate. A two-dimensional distribution of the ultrasonic intensity, which is closely related to the mechanical properties, is visualized to analyze cell organs, such as the nucleus at the central part and the cytoskeleton at the peripheral zone. After stimulation with TGF-beta1, the ultrasonic intensity at the actin zone was significantly increased compared with the control.
Changes of articular cartilage after immobilization in a rat knee contracture model. International-journal Peer-reviewed

Yoshihiro Hagiwara, Akira Ando, Eiichi Chimoto, Yoshifumi Saijo, Kaori Ohmori-Matsuda, Eiji Itoi

Journal of orthopaedic research : official publication of the Orthopaedic Research Society　27　(2)　236-42　2009/02

DOI： 10.1002/jor.20724 　

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The objective was to determine the changes of articular cartilage of the knee joint during immobilization in a rat model. The knee joints of adult male rats were immobilized at 150 degrees of flexion using an internal fixator for 3 days, and 1, 2, 4, 8, and 16 weeks. The articular cartilage from the medial midcondylar region of the knee was obtained, divided into three areas (non-contact area, transitional area, contact area), and in each area, a degree of degeneration was evaluated by gross observation, histomorphometric grading, and measurements of thickness and number of chondrocytes. Elasticity of the articular cartilage was estimated by measuring the sound speed with use of scanning acoustic microscopy. Degeneration of the articular cartilage was mainly observed in the contact and transitional areas. Matrix staining intensity by safranin-O and number of chondrocytes were decreased in these two areas. The thickness of the articular cartilage in the non-contact and contact areas was unchanged, but it was increased in the transitional area. Decrease in sound speed was observed in the transitional area of both the femoral and tibial cartilage, indicating the softening of the articular cartilage. The changes of articular cartilage became obvious as early as 1 week after immobilization. These changes may be due to a lack of mechanical stress or a lack of joint fluid circulation during immobilization. Although we do not know the reversibility of these changes of articular cartilage, early mobilization is preferable to avoid these cartilage changes.
超音波顕微鏡を利用したラット臼歯歯根膜弾性の経時的変化

佐藤奨, 萩原嘉廣, 西條芳文, 安藤晃, 伊奈慶典, 安藤浩二, 白石成, 羽鳥弘毅, 佐々木啓一

日本補綴歯科学会誌　1　(1)　E41-E41　2009/01
Publisher: (公社)日本補綴歯科学会
ISSN：1883-4426

eISSN：1883-6860
Preliminary Study on Interactive Control for the Artificial Myocardium by Shape Memory Alloy Fibre Peer-reviewed

R. Sakata, Y. Shiraishi, Y. Sato, Y. Saijo, T. Yambe, Y. Luo, D. Jung, A. Baba, M. Yoshizawa, A. Tanaka, T. K. Sugai, F. Sato, M. Umezu, S. Nitta, T. Fujimoto, D. Homma

IFMBE Proceedings　23　1409-1412　2009

DOI： 10.1007/978-3-540-92841-6_348 　

ISSN：1680-0737

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The authors have been developing a sophisticated artificial myocardium for the treatment of heart failure, which is capable of supporting contractile function from the outside of the ventricle. The purpose of this study was to construct the control methodology of functional assistance by an artificial myocardium using small active mechanical elements composed of shape memory alloy fibres (Biometal). In order to achieve a sophisticated mechanical support by using shape memory alloy fibres, the diameter of which was 100 microns, the mechanical response of the myocardial assist device unit was examined by using PID (Proportional-Integral-Derivative) control method. Prior to the evaluation of dynamic characteristics, the relationship between strain and electric resistance of the shape memory alloy fibre and also the inditial response of each unit were obtained in the electrical bridge circuit. The component for the PID control was designed for the regulation of the myocardial contractile function. An originally-designed RISC microcomputer was employed and the input or output signals were controlled by pulse width modulation method in respect of displacement controls. Consequently, the optimal PID parameters were confirmed and the fibrous displacement was successfully regulated under the different heat transfer conditions simulating internal body temperature as well as bias tensile loading. Then it was indicated that this control methodology could be useful for more sophisticated ventricular passive or active restraint by using the artificial myocardium on physiological demand interactively.
Acoustic microscopy - Beyond high resolution imaging Peer-reviewed

Yoshifumi Saijo

Proceedings - IEEE Ultrasonics Symposium　2009

DOI： 10.1109/ULTSYM.2009.5441892 　

ISSN：1051-0117

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There are three major objectives of acoustic microscopy in medicine and biology 1) rapid examination of histopathology without staining or slicing, 2) search for the origin of echo in clinical ultrasound imaging and 3) novel approach to the pathophysiology from biomechanical point of view. The design of our newest acoustic microscopy is flexible to realize multimode ultrasound microscope with conventional C-mode, surface impedance mode, B-mode and reconstructed 3D mode. Measurements of microscopic acoustic properties in gastric cancer, renal cancer, myocardial infarction, atherosclerosis, tendon, cartilage and brain have provided useful information not limited in the field of medical ultrasound but also in the field of biomechanics especially in cardiology and orthopedic surgery. Passions of biomedical researchers to find the new horizons in pathophysiology are important for future progression of acoustic microscopy. ©2009 IEEE.
First Trial of the Chronic Animal Examination of the Artificial Myocardial Function Peer-reviewed

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

13TH INTERNATIONAL CONFERENCE ON BIOMEDICAL ENGINEERING, VOLS 1-3　23　(1-3)　2268-+　2009
Publisher: SPRINGER
ISSN：1680-0737

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

Uemura T, Suzuki T, Hanai, K, Hozumi, N, Yoshida, S, Kobayashi, K, Yamamoto, S, Saijo, Y

Ultrasonics Symposium　10.1109/ULTSYM.2009.5441436　1518-1521　2009
Numerical Experiment of Transient and Steady Characteristics of Ultrasonic-Measurement-Integrated Simulation in Three-Dimensional Blood Flow Analysis Peer-reviewed

Kenichi Funamoto, Toshiyuki Hayase, Yoshifumi Saijo, Tomoyuki Yambe

ANNALS OF BIOMEDICAL ENGINEERING　37　(1)　34-49　2009/01
Publisher: SPRINGER
DOI： 10.1007/s10439-008-9600-2 　

ISSN：0090-6964

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

Hiroaki Kijima, Hiroshi Minagawa, Yoshifumi Saijo, Hirotaka Sano, Tatsuru Tomioka, Nobuyuki Yamamoto, Yoichi Shimada, Kyoji Okada, Eiji Itoi

JOURNAL OF ORTHOPAEDIC SCIENCE　14　(1)　62-67　2009/01
Publisher: SPRINGER TOKYO
DOI： 10.1007/s00776-008-1283-x 　

ISSN：0949-2658

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The purpose of this study was to determine the elasticity of the coracoacromial ligament in shoulders with and without rotator cuff tears. The coracoacromial ligaments from 20 cadaveric shoulders (average patient age 79.5 years; 8 men, 12 women) were divided into six portions - three portions (acromial, central, and coracoid) in two layers (superficial and deep). A total of 120 samples were studied. First, the samples were classified by the collagen fiber orientation into three degeneration patterns: wavy, straight, irregular. For each pattern, the tissue sound speed, which shows a positive correlation with elasticity, was measured with scanning acoustic microscopy. Next, the samples were divided into three groups: 60 samples from shoulders with rotator cuff tears (RCT group), 30 samples from shoulders with an intact rotator cuff and a subacromial spur (spur group), and 30 samples from shoulders with an intact rotator cuff without a subacromial spur (control group). All shoulders with rotator cuff tears had subacromial spurs. The tissue sound speed and the histological findings were compared among the groups. The sound speeds in the wavy, straight, and irregular patterns were 1592 +/- 17.2 m/s (mean +/- SD), 1626 +/- 28.0 m/s, and 1607 +/- 29.8 m/s, respectively (P < 0.0001). The sound speed in the straight pattern was higher than that in the wavy pattern (P < 0.0001), and that in the irregular pattern was lower than that in the straight pattern (P = 0.0023). The RCT group and the spur group had more straight patterns (P = 0.0002) and fewer wavy patterns (P < 0.0001) than did the control group. Significant differences in the sound speed were observed between the groups (P < 0.0001): 1596 +/- 19.1 m/s in the control group, 1630 +/- 31.5 m/s in the spur group, 1612 +/- 28.6 m/s in the RCT group. The coracoacromial ligament in shoulders with rotator cuff tears shows higher elastic modulus than in age-matched normal shoulders due to degeneration of the ligament.
Quantitativeevaluation of the baroreflex sensitivity of an artery Peer-reviewed

T. Yambe, Y. Shiraishi, Y. Saijo, H. Liu, S. Nitta, K. Imachi, A. Baba, T. Yamaguchi, S. Sugawara, Y. Katahira, N. Ohsawa, Y. Mibiki, M. Watanabe, M. Shibata, N. Sato, T. Kameyama, N. Akino, M. Munakata, M. Honada, M. Yoshizawa, N. Sugita

SCRIPTA MEDICA (BRNO)　81　(4)　249-260　2008/12
Non-contact Observation of Cultured Cells by Acoustic Impedance Microscope Peer-reviewed

A. Nakano, T. Uemura, N. Hozumi, M. Nagao, S. Yoshida, K. Kobayashi, S. Yamamoto, Y. Saijo

Proc. 2008 IEEE International Ultrasonics Symposium,　1893-1896　2008/11
Publisher: IEEE
DOI： 10.1109/ULTSYM.2008.0466 　
Biomedical Application of Acoustic Microscopy Diagnosis, Assessing Echogenecity and Biomechanics Peer-reviewed

Y. Saijo, Y. Hagiwara, K. Kobayashi, N. Okada, A.Tanaka, N. Hozumi, M. Tanaka

Proc. 2008 IEEE International Ultrasonics Symposium　1983-1986　2008/11

DOI： 10.1109/ULTSYM.2008.0489 　

ISSN：1051-0117
細胞観察のための音響インピーダンス顕微鏡の較正

中野愛子, 高山靖章, 植村務, 穂積直裕, 吉田祥子, 小林和人, 山本清二, 西條芳文

電気関係学会東海支部連合大会講演論文集(CD-ROM)　2008　ROMBUNNO.O-326　2008/09/12
生体組織用音響インピーダンス顕微鏡における収差検討

植村努, 穂積直裕, 中野愛子, 高山靖章, 武本諒太, 小林和人, 吉田祥子, 山本清二, 西條芳文

電気関係学会東海支部連合大会講演論文集(CD-ROM)　2008　ROMBUNNO.O-459　2008/09/12
Numerical experiment for Ultrasonic-Measurement-Integrated simulation of three-dimensional unsteady blood flow Peer-reviewed

Kenichi Funamoto, Toshiyuki Hayase, Yoshifumi Saijo, Tomoyuki Yambe

ANNALS OF BIOMEDICAL ENGINEERING　36　(8)　1383-1397　2008/08
Publisher: SPRINGER
DOI： 10.1007/s10439-008-9519-7 　

ISSN：0090-6964

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

Hozumi Naohiro, Nakano Aiko, Terauchi Satoshi, Nagao Masayuki, Yoshida Sachiko, Kobayashi Kazuto, Yamamoto Seiji, Saijo Yoshifumi

MODERN PHYSICS LETTERS B　22　(11)　1129-1134　2008/05/10

DOI： 10.1142/S0217984908015954 　

ISSN：0217-9849
【食道疾患の臨床 update】食道癌食道癌ステント治療の未来 Invited Peer-reviewed

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

臨床消化器内科　23　(7)　1056-1059　2008/05
音響インピーダンス顕微鏡による培養細胞の定量評価

中野愛子, 穂積直裕, 寺内智, 長尾雅行, 吉田祥子, 小林和人, 山本清二, 西條芳文

電気学会全国大会講演論文集　2008　(1)　155　2008/03/19
開口合成による3次元超音波顕微鏡の基礎検討

糟谷智美, 穂積直裕, 寺内智, 長尾雅行, 吉田祥子, 小林和人, 山本清二, 西條芳文

電気学会全国大会講演論文集　2008　(1)　157　2008/03/19
生体組織用音響インピーダンス顕微鏡の較正―食塩水による精度評価―

浜川佑也, 穂積直裕, 寺内智, 長尾雅行, 吉田祥子, 小林和人, 山本清二, 西條芳文

電気学会全国大会講演論文集　2008　(1)　156　2008/03/19
生体組織用音響インピーダンス顕微鏡の較正―集束角の影響解析と小脳組織観察―

寺内智, 村上義信, 長尾雅行, 吉田祥子, 小林和人, 西條芳文, 穂積直裕

電気学会全国大会講演論文集　2008　(1)　154　2008/03/19
Radio Frequency Signal Analysis for Tissue Characterization of Artificial Skin Peer-reviewed

Takahiro Iwamoto, Yoshifumi Saijo, Naohiro Hozumi, Kazuto Kobayashi, Nagaya Okada, Akira Tanaka, Makoto Yoshizawa

11th international symposium on advanced biomedical ultrasounｄ　2008/03
Numerical Evaluation of Ultrasonic-Measurement-Integrated Simulation of Blood Flow

Kenichi Funamoto, Toshiyuki Hayase, Yoshifumi Saijo, Tomoyuki Yambe

Proceedings of 5th International Bio-Fluid Symposium and Workshop　116-117　2008/03
Fractal dimension of 40 MHz intravascular ultrasound radio frequency signals Peer-reviewed

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

ULTRASONICS　48　(1)　35-39　2008/03
Publisher: ELSEVIER SCIENCE BV
DOI： 10.1016/j.ultras.2007.08.006 　

ISSN：0041-624X

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

Yasuyuki Shiraishi, T. Yambe, Y. Saijo, S. Masuda, G. Takahashi, K. Tabayashi, T. Fujimoto, M. Umezu

IFMBE Proceedings　22　2564-2567　2008

DOI： 10.1007/978-3-540-89208-3_615 　

ISSN：1680-0737

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Endoventricular patch plasty, called the Dor procedure, is performed as a heart reconstruction for the surgical treatment of the patients with severe heart failure associated with anteroapical large myocardial infarction. The authors have been establishing a new engineering method for the individual simulation of operational procedure in order to determine the optimal left ventricular size and shape and to estimate the volumetric reduction after the surgical ventricular restoration in each patient. In this study, three individual ventricular shapes were fabricated by numerically resampled data which were obtained from the diagnostic magnetic resonance imaging in each subject. Prior to the fabrication of the models, epi- or endocardial envelope curve was outlined without papillary muscles or tendinous cords in each end-diastolic and end-systolic phase for the compatible reference in echocardiogram, computed tomography or magnetic resonance imaging investigations. And the mechanical silicone rubber models were made by the use of female moulding for the discussion of each subject among surgeons. In this paper, we examined a methodology for the simulation of ventriculoplasty by using a silicone rubber model and evaluated the capability of quantitative expression of ejection fraction. © 2009 Springer Berlin Heidelberg.
ELASTIC CHANGES OF CAPSULE IN A RAT KNEE CONTRACTURE MODEL ASSESSED BY SCANNING ACOUSTIC MICROSCOPY Peer-reviewed

Y. Hagiwara, E. Chimoto, A. Ando, Y. Saijo, E. Itoi

ACOUSTICAL IMAGING, VOL 29　29　187-+　2008
Publisher: SPRINGER
ISSN：0270-5117

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Sound speed of a capsule in a rat knee contracture model was measured by scanning acoustic microscopy. There was no statistical significant difference in the anterior capsule compared with the control group. However, the sound speed of the posterior capsule was significantly greater compared with the control group after prolonged immobilization.
ULTRASONIC NANO-IMAGING SYSTEM FOR MEDICINE AND BIOLOGY Peer-reviewed

Y. Saijo, N. Hozumi, K. Kobayashi, N. Okada, Y. Hagiwara, H. Sasaki, E. D. S. Filho, T. Yambe

ACOUSTICAL IMAGING, VOL 29　29　181-+　2008
Publisher: SPRINGER
ISSN：0270-5117

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The ultrasonic nano-imaging system for medicine and biology that has two measurement modes was developed. The transmission mode realized non-contact high resolution imaging of cultured cells. This mode can be applied for assessment of biomechanics of the cells and thinly sliced tissues. The reflection mode visualized fine structures of the brain of rat. This mode can be applied for intra-operative pathological examination because it does not require slicing or staining.
3次元超音波顕微鏡の開発による再生皮膚組織モデルの自動診断

西條芳文, 萩原嘉廣, 岩本貴宏, 小林和人, 岡田長也, 田中明, 穂積直裕, 富畑賢治

日本生体医工学会大会プログラム・論文集(CD-ROM)　47th　ROMBUNNO.FC-24-4　2008
烏口肩峰靭帯の変性と弾性との関係－超音波顕微鏡を用いた計測. Peer-reviewed

木島泰明, 皆川洋至, 山本宣幸, 冨岡立, 阿部秀一, 菊池一馬, 島田洋一, 西條芳文, 佐野博高, 井樋栄二

肩関節　32　233-235　2008

DOI： 10.11296/katakansetsu.32.233 　
腱板断裂における烏口肩峰靭帯の弾性. Peer-reviewed

木島泰明, 皆川洋至, 山本宣幸, 冨岡立, 阿部秀一, 菊池一馬, 島田洋一, 西條芳文, 佐野博高, 井樋栄二

肩関節　32　353-356　2008

DOI： 10.11296/katakansetsu.32.353 　
Three-dimensional ultrasound imaging of regenerated skin with high frequency ultrasound. Peer-reviewed

Yoshifumi Saijo, Yoshihiro Hagiwara, Kazuto Kobayashi, Nagaya Okada, Akira Tanaka, Naohiro Hozumi, Takahiro Iwamoto

Proceedings of the 2008 IEEE International Symposium on Biomedical Imaging: From Nano to Macro, Paris, France, May 14-17, 2008　1231-1234　2008
Publisher: IEEE
DOI： 10.1109/ISBI.2008.4541225 　
Sensorless Control for a Sophisticated Artificial Myocardial Contraction by using Shape Memory Alloy Fibre Peer-reviewed

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

2008 30TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY, VOLS 1-8　711-+　2008
Publisher: IEEE
ISSN：1557-170X

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The authors have been developing an artificial myocardium, which is capable of supporting natural contractile function from the outside of the ventricle. The system was originally designed by using sophisticated covalent shape memory alloy fibres, and the surface did not implicate blood compatibility. The purpose of our study on the development of artificial myocardium was to achieve the assistance of myocardial functional reproduction by the integrative small mechanical elements without sensors, so that the effective circulatory support could be accomplished. In this study, the authors fabricated the prototype artificial myocardial assist unit composed of the sophisticated shape memory alloy fibre (Biometal), the diameter of which was 100 microns, and examined the mechanical response by using pulse width modulation (PWM) control method in each unit. Prior to the evaluation of dynamic characteristics, the relationship between strain and electric resistance and also the inditial response of each unit were obtained. The component for the PWM control was designed in order to regulate the myocardial contractile function, which consisted of an originally-designed RISC microcomputer with the input of displacement, and its output signal was controlled by pulse wave modulation method. As a result, the optimal PWM parameters were confirmed and the fibrous displacement was successfully regulated under the different heat transfer conditions simulating internal body temperature as well as bias tensile loading. Then it was indicated that this control theory might be applied for more sophisticated ventricular passive or active restraint by the artificial myocardium on physiological demand.
High frequency ultrasound imaging of surface and subsurface structures of fingerprints. International-journal Peer-reviewed

Yoshifumi Saijo, Kazuto Kobayashi, Nagaya Okada, Naohiro Hozumi, Yoshihiro Hagiwara, Akira Tanaka, Takahiro Iwamoto

Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference　2008　2173-6　2008

DOI： 10.1109/IEMBS.2008.4649625 　

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High frequency ultrasound is suitable for non-invasive evaluation of skin because it can obtain both morphological and biomechanical information. A specially developed acoustic microscope system with the central frequency of 100 MHz was developed. The system was capable of (1) conventional C-mode acoustic microscope imaging of thinly sliced tissue, (2) ultrasound impedance imaging of the surface of in vivo thick tissue and (3) 3D ultrasound imaging of inside of the in vivo tissue. In the present study, ultrasound impedance imaging and 3D ultrasound imaging of in vivo fingerprints were obtained. The impedance image showed pores of the sweat glands in the surface of fingerprint and 3D ultrasound imaging showed glands of the rear surface of fingerprint. Both findings were not visualized by normal optical imaging, thus the system can be applied to pathological diagnosis of skin lesions and assessment of aging of the skin in cosmetic point of view.
High frequency ultrasound characterization of artificial skin. International-journal Peer-reviewed

Takahiro Iwamoto, Yoshifumi Saijo, Naohiro Hozumi, Kazuto Kobayashi, Nagaya Okada, Akira Tanaka, Makoto Yoshizawa

Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference　2008　2185-8　2008

DOI： 10.1109/IEMBS.2008.4649628 　

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Regenerated skin with 3-dimensional structure is desired for the treatment of large burn and for the plastic surgery. High frequency ultrasound is suitable for non-destructive testing of the skin model because it provides information on morphology and mechanical properties. In this paper, spectral parameters of ultrasound radio-frequency signal from a specially developed high-frequency ultrasound imaging system were evaluated for tissue characterization of artificial skin. Results suggest that spectral parameters are useful for classification of epidermis and dermis in the artificial skin model. The system is also a useful tool for the noninvasive and nondestructive evaluation of skin.
Elasticity of the supraspinatus tendon-muscle unit is preserved after acute tendon tearing in the rabbit Peer-reviewed

Mitsuyoshi Mineta, Hirotaka Sano, Ryogo Ichinose, Yoshifumi Saijo, Eiji Itoi

Tohoku Journal of Experimental Medicine　216　(1)　17-24　2008

DOI： 10.1620/tjem.216.17 　

ISSN：0040-8727 1349-3329

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Supraspinatus tendon tearing is one of the most common causes of the shoulder pain and dysfunction, which often requires a surgical repair. In this situation, proximal tendon stump is usually retracted medially from its original insertion. For successful reduction of the retracted tendon stump to its original insertion, the elasticity of the tendon-muscle unit should be preserved by the time of surgery. The purpose of the present study was to clarify the chronological changes in the elasticity of the supraspinatus tendon-muscle unit after acute tendon tearing to determine the optimal timing for the surgery. Right supraspinatus tendon was detached (detached side) in 40 male Japanese white rabbits, with left shoulders served as controls (control side). Eight animals were euthanized at 3 days and 1, 2, 4, or 8 weeks after surgery. Tissue sound speed that closely correlates to its elasticity was measured with a scanning acoustic microscope. In the supraspinatus tendon, tissue sound speed at 3 days after surgery was 1691.1 m/s, compared to 1714.3 m/s at the control side, but the difference was not statistically significant at any postoperative time period up to 8 weeks. In the supraspinatus muscle, tissue sound speed was not affected at all by the detachment of the tendon. The present study indicated that the elasticity of the supraspinatus tendon-muscle unit was well preserved for 8 weeks after the detachment. In the clinical practice, the retracted supraspinatus tendon stump could be repaired without excessive tension by 8 weeks from the acute tendon tearing. © 2008 Tohoku University Medical Press.
Detection and quantification of calcifications in intravascular ultrasound images by automatic thresholding Peer-reviewed

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

ULTRASOUND IN MEDICINE AND BIOLOGY　34　(1)　160-165　2008/01
Publisher: ELSEVIER SCIENCE INC
DOI： 10.1016/j.ultrasmedbio.2007.06.025 　

ISSN：0301-5629

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An innovative application of automatic thresholding is used for the detection of calcification regions in intravascular ultrasound images. A priori knowledge of the acoustic shadow that usually accompanies calcification regions is used to discriminate these from other bright regions in the image. A method for the calculation of the angle of calcification has also been developed. The proposed algorithms are applied to in-vivo images obtained from left anterior descending coronary arteries during percutaneous transluminal coronary angioplasty (n = 14). The resulting specificity is 72% and the sensitivity 84%. The receiver operating characteristic curve, the area under the curve being equal to 0.91, is plotted to evaluate the algorithm performance.
Radio Frequency Signal Analysis of Intravascular Ultrasound Aiming to Tissue Characterization of Coronary Artery by using Self Organization Map Peer-reviewed

Takahiro Iwamoto, Yoshifumi Saijo, Akira Tanaka, Esmerald dos, Santos Filho, Shuo Li, Makoto Yoshizawa

3rd Tohoku-NUS Joint Symposium on Nano-Biomedical Engineering in the East Asian-Pacific Rim Region　2007/12
Effect of Time Resolution of Measurement on Ultrasonic-Measurement-Integrated Simulation of Three-Dimensional Unsteady Blood Flow in an Aneurysmal Aorta

Kenichi Funamoto, Toshiyuki Hayase, Yoshifumi Saijo, Tomoyuki Yambe

Proceedings of the 3rd Tohoku-NUS Joint Symposium on Nano-Biomedical Engineering in the East Asian-Pacific Rim Region　13-16　2007/12
医工学による右心流出路再建の評価方法

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

人工臓器　36　(2)　S109-S109　2007/10
Macrophage colony-stimulating factor improves cardiac function after ischemic injury by inducing vascular endothelial growth factor production and survival of cardiomyocytes Peer-reviewed

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

AMERICAN JOURNAL OF PATHOLOGY　171　(4)　1093-1103　2007/10
Publisher: AMER SOC INVESTIGATIVE PATHOLOGY, INC
DOI： 10.2353/ajpath.2007.061191 　

ISSN：0002-9440

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

中野愛子, 穂積直裕, 寺内智, 長尾雅行, 吉田祥子, 小林和人, 山本清二, 西條芳文

電気関係学会東海支部連合大会講演論文集(CD-ROM)　2007　ROMBUNNO.O-288　2007/09/14
生体組織用音響インピーダンス顕微鏡の精度評価―集束角の影響解析―

寺内智, 村上義信, 長尾雅行, 吉田祥子, 小林和人, 西條芳文, 穂積直裕

電気関係学会東海支部連合大会講演論文集(CD-ROM)　2007　ROMBUNNO.O-287　2007/09/14
超音波音速‐インピーダンス顕微鏡によるin vivoマイクロイメージングシステム

小林和人, 西條芳文, 穂積直裕

日本音響学会研究発表会講演論文集(CD-ROM)　2007　1-9-13　2007/09/12

ISSN：1880-7658
Measurement of soft tissue elasticity in the congenital clubfoot using scanning acoustic microscope Peer-reviewed

Koshi Hattori, Hirotaka Sano, Yoshifumi Saijo, Atsushi Kita, Masahito Hatori, Shoichi Kokubun, Eiji Itoi

JOURNAL OF PEDIATRIC ORTHOPAEDICS-PART B　16　(5)　357-362　2007/09
Publisher: LIPPINCOTT WILLIAMS & WILKINS
DOI： 10.1097/BPB.0b013e328248b4d0 　

ISSN：1060-152X

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To compare the soft-tissue elasticity between the medial, lateral, and posterior aspects, the deltoid and calcaneofibular ligaments, and the medial, lateral, and posterior capsular tissues were collected from 27 feet of 16 congenital-clubfoot patients. The tissue sound speed, which closely correlates to the Young's modulus, was measured using a scanning acoustic microscope. Contrary to our expectations, lateral ligament showed a significantly higher sound speed than medial ligament (P=0.0023). Lateral capsule also showed a higher sound speed than the medial one (P=0.0338). The results of the study indicated that the lateral soft tissues including the ligaments and capsule underwent severe contracture in congenital clubfoot.
オプティカルフロー法による心血管内血流の可視化

西條芳文, 田中明, 田林晄一, 山家智之

Journal of Cardiology　50　(Suppl.I)　379-379　2007/08
Ultrasonic tissue characterization of atherosclerosis by a speed-of-sound microscanning system Peer-reviewed

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

IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL　54　(8)　1571-1577　2007/08
Publisher: IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
DOI： 10.1109/TUFFC.2007.427 　

ISSN：0885-3010

eISSN：1525-8955

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

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

エレクトロニクスの臨床　(76)　23-34　2007/07
Accuracy of Ultrasonic-Measurement-Integrated Simulation for Three-Dimensional Blood Flow in Aneurysmal Aorta Peer-reviewed

Kenichi Funamoto, Toshiyuki Hayase, Yoshifumi Saijo, Tomoyuki Yambe

Proceedings of the 5th Joint ASME/JSME Fluids Engineering Conference　CD-ROM　2007/07

DOI： 10.1115/FEDSM2007-37497 　
動脈の血圧反射機能感受性診断装置の発明 Invited

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

東北医学雑誌　119　(1)　73-77　2007/06
形状記憶合金を用いた人工的蠕動運動型人工食道

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

北海道外科雑誌　52　(1)　85-85　2007/06
Self-organizing map classification of coronary plaque on radio-frequency signal of intravascular ultrasound Peer-reviewed

Takahiro Iwamoto, Yoshifumi Saijo, Akira Tanaka, Esmerald dos, Santos Filho, Shuo Li, Makoto Yoshizawa

Paris-Sendai Symposium on Ultrasonic Tissue Characterization and Small Animal Imaging　2007/04
Coronary plaque classification with intravascular ultrasound radio-frequency signal analysis using self-organizing map Peer-reviewed

Takahiro Iwamoto, Yoshifumi Saijo, Akira Tanaka, Esmerald dos, Santos Filho, Shuo Li, Makoto Yoshizawa

ICU 2007　2007/04
Radio frequency signal analysis for tissue characterization of coronary artery: in vitro intravascular ultrasound study Peer-reviewed

Takahiro Iwamoto, Yoshifumi Saijo, Akira Tanaka, Esmerald dos, Santos Filho, Shuo Li, Makoto Yoshizawa

29th International Symposium on Acoustical Imaging (AI29)　2007/04
生体用音響インピーダンス顕微鏡における観察用基板表面処理の影響

木村あゆみ, 寺内智, 正木志保, 村上義信, 長尾雅行, 吉田祥子, 小林和人, 西條芳文, 穂積直裕

電気学会全国大会講演論文集　2007　(1)　169　2007/03/15
生体組織用音響インピーダンス顕微鏡の校正法の検討

寺内智, 木村あゆみ, 村上義信, 長尾雅行, 吉田祥子, 小林和人, 西條芳文, 穂積直裕

電気学会全国大会講演論文集　2007　(1)　170　2007/03/15
Evaluation of Cardiac Function of the Patients with Left Ventricular Assist Device by Transesophageal Echocardiography Peer-reviewed

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

WORLD CONGRESS ON MEDICAL PHYSICS AND BIOMEDICAL ENGINEERING 2006, VOL 14, PTS 1-6　14　4146-+　2007
Publisher: SPRINGER-VERLAG BERLIN
ISSN：1680-0737

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

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

Journal of Life Support Technology　19　192-192　2007
Publisher: The Society of Life Support Engineering
DOI： 10.5136/lifesupport.19.Supplement_192 　

ISSN：1341-9455
Support mechanism of a newly-designed mechanical artificial myocardium using shape memory alloy fibres

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

IFMBE Proceedings　14　(1)　3161-3164　2007

DOI： 10.1007/978-3-540-36841-0_799 　

ISSN：1680-0737

eISSN：1433-9277

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

Akira Tanaka, Yoshifumi Saijo

Annual International Conference of the IEEE Engineering in Medicine and Biology - Proceedings　4500-4503　2007

DOI： 10.1109/IEMBS.2007.4353339 　

ISSN：0589-1019

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Left atrial spontaneous echo contrast (SEC) is a dynamic smoke-like signal caused by an increased ultrasonic backscatter from aggregation of the cellular components of blood in the conditions of blood stases or low-velocity blood flow. SEC can be detected by transesophageal echocardiography (TEE). SEC has been proposed as an important cadioembolic source in patients with nonrheumatic arial fibrillation. Previous clinical investigations have shown that the presence of SEC is associated with a greater incidence of left atrial thrombi. Usually, the blood flow velocity is slower than lower limit of Doppler method in SEC. In order to diagnose SEC quantitatively, blood flow visualization in left atrium was performed using gradient based optical flow estimation. A movie of left atrium (LA) with SEC in a patient with atrial fibrillation was recorded by TEE with the frequency range of 4-7.5 MHz. Serial still frames were made from the movie. The 2-D flow vector map was calculated from consecutive frame images using gradient based optical flow estimation. In the result of 2-D blood flow vector map, the low and swirling flow in LA were successfully visualized. © 2007 IEEE.
Ultrasound speed and impedance microscopy for in vivo imaging Peer-reviewed

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

Annual International Conference of the IEEE Engineering in Medicine and Biology - Proceedings　1350-1353　2007

DOI： 10.1109/IEMBS.2007.4352548 　

ISSN：0589-1019

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Ultrasound speed and impedance microscopy was developed in order to develop in vivo imaging system. The sound speed mode realized non-contact high resolution imaging of cultured cells. This mode can be applied for assessment of biomechanics of the cells and thinly sliced tissues. The impedance mode visualized fine structures of the surface of the rat's brain. This mode can be applied for intra-operative pathological examination because it does not require slicing or staining. © 2007 IEEE.
Morphological approach for the functional improvement of an artificial myocardial assist device using shape memory alloy fibres Peer-reviewed

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

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

DOI： 10.1109/IEMBS.2007.4353204 　

ISSN：0589-1019

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

N. Hozumi, A. Nakano, S. Terauchi, M. Nagao, S. Yoshida, K. Kobayashi, S. Yamamoto, Y. Saijo

2007 IEEE ULTRASONICS SYMPOSIUM PROCEEDINGS, VOLS 1-6　801-+　2007
Publisher: IEEE
DOI： 10.1109/ULTSYM.2007.205 　

ISSN：1051-0117

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This report deals with the scanning acoustic microscope for imaging cross sectional acoustic impedance of biological soft tissues. A focused acoustic beam with a wide frequency range up to about 100 MHz was transmitted to the tissue object in contact with the "rear surface" of plastic substrate. The reflected signals from the target and reference are interpreted into local acoustic impedance. Two-dimensional profile is obtained by scanning the transducer. As the incidence is not vertical, not only longitudinal wave but also transversal wave is generated in the substrate. The error in estimated acoustic impedance assuming vertical incidence was discussed. The error is not negligible if the angle of focusing is large, or the acoustic impedance of the reference material is far different from the target. However it can be compensated, if the beam pattern and acoustic parameters of coupling medium and substrate were known. The improvement of precision brought by the compensation was ensured by using a droplet of saline solution of which acoustic Impedance was known. Finally, a cerebellum tissue of rat was observed with a good precision.
B-mode and C-mode imaging of regenerated 3D skin model with 100 MHz ultrasound Peer-reviewed

Yoshifumi Saijo, Yoshihiro Hagiwara, Kazuto Kobayashi, Nagaya Okada, Akira Tanaka, Naohiro Hozumi, Kenji Tomihata

2007 IEEE ULTRASONICS SYMPOSIUM PROCEEDINGS, VOLS 1-6　244-+　2007
Publisher: IEEE
DOI： 10.1109/ULTSYM.2007.72 　

ISSN：1051-0117

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Regenerated skin with 3D structure is desired for the treatment of large burn and for the plastic surgery. High frequency ultrasound is suitable for non-destructive testing of the skin model because it provides information on morphology and mechanical properties. An acoustic microscope system capable of imaging B-mode and C-mode was developed for analysis of 3D skin model. C-mode imaging provided quantitative values of attenuation and sound speed. B-mode imaging showed fine structure of the model. Sound speed in C-mode and intensity in B-mode imaging showed higher values at the area of dense fibroblasts. The system can be used as the nondestructive evaluation tool in the process of producing 3D skin model and as the in vivo imaging system after transplantation.
生体内超音波ナノ・イメージング法の開発

西條芳文, 穂積直裕, 小林和人, DOS SANTOS FILHO Esmeraldo

日本生体医工学会大会プログラム・論文集(CD-ROM)　46th　ROMBUNNO.PS2-9-2　2007
Numerical Realization of Blood Flow in Aneurysmal Aorta by Integrating Measurement and Simulation

Toshiyuki Hayase, Kenichi Funamoto, Takayuki Yamagata, Lei Liu, Atsushi Shirai, Makoto Ohta, Kosuke Inoue, Yoshifumi Saijo, Tomoyuki Yambe

Future Medical Engineering Based on Bionanotechnology　857-868　2007
Biochemical evaluation of an artificial anal sphincter made from shape memory alloys Peer-reviewed

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

JOURNAL OF ARTIFICIAL ORGANS　10　(4)　223-227　2007
Publisher: SPRINGER TOKYO
DOI： 10.1007/s10047-007-0395-y 　

ISSN：1434-7229

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

Akira Tanaka, Yoshifumi Saijo

2007 ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY, VOLS 1-16　1　4500-+　2007
Publisher: IEEE
DOI： 10.1109/IEMBS.2007.4353339 　

ISSN：1094-687X

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Left atrial spontaneous echo contrast (SEC) is a dynamic smoke-like signal caused by an increased ultrasonic backscatter from aggregation of the cellular components of blood in the conditions of blood stases or low-velocity blood flow. SEC can be detected by transesophageal echocardiography (TEE). SEC has been proposed as an important cadioembolic source in patients with nonrheumatic arial fibrillation. Previous clinical investigations have shown that the presence of SEC is associated with a greater incidence of left atrial thrombi. Usually, the blood flow velocity is slower than lower limit of Doppler method in SEC. In order to diagnose SEC quantitatively, blood flow visualization in left atrium was performed using gradient based optical flow estimation. A movie of left atrium (LA) with SEC in a patient with atrial fibrillation was recorded by TEE with the frequency range of 4-7.5 MHz. Serial still frames were made from the movie. The 2-D flow vector map was calculated from consecutive frame images using gradient based optical flow estimation. In the result of 2-D blood flow vector map, the low and swirling flow in LA were successfully visualized.
Morphological approach for the functional improvement of an artificial myocardial assist device using shape memory alloy fibres Peer-reviewed

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

2007 ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY, VOLS 1-16　1　3974-3977　2007
Publisher: IEEE
DOI： 10.1109/IEMBS.2007.4353204 　

ISSN：1094-687X

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

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

2007 ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY, VOLS 1-16　1　1350-+　2007
Publisher: IEEE
DOI： 10.1109/IEMBS.2007.4352548 　

ISSN：1094-687X

More details Close

Ultrasound speed and impedance microscopy was developed in order to develop in vivo imaging system. The sound speed mode realized non-contact high resolution imaging of cultured cells. This mode can be applied for assessment of biomechanics of the cells and thinly sliced tissues. The impedance mode visualized fine structures of the surface of. the rat's brain. This mode can be applied for intra-operative pathological examination because it does not require slicing or staining.
Intravascular two-dimensional tissue strain imaging Peer-reviewed

Yoshifumi Saijo, Akira Tanaka, Takahiro Iwamoto, Esmeraldo dos Santos Filho, Makoto Yoshizawa, Akira Hirosaka, Mikihiro Kijima, Yoshihisa Akino, Yasushi Hanadate, Tomoyuki Yambe

ULTRASONICS　44　E147-E151　2006/12
Publisher: ELSEVIER SCIENCE BV
DOI： 10.1016/j.ultras.2006.06.049 　

ISSN：0041-624X

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Our goal is to achieve the precise quantitative imaging of tissue elasticity in clinical settings. In the present study, we measured basic ultrasonic characteristics of atherosclerosis by two-dimensional (2D) intravascular tissue velocity imaging. Radio-frequency (RF) signal from a clinically used IVUS apparatus was digitized at 500 MSa/s and stored in a workstation. First, the correlation coefficient between two consecutive frames was calculated in the rotational direction and the rotational disuniformity was corrected to obtain the maximum correlation coefficient. Then, the polar coordinate images were converted into rectangular coordinate images and the images were divided into 64 by 64 square shaped regions of interest (ROIs). The correlation and displacement of the ROIs between the consecutive two frames were calculated by template matching method. Two-dimensional tissue velocity was defined as the vectors of displacement of ROI with 0.7 and more correlation. IVUS studies were performed in directional coronary atherectomy (DCA) procedures. The specimens excised by DCA were stained with Elastica-Masson's trichrome staining and CD68 immunochemical staining. Eleven cases ( including two no re-flow cases and one perforation case) were intraoperatively observed by IVUS and the specimens obtained by DCA were observed by optical microscopy. The specimen from homogeneous 2D strain was collagen dominant fibrosis and the specimen from a lesion with complex vectors contained CD68 positive cells and degenerated collagen fibers, which indicated the plaque was vulnerable. (c) 2006 Elsevier B. V. All rights reserved.
Ultrasonic speed microscopy for imaging of coronary artery Peer-reviewed

Yoshifumi Saijo, Naohiro Hozumi, Cheolkyou Lee, Masayuki Nagao, Kazuto Kobayashi, Nagaya Oakada, Naohiko Tanaka, Esmeraldo Dos Santos Filho, Hidehiko Sasaki, Motonao Tanaka, Tomoyuki Yambe

ULTRASONICS　44　E51-E55　2006/12
Publisher: ELSEVIER SCIENCE BV
DOI： 10.1016/j.ultras.2006.06.050 　

ISSN：0041-624X

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We have been developing a scanning acoustic microscope ( SAM) system for medicine and biology featuring quantitative measurement of ultrasonic speed and attenuation of soft tissues. In the present study, we will propose a new concept ultrasonic speed microscopy that can measure the thickness and ultrasonic speed using fast Fourier transform of a single pulsed wave instead of continuous waves used in conventional SAM systems. Six coronary arteries were frozen and sectioned approximately 10 mu m in thickness. They were mounted on glass slides without cover slips. The scanning time of a frame with 300 X 300 pixels was 121 s and two- dimensional distribution of ultrasonic speed was obtained. The ultrasonic speed was 1720 m/ s in the thickened intima with collagen fiber, 1520 m/ s in lipid deposition underlying fibrous cap and 1830 m/ s in calcified lesion in the intima. These basic measurements will help understanding echogenecity in intravascular ultrasound ( IVUS) images. Imaging of coronary artery with the ultrasonic speed microscopy provides important information for study of IVUS coronary imaging. (c) 2006 Elsevier B. V. All rights reserved.
Multiple parametric IVUS imagings for detection of vulnerable plaque. Peer-reviewed

Saijo Y, Tanaka A, Santos Filho ED, Iwamoto T, Li S, Yoshizawa M, Yambe T

Proc 9th Sendai Symposium on Ultrasonic Tissue Characterization　1　13-17　2006/11/27
Classification of flow-limiting thrombus in acute coronary syndrome by acoustic microscopy Peer-reviewed

Sasaki H, Saijo Y, Kanno T, Tanaka M

Proc 9th Sendai Symposium on Ultrasonic Tissue Characterization　1　29-31　2006/11/27
Tissue sound speed of anterior cruciate ligament in estrogen-controlled rabbits. - A measurement using the scanning acoustic microscope - Peer-reviewed

Sano H, Hattori K, Komatsuda T, Saijo Y, Sugita T, Itoi E

Proc 9th Sendai Symposium on Ultrasonic Tissue Characterization　1　32-35　2006/11/27
Calibration for biological acoustic impedance microscope

Naohiro Hozumi, Satoshi Terauchi, Ayumi Kimura, Masayuki Nagao, Sachiko Yoshida, Kazuto Kobayashi, Yoshifumi Saijo

The Journal of the Acoustical Society of America　120　(5)　3111-3111　2006/11
Publisher: Acoustical Society of America (ASA)
DOI： 10.1121/1.4787598 　

ISSN：0001-4966
Imaging Myocardial Heterogeneity Using Propagation of Pulsive Vibration for Patients with Old myocardial Infarction

Hiroshi Kanai, Sachiko Watanabe, Yoshifumi Saijo, Motonao Tanaka

Abstract From the American Heart Association's Scientific Session 2006　664-665　2006/11

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November 12-15, 2006, Chicago, USA)
Non-mineralized fibrocartilage shows the lowest elastic modulus in the rabbit supraspinatus tendon insertion: Measurement with scanning acoustic microscopy Peer-reviewed

Hirotaka Sano, Yoshifumi Saijo, Shoichi Kokubun

JOURNAL OF SHOULDER AND ELBOW SURGERY　15　(6)　743-749　2006/11
Publisher: MOSBY-ELSEVIER
DOI： 10.1016/j.jse.2005.12.008 　

ISSN：1058-2746

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The acoustic properties of rabbit supraspinatus tendon insertions were measured by scanning acoustic microscopy. After cutting parallel to the supraspinatus tendon fibers, specimens were fixed with 10% neutralized formalin, embedded in paraffin, and sectioned. Both the sound speed and the attenuation constant were measured at the insertion site. The 2-dimensional distribution of the sound speed and that of the attenuation constant were displayed with color-coded scales. The acoustic properties reflected both the histologic architecture and the collagen type. In the tendon proper and the non-mineralized fibrocartilage, the sound speed and attenuation constant gradually decreased as the predominant collagen type changed from I to II. In the mineralized fibrocartilage, they increased markedly with the mineralization of the fibrocartilaginous tissue. These results indicate that the non-mineralized fibrocartilage shows the lowest elastic modulus among 4 zones at the insertion site, which could be interpreted as an adaptation to various types of biomechanical stress.
Mechanical Myocardial Assistance by the Shape Memory Alloy Fibre

SHIRAISHI Yasuyuki, YAMBE Tomoyuki, SEKINE Kazumitsu, SAIJO Yoshifumi, KONNO Satoshi, NITTA Shin-ichi, UMEZU Mitsuo, HOMMA Dai, OKAMOTO Eiji

電気学会研究会資料. LD, リニアドライブ研究会　2006　(48)　65-68　2006/10/26
微細機能繊維を応用した機械式人工心筋の開発心室補助効果と血管負荷整合 Peer-reviewed

白石泰之, 山家智之, 西條芳文, 関根一光, 小川大祐, 佐藤文博, 角張泰之, 伊藤慎二, 坂田亮, 和田由美子, 田中隆, 梅津光生, 田林晄一, 比嘉昌, 田中明, 吉澤誠, 藤本哲男, 増本憲泰, 仁田新一

人工臓器　35　(2)　S98-S98　2006/10

ISSN：0300-0818
形状記憶合金を使用した蠕動運動アクチュエータの人工臓器としての可能性 Peer-reviewed

関根一光, 白石泰之, 山家智之, 西條芳文, 堀義生, 松木英敏, 佐藤文博, 角張泰之, 三浦英和, 前田剛, 仁田新一

人工臓器　35　(2)　S76-S76　2006/10

ISSN：0300-0818
形状記憶合金を応用した人工心筋要素の機械特性と駆動制御に関する基礎検討

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

人工臓器　35　(2)　S167-S167　2006/10
長期埋込型形状記憶合金人工括約筋の生体適合性評価

劉紅箭, 羅雲, 比嘉昌, 西條芳文, 白石泰之, 関根一光, 山家智之

人工臓器　35　(2)　S166-S166　2006/10
東北大学における無拍動流左心補助人工心臓EVAHEARTの長期動物実験による評価

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

人工臓器　35　(2)　S156-S156　2006/10
再生医療の評価方法としての高周波数超音波の可能性

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

人工臓器　35　(2)　S121-S121　2006/10
音響インピーダンス顕微鏡によるラットの小脳皮質発達評価

木村あゆみ, 寺内智, 村上義信, 長尾雅行, 吉田祥子, 穂積直裕, 小林和人, 西条芳文

電気関係学会東海支部連合大会講演論文集(CD-ROM)　2006　O-074　2006/09/15
IVUSにおけるAttenuation Imagingの開発

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

Journal of Cardiology　48　(Suppl.I)　352-352　2006/09
Numerical Study on Variation of Feedback Methods in Ultrasonic-Measurement-Integrated Simulation of Blood Flow in the Aneurysmal Aorta Peer-reviewed

Kenichi Funamoto, Toshiyuki Hayase, Yoshifumi Saijo, Tomoyuki Yambe

JSME International Journal, Series C　49　(1)　144-155　2006/09
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmec.49.144 　

ISSN：1344-7653

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The complicated relationships between hemodynamics and aneurysms have been investigated intensively. However, existing methodologies have inherent limitations in providing real blood flow fields. The authors have proposed Ultrasonic-Measurement-Integrated (UMI) simulation, in which the feedback signals lead to convergence of the calculated blood flow structure to the real one even with incorrect boundary/initial conditions. In UMI simulation, determination of the feedback law is substantially important, but detailed particulars remain to be accounted for. In this paper, first, the effects of density of feedback points and feedback domains are systematically investigated. Improvement of computational accuracy in the feedback domain is achieved even in low density of feedback points of 25%, and such improvement persists in the downstream region. Secondly, the most effective combination of feedback gains for momentum and pressure equations is investigated, confirming the validity of the simple condition to use the same value for the velocity and pressure gains.
Automated calcification detection and quantification in intravascular ultrasound images by adaptive threshoding Peer-reviewed

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

Proc. of the World Congress on Medical Physics and Biomedical engineering　2006/08
Improvement of Accuracy of Blood Flow Simulation by Integrating Measurement Using Ultrasonic Doppler Method

Kenichi Funamoto, Toshiyuki Hayase, Yoshifumi Saijo, Tomoyuki Yambe

Proceedings of the 5th World Congress of Biomechanics　CD-ROM　2006/07
Does decalcification alter the tissue sound speed of rabbit supraspinatus tendon insertion? In vitro measurement using scanning acoustic microscopy Peer-reviewed

Hirotaka Sano, Koshi Hattori, Yoshifumi Saijo, Shoichi Kokubun

ULTRASONICS　44　(3)　297-301　2006/07
Publisher: ELSEVIER SCIENCE BV
DOI： 10.1016/j.ultras.2006.03.002 　

ISSN：0041-624X

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Failure of the tendon or ligament insertions is one of the most common injuries in the Orthopaedic field. To elucidate the pathogenesis of those injuries, the authors had attempted to measure the tissue sound speed that. could be correlated to its elasticity using scanning acoustic microscopy (SAM). For the application of SAM to tendon or ligament insertions, it was necessary to determine the role of decalcification in SAM measurements since mineralized tissues including bone or mineralized fibrocartilage were present at the insertion site. To assess whether decalcification alters the tissue sound speed or not, supraspinatus tendon insertion of six Japanese white rabbits were measured with SAM operating in the frequency range of 50-150 MHz. Right supraspinatus tendons attached to the humeral head were cut into two pieces at the center of the tendon. Then, they were fixed with 10% neutralized formalin for 12 h. In each specimen, medial half was not decalcified, while lateral half was decalcified with ethylene-diamine-tetra-acetic acid (EDTA). After embedding in paraffin, 5 mu m thick specimens were prepared for the measurement using SAM. The mean sound speed in each histologic zone was evaluated, and subsequently compared to that measured in the undecalcified and the decalcified specimens. Mean sound speed of non-mineralized fibrocartilage was 1544 m/s in the undecalcified specimens, while the value of 1541 m/s was determined in the decalcified ones. On the other band, it decreased 2-3% after decalcification in the mineralized tissue including mineralized fibrocartilage and bone (mineralized fibrocartilage: undecalcified = 1648 m/s, decalcified = 1604 m/s; bone: undecalcified = 1716 m/s, decalcified = 1677 m/s). However, no significant differences were found between the undecalcified and the decalcified specimens (non-mineralized fibrocartilage: p = 0.84, mineralized fibrocartilage: p = 0.35, bone: p = 0.28). These results indicate that SAM could be applied to determine the properties of the tendon or the ligament insertions after decalcification with EDTA. Although SAM is applicable only for in vitro experimental study, it is expected that these data will contribute to better understanding concerning the biomechanics of tendon or ligament insertions as well as the pathogenesis of their failure at a microscopic level. (c) 2006 Elsevier B.V. All rights reserved.
Segmentation of calcification regions in intravascular ultrasound images by adaptive threshold Peer-reviewed

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

Proc. of 19th IEEE International Symposium on Computer-based Medical Systems　446-451　2006/06

DOI： 10.1109/CBMS.2006.142 　
人工心筋を応用した新しい機械式心臓モデル構築の試み Peer-reviewed

白石泰之, 伊藤慎二, 山家智之, 永利潤, 西條芳文, 関根一光, 金野敏, 朴栄光, 植松美幸, 増本憲泰, 田中隆, 藤本哲男, 梅津光生, 本間大

生体医工学　44　(2)　320-320　2006/06
蠕動運動機能を有する生体内埋め込み可能な人工食道の開発研究 Peer-reviewed

関根一光, 山家智之, 西條芳文, 白石泰之, 堀義生, 松木英敏, 佐藤文博

北海道外科雑誌　51　(1)　79-79　2006/06

ISSN：1347-443X
Fundamental Study of Transient Characteristics of Ultrasonic-Measurement-Integrated Simulation toward Reproduction of Unsteady Blood Flows

Kenichi Funamoto, Toshiyuki Hayase, Yoshifumi Saijo, Tomoyuki Yambe

Proceedings of ASME 2006 Summer Bioengineering Conference　CD-ROM　2006/06
IVUS beyond the horizon. Invited Peer-reviewed

van der Steen AFW, Baldewsing RA Degertekin FL Emelianov, S Frijlink ME, Furukawa Y Goertz, D Karaman, M Khuri-Yakub, PT Kim, K Mastik F, Moriya T Oralkan, O, Saijo Y, Schaar JA Serruys PW Sethuraman, S Tanaka, A Vos, HJ, Witte, R, O’Donnell M

Eurointerv　2　132-142　2006/06
科研費研究課題の成果 ●基盤研究（B）超音波による血管内皮細胞のナノ・イメージング Invited

SAIJO Yoshifumi, SATO Masaaki, HOZUMI Naohiro SUZUKI Satoshi, KOBAYASHI Kazuto

INNERVISION　21　(7)　48-48　2006/06
Publisher: None
ISSN：0913-8919
超音波によるナノ・イメージングの医療への応用

西條芳文, 穂積直裕, 小林和人, SANTOS FILHO Esmeraldo Dos, 田中元直, 山家智之

日本生体医工学会大会プログラム・論文集　45th　276　2006/05/15

ISSN：1347-443X
Impact of Type A behavior on brachial-ankle pulse wave velocity in Japanese Peer-reviewed

HJ Liu, Y Saijo, XM Zhang, Y Shiraishi, Y Luo, M Maruyama, M Higa, K Sekine, T Yambe

TOHOKU JOURNAL OF EXPERIMENTAL MEDICINE　209　(1)　15-21　2006/05
Publisher: TOHOKU UNIV MEDICAL PRESS
DOI： 10.1620/tjem.209.15 　

ISSN：0040-8727

eISSN：1349-3329

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Pulse wave velocity (PWV) is the velocity of a pulse wave traveling a given distance between 2 sites in the arterial system, and is a well-known indicator of arteriosclerosis. Brachial-ankle PWV (baPWV) is a parameter more simple to obtain, compared with the conventional PWV, and is an easy and effective means of evaluating arteriosclerosis. BaPWV can be obtained by only wrapping the four extremities with blood pressure cuffs, and it can be easily used to screen a large number of subjects. Type A behavior has been confirmed as an independent risk factor for the development of coronary heart disease. To examine the relationship between Type A behavior and arteriosclerosis, 307 normal Japanese subjects were classified into either a Type A group (n = 90) or a non-Type A group (n = 217) by using Maeda's Type A Scale. BaPWV was evaluated using a PWV diagnosis device. The baPWV in the Type A group was significantly higher than that obtained in the non-Type A group. The baPWV showed a positive correlation with age both in the Type A group and in the non-Type A group; however, the straight-line regression slope of baPWV versus age in the Type A group was significantly larger than that in the non-Type A group. Therefore, our results suggest that arteriosclerosis might be promoted earlier in subjects expressing the Type A behavior pattern. Type A behavior pattern is confirmed as a risk factor for arteriosclerosis, and may increase the risk of the cardiovascular disease related to arteriosclerosis. -Type A behavior; Brachial-ankle pulse wave velocity; arteriosclerosis (c) 2006 Tohoku University Medical Press.
マルファン症候群に対する心臓移植の1症例 Peer-reviewed

井口篤志, 崔, 禎浩, 齋木, 佳克, 小田, 克彦, 赤坂, 純逸, 新田, 能郎, 川本, 俊輔, 本吉, 直孝, 安達, 理, 増田, 信也, 藤原, 英記, 吉岡, 一朗, 河津, 聡, 佐藤, 真一, 小久保, 弘晶, 田林, 晄一, 柴, 信行, 二宮, 本報, 西條芳文

呼吸と循環　54　(4)　S2-S3　2006/04
音響インピーダンス顕微鏡による生体組織イメージング

木村あゆみ, 寺内智, 村上義信, 穂積直裕, 長尾雅行, 吉田祥子, 小林和人, 西条芳文

電気学会全国大会講演論文集　2006　(1)　141　2006/03/15
Comparative analysis of cardio-ankle vascular index between Japanese and Russians Peer-reviewed

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

FUTURE MEDICAL ENGINEERING BASED ON BIONANOTECHNOLOGY, PROCEEDINGS　411-+　2006
Publisher: WORLD SCIENTIFIC PUBL CO PTE LTD

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

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

FUTURE MEDICAL ENGINEERING BASED ON BIONANOTECHNOLOGY, PROCEEDINGS　557-+　2006
Publisher: WORLD SCIENTIFIC PUBL CO PTE LTD

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Artificial heart and ventricular assist devices were widely used in clinical as a therapy method to assist the severe heart failure patients. Unfortunately direct contact between the device and the patient's blood, thromboembolic events, the need for anticoagulation and infections contribute significantly to complication and mortality. Compressing the dysfunctional heart from its epicardial surface, non-blood contacting method of direct mechanical ventricular actuator compression system could provide ventricular support, pulsatile blood flow and avoid the interactions between blood and surface of artificial assistance system. We have developed an ElectroHydraulic Artificial Myocardial (EHAM) assist system that might be assist the heart muscle contraction. The purpose of this study was to determine if the EHAM system efficiency to hemodynamic parameters and myocardial tissue perfusion during its compressing in acute animal experiment. Eight adult goats were performed as acute experiments. Hemodynamic parameters were continuous monitored including ECG, aortic blood pressure, left ventricular pressure and pulmonary artery pressure. Myocardial tissue perfusion was measured by using Omega flow laser fiber attaching on the surface of the heart. The results showed that all the animals achieved significant increasing the blood pressure, pulmonary artery flow and myocardial tissue perfusion during the EHAM compressing compared with non-driving (pre-assisted) mode. In conclusions: EHAM system devices can effectively improves the myocardial tissue perfusion and increases the pressure thus having a potential for failing cardiac treatment.
637 Blood Flow Simulation Integrated with Ultrasonic Measurement : 6^<th> Report : Three-Dimensional Unsteady Blood Flow Simulation

FUNAMOTO Kenichi, HAYASE Toshiyuki, SAIJO Yoshifumi, YAMBE Tomoyuki

The proceedings of the JSME annual meeting　2006　195-196　2006
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmemecjo.2006.5.0_195 　

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Development and progress of circulatory diseases are closely related to the hemodynamics in the blood vessel. However, detailed and accurate information of blood flow field has yet to be obtained due to the limitations both in measurement and numerical simulation. Hence, we have proposed the Ultrasonic-Measurement-Integrated (UMI) simulation. In this method, feedback signals derived from the difference between measured and computed Doppler velocities are fed back to the numerical simulation. The transient and steady characteristics of the UMI simulation have been revealed. In this paper, we performed the numerical experiment aiming at the reproduction of the three-dimensional unsteady flow field. As the result, the application of the feedback in the UMI simulation made the computational results converge and trace to the model of real blood flow.
S-14 超音波による心臓・血管の中の流れの医工学的解析(特別企画II(要望演題5) 逆流性疾患・閉塞性疾患・拡張性疾患に対する治療戦略-管と流れと-,第43回日本小児外科学会総会)

西條芳文, 白石泰之, 関根一光, 山家智之, 田中元直, 田林晄一, 早瀬敏幸, 船本健一, 大槻茂雄, 菅原重生

日本小児外科学会雑誌　42　(3)　355-355　2006
Publisher: 特定非営利活動法人日本小児外科学会
DOI： 10.11164/jjsps.42.3_355_2 　
Preliminary study on the functional reproduction of an artificial myocardium using covalent shape memory alloy fibre based on control engineering Peer-reviewed

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

2006 SICE-ICASE International Joint Conference　1734-1737　2006

DOI： 10.1109/SICE.2006.315627 　

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

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

2006 IEEE ULTRASONICS SYMPOSIUM, VOLS 1-5, PROCEEDINGS　1294-+　2006
Publisher: IEEE
ISSN：1051-0117

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

Yoshihiro Hagiwara, Yoshifumi Saijo, Eiichi Chimoto, Hirotoshi Akita, Yasuyuki Sasano, Fujio Matsumoto, Shoichi Kokubun

Upsala journal of medical sciences　111　(3)　303-13　2006

ISSN：0300-9734

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OBJECTIVES: The mechanical property of immobilized joints is not well understood. The present study was designed to investigate the tissue elasticity of the anterior and posterior synovial membrane (SM) in a rat immobilized knee model using scanning acoustic microscopy (SAM). Moreover, the structural characteristics of the SM after immobilization were examined by transmission electron microscopy (TEM). METHODS: Thirty rats had their knee joints immobilized with a plate and metal screws. The rats were fixed at 1, 2, 4, 8 and 16 weeks after surgery and the knee joints were sectioned sagittally for SAM. Selected specimens were processed for TEM. A new concept SAM using a single pulsed wave instead of continuous waves was applied to measure the sound speed of the anterior and posterior SM, comparing it with the corresponding light microscopic images. RESULTS: The sound speed of the posterior SM increased significantly in the 8- and 16-week experimental group compared with that in the control group. The sound speed of the anterior SM showed no statistical difference between the experimental and the control groups at any period of immobilization. The posterior SM of the experimental group was different from that of the control group in the ultrastructural characteristics of extracellular matrices. CONCLUSIONS: Our data suggest that the increased elasticity and structural changes of the posterior SM are one of the main causes of limited extension after a long period of immobilization in flexion using SAM, which is a powerful tool for evaluating the elasticity of targeted tissues.
Development of Cerebella Tissue of Rat Characterized by Acoustic Impedance Microscope Peer-reviewed

A. Kimura, S. Terauchi, M. Nagao, S. Yoshida, K. Kobayashi, Y. Saijo, N. Hozumi

2006 IEEE ULTRASONICS SYMPOSIUM, VOLS 1-5, PROCEEDINGS　1　1421-+　2006
Publisher: IEEE
ISSN：1051-0117

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Acoustic microscopy is expected to be a powerful tool for observing biological matters without chemical staining. We have proposed a new method for two-dimensional acoustic impedance imaging for biological tissue that can perform microscale observation without preparing a sliced specimen. A tissue was attached on a 0.5 mm-thick plastic substrate. An acoustic pulse was transmitted from the rear side of the substrate. The reflection intensity was interpreted into local acoustic impedance of the target tissue. In the previous report, we demonstrated the outline of the system and the result of preliminary observation, showing its feasibility. This report deals with the optimization of the observation method, and characterization of the tissue of developing cerebellum. The result shows that change in acoustic impedance of each cerebellar layer depending on postnatal day was correspond to change of structure with growth.
Development of Ultrasonic-Measurement-Integrated Simulation System for Complex Blood flows

Takayuki Yamagata, Toshiyuki Hayase, Yoshifumi Saijo, Tomoyuki Yambe

Proceedings of the Fifth International Symposium of Advanced Fluid Information　61-62　2005/12
Effect of Ultrasound Probe Placement in Ultrasonic-Measurement-Integrated Simulation of Blood Flows Peer-reviewed

Kenichi Funamoto, Toshiyuki Hayase, Yoshifumi Saijo, Tomoyuki Yambe

Proceedings of the 12th International Conference on Biomedical Engineering (ICBME 2005)　CD-ROM　2005/12

DOI： 10.1007/s10439-005-2495-2 　
Parametric intravascular ultrasound imaging - Two-dimensional tissue velocity imaging and self-organizing map imaging. Peer-reviewed

Saijo Y, Santos Filho E, Yambe T, Tanaka A, Iwamoto T, Yoshizawa M, Akino Y, Hanadate Y

Proc 8th Sendai Symposium on Ultrasonic Tissue Characterization　1　1-4　2005/11/11
Automatic luminal contour and calcification detection in intravascular ultrasound images. Peer-reviewed

Santos Filho E, Saijo Y, Yoshizawa M, Tanaka A

Proc 8th Sendai Symposium on Ultrasonic Tissue Characterization　1　5-8　2005/11/11
Image processing for pulse driven biological microscope based on frequency spectrum. Peer-reviewed

Kimura A, Terauchi S, Murakami Y, Hozumi N, Nagao M, Yoshida S, Kobayashi K, Saijo Y

Proc 8th Sendai Symposium on Ultrasonic Tissue Characterization　1　30-31　2005/11/11
Increased sound speed of synovial membrane after immobilization assessed by scanning acoustic microscopy. Peer-reviewed

Hagiwara Y, Matsumoto F, Chimoto E, Kokubun S, Saijo Y, Sasano Y

Proc 8th Sendai Symposium on Ultrasonic Tissue Characterization　32-35　2005/11/11
Material properties of the rabbit supraspinatus tendon and its insertion - A measurement with the scanning acoustic microscopy. Peer-reviewed

Sano H, Hattori K, Kokubun S, Saijo Y

Proc 8th Sendai Symposium on Ultrasonic Tissue Characterization　1　36-38　2005/11/11

DOI： 10.1142/S021895770400117X 　
埋込み型人工心筋装置による補助循環の際の血行動態に関する検討 Peer-reviewed

王慶田, 山家智之, 白石泰之, 西條芳文, 梅津光生, 仁田新一

人工臓器　34　(2)　S-122　2005/11
超微細径アクチュエータを用いたメカトロニクス心筋の開発 Peer-reviewed

白石泰之, 山家智之, 関根一光, 金野敏, 西條芳文, 王慶田, 劉紅箭, 仁田新一, 佐藤文博, 小川大祐, 田中明, 吉澤誠, 岡本英治, 永利潤, 伊藤慎二, 植松美幸, 梅津光生, 田林晄一, 増本憲泰, 藤本哲男

人工臓器　34　(2)　S-122　2005/11
コイル状形状記憶合金による蠕動運動型人工食道の開発 Peer-reviewed

関根一光, 山家智之, 西條芳文, 白石泰之, 堀義生, 松木英敏, 佐藤文博, 角張泰之, 三浦英和, 前田剛, 仁田新一

人工臓器　34　(2)　S-116　2005/11
日本の人工臓器研究・開発に望まれるもの冠動脈バイパスグラフトの術中評価(マルチポイントドプラ法)機器の開発 Peer-reviewed

新田能郎, 西條芳文, 白石泰之, 山家智之, 若松立也, 田中元直, 田林晄一

人工臓器　34　(2)　S-49　2005/11
Publisher: None
DOI： 10.11392/jsao1972.34.2Supplement_s49 　

ISSN：0300-0818
Effect of Feedback Domain in Ultrasonic-Measurement-Integrated Simulation on Reproduction of Blood Flow Field in an Aneurysmal Aorta

Kenichi Funamoto, Toshiyuki Hayase, Yoshifumi Saijo, Tomoyuki Yambe

Proceedings of the 6th International Symposium on Future Medical Engineering based on Bio-nanotechnology (21st Century COE Program)　62-63　2005/11
マルチポイントドプラによる冠動脈バイパスグラフト吻合部の術中評価法の開発 Peer-reviewed

新田能郎, 白石泰之, 西條芳文, 山家智之, 若松立也, 田中元直, 田林晄一

The Japanese Journal of THORACIC AND CARDIOVASCULAR SURGERY　53　(Suppl.II)　336-336　2005/09
Moment-based texture segmentation of luminal contour in intravascular ultrasound images Peer-reviewed

Esmeraldo Dos Santos Filho, Makoto Yoshizawa, Akira Tanaka, Yoshifumi Saijo, Takahiro Iwamoto

Journal of Medical Ultrasonics　32　(3)　91-99　2005/09

DOI： 10.1007/s10396-005-0041-3 　

ISSN：1346-4523 1613-2254

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Purpose. A system for luminal contour segmentation in intravascular ultrasound images is proposed. Methods. Moment-based texture features are used for clustering of the pixels in the input image. After the clustering, morphological smoothing and a boundary detection process are applied and the final image is obtained. Results. The proposed method was applied to 15 images from different patients, and a correlation coefficient of 0.86 was obtained between the areas of lumen automatically and manually defined. Conclusion. Moment-based texture features together with the radial feature are powerful tools for identification of the lumen region in intravascular ultrasound images. Morphological filtering was useful for improving the segmentation results. © The Japan Society of Ultrasonics in Medicine 2005.
Influence of aging on cardiac function examined by echocardiography Peer-reviewed

S Watanabe, N Suzuki, A Kudo, T Suzuki, S Abe, M Suzuki, S Komatsu, Y Saijo, N Murayama

TOHOKU JOURNAL OF EXPERIMENTAL MEDICINE　207　(1)　13-19　2005/09
Publisher: TOHOKU UNIV MEDICAL PRESS
DOI： 10.1620/tjem.207.13 　

ISSN：0040-8727

eISSN：1349-3329

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We assessed the influence of aging on cardiac function by means of parameters measured by echocardiography. The study group consisted of 494 normal subjects aged 13 to 87 years. We measured the ratio of early filling (E) and atrial contraction (A) transmittal flow velocities (E/A) of left and right ventricular inflow (LV E/A and RV E/A) for assessment of diastolic function. We also measured left ventricular ejection fraction (LVEF), and the ratio of pre-ejection period (PEP) and ejection time (ET) of the left ventricle (PEP/ET) for assessment of systolic function. Both LV E/A and RV E/A decreased significantly with aging while LVEF and PEP/ET remained normal range. The decline rate as aging was greater in LV E/A than in RV E/A. These results showed that both left and right ventricular diastolic function deteriorated with aging while left ventricular systolic function was not noticeably affected by aging. We suggest that indexes of diastolic function are more sensitive than those of systolic function when the natural course is studied in a large population.
完全埋込型心室補助装置による循環補助 Peer-reviewed

白石泰之, 山家智之, 関根一光, 西條芳文, 堀義生, 桑山貴志, 小川大祐, 田中明, 吉澤誠, 佐藤文博, 松木英敏, 羅雲, 高木敏行, 比嘉昌, 伊吹竜太, 圓山重直, 岡本英治, 青木秀宜, 永利潤, 伊藤慎二, 梅津光生, 佐々田比呂志, 王慶田, 段旭東, 劉紅箭, 仁田新一, 田林晄一

生体医工学　43　(2)　328-328　2005/06
Ultrasonic-Measurement-Integrated Simulation for Reproduction of Three-Dimensional Blood Flow Field in the Aorta with Aneurysm

Kenichi Funamoto, Toshiyuki Hayase, Yoshifumi Saijo, Tomoyuki Yambe

Proceedings of ASME 2005 Summer Bioengineering Conference　CD-ROM　2005/06
An innovative approach to evaluate a cardiac function based on surface measurement. Peer-reviewed

Uematsu M, Shiraishi Y, Sekine K, Yambe T, Saijo Y, Park Y, Ando H, Matsumoto T, Takeda S, Iwasaki K, Umezu M

Conf Proc IEEE Eng Med Biol Soc　7　7640-7643　2005/04
Development of an Artificial Myocardium using a Covalent Shape-memory Alloy Fiber and its Cardiovascular Diagnostic Response. Peer-reviewed

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

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

DOI： 10.1109/IEMBS.2005.1616431 　

ISSN：0589-1019

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The authors have been developing a newly-designed totally-implantable artificial myocardium using a covalent shape-memory alloy fibre (Biometal®, Toki Corporation), which is attached onto the ventricular wall and is also capable of supporting the natural ventricular contraction. This mechanical system consists of a contraction assistive device, which is made of Ti-Ni alloy. And the phenomenon of the martensitic transformation of the alloy was employed to achieve the physiologic motion of the device. The diameter of the alloy wire could be selected from 45 to 250μm. In this study, the basic characteristics of the fiber of 150μm was examined to design the sophisticated mechano-electric myocardium. The stress generated by the fiber was 400gf under the pulsatile driving condition (0.4W, 1Hz). Therefore it was indicated that the effective assistance might be achieved by using the Biometal shape-memory alloy fiber. © 2005 IEEE.
Fundamental study of ultrasonic-measurement-integrated simulation of real blood flow in the aorta Peer-reviewed

Kenichi Funamoto, Toshiyuki Hayase, Atsushi Shirai, Yoshifumi Saijo, Tomoyuki Yambe

Annals of Biomedical Engineering　33　(4)　415-428　2005/04

DOI： 10.1007/s10439-005-2495-2 　

ISSN：0090-6964

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Acquisition of detailed information on the velocity and pressure fields of the blood flow is essential to achieve accurate diagnosis or treatment for serious circulatory diseases such as aortic aneurysms. A possible way to obtain such information is integration of numerical simulation and color Doppler ultrasonography in the framework of a flow observer. This methodology, namely, Ultrasonic-Measurement-Integrated (UMI) Simulation, consists of the following processes. At each time step of numerical simulation, the difference between the measurable output signal and the signal indicated by numerical simulation is evaluated. Feedback signals are generated from the difference, and numerical simulation is updated applying the feedback signal to compensate for the difference. This paper deals with a numerical study on the fundamental characteristics of UMI simulation using a simple two-dimensional model problem for the blood flow in an aorta with an aneurysm. The effect of the number of feedback points and the feedback formula are investigated systematically. It is revealed that the result of UMI simulation in the feedback domain rapidly converges to the standard solution, even with usually inevitable incorrect upstream boundary conditions. Finally, an example of UMI simulation with feedback from real color Doppler measurement also shows a good agreement with measurement. © 2005 Biomedical Engineering Society.
フーリエ変換型超音波顕微鏡の解析アルゴリズムの精度評価に関する研究 III

青柳美広, LEE Cheol‐Kyou, 穂積直裕, 長尾雅行, 小林和人, 西条芳文

電気学会全国大会講演論文集　2005　(1)　143　2005/03/17
超音波顕微鏡による生体組織の音響パラメータ取得に関する検討

LEE Cheol‐Kyou, 村上義信, 穂積直裕, 長尾雅行, 小林和人, 西条芳文

電気学会全国大会講演論文集　2005　(1)　142　2005/03/17
Estimation of echo amplitude in pulsed ultrasonic microscopy

TANAKA N, KOBAYASHI K, HOZUMI N, SAIJO Y, TANAKA M, OHTSUKI S

日本音響学会研究発表会講演論文集　2005　(1)　721-722　2005/03/08

ISSN：1340-3168
Artificial esophagus with peristaltic movement. Peer-reviewed

Watanabe Makoto, Sekine Kazumitsu, Hori Yoshio, Shiraishi Yasuyuki, Maeda Takeshi, Honma Dai, Miyata Go, Saijo Yoshifumi, Yambe Tomoyuki

ASAIO J　51　(2)　158-161　2005/03

DOI： 10.1097/01.MAT.0000154644.44891.F1 　
Improvement of the Precision of Ultrasonic Microscope for Biological Tissue Using the Automatic Extraction of the Reference Signals Peer-reviewed

LEE Cheol-Kyou, MURAKAMI Yoshinobu, HOZUMI Naohiro, NAGAO Masayuki, KOBAYASHI Kazuto, SAIJO Yoshifumi, TANAKA Naohiko, OHTSUKI Shigeo

IEEJ Transactions on Fundamentals and Materials　125-A　(2)　145-152　2005/02/01
Publisher: The Institute of Electrical Engineers of Japan
DOI： 10.1541/ieejfms.125.145 　

ISSN：0385-4205

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This paper deals with the precision of the ultrasonic microscopy for biological tissue characterization. The estimation error of sound speed influenced by the selection of reference points for obtaining the reference signal is described. In well known scanning type microscope, a focused ultrasonic signal is irradiated to the glass substrate on which a thin sliced tissue is attached. The reflected signal from the front surface of the tissue is compared with the signal from the glass substrate on which no tissue is attached. As the scanning plane and glass substrate are not completely in parallel, it is necessary to locate the glass surface at each measuring point. For this purpose, several reference points on which no tissue is attached are selected in the view field. The equation of the plane representing the glass surface is consequently obtained using the reflection at these reference points. However, the glass surface has an apparent surface roughness. This brings an estimation error of the equation of the plane. This error can be reduced by increasing the number of reference points. In order to extract a sufficient number of reference points automatically, an algorithm using the reflected wave was proposed to discriminate the points where the glass surface is exposed. Although the estimation error of sound speed with three reference points was as large as 31 m/s (as the double of standard deviation), it was reduced into as small as 16 m/s, when 1000 reference points had been automatically extracted.
Effect of Density of Monitoring Points for Feedback in Ultrasonic-Measurement-Integrated Simulation of Blood Flow in the Aorta with Aneurysm Peer-reviewed

Kenichi Funamoto, Toshiyuki Hayase, Yoshifumi Saijo, Tomoyuki Yambe

Proceedings of the 3rd IASTED International Conference on Biomedical Engineering (BioMED2005)　118-123　2005/02
1108 Blood Flow Simulation Integrated with Ultrasonic Measurement : 4^<th> Report: Improvement of Accuracy of Computational Hemodynamics

FUNAMOTO Kenichi, HAYASE Toshiyuki, SAIJO Yoshifumi, YAMBE Tomoyuki

The proceedings of the JSME annual meeting　2005　89-90　2005
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmemecjo.2005.5.0_89 　

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

FUNAMOTO Kenichi, HAYASE Toshiyuki, SAIJO Yoshifumi, YAMBE Tomoyuki

Proceedings of the JSME Bioengineering Conference and Seminar　2004　151-152　2005
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmebs.2004.17.0_151 　
Detection of luminal contour using fuzzy clustering and mathematical morphology in intravascular ultrasound images Peer-reviewed

Esmeraldo Dos Santos Filho, Makoto Yoshizawa, Akira Tanaka, Yoshifumi Saijo, Takahiro Iwamoto

2005 27th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, Vols 1-7　3471-3474　2005
Publisher: IEEE
ISSN：1094-687X

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An innovative application of fuzzy clustering and mathematical morphology for the problem of luminal contour detection in intravascular ultrasound images is presented. Median and standard deviation are used as features for segmentation process. Comparison was made with gold standard segmented images obtained from the average of images segmented by experienced medical doctors. Tests were carried out with 20 in vivo coronary images obtained from different patients. High correlation coefficients were found between lumen regions manually and automatically defined when area, mean gray level, and standard deviation of the lumen regions were compared.
Coronary plaque classification through intravascular ultrasound radiofrequency data analysis using self-organizing map Peer-reviewed

T Iwamoto, A Tanaka, Y Saijo, M Yoshizawa

2005 IEEE Ultrasonics Symposium, Vols 1-4　2054-2057　2005
Publisher: IEEE
ISSN：1051-0117

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Intravascular ultrasound (IVUS) is an important clinical tool in the assessment of atherosclerotic plaque in coronary artery diseases. Using IVUS, we can obtain high resolution echo image of cross-sections of the coronary artery. However, it is difficult to accurately classify plaques by using the echogram only. We propose a method of IVUS Radiofrequency (RF) signal classification using self-organizing map (SOM). Characteristic ROIs (region of interest) of the IVUS echogram of patients with coronary lesions were selected by an expert medical doctor, and the SOM learned from these ROIs. The SOM could classify the RF signals with accuracies of 95.9% for fibrous plaque, 99.5% for blood, 96.2% for calcified plaque and 16.3% for media regions. This result suggests that the proposed technique is useful for automatic characterization of plaque in coronary artery.
508 Development of a totally implantable artificial myocardial assist system : Preliminary study of the hemodynamic effect in the mock circulatory system and in animal experiment

AOKI Hidetaka, NITTA Shin-ichi, OKAMOTO Eiji, OGAWA Daisnke, YOSHIZAWA Makoto, TANAKA Akira, TANAKA Takashi, SASADA Hiroshi, TABAYASHI Koichi, HOMMA Dai, NAGATOSHI Jun, ITOH Shinji, SUDO Tomohiro, UMEZU Mitsuo, SHIRAISHI Yasuyuki, SEKINE Kazumitsu, SAIJO Yoshifumi, YAMBE Tomoyuki

Proceedings of the JSME Bioengineering Conference and Seminar　2004　(0)　191-192　2005
Publisher: 一般社団法人日本機械学会
DOI： 10.1299/jsmebs.2004.17.0_191 　
Detection of luminal contour using fuzzy clustering and mathematical morphology in intravascular ultrasound images. Peer-reviewed

Dos Santos E, Yoshizawa M, Tanaka A, Saijo Y, Iwamoto T

Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference　4　3471-3474　2005

DOI： 10.1109/IEMBS.2005.1617226 　

ISSN：1557-170X
生体組織診断のためのパルス励起型音速顕微鏡の開発 Peer-reviewed

小林和人, 穂積直裕, 西條芳文, 大槻茂雄

日本音響学会誌　44　(1.1)　e51-e55　2005
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
Detection and correction of aliasing in ultrasonic measurement of blood flows with Ultrasonic-Measurement-Integrated simulation Peer-reviewed

Kenichi Funamoto, Toshiyuki Hayase, Yoshifumi Saijo, Tomoyuki Yambe

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

ISSN：0928-7329

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

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

Technology and health care : official journal of the European Society for Engineering and Medicine　13　(4)　261-7　2005

ISSN：0928-7329

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Since 1985, we have been developing a scanning acoustic microscope (SAM) system for biomedical use and have been investigating the acoustic properties of various organs and disease states by using this SAM system. In biomedicine, SAM is useful for intraoperative pathological examination, study of low-frequency ultrasonic images, and assessment of biomechanics at a microscopic level. Recently, we have proposed a new concept -- acoustic microscopy -- using a single pulsed wave instead of continuous waves used in conventional SAM systems. In the present study, we compared two systems by measuring the same biological material. The sound speed image obtained by sound speed microscopy corresponded well to that obtained using a conventional SAM system. Lesions with hyaline degeneration showed a lower sound speed when compared with that of normal myocardium. Frequency domain analysis of amplitude and phase by both methods also showed similar characteristics. Although the data acquisition time of one frame was greater than that in conventional SAM, the total time required for calculation was significantly shorter. The SAM system can be applied to intraoperative pathological examination.
Speed of sound microscopy for biomedical applications Peer-reviewed

Y. Saijo, H. Sasaki, T. Yambe, M. Tanaka, N. Hozumi, K. Kobayashi, N. Okada

Proceedings - IEEE Ultrasonics Symposium　1　419-422　2005

DOI： 10.1109/ULTSYM.2005.1602883 　

ISSN：1051-0117

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We have been developing a scanning acoustic microscope (SAM) system for medicine and biology featuring quantitative measurement of ultrasonic speed and attenuation of soft tissues. In the present study, we will propose a new concept ultrasonic speed microscopy that can measure the thickness and ultrasonic speed using fast Fourier transform of a single pulsed wave instead of continuous waves used in conventional SAM systems. Six coronary arteries were frozen and sectioned approximately 10 μm in thickness. They were mounted on glass slides without cover slips. The scanning time of a frame with 300×300 pixels was 90 s and two-dimensional distribution of speed of sound was obtained. The speed of sound was 1720 m/s in the thickened intima with collagen fiber, 1520 m/s in lipid deposition underlying fibrous cap and 1830m/s in calcified lesion in the intima. These basic measurements will help understanding echo intensity and pattern in intravascular ultrasound (IVUS) images. © 2005 IEEE.
Acoustic impedance micro-imaging for biological tissue using a focused acoustic pulse with a frequency range up to 100 MHz Peer-reviewed

N Hozumi, A Kimura, S Terauchi, M Nagao, S Yoshida, K Kobayashi, Y Saijo

2005 IEEE Ultrasonics Symposium, Vols 1-4　170-173　2005
Publisher: IEEE
DOI： 10.1109/ULTSYM.2005.1602823 　

ISSN：1051-0117

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We have proposed a new method for two-dimensional acoustic impedance imaging for biological tissue that can perform micro-scale observation without slicing the specimen. A tissue was placed on a plastic plate of 0.5 mm in thickness. An acoustic pulse with a frequency range up to 100 MHz was transmitted from the "rear side" of the plate, the acoustic beam being focused at the boundary between the tissue and plate. The reflection intensity was interpreted into local acoustic impedance of the target tissue. An acoustic impedance microscopy with 200 x 200 pixels, its field of view being 2 x 2 mm, was obtained by mechanically scanning the transducer. Quantification of acoustic impedance was performed using water or an appropriate material as a reference The accuracy was evaluated using saline with various NaCl content. A rat cerebellum was employed as the specimen. The development of parallel fiber in cerebella cultures was clearly observed as the contrast in acoustic impedance. The proposed technique is believed to be a powerful tool for biological tissue characterization, as neither staining nor slicing is required.
Speed of sound microscopy for biomedical applications Peer-reviewed

Y Saijo, H Sasaki, T Yambe, M Tanaka

2005 IEEE Ultrasonics Symposium, Vols 1-4　423-426　2005
Publisher: IEEE
DOI： 10.1109/ULTSYM.2005.1602883 　

ISSN：1051-0117

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We have been developing a scanning acoustic microscope (SAM) system for medicine and biology featuring quantitative measurement of ultrasonic speed and attenuation of soft tissues. In the present study, we will propose a new concept ultrasonic speed microscopy that can measure the thickness and ultrasonic speed using fast Fourier transform of a single pulsed wave instead of continuous waves used in conventional SAM systems. Six coronary arteries were frozen and sectioned approximately 10 mu m in thickness. They were mounted on glass slides without cover slips. The scanning time of a frame with 300x300 pixels was 90 s and two-dimensional distribution of speed of sound was obtained. The speed of sound was 1720 m/s in the thickened intima with collagen fiber, 1520 m/s in lipid deposition underlying fibrous cap and 1830m/s in calcified lesion in the intima. These basic measurements Will help understanding echo intensity and pattern in intravascular ultrasound (IVUS) images.
形状記憶合金を用いた蠕動運動型人工食道の開発 Peer-reviewed

関根一光, 山家智之, 西條芳文, 白石泰之

加齢医学研究所雑誌　56　(1)　37-37　2004/11
Basic ultrasonic characteristics of atherosclerosis measured by intravascular ultrasound and acoustic microscopy Peer-reviewed

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

International Congress Series　1274　116-121　2004/10

DOI： 10.1016/j.ics.2004.07.009 　
Addition of rhythm to non-pulsatile circulation Peer-reviewed

T Yambe, K Sekine, Y Shiraishi, M Watanabe, M Shibata, T Yamaguchi, QT Wang, XD Duan, HJ Liu, M Yoshizawa, A Tanaka, H Matsuki, F Sato, YI Haga, M Esashi, K Tabayashi, Y Mitamura, H Sasada, E Sato, Y Saijo, S Nitta

BIOMEDICINE & PHARMACOTHERAPY　58　S145-S149　2004/10
Publisher: EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER
DOI： 10.1016/S0753-3322(04)80024-6 　

ISSN：0753-3322

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The development of a rotary blood pump (RP) is desirable as it can be used as a small ventricular assistance device (VAD). However, a RP does not generate any pulse. It may be physiologically better for the patient if the RP could generate a pulse. We have attempted to develop a device that produces a pulse in the RP. Intra-aortic balloon pumping (IABP) is effective in producing a pulse. However, the IABP cannot be implanted inside the body. Therefore, an attempt was made to develop pulse-generating equipment that was not driven by air pressure. The ball screw motor was considered as a possible candidate. In the future, we plan to apply small shape memory alloys. An electrohydraulic system was adopted, and actuator power output was connected to the diaphragm. The diaphragm was placed outside the ventricle. Most RPs developed throughout the world drain blood from the ventricle. The pulse wave should be generated if a pulse is added by the part from which blood is being drawn. In this study, animal experiments were conducted and the output assistance was tested from outside the ventricle. The device operated effectively in the animal experiment. The RP can easily be equipped with this device at the time of performing the implant operation. For a patient with problems of peripheral circulation and the internal organ fiunction, it may prove to be an effective device.
Brachio-ankle pulse wave velocity and cardio-ankle vascular index (CAVI) Peer-reviewed

T Yambe, M Yoshizawa, Y Saijo, T Yamaguchi, M Shibata, S Konno, S Nitta, T Kuwayama

BIOMEDICINE & PHARMACOTHERAPY　58　S95-S98　2004/10
Publisher: EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER
DOI： 10.1016/S0753-3322(04)80015-5 　

ISSN：0753-3322

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In order to diagnose arteriosclerosis in any part of the body, pulse wave velocity (PWV) measurement is a useful approach. However, it is considered that the technique of PWV measurement should be simplified. A new method for measuring PWV has therefore been proposed in Japan. The PWV of the brachial artery (ba) and the ankle was measured by applying air pressure with the aid of a volume plethysmograph. Comparisons between the baPWV measurement method and the conventional method are currently being performed. Since satisfactory results have been obtained to date, baPWV has gained popularity throughout Japan. Since this method measures PWV in the arm and foot, it may be said that aortic PWV is not reflected though a large amount of past PWV measurements. BaPWV is influenced by blood pressure. With the baPWV technique, blood pressure compensation is not carried out. Furthermore, the pulse pressure is measured by air pressure; therefore any stimulus that exerts pressure on an artery may influence these results. Due to these reasons, a cardio-ankle vascular index (CAVI) has been proposed in which the pressure wave form indicating the closing of the aortic valve appears in the form of an arterial pressure wave after a fixed delay time. This delay is the time difference between the actual closing of the aortic valve and the measuring point. Prior to the introduction of baPWV, PWV was measured in the carotid artery and foot. As in traditional PWV, baPWV uses the delay time, but between the brachial artery and the ankle artery. However, the carotid artery differs from the brachial artery, and the measured value differs depending on whether the arteriosclerosis is present in the carotid artery or the brachial artery. CAVI is calculated from the ECG, PCG, brachial artery waveform and ankle artery waveform using a special algorithm. This new method represents a breakthrough in the diagnosis of atherosclerosis. (C) 2004 Elsevier SAS. All rights reserved.
A Japanese-Russian collaborative study on aging and atherosclerosis Peer-reviewed

T Yambe, YA Kovalev, IA Milyagina, VA Milyagin, Y Shiraishi, M Yoshizawa, Y Saijo, T Yamaguchi, M Shibata, S Nitta

BIOMEDICINE & PHARMACOTHERAPY　58　S91-S94　2004/10
Publisher: EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER
DOI： 10.1016/S0753-3322(04)80014-3 　

ISSN：0753-3322

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In Russia, the average life span is decreasing. This phenomenon has not been previously observed in the western hemisphere during periods of relative peace. Although this trend can be attributed to various causes, the available statistics suggest that approximately 55% of the total mortality in Russia at the present time is due to cardiovascular events. Similarly, cardiovascular events are also increasing in Japan and are associated with changes in eating habits. A Japanese-Russian international collaborative study was therefore initiated to investigate this. Data on 102 normal Russian subjects were obtained from a total of 345 patients treated at the Smolensk State Medical Academy outpatients' clinic. The data on the Japanese patients were collected at Tohoku University, Tohoku Rosai Hospital, and Fukuda Denshi Company. Sixty-seven healthy male Japanese volunteers were compared with 44 healthy male Russian patients. In this study, Vasera VS 1000 (Fukuda Denshi, Tokyo) was utilized to measure pulse wave velocity (PWV). Linear regression analysis was performed, and the results showed that brachial-ankle PWV (baPWV) was significantly higher in the Russian compared with the Japanese study group. With regard to aging, PWV,was found to increase both in the Japanese and Russian subjects, with a significant increase in the latter group during their 40s compared with the Japanese, and with this tendency being carried forward into the 50s. This may be the principal cause for the higher incidence of cardiovascular events reported among Russians. Furthermore, when a straight line regression analysis was performed, the zero axis intercept in both cases showed almost the same value. These results indicated that the PWV may be almost the same in Japanese and Russian populations at the time of birth. In conclusion, at the time of birth, there is no difference in the atherosclerotic status of Japanese and Russian infants. However, overtime atherosclerosis becomes more apparent and progresses significantly in the case of Russian subjects. This finding is observed through the analysis of PWV. The present authors intend to continue their study aimed at preventing the further development of atherosclerosis through medical intervention. (C) 2004 Elsevier SAS. All rights reserved.
超音波音速顕微鏡のための多成分エコー推定法

田中直彦, 小林和人, 穂積直裕, 西条芳文, 田中元直, 大槻茂雄

日本音響学会研究発表会講演論文集　2004　1359-1360　2004/09/21

ISSN：1340-3168
形状記憶合金「バイオメタル」を用いた蠕動運動型人工食道の開発研究 Peer-reviewed

関根一光, 山家智之, 西條芳文, 白石泰之, 堀義生, 松木英敏, 佐藤文博, 本間大, 前田剛

人工臓器　33　(2)　S221-S221　2004/09
完全埋込を目指した人工心室補助装置の血行力学的影響慢性動物実験における心収縮補助効果の検討 Peer-reviewed

白石泰之, 山家智之, 岡本英治, 関根一光, 小川大祐, ポール・オレガリオ, 吉澤誠, 青木秀宜, 永利潤, 伊藤慎二, 田中明, 佐藤文博, 西條芳文, 王慶田, 圓山重直, 早瀬敏幸, 松木英敏, 本間大, 梅津光生, 仁田新一

人工臓器　33　(2)　S193-S193　2004/09
Paclitaxel prevents loss of pulmonary endothelial barrier integrity during cold preservation Peer-reviewed

S Suzuki, B Hao, T Sugawara, Y Matsuda, T Tabata, Y Hoshikawa, Y Saijo, T Kondo

TRANSPLANTATION　78　(4)　524-529　2004/08
Publisher: LIPPINCOTT WILLIAMS & WILKINS
DOI： 10.1097/01.TP.0000131951.72851.57 　

ISSN：0041-1337

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Background. Cold preservation is the most practical method to maintain the viability of isolated lungs. However, rapid cooling may affect pulmonary endothelial function. We examined the effects of microtubule stabilization with paclitaxel on pulmonary endothelial barrier integrity under cold temperature. Methods. Human pulmonary arterial endothelial cells were incubated at VC for 2 hr in the presence or absence of paclitaxel (2.5 mumol/L). Microtubules was visualized using immunocytochemical techniques. Ultrasonic attenuation was measured with scanning acoustic microscopy. Endothelial barrier integrity was measured as transendothelial electric resistance. In addition, we examined graft function in a rat lung transplantation model, in which the donor lung had been preserved in the presence of paclitaxel (2.5 mumol/L) at 4degreesC for 12 hr. Results. Low temperature caused a reversible microtubule disassembly, but the structure of microtubules was preserved by paclitaxel. Paclitaxel prevented the cooling-induced decrease in ultrasonic attenuation and transendothelial electric resistance. In a rat transplantation model, we found that preservation with paclitaxel successfully improved the oxygenation performance of the donor lung, which demonstrated only mild congestion and less significant interstitial edema without fluid accumulation in the alveolar spaces. Conclusions. Our results indicate that microtubule stabilization with paclitaxel maybe beneficial to prevent the loss of the endothelial barrier during cold preservation. We conclude that the use of paclitaxel in organ preservation solutions is useful in protecting pulmonary endothelial barrier integrity during cold preservation, thereby reducing the occurrence of early graft failure.
Application of Ultrasonic-Measurement-Integrated Simulation to Blood Flow

Kenichi Funamoto, Toshiyuki Hayase, Atsushi Shirai, Yoshifumi Saijo, Tomoyuki Yambe

Proceedings of the 4th International Symposium on Future Medical Engineering based on Bio-nanotechnology　78-79　2004/06
Development of the Pulse driven ultrasonic sound speed microscopy Peer-reviewed

KOBAYASHI Kazuto, SAIJO Yoshifumi, HOZUMI Naohiro, TANAKA Naohiko, OHTSUKI Shigeo

Journal of medical ultrasonics = 超音波医学　31　717-722　2004/04/15

DOI： 10.1016/j.ultras.2003.11.005 　

ISSN：1346-1176
Tissue velocity imaging of coronary artery by rotating-type intravascular ultrasound Peer-reviewed

Y Saijo, S Tanaka, N Owada, Y Akino, S Nitta

ULTRASONICS　42　(1-9)　753-757　2004/04
Publisher: ELSEVIER SCIENCE BV
DOI： 10.1016/j.ultras.2003.11.022 　

ISSN：0041-624X

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Intravascular ultrasound (IVUS) provides not only the dimensions of coronary artery but the information of tissue components. In catheterization laboratory, soft and hard plaques are classified by visual inspection of echo intensity. So-called soft plaque contains lipid core or thrombus and it is believed to be more vulnerable than a hard plaque. However, it is not simple to analyze the echo signals quantitatively. When we look at a reflection signal, the intensity is affected by the distance of the object, the medium between transducer and objects and the fluctuation caused by rotation of IVUS probe. The time of flight is also affected by the sound speed of the medium and Doppler shift caused by tissue motion but usually those can be neglected. Thus, the analysis of RF signal in time domain can be more quantitative than intensity of RF signal. In the present study, a novel imaging technique called "intravascular tissue velocity imaging" was developed for searching a Vulnerable plaque. Radio-frequency (RF) signal from a clinically used IVUS apparatus was digitized at 500 MSa/s and stored in a workstation. First, non-uniform rotation was corrected by maximizing the correlation coefficient of circumferential RE signal distribution in two consecutive frames. Then, the correlation and displacement were calculated by analyzing the radial difference of RF signal. Tissue velocity was determined by the displacement and the frame rate. The correlation image of normal and atherosclerotic coronary arteries clearly showed the internal and external borders of arterial wall. Soft plaque with low echo area in the intima showed high velocity while the calcified lesion showed the very low tissue velocity. This technique provides important information Oil tissue character of coronary artery. (C) 2003 Elsevier B.V. All rights reserved.
Time-frequency analysis for pulse driven ultrasonic microscopy for biological tissue characterization Peer-reviewed

N Hozumi, R Yamashita, CK Lee, M Nagao, K Kobayashi, Y Saijo, M Tanaka, N Tanaka, S Ohtsuki

ULTRASONICS　42　(1-9)　717-722　2004/04
Publisher: ELSEVIER SCIENCE BV
DOI： 10.1016/j.ultras.2003.11.005 　

ISSN：0041-624X

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The authors have proposed a new type of ultrasonic microscopy for biological tissue characterization. The system is driven by a nanosecond pulse voltage, the generated acoustic wave being reflected at the front and rear side of the sliced tissue. In this report, a time-frequency analysis was applied to determine the sound speed thorough the tissue. Frequency dependence of sound speed was obtained with a myocardium of a rat sliced into 10 mum. As the reflected waveform had a significant amount of oscillating component, the waveform was once subjected to the deconvolution process. As the result, two reflections were clearly separated in time domain. Then these two reflections were separately analyzed by time-frequency analysis. Each reflection was extracted by using a proper window function. Phase angles of these reflections at the same frequency were compared. A sound speed micrograph at an arbitrary frequency in between 50 and 150 MHz was successfully obtained. A tendency was found that the sound speed slightly increases with frequency. (C) 2003 Elsevier B.V. All rights reserved.
Development of an ultra-portable echo device connected to USB port Peer-reviewed

Y Saijo, S Nitta, K Kobayashi, H Arai, Y Nemoto

ULTRASONICS　42　(1-9)　699-703　2004/04
Publisher: ELSEVIER SCIENCE BV
DOI： 10.1016/j.ultras.2003.11.009 　

ISSN：0041-624X

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In practical cardiology, a stethoscope based auscultation has been used to reveal the patient's clinical status. Recently, several hand-held echo devices are going on market and they are expected to play a role as "visible" auscultation instead of stethoscope. We have developed a portable and inexpensive echo device which can be used for screening of cardiac function. Two single element transducers were attached 180degrees apart to a rotor with 14-mm diameter. The mechanical scanner, integrated circuits for transmitting and receiving ultrasonic signals and an A/D converter were encapsulated in a 150x40 mm probe weighing 200 g. The scan was started and the image was displayed on a Windows based personal computer (PC) as soon as the probe was connected to USB 2.0 port of the PC. The central frequency was available between 2.5 and 7.5 MHz, the image depth was 15 cm and the frame rate was 30/s. The estimated price of this ultra-portable ultrasound is about 3000 US$ with software. For 69 cardiac patients with informed consent, image quality was compared with those obtained with basic range diagnostic echo machines. Left ventricular ejection fraction (EF) derived from normal M-mode image of standard machines (EFm) were compared with visual EF of the ultra-portable ultrasound device (EFv). The image quality was comparable to the basic range diagnostic echo machines although short axis view of aortic root was not clearly visualized because the probe was too large for intercostal approach. EFv agreed well with EFm. The ultra-portable ultrasound may provide useful information on screening and health care. (C) 2003 Elsevier B.V. All rights reserved.
Acoustic properties of aortic aneurysm obtained with scanning acoustic microscopy Peer-reviewed

Y Saijo, T Miyakawa, H Sasaki, M Tanaka, S Nitta

ULTRASONICS　42　(1-9)　695-698　2004/04
Publisher: ELSEVIER SCIENCE BV
DOI： 10.1016/j.ultras.2003.11.023 　

ISSN：0041-624X

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In aortic aneurysm tissues, macrophages and their secretion of matrix metalloproteinases (MMPs) are playing important role for tissue degeneration. Some studies have shown that weakening of the mechanical properties of the degenerated tissues may progress the expansion of the aneurysm. However, actual measurement of the mechanical properties has not been investigated at microscopic level. The objective of the present study is to assess the mechanical properties of aortic aneurysm tissues by measuring acoustic properties by scanning acoustic microscopy (SAM). Twenty-one cases of aortic aneurysm including renal and common iliac aneurysm tissues were surgically excised. Each tissue was fixed by 4% formaldehyde and the specimens were treated as (1) picrosirius red staining for normal and polarized light microscopy, (2) CD68 staining for macrophage detection, and (3) no staining for acoustic microscopy. A specially developed SAM system operating in the frequency range of 100-200 MHz, was employed in the measurement. Images of amplitude and phase are obtained in a field of 2x2 mm. The intima was mainly consisted of degenerated collagen without polarization of picrosirius red staining. Macrophages stained by CD68 were observed near the degenerated collagen fibers. The sound speed was 1567 m/s in the intima, 1576 m/s in the media, 1640 m/s in the adventitia, respectively. Infiltration of macrophages showed higher values of attenuation and sound speed than the surrounding tissues. The sound speed of the intima was significantly lower than our previous measurement of atherosclerotic aorta without aneurismal change. As the tissue elasticity is closely correlated with the sound speed, the elasticity of the intima was considered to be lower in aneurysm tissues. This mechanical weakness may contribute to the expansion of the diameter of the aneurysm. Acoustic microscopy provided important data for assessing tissue mechanical properties of abdominal aneurysm. (C) 2003 Elsevier B.V. All rights reserved.
医用フーリエ変換型超音波顕微鏡の精度評価(III)

長江理都子, LEE C K, 村上義信, 穂積直裕, 長尾雅行, 小林和人, 西条芳文

電気学会全国大会講演論文集　2004　(1)　17　2004/03/17
参照点の自動抽出によるフーリエ変換型超音波顕微鏡の高精度化に関する検討

LEE C K, 長江理都子, 村上義信, 穂積直裕, 長尾雅行, 田中直彦, 小林和人, 西条芳文

電気学会全国大会講演論文集　2004　(1)　160　2004/03/17
Improvement of the Precision of Fourier Transform Ultrasonic Microscope for Biological Tissue Using the Automatic Extraction of the Reference Signals

LEE C. K, HOZUMI N, NAGAO M, KOBAYASHI K, SAIJO Y, TANAKA N, OOTSUKI S, MURAKAMI Y

日本音響学会研究発表会講演論文集　2004　(1)　1091-1092　2004/03/17

ISSN：1340-3168
Spatial Resolution of Pulse-driven Ultrasonic Microscopy for Biological Tissue Characterization Inspected by 2D-FFT Image Processing

KOBAYASHI K, NAGAE R, HOZUMI N, SAIJO Y, TANAKA N, OTSUKI S

日本音響学会研究発表会講演論文集　2004　(1)　1093-1094　2004/03/17

ISSN：1340-3168
A simple estimation of sound speed considering multiple echo components in ultrasonic microscopy

TANAKA N, KOBAYASHI K, HOZUMI N, SAIJO Y, TANAKA M, OHTSUKI S

日本音響学会研究発表会講演論文集　2004　(1)　1095-1096　2004/03/17

ISSN：1340-3168
フーリエ変換型超音波顕微鏡の解析アルゴリズムの精度評価に関する検討

青柳美広, LEE C‐K, 長江理都子, 穂積直裕, 長尾雅行, 小林和人, 西条芳文

電気学会全国大会講演論文集　2004　(1)　186　2004/03/17
Material properties of the supraspinatus tendon at its insertion - A measurement with the scanning acoustic microscopy Peer-reviewed

Hirotaka Sano, Yoshifumi Saijo, Shoichi Kokubun

Journal of Musculoskeletal Research　8　(1)　29-34　2004/03

DOI： 10.1142/S021895770400117X 　

ISSN：0218-9577

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The acoustic properties of the supraspinatus tendon insertions of three adult Japanese white rabbits (male, 3.2-3.5 kg) were measured by scanning acoustic microscopy (SAM). After cutting parallel to the supraspinatus tendon fibers, specimens were fixed with 10% neutralized formalin, embedded in paraffin and sectioned at 5 μm thickness. The sound speed and the attenuation constant along the articular surface of the tendon from the insertion site to the musculotendinous junction were measured by SAM. The two-dimensional distribution of the acoustic properties was displayed with color-coded scales and was compared to the histologic structure. Toluidine-blue staining and immunohistochemical staining against type II collagen were performed to determine the presence of fibrocartilage besides a standard Elastica-Masson staining to assess the overall histologic structure. The distribution of the sound speed and the attenuation constant showed an almost identical pattern. Both parameters were lower in the non-mineralized fibrocartilage than those in the tendon proper. The area indicating low sound speed corresponded well to the area of metachromasia and type II collagen. The non-mineralized fibrocartilage indicated softer material properties than the tendon proper, which could be interpreted as an adaptation for the various biomechanical stresses at the insertion site. © World Scientific Publishing Company.
Ultrasonic sound speed microscope for biological tissue characterization driven by nanosecond pulse Peer-reviewed

N Hozumi, R Yamashita, CK Lee, M Nagano, K Kobayashi, Y Saijo, M Tanaka, N Tanaka, S Ohtsuki

ACOUSTICAL IMAGING, VOL 27　27　495-501　2004
Publisher: SPRINGER
ISSN：0270-5117
An adaptive fuzzy segmentation of intravascular ultrasound images Peer-reviewed

E dos Santos, M Yoshizawa, A Tanaka, Y Saijo, T Iwamoto, T Yanibe, SI Nitta

2004 2ND IEEE INTERNATIONAL SYMPOSIUM ON BIOMEDICAL IMAGING: MACRO TO NANO, VOLS 1 and 2　1311-1314　2004
Publisher: IEEE

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A system for automatic definition of region of interest (ROI) in intravascular ultrasound images is proposed. This system performs this task in two phases: first a preprocessing based on morphological smoothing and fuzzy enhancement is done and then a fuzzy clustering algorithm is applied to the pre-processed image. The preliminary results showed that this technique is a feasible method for finding calcified regions that can be explored by clas-sifiers.
Morphological-fuzzy filter for enhancement of intravascular ultrasound images Peer-reviewed

E dos Santos, M Yoshizawa, T Iwamoto, A Tanaka, Y Saijo

SICE 2004 ANNUAL CONFERENCE, VOLS 1-3　1394-1397　2004
Publisher: SOC INSTRUMENT CONTROL ENGINEERS JAPAN

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A filter for enhancement of intravascular ultrasound images is proposed. This filter performs this task in two phases: first a pre-processing based on morphological smoothing and then a fuzzy enhancement is done on the basis of the intensity and variance information of the input image. Results have shown that this technique is useful to facilitate the processes of segmentation of regions of interest in intravascular ultrasound images.
Ultrasonic Sound Speed Microscope for Biological Tissue Characterization Driven by Nanosecond Pulse Peer-reviewed

N. Hozumi, R. Yamashita, C-K. Lee, M. Nagao, K. Kobayashi, Y. Saijo, M. Tanaka, N. Tanaka, S. Ohtsuki

Acoustical Science and Technology,　24　(6)　386-390　2003/11
Publisher: Acoustical Society of Japan
DOI： 10.1250/ast.24.386 　

ISSN：1346-3969
Reproduction of Real Blood Flow in Aorta with Ultrasonic-Measurement-Integrated Simulation

Kenichi Funamoto, Toshiyuki Hayase, Atsushi Shirai, Tomoyuki Yambe, Yoshifumi Saijo

Proceedings of the 3rd International Symposium on Advanced Fluid Information (AFI-2003)　39-40　2003/11
Artificial myocardium with an artificial baroreflex system using nano technology Peer-reviewed

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

BIOMEDICINE & PHARMACOTHERAPY　57　122S-125S　2003/10
Publisher: ELSEVIER FRANCE-EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER
DOI： 10.1016/j.biopha.2003.08.016 　

ISSN：0753-3322

eISSN：1950-6007

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

TANAKA N, KOBAYASHI K, HOZUMI N, SAIJO Y, TANAKA M, OHTSUKI S

日本音響学会研究発表会講演論文集　2003　(2)　1161-1162　2003/09/17

ISSN：1340-3168
人工心筋駆動時の心拍ゆらぎ解析に基づき生体の自律神経への影響 Peer-reviewed

段旭東, 白石泰之, 王慶田, 山家智之, 仁田新一, 田中明, 吉澤誠, 柴田宗一, 西條芳文, 小川大介

人工臓器　32　(2)　S149-S149　2003/09
機械式人工心筋の開発心補助効果と生体心臓との力学的相互作用の基礎検討 Peer-reviewed

白石泰之, 岡本英治, 山家智之, 段旭東, 王慶田, 柴田宗一, 田中明, 小川大祐, 吉澤誠, 西條芳文, 仁田新一, 青木秀宜, 永利潤, 川合潤子, 末弘淳一, 吉田敬, 梅津光生, 井口篤志, 田林晄一, 圓山重直, 早瀬敏幸

人工臓器　32　(2)　S149-S149　2003/09
Influence of tissue preparation on the acoustic properties of tissue sections at high frequencies Peer-reviewed

H Sasaki, Y Saijo, M Tanaka, SI Nitta

ULTRASOUND IN MEDICINE AND BIOLOGY　29　(9)　1367-1372　2003/09
Publisher: ELSEVIER SCIENCE INC
DOI： 10.1016/S0301-5629(03)00991-8 　

ISSN：0301-5629

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The purpose of the present study was to clarify the influence of tissue preparation on the high-frequency acoustic properties by comparing the acoustic properties of the formalin-fixed, paraffin-embedded, deparaffinized sections and formalin-fixed, frozen sections for two types of fat-containing renal cancer and fat-free renal oncocytoma using a SAM. There was no significant difference for the sound speed among the clear cell, granular cell renal cancer and oncocytoma in either groups, but the attenuation constant was significantly higher for the frozen than for that of the paraffin section in fat-containing renal cancer. In fat-free oncocytoma, there was no significant difference for the attenuation constant in either group. The data suggest that the fat component, which had been eluted by paraffinization, is stored and the true acoustic properties of the tissue can be measured in frozen section. (C) 2003 World Federation for Ultrasound in Medicine Biology.
Fast Fourier transform acoustic microscopy for biological tissues. Peer-reviewed

Saijo Y, Hozumi N, Kobayashi K, Lee C, Nagao M, Ohtsuki S, Tanaka N, Sasaki H, Tanaka M

Ultrasound Med Biol　29　(5S)　S20　2003/04
Pocket-size echo connectable to a personal computer. Peer-reviewed

Saijo Y, Kobayashi K, Arai H, Nemoto Y, Nitta S

Ultrasound Med Biol　29　(5S)　S54　2003/04
Intravascular tissue velocity imaging of coronary artery. Peer-reviewed

Saijo Y, Tanaka A, Owada N, Akino Y, Nitta S

Ultrasound Med Biol　29　(5S)　S173　2003/04
超音波音速顕微鏡のための試料存在判定法の検討

田中直彦, 小林和人, 穂積直裕, 西条芳文, 田中元直, 大槻茂雄

日本音響学会研究発表会講演論文集　2003　1345-1346　2003/03/18

ISSN：1340-3168
医療用フーリエ変換型超音波顕微鏡の線形性に関する研究

LEE C, 山下理都子, 村本裕二, 穂積直裕, 長尾雅行, 小林和人, 西条芳文

電気学会全国大会講演論文集　2003　(1)　263　2003/03/17
Toward a neuro-fuzzy system for automatic segmentation and characterization of intravascular ultrasound images Peer-reviewed

E dos Santos, M Yoshizawa, A Tanaka, Y Saijo, T Yambe, S Nitta

SICE 2003 ANNUAL CONFERENCE, VOLS 1-3　1586-1589　2003
Publisher: IEEE

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A project of a neuro-fuzzy system for automatic segmentation and characterization of intravascular ultrasound images is presented. The segmentation is performed by the use of the Fuzzy C Means algorithm and characterization is performed by using a neuro-fuzzy system capable of learning from images manually segmented and labeled by medical doctors. The proposed system has just been developed, and, in the actual stage, preliminary tests with the Inter Class Contrast validity measure have presented encouraging results.
Evidence-based Simulation of Blood Flow with Feedback of Ultrasonic Measurement

Toshiyuki Hayase, Kenichi Funamoto, Atsushi Shirai, Tomoyuki Yambe, Yoshifumi Saijo

The 1st International Symposium on Future Medical Engineering based on Bio-nanotechnology　40-42　2003/01
Recent progress in artificial organ research at Tohoku University Peer-reviewed

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

ARTIFICIAL ORGANS　27　(1)　2-7　2003/01
Publisher: BLACKWELL PUBLISHING INC
DOI： 10.1046/j.1525-1594.2003.07181.x 　

ISSN：0160-564X

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

Toshiyuki Hayase, Kenichi Funamoto, Keisuke Nisugi, Atsushi Shirai, Tomoyuki Yambe, Yoshifumi Saijo

Proceedings of Mini-Symposium on Advanced Fluid Information: Fusion of EFD and CFD　77-85　2002/12
Proximal (entry) tear of dissecting aortic aneurysm visualized by three-dimensional echocardiography Peer-reviewed

Y Saijo, H Akimoto, Y Saiki, K Tabayashi, T Horinouchi, T Kobayashi, S Nitta

JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY　124　(6)　1245-1246　2002/12
Publisher: MOSBY, INC
DOI： 10.1067/mtc.2002.125639 　

ISSN：0022-5223
ナノ秒パルス励起による生体組織用超音波音速顕微鏡

穂積直裕, 山下理都子, 長尾雅行, 小林和人, 西条芳文, 田中元直, 田中直彦, 大槻茂雄

日本音響学会研究発表会講演論文集　2002　1007-1008　2002/09/26

ISSN：1340-3168
生体組織用超音波顕微鏡のための音速分布推定法の検討

田中直彦, 小林和人, 穂積直裕, 西条芳文, 田中元直, 大槻茂雄

日本音響学会研究発表会講演論文集　2002　1011-1012　2002/09/26

ISSN：1340-3168
パルス励起超音波音速顕微鏡のビーム形状の検討

小林和人, 根本由記子, 穂積直裕, 西条芳文, 田中元直, 田中直彦, 大槻茂雄

日本音響学会研究発表会講演論文集　2002　1009-1010　2002/09/26

ISSN：1340-3168
Acoustic inhomogeneity of carotid arterial plaques determined by GHz frequency range acoustic microscopy Peer-reviewed

Y Saijo, CS Jorgensen, P Mondek, Sefranek, V, W Paaske

ULTRASOUND IN MEDICINE AND BIOLOGY　28　(7)　933-937　2002/07
Publisher: ELSEVIER SCIENCE INC
DOI： 10.1016/S0301-5629(02)00527-6 　

ISSN：0301-5629

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Characterization of the structure and composition of carotid arterial plaques is important to predict the risk of embolic and thrombotic events. In clinical echography, echolucent lesions seem to be more associated with stroke than echogenic lesions, and a low grey-scale median is associated with a fivefold increase in the incidence of silent infarcts. In the present study, five fixed human carotid atherosclerotic lesions were observed by GHz-range scanning acoustic microscopy (SAM). The atherosclerotic lesions were characterized by either thickened fibrosis with dense collagen fibers or lipid accumulation with sparse collagen network by optical microscopy. SAM revealed that the fibrosis was classified into type I and III collagen by attenuation of ultrasound (US) and that the sound field of lipid accumulation lesions became inhomogeneous. The results would provide the scientific basis for the images of vulnerable plaques being produced in diagnostic US. (E-mail: saijo@idac. tohoku.ac.jp) (C) 2002 World Federation for Ultrasound in Medicine Biology.
Detecting Cardiac Allograft Rejection by Acoustic Microscopy Peer-reviewed

Y. Saijo, A. Iguchi, K. Tabayashi, K. Kobayashi, H. Sasaki, A. Tanaka, N. Hozumi, S. Nitta

Acoustical Imaging,　26　105-110　2002
Application of scanning acoustic microscopy for assessing stress distribution in atherosclerotic plaque Peer-reviewed

Y Saijo, T Ohashi, H Sasaki, M Sato, CS Jorgensen, SI Nitta

ANNALS OF BIOMEDICAL ENGINEERING　29　(12)　1048-1053　2001/12
Publisher: BIOMEDICAL ENGINEERING SOC AMER INST PHYSICS
DOI： 10.1114/1.1424912 　

ISSN：0090-6964

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Scanning acoustic microscopy (SAM) was equipped to assess the acoustic properties of normal and atherosclerotic coronary arteries. The SAM image in the atherosclerotic lesion clearly demonstrated that the sound speed was higher than that in the normal intima, and that the variation of elasticity was found within the fibrous cap of the plaque. Young's elastic modulus of each region was calculated and the finite element analysis was applied to derive the stress distribution in these arterial walls. In a case of normal coronary artery, the stress was dominant in the intima and the distribution was rather homogeneous and in a case of atherosclerosis, high stress was concentrated to the relatively soft lesion in the fibrous cap overlying lipid pool. SAM provides information on the physical properties, which cannot be obtained by the optical microscope. The results would help in understanding the pathological features of atherosclerosis. (C) 2001 Biomedical Engineering Society.
Ultrasonic tissue characterization of collagen in lipid-rich plaques in apoE-deficient mice Peer-reviewed

Y Saijo, CS Jorgensen, E Falk

ATHEROSCLEROSIS　158　(2)　289-295　2001/10
Publisher: ELSEVIER SCI IRELAND LTD
DOI： 10.1016/S0021-9150(01)00435-X 　

ISSN：0021-9150

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Mechanical failure of the fibrous cap of a vulnerable atherosclerotic plaque may lead to sudden plaque rupture and thus precipitate arterial thrombosis. Because ultrasound correlates strongly with mechanical features of tissues it might provide information on the stability of fibrous caps. The acoustic properties of the normal vessel wall and plaques, particularly fibrous caps of lipid-rich plaques, were evaluated in the aortic roots of six normal C57BL mice and 12 atherosclerosis-prone apoE-deficient (apoE(-/-)) mice by scanning acoustic microscopy (SAM). After processing, the attenuation of high-frequency (1.1 GHz) focused ultrasound was measured in unstained tissue sections by SAM followed by quantification of the amount and type of collagen in picrosirius red stained sections by means of polarized light microscopy (PLM). The acoustic and optical images were superimposed and ultrasonic attenuation was measured in different tissue components. Pertinent plaque features, particularly fibrous caps covering lipid-rich pools, were clearly visualized by both SAM and PLM. Collagen appeared green in thin fibrous caps and bright orange in thick caps by PLM. The attenuation of ultrasound was significantly higher in the collagen fibers with orange color compared to those with green color (17.2 versus 6.6 x 10(3) dB/min). SAM has shown the possibility to characterize the types of collagen by high frequency intravascular ultrasound in vivo and it might improve our understanding of the vulnerable plaque and its sudden rupture from micro-mechanical point of view. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.
Evaluation of the biomechanics of atherosclerosis by acoustic microscopy Peer-reviewed

Yoshifumi Saijo, Shin-ichi Nitta, Claus S. Jørgensen, Erling Falk

Proceedings of SPIE - The International Society for Optical Engineering　4335　(1)　228-235　2001/07/24

DOI： 10.1117/12.434177 　

ISSN：0277-786X

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Acoustic microscopy provides not only the morphology, but also the biomechanical properties of the biological soft tissues. The biomechanics of atherosclerosis is important because the pathophysiology of atherosclerosis is closely related with mechanical properties and mechanical stress. Rupture of the fibrous cap of atheromatous plaque is the initial event in acute coronary syndrome such as acute myocardial infarction or unstable angina. In addition to extrinsic physical stresses to the plaque, the intrinsic biomechanical property of the plaque is important for assessing the mechanism of the rupture. Two sets of SAMs operating in 100 to 200 MHz and in 800 MHz to 1.3 GHz were equipped to measure the acoustic properties of atherosclerosis of human or mouse arteries. The values of attenuation and sound speed in the tissue components of atherosclerosis were measured by analyzing the frequency dependent characteristics of the amplitude and phase signals. Both values were highest in calcification and lowest in lipid pool. Although attenuation and sound speed were relatively high in intimal fibrosis, the inhomogeneity of acoustic parameters was found within the fibrous cap. Polarized microscopy for the collagen stained with Picrosirius red showed that the attenuation of ultrasound was significantly higher in type I collagen with orange polarized color compared to type III collagen with green color. SAM has shown the possibility to detect the plaque vulnerability and it might improve our understanding of the sudden rupture from micro-mechanical point of view. © 2001 SPIE.
A single-beat estimation method for Emax directly based on linearity of ventricular elastance Peer-reviewed

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

PROCEEDINGS OF THE 23RD ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY, VOLS 1-4　23　155-155　2001
Publisher: IEEE
ISSN：1094-687X
Microscopy Peer-reviewed

Yoshifumi Saijo, Noriyoshi Chubachi

Ultrasound in Medicine and Biology　26　(1)　S30-S32　2000/05
Publisher: Elsevier Science Ltd
DOI： 10.1016/S0301-5629(00)00157-5 　

ISSN：0301-5629

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In 1973, Stanford University has developed a scanning acoustic microscope (SAM) for use in the biomedical field. The technique became widely applied because of its high resolution and high quality imaging.
Collagen characterization by polarized and acoustic microscopy. Peer-reviewed

Saijo Y, Sasaki H, Nitta S, Tanaka M, Jorgensen CS, Falk E

Ultrasound Med Biol　26　(Suppl 2)　A57　2000/04
Prediction of plaque rupture by finite element analysis of IVUS imaging. Peer-reviewed

Saijo Y, Ohashi T, Sasaki H, Kanno T, Miyakawa T, Nitta S, Tanaka M

Ultrasound Med Biol　26　(Suppl 2)　A88　2000/04
Visualization of human umbilical vein endothelial cells by acoustic microscopy Peer-reviewed

Y Saijo, H Sasaki, M Sato, S Nitta, M Tanaka

ULTRASONICS　38　(1-8)　396-399　2000/03
Publisher: ELSEVIER SCIENCE BV
DOI： 10.1016/S0041-624X(99)00200-0 　

ISSN：0041-624X

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The morphology and acoustic properties of the human umbilical vein endothelial cells (HUVECs) were evaluated using a scanning acoustic microscope system. HUVECs were cultured for 4 days and exposed to the endotoxin for 4 h. The frequency of the scanning acoustic microscope was variable between 100 and 210 MHz. By changing the measuring frequency, ultrasonic amplitude and phase were measured and the quantitative value of attenuation was calculated. Before and after endotoxin stimuli, HUVECs were observed by scanning acoustic microscopy and the attenuation was measured. The acoustic images were successfully obtained to identify the outer shape of the HUVEC and the location of the nucleus in the cell. The attenuation of the nucleus is higher than that of the cytoplasm. The attenuation of the cytoplasm was increased and became inhomogeneous after endotoxin exposure. This finding would be related to the change of F-actin filaments, which is the main component of the cytoskeleton. Scanning acoustic microscopy is useful for assessing the cellular viscoelastic properties since it can detect both the morphological and acoustic changes without contacting the cellular surface. (C) 2000 Elsevier Science B.V. All rights reserved.
Evaluation of the inner-surface morphology of an artificial heart by acoustic microscopy Peer-reviewed

Y Saijo, H Okawai, H Sasaki, T Yambe, S Nitta, M Tanaka, K Kobayashi, Y Honda

ARTIFICIAL ORGANS　24　(1)　64-69　2000/01
Publisher: BLACKWELL SCIENCE INC
DOI： 10.1046/j.1525-1594.2000.06349.x 　

ISSN：0160-564X

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The total artificial heart (TAH) is being developed for permanent replacement of the natural heart instead of heart transplantation. The need for detecting the material fatigue in the TAH is increasing in order to guarantee long-term use. In this study, the inner surface morphology of the TAH was evaluated by a specially developed scanning acoustic microscope (SAM) system operating in the frequency range of 100-200 MHz. The inner sac of our TAH consisted of polyvinylchloride coated with polyurethane, and the SAM investigations were performed before and after the implantations in goats. The amplitude images of the SAM demonstrated protein adhesion on the inner surface of the TAH after the animal experiment, and the phase images showed distortion of the wall with spatial resolution of 0.2 mu m. These results suggest the feasibility of a high-frequency ultrasound for evaluating the material fatigue of TAH.
Collagen characterization of fibrous caps in Apo-E deficient mice by acoustic microscopy. Peer-reviewed

Saijo Y, Jorgensen C, Falk E, Nitta S

Circulation　100　(18)　I251　1999/04
Successful closure of coronary-bronchial artery fistula with vein graft-coated stent Peer-reviewed

Y Saijo, K Izutsu, T Sonobe, Y Okuyama, T Yambe, S Nitta

CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS　46　(2)　214-217　1999/02
Publisher: WILEY-LISS
DOI： 10.1002/(SICI)1522-726X(199902)46:2<214::AID-CCD22>3.0.CO;2-J 　

ISSN：1522-1946

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A coronary-bronchial fistula and aneurysmal dilatation of the proximal part of the fistula was successfully closed using an autologous Vein graft-coated stent (Palmaz-Schatz stent). This is the first report that demonstrates the feasibility of the vein-coated stent for the treatment of congenital disease. (C) 1999 Wiley-Liss, Inc.
Bilateral pneumothoraces with multiple bullae in a patient with asymptomatic bronchiolitis obliterans 10 years after bone marrow transplantation Peer-reviewed

T. Suzuki, Y. Saijo, M. Ebina, M. Yaekashiwa, M. Minegishi, S. Tsuchiya, T. Konno, S. Ono, Y. Matsumura, S. Fujimura, T. Nukiwa

Bone Marrow Transplantation　23　(8)　829-831　1999
Publisher: Nature Publishing Group
DOI： 10.1038/sj.bmt.1701660 　

ISSN：0268-3369

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A 16-year-old boy developed bronchiolitis obliterans (BO) 10 years after BMT for myelodysplastic syndrome. Although the patient complained of almost no dyspnea on exertion, he had mild hypercapnea with a markedly reduced forced expiratory volume of 0.32 l. Chest X-rays showed occasional bilateral minimal pneumothoraces, which is in accordance with the existence of multiple small bullae found on the pleural surface at video-assisted thoracic surgery. Histologic examination of the biopsied lung revealed BO. This case indicates that BO in adolescence following BMT and possible chronic GVHD may be masked because of lung immaturity at BMT, and BO after BMT may be associated with multiple pleural bullae.
Acoustic properties of atherosclerosis of human aorta obtained with high-frequency ultrasound Peer-reviewed

Y Saijo, H Sasaki, H Okawai, S Nitta, M Tanaka

ULTRASOUND IN MEDICINE AND BIOLOGY　24　(7)　1061-1064　1998/09
Publisher: PERGAMON-ELSEVIER SCIENCE LTD
DOI： 10.1016/S0301-5629(98)00054-4 　

ISSN：0301-5629

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The ultrasonic properties of the tissue elements in the aorta were measured using a scanning acoustic microscope (SAM), Twelve autopsied aortas were formalin-fixed, frozen and sectioned at 10 mu m thickness and mounted on glass slides for SAM investigation. A specially developed SAM system operating in the frequency range of 100-200 MHz was employed, and color-coded images of the two-dimensional (2-D) distributions of attenuation and sound speed were displayed. The region-of-interest (ROI) for attenuation and sound speed measurements was determined by comparison of optical and acoustic images. The average value of the slope of attenuation was 0.61 dB/mm/MHz and the sound speed was 1568 m/s in the normal intima; 2.5 dB/mm/MHz, 1760 m/s in the calcificated lesion; 1.7 dB/mm/MHz and 1677 m/s in the fibrosis; and 0.34 dB/mm/MHz, 1526 m/s in the fatty material, respectively. Acoustic microscopy provides the basic data for understanding the IVUS imaging of atherosclerosis, as well as on the pathological features of atherosclerosis, (C) 1998 World Federation for Ultrasound in Medicine & Biology.
Brain imaging by acoustic microscopy. Peer-reviewed

Saijo Yoshifumi, Sasaki Hidehiko, Sato Kozo, Okawai Hiroaki, Nitta Shin-ichi, Tanaka Motonao

Eur J Ultrasound　7　(suppl)　s55　1998/04
Non-destructive Detection of Material Fatigue in Artificial Heart by Scanning Acoustic Microscopy

SAIJO Yoshifumi, OKAWAI Hiroaki, SASAKI Hidehiko, YAMBE Tomoyuki, NITTA Shin-ichi, TANAKA Motonao, KOBAYASHI Kazuto, HONDA Yosuke

Transactions of Visualization Society of Japan　18　(70)　187-191_1　1998
Publisher: The Visualization Society of Japan
DOI： 10.3154/jvs.18.70_187 　

ISSN：0916-4731
Morphological and acoustical changes of endothelium by fluid shear stress Peer-reviewed

Y Saijo, H Sasaki, N Kataoka, M Sato, S Nitta, M Tanaka

1998 IEEE ULTRASONICS SYMPOSIUM - PROCEEDINGS, VOLS 1 AND 2　2　1333-1336　1998
Publisher: IEEE
ISSN：1051-0117

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Fluid shear stress was applied on the cultured endothelial cells by a continuous flow pump. After 24 hrs of flow stress, the morphological changes and acoustic properties were determined by a specially developed acoustic microscope system with a frequency range between 100 and 210 MHz. The shape of the cells was elongated along a flow direction, and the sound speed of the cytoplasm showed an increasing trend. Acoustic microscopy should be a useful tool for examining the biomechanics of the cells, because it can provide both the morphological and physical properties of the cells in a short time.
Latest microscopic technique. From principle to application. Form evaluation of cultured cells by ultrasonic microscopes.

SAIJO Y, OKAWAI H, NITTA S, TANAKA M

Transactions of Japanese Society for Medical and Biological Engineering　11　(10)　37-41　1997/10/10
Publisher: Japanese Society for Medical and Biological Engineering
DOI： 10.11239/jsmbe1987.11.10_37 　

ISSN：0913-7556
Acoustic properties of dialysed kidney by scanning acoustic microscopy Peer-reviewed

H Sasaki, Y Saijo, M Tanaka, S Nitta, Y Terasawa, T Yambe, Y Taguma

NEPHROLOGY DIALYSIS TRANSPLANTATION　12　(10)　2151-2154　1997/10
Publisher: OXFORD UNIV PRESS
DOI： 10.1093/ndt/12.10.2151 　

ISSN：0931-0509

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Background, A correlation between acquired renal cysts in the dialysed kidney and renal cancer has long been debated, but no changes in the physical properties of kidneys at the microscopic level have been reported. The purpose of the present study was to classify the physical properties of the kidneys of patients undergoing haemodialysis at several stages of pathology by use of the scanning acoustic microscope. Methods, Sixteen surgically excised kidneys of dialysis patients were investigated. Tissues were fixed in 10% formalin, frozen in acetone, and cut 10 mu m thick on a cryostat. We used a scanning acoustic microscope operated in the frequency range of 100-200 MHz. Attenuation constant and sound speed were measured on a two-dimensional distribution. Results, The attenuation constant for inflammatory granulation tissue was significantly higher than that for hyaline degeneration tissue (P<0.001). Sound speed was high for granulation tissue, but tended to diminish gradually for hyaline degeneration. Sound speed increased again with progression to cystic degeneration (P<0.001), but the attenuation constant remained low. When a cystic kidney contained a malignant lesion, the previously low attenuation constant rose at that site (P<0.001), and the previously high sound speed was diminished (P<0.001). Conclusion, Our data suggest that the physical properties of dialysed kidneys at different stages of pathology can be classified by their acoustic properties. Simultaneous evaluation of attenuation constant and sound speed is considered applicable to determining whether tissues contain malignant elements.
Characterization of renal angiomyolipoma by scanning acoustic microscopy Peer-reviewed

H Sasaki, Y Saijo, M Tanaka, S Nitta, T Yambe, Y Terasawa

JOURNAL OF PATHOLOGY　181　(4)　455-461　1997/04
Publisher: JOHN WILEY & SONS LTD
DOI： 10.1002/(SICI)1096-9896(199704)181:4<455::AID-PATH788>3.0.CO;2-J 　

ISSN：0022-3417

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A scanning acoustic microscope system was used to differentiate renal angiomyolipoma from renal cell carcinoma, The ultrasonic frequency used ranged from 100 to 200 MHz, and the attenuation constant and sound speed were measured on a two-dimensional distribution. The sound speed was significantly lower for lipoma cells than for vessels, smooth muscle fibres, clear cell renal cancer or granular cell renal cancer, The attenuation constant was significantly lower for lipoma cells than for vessels or clear cells, Both acoustic parameters for smooth muscle fibres were significantly lower than for vessels, The heterogeneity of the microacoustic field in renal angiomyolipoma is closely related to the high intensity echo observed on clinical echography, Renal angiomyolipoma and renal cell carcinoma can thus be distinguished by acoustic examination. (C) 1997 by John Wiley & Sons, Ltd.
Visualization of cultured cells by scanning acoustic microscope system. Peer-reviewed

Saijo Yoshifumi, Sasaki Hidehiko, Okawai Hiroaki, Nitta Shin-ichi, Tanaka Motonao

Proc 1997 World Congress on Ultrasonics　1　502-503　1997/04
Effect of argatroban for the treatment of intimal dissection following percutaneous transluminal coronary angioplasty. Peer-reviewed

Saijo Y, Kikuchi Y, Izutsu K, Yambe T, Nitta S

1st International Congress on Coronary Artery Disease　1　44　1997/04
Anatomical and physiological approach to the chromatic mechanisms

SAIJO Yoshifumi

Transactions of Visualization Society of Japan　17　(64)　7-11　1997/01/05
Publisher: The Visualization Society of Japan
DOI： 10.3154/jvs.17.7 　

ISSN：0916-4731
Relationship between micro- and macro-acoustic properties of myocardium Peer-reviewed

Y Saijo, H Sasaki, H Okawai, S Nitta

PROCEEDINGS OF THE 18TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY, VOL 18, PTS 1-5　18　863-864　1997
Publisher: IEEE

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The objective of the present study is to assess the relationship between micro-and macro-acoustic properties of myocardium. The values of ultrasonic attenuation and sound speed of the myocardium at 3.5 MHz were obtained by frequency domain analysis of the pulse response in order to determine the macro-acoustic properties. The micro-acoustic properties were obtained by a specially developed scanning acoustic microscope system operating in the frequency range of 100-200 MHz. At 3.5 MHz, the sound speed was 1600 m/s and the attenuation was 2.5 dB/cm in the normal myocardium, 1582 m/s and 5.8 dB/cm in the necrosis, respectively. At 130 MHz, both values were 1614 m/s and 1.1 dB/mm/MHz in the normal myocardium, 1578 m/s and 0.6 dB/mm/MHz in the necrosis, respectively. The results suggest that the ultrasonic attenuation is affected by both the chemical components and the structure of the tissue.
Ultrasonic tissue characterization of infarcted myocardium by scanning acoustic microscopy Peer-reviewed

Y Saijo, M Tanaka, H Okawai, H Sasaki, SI Nitta, F Dunn

ULTRASOUND IN MEDICINE AND BIOLOGY　23　(1)　77-85　1997
Publisher: PERGAMON-ELSEVIER SCIENCE LTD
DOI： 10.1016/S0301-5629(96)00174-3 　

ISSN：0301-5629

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The purpose of this study was to ultrasonically characterize infarcted human myocardial tissue at the microscopic level by scanning acoustic microscopy. Infarcted myocardial specimens from ten cases with acute myocardial infarction were studied. Specimens were formalin fixed, paraffin embedded and sectioned to 10-mu m thickness. A specially developed scanning acoustic microscope system, operating in the 100- to 200-MHz ultrasound frequency range, was used for the measurements. The values of the attenuation constant were 0.94+/-0.04 dB/mm/MHz in normal myocardium, 0.71+/-0.12 dB/mm/MHz in degenerated myocardium, 0.88+/-0.47 dB/mm/MHz in granulation tissue and 1.75+/-0.11 dB/mmm/lHz in fibrosis. The values of sound speed were 1620.2+/-8.2 m/s in normal myocardium, 1572.4+/-10.6 m/s in degenerated myocardium, 1590.2+/-32.5 m/s in granulation tissue and 1690.3+/-9.1 m/s in fibrosis. The ultrasonic properties of the diseased myocardium at the microscopic level will provide important information for ultrasonic tissue characterization at the macroscopic level. Copyright (C) 1997 World Federation for Ultrasound in Medicine & Biology.
Ultrasonic properties of myocardium in low MHz frequencies assessed by acoustic microscopy. Peer-reviewed

Saijo Yoshifumi, Sasaki Hidehiko, Okawai Hiroaki, Nitta Shin-ichi

Eur J Ultrasound　4　(suppl 1)　s64　1996/04
Visualization of inner surface morphology of artificial heart by scanning acoustic microscopy. Peer-reviewed

Saijo Yoshifumi, Sasaki Hidehiko, Okawai Hiroaki, Yambe Tomoyuki, Nitta Shin-ichi

Proc 2nd International Congress on Robotics, Vision, Parallel Processing for Industrial Automation　2　51-54　1996/04
Evaluation of the material fatigue of artificial heart by a frequency domain analysis of pulsed ultrasound. Peer-reviewed

Saijo Yoshifumi, Sasaki Hidehiko, Okawai Hiroaki, Yambe Tomoyuki, Nitta Shin-ichi

Proc 2nd International Congress on Robotics, Vision, Parallel Processing for Industrial Automation　2　108-111　1996/04
Influence of tissue preparation on the high-frequency acoustic properties of normal kidney tissue Peer-reviewed

H Sasaki, Y Saijo, M Tanaka, H Okawai, Y Terasawa, T Yambe, S Nitta

ULTRASOUND IN MEDICINE AND BIOLOGY　22　(9)　1261-1265　1996
Publisher: PERGAMON-ELSEVIER SCIENCE LTD
DOI： 10.1016/S0301-5629(96)00150-0 　

ISSN：0301-5629

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The influence of various tissue preparations on the acoustic properties of normal kidney tissue at high frequencies was investigated. Eight surgically excised normal kidney tissue specimens were classified into three groups: (i) fresh, frozen section, (ii) formalin-fixed, frozen section and (iii) formalin-fixed, paraffin section. Scanning acoustic microscopy operating in the frequency range of 100-200 MHz was used to display the two-dimensional distribution of attenuation constant and sound speed. Our results indicate that (i) there is no significant variation in both acoustic parameters between the three tissue groups, (ii) fixation by 10% formalin produces no significant change in the acoustic parameters, (iii) in fat-free tissue regions, the acoustic parameters are independent of preparation method and (iv) frozen sections must be used to assess the acoustic parameters in fat-rich tissues. Copyright (C) 1996 World Federation for Ultrasound in Medicine & Biology.
Ultrasonic tissue characterization of renal cell carcinoma tissue Peer-reviewed

Hidehiko Sasaki, Motonao Tanaka, Yoshifumi Saijo, Hiroaki Okawai, Yoshio Terasawa, Shin-Ichi Nitta, Kiichi Suzuki

Nephron　74　(1)　125-130　1996

DOI： 10.1159/000189291 　

ISSN：2235-3186 1660-8151

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The purpose of this study was to characterize renal cell carcinoma tissue by the measurement of microacoustic properties. A scanning acoustic microscope system operating in the frequency range of 100-200 MHz was employed and the attenuation constant and sound speed were measured on the two-dimensional distribution. The values of attenuation constant and sound speed were lower in both kinds of cancer cells than those in normal kidney, although a significant difference was not found between the clear cell and granular cell. Also, both acoustic parameters of cancer cells were significantly lower than those in hemorrhage and fibrosis. These data suggest that the elasticity of renal cell carcinoma tissue may be lower than that of normal kidney. Moreover, the high intensity echo in clinical echography may be related to the heterogeneity of the microacoustic field in the carcinoma tissue. © 1996 S. Karger AG, Basel.
Ultrasonic tissue characterization of three-layered structure of coronary artery by scanning acoustic microscopy. Peer-reviewed

Saijo Yoshifumi, Sasaki Hidehiko, Naganuma Toru, Tanaka Motonao

J Heart Failure　2　558　1995/04
Visualization of intracardiac local flow states by two-dimensional stream line distributions. Peer-reviewed

Saijo Yoshifumi, Tanaka Motonao, Takahashi Kazuhiko, Chiba Shigeki, Mitsuoka Mikio, Naganuma Toru

J Heart Failure　2　622　1995/04
Ultrasonic properties of the tissue elements of coronary artery by scanning acoustic microscopy. Peer-reviewed

Saijo Yoshifumi, Sasaki Hidehiko, Naganuma Toru, Tanaka Motonao

Heart Vessels　suppl 11　44　1995/04
Estimation of local blood flow volume by stream line distributions. Peer-reviewed

Saijo Yoshifumi, Tanaka Motonao, Takahashi Kazuhiko, Chiba Shigeki, Mitsuoka Mikio, Naganuma Toru

Heart Vessels　suppl 11　81　1995/04
Frequency dependent characteristics of ultrasonic attenuation in liver tissue. Peer-reviewed

Saijo Yoshifumi, Sasaki Hidehiko, Okawai Hiroaki, Tanaka Motonao

Proc 1st World Congress on Ultrasonics　1　1059-1062　1995/04
Ultrasonic tissue characterization of diseased myocardium by scanning acoustic microscopy Peer-reviewed

Y. Saijo, H. Sasaki, T. Naganuma, M. Tanaka

Journal of Cardiology　25　(3)　127-132　1995

ISSN：0914-5087

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Ultrasonic tissue characterization of the myocardium has become very important because the requirement for evaluating local cardiac function has increased. In the present study, the acoustic properties of the tissue elements in myocardial infarction were measured by a specially developed scanning acoustic microscope (SAM) system, and the echo intensity of the infarcted myocardium was assessed. Ten samples of infarcted myocardium obtained at autopsy were formalin-fixed, paraffin-embedded and cut into 10 μm thick slices. The SAM system was operated in the frequency range of 100 to 200 MHz. The values of the attenuation constant and sound speed were measured in five tissue elements, normal myocardium, degenerated myocardium, fibrosis, granulation, and hemorrhage by comparing the optical microscopic image and acoustic images. The density of each tissue element was measured by the CuSO4 method, and the specific acoustic impedance was calculated by multiplying the sound speed and the density of each tissue element. The specific acoustic impedance was 1.75 x 106 Ns/m3 in normal myocardium, 1.69 x 106 Ns/m3 in degenerated myocardium, and 1.85 x 106 Ns/m3 in fibrosis. The intensity of the reflected ultrasound at the interface between two different tissue elements was calculated by the difference of specific acoustic impedance. Using the sensitivity changing method in clinical echocardiography, the intensity of myocardial scar was -15 dB compared to the pericardial echo. The corrected ideal ultrasonic reflection between degenerated myocardium and fibrosis was calculated as -15.4 dB. The results suggest that measurement of acoustic properties is very important to provide basic data for ultrasonic characterization of myocardium tissue.
「脈診」における決定論的カオス Peer-reviewed

山家智之, 仁田新一, 高橋和彦, 密岡幹夫, 千葉茂樹, 薗部太郎, 西條芳文, 永沼滋, 柿沼義人, 井筒憲司, 永沼徹, 小林信一, 佐々木英彦, 芳賀洋一, 南家俊介, 大沢上, 田中元信, 吉沢誠, 小出訓, 阿部健一, 竹田宏, 高島充, 佐藤由樹, 渥美和彦

自律神経　31　85-91　1994/04
Ultrasonic tissue characterization of coronary artery by scanning acoustic microscope. Peer-reviewed

Saijo Yoshifumi, Sasaki Hidehiko, Okawai Hiroaki, Naganuma Toru, Tanaka Motonao

Ultrasound Med Biol　20　(suppl 1)　72　1994/04
Assessment of three-layered appearance of coronary artery in intravascular ultrasound by scanning acoustic microscope. Peer-reviewed

Saijo Yoshifumi, Sasaki Hidehiko, Naganuma Toru, Tanaka Motonao

Eur Heart J　15　(suppl)　258　1994/04
VISUALIZATION OF ACOUSTIC PROPERTIES OF BIOLOGICAL TISSUES BY SCANNING ACOUSTIC MICROSCOPY

SAIJO Yoshifumi, TANAKA Motonao

Transactions of Visualization Society of Japan　14　(2)　189-192　1994
Publisher: The Visualization Society of Japan
DOI： 10.3154/jvs.14.Supplement2_189 　

ISSN：0916-4731

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It is very important to determine the acoustic properties of biological tissues for two major aspects; one is that the acoustic parameters give the physical properties that could not be detected by optical microscopy, and the other is that the data provides information for understanding echographic imaging.In the present study, a scanning acoustic microscope (SAM) system was equipped to measure the acoustic properties of biological tissue at the microscopic level.
Assessment of elasticity of acute myocardial infarction tissue by a scanning acoustic microscope system. Peer-reviewed

Saijo Yoshifumi, Okawai Hiroaki, Sasaki Hidehiko, Naganuma Toru, Tanaka Motonao

Eur J Ultrasound　1　s64　1993/04
Estimation of intracardiac local flow state by two-dimensional display of the stream lines. Peer-reviewed

Saijo Yoshifumi, Tanaka Motonao, Yamamoto Atsuko, Endo Norio, Takahashi Kazuhiko, Satoh Noriko, Chiba Shigeki

J Cardiol　23　(suppl 37)　125-131　1993/04
Echo-guided transaortic left ventricular myotomy for idiopathic hypertrophic subaortic stenosis. Peer-reviewed

Nitta S, Yambe T, Nitta K, Katahira Y, Saijo Y, Sonobe T, Naganuma S, Kakinuma Y, Tanaka M, Miura M

Sci Rep Res Inst Tohoku Univ [Med]　38　(2-4)　65-67　1991/12
[A case of giant cell myocarditis associated with a progressive disturbance in the conduction system] Peer-reviewed

Saijo Y, Nitta S, Katahira Y, Takahashi K, Yambe T, Endoh N, Sonobe T, Tanaka M, Meguro T, Nitta K

Kokyu To Junkan　39　(4)　373-376　1991/04

DOI： 10.11477/mf.1404900261 　
THE ULTRASONIC PROPERTIES OF GASTRIC-CANCER TISSUES OBTAINED WITH A SCANNING ACOUSTIC MICROSCOPE SYSTEM Peer-reviewed

Y SAIJO, M TANAKA, H OKAWAI, F DUNN

ULTRASOUND IN MEDICINE AND BIOLOGY　17　(7)　709-714　1991
Publisher: PERGAMON-ELSEVIER SCIENCE LTD
ISSN：0301-5629

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A newly developed scanning acoustic microscope (SAM) system operating in the frequency range of 100-200 MHz has been employed to measure the attenuation and the sound speed of formalin-fixed specimens of five different types of gastric cancer. Signet-ring cell carcinoma specimens exhibit attenuation constant and sound speed values significantly lower than other types of gastric cancer tissues. Tubular adenocarcinoma specimens exhibit a trend toward higher attenuation and sound speed values as the cell type become differentiated. Our measurements and observations suggest that the ultrasonic properties are influenced by cellular arrangement, intercellular junction and intracellular chemical components.
Regional myocardial behaviour cardiac surface under arrhythmic conditions

Uematsu M, Shiraishi Y, Sekine K, Yambe T, Saijo Y, Ando H, Park Y, Takeda S, Iwasaki K, Umezu M

Proceedings of 12th International Conference on Biomedical Engineering　12　1A5-05

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Misc. 211

High frequency ultrasound / photoacoustic imaging at Tohoku University

西條芳文, 新楯諒, 鈴木陸, 石井琢郎, 荒川元孝, 梅村晋一郎, 吉澤晋, 長岡亮, 小林和人, 根本隆治

超音波医学 Supplement　49　2022

ISSN：1881-9311
Evaluation of Coherence Factor Weighting Methods for Enhancing the Image Quality of Photoacoustic Microscopy

鈴木陸, 新楯諒, 石井琢郎, 石井琢郎, 西條芳文

超音波医学 Supplement　49　2022

ISSN：1881-9311
Cell Dynamics Imaging with an Optical / Photoacoustic Hybrid Microscopy

新楯諒, 長岡亮, 石井琢郎, 西條芳文

超音波医学 Supplement　48　2021

ISSN：1881-9311
Three-dimensional photoacoustic imaging using a hemispherical array transducer and four way oblique laser irradiation

森野太介, 新楯諒, 林瑛己, 長岡亮, 吉澤晋, 梅村晋一郎, 西條芳文

超音波医学 Supplement　47　2020

ISSN：1881-9311
Development of high-resolution photoacoustic microscopy that enables clear imaging of cells

新楯諒, 長岡亮, 小林和人, 西條芳文

超音波医学 Supplement　47　2020

ISSN：1881-9311
Investigation of subcutaneous micro-vessels using photoacoustic microscopy

平塚竜基, 高橋爽, 菅野尚哉, 新楯諒, 梅村晋一郎, 西條芳文

超音波医学 Supplement　47　2020

ISSN：1881-9311
Statistical examination of sound velocity and acoustic impedance measured by an acoustic microscope

小林和人, 小林和人, 栗原唯生, 栗原唯生, 西條芳文, 穂積直裕

超音波医学 Supplement　47　2020

ISSN：1881-9311
高周波数帯域の光音響信号による細胞レベルのイメージング

西條芳文, 新楯諒, 高橋爽, 平塚竜基, 石井琢郎, 吉澤晋, 梅村晋一郎, 長岡亮, 岩崎秀明, 伊田泰一郎

乳腺甲状腺超音波医学　9　(4)　2020

ISSN：2187-2880
Imaging with Acoustic Resolution Photoacoustic Microscope using Annular Array Transducer

平塚竜基, 高橋爽, 佐藤滉太, 新楯諒, 梅村晋一郎, 石井琢郎, 石井琢郎, 西條芳文

電子情報通信学会技術研究報告(Web)　120　(174(US2020 27-42))　2020

ISSN：2432-6380
光超音波トモグラフィにおける光超音波信号の初期位相の補正による深さ分解能の改善に関する研究 : 高空間分解能化を目指して (特集超音波を使用した医療のあり方を探る(1))

長岡亮, 吉澤晋, 梅村晋一郎, 西條芳文

超音波techno　31　(3)　70-74　2019/05
Publisher: 日本工業出版
ISSN：0916-2410
大動脈弁狭窄症の心内血流動態の解析

皆川忠徳, 武田美貴, 平沼和希子, 松岡孝幸, 清水拓也, 三浦誠, 川本俊輔, 西條芳文

日本心臓血管外科学会学術総会抄録集　49回　[OP28-1]　2019/02
Publisher: (NPO)日本心臓血管外科学会
高周波数アニュラアレイセンサによる被写界深度の拡大

藤井佳祐, 佐藤泰, 菅野尚哉, 新楯諒, 小林和人, 吉澤晋, 梅村晋一郎, 西條芳文

電子情報通信学会技術研究報告　119　(211(US2019 46-56))　2019

ISSN：0913-5685
Comparative study of one-way vertical illumination and four-way oblique illumination in three-dimensional photoacoustic imaging using a hemispherical array transducer

森野太介, 新楯諒, 長岡亮, 吉澤晋, 梅村晋一郎, 西條芳文

電子情報通信学会技術研究報告　119　(211(US2019 46-56))　2019

ISSN：0913-5685
Visualization of skin morphology and microcirculation with high frequency ultrasound and dual-wavelength photoacoustic microscope

Yoshifumi Saijo, Taiichiro Ida, Hideaki Iwazaki, Jun Miyajima, Huabin Tang, Ryo Shintate, Kanta Sato, Tatsuki Hiratsuka, Shin Yoshizawa, Shinichiro Umemura

Progress in Biomedical Optics and Imaging - Proceedings of SPIE　10878　2019/01/01

DOI： 10.1117/12.2508599 　

ISSN：1605-7422

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© COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only. Skin aging is characterized by color and wrinkle caused by degeneration of collagen and elastin in the dermis. Recently, the volume, diameter and branching of the micro vessels in the skin are proved to affect these biomechanical changes. Thus, high resolution imaging for both micro structure and micro vessels of the skin is desired. In the present study, dual-wavelength photoacoustic microscope (PAM) combined with high frequency ultrasound (HFUS) is developed to visualize both the morphology and microcirculation of the skin. Two Nd:YAG laser light sources with the wavelength of 532/556 nm, pulse width of 1.2/3.6 ns, pulse energy of 16 μJ/pulse and repetition rate of 1 kHz were equipped in the HFUS-PAM system. The optical fiber for laser delivery was inserted through the center hole of the concave ultrasound transducer with the central frequency of 75 MHz. Both HFUS and PA signals were acquired at the sampling rate of 500 MHz and the resolution of 12 bits. The transducer was scanned by voice coil actuators to obtain 3D dataset of HFUS and PA signals. Oxygen saturation of the micro circulation was calculated by the PA signals alternately obtained at 532 nm and 556 nm. 3D image of the layered structure and the micro vessels representing oxygen saturation in the 6 mm x 6 mm x 3 mm volume of the skin was successfully obtained with the system. HFUS-PAM will provide important information of skin morphology and microcirculation for assessment of skin aging.
正常肩コンマサイン部を組織学的に研究する試み

新井隆三, 萩原嘉廣, 西條芳文, 馬谷直樹, 松田秀一

日本肩関節学会抄録集　45回　259-259　2018/09
Publisher: (一社)日本肩関節学会
High resolution photoacoustic imaging by multidirectional signal acquisition

佐藤幹太, 新楯諒, 藤原光浩, 西條芳文

電子情報通信学会技術研究報告　118　(229(US2018 49-62))　2018

ISSN：0913-5685
Design of transmission-mode photoacoustic microscopy using high frequency transducer

新楯諒, 長岡亮, 小林和人, 西條芳文

電子情報通信学会技術研究報告　118　(229(US2018 49-62))　2018

ISSN：0913-5685
ガルバノスキャンを用いた光音響イメージング用高速走査機構の開発

石川広大, 長岡亮, 板谷信行, 萩原嘉廣, 西條芳文

日本超音波医学会光超音波画像研究会プログラム・抄録集　2017　(4th)　7‐11　2018
Improvement of High Frequency Ultrasound Images by Point Spread Function Obtained with Optical Coherence Tomography

117　(227)　5-10　2017/10/05
Publisher: 電子情報通信学会
ISSN：0913-5685
心移植患者における心エコーによる左室拡張末期圧推定指標の有用性

藤原淳子, 青木竜男, 船水康陽, 三木俊, 西條芳文, 杉村宏一郎, 坂田泰彦, 秋山正年, 齋木佳克, 下川宏明

超音波医学　43　(Suppl.)　S602-S602　2016/04
Publisher: (公社)日本超音波医学会
ISSN：1346-1176

eISSN：1881-9311
頸動脈壁の粘弾性計測に関する検討

R. Nagaoka, M. Arakawa, S. Yoshizawa, S. Umemura, Y. Saijo, K. Kobayashi

超音波テクノ　28　(3)　10-14　2016
Publisher: 日本工業出版
1P5-11 Monitoring of High-Intensity Focused Ultrasound Treatment Using Shear Wave Elastography Induced by 2D Array Therapeutic Transducer

Iwasaki Ryosuke, Takagi Ryo, Nagaoka Ryo, Jimbo Hayato, Yoshizawa Shin, Saijo Yoshifumi, Umemura Shin-ichiro

Proceedings of Symposium on Ultrasonic Electronics　36　"1P5-11-1"-"1P5-11-2"　2015/11/05
Publisher: Steering committee of symposium on ultrasonic electronics
ISSN：1348-8236
癒着、瘢痕、拘縮の制御関節拘縮の機序

萩原嘉廣, 矢部裕, 金澤憲治, 小出将志, 関口拓矢, 西條芳文, 井樋栄二

日本整形外科学会雑誌　89　(8)　S1807-S1807　2015/09
Publisher: (公社)日本整形外科学会
ISSN：0021-5325
2P5-10 Detection of Thermally-Induced Lesion Using Shear Wave Imaging in Cavitation-Enhanced High-Intensity Focused Ultrasound Therapy(Poster Session)

Iwasaki Ryosuke, Nagaoka Ryo, Takagi Ryo, Goto Kota, Yoshizawa Shin, Saijo Yoshifumi, Umemura Shin-ichiro

Proceedings of Symposium on Ultrasonic Electronics　35　323-324　2014/12/03
Publisher: Steering committee of symposium on ultrasonic electronics
ISSN：1348-8236
3P5-19 A Basic Study of Intrinsic Elastography Based on Propagation Velocity Distribution Induced by Artery Pulsation(Poster Session)

Nagaoka Ryo, Iwasaki Ryosuke, Arakawa Mototaka, Kobayashi Kazuto, Yoshizawa Shin, Umemura Shin-ichiro, Saijo Yoshifumi

Proceedings of Symposium on Ultrasonic Electronics　35　545-546　2014/12/03
Publisher: Steering committee of symposium on ultrasonic electronics
ISSN：1348-8236
A Basic Study of Visualization of Propagation Velocity Distribution Induced by Arterial Pulsation

Nagaoka Ryo, Arakawa Mototaka, Kobayashi Kazuto, Yoshizawa Shin, Umemura Shin-ichiro, Saijo Yoshifumi

The Computational Mechanics Conference　2014　(27)　362-363　2014/11/22
Publisher: The Japan Society of Mechanical Engineers
ISSN：1348-026X
Estimation of blood flow vectors based on ultrasonic Doppler method

The Computational Mechanics Conference　2014　(27)　364-365　2014/11/22
Publisher: The Japan Society of Mechanical Engineers
ISSN：1348-026X
ラット膝関節拘縮モデルにおけるヒアルロン酸の関節拘縮予防効果の検討

金澤憲治, 萩原嘉廣, 土谷昌広, 矢部裕, 園淵和明, 小出将志, 安藤晃, 関口拓矢, 西條芳文, 井樋栄二

日本整形外科学会雑誌　88　(8)　S1655-S1655　2014/08
Publisher: (公社)日本整形外科学会
ISSN：0021-5325
光音響イメージングによるミクロレベルの組織血流評価

西條芳文, 佐藤みか, 山崎玲奈, 長岡亮, 鷲尾勝由, 松浦祐司

超音波医学　41　(Suppl.)　S203-S203　2014/04/15
Publisher: (公社)日本超音波医学会
ISSN：1346-1176
ソノサイトメトリーの基盤技術の検討

小松洋介, 長岡亮, 船本健一, 早瀬敏幸, 政氏伸夫, 金井浩, 西條芳文

超音波医学　41　(Suppl.)　S481-S481　2014/04
Publisher: (公社)日本超音波医学会
ISSN：1346-1176
2B41 Recent development of ultrasound microscope for biomedical applications

SAIJO Yoshifumi

2014　(26)　325-326　2014/01/10
Publisher: The Japan Society of Mechanical Engineers
2B42 Measurement of skin elasticity by high frequency ultrasound

NAGAOKA Ryo, KOBAYASHI Kazuto, SAIJO Yoshifumi

2014　(26)　327-328　2014/01/10
Publisher: The Japan Society of Mechanical Engineers
2P5-2 High Frequency Ultrasound Measurement of Micro Displacement in Human Skin Induced by Arterial Pulsation(Poster Session)

Nagaoka Ryo, Kobayashi Kazuto, Saijo Yoshifumi

Proceedings of Symposium on Ultrasonic Electronics　34　303-304　2013/11/20
Publisher: Steering committee of symposium on ultrasonic electronics
ISSN：1348-8236
3J5-3 Characterization of Single Cell Properties Using High-frequency Ultrasound(Biomedical Ultrasound 1)

Yoshida Koki, Abuhabsah Rami, Pawlicki Alexander D., Shikama Joe, Nagaoka Ryo, Saijo Yoshifumi, O'Brien William D. Jr

Proceedings of Symposium on Ultrasonic Electronics　34　395-396　2013/11/20
Publisher: Steering committee of symposium on ultrasonic electronics
ISSN：1348-8236
2P5-4 Three-dimensional Photoacoustic Imaging of Chicken Embryo Vasculature(Poster Session)

Sato Mika, Yamazaki Rena, Watanabe Yuji, Nakamura Harukazu, Matsuura Yuji, Saijo Yoshifumi

Proceedings of Symposium on Ultrasonic Electronics　34　307-308　2013/11/20
Publisher: Steering committee of symposium on ultrasonic electronics
ISSN：1348-8236
3P5-19 Two-dimensional Blood Flow Vector obtained by Bidirectional Doppler Ultrasound with Parallel Beamforming(Poster Session)

Masuno Genta, Nagaoka Ryo, Sasaki Shoya, Yoshizawa Shin, Umemura Shinichiro, Saijo Yoshifumi

Proceedings of Symposium on Ultrasonic Electronics　34　527-528　2013/11/20
Publisher: Steering committee of symposium on ultrasonic electronics
ISSN：1348-8236
Acoustic characteristic analysis of fatty and fibrosis rat liver by using 80 MHz and 250 MHz bioacoustic microscopy

Inoue Kenta, Mamou Jonathan, Kobayashi Kazuto, Saijo Yoshifumi, Yamaguchi Tadashi

IEICE technical report. Ultrasonics　113　(13)　21-26　2013/04/23
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN：0913-5685

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Ultrasonic quantitative diagnosis are beginning to use in clinical site. It is first necessary to understand the relationship between the characteristics of echo signal and tissue property. Towards this aim, speed-of-sound (SOS) and attenuation from three types of rat livers (normal, fatty and fibrosis) were measured with a scanning bioacoustic microscopy with transducers of 80 MHz and 250 MHz center frequencies. The results of calculation of SOS and attenuation were compared with histology of each tissue sample.
微小レベルにおける局所心筋の収縮-弛緩・伸展特性(位相差トラッキング法を用いた心筋壁動態解析)

田渕晴名, 片平美明, 田中元直, 中島博行, 坂本二哉, 菅原重生, 亀山剛義, 長谷川英之, 金井浩, 西條芳文

日本心エコー図学会学術集会抄録集　24th　2013
3Pb5-5 Measurement of Micro-displacement of Polyvinyl Alcohol Induced by Acoustic Radiation Force : Comparison of Laser-Doppler Velocimetry and High Frequency Ultrasound(Poster Session)

Nagaoka Ryo, Izumi Takuya, Komatsu Yosuke, Kobayashi Kazuto, Saijo Yoshifumi

Proceedings of Symposium on Ultrasonic Electronics　33　487-488　2012/11/13
Publisher: Steering committee of symposium on ultrasonic electronics
ISSN：1348-8236
3Pa5-5 Development of blood flow velocity estimation method from Doppler echocardiography and its validation by MRI data(Poster Session)

Kojima Takanori, Nakajima Hiroyuki, Kurokawa Takafumi, Kameyama Takeyoshi, Tabuchi Haruna, Omori Aiko, Saijo Yoshifumi

Proceedings of Symposium on Ultrasonic Electronics　33　381-382　2012/11/13
Publisher: Steering committee of symposium on ultrasonic electronics
ISSN：1348-8236
Characterization of rat liver tissue by measuring the acoustic characteristics in high frequency

INOUE Kenta, MAMOU Jonathan, KOBAYASHI Kazuto, SAIJO Yoshifumi, YAMAGUCHI Tadashi

超音波エレクトロニクスの基礎と応用に関するシンポジウム講演予稿集　33rd　481-482　2012/11/13

ISSN：1348-8236
Information on Rescue Activity

SAIJO Yoshifumi

The Journal of the Institute of Electronics, Information, and Communication Engineers　95　(10)　899-903　2012/10/01
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN：0913-5693
難治性五十肩の病態

萩原嘉廣, 安藤晃, 土谷昌広, 高橋憲正, 西條芳文, 菅谷啓之, 井樋栄二

日本整形外科学会雑誌　86　(8)　S1097-S1097　2012/08
Publisher: (公社)日本整形外科学会
ISSN：0021-5325
Engineering analysis of the effects of bulging sinus in a newly designed paediatric pulmonary heart valve on hemodynamic function

SUZUKI Ichiro, YABE Shota, MATSUE Ken, SUGAI Telma Keiko, TSUBOKO Yusuke, SAIJO Yoshifumi, YOSHIZAWA Makoto, KAMEYAMA Takeyoshi, SHIRAISHI Yasuyuki, YAMBE Tomoyuki, FENG Zhonggang, OKAMOTO Yoshihiro, TANAKA Takashi, UMEZU Mitsuo, MIYAZAKI Takako, YAMAGISHI Masaaki

人工臓器　41　(1)　59-61　2012/06/15

DOI： 10.1007/s10047-011-0609-1 　

ISSN：0300-0818
超音波顕微鏡観察における,金属イオン試薬添加を利用した観察法の検討

小林和人, 吉田祥子, 穂積直裕, 西條芳文

超音波医学　39　S358　2012/04/15

ISSN：1346-1176
左心房収縮と流入血による渦の発生

山家智之, 亀山剛義, 秋野能久, 西條芳文, 田中元直

日本臨床生理学会雑誌　42　(5)　2012

ISSN：0286-7052
Blood Flow Structure in Patients with Dilated Cardiomyopathy Studied using Echo-dynamography

亀山剛義, 山家智之, 白石泰之, 西條芳文, 田中元直

日本臨床生理学会雑誌　42　(3)　2012

ISSN：0286-7052
Engineering Analysis of the Effects of Bulging Sinus in a Newly Designed Paediatric Pulmonary Heart Valve on Hemodynamic Function

鈴木一郎, 鈴木一郎, 矢部翔太, 末永健, SUGAI Telma Keiko, 坪子侑佑, 西條芳文, 吉澤誠, 亀山剛義, 白石泰之, 山家智之, 馮忠剛, 岡本吉弘, 田中隆, 梅津光生, 宮崎隆子, 山岸正明

東北医学雑誌　124　(1)　2012

ISSN：0040-8700
左室乳頭筋モデルによる僧帽弁機能の基礎検討

橋本尚, 白石泰之, SUGAI Telma Keiko, 志賀卓弥, 古賀千尋, 山田昭博, 坪子侑佑, 三浦英和, 西條芳文, 山家智之, 本間大

生体医工学　50　(4)　2012

ISSN：1347-443X
超音波顕微鏡を用いた心筋症診断の可能性

中村陽一, 小林和人, 草野研吾, 穂積直裕, 西條芳文

日本心エコー図学会学術集会抄録集　23rd　90　2012
1P1-1 Photoacoustic imaging of knee cartilage mouse using а semiconductor laser(Poster Session)

Izumi Takuya, Miida Yusuke, Nagaoka Ryo, Sato Mika, Matsuura Yuji, Hagiwara Yoshihiro, Saijo Yoshifumi

Proceedings of Symposium on Ultrasonic Electronics　33　(0)　19-20　2012
Publisher: Institute for Ultrasonic Elecronics
DOI： 10.24492/use.33.0_19 　

ISSN：1348-8236
2Pa5-13 Acoustic characteristics measurement of rat liver by multi-frequency ultrasound(Poster Session)

TAKEUCHI Yoichiro, NARISAWA Ryo, HACHIYA Hiroyuki, SAIJO Yoshifumi, KOBAYASHI Kazuto, YAMAGUCHI Tadashi

Proceedings of Symposium on Ultrasonic Electronics　32　159-160　2011/11/08
Publisher: Steering committee of symposium on ultrasonic electronics
ISSN：1348-8236
中空光ファイバを用いた光音響イメージングと光音響効果の色依存性

小池秀幸, 熊谷和敏, 和泉拓哉, 三井田佑輔, 穂積直裕, 松浦祐司, 西條芳文

超音波医学　38　S463　2011/04/15

ISSN：1346-1176
Aberration Correction for Biological Acoustic Impedance Microscope and Observation of Rat Cerebella Tissue

UEMURA Tsutomu, SUZUKI Takaya, HANAI Kunihiko, HOZUMI Naohiro, KOBAYASHI Kazuto, YOSHIDA Sachiko, YAMAMOTO Seiji, SAIJO Yoshifumi

電気学会研究会資料. DEI, 誘電・絶縁材料研究会　2011　(1)　53-56　2011/01/19
8F-07 Preliminary study on the effect of papillary tension on valvular leakage for the development of a new artificial papillary muscle using shape memory alloy fiber

HASHIMOTO Hisashi, SHIRAISHI Yasuyuki, SUGAI Telma KEIKO, KONNO Satoshi, MIURA Hidekazu, SAIJO Yoshifum, YAMBE Tomoyuki, HOMMA Dai

2010　(23)　109-110　2011/01/07
Publisher: The Japan Society of Mechanical Engineers
医用超音波イメージング最近の展開

西條芳文, 田上英毅, 中島博行

ナノ医工学年報　5　(1)　131-140　2011
Publisher: 東北大学グローバルCOEプログラム「新世紀世界の成長焦点に築くナノ医工学拠点」
ISSN：1882-4692
情報通信技術 (ICT) は医療福祉問題の救世主か？

吉澤誠, 杉田典大, 阿部誠, 西條芳文, 本間経康, 金野敏, 山家智之, 仁田新一

生体医工学　49,　(2)　387-389　2011
Publisher: 日本生体医工学会
DOI： 10.11239/jsmbe.49.387 　

ISSN：1347-443X
PP-576 超音波音速顕微鏡で観察した前立腺組織～予備的報告(発表・討論,一般演題ポスター,第99回日本泌尿器科学会総会)

田上英毅, 小林和人, 西條芳文, 萩原嘉廣, 浦田洋二, 上田朋宏

日本泌尿器科学会雑誌　102　(2)　500-500　2011
Publisher: 一般社団法人日本泌尿器科学会
DOI： 10.5980/jpnjurol.102.500_1 　

ISSN：0021-5287
Preliminary study on the development of a new artificial papillary muscle using shape memory alloy fiber

HASHIMOTO Hisashi, SHIRAISHI Yasuyuki, SUGAI Telma Keiko, KONNO Satoshi, MIURA Hidekazu, SAIJO Yoshifum, YAMBE Tomoyuki, HOMMA Dai

2010　(45)　13-16　2010/11/20
高分子フィルム型超音波振動子のインパルス応答を利用した脳腫瘍の観察と画像処理

鈴木貴也, 花井邦彦, 植村努, 穂積直裕, 小林和人, 吉田祥子, 山本清二, 西條芳文

電気電子絶縁材料システムシンポジウム　2010/11
セラミック超音波振動子による細胞観察

花井邦彦, 植村努, 鈴木貴也, 穂積直裕, 小林和人, 吉田祥子, 山本清二, 西條芳文

電気電子絶縁材料システムシンポジウム　2010/11
REVERSIBILITY OF IMMOBILIZATION-INDUCED ARTICULAR CARTILAGE DEGENERATION AFTER REMOBILIZATION IN RAT KNEE JOINTS

A. Ando, H. Suda, Y. Hagiwara, Y. Onoda, E. Chimoto, Y. Saijo, E. Itoi

OSTEOARTHRITIS AND CARTILAGE　18　S92-S93　2010/10
Publisher: W B SAUNDERS CO LTD
ISSN：1063-4584
超音波によるラットの脳腫瘍モデルの観察と定量解析

鈴木貴也, 植村努, 花井邦彦, 穂積直裕, 小林和人, 吉田祥子, 山本清二, 西條芳文

電気関係学会東海支部連合大会講演論文集(CD-ROM)　2010　ROMBUNNO.B2-9　2010/08/27
生体観察用光音響顕微鏡のための高速スキャンシステム開発

小池秀幸, 熊谷和敏, 穂積直裕, 植村努, 松浦祐司, 西條芳文

超音波医学　37　S347　2010/04/15

ISSN：1346-1176
三次元複合臓器構造体研究開発における高周波数超音波の応用

西條芳文, 萩原嘉廣, 羽鳥弘毅, 小林和人, 穂積直裕, 田中明, 中村憲正, 星和人

超音波医学　37　(Suppl.)　S346-S346　2010/04
Publisher: (一社)日本超音波医学会
ISSN：1346-1176
超音波によるラットの脳腫瘍モデルの観察と画像処理

鈴木貴也, 植村努, 花井邦彦, 穂積直裕, 小林和人, 吉田祥子, 山本清二, 西條芳文

電気学会全国大会講演論文集　2010　(1)　153　2010/03/05
2次元音響インピーダンス測定機能付き3次元超音波顕微鏡を実現するための複合焦点振動子

花井邦彦, 植村努, 鈴木貴也, 穂積直裕, 小林和人, 吉田祥子, 山本清二, 西條芳文

電気学会全国大会講演論文集　2010　(1)　154　2010/03/05
0406 Preliminary examination of an engineering control for hemodynamic assistance by the artificial myocardium using shape memory alloy fibre

SATO Yuta, UMEZU Mitsuo, FUJIMOTO Tatsuo, SHIRAISHI Yasuyuki, MIURA Hidekazu, KONNO Satoshi, YAMBE Tomoyuki, KANEKO Yoshikazu, SUGAI Telma Keiko, YABE Shota, SAIJO Yoshifumi, BABA Atsushi, Homma Dai

2009　(22)　58-58　2010/01/08
Publisher: The Japan Society of Mechanical Engineers
Bulging sinusを有するePTFE心臓代用弁の工学的評価

白石泰之, 鈴木一郎, 矢部翔太, SUGAI Telma K, 山田昭博, 亀山剛義, 金子芳一, 北野智哉, 田中隆, 金野敏, 西條芳文, 梅津光生, 宮崎隆子, 山岸正明, 山家智之

人工臓器(日本人工臓器学会)　39　(2)　2010

ISSN：0300-0818
Effect of Feedback of Zeroed Doppler Velocity on Ultrasonic-Measurement-Integrated Simulation of Blood Flow

Funamoto Kenichi, Hayase Toshiyuki, Saijo Yoshifumi, Yambe Tomoyuki

2010　216-216　2010
Publisher: 日本流体力学会

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Ultrasonic-measurement-integrated (UMI) simulation, in which feedback signals are applied to the governing equations based on errors between ultrasonic measurement and numerical simulation, has been investigated for reproduction of the blood flow field. In this study, the effects of wall filter and lack of data, which provide zero Doppler velocity, on UMI simulation were examined by a numerical experiment dealing with the blood flow field in the descending aorta with an aneurysm. Effects of wall filter and lack of data appeared in diastole and in the whole period, respectively. However, by not adding feedback signals where measured Doppler velocities were zero, the computational accuracy of the UMI simulation substantially improved for the sake of the feedback.
｢超｣常識｢超｣音波イメージングの医学・生物学への応用

西條芳文, 小林和人, 田上英毅

ナノ医工学年報　4　(1)　123-130　2010
Publisher: 東北大学グローバルCOEプログラム「新世紀世界の成長焦点に築くナノ医工学拠点」
ISSN：1882-4692
A102 Evaluation of hemodynamic characteristics of the newly designed paediatric pulmonary heart valve by using a high speed video camera

YABE Shota, SUZUKI Ichiro, Sugai Telma Keiko, SAIJO Yosifumi, MIURA Hidekazu, LIU Hong Jian, KONNO Satoshi, SHIRAISHI Yasuyuki, YAMBE Tomoyuki, TANAKA Takashi, UMEZU Mitsuo, MIYAZAKI Takako, YAMAGISHI Masaaki

Proceedings of the ... JSME Conference on Frontiers in Bioengineering　2009　(20)　5-6　2009/11/06
Publisher: The Japan Society of Mechanical Engineers
ISSN：1348-2939
B213 Blood Flow Simulation Integrated with Ultrasonic Measurement 9^<th> Report : Effect of Noise in Ultrasonic Measurement

FUNAMOTO Kenichi, HAYASE Toshiyuki, SAIJO Yoshifumi, YAMBE Tomoyuki

Proceedings of the ... JSME Conference on Frontiers in Bioengineering　2009　(20)　117-118　2009/11/06
Publisher: The Japan Society of Mechanical Engineers
ISSN：1348-2939
Basic study on the sophisticated control for the intelligent artificial myocardium

SHIRAISHI Yasuyuki, MIURA Hidekazu, YAMBE Tomoyuki, SUGAI Telma Keiko, SAIJO Yoshifumi, SATO Yuta, FUJIMOTO Tetsuo, UMEZU Mitsuo, BABA Atsushi, FUKUNAGA Kazuyoshi, TANAKA Akira, HOMMA Dai

2009　(34)　37-42　2009/10/20
509 Basic characteristics of the newly designed paediatric pulmonary circulatory simulator

YABE Shota, SUZUKI Ichiro, SUGAI Telma Keiko, SAIJO Yosifumi, MIURA Hidekazu, LIU Hong Jian, KONNO Satoshi, SHIRAISHI Yasuyuki, YAMBE Tomoyuki, TANAKA Takashi, UMEZU Mitsuo, MIYAZAKI Takako, YAMAGISHI Masaaki

2009　(45)　145-146　2009/09/26
Publisher: The Japan Society of Mechanical Engineers
508 Preliminary study on the new bioengineering approach for surgical planning of ventricular reconstruction

SHIRAISHI Yasuyuki, LIN Hui, SUGAI Telma Keiko, UEMATSU Miyuki, SAIJO Yoshifumi, TANAKA Akira, UMEZU Mitsuo, YAMBE Tomoyuki, TABAYASHI Koichi

2009　(45)　143-144　2009/09/26
Publisher: The Japan Society of Mechanical Engineers
三次元高周波数超音波イメージングによる皮膚組織の微細構造の観察

西條芳文, 小林和人, 田中明, 穂積直裕

超音波医学　36　S301　2009/04/15

ISSN：1346-1176
生体組織の固有音響インピーダンスを評価するための簡易計測プローブの提案

小林和人, 森屋健司, 穂積直裕, 西條芳文

超音波医学　36　S294　2009/04/15

ISSN：1346-1176
パラフィン包埋標本作成過程において組織音速に影響を及ぼす因子の検討

中村陽一, 小林和人, 中村一文, 草野研吾, 穂積直裕, 吉田祥子, 鈴木誠, 西條芳文

超音波医学　36　(Suppl.)　S293-S293　2009/04
Publisher: (公社)日本超音波医学会
ISSN：1346-1176

eISSN：1881-9311
PJ-061 Visualization of Micro-vessel by Three-dimensional Ultrasound Microscope(PJ010,Echo/Doppler (New Technology) 2 (I),Poster Session (Japanese),The 73rd Annual Scientific Meeting of The Japanese Circulation Society)

Saijo Yoshifumi, Kobayashi Kazuto, Tanaka Akira

Circulation journal : official journal of the Japanese Circulation Society　73　561-561　2009/03/01
Publisher: Japanese Circulation Society
ISSN：1346-9843
OE-076 Ultrasonic Tissue Deformation Imaging to Evaluate Myocardial Dyssynchrony(OE13,Echo/Doppler (New Technology) (I),Oral Presentation (English),The 73rd Annual Scientific Meeting of The Japanese Circulation Society)

Saijo Yoshifumi, Tanaka Akira

Circulation journal : official journal of the Japanese Circulation Society　73　193-193　2009/03/01
Publisher: Japanese Circulation Society
ISSN：1346-9843
多次元の血圧反射機能感受性定量診断 (心臓リハビリテーション)

山家智之, 金野敏, 西條芳文, 白石泰之, 仁田新一, 上月正博, 吉澤誠, 杉田典大, 田中明, 山口済, 片平美明, 秋野能久, 柴田宗一, 渡辺誠, 三引義明, 大沢上, 佐藤尚

心臓リハビリテーション　14　(1)　108-114　2009/02
橈骨動脈血流量に関する鍼治療の効果太衝穴による血行動態変化

高山真, 関隆志, 山家智之, 西條芳文, 金野敏, 沖津玲奈, 岩崎鋼, 荒井啓行, 八重樫伸生, 仁田新一

日本内科学会雑誌　98　(Suppl.)　218-218　2009/02
Publisher: (一社)日本内科学会
ISSN：0021-5384

eISSN：1883-2083
139 Mechanical design of the totally implantable artificial myocardial assist device by using shape memory alloy fibre

SHIRAISHI Yasuyuki, SAKATA Ryo, SATO Yuta, KONNO Satoshi, SUGAI Telma Keiko, BABA Atsushi, FUJIMOTO Tetsuo, UMEZU Mitsuo, IMACHI Kou, SAIJO Yoshifumi, YAMBE Tomoyuki, Homma Dai

2008　(21)　307-308　2009/01/22
Publisher: The Japan Society of Mechanical Engineers
326 Blood Flow Simulation Integrated with Ultrasonic Measurement 8th Report : Effect of Error in Ultrasonic Measurement

FUNAMOTO Kenichi, HAYASE Toshiyuki, SAIJO Yoshifumi, YAMBE Tomoyuki

2008　(21)　353-354　2009/01/22
Publisher: The Japan Society of Mechanical Engineers
流軸線上速度勾配測定法による左室拡張能評価(第一報)-Echo-dynamographyによる解析-

中島博行, 田中元直, 菅原重生, 片平美明, 亀山剛義, 大槻茂雄, 西條芳文

日本心エコー図学会学術集会抄録集　20th　2009
左室内におけるLate Systolic Reversal Flow-Echo-Dynamographyによる血流解析-

亀山剛義, 菅原重生, 片平美明, 田中元直, 中島博行, 大槻茂雄, 西條芳文

日本心エコー図学会学術集会抄録集　20th　2009
流軸線上速度分布による定量的心機能評価法の検討(第二報)

中島博行, 田中元直, 菅原重生, 片平美明, 亀山剛義, 大槻茂雄, 西條芳文

超音波医学　36　2009

ISSN：1346-1176
脈のない人工心臓と，脈の診断

山家智之, 白石泰之, 金野敏, 馬場篤志, 井街宏, 田林晄一, 西條芳文, 杉田典大, 吉沢誠, 上月博, 阿部裕輔, 斎藤逸郎, 磯山隆, 山崎健二, 北野智哉, 山崎俊一, 亀山剛義, 秋野能久, 山口済, 片平美明, 柴田宗一, 大沢上, 佐藤尚

宮城県医師会報　755　12　2008/12/01
23) 左心補助人工心臓から離脱した拡張型心筋症の1例(第146回日本循環器学会東北地方会)

井口篤志, 二宮本報, 田林晄一, 西條芳文

Circulation journal : official journal of the Japanese Circulation Society　72　1054-1054　2008/10/20
Publisher: 社団法人日本循環器学会
ISSN：1346-9843
1E3-5 Improvement of the artificial myocardial assistance for chronic animal experiment

SATO Yuta, SHIRAISHI Yasuyuki, SAKATA Ryo, LIN Hui, TANAKA Takashi, UMEZU Mitsuo, KONNO Satoshi, SAIJO Yoshifumi, SUGAI Telma Keiko, YOSHIZAWA Makoto, YAMBE Tomoyuki, BABA Atsushi, MASUMOTO Noriyasu, FUJIMOTO Tetsuo, Homma Dai

The JSME Symposium on Welfare Engineering　2008　135-136　2008/09/17
Publisher: The Japan Society of Mechanical Engineers
超音波顕微鏡の培養細胞への応用

萩原嘉廣, 西條芳文, 安藤晃, 千本英一, 小野田祥人, 須田英明, 井樋栄二

日本整形外科学会雑誌　82　(8)　S1018-S1018　2008/08/25
Publisher: (公社)日本整形外科学会
ISSN：0021-5325
皮膚組織の3次元超音波顕微鏡像

西條芳文, 岩本貴宏, 小林和人, 岡田長也, 萩原嘉廣, 田中明, 穂積直裕

超音波医学　35　(4)　469　2008/07/15

ISSN：1346-1176
Present status of medical application of acoustic microscopy

SAIJO Yoshifumi

The Journal of the Acoustical Society of Japan　64　(7)　418-422　2008/07/01
Publisher: The Acoustical Society of Japan (ASJ)
ISSN：0369-4232
Quantitative analysis of the regional myocardial function by the velocity distribution of flow axis line

NAKAJIMA Hiroyuki, SUGAWARA Shigeo, KATAHIRA Yoshiaki, TANAKA Motonao, KAMEYAMA Takeyoshi, OHTUKI Shigeo, SAIJO Yoshifumi

35　S359　2008/04/15

ISSN：1346-1176
High frequency ultrasonic imaging

SAIJO Yoshifumi

35　S185　2008/04/15

ISSN：1346-1176
637 Mechanical analysis of morphological structure of a heart for more sophisticated design of the artificial myocardium

SHIRAISHI Yasuyuki, SAIJO Yoshifumi, YAMBE Tomoyuki, SHIBATA Muneichi, WADA Yumiko, SAKATA Ryo, WATABE Tomoki, UMEZU Mitsuo, FUJIMOTO Tetsuo, BABA Atsushi, TABAYASHI Koichi, Homma Dai

2007　(20)　433-434　2008/01/24
Publisher: The Japan Society of Mechanical Engineers
Artificial Myocardial Assistance using the Sophisticated Shape Memory Alloy Fibre Based on Engineering Approach for Cardiac Mechanics

SHIRAISHI Yasuyuki, YAMBE Tomoyuki, SAIJO Yoshifumi, SHIBATA Muneichi, MASUDA Shinya, TABAYASHI Koichi, UMEZU Mitsuo, HOMMA Dai

電気学会研究会資料. LD, リニアドライブ研究会　2007　(32)　85-88　2007/10/25
A111 Mechanical simulation for myocardial contractile assistance based on controllability of a sophisticated shape memory alloy fibre

SAKATA Ryo, SHIRAISHI Yasuyuki, WADA Yumiko, WATABE Tomoki, UEMATSU Miyuki, TANAKA Takashi, PARK Young Kwang, UMEZU Mitsuo, SEKINE Kazumitsu, KONNO Satoshi, SAIJO Yoshifumi, YAMBE Tomoyuki, TANAKA Akira, YOSHIZAWA Makoto, MASUMOTO Noriyasu, FUJIMOTO Tetsuo, HOMMA Dai

Proceedings of the ... JSME Conference on Frontiers in Bioengineering　2007　(18)　21-22　2007/10/05
Publisher: The Japan Society of Mechanical Engineers
ISSN：1348-2939
Propagation of electric excitation in human heart is visualized by transthoracic echocardiography

Hiroshi Kanai, Yoshifumi Saijo

CIRCULATION　116　(16)　501-502　2007/10
Publisher: LIPPINCOTT WILLIAMS & WILKINS
ISSN：0009-7322
ラット膝関節不動化モデルにおける関節包組織の音速(粘弾性)の経時的変化

萩原嘉廣, 千本英一, 安藤晃, 西條芳文, 笹野泰之, 井樋栄二

日本整形外科学会雑誌　81　(8)　S1041-S1041　2007/08/25
Publisher: (公社)日本整形外科学会
ISSN：0021-5325
(J Vasc Med)

Saijo Yoshifumi

J Vasc Med　3　(3)　45-52　2007/07/01
Clinical application of parametric IVUS imaging (Jap J Cardiovasc Cathet Therap)

Saijo Yoshifumi

Jap J Cardiovasc Cathet Therap　7　(2)　131-139　2007/06
Acoustic Impedance Microscopy for Tissue Characterization

KOBAYASHI Kazuto, HOZUMI Naohiro, SAIJO Yoshifumi, YOSHIDA Sachiko, OHTSUKI Shigeo

Journal of medical ultrasonics = 超音波医学　34　S324　2007/04/15

ISSN：1346-1176
Image Processing for Ultrasonic Microscope Considering Its Beam Characteristics

KOBAYASHI Kazuto, ISHIGURO Toshimichi, HOZUMI Naohiro, SAIJO Yoshifumi, OHTSUKI Shigeo

Journal of medical ultrasonics = 超音波医学　34　S313　2007/04/15

ISSN：1346-1176
Visualization of Fibroblast by in vivo Ultrasonic Nano-imaging

SAIJO Yoshifumi, HOZUMI Naohiro, KOBAYASHI Kazuto, DOS SANTOS FILHO Esmeraldo

Journal of medical ultrasonics = 超音波医学　34　S310　2007/04/15

ISSN：1346-1176
PE-059 Two-dimensional Blood Flow Vector Imaging of Retardant Flow in Left Atrium(Echo/Doppler-08, The 71st Annual Scientific Meeting of the Japanese Circulation Society)

Saijo Yoshifumi, Tanaka Akira, Yambe Tomoyuki

Circulation journal : official journal of the Japanese Circulation Society　71　339-340　2007/03/01
Publisher: Japanese Circulation Society
ISSN：1346-9843
OE-089 Development of IVUS Attenuation Imaging and Comparison with Multiple Parametric Imagings(Intravascular endoscopy/Intravascular ultrasound-1, The 71st Annual Scientific Meeting of the Japanese Circulation Society)

Saijo Yoshifumi, Tanaka Akira, Filho Esmeraldo dos Santos, Iwamoto Takahiro, Yambe Tomoyuki

Circulation journal : official journal of the Japanese Circulation Society　71　173-174　2007/03/01
Publisher: Japanese Circulation Society
ISSN：1346-9843
医用超音波ナノ・イメージング＝周波数500MHzの医学用超音波音速顕微鏡の開発＝ (超音波TECHNO)

SAIJO Yoshifumi

超音波TECHNO　19　(1)　4-9　2007/01/20
Publisher: 日本工業出版
ISSN：0916-2410
309 Blood Flow Simulation Integrated with Ultrasonic Measurement : 7^<th> Report: Effect of Time Resolution of Measurement

FUNAMOTO Kenichi, HAYASE Toshiyuki, SAIJO Yoshifumi, YAMBE Tomoyuki

2006　(19)　68-69　2007/01/06
Publisher: The Japan Society of Mechanical Engineers
人工心筋収縮構造制御による補助効率最適化に関する基礎検討

白石泰之, 山家智之, 関根一光, 西條芳文, 金野敏, 仁田新一, 和田由美子, 坂田亮, 梅津光生, 小川大祐, 佐藤文博, 角張泰之, 田中明, 吉澤誠, 本間大

日本生体医工学会大会プログラム・論文集(CD-ROM)　46th　2007
形状記憶合金を応用した消化管蠕動運動補助装置

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

日本生体医工学会大会プログラム・論文集(CD-ROM)　46th　2007
生体心臓の構造を考慮した人工心筋開発の試み

白石泰之, 山家智之, 関根一光, 西條芳文, 金野敏, 仁田新一, 和田由美子, 坂田亮, 伊藤慎二, 植松美幸, PARK Youngkwang, 田中隆, 梅津光生, 小川大祐, 角張泰之, 佐藤文博, 田中明, 吉澤誠, 増本憲泰, 藤本哲男, 本間大, 馬場敦, 井街宏, 佐々田比呂志, 田林晄一

バイオエンジニアリング講演会講演論文集　19th　2007

ISSN：1348-2920
Ultrasound speed and impedance microscopy for in vivo imaging. International-journal

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

Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference　2007　1350-3　2007

ISSN：1557-170X

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Ultrasound speed and impedance microscopy was developed in order to develop in vivo imaging system. The sound speed mode realized non-contact high resolution imaging of cultured cells. This mode can be applied for assessment of biomechanics of the cells and thinly sliced tissues. The impedance mode visualized fine structures of the surface of the rat's brain. This mode can be applied for intra-operative pathological examination because it does not require slicing or staining.
340 Development of linear actuator as a peristaltic motion assist device

Sekine Kazumitsu, Nakazawa Fumio, Shiraishi Yasuyuki, Yambe Tomoyuki, Saijo Yoshifumi, Ohta Makoto, Hori Yoshio, Matsuki Hidetoshi, Sato Fumihiro, Maeda Tsuyoshi

The Proceedings of the Bioengineering Conference Annual Meeting of BED/JSME　2006　(0)　336-337　2007
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmebio.2006.19.336 　
ラット膝関節不動化モデルにおける関節包組織の粘弾性の経時的変化

萩原嘉廣, 千本英一, 安藤晃, 西條芳文, 笹野泰之, 国分正一, 井樋栄二

日本結合組織学会学術大会抄録集　39th　133　2007
B102 Design improvement of a newly designed artificial myocardial belt

WADA Yumiko, SHIRAISHI Yasuyuki, ITOH Shinji, SAKATA Ryo, UEMATSU Miyuki, TANAKA Takashi, PARK Young Kwang, UMEZU Mitsuo, SEKINE Kazumitsu, KONNO Satoshi, SAIJO Yoshifumi, YAMBE Tomoyuki, Nitta Shinichi, TANAKA Akira, YOSHIZAWA Makoto, MASUMOTO Noriyasu, FUJIMOTO Tetsuo, HOMMA Dai

Proceedings of the ... JSME Conference on Frontiers in Bioengineering　2006　(17)　43-44　2006/11/10
Publisher: The Japan Society of Mechanical Engineers
ISSN：1348-2939
1306 Numerical Experiment of Ultrasonic-Measurement-Integrated Simulation for Three-Dimensional Unsteady Blood Flow(1)

FUNAMOTO Kenichi, HAYASE Toshiyuki, SAIJO Yoshifumi, YAMBE Tomoyuki

Fluids engineering conference ...　2006　"1306-a"　2006/10/28
Publisher: The Japan Society of Mechanical Engineers
ISSN：1348-2882
Development of peristaltic motion assist device for using helicoidal shape memory alloy against digestive organs cancer

SEKINE Kazumitsu, YAMBE Tomoyuki, SHIRAISHI Yasuyuki, SAIJO Yoshifumi, HORI Yoshio, MATSUKI Hidetoshi, SATO Fumihiro, NITTA Shin-ichi, MAEDA Tsuyoshi

2006　(48)　69-73　2006/10/26
特集 DES時代のBeyond Angiography Virtual Histologyの基礎 (Coronary Intervention )

西條芳文

Coronary Intervention　2　(1)　82-87　2006/05
拡張型心筋症における心筋音速とIntegrated Backscatterとの関係

中村陽一, 高橋昇, 小松須美生, 小林和人, 穂積直裕, 西条芳文, 中村一文, 草野研吾, 大江透

超音波医学　33　S540　2006/04/15

ISSN：1346-1176
100MHz超音波による肝組織の3次元イメージング

西条芳文, 岡田長也, 小林和人, 穂積直裕, SANTOS FILHO Esmeraldo Dos, 白石泰之, 関根一光, 山家智之

超音波医学　33　S315　2006/04/15

ISSN：1346-1176
心筋の弾性からみた新しい病理組織診断の試み‐超音波顕微鏡を用いた検討‐

中村陽一, 高橋昇, 小松須美生, 大郷恵子, 中村一文, 小林和人, 穂積直裕, 西条芳文, 草野研吾, 大江透

循環器科　59　(3)　303　2006/03/28

ISSN：0388-1911
生体組織用超音波顕微鏡のためのエコー成分推定法

田中直彦, 小林和人, 穂積直裕, 西条芳文, 田中元直, 大槻茂雄

超音波医学　33　(2)　256　2006/03/15

ISSN：1346-1176
FRS-093 Automatic Segmentation of IVUS Image by Self-organizing Map(Visualization of Atherosclerotic Plaque (I) FRS19,Featured Research Session (English),The 70th Anniversary Annual Scientific Meeting of the Japanese Circulation Society)

Saijo Yoshifumi, Tanaka Akira, Akino Yoshihisa, Hanadate Yasushi, Yambe Tomoyuki

Circulation journal : official journal of the Japanese Circulation Society　70　136-136　2006/03/01
Publisher: Japanese Circulation Society
ISSN：1346-9843
Development of ultrasound-speed microscope for biological tissue characterization driven by nano-second pulse

KOBAYASHI Kazuto, HOZUMI Naohiro, SAIJO Yoshifumi, OHTSUKI Shigeo

The Journal of the Acoustical Society of Japan　62　(3)　148-152　2006/03/01
Publisher: 一般社団法人日本音響学会
DOI： 10.20697/jasj.62.3_148 　

ISSN：0369-4232

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医学生物学分野における超音波顕微鏡の応用として,100〜200MHzのバースト波を用い組織試料の表裏面からの反射の干渉を利用した組織音響特性(音速・減衰)の計測法が提案されていたが,計測時間短縮や装置の小型化の要求があった。我々は広帯域のパルス波を用いた計測法を提案し,効率的な測定を行うことを可能とした。実用化にあたり装置の高速化のために機械走査と測定信号転送方法を検討しパーソナルコンピュータとマイコン,専用回路を組み合わせ,それぞれが持つ特長を最大限に生かしたハイパフォーマンスなシステムを構築した。
In vivo Observation for Biological Tissue by Acoustic Impedance Microscope

KIMURA, TERAUCHI S, MURAKAMI Y, HOZUMI N, NAGAO M, YOSHIDA S, KOBAYASHI K, SAIJO Y

IEICE technical report　105　(553)　25-29　2006/01/19
Publisher: 一般社団法人電子情報通信学会
ISSN：0913-5685

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We have proposed a new method for two-dimensional acoustic impedance imaging for biological tissue that can perform micro-scale observation without preparing a sliced specimen. A tissue was attached on a plastic plate of 0.5 mm in thickness. An acoustic pulse with a frequency range up to 100 MHz was transmitted from the "rear side" of the plate, the acoustic beam being focused at the boundary between the tissue and plate. The reflection intensity was interpreted into local acoustic impedance of the target tissue. An acoustic impedance microscopy with 200 x 200 pixels, its view port being 2 x 2 mm, was obtained by mechanically scanning the transducer. Quantification of acoustic impedance was performed using water or an appropriate material as a reference. The accuracy was assessed by using salt water. As for an observation, a rat cerebellum was employed. The development of parallel fiber in cerebella cultures was clearly observed as the contrast in acoustic impedance. The proposed technique is believed to be a powerful tool for biological tissue characterization, as neither staining nor slicing is required.
223 Effect of Anisotropic Feedback Points Arrangement in Three-dimensional Ultrasonic-Measurement-Integrated Simulation

FUNAMOTO Kenichi, HAYASE Toshiyuki, SAIJO Yoshifumi, YAMBE Tomoyuki

2005　(18)　105-106　2006/01/12
Publisher: The Japan Society of Mechanical Engineers
経食道心エコーによる左室補助装置装着患者の心機能評価

西條芳文, 齋木佳克, 井口篤志, 田林晄一, 白石泰之, 関根一光, 山家智之

日本生体医工学会大会プログラム・論文集　45th　2006

ISSN：1347-443X
左心補助装置装着症例の術中経食道心エコー所見

西條芳文, 齋木佳克, 井口篤志, 田林晄一, 白石泰之, 関根一光, 山家智之

日本心エコー図学会学術集会抄録集　17th　2006
特集 DES時代のBeyond Angiography Virtual Histologyの基礎． (Coronary Intervention )

Saijo Yoshifumi

Coronary Intervention　2　(1)　82-87　2006/01
Fundamental Study on the Development of a Diagnostic System for Left Ventricular Plastic Surgery of the Abscission Area

UEMATSU Miyuki, SHIRAISHI Yasuyuki, SEKINE Kazumitsu, YAMBE Tomoyuki, SAIJO Yoshifumi, ANDO Hayato, PARK Young-Kwang, TAKEDA Sunao, IWASAKI Kiyotaka, UMEZU Mitsuo

Transactions of the Japanese Society for Medical and Biological Engineering : BME　43　(4)　653-660　2005/12/10
Publisher: Japanese Society for Medical and Biological Engineering
ISSN：1347-443X

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Ventricular aneurysm is one of the complications that follow a myocardial infarction. Left ventricular (LV) plastic and reconstructive surgery, Dor procedure, is widely performed in order to improve patients' cardiac functions. However, it is anticipated that the abscission region of the ventricle might cause some complications, such as mitral valve regurgitation. Therefore, the decision of what to be done with that area might affect therapeutic consequences. In this study, the authors have developed a measurement system for surface movement and a display system to demonstrate decreased LV systolic function during surgery. This system is capable of evaluating the cardiac function using displacement data obtained from superficial motion of the specific regions. Prior to measurement, the reflective ball markers were sutured on the surface of the heart without any complications or infarctions. The point of the markers indicated the anatomically specific points, such as apex, septum, mitral valve, and papillary muscles. The location of points was sequentially measured by an optical three-dimensional location sensor. The superficial area of the left ventricle from the left thoracotomy view was divided into 12 triangular regions each composed of three markers. As the contraction of the regional area corresponds to the cardiac systolic function, the changes in each area were examined. The contraction rate of the heart was superimposed onto the video images of a natural heart, which were obtained simultaneously. An animal study was performed to compare heart functions under a normal pulsating state and during the time of a myocardial infarction. The physical data such as electrocardiogram, blood flow and pressure were simultaneously obtained and compared using this approach. With the physical data, it was confirmed that strain change in the regional area was coincident with a contraction of the actual heart. It was also found that this method is simple enough to set up in the operation theater. In the near future, this method will contribute widely to the clinical diagnoses of patients, when advanced surgery such as robot surgery and/or organ transplant become popular.
B117 Development of a totally-implantable artificial myocardium using a shape memory alloy fiber

NAGATOSHI Jun, ITOH Shinji, UEMATSU Miyuki, TANAKA Takashi, UMEZU Mitsuo, SHIRAISHI Yasuyuki, SEKINE Kazumitsu, KONNO Satoshi, SAIJO Yoshifumi, YAMBE Tomoyuki, TANAKA Akira, YOSHIZAWA Makoto, MASUMOTO Noriyasu, FUJIMOTO Tetsuo, HOMMA Dai

Proceedings of the ... JSME Conference on Frontiers in Bioengineering　2005　(16)　77-78　2005/11/08
Publisher: The Japan Society of Mechanical Engineers
ISSN：1348-2939
B205 Blood Flow Simulation Integrated with Ultrasonic Measurement : 5^<th> Report: Reproduction of Three-dimensional Unsteady Blood Flow Field

FUNAMOTO Kenichi, HAYASE Toshiyuki, SAIJO Yoshifumi, YAMBE Tomoyuki

Proceedings of the ... JSME Conference on Frontiers in Bioengineering　2005　(16)　137-138　2005/11/08
Publisher: The Japan Society of Mechanical Engineers
ISSN：1348-2939
907 Evaluation of Effectiveness of Feedback Formulae in Three-dimensional Ultrasonic-Measurement-Integrated Simulation of Blood Flow

Funamoto Kenichi, Hayase Toshiyuki, Saijo Yoshifumi, Yambe Tomoyuki

Fluids engineering conference ...　2005　139-139　2005/10/28
Publisher: The Japan Society of Mechanical Engineers
ISSN：1348-2882
A New Method for the Evaluation of the Heart Function by Surface Measurement

UEMATSU Miyuki, SHIRAISHI Yasuyuki, SEKINE Kazumitsu, YAMBE Tomoyuki, SAIJO Yoshifumi, MUTO Shunsuke, PARK Young-Gang, ANDO Hayato, MATSUMOTO Toru, TAKEDA Sunao, IWASAKI Kiyotaka, UMEZU Mitsuo, UCHIYAMA Akihiko

2005　(1)　23-26　2005/07/19
Estimation of echo component in sound speed microscopy for biological tissue

TANAKA Naohiko, KOBAYASHI Kazuto, HOZUMI Naohiro, SAIJO Yoshifumi, TANAKA Motonao, OHTSUKI Shigeo

IEICE technical report. Ultrasonics　105　(135)　21-26　2005/06/17
Publisher: 一般社団法人電子情報通信学会
ISSN：0913-5685

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Ultrasonic sound speed microscopy is a useful tool for tissue characterization. The sound speed of sliced tissue sample is determined by the propagation delay time of the echoes reflected at the front and rear surfaces of tissue sample. In practice there is a difficulty that these echoes overlap each other, and unnecessary echoes which is caused by multiple reflection are also overlapped. This paper propose an estimation technique of multiple echo component for the determination of sound speed. The proposed technique is applied to the measurement data obtained by the ultrasonic microscopy using 80MHz transmission pulse, and the performance of echo estimation is confirmed.
ALTERNATIVE MAGNETIC STIMULATION ON PERIPHERAL CIRCULATION FOR REGENERATIVE MEDICINE

YAMBE T., SEKINE K., SHIRAISHI Y., SAIJO Y, KONNO S., MARUYAMA M., NITTA S, TABAYASHI K., INOUE A

25　(1)　10-10　2005/06/10

ISSN：0916-6238
医学用超音波音速顕微鏡の開発とその世界的展開

西条芳文, 穂積直裕, 小林和人, 田中直彦, 福間功史, 佐々木英彦, 田中元直, 山家智之

生体医工学　43　(2)　329　2005/06/10

ISSN：1347-443X
11. 医学用超音波音速顕微鏡の開発とその世界的展開(平成16年度東北支部大会抄録, 支部大会抄録)

西條芳文, 穂積直裕, 小林和人, 田中直彦, 福間功史, 佐々木英彦, 田中元直, 山家智之

生体医工学 : 日本エム・イー学会誌　43　(2)　2005/06/10
Publisher: 社団法人日本生体医工学会
ISSN：1347-443X
血管内超音波(IVUS)の画像解析(3.2 第3回情報シナジー研究会, 3. 研究活動)

田中明, 西條芳文, エスメラルドドスサントスフィロ, 岩本貴宏, 阿部健一, 吉澤誠

年報　4　79-82　2005/05
Publisher: 東北大学情報シナジーセンター
Estimation of sound speed for ultrasonic microscopy

TANAKA Naohiko, KOBAYASHI Kazuto, HOZUMI Naohiro, SAIJO Yoshifumi, OHTSUKI Shigeo

Japanese journal of medical ultrasonics = 超音波医学　32　S303　2005/04/15

ISSN：1346-1176
Comparison of Ultrasonic Sound Speed among Several Stage of Myocardial Degeneration

NAKAMURA Yoichi, KOBAYASHI Kazuto, HOZUMI Naohiro, SAIJO Yoshifumi

Japanese journal of medical ultrasonics = 超音波医学　32　S365　2005/04/15

ISSN：1346-1176
Intravascular Two-dimensional Tissue Velocity Imaging of Vulnerable Plaque(Intravascular Endoscopy/Intravascular Ultrasound 4 (I), The 69th Annual Scientific Meeting of the Japanese Circulation Society)

Saijo Yoshifumi, Tanaka Akira, Hirosaka Akira, Yoshizawa Makoto, Akino Yoshihisa, Yambe Tomoyuki

Circulation journal : official journal of the Japanese Circulation Society　69　245-246　2005/03/01
Publisher: Japanese Circulation Society
ISSN：1346-9843
Development of Speed of Sound Microscopy for Assessment of Tissue Elasticity of Coronary Artery(Echo/Doppler 8 (I), The 69th Annual Scientific Meeting of the Japanese Circulation Society)

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

Circulation journal : official journal of the Japanese Circulation Society　69　295-295　2005/03/01
Publisher: Japanese Circulation Society
ISSN：1346-9843
AM05-17-010 Effect of Feedback Points Arrangement on Accuracy of Three-dimensional Ultrasonic-Measurement-Integrated Simulation of Blood Flow

Funamoto Kenichi, Hayase Toshiyuki, Saijo Yoshifumi, Yambe Tomoyuki

2005　226-226　2005
Publisher: 日本流体力学会

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We have developed Ultrasonic-Measurement-Integrated (UMI) simulation to obtain detailed and accurate information of blood flow field numerically for the diagnosis or treatment of aneurysms. In this methodology, feedback signals derived from the difference between Doppler velocities by measurement and computation are fed back to the numerical simulation. In this study, we investigate the effect of feedback point arrangement on the computational accuracy of three-dimensional UMI simulation by numerical analysis. The result of UMI simulation converges to the standard solution in the feedback domain and in some extent of the downstream region of the feedback domain. The computational accuracy is more improved as the increment of feedback point density, while the necessary computational time for convergence is unchanged.
Comparison of Brachial-Ankle Pulse Wave Velocity in Japanese and Russians

LIU HONGJIAN, YAMBE TOMOYUKI, ZHANG XIUMIN, SAIJO YOSHIFUMI, SHIRAISHI YASUYUKI, SEKINE KAZUMITSU, MARUYAMA MITSUYA, KOVALEV YURI A., MILYAGINA IRINA A., MILYAGIN VIKTOR A., NITTA SHINICHI

Tohoku J. Exp. Med.　207　(4)　263-270　2005
Publisher: Tohoku University Medical Press
DOI： 10.1620/tjem.207.263 　

ISSN：0040-8727 1349-3329

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Pulse wave velocity (PWV) is a well-known indicator of arterial stiffness and a marker of the presence of vascular lesions. Cardiovascular mortality in Russia has become the highest in the world. The Japanese are enjoying long lives, and the mortality caused by cardiovascular diseases has thus far remained at lower levels than that in Russia. In this study, we focused on brachial-ankle pulse wave velocity (baPWV) obtained from normal human subjects in Russia as well as in Japan, and compared their respective cardiovascular risks. We evaluated baPWV in 337 Japanese and 138 Russian healthy subjects. The baPWV was recorded using a PWV diagnosis device. BaPWV was measured between 2 locations of the arterial tree. The baPWV in the Russian group was significantly higher than that obtained in the Japanese of two groups categorized by age (40-59 years and 60- years). Further, body mass index (BMI), systolic blood pressure (SBP) and diastolic blood pressure in the Russian group were significantly higher than those obtained in Japanese in three age groups (under 39 years, 40-59 years, and 60- years). Moreover, the baPWV indicated a positive correlation with age, BMI and SBP in both Japanese and Russians, although the increasing trend of the baPWV against age of the Russian group had a larger value than that of the Japanese. Therefore, we suggest that arterial stiffness might be promoted earlier in the Russian group, which might be the main cause of the increased cardiovascular risk in Russia.
Blood Flow Simulation Integrated with Ultrasonic Measurement 3^<rd> Report : Reproduction of Three-dimensional Blood Flow Field

FUNAMOTO Kenichi, HAYASE Toshiyuki, SAIJO Yoshifumi, YAMBE Tomoyuki

Proceedings of the ... JSME Conference on Frontiers in Bioengineering　2004　(15)　113-114　2004/11/04
Publisher: The Japan Society of Mechanical Engineers
ISSN：1348-2939
Development of Echo-dynamography (Blood Flow Analysis by Acceleration Distribution Method)

SUGAWARA Shigeo, TANAKA Motonao, YAMAGUCHI Tasuku, YAMANAKA Tamon, MIBIKI Yoshiaki, KATAHIRA Yoshiaki, NAKAJIMA Hiroyuki, OHTUKI Shigeo, SAIJO Yoshifumi

31　S167　2004/04/15

ISSN：1346-1176
Development of Echo-Dynamography

NAKAJIMA Hiroyuki, TANAKA Motonao, SUGAWARA Shigeo, YAMAGUCHI Tasuku, YAMANAKA Tamon, MIBIKI Yoshiaki, KATAHIRA Yoshiaki, OHTUKI Shigeo, SAIJO Yoshifumi

31　S168　2004/04/15

ISSN：1346-1176
Two-dimensional tissue velocity distribution of coronary artery by intravascular ultrasound

SAIJO Yoshifumi, TANAKA Akira, IWAMOTO Takahiro, SANTOS FILHO Dos Esmeraldo, YOSHIZAWA Makoto

Journal of medical ultrasonics = 超音波医学　31　S166　2004/04/15

DOI： 10.1016/j.ultras.2003.11.022 　

ISSN：1346-1176
Medical application of scanning acoustic microscopy for sound speed measurement

SAIJO Yoshifumi, KOBAYASHI Kazuto, SASAKI Hidehiko, FUKUMA Koushi, HOZUMI Naohiro, TANAKA Naohiko

Journal of medical ultrasonics = 超音波医学　31　S121　2004/04/15

ISSN：1346-1176
Ultrasonic-Measurement-Integrated Simulation for Blood Flows 2^<nd> Report : Reproduction of Blood Flow in Aorta

FUNAMOTO Kenichi, HAYASE Toshiyuki, SHIRAI Atsushi, YAMBE Tomoyuki, SAIJO Yoshifumi

2004　(16)　165-166　2004/01/21
Publisher: The Japan Society of Mechanical Engineers
家兎棘上筋腱骨付着部の物理特性超音波顕微鏡を用いた計測

佐野博高, 西條芳文

肩関節　28　(2)　209-213　2004

DOI： 10.11296/katakansetsu1977.28.2_209 　
B324 Study of Feedback Law for Ultrasonic-Measurement-Integrated Simulation of Blood Flow

FUNAMOTO Kenichi, HAYASE Toshiyuki, SHIRAI Atsushi, SAIJO Yoshifumi, YAMBE Tomoyuki

2004　538-539　2004
Publisher: 日本流体力学会

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In order to reproduce the blood velocity and pressure fields of the blood flow for an accurate diagnosis or treatment for serious circulatory diseases such as aortic aneurysms, we integrate color Doppler ultrasonography and numerical simulation. We term this method as Ultrasonic-Measurement-Integrated (UMI) simulation. In the UMI simulation, feedback signals are added to the governing equations to compensate for the difference between computation and measurement. In this paper, we investigate effects of feedback law of the UMI simulation, such as feedback formulae, number and arrangement of monitoring points and the direction of ultrasonic beam for acquisition of Doppler velocity data, on the accuracy of the UMI simulation and computational time. It is revealed that the result of UMI simulation in the feedback domain rapidly converges to the standard solution, even with inevitably incorrect upstream boundary conditions.
新しい人工心筋システムの開発

白石泰之, 山家智之, 関根一光, 西條芳文, 渡邉誠, 柴田宗一, 山口済, 王慶田, 段旭東, 劉紅箭, 仁田新一, 岡本英治, 吉澤誠, 田中明, 小川大祐, 佐藤文博, 松木英敏, 川野聡恭, 羅雲, 堀義生, 田林晄一, 高木敏行, 早瀬敏幸, 圓山重直, 佐々田比呂志, 梅津光生, 本間大

日本AEM学会誌　12　(2)　87-93　2004
パルス励起型超音波音速顕微鏡=FFT超音波音速顕微鏡=

小林和人, 穂積直裕, 西条芳文

超音波Techno　15　(6)　101-105　2003/11

ISSN：0916-2410
Influence of Hypertension on Cardiac Function Examined by Echocardiography

WATANABE Sachiko, SUZUKI Namiko, SUZUKI Tomoyuki, KUDO Atsuko, GOTOH Yuriko, SAIJO Yoshifumi

52　(6)　795-800　2003/06/25

ISSN：0915-8669
パルス波を用いる超音波顕微鏡のための組織音速推定法

田中直彦, 小林和人, 穂積直裕, 西条芳文, 田中元直, 大槻茂雄

超音波医学　30　S149　2003/04/15

ISSN：1346-1176
パルス励起型超音波音速顕微鏡

小林和人, 根本由記子, 穂積直裕, 西条芳文, 田中元直, 田中直彦, 大槻茂雄

超音波医学　30　S146　2003/04/15

ISSN：1346-1176
FFT超音波顕微鏡による心移植モデルの音響特性計測

西条芳文, 佐々木英彦, 宮川利史, 穂積直裕, 小林和人, 大槻茂雄, 田中直彦, 田中元直, 仁田新一

超音波医学　30　S175　2003/04/15

ISSN：1346-1176
Tissue Characterization of Cardiovascular Tissues by High Frequency Ultrasound

SAIJO Yoshifumi

21　(2)　101-105　2003/03/25

ISSN：0288-450X
Acoustic microscopy(Special Issue on Ultrasound Technology)

SAIJO Yoshifumi, Yoshifumi SAIJO

11　(1)　8-11　2003/03/10
Publisher: 日本AEM学会
ISSN：0919-4452
Development of a Pocket-Size Ultrasound Device Connected to the USB Port

Saijo Yoshifumi, Kobayashi Kazuto, Arai Hitoshi, Nemoto Yukiko, Nitta Shin-ichi

Circulation journal : official journal of the Japanese Circulation Society　67　346-346　2003/03/01
Publisher: Japanese Circulation Society
ISSN：1346-9843
Intravascular Tissue Velocity Imaging

Saijo Yoshifumi, Tanaka Akira, Owada Naoki, Akino Yoshihisa, Nitta Shin-ichi

Circulation journal : official journal of the Japanese Circulation Society　67　349-349　2003/03/01
Publisher: Japanese Circulation Society
ISSN：1346-9843
Ultrasonic-Measurement-Integrated Simulation for Blood Flows : 1^<st> Report : Reduction of Error Originating from Upstream Boundary Condition

FUNAMOTO Kenichi, HAYASE Toshiyuki, SHIRAI Atsushi, YAMBE Tomoyuki, SAIJO Yoshifumi

Proceedings of the ... JSME Conference on Frontiers in Bioengineering　1　83-84　2003
Publisher: The Japan Society of Mechanical Engineers
ISSN：1348-2939
Motion Analysis of Arterial Wall Using Itravascular Ultrasound (IVUS) Image

TANAKA Akira, YOSHIZAWA Makoto, ABE Ken-ichi, SAIJO Yoshifumi, NITTA Shin-ichi

17　47-48　2002/09/09
高周波数超音波による心血管系の組織診断

西条芳文, 田中元直, 仁田新一, 金井浩, 小林和人, 穂積直裕

超音波医学　29　S188　2002/05/15

ISSN：1346-1176
痴呆モデルマウスにおける脳組織変性の音響特性

西条芳文, 高井俊行, 海部知則, 菅原章子, 小林和人, 穂積直裕, 田中元直, 仁田新一

超音波医学　29　S236　2002/05/15

ISSN：1346-1176
Application of acoustic microscopy to assessment of cardiovascular biomechanics. (J Acoust Soc Am)

Saijo Y, Sasaki H, Nitta S, Tanaka M, Joergensen CS, Falk E

J Acoust Soc Am　112　(5)　2209　2002/04
Differentiation of type I and III collagen in carotid plaques by high frequency ultrasound

Saijo Yoshifumi, Nitta Shin-ichi, Jorgensen Claus

Circulation journal : official journal of the Japanese Circulation Society　66　208-208　2002/03/31
Publisher: Japanese Circulation Society
ISSN：1346-9843
Influence of Aging on Cardiac Function Examined by Echocardiography

WATANABE Sachiko, SUZUKI Namiko, KUDO Atuko, SUZUKI Tomoyuki, OHUCHI Mieko, GOTOH Yuriko, SAIJO Yoshifumi, MURAYAMA Nobuki

29　(2)　J145-J151　2002/03/15

ISSN：1346-1176
Single-Beat Estimation of E_<max> Based on Both Linearity of Ventricular Elastance and Constancy of Ventricular Dead Volume

YOSHIZAWA Makoto, YOKOGAWA Megumi, TANAKA Akira, ABE Ken-ichi, SAIJO Yoshifumi, YAMBE Tomoyuki, NITTA Shin-ichi, KASS David A.

16　45-48　2001/08/29
Noninvasive Estimation of E_<max> Based on Aortic Flow Automatically Extracted from Doppler Echocardiography

HIKOSAKA Takahiro, YOSHIZAWA Makoto, TANAKA Akira, ABE Ken-ichi, SAIJO Yoshifumi, YAMBE Tomoyuki, NITTA Shin-ichi

16　49-52　2001/08/29
Efficiency of intraoperative transesophageal echocardiography for lung transplantation

SAIJO Y., OKADA Y., MATSUMURA Y., KONDO T., NITTA S.

28　(3)　J464　2001/04/15

ISSN：1346-1176
Scanning acoustic microscopy with GHz frequency ultrasound for biomedical use

SAIJO Y., SASAKI H., NITTA S., TANAKA M., KOBAYASHI K.

28　(3)　J394　2001/04/15

ISSN：1346-1176
Evaluation of left ventricular function in the congestive heart failure by using Doppler-pressure

SUGAWARA S., KATAHIRA Y., NITTA K., TANAKA M., NAKAJIMA H., NITTA S., SAIJO Y., OHTSUKI S.

28　(3)　J374　2001/04/15

ISSN：1346-1176
A Noninvasive Estimation Tool for Cardiac Function (E_<max> and PVA)

YOSHIZAWA Makoto, HIKOSAKA Takahiro, TANAKA Akira, ABE Ken-ichi, SAIJO Yoshifumi, YAMBE Tomoyuki, NITTA Shin-ichi, KASS David A.

15　189-192　2000/10/13
Noninvasive Estimation of Left Ventricular Pressure Waveform

KAWAGISHI Takefumi, YOSHIZAWA Makoto, TANAKA Akira, ABE Ken-ichi, SAIJO Yosifumi, YAMBE Tomoyuki, NITTA Shin-ichi

15　185-188　2000/10/13
高周波振動流が下半身血管インピーダンスへ与える影響

許立慶, 山家智之, 西條芳文

加齢医学研究所雑誌　51　(3)　121-130　2000/07
Publisher: 東北大学加齢医学研究所研究会
ISSN：1340-3397
Microscopy. (Ultrasound Med Biol)

Saijo Y, Chubachi N

Ultrasound Med Biol　26 Suppl 1　S30-2　2000/05
Medical Ultrasonics in 21^<st> Century-Ultrasonic Communication with Cells-

SAIJO Y.

27　(4)　739-739　2000/04/15

ISSN：1346-1176
Quantitative analysis of the vortex by the Flow-Function-Method

SUGAWARA S., KATAHIRA Y., NITTA K., TANAKA M., NAKAJIMA H., NITTA S., SAIJO Y., OHTSUKI S.

27　(4)　703-703　2000/04/15

ISSN：1346-1176
The application of scanning acoustic microscopy to borderline cases of tumor pathology

SASAKI H., SAIJO Y., TERASAWA Y., OKAWAI H., NITTA S., TANAKA M.

26　(4)　345-345　1999/04/15

ISSN：1346-1176
Thickness-distribution Estimation in Tissue Characterization by Using the Acoustic Microscopy

OGURA Nobuhiko, SAIJO Yoshifumi, TANAKA Naohiko, OHTSUKI Shigeo

1998　(2)　1165-1166　1998/09/01

ISSN：1340-3168
超音波顕微鏡の生体組織に対する応用 (8月第1土曜特集バイオイメ-ジング--基礎と臨床の最前線)

仁田新一, 西条芳文

医学のあゆみ　186　(5)　353-357　1998/08/01
Publisher: 医歯薬出版
ISSN：0039-2359
Analysis of Small Vibration on the Surface of Tissue Exposed to Ultrasound

SAIJO Y., SATO K., KANAI H., NITTA S., TANAKA M.

25　(4)　504-504　1998/04/15

ISSN：1346-1176
Characterization of Renal Cell carcinoma By Scanning Acoustic Microscopy, Optical Microscopy, and Electron Microscopy

SASAKI H., SAIJO Y., TERASAWA Y., OKAWAI H., NITTA S., TANAKA M.

25　(4)　362-362　1998/04/15

ISSN：1346-1176
15)超音波画像の成り立ちの観点による心臓断層像の解釈

大川井宏明, 仁田新一, 山家智之, 西條芳文, 佐々木英彦

Japanese circulation journal　61　778-778　1998/03/20
Publisher: 社団法人日本循環器学会
ISSN：0047-1828
Recent Progress in Artificial Organ Research at Tohoku University

Tomoyuki Yambe, Makoto Yoshizawa, Akira Tanaka, Ken-ichi Abe, Satoyuki Kawano, Hidetoshi Matsuki, Shigenao Maruyama, Shintaro Amae, Naoshi Wada, Takamichi Kamiyama, Toshiyuki Takagi, Yun Luo, Junko Hayashi, Yuri A.Kovalev, Dan X.D.Sha, Shunsuke Nanka, Yoshifumi Saijo, Yoshiyuki Mibiki, Mune-ichi Shibata, Shin-ichi Nitta

Art. Organs　27　2-7　1998

DOI： 10.1046/j.1525-1594.2003.07181.x 　
Explanation of the echo from the oblique surface from a standpoint of echography.

OKAWAI H., SAIJO Y., YAMBE T., OSAWA H., SASAKI H., SHU L., NITTA K.

24　(9)　358-358　1997/09/15

ISSN：1346-1176
Influence of fat component in the tissue on the high-frequency acoustic properties by scanning acoustic microscopy.

SASAKI H., SAIJO Y., OKAWAI H., NITTA S., TERASAWA Y., TANAKA M.

24　(9)　430-430　1997/09/15

ISSN：1346-1176
Information entropy of the left ventricular contraction and its clinical significance

YAMBE T., NANKA S., OKAWAI H., SAIJO Y., NITTA S.

24　(9)　409-409　1997/09/15

ISSN：1346-1176
Sound Speed Measurement of Cultured Cells by Ultrasonic Spectroscopy.

SAIJO Y., SASAKI H., OKAWAI H., NITTA S., TANAKA M.

24　(9)　423-423　1997/09/15

ISSN：1346-1176
Ultrasonic Properties of Thin Specimens Determined by Acoustic Microscopy.

SAIJO Y., SASAKI H., OKAWAI H., NITTA S., TANAKA M.

24　(9)　150-150　1997/09/15

ISSN：1346-1176
Visualization of Brain Tissue by Acoustic Microscopy.

SAIJO Y., HORIMOTO N., SASAKI H., OKAWAI H., NITTA S., TANAKA M.

24　(9)　167-167　1997/09/15
Publisher: 東洋出版
ISSN：1346-1176
Application of scanning acoustic microscopy to the diseased kidney with renal cell carcinoma

SASAKI H., SAIJO Y., NITTA S., TERASAWA Y., OKAWAI H., TANAKA M.

24　(3)　621-621　1997/03/15

ISSN：1346-1176
Explanation of the echo from epicardium of posterior wall in the echocardiography

OKAWAI H., NITTA S., YAMBE T., SAIJO Y., SASAKI H., SHU L.

24　(3)　474-474　1997/03/15

ISSN：1346-1176
Measurement of Thickness of Biological Specimens by Ultrasonic Spectroscopy

SAIJO Y., SASAKI H., OKAWAI H., NITTA S., TANAKA M.

24　(3)　562-562　1997/03/15

ISSN：1346-1176
Acoustic Properties of the Normal and Pathologic Myocardium by Scanning Acoustic Microscopy

SAIJO Yoshifumi, SASAKI Hidehiko, OKAWAI Hiroaki, NAGANUMA TORU, TANAKA Motonao

Jpn J Med Ultrasonics　22　(11)　787-798　1995/11/15

ISSN：0287-0592
27)冠動脈楔入圧の検討(第3報) : 慢性閉塞病変における検討(日本循環器学会第113回東北地方会)

菊地雄一, 目黒泰一郎, 遠藤閑夫, 大友達志, 和田有行, 南家俊介, 寺沢良夫, 武田久尚, 高橋和彦, 柿沼義人, 井筒憲司, 山家智之, 西條芳文, 永沼徹, 小林信一

Japanese circulation journal　59　605-605　1995/06/20
Publisher: 社団法人日本循環器学会
ISSN：0047-1828
10)KSエントロピーの計測による左室収縮時系列曲線におけるカオス的ダイナミクスの検出(日本循環器学会第113回東北地方会)

山家智之, 仁田新一, 高橋和彦, 西條芳文, 永沼滋, 小林信一, 柿沼義人, 秋保洋, 南家俊介, 大沢上, 永沼徹, 田中元直, 福寿赳雄, 三浦誠, 内田直樹, 田林晄一, 阿部健一, 吉沢誠, 高安秀樹

Japanese circulation journal　59　603-603　1995/06/20
Publisher: 社団法人日本循環器学会
ISSN：0047-1828
超音波顕微鏡の開発と医学応用

田中元直, 西条芳文

日本臨床　53　(6)　p1527-1535　1995/06
Publisher: 日本臨床社
ISSN：0047-1852
Acoustic microscopy in medicine and biology. (Proc 2nd Asian Conference on Computer Vision)

Saijo Yoshifumi, Chubachi Noriyoshi

Proc 2nd Asian Conference on Computer Vision　3　273-277　1995/04
0272 補助人工心臓は交感神経活動の情報量エントロピーを低下させる

山家智之, 南家俊介, 小林信一, 西條芳文, 仁田新一

Japanese circulation journal　59　111-111　1995/03/01
Publisher: 社団法人日本循環器学会
ISSN：0047-1828
0316 超音波顕微鏡による動脈硬化病変の定量的評価

西條芳文, 佐々木英彦, 永沼徹, 田中元直

Japanese circulation journal　59　122-122　1995/03/01
Publisher: 社団法人日本循環器学会
ISSN：0047-1828
MICRO-MEASUREMENTS OF ELASTICITY OF INFARCTED MYOCARDIUM BY A SCANNING ACOUSTIC MICROSCOPE SYSTEM

SAIJO Yoshifumi, SASAKI Hidehiko, NAGANUMA Toru, TANAKA Motonao

Japanese circulation journal　57　(7)　656-656　1993/07/20
Publisher: Japanese Circulation Society
ISSN：0047-1828
左室内における渦流の発生時期とその規模 : 口述発表 : 第57回日本循環器学会学術集会

田中元直, 高橋和彦, 西條芳文, 密岡幹夫, 千葉茂樹, 佐々木英彦, 仁田新一

Japanese circulation journal　57　70-70　1993/03/01
Publisher: 社団法人日本循環器学会
ISSN：0047-1828
超音波顕微鏡による心筋梗塞組織弾性率の微小計測 : ポスター発表 : 第57回日本循環器学会学術集会

西條芳文, 佐々木英彦, 永沼徹, 田中元直

Japanese circulation journal　57　203-203　1993/03/01
Publisher: 社団法人日本循環器学会
ISSN：0047-1828
左心補助人工心臓駆動下の交感神経活動に関する実験的研究

山家智之, 仁田新一, 片平美明, 薗部太郎, 西条芳文, 秋保洋, 永沼滋, 田中元直

Japanese circulation journal　56　1035-1035　1992/10/20
Publisher: 社団法人日本循環器学会
ISSN：0047-1828
流線分布図法による心臓腔内血流動態の解析

田中元直, 山本厚子, 佐藤ノリ子, 遠藤閑夫, 高橋和彦, 西條芳文, 仁田新一

Japanese circulation journal　56　103-103　1992/03/01
Publisher: 社団法人日本循環器学会
ISSN：0047-1828

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Books and Other Publications 22

生体組織の超音波計測

松川真美, 山口匡, 長谷川英之, ds, 西條芳文

コロナ社　2022/05

ISBN: 9784339013436
生体ひかりイメージング : 基礎と応用

星, 詳子, 山田, 幸生eds. 西條芳文

エヌ・ティー・エス　2021/12

ISBN: 9784860437299
Technological advancements in biomedicine for healthcare applications

Jinglong Wu, ed, Yoshifumi Saijo

Medical Information Science Reference　2012/10/31

ISBN: 1466621966
Ultrasonic and electromagnetic NDE for structure and material characterization : engineering and biomedical applications

Kundu, T, Tribikram) ed Yoshifumi Saijo

CRC Press　2012/06/25

ISBN: 1439836639
非侵襲・可視化技術ハンドブック

Saijo Yoshifumi

株式会社エヌティーエス　2007/06
Advanced Ultrasonic Methods for Material Characterization

Tribikram Kundu, ed. SAIJO Yoshifumi

ISTE　2007/01
冠動脈疾患プロフェッション7 冠動脈疾患のNew Concept．

SAIJO Yoshifumi

中山書店　2006/07/03
IVUSマニュアル

SAIJO Yoshifumi

中山書店　2006/06/30
State of the Art: Ultrasonics in Medicine

Kouichi Itoh, ed, Saijo Yoshifumi, Tanaka Akira, Sasaki Hidehiko, Iwamoto Takahiro, Santos Filho Esmerald, Yoshizawa Makoto, Yambe Tomoyuki

Elsevier　2004/04
Vascular Ultrasound（１）

Saijo Yoshifumi, van der Steen A.F

Springer　2003/04
Vascular Ultrasound（２）

Yoshifumi Saijo, A.F.W. van der, Steen ed, Saijo Yoshifumi

Springer　2003/04
Ultrasonic Methods for Material Characterization

Dominique Placko, Tribikram Kundu, ed, Saijo Yoshifumi

Lavosier　2003/04
Ultrasonic Nondestructive Evaluation: Engineering and Biological Material Characterization

Tribikram Kundu, ed, Saijo Yoshifumi

CRC Press　2003/04
Acoustical Imaging Vol. 26

Roman Gr. Maev, ed, Saijo Yoshifumi, Iguchi Atsushi, Tabayashi Koichi, Kobayashi Kazuto, Sasaki Hidehiko, Tanaka Akira, Hozumi Naohiro, Nitta Schin-ichi

Plenum Publishing Corporations /Kluwer Academic Publishers　2002/04
Acoustical Imaging. Vol. 24

Hua Lee ed, Saijo Yoshifumi, Sasaki Hidehiko, Okawai Hiroaki, Kataoka Noriyuki, Sato Masaaki, Nitta Schin-ichi, Tanaka Motonao

Plenum Publishing Corporations /Kluwer Academic Publishers　2000/04
Acoustical Imaging Vol. 23

Sidney Lees, and Leonard, A. Ferrari, ed, Saijo Yoshifumi, Sasaki Hidehiko, Okawai Hiroaki, Nitta Shin-ichi, Tanaka Motonao

Plenum Publishing Corporations　1997/04
Ultrasonic Tissue Characterization（２）

Dunn F Tanaka, M, Ohtsuki S, Saijo Y, ed, Saijo Yoshifumi, Sasaki Hidehiko

Springer　1996/04
Ultrasonic Tissue Characterization（１）

Dunn Floyd, Tanaka Motonao, Ohtsuki Shigeo, Saijo Yoshifumi

Springer　1996/04
Acoustical Imaging Vol. 21

Joie Pierce Jones, ed, Saijo Yoshifumi, Okawai Hiroaki, Sasaki Hidehiko, Naganuma Toru, Tanaka Motonao

Plenum Publishing Corporations　1995/04
Acoustical Imaging Vol. 22（２）

Piero Tortoli, Leonar, Masotti ed, Saijo Yoshifumi, Sasaki Hidehiko, Okawai Hiroaki, Tanaka Motonao

Plenum Publishing Corporations　1995/04
Acoustical Imaging Vol. 22（１）

Piero Tortoli, Leonar, Masotti ed, Sasaki Hidehiko, Saijo Yoshifumi, Okawai Hiroaki, Terasawa Yoshio, Nitta Shin-ichi, Tanaka Motonao

Plenum Publishing Corporations　1995/04
Acoustical Imaging. Vol. 25

Michael Halliwell, Peter N. T. Wells ed, Saijo Yoshifumi, Jorgensen Claus S, Falk Erling

Plenum Publishing Corporations /Kluwer Academic Publishers　1995/04

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Presentations 70

Main flow axis line deduced from blood flow vector distribution reflects local and whole left ventricular diastolic function. International-presentation

Nakajima H, Tabuchi H, Sugawara S, Kameyama T, Ohtsuki S, Tanaka M, Saijo Y

13th Annual Meeting of the European Association of Echocardiography in Cooperation with the Working Group on Echocardiography of the Spanish Society of Cardiology　2009/12/09
Biomedical applications of acoustic microscopy. International-presentation

2009 IEEE International Ultrasonics Symposium　2009/09/20
Acoustic microscopy – Beyond high resolution imaging. International-presentation

2009 IEEE International Ultrasonics Symposium　2009/09/20
高周波超音波イメージング用配向制御圧電結晶膜トランスデューサの開発

石河睦生, 榮西弘, 長谷川智仁, 森田剛, 西條芳文, 黒澤実, 舟窪浩

日本音響学会2009年秋季研究発表会　2009/09/15
Visualization of microstructure of the skin by 3D ultrasound microscope. International-presentation

Saijo Y, Kobayashi K, Hozumi N, Tanaka A

12th World Congress of the World Federation for Ultrasound in Medicine and Biology　2009/08/30
流軸線上速度分布による定量的心機能評価法の検討（第二報）

中島博行, 田中元直, 菅原重生, 片平美明, 亀山剛義, 大槻茂雄, 西條芳文

日本超音波医学会第82回学術集会　2009/05/24
パラフィン包埋標本作成過程において組織音速に影響を及ぼす因子の検討

中村陽一, 小林和人, 中村一文, 草野研吾, 穂積直裕, 吉田祥子, 鈴木誠, 西條芳文

日本超音波医学会第82回学術集会　2009/05/22
生体組織の固有音響インピーダンスを評価するための簡易計測プローブの提案

小林和人, 森屋健司, 穂積直裕, 西條芳文

日本超音波医学会第82回学術集会　2009/05/22
三次元高周波数超音波イメージングによる皮膚組織の微細構造の観察

西條芳文, 小林和人, 田中明, 穂積直裕

日本超音波医学会第82回学術集会　2009/05/22
低価格携帯型エコー装置の災害時エコノミークラス症候群検診への応用

西條芳文, 柴田宗一, 榛沢和彦, 小泉勝

日本超音波医学会第82回学術集会　2009/05/22
岩手宮城内陸地震における避難環境と深部静脈血栓症（DVT）

榛沢和彦, 柴田宗一, 西條芳文

日本超音波医学会第82回学術集会　2009/05/22
健診での普及を目指したポータブル超音波システムの開発

西條芳文, 小林和人, 岡田長也, 石黒稔道

第48回日本生体医工学会大会　2009/04/24
ポータブル超音波システムの健診への応用．

西條芳文, 小林和人

第20回日本心エコー図学会学術集会　2009/04/23
流軸線上速度勾配測定法による左室拡張能評価―Echo-Dynamographyによる解析．

中島博行, 田中元直, 菅原重生, 片平美明, 亀山剛義, 大槻茂雄, 西條芳文

第20回日本心エコー図学会学術集会　2009/04/23
Tissue deformation imagingによる心筋収縮dyssynchronyの評価

西條芳文, 中島博行, 菅原重生, 田淵晴名, 田中明

第20回日本心エコー図学会学術集会　2009/04/23
コイル状形状記憶合金を応用した消化管蠕動運動アクチュエータの耐久性に関する検討．

関根一光, 山家智之, 白石泰之, 西條芳文, 佐藤文博, 松木英敏, 前田剛, 中澤文雄, 淺岡憲三

第48回日本生体医工学会大会　2009/04/23
高周波数超音波イメージングによる骨・軟骨複合体組織の観察

萩原嘉廣, 安藤晃, 西條芳文

第48回日本生体医工学会大会　2009/04/23
Multimode ultrasound microscope for biomedical applications. International-presentation

2009 American Institute of Ultrasound in Medicine Annual Convention　2009/04/02
Ultrasonic tissue deformation imaging to evaluate myocardial dyssynchrony.

Saijo Y, Tanaka A

日本循環器学会第73回学術集会　2009/03/20
Visualization of micro-vessel by three-dimensional ultrasound microscope.

Saijo Y, Kobayashi K, Tanaka A

日本循環器学会第73回学術集会　2009/03/20
Visualization of microvessels in skin by three-dimensional ultrasound microscope. International-presentation

Saijo Y, Kobayashi K, Hozumi N, Tanaka A, Sakai S

30th International Symposium on Acoustical Imaging　2009/03/01
High frequency ultrasound imaging of cartilage-bone complex. International-presentation

Hagiwara Y, Saijo Y, Ando A, Kobayashi K, Tanaka A, Hozumi N, Hatori K, Itoi E

30th International Symposium on Acoustical Imaging　2009/03/01
The changes of elastic properties of periodontal ligament and mandibular condylar cartilage during development. International-presentation

Hatori K, Hagiwara Y, Saijo Y, Ando A, Ina Y, Ando K, Shiraishi N, Doi N, Suzuki Y, Sasaki K

30th International Symposium on Acoustical Imaging　2009/03/01
Biomedical Application of acoustic microscopy - Diagnosis, assessing echogenecity and biomechanics. International-presentation

Saijo Y, Hagiwara Y, Kobayashi K, Okada N, Tanaka A, Hozumi N, Tanaka M

IEEE International Ultrasonics Symposium　2008/11/01
Biomedical Application of acoustic microscopy International-presentation

IEEE International Ultrasonics Symposium　2008/11/01
音波を用いた血管の組織診断

第22回日本心血管内視鏡学会　2008/10/11
Visualization of surface and 3D morphology of skin by 100 MHz ultrasound. International-presentation

Saijo Y

6th International Conference on Ultrasonic Biomedical Microscanning　2008/09/23
医学用超音波顕微鏡の現状

日本音響学会2008年秋季研究発表会　2008/09/10
血管新生における細動脈イメージング方法の開発

第56回日本心臓病学会　2008/09/09
High frequency ultrasound imaging of surface and subsurface structures of fingerprints. International-presentation

Saijo Y, Kobayashi K, Okada N, Hozumi N, Hagiwara Y, Tanaka A, Iwamoto T

30th Annual International Conference of the IEEE Engineering in Medicine and Biology Society　2008/08/25
High frequency ultrasound characterization of artificial skin. International-presentation

Iwamoto T, Saijo Y, Hozumi N, Kobayashi K, Okada N, Tanaka A, Yoshizawa M

30th Annual International Conference of the IEEE Engineering in Medicine and Biology Society　2008/08/25
Recent progress of acoustic microscopy for medicine and biology. International-presentation

155th Meeting of the Acoustical Society of America integrated with 5th Forum Acusticum of the EAA, 2nd ASA-EAA Joint Conference　2008/06/30
Ultra-mobile echo network in health care system. International-presentation

Saijo Y, Iwamoto T, Kobayashi K, Yamaguchi S, Tsunoda H, Nakayama H, Kato N, Nemoto Y

21st IEEE International Symposium on Computer-Based Medical Systems　2008/06/18
流軸線上速度分布による定量的局所心筋機能評価法の検討－Echo-dynamographyによる流軸線分布図法の応用－

中島博行, 菅原重生, 片平美明, 田中元直, 亀山剛義, 大槻茂雄, 西條芳文

日本超音波医学会第81回学術集会　2008/05/25
高周波数超音波イメージング

日本超音波医学会第81回学術集会　2008/05/25
Three-dimensional ultrasound imaging of regenerated skin with high frequency ultrasound. International-presentation

SaijoY, Hagiwara Y, Kobayashi K, Okada N, Hozumi N, Tanaka A, Iwamoto T

5th IEEE International Symposium on Biomedical Imaging　2008/05/13
皮膚組織の3次元超音波顕微鏡像

西條芳文, 萩原嘉廣, 岩本貴宏, 小林和人, 岡田長也, 田中明, 穂積直裕, 富畑賢治

第47回日本生体医工学会大会　2008/05/10
脈波伝播速度（PWV）で測る血管の変化

第47回日本生体医工学会大会　2008/05/10
Visualization of slow flow in left atrium by optical flow method.

Saijo Y, Tanaka A

第19回日本心エコー図学会学術集会　2008/04/12
Play Station PortableTM as echo movie client.

Saijo Y, Iwamoto T, Yoshizawa M

第19回日本心エコー図学会学術集会　2008/04/12
等容収縮期の渦流形成に対する心房収縮の関与－Echodynamographyによる検討－

中島博行, 菅原重生, 片平美明, 田中元直, 亀山剛義, 大槻茂雄, 西條芳文

第19回日本心エコー図学会学術集会　2008/04/11
水熱合成ＰＺＴ多結晶膜による超小型超音波プローブの開発－超音波イメージングと分解能の検討－

長谷川智仁, 黒澤実, 石河睦生, 舟窪浩, 竹内真一, 西條芳文

日本音響学会2009年春季研究発表会　2008/03/19
超音波ずり弾性率顕微鏡の開発（その2）

炭親良, 西條芳文

日本音響学会2009年春季研究発表会　2008/03/19
B-mode and C-mode imaging of regenerated 3D skin model with 100 MHz ultrasound. International-presentation

Saijo Y, Hagiwara Y, Kobayashi K, Okada N, Tanaka A, Hozumi N, Tomihata K

2007 IEEE International Ultrasonics Symposium　2007/10/28
Precise calibration for biological acoustic impedance microscope. International-presentation

Hozumi N, Nakao A, Terauchi S, Nagao M, Yoshida S, Kobayashi K, Yamamoto S, Saijo Y

2007 IEEE International Ultrasonics Sysmposium　2007/10/28
オプティカルフロー法による心血管内血流の可視化

西條芳文, 田中明, 田林晄一, 山家智之

第55回日本心臓病学会　2007/09/11
生体内超音波ナノ・イメージング法による線維芽細胞の可視化

西條芳文, 穂積直裕, 小林和人, Santos Filho Esmeraldo

日本超音波医学会第80回学術集会　2007/05/19
生体内超音波ナノ・イメージング法の開発

西條芳文, 穂積直裕, 小林和人, Esmeraldo dos, Santos Filho

第46回日本生体医工学会大会　2007/04/26
Ultrasonic nano-imaging system for medicine and biology International-presentation

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

29th International Symposium on Acoustical Imaging　2007/04/16
Elastic Changes of Capsule in a Rat Knee Contracture Model Assessed by Scanning Acoustic Microscopy International-presentation

Yoshihiro Hagiwara, Eiichi Chimoto, Akira Ando, Yoshifumi Saijo, Eiji Itoi

29th International Symposium on Acoustical Imaging　2007/04/16
Development of Acoustic Impedance Microscope and Its Biological and Medical Applications International-presentation

Naohiro Hozumi, Satoshi Terauchi, Masayuki Nagao, Sachiko Yoshida, Kazuto Kobayashi, Seiji Yamamoto, Yoshifumi Saijo

29th International Symposium on Acoustical Imaging　2007/04/16
IVUS Attenuation Imagingによる冠動脈深部の音響特性解析

藤田雅史, 高山沙織, 塩入裕樹, 小山二郎, 堀口聡, 井上寛一, 田中明, 西條芳文

第18回日本心エコー図学会　2007/04/12
Two-dimensional Blood Flow Vector in Left Atrium Obtained by Pattern Matching International-presentation

Yoshifumi Saijo, Akira Tanaka, Yoshikatsu Saiki, Koichi Tabayashi, Tomoyuki Yambe

International Congress on Ultrasonics 2007　2007/04/09
Ultrasonic Nano-imaging of Living Cells International-presentation

Yoshifumi Saijo, Kazuto Kobayashi, Naohiro Hozumi, Esmeraldo dos, Santos Filho, Tomoyuki Yambe

International Congress on Ultrasonics 2007　2007/04/09
Visualization of Vulnerable Plaque by Multiple Parametric IVUS International-presentation

Yoshifumi Saijo, Akira Tanaka, Esmeraldo dos, Santos Filho, Takahiro Iwamoto, Shuo Li, Tomoyuki Yambe

International Congress on Ultrasonics 2007　2007/04/09
Tissue sound speed of anterior cruciate ligament in estrogen-controlled rabbits - a measurement using the scanning acoustic microscope International-presentation

Koshi Hattori, Hirotaka Sano, Yoshifumi Saijo, Eiji Itoi

International Congress on Ultrasonics 2007　2007/04/09
Coronary plaque classification with intravascular ultrasound radio-frequency signal analysis using self-organizing map International-presentation

Takahiro Iwamoto, Yoshifumi Saijo, Akira Tanaka, Esmeraldo dos, Santos Filho, Li Shuo, Makoto Yoshizawa

International Congress on Ultrasonics 2007　2007/04/09
Ultrasonic Tissue Characterization of Thrombus in Coronary Atherosclerosis International-presentation

Hidehiko Sasaki, Yoshifumi Saijo

International Congress on Ultrasonics 2007　2007/04/09
Recent Progress of Biomedical Acoustic Microscopy and Multiple Parametric IVUS Imaging at Tohoku University International-presentation

Yoshifumi Saijo

Paris-Sendai Symposium on Ultrasonic Tissue Characterization and Small Animal Imaging　2007/04/06
Development of IVUS attenuation imaging and comparison with multiple parametric imagings

Yoshifumi Saijo, Akira Tanaka, Esmeraldo dos, Santos Filho, Takahiro Iwamoto, Tomoyuki Yambe

第71回日本循環器学会学術集会　2007/03/15
Two-dimensional blood flow vector imaging of retardant flow in left atrium

Yoshifumi Saijo, Akira Tanaka, Tomoyuki Yambe

第71回日本循環器学会学術集会　2007/03/15
Twenty Years’ Development of Acoustic Microscopy for Medicine and Biology. International-presentation

Saijo Y

4th joint meeting of the Acoustical Society of America and the Acoustical Society of Japan (152nd Annual Meeting on Acoustical Society of America)　2006/11/27
Multiple Parametric IVUS Imagings for Detection of Vulnerable Plaque International-presentation

Yoshifumi Saijo, Akira Tanaka, Esmeraldo dos, Santos Filho, Tanahiro Iwamoto, Shuo Li, Makoto Yoshizawa, Tomoyuki Yambe

9th Sendai Symposium on Ultrasonic Tissue Characterization in Hawaii　2006/11/27
再生医療の評価方法としての高周波数超音波の可能性

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

第44回日本人工臓器学会大会　2006/10/31
3D acoustic microscopy for imaging of liver tissue with 100 MHz ultrasound International-presentation

Yoshifumi Saijo

5th Conference on Ultrasonic Biomedical Microscanning　2006/09/11
Evaluation of Cardiac Function of the Patients with Left Ventricular Assist Device by Transesophageal Echocardiography International-presentation

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

World Congress on Medical Physics and Biomedical Engineering 2006　2006/08/27
Development of Ultrasonic Nano-imaging System for Visualization of Cells International-presentation

Saijo Y, Hozumi N, Kobayashi K, Okada N, Lee CK, Sasaki H, Yambe T, Tanaka M

World Congress on Medical Physics and Biomedical Engineering 2006　2006/08/27
Automated Calcification Detection and Quantification in Intravascular Ultrasound Images by Adaptive Thresholding International-presentation

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

World Congress on Medical Physics and Biomedical Engineering 2006　2006/08/27
超音波による心臓・血管の中の流れの医工学的解析

西條芳文, 白石泰之, 関根一光, 山家智之, 田中元直, 田林晄一, 早瀬敏幸, 船本健一, 大槻茂雄, 菅原重生

第43回日本小児外科学会総会　2006/06/07
Automatic segmentation of IVUS image by self-organizing map

Saijo Y, Tanaka A, Akino Y, Hanadate Y, Yambe T

日本循環器学会第70回学術集会　2006/03/24

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Industrial Property Rights 3

脳組織変性の診断方法

高井俊行, 西條芳文, 菅原章子

Property Type: Patent
血流可視化診断装置

早瀬敏幸, 船本健一, 白井敦, 山家智之, 西條芳文

Property Type: Patent
超音波診断装置

西條芳文, 田中明, 坪根泉, 関水英正

第3720797号

Property Type: Patent

Research Projects 58

Biomedical imaging Competitive

1997/07 - Present
Transcranial Whole Brain Imaging by Microwave-induced Thermoacoustics

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (B)

Institution: Tohoku University

2023/04/01 - 2026/03/31
ジラジカル錯体をがん認識光熱変換プローブとするがんの未来型セラノスティクス

壹岐伸彦, 西條芳文, 高橋透, 唐島田龍之介, 権田幸祐

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 基盤研究(B)

Institution: 東北大学

2022/04/01 - 2025/03/31
Development of photoacoustic endoscope using wideband microarray for advanced intraoperative vascularity diagnosis

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (A)

2021/04/05 - 2025/03/31
Ultrasonic signed echo imaging to distinguish bwtween vulnerable and stable plaques

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (C)

Institution: Tohoku University

2021/04/01 - 2024/03/31
アーク型光音響トランスデューサーを用いた軟部肉腫反応層の評価

綿貫宗則, 西條芳文, 萩原嘉廣

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 基盤研究(C)

Institution: 東北大学

2021/04/01 - 2024/03/31

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軟部肉腫は軟部組織に発生する非上皮性悪性腫瘍であり、健常組織とともに腫瘍を摘出する広範切除術が行われる。軟部肉腫と健常組織の境界を見極めることは切除縁を決定するのに重要であるが、手術中に正確に判断するのは難しい。本研究では、ヒト指用に開発されたアーク型光音響トランスデューサーを用い、ラット脂肪組織炎症モデルおよびヒト軟部肉腫周囲の脂肪組織の光音響特性と病理組織所見を比較検討することにより、本装置の妥当性および臨床応用の可能性について検討し、最終的に軟部肉腫の術中切除縁評価が可能な3次元光音響装置開発を目指すものである。当初の計画ではラットを用いた脂肪組織炎症モデルを作成し、炎症によって変化した脂肪に適したレーザー波長の探索を行う予定であった。しかし、炎症による変化をとらえる波長を探索するよりも、肉腫モデルマウスを作成して、肉腫をとらえるのに適した波長を探索して、それを用いて肉腫の観察を行うほうが合目的と考えられ、当該年度は研究に用いる肉腫株の選定、培養条件の最適化と投与する色素の最適化の探索を行った。また、肉腫モデルマウスは、免疫不全マウスに培養細胞を注射して作成するが、細胞培養株としては骨肉腫細胞株を採用し、継代をしながら安定した培養を行うよう努めている。その骨肉腫細胞が安定して生着するには投与部位や深さ・投与量の調節が必要であり、一定期間で安定して生着できる条件の探索も行っている。
Development of 3D acoustic CT with multi-channel phonocardiogram for lung lesion detection

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Challenging Research (Exploratory)

Institution: Tohoku University

2021/07/09 - 2023/03/31
Development of transcranical four-dimensional ultrasound imaging

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

Category: Grant-in-Aid for Scientific Research (B)

Institution: Tohoku University

2020/04/01 - 2023/03/31
Basic study on high-accuracy acoustic property measurements of biological specimens by ultrasonic microscopy

ARAKAWA Mototaka

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)

Category: Grant-in-Aid for Scientific Research (C)

Institution: Tohoku University

2018/04/01 - 2021/03/31

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In this study, we proposed a robust analysis method for the acoustic properties of biological specimens measured by acoustic microscopy. To obtain the velocity and thickness of the specimen, parabolic approximation was performed to determine the frequency at which the amplitude of the normalized spectrum became maximum or minimum, considering the sound speed and thickness of the specimens and the operating frequency of the ultrasonic device used. The proposed method was demonstrated for a specimen of malignant melanoma of the skin by using acoustic microscopy attaching a concave transducer with a center frequency of 80 MHz. The variations in sound speed and thickness analyzed by the proposed method were markedly smaller than those analyzed by the method based on an autoregressive model. The proposed method is useful for the analysis of the acoustic properties of biological tissues or cells.
Development of 3D photoacoustic CT with arc tran sducer for finger joint

Saijo Yoshifumi

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

Category: Grant-in-Aid for Scientific Research (B)

Institution: Tohoku University

2017/04/01 - 2020/03/31

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Principles of 3D photoacoustic CT were investigated in order to evaluate inflammatory activity of finger joints in rheumatoid arthritis visualized with photoacoustic signal produced by strong short pulsed light. Ultrasonic sensors were semicircularly arranged to fit the shape of finger and optical fibers were inserted to pass through the light. Laser or strong LED with two different wavelengths were illuminated. Precise algorithm for calculation of the oxygen saturation was developed considering the propagation of light in biological tissue. Finally, visualization of the human finger was successfully visualized by the photoacoustic CT.
Cancer theranostics using near-infrared absorbing metal complex as a photothermal probe

Iki Nobuhiko

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

Category: Grant-in-Aid for Scientific Research (B)

Institution: Tohoku University

2017/04/01 - 2020/03/31

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We studied functions of a series of Pt(II)-diradical complexes aimed at application to a probe for theranostics of cancer to provide accurate but affordable diagnostics and therapeutic method. The prerequisites of the probe are functions such as near-infrared (NIR) absorption, its switching, photothermal effect, delivery to cancer cells or tumor, stability in cancer cells. We modeled four Pt(II) complexes that can partially fulfill those prerequisites and successfully obtained guidelines for molecular design of a probe for theranostics. This study is a milestone to provide a clear path to obtain the ultimate probe that can meet the requirement of theranostics and to proceed to animal experiment.
Research and developments on next-generation harmonic ultrafast ultrasound imaging for accurate analysis of cardiovascular dynamics

Hasegawa Hideyuki

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

Category: Grant-in-Aid for Scientific Research (B)

Institution: University of Toyama

2017/04/01 - 2020/03/31

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Cardiovascular diseases are the significant causes of mortality in Japan. Methods for the measurement of the cardiovascular dynamics are required to evaluate the cardiovascular function. Particularly, in evaluation of the cardiac function, a high temporal resolution is desirable because the heart is beating rapidly. However, the temporal resolution of a conventional diagnostic ultrasound system is about 30 frames per second (fps), and it is not enough for evaluation of the cardiac function. In the present study, qualitative observation and quantitative evaluation of cardiac blood flow were realized by high-frame-rate ultrasound imaging at a temporal resolution of over 5000 fps. Also, a new ultrasonic array probe using layered piezoelectric elements was investigated for high-contrast ultrasound imaging using harmonic components in ultrasonic echoes.
Innovative theranostics system with magnetic carbon nanotube

Saijo Yoshifumi, KODAMA Tetsuya, KATO Toshiaki, SIREGAR Syahril

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Research (Exploratory)

Category: Grant-in-Aid for Challenging Research (Exploratory)

Institution: Tohoku University

2017/06/30 - 2019/03/31

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The basis of innovative theranostics system with magnetic carbon nanotube (M-CNT) was investigated. In the diagnostic side, M-CNT for photoacoustic (PA) imaging was developed and non-local means denoising was applied to reduce PA noise. In the therapeutic side, vibration of M-CNT caused by pulsed magnetic field was confirmed and M-CNT behavior during heating was simulated. The results indicate the application of M-CNT and PA imaging for innovative theranostics system.
Advanced human thermophysiological model for evaluating health risks due to thermal environments

GOTO TOMONOBU, TAKAKI RIE

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

Category: Grant-in-Aid for Scientific Research (B)

Institution: Tohoku University

2016/04/01 - 2019/03/31

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In order to establish a new human thermophysiological model which can predict not only body temperature but also blood pressure and blood flow rate, we conducted reference data collections through some experiments and field surveys, and developments of the sub-models which compose our new model. In the experiments and field surveys, we obtained detailed physiological data under six steady-state and two unsteady-state conditions, and data on the daily life fluctuations of exposure temperature, blood pressure, etc. in winter. As the sub-model developments, we improved the thermal network and cardiovascular models, and verified their applicability. In addition, we developed a prototype of the physiological model to simulate the regulations of sweat, blood pressure and blood flow rate.
Development of a novel quantitative blood flow sensor for single ventricle disease newborns

Sai Sadahiro

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)

Category: Grant-in-Aid for Scientific Research (C)

Institution: Tohoku University

2016/04/01 - 2019/03/31

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Despite the recent improvement in the understanding of pathophysiology and the management of the perioperative neonate, the morbidity and mortality rate is not optimal. The aim of this research was to develop a novel, inplantable small sensor to quantify the blood flow both in pulmonary and systemic circulation after Blalock-Taussig shunt operation to improve the perioperative management. Initially, we aimed to explore the way to use polyvinylidene fluoride (PVDF) as a sensor; however, the computer simulation revealed that to obtain enough signal from a small piece of PVDF the huge voltage, which is too danger to yield in the body, would be needed. Therefore, the non-lead seramics was used to develop a sensor, and we successfully manifacutured a 2mm x 2mm size sensor. With those sensors, the flow velocity in a mock circulation made of silicon was capable of being measured by reasonable voltage.
Development of sarcopenia diagnosis device based on 3D-photoacoustic imaging

Hatori Kouki, Saijo Yoshifumi

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)

Category: Grant-in-Aid for Scientific Research (C)

Institution: Matsumoto Dental University

2016/04/01 - 2019/03/31

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Biomedical photoacoustic (PA) imaging system has the unique capability of combining high optical cantrast with high ultrasound (US) resolution in a single modality. When the laser with the wavelength of 532 nm is used, PA signals are reflected from red blood cells. Although the period of the unilateral occlusion induces the chenges of masseter muscle (MM), it is not known that how blood circulation and tissue elasticity of MM are affected by the unilateral occlusion. We aimed to evaluate the sequential changes of MM due to the unilateral occkusion in rats with PA imaging system. PA signals from the MM of the non-occlusal side were significantly lower than that of the occlusalside, and US signals from the MM of the occlusal side were significantly higher than that of non-occlusal side depending on the period of the unilateral occlusion. The PA system can evaluate the blood circulation and the tissue elasticity simultaneously.
Development of photoacoustic flow cytometry by employing multi-channel high frequency ultrasonic probe

Nagaoka Ryo, SAIJO Yoshifumi, UMEMURA Shin-ichiro, YOSHIZAWA Shin, ARAKAWA Mototaka, ISHIKAWA Kazuo

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Research Activity Start-up

Category: Grant-in-Aid for Research Activity Start-up

2016/08/26 - 2018/03/31

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In a traditional photoacoustic flow cytometry, cells in vessels are aligned in one line by laser manipulation, and the photoacoustic signals induced from the cells are measured to classify the characteristics. However, scattering and absorption in the living tissues has effects on the propagation of the radiated laser, and the alignment of the cell by the manipulation cannot be achieved owing to the effect. In this study, the effect of the scattering and absorption was minimized by acoustical focusing, and the method could visualize the living tissues at the deeper part was developed.
Electromagnetic scanning forward viewing ultrasound endoscope equipped in a guide wire

Yoichi Haga

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

Category: Grant-in-Aid for Scientific Research (B)

Institution: Tohoku University

2015/04/01 - 2018/03/31

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An electromagnetic scanning forward viewing ultrasound thin endoscope intended to be equipped in a guide wire has been developed for intravascular treatment. The endoscope consists of a resonator with an ultrasonic transducer and a driving coil. Driving of the electromagnetic resonator was confirmed using the driving coil, 50 um witdth silicon beam and a cylindrical shaped samarium cobalt magnet. Almost element technology has been established for fabrication of the device and equipment in the guide wire and ultrasound imaging will be realized by packaging in thin and small size.
Clarification of fluid dynamical effect of near-wall flow field on enrtherial cell damage by measurement-integrated-simulation

Hayase Toshiyuki

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

Category: Grant-in-Aid for Scientific Research (B)

Institution: Tohoku University

2015/04/01 - 2018/03/31

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It is known that damage on endothelial cells on the surface of a blood vessel causes diseases of blood vessels such as atherosclerosis or aneurisms. However, its mechanism is unknown. This study aimed to clarify the effect of flow field on the endothelial cells’ damage. A complex flow field near the surface of a carotid artery was reconstructed in a flow chamber and experiment of cell peeling by the flow load was conducted. Ultrasonic measurement integrated simulated was also performed to clarify the complex flow field in a carotid artery. Results obtained in this study are expected to be used in developing new diagnostic method of circulatory diseases based on understanding of fluid dynamical effect on cell damages.
Non-invasive visco-elastic imaging for living cells by ultrasound

Hozumi Naohiro, KOBAYASHI KAZUTO

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

Category: Grant-in-Aid for Scientific Research (B)

Institution: Toyohashi University of Technology

2015/04/01 - 2018/03/31

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In this study, we developed an observatoin system that displays quantitatively and continuously the cultured cells continuously and non-invasively using focused ultrasound, and displays with acoustic impedance that is equivalent to elastic parameter. As the condition of the cytoskeleton highly reflects onto the elasticity of the cell, the degenerative process of the cytoskeleton of the cancer cell after being exposed to anticancer drugs, and the differentiation process of the myoblast calls were observed non-invasively and continuously in live condition. Together with the aim of application to regenerative medicine, we attempted to observe iPS cells.
Atrial natriuretic peptide induces peroxisome proliferator

Kawamoto Shunsuke

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)

Category: Grant-in-Aid for Scientific Research (C)

Institution: Tohoku University

2015/04/01 - 2018/03/31

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Atrial natriuretic peptide is a cardiac atriumderived hormone and its cardioprotective effects have recently been confirmed, but the actual mechanism underlying these effects has not been well elucidated. In this study, we proposed that atrial natriuretic peptide achieves its effects in part via peroxisome proliferator activated receptor c, a nuclear receptor. Atrial natriuretic peptide may achieve its cardioprotective effects in part via the activation of the peroxisome proliferator activated receptor c pathway, particularly in central areas of ischemic lesions.
Intra-operative imaging of soft tissue sarcoma with photoacoustic imaging

Watanuki Munenori

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)

Category: Grant-in-Aid for Scientific Research (C)

Institution: Tohoku University

2015/04/01 - 2018/03/31

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Surgery of soft tissue sarcoma is wide resection, which means macroscopically and microscopically complete sarcoma resection with reactive layer and normal tissue around it en bloc. Surgical margin is planned on the basis of pre-operative radiological findings. Under operation, it is quite difficult to confirm boundary between tumor and normal tissue and to judge whether tumor is properly resected. We could make photoacoustic imaging of human osteosarcoma xenograft in athymic nude mice. Photoacoustic imaging may enable intra-operative sarcoma imaging.
Estimation of three-dimensional blood flow vector by super-harmonic echocardiography

SAIJO Yoshifumi

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research

Category: Grant-in-Aid for Challenging Exploratory Research

Institution: Tohoku University

2015/04/01 - 2017/03/31

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A broadband sector ultrasound probe with 64 elements was developed and ultrasound was emitted and received by a programmable ultrasound RF signal processor. Two-dimensional blood flow velocity was deduced by measuring the blood flow vectors from two different viewpoints. The algorithm was validated by a mock blood flow model. Two-dimensional blood flow information on parallel planes were input in three-dimensional equation of continuity and an algorithm for three-dimensional blood flow measurement was developed.
Tomographic imaging of a cell by laser ultrasound microscope with femto-second laser

SAIJO Yoshifumi, MATSUURA Yuji

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

Category: Grant-in-Aid for Scientific Research (B)

Institution: Tohoku University

2014/04/01 - 2017/03/31

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A laser ultrasound microscope with cellular resolution was developed by means of measuring high frequency laser ultrasound signal generated by ultra-short pulsed laser with ZnO thin film sensor. 3T3-L1 cells, which proliferated from fibroblast to adipocyte, were cultured on PET film and observed by the laser ultrasound microscope. C-mode and B-mode images were successfully obtained by the system. The method is capable of measuring sound speed and acoustic impedance and finally visualizes the distribution of Young’s elastic modulus and density within a cell. The method may contribute to the future investigation on cellular biomechanics.
Development of optical fiber probe for all-optic photoacousitc imaging

Matsuura Yuji, SAIJO YOSHIFUMI

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

Category: Grant-in-Aid for Scientific Research (B)

Institution: Tohoku University

2014/04/01 - 2017/03/31

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In this research, optical fiber probes for endoscopic photoacoustic imaging were developed. This probe consists of a bundle of hollow optical fibers delivering excitation laser beams and a single-mode optical fiber with polymer film at the distal end for acoustic detection. A bundle of extremely thin hollow optical fibers was fabricated to improve the resolution and metal coating was applied on the fiber's end to improve the sensitivity for acoustic wave. By using the newly developed probe, photoacoustic images of biomedical samples were successfully obtained.
Development of High-Ouput Ultrasonic Probe for Ultrafast Imaging

Hasegawa Hideyuki

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

Category: Grant-in-Aid for Scientific Research (B)

2014/04/01 - 2017/03/31

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Functional ultrasound imaging is valuable for diagnosis of the circulatory system. Measurement of the tissue dynamics is necessary for functional ultrasound imaging. We have tried to improve the temporal resolution, which is one of the merits of ultrasonography, for accurate measurement of the tissue dynamics. In the present study, an ultrasonic transducer array, to which high input voltage can be applied, was developed for detection of ultrasonic echoes from very weak scatterers, such as blood cells, by increasing the intensity of emitted ultrasound. Also, a multi-channel system for ultrasonic pulse-echo measurement was developed so that high voltages can be applied to the transducer array. Furthermore, we have developed methods for high-contrast ultrasonic imaging and succeeded to visualize weak echoes from blood cells.
Proteomics analysis of frozen shoulder and development of novel therapy and diagnosis

Hagiwara Yoshihiro

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

Category: Grant-in-Aid for Scientific Research (B)

Institution: Tohoku University

2013/04/01 - 2017/03/31

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Joint stiffness is a very common problem in clinical settings. However, there is no consensus as well as appropriate therapy for it. Frozen shoulder is a common disease with a decrease in range of motion (ROM) and pain resulting in disturbing activity of daily living. We collected samples(ther otator interval coracohumeral ligament, and inferior glenohumeral ligament) from frozen shoulder during arthroscopic pancapsular release. They were analyzed with nanoLC/ESI-MSMS for identification of proteins and each relative expression levels by intensity on each LC-MS data.Besides fibrosis and inflammation, increased adhesion and coagulation cascades may deteriorate pathology of idiopathic frozen shoulder.
Development of noninvasive in vivo hard tissue imaging system using photoacoustic microscope

Hatori Kouki, SAIJO Yoshifumi, SASAKI Keiichi, HAGIWARA Yoshihiro

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)

Category: Grant-in-Aid for Scientific Research (C)

Institution: Tohoku University

2013/04/01 - 2016/03/31

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Male Wistar rats of 20-week-old (n=5) were used in this study. Mandibles were resected and fixed. Mandibular condylar cartilage was observed with photoacoustic microscopy (PAS). PAS visualized the lesion from subchondral bone to cancellous bone. Ultrasound microscopy visualized the whole cartilage lesion. Thus PAS could visualized the 3-dimentional color image of from cartilage to cancellous bone. Male Wistar rats of 16-week-old (n=5) were used in this study. Right three molars of maxilla were extracted. After 4 weeks of extraction, both masseter muscles were resected and fixed. Masseter muscle was observed with PAS. Photoacoustic signal was lower in extracted side than in non-extracted side. Ultrasound signal was higher in non^extracted side than in non-extracted side.
Photoacoustic molecular imaging of macrophage with metal nanoparticle

SAIJO YOSHIFUMI, OGASAWARA Koetsu

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research

Category: Grant-in-Aid for Challenging Exploratory Research

Institution: Tohoku University

2013/04/01 - 2015/03/31

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Acoustical-resolution and optical-resolution photoacoustic microscope system were developed. Photoacoustic properties of some metals was measured and macrophage phagocytosing gold nanorod was observed by the system. Photoacoustic imaging of macrophage with gold nanorod has a potential to be a biomarker of inflammation.
Spatio-temporal analysis of blood flow in bifurcation of blood vessel using ultrasonic-measurement-integrated simulation

HAYASE Toshiyuki, OBAYASHI Shigeru, SAIJO Yoshifumi

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

Category: Grant-in-Aid for Scientific Research (B)

Institution: Tohoku University

2012/04/01 - 2015/03/31

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It has been pointed out that hemodynamics has a strong relationship with occurrence and development of circulatory diseases. However primary parameter to these diseases is still unknown. This research was conducted for a simultaneous analysis of blood pressure (BP) and flow in a carotid artery using photoplethysmography (PPG) and two-dimensional ultrasonic-measurement-integrated (2D-UMI) simulation. The system analyzes BP and flow fields from the viewpoint of influence of phases of BP and flow corresponding to forward and backward waves on vessel wall. The simultaneous analysis system using PPG and 2D-UMI simulation was developed, and characteristics of the blood flow field in a carotid artery was clarified focusing on time variation of the phase corresponding to forward and backward waves identified by wave intensity (WI).
Visco-elastic imaging of biological soft tissues using SP hybrid mode ultrasonic microscope

HOZUMI Naohiro, TANAKA Naohiko, YOSHIDA Sachiko, YAMAMOTO Seiji, SAIJO Yoshifumi, KOBAYASHI Kazuto

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

Category: Grant-in-Aid for Scientific Research (B)

Institution: Toyohashi University of Technology

2012/04/01 - 2015/03/31

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We have proposed the acoustic microscope for viscoelastic imaging by utilizing both pressure and shear waves focused on the target. The specimen was placed on an acrylic plaque substrate. Pulsed pressure and shear waves with frequency range of 40 - 120 MHz were sequentially produced in the substrate and focused on the top surface of the substrate where the specimen was attached. The shear wave was produced when the pressure wave in water comes into the substrate with oblique incidence. Reflections were interpreted into bulk modulus, shear modulus and viscosity. Mechanical scan made it possible to acquire 2D profiles of these three parameters. A cancerous liver of rat was quantitatively observed. 2D profiles of bulk modulus, shear modulus and viscosity were displayed. Among these three profiles viscosity profile successfully highlighted the cancerous region. A good agreement with optical image was seen after staining with antibody.
A Study on Ultrasonic Measurement and Visualization of Propagation of Myocardial Contraction Response

KANAI Hiroshi, SAIJO Yoshifumi

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

Category: Grant-in-Aid for Scientific Research (B)

Institution: Tohoku University

2011/04/01 - 2014/03/31

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For realization of non-invasive regional myocardial tissue characterization, in the present study, we tried to elucidate the characteristic of the myocardial response to the electrical excitation by an in vitro experiment using an excised rat left-ventricular wall. To visualize such propagation phenomenon, whose propagation speed is up to several m/s, high frame rate ultrasound was used. Propagation of the myocardial vibration was visualized by estimating the delay time between vibration waveforms measured in the reference ultrasonic beam and each ultrasonic beam using the cross-correlation function between the vibration waveforms. From the estimated delay time, we visualized the propagation of myocardial vibration caused by the electrical excitation. Propagation velocities were estimated to be 2.5 m/s at the internal and external surfaces of the left-ventricular wall. These results correspond to the results obtained in in vivo experiments measured with high frame rate ultrasound.
Study on visualization of defect of internal elastic lamina of arterial wall for diagnosis of very early-stage atherosclerosis

KANAI Hiroshi, SAIJO Yoshifumi, HASEGAWA Hideyuki

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research

Category: Grant-in-Aid for Challenging Exploratory Research

Institution: Tohoku University

2011 - 2012

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It would be useful to measure the minute surface roughness of the carotid arterial wall to detect the endothelial damage in the early-stage of atherosclerosis. In conventional ultrasonography, the axial resolution of a B-mode image depends on the ultrasonic wavelength of 150 μm at 10 MHz. Therefore, the surface roughness caused by atherosclerosis in an early stage cannot be measured using a conventional B-mode image obtained by ultrasonography because the roughness is10-20 μm. We have realized accurate transcutaneous estimation of such a minute surface profile using the lateral motion of the carotid arterial wall, which is estimated by block matching of received ultrasonic signals. The proposed method was proved to be able to measure minute surface profile of about 10 μm by measuring a phantom, which had a saw tooth profile on its surface. Furthermore, the surface roughness of the carotid arterial walls of 10-50 μm were measured reproducibly for three healthy subjects (24-, 23-, and 23-year-old males).
Development of Sono-cytometry by High Frequency Ultrasound

SAIJO Yoshifumi, KANAI Hiroshi, HAYASE Toshiyuki

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research

Category: Grant-in-Aid for Challenging Exploratory Research

Institution: Tohoku University

2011 - 2012

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Microfluidic circulation with suspension of micro-molecules was observed by high speed CCD camera. High frequency ultrasound of 120 MHz was emitted to the model and the spectrum of the reflected ultrasound was analyzed by neural network. The dimensions and structures of the micro-molecules were evaluated by the method. Application of the blood flow or lymph flow to the method in living subjects may realize in vivo “sono-cytometry" in the near future.
Smart-ageing Evaluation of Skin by Acoustic Radiation Force Tracked with High Frequency Ultrasound

SAIJO Yoshifumi, KANAI Hiroshi, HOZUMI Naohiro

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

Category: Grant-in-Aid for Scientific Research (B)

Institution: Tohoku University

2010 - 2012

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Acoustic radiation force (ARF) was applied to the object with 1 MHz ultrasound applicator and the small displacement was measured by phase tracking method of 120 MHz ultrasound. The viscoelastic properties were obtained by analyzing the temporal response of the object to ARF. The efficacy of the method was validated by the measurement of artificial skin with three-layered structure. The method may contribute to smart-ageing evaluation of skin.
Development of Probe System with Super-small Diameter for Intravascular Ultrasound Performing Much Detailed Imaging

TAGAWA Norio, OKUBO Kan, SAIJO Yoshifumi

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

Category: Grant-in-Aid for Scientific Research (B)

Institution: Tokyo Metropolitan University

2009 - 2012

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In this study, we aim to improve the safety and the performance of intravascular ultrasound (IVUS), we proposed a technique to construct an IVUS probe with super-small diameter through the development of the ultra-small ultrasound motor. Additionally, we proposed an actually available ultrasound transmitting/receiving system required for much detailed imaging using the proposed IVUS probe, which is examined from both aspects of hardware and transmitting/receiving schemes. We also developed several signal processing techniques for observed echo signals, and enabled further high quality imaging.
Development of high-resolution 2D-3D hybrid acoustic impedance microscope for biological use

HOZUMI Naohiro, YOSHIDA Sachiko, YAMAMOTO Seiji, SAIJO Yoshifumi, KOBAYASHI Kazuto

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

Category: Grant-in-Aid for Scientific Research (B)

2009 - 2011

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We proposed a new ultrasonic microscope for medical and biological use. The target is placed on a plastic substrate, and ultrasonic signal is transmitted and received across the substrate. In this phase of research, we improved spatial resolution, and observed brain tumor model and cultured glioma cells. As for brain tumor tissue, we succeeded in highlighting the tumor by quantifying" local roughness of acoustic impedance". As for cell size observation, we succeeded in observing morphological change of glioma cells after being exposed to anticancer agent. Finally, we succeeded in three dimensional observation of tumor and cultured cells simultaneously with the observation of cross sectional acoustic impedance image.
Vasa Vasorumの可視化を目的とした光音響顕微鏡の開発

西條芳文, 松浦祐司

Offer Organization: 日本学術振興会

System: 科学研究費助成事業挑戦的萌芽研究

Category: 挑戦的萌芽研究

Institution: 東北大学

2009 - 2010

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冠動脈の動脈硬化プラークの進展及び破綻に密接に関係するVasa vasorumの臨床的評価方法として、血管内超音波法(IVUS)と同様のシステムで、光と音のハイブリッドにより血管内から外膜側の細動脈を特異的に可視化する血管内光音響イメージングが有効と考えられる。本研究では、ナノ秒パルスレーザーの照射により発生する超音波を受信し、プローブを機械的走査することで反射の三次元分布を可視化する光音響顕微鏡装置を試作することで、1.直径50μmの細動脈が可視化できる解像度が得られること、2.使用するレーザー光の波長により血管や動脈硬化組織に特異的なイメージングが可能であることの2点を明らかにすることを研究目的とした。平成22年度には、光ファイバーによりレーザー光を集光するという新たなアーキテクチャーにより光音響信号の三次元分布を計測し、分解能50μmについて確認した。さらに、10色のファントムを作成し、532nmのYAG:Ndレーザー光照射により特に赤色ファン等からの光音響信号が強いという分光性について確認した。
Evaluation of Articular Cartilage with High Frequency Ultrasound Imaging System

HAGIWARA Yoshihiro, SAIJO Yoshifumi

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B)

Category: Grant-in-Aid for Young Scientists (B)

Institution: Tohoku University

2009 - 2010

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A newly developed high-frequency ultrasound imaging system (HFUIS) provides noncontact high-resolution 3D ultrasound (US) imaging. A Transducer with central frequency of 120 MHz and a focal length of 3.2 mm was most appropriate for evaluating the articular cartilage. We divided the articular cartilage in three layers (superficial, middle and deep layers) and compare the images with those of scanning acoustic microscope (SAM). A high relative intensity by HFUIS and high sound speed area by SAM had strong correlations (Pearson product moment correlation, superficial layer: 0.704, middle layer: 0.731).
A Study on Noninvasive Ultrasonic Measurement of Minute Mechanical-Excitation Wave-front Propagation in Human Myocardial Tissue and Its Visualization

KANAI Hiroshi, SAIJO Yoshifumi, HASEGAWA Hideyuki

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

Category: Grant-in-Aid for Scientific Research (B)

Institution: Tohoku University

2008 - 2010

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Complexity of the cardiac contraction sequence is still not fully understood because the dynamic mechanical excitation process, which directly correlates with contraction, cannot be accurately measured based on the electro-magnetic phenomena. By developing a noninvasive novel imaging modality with high temporal and spatial resolutions, the present study shows that the propagation of the mechanical wave-front occurs at the beginning of cardiac contraction sequence for the first time (about 60 ms prior to the ordinarily accepted onset time of the contraction). From the apical side of the interventricular septum, a minute velocity component with an amplitude of several tenth micrometers is generated and it propagates from the apex to the base of the posterior wall, and then from the base to the apex of the septum, with a propagation speed of 3-9 m/s. This dynamic measurement modality is also applicable to various tissues in biology.
Evaluation of Angiogenesis by High Resolution Three-dimensional Ultrasound Molecular Imaging

SAIJO Yoshifumi, SATO Yasufumi, KODAMA Tetsuya

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

Category: Grant-in-Aid for Scientific Research (B)

Institution: Tohoku University

2007 - 2009

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High resolution three-dimensional ultrasound molecular imaging was developed for evaluation of angiogenesis in small animals such as mice. The following were achieved ; 1. Three-dimensional ultrasound imaging system with the frequency range up to 150 MHz and the spatial resolution of 10 micron, 2. Image analysis algorithm for classification of vessels and surrounding tissues by correlation of RF signals in the consecutive frames, 3. Portable scanner for easy and repetitive use, 4. Molecular imaging of angiogenesis with labeled nano-bubble.
Development of a passive-active artificialmyocardium reconcilingthe physiological demands with hemodynamic changes

SHIRAISHI Yasuyuki, YAMBE Tomoyuki, SAIJO Yoshifumi, UMEZU Mitsuo, FUJIMOTO Tetsuo, BABA Atsushi, TABAYASHI Koichi, HOMMA Dai

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (A)

Category: Grant-in-Aid for Young Scientists (A)

Institution: Tohoku University

2007 - 2009

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We developed a sophisticated artificial myocardium which consisted of shape memory alloy fibre units. We applied the PID method for the control of myocardial assist, and examined the dynamic performance as well as hemodynamic changes in goats. It was anticipated that the passive-active artificial myocardium control could be achieved which was reconciling the physiological demands with pathophysiological diagnosis by using our new methodology.
Clinical evaluation of a noninvasive estimation system for cardiac function

YOSHIZAWA Makoto, NITTA Shinichi, YAMBE Tomoyuki, SAIJO Yoshifumi, TANAKA Akira, SHIRAISHI Yasuyuki

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

Category: Grant-in-Aid for Scientific Research (B)

Institution: Tohoku University

2006 - 2008
Development of High-speed Microprobe for in vivo Observation of Biological Tissue Using Pulsed Ultrasound

HOZUMI Naohiro, MASAYUKI Naga, YOSHIFUMI Saijo, YOSHIDA Sachiko, KOBAYASHI Kazuto

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

Category: Grant-in-Aid for Scientific Research (B)

Institution: Aichi Institute of Technology

2006 - 2008
傾斜スケール磁気粒子流体の生体適合化による先進医工学への新展開

西山秀哉, 山家智之, 西條芳文, 高奈秀匡

Offer Organization: 日本学術振興会

System: 科学研究費助成事業萌芽研究

Category: 萌芽研究

Institution: 東北大学

2006 - 2007

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工業用バルブや医療用シール等のMR流体流動システム設計のための基礎資料を提供することを目的として、磁場下にある最新の商用MR流体の詳細なレオロジー特性とオリジナルな可視化実験、圧力流れ場における矩形流路内流動構造の経時変化の実験解析、さらには、矩形流路内流量遮断特性から磁気機能性および流動制御特性を明らかにした。その結果、以下の結論を得た。 1.MR流体の流動曲線や降伏応力の再現性を確認するために、回転粘度計のMR流体試料と接触する回転スピンドルの頂角、円板ギャップ表面粗さによるレオロジー特性への影響を詳細に明らかにした。静的な降伏応力はずり速度が小さい場合、表面粗さがあると滑面に比して大きく、強磁場下でせん断力は平板ギャップが大きいと増加する。これは、棒状クラスター端面と回転スピンドル表面との摩擦力やすべりが影響していると考えられる。 2.圧力流れ場における流路内MR流体シールを破壊するためのピストン移動速度を0.5〜5mm/sに大きく変化させるために、平成18年度に製作したMRシールシステムを試作改良した。 3.磁場下でピストン駆動速度を変化させた場合のMR流体流路の最上流部、シール下端部の圧力の経時変化により、シール形成による流動遮断、シール崩壊および流動、さらには、シール再形成のシナリオをリアルタイムで明らかにした。いずれのピストン駆動速度においても、印加磁場強度の増加と共にシール耐圧が増加し、その増加率は印加磁場強度の二乗にほぼ比例する。また、ピストン駆動速度の増加に対しても、シール耐圧は著しく増加する。これは、ピストン駆動速度の増加に伴い、磁場作用近傍のシール上流部で強磁性微粒子密度が局所的に増加することにより、より強固なクラスターが形成されたためと考えられる。
極早期段階の動脈硬化診断のための内皮反応性の高感度計測に関する研究

金井浩, 西條芳文, 長谷川英之

Offer Organization: 日本学術振興会

System: 科学研究費助成事業萌芽研究

Category: 萌芽研究

Institution: 東北大学

2006 - 2007

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本研究では,内皮由来血管弛緩反応に伴って中膜が柔らかくなる現象を,超音波を用いて皮膚から直接計測するための高精度計測法を新たに開発し,内皮の障害も含め,動脈硬化症の無徴候性段階での検出も含めた動脈硬化症の極早期診断法の確立を目指している. 1.1拍内での血管壁の『応力-歪みヒステリシス特性』の評価を可能とする手法とシステムの開発を行った.(1)前年度に開発した連続計測システムを用いて,右腕の血管壁の1拍中での数μmという僅かな厚み変化を80秒間計測した. 同時に左腕の同じ位置で連続計測する血圧波形から,血管壁の1拍での『応力-歪み特性』を算出し,そのヒステリシス特性から動脈壁の弾性特性・粘性特性を評価した.(2)in vivo計測を実施し,駆血解除後の血管反応性に伴い,血管壁(平滑筋からなる内膜・中膜領域)での弾性値・粘性値が,60秒間連続計測できる計測システムを構築した. 2.ヒトの生理的刺激に対する血管内皮機能を評価した.上記のシステムを健常者に適用して血管反応性を評価したところ,血管駆血前の応力-歪みヒステリシス特性に対し,駆血解除直後においてヒステリシスが太くなって粘性が増加し,同時にヒステリシスの傾きが減少して弾性値も減少する現象,その約60秒後には,もとの駆血前の状態に戻る様子が観察された.これは生理学的にも説明ができる結果であり,これらの現象を非侵襲的に世界で初めて計測可能とした成果には大きな意義がある. 3.駆血をせずに血管内皮機能を評価するための方法の新たな開発をするため,自転車漕ぎによって血流を増加させたときの血管壁での内皮由来血管弛緩反応が検出できるかを調べたが,計測対象の微小な厚み変化に比べ,手の動きが大きく,これらの計測の精度を上げることは今後の課題である.
Research on diastolic properties of the myocardium by imaging propagation of shear wave along heart wall

KANAI Hiroshi, HASEGAWA Hideyuki, SAIJO Yoshifumi

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)

Category: Grant-in-Aid for Scientific Research (A)

Institution: Tohoku University

2005 - 2007

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By ultrasonic measurement of the myocardial motion, we have already found that pulsive waves are spontaneously excited by aortic-valve closure at end-systole. Since myocardial viscoelasticity is essential in the evaluation of heart diastolic properties, this study makes the physiological phenomenon to be measured noninvasively measured in vivo as follows: 1 Using a sparse sector scan, the pulsive waves were measured almost simultaneously at several thousand points set along the heart wall at a sufficiently high frame rate. The consecutive spatial phase distributions clearly revealed wave propagation along the heart wall. The phase velocity of the wave is determined for each frequency component. By comparing the dispersion of the phase velocity with the theoretical one of the Lamb wave, which propagates along the viscoelastic plate immersed in blood, the instantaneous viscoelasticity is determined noninvasively. 2 We realized the principle of the measurement in a clinical ultrasonic diagnostic system. 3 By actuating a small pulse in an elastic spherical shell, which was made as a model of the heart, we confirmed that the viscoelasticity of the spherical shell can be measured with an error less than 10% of the viscoelasticity measured by the mechanical test. 4 By applying the developed method to 5 healthy subjects, we confirmed the sufficient reproducibility of the propagation velocity of the pulsive wave among the consecutive cardiac cycles. 5 We confirmed that the difference among the viscoelasticity values estimated from the 5 subjects is less than 20% and the transient of the viscoelasticity just after the aortic valve closure is similar. The viscoelasticity estimates are similar to those measured for the canine heart wall in literature. 6 By applying the method to 10 patients with old myocardial infarction, we found that the amplitude and the propagation speed were decreased in each of the diseased areas. These results correspond to that obtained by using the longitudinal waves in literature. 7 In conclusion, based on the new findings, we developed a means to measure the myocardial viscoelasticity in vivo. These clinical results indicate that the method has a potential for noninvasively revealing myocardial heterogeneity.
心臓壁内で自発的に生起した高周波パルス状振動の伝搬特性のイメージングに関する研究

金井浩, 西條芳文

Offer Organization: 日本学術振興会

System: 科学研究費助成事業萌芽研究

Category: 萌芽研究

Institution: 東北大学

2004 - 2005

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本研究の目的は,心臓壁に沿って伝搬するパルス状振動の伝搬状態と伝搬速度を,100Hzまでの周波数帯域でイメージングするための超音波計測方法を確立し,高精度心臓疾患診断の可能性を探究するとともに,数百Hzまでの振動成分による医療診断という新しい研究分野の開拓する.下記の研究を行い,各項目に関して十分な成果を得た. 1.水槽実験によるパルス状振動の伝搬速度の内圧依存性の検討(金井) シリコーンゴムによる弾性球殻を作製し,水槽実験において,パルス状振動が球殻壁上を伝搬する速度を超音波により計測した.ヒトの心臓壁に近い粘弾性特性をもつシリコーンゴムを用いたところ,ほぼヒトの心臓を同じ5m/s程度の伝搬速度が得られた.さらにヒトでは,大動脈弁の閉鎖タイミングにおいて内圧は急激に変化しているため,弾性球殻の内圧を変化させ,球殻を伝搬するパルス状波形の伝搬速度を計測したところ,内圧の低い場合に比較して,内圧を高くした場合に,伝搬速度が速くなる現象が得られた.ヒトに関して得られた結果を裏付けることができた.しかし,1つの波形伝搬中においても伝搬速度に変化があり,これがヒトの場合の伝搬速度の減少に対応する可能性もあることが見出された. 2.伝搬速度の周波数分散の計測とイメージング(金井) 心臓壁内に設定した多数点でほぼ同時に計測されたパルス状振動波形を周波数解析することによって,100Hz成分までの各周波数成分に関する伝搬速度を決定できる計測法を開発し,伝搬速度に大きな速度分散性があることを確認した.これは,心臓の壁の粘弾性によるものであり,心筋の粘弾性を決定できる. 3.心臓疾患患者への適用(西條・金井) 心疾患患者へ適用し,特に心筋梗塞患者の梗塞部位に,このパルス状振動が伝搬しないことを見出した.これは患部の同定にとって非常に重要な知見といえる. 4.本研究の総括(金井) 以上,心筋梗塞による壊死領域の同定などの心臓疾患の診断を非侵襲で高精度に行うことが可能となり,臨床医学的な意義も大きいものと期待できる.
Ultrasonic Nano-imaging of Vascular Endothelial Cell

SAIJO Yoshifumi, SATO Masaaki, HOZUMI Naohiro, SUZUKI Satoshi

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

Category: Grant-in-Aid for Scientific Research (B)

Institution: Tohoku University

2003 - 2005

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For precise imaging of cells, pre-treatments such as antibody sensing are needed in electron scanning microscopy and laser scanning microscopy with fluorescence technique. Non-contact nano-imaging of cells without pre-treatment is anticipated for repeated measurements under various conditions. The objective of the present research is to develop a nano-imaging system that can measure sound speed, attenuation and acoustic impedance of cells with high frequency ultrasound. Further, we compare the distribution of acoustic properties within a cell and cytoskeleton such as actin filaments or tubulin in order to prove the usefulness of the system in the measurement of cellular biomechanics. An electric pulse with the pulse width of 2 ns was generated by high speed mechanical switching was directly input into the ultrasonic transducer. The pulse response was analyzed by a digital oscilloscope. Two servo linear motors controlled by a microcomputer board were used for the scanning in both x- and y-axis of the imaging system. The total system was controlled by a workstation and 300x300 points data acquisition was done within two minutes. The interference between reflections from the surface of the specimen and the interface between the specimen and a glass slide was analyzed in frequency domain. The algorithm for calculation of the thickness and the sound speed of the specimen was established and finally two-dimensional mapping of quantitative sound speed distribution was displayed. Cooling effect of pulmonary vascular endothelial cells was investigated with actin filaments staining, electric impedance measurement and nano-imaging system. The results indicated the usefulness of the system for investigation of cellular biomechanics.
Development of Sound Speed Microscope for Nano-scale Imaging of Biological Tissue Using Pico-second Ultrasonic Pulse

HOZUMI Naohiro, NAGAO Masayuki, SAIJO Yoshifumi, KOBAYASHI Kazuto

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

Category: Grant-in-Aid for Scientific Research (B)

Institution: Toyohashi University of Technology

2003 - 2005

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Observation of biological tissue by ultrasonic micro-imaging has advantages of being non-destructive and non-contacting, making it possible to quantitatively obtain physical parameters like sound speed and attenuation. We have been developing an ultrasonic sound speed microscope for biological tissues. A thin sliced specimen is placed on a glass substrate, and the reflection of a focused ultrasound pulse with a wide band frequency is interpreted into sound speed and other parameters. A 2D image can be observed when the focal beam spot is mechanically scanned. Its clinical application to histopathological examination during surgery is being considered. The data are also important to assess the origin of clinical echographic imaging. However, the lateral resolution of conventional one used to be as poor as 15 micrometers, although one with a higher resolution was expected to bring important information in biological and medical point of view. In this research project, we aimed to develop an ultrasonic microscope with a resolution of sub-micron level. An ultrasonic microscope using a wide-band pulse spreading from 100-500 MHz was assembled. A piezo-electric stage was employed in order to obtain a resolution of sub-micron level. Cultured nerve cells taken from the hippocampus of a rat was clearly observed as both intensity and sound speed images. In addition, it was clarified that the reflected wave at the interface between the substrate and tissue can be measured when the acoustic wave was transmitted from the rear side of the substrate. Therefore the reflection was visualized as two-dimensional profile of acoustic impedance, in order to observe the tissue without preparing a thin sliced specimen. The structure of the cerebella tissue of a rat was clearly observed as an acoustic impedance image.
An Investigation on Noninvasive Measurement of Transmural Distribution of Myocardial Systolic Function and Diastolic Properties Using Ultrasound

KANAI Hiroshi, SAIJO Yoshifumi

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

Category: Grant-in-Aid for Scientific Research (B)

Institution: Tohoku University

2003 - 2004

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For the serious heart diseases, the different transmural layers of the myocardium have transmural heterogeneity with respect to the strength of contraction. A method for measuring such transmural heterogeneity with sufficient spatial resolution has never been developed. In this study, a method for noninvasive measurement of the intramyocardial contraction/relaxation heterogeneity by evaluating the change in thickness or its speed in two dimensions and its measurement system were developed. Moreover, a novel method for measuring the myocardial viscoelasticity was developed and its principle was confirmed by the basic experiments and in vivo experiments as follows : 1.In this study, a method for noninvasive measurement of the intramyocardial contraction/relaxation heterogeneity by evaluating the change in thickness or its speed in two dimensions and its measurement system were developed. 2.Based on the basic experiments using a spherical shell made of silicone rubber, which physical parameters are known, as a heart-mimicking phantom, the accuracy of the measurement of the developed method was confirmed. 3.Moreover, this study developed the following novel method for noninvasively measuring the myocardial viscoelasticity at the beginning of diastole and for imaging the transmural heterogeneity in the propagation of the elastic waves. The method was applied to healthy subjects and patients with heart diseases. By this method, a velocity signal of the heart wall can be successfully detected with sufficient reproducibility. In this study, the pulsive waves were measured almost simultaneously at about 160 points set along the heart wall at a sufficiently high frame rate. The consecutive spatial phase distributions, obtained by the Fourier transform of the measured waves, clearly revealed wave propagation along the heart wall for the first time. Based on this phenomenon, we developed a means to measure the myocardial viscoelasticity in vivo using the model of the Lamb wave propagation in a viscoelastic plate. This method has a potential to noninvasively evaluate the myocardial viscoelasticity.
Quantitative evaluation of local biomechanics of thoracic aorta

SAI Sadahiro, TABAYASHI Koichi, SATO Masaaki, SAIJO Yoshifumi, ODA Katsuhiko

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)

Category: Grant-in-Aid for Scientific Research (C)

Institution: Tohoku University

2003 - 2004

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The objectives of the present study are to develop a quantitative measurement system of biomechanics of aortic wall by applying ultrasound diagnostics device and to establish an objective indication for rupture of aneurysm and operation. The concrete object of the research during grant-in-aid is to measure the local elasticity of aortic wall by using intravascular ultrasound (IVUS) and transesophageal echocardiography. (TEE) Radio-frequency (RF) signal of clinical IVUS apparatus was sampled via analogue/digital (A/D) converter with sampling rate of 500 MSa/s and stored in a workstation. Electrocardiogram and intracoronary pressure were also sampled via A/D converter with 10 kSa/s, simultaneously. The correlation and displacement of RF lines of the same address in neighboring flames were calculated. Assuming that high correlation area indicated vascular wall, automatic recognition of vascular wall was performed. Tissue velocity was calculated as the difference of the frames was 33 ms. Tissue Velocity Imaging was defined as the tissue velocity in high correlation areas. Short axis view of descending aorta was obtained by a TEE with the central frequency of 4-7 MHz. Electrocardiogram and blood pressure were recorded simultaneously. Two dimensional tissue velocity, vectors were calculated by template matching method of squared region of interests in neighboring frames. IVUS findings and excised specimen by directional coronary atherectomy were compared and TEE findings and surgicaly excised specimen were compared The passive movement by blood pressure variance was correlated with tissue components and expression of inflammatory cells such as macrophages. Finally, precise measurement of biomechanics by applying ultrasonic technology was shown in the present research.
Development of Noninvasive Estimation system of Maximum Ventricular Elastance Emax for Clinical Application

YOSHIZAWA Makoto, YAMBE Tomoyuki, ABE Kenichi, NITTA Shin-ichi, TANAKA Akira, SAIJO Yoshifumi

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)

Category: Grant-in-Aid for Scientific Research (C)

Institution: Tohoku University

2002 - 2003

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The maximum ventricular elastance (Emax) is a good quantitative index for evaluating cardiac pump function. To extensively promote clinical application of Emax, it is necessary to need a new method for obtaining Emax without high invasive measurements. The purpose of this research was to develop a clinical method for estimating Emax low-invasively without any cardiac load on the of the parameter optimization method (POM) and the linear elastance method (LEM) that has been proposed by the authors. Because the POM and LEM need left ventricular pressure (LVP) and aortic flow (AoF), we have also developed a technique to estimate these signals in the following. First, the system we have developed can estimate LVP on the basis of two ARX (autoregressive exogeneous) models : the system model from radial arterial pressure (RdP) to aortic pressure (AoP) and the system model from AoP to LVP, respectively ; In a cardiac catheterization test, these ARX models can be identified by using LVP, AoP and RdP. LVP and AoP are invasive measurements but RdP is measured noninvasively by a tonometric pressure sensor. Once these models are identified, it is guessed that LVP can be estimated fully noninvasively by using RdP even after the previous cardiac catheterization test. Secondly, the developed system can estimate AoF by automatically extracting the contour of Doppler echocardiography during the ejection period. Finally, the total system has been completed in a personal computer unit so as to estimate Emax on the basis of the POM using the off-line data of RdP and the Doppler image of aortic flow rate. An input module has been added to the system to apply the system to real clinical use.
Development of Intravascular Acoustic Microscopy System

SAIJO Yoshifumi, KANAI Hiroshi, YAMBE Tomoyuki, NITTA Shin-ichi, OKADA Nagaya, OHTSUKI Shigeo

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

Category: Grant-in-Aid for Scientific Research (B)

Institution: Tohoku University

2001 - 2003

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The cause of acute coronary syndromes such as acute myocardial infarction or unstable angina has been revealed as the rupture of a vulnerable plaque in a coronary artery. The objective of the research project was to develop an intravascular acoustic microscope system applicable to clinical settings. The concrete purpose during the term of Grant-in Aid for Scientific Research was to establish an ultrasonic diagnostic system with 40 MHz frequency which can provide greater information compared with a conventional intravascular ultrasound (IVUS) system. The radio-frequency (RF) signal from a conventional IVUS apparatus was digitized by a high speed A/D converter with a sampling frequency of 500 MSa/s. The ECG and intracoronary pressure were simultaneously digitized and stored in a workstation. Conventional IVUS images and Integrated Backscatter Imaging derived from automatic sensitivity time compensation. RF signals of the same portion in consecutive frames were analyzed and correlation and displacement were calculated. Tissue Velocity Imaging was defined as two-dimensional distribution of the displacement in 1/30 sec where the correlation was 0.7 or more. Tissue Strain Imaging was derived from the tissue velocity difference between two points considering intracoronary pressure change. Normal coronary artery, soft plaque and hard plaque were visualized by the system. The strain of the soft plaque was larger than that of normal coronary artery and the strain was greatly changed during one cardiac cycle. The clinical results suggest the efficiency of the system to assess the pathophysiology of acute coronary syndromes.
Development of a physiologically effective control system for an artificial heart based on autonomic nerve activity

NITTA Shin-ichi, KONNO Satoshi, SAIJO Yoshifumi, YAMBE Tomoyuki, TANAKA Akira, YOSHIZAWA Makoto

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)

Category: Grant-in-Aid for Scientific Research (A)

Institution: Tohoku University

2000 - 2003

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In recent years, the application of Ventricular Assist Devices (VAD) has been gradually expanded due to the lack of heart donors and increasing morbidity of cardiovascular diseases. However, there hasn't been an established method for controlling VAD/Total Artificial Heart (TAH) system which can provide physiologically effective circulatory support for a prolonged period of time. Although most investigators adopted an approach to controlling VAD/TAH according to cardiac output or aortic pressure, these conventional methods are not fully reflecting circulatory responses and are reported to occur long-term complications such as thyroid dysfunction or increased central venous pressure. To solve this issue, we newly developed a biocompatible stainless-steel neural interface and successfully recorded autonomic nerve activity of an awake VAD-implanted goat for more than a month. Then we applied fractal dimension analysis, a non-linear analysis method suitable for evaluating complicated biological information, to quantify the changes in autonomic nerve activities. As a result, shifts of the fractal dimension of autonomic nerve activity were observed in response to the changes in circulatory dynamics and posture of animals. Based on the analysis of recorded autonomic nerve activities, a real-time VAD/TAH control system by using fractal analysis-based feedback control algorithm was constructed. Now we attempt to examine the validity of this algorithm and improve it through animal experiments.
Control of Aging by the use of Artificial Organs

YAMBE Tomoyuki, SAIJO Yoshifumi, NITTA Shin-ichi, YOSHIZAWA Makoto, TABAYASHI Kou-ichi, TANAKA Akira

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

Category: Grant-in-Aid for Scientific Research (B)

Institution: Tohoku university

1999 - 2002

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Since an aging society comes unescapable, we cope with various diseases by the Aging, and have the necessity of aiming at the society where healthy elderly people play an active part. Although an Aging phenomenon can also be considered to be change of the whole body, in the medical spot, it servers as generating of the illness of an internal-organs unit. The illnesses of an internal-organs unit are various medicines and adaptation of a surgical operation. To the internal-organs malfunction which has advanced irreversibl, radical correspondence of transplantation, an artificial organ, etc. becomes indispensable to life maintenance. Therefore, a possibility that support of high-tech medical treatments, such as an articial organ, will become unescapable at the healthy aging society is high. It is becoming old memory with collapse of the Communist bloc that the long-term struggle for existence of the animal experiment of an artificial heart was performed having applied national prestige all over the world. There is an opinion about which it whispered between the artificial heart researchers in the world from that time. It is "aging of the animal after implanting an artificial heart is early ?" It is the hypothesis to say. To pathophysiological change which can be regarded also as promotion of such an Aging after implanting an artificial heart, the syndrome of a "artificial heart syndrome" was proposed in the University of Tokyo. Research on change of the heart blood vessel system in connection with various artificial circulation and Agings has been done even in Tohoku University. The Institute of Development, Aging and Cancer in Tohoku University carried out the research subject "the nonlinear analysis of the artificial heart animal as an Aging promotion model" by the support of the test research from the Ministry of Education science research cost. Cousequently, the artificial heart chronic animal as an Aging promotion model was established. Based on this result, the Ministry of Education, Culture, Sports, Science and Technology science research cost base research "research on control of the Aging phenomenon by chaos control of an artificial organ" was done from 1999 to 2003. Our results suggested the feasibility of control of Aging by the use of the artificial organs.
低容量超音波による血管内皮細胞への情報伝達

西條芳文

Offer Organization: 日本学術振興会

System: 科学研究費助成事業奨励研究(A)

Category: 奨励研究(A)

Institution: 東北大学

2000 - 2001

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本研究の目的は、組織に温度上昇やキャビテーションなどによる障害を与えない程度の低容最の超音波を照射し、血管内皮細胞へ情報伝達を行うことが可能かどうかについて検討することである。直径3cm厚み5mmのPZT平面振動子を直径35mm高さ1cmの円盤状のシャーレ中心に取り付け、インキュベータ中に設置可能なサイズの小型超音波照射装置を作製した。外部の超音波発生装置(ファンクション・ジェネレータ)にて周波数、超音波強度をコントロールし、超音波照射装置に信号を入力した。ウシ大動脈血管内皮細胞(Bovine Aortic Endothelium Cell:以下BAEC)を使用して実験を行った。35mmのディッシュにDulbecco's Modified Eagle's medium(DMEM)と10%ウシ胎児血清を加え、CO2濃度5%、温度37?に設定されたインキュベータ内にてBAECをconfluentな状態になるまで培養した。BAECをPhosphate Buffered Saline(PBS)で2回洗浄した後、カルシウムイオンに対する蛍光色素であるCa gree-1(2μM)を加えて室温で30分間細胞内に取り込ませた。細胞内に取り込まれなかった蛍光色素を洗浄し、DMEM4mlを加えたものをコントロール群と超音波照射群にわけて観察を行った。超音波照射群に対しては周波数1MHzの微弱超音波をディッシュの下方より照射し、蛍光顕微鏡にて経時的な細胞内カルシウムイオン濃度の変化を3分間にわたって観察した。超音波照射群では照射開始直後に約10%の一過性の蛍光強度の上昇が観察され、コントロール群ではこのような上昇は観察されなかった。これは微弱超音波がメカニカルな刺激となり、細胞内でのカルシウムイオン濃度を上昇させたためと考えられた。
高周波数超音波による血管内皮細胞のバイオメカニクスの定量的評価方法の開発

西條芳文

Offer Organization: 日本学術振興会

System: 科学研究費助成事業奨励研究(A)

Category: 奨励研究(A)

Institution: 東北大学

1998 - 1999

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超音波顕微鏡は高周波数超音波を音響レンズにより集束させ、機械的走査により対象物の音響特性の2次元分布を表示することを基本原理とする。超音波は弾性波としての性質を有するため、音響特性と物理的特性とは密接な関連がある。具体的には超音波の減衰は物質の粘性に、音速は弾性に強く関係しているので、粘弾性体と仮定される細胞のバイオメカニクス計測に対して、超音波顕微鏡は非常に有効な手段となる。本研究では使用周波数100〜200MHzの超音波顕微鏡により、血管内皮細胞の音響特性を計測した。ウシ大動脈血管内皮細胞(BAEC)に流れによる「ずり応力」を24時間与えたところ、細胞の形態は流れの方向に引き伸ばされた。超音波顕微鏡による音響的計測で、核の音速は1610m/sで不変であったが、細胞質の音速は1570m/sから1590m/sに上昇した。ヒト臍帯静脈血管内皮細胞(HUVEC)にエンドトキシン刺激を与え、前後で超音波顕微鏡によりその形態と音響特性を計測したところ、刺激後には細胞質の減衰は上昇し、その分布は不均一になった。これらの結果から、血管内皮細胞に対する刺激に対する反応を、超音波顕微鏡にて検出可能であることが証明された。超音波顕微鏡は、細胞に対する蛍光抗体などの前処理が不要で、細胞に非接触で計測でき、将来的にはin vivoにおいても応用可能であるため、細胞のバイオメカニクス計測に有用であることが示された。

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Social Activities 5

Education of Medicine and Biomedical Engineering for Engineers (EMBEE)

2019/05 - Present
楽しい理科のはなし

河北新報

2012 - Present
[日本国内] 名取市生活習慣病検診

2007/06/28 - 2007/07/01

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2次検診および頚動脈エコー検査や携帯電話による積極的介入へのフィールドワーク
[日本国内] 利府町住民講演会

2006/09/04 -

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利府町住民に「メタボリックシンドロームと動脈硬化」について講演
[日本国内] 第3回市民のための心臓病講演会

2006/07/06 -

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メタボリックシンドロームと高脂血症

Media Coverage 9

高度救急医療情報伝送

河北新報

2009/12/28

Type: Newspaper, magazine
高度救急医療伝送

NHK

2009/10/07

Type: TV or radio program
知的クラスター創生事業報告会

河北新報

2009/05/28

Type: Newspaper, magazine
知的クラスター創生事業報告会

NHK

2009/05/27

Type: TV or radio program
[日本国内] 冬場の心臓発作

NHKラジオ第一放送

2007/11/16

Type: Other
[日本国内] 三次元超音波顕微鏡

河北新報

2007/10/25

Type: Newspaper, magazine
[日本国内] 三次元超音波顕微鏡

ミヤギテレビ

2007/10/25

Type: TV or radio program
[日本国内] 熱中症について

NHKラジオ第一放送

2007/07/20

Type: Other

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熱中症とは何か、メカニズム、対策などについて
超音波画像診断装置の開発

日本経済新聞

2007/06/29

Type: Newspaper, magazine

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Other 6

超微細超高感度センシングによる疾患の早期発見・兆候検出技術の開発（ウェルネス・センシング）

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周波数3.5MHzの電子走査型リニアスキャンを用いたポータブル超音波センサのプロトタイプを作製する。周波数60MHzに対応可能な超高精度機械走査型超音波診断装置を設計し、機械走査部および周波数20MHzの超音波送受信部を作製する。
三次元複合臓器構造体研究開発

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最新の材料・生物化学と三次元造型技術、非侵襲評価技術を駆使して、形態的にも機能的にも生態に類似した三次元複合臓器構造体を実現するため、作製過程あるいは移植後生体内での変化が連続モニタリング可能なプロセス評価を実現する非侵襲・低侵襲的評価法を確立することを目的に委託業務を実施する。
生体内超音波ナノ・イメージング法の開発

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周波数1.2GHzの超音波を生体組織上で2次元スキャンし、組織表面からの超音波の反射強度の違いを画像化することで、解像度800ナノメートルの生体内超音波ナノ・イメージング方法を開発する。
パルス励起型超音波音速顕微鏡の開発

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パルス励起型超音波音速顕微鏡の開発
微弱超音波による血管内皮細胞のNO産生制御

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微弱超音波による血管内皮細胞のNO産生制御
エンドトキシン刺激に対する血管内皮細胞の形態変化メカニズムの解明？超音波顕微鏡による細胞の粘弾性変化の計測？

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エンドトキシン刺激に対する血管内皮細胞の形態変化メカニズムの解明？超音波顕微鏡による細胞の粘弾性変化の計測？

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