顔写真

アンザイ ヒトミ
安西 眸
Hitomi Anzai
所属
流体科学研究所 流動創成研究部門 生体流動ダイナミクス研究分野
職名
助教
学位
  • 博士(工学)(東北大学)

  • 修士(工学)(東北大学)

委員歴 1

  • 日本機械学会 バイオエンジニアリング部門 若手による次世代戦略委員会 若手による次世代戦略委員会 委員

    2021年4月 ~ 継続中

所属学協会 2

  • 日本バイオレオロジー学会

  • 日本機械学会

研究キーワード 3

  • 構造最適化

  • 脳動脈瘤

  • 数値流体力学

研究分野 1

  • ライフサイエンス / 生体医工学 /

受賞 3

  1. Poster Award

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

  2. Poster Award

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

  3. Outstanding Award for Poster

    2010年11月3日 Seventh international Conference on Flow Dynamics

論文 96

  1. The influence of blood velocity and vessel geometric parameters on wall shear stress

    Fangjia Pan, Naoko Mori, Shunji Mugikura, Makoto Ohta, Hitomi Anzai

    Medical Engineering & Physics 2024年2月

    DOI: 10.1016/j.medengphy.2024.104112  

  2. Physics-informed neural networks (PINNs) for 4D hemodynamics prediction: An investigation of optimal framework based on vascular morphology

    Xuelan Zhang, Baoyan Mao, Yue Che, Jiaheng Kang, Mingyao Luo, Aike Qiao, Youjun Liu, Hitomi Anzai, Makoto Ohta, Yuting Guo, Gaoyang Li

    Computers in Biology and Medicine 2023年9月

    DOI: 10.1016/j.compbiomed.2023.107287  

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

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

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

    DOI: 10.3233/THC-230194  

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

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

    Haoran Wang, Makoto Ohta, Hitomi Anzai, Jiayuan Ji

    SUSTAINABILITY 15 (15) 2023年8月

    出版者・発行元:MDPI

    DOI: 10.3390/su151511959  

    eISSN:2071-1050

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

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

    Yutaro Kohata, Makoto Ohta, Kazuyoshi Jin, Hitomi Anzai

    Frontiers in medical technology 5 1196125-1196125 2023年

    DOI: 10.3389/fmedt.2023.1196125  

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

  6. A Review of Functional Analysis of Endothelial Cells in Flow Chambers

    Makoto Ohta, Naoya Sakamoto, Kenichi Funamoto, Zi Wang, Yukiko Kojima, Hitomi Anzai

    JOURNAL OF FUNCTIONAL BIOMATERIALS 13 (3) 2022年9月

    出版者・発行元:MDPI

    DOI: 10.3390/jfb13030092  

    eISSN:2079-4983

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    The vascular endothelial cells constitute the innermost layer. The cells are exposed to mechanical stress by the flow, causing them to express their functions. To elucidate the functions, methods involving seeding endothelial cells as a layer in a chamber were studied. The chambers are known as parallel plate, T-chamber, step, cone plate, and stretch. The stimulated functions or signals from endothelial cells by flows are extensively connected to other outer layers of arteries or organs. The coculture layer was developed in a chamber to investigate the interaction between smooth muscle cells in the middle layer of the blood vessel wall in vascular physiology and pathology. Additionally, the microfabrication technology used to create a chamber for a microfluidic device involves both mechanical and chemical stimulation of cells to show their dynamics in in vivo microenvironments. The purpose of this study is to summarize the blood flow (flow inducing) for the functions connecting to endothelial cells and blood vessels, and to find directions for future chamber and device developments for further understanding and application of vascular functions. The relationship between chamber design flow, cell layers, and microfluidics was studied.

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

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

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

    出版者・発行元:NATURE PORTFOLIO

    DOI: 10.1038/s41598-022-18788-3  

    ISSN:2045-2322

    eISSN:2045-2322

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

  8. A Parametric Study of Flushing Conditions for Improvement of Angioscopy Visibility

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

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

    出版者・発行元:MDPI

    DOI: 10.3390/jfb13020069  

    eISSN:2079-4983

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

  9. Comparing the Effect of Helical-centerline Stent Placement on Blood Flow Velocity with a Straight Stent

    Yutaro Kohata, Hitomi Anzai, Makoto Ohta

    2022年5月24日

    DOI: 10.1101/2022.05.22.492620  

  10. A machine learning strategy for fast prediction of cardiac function based on peripheral pulse wave. 国際誌 査読有り

    Sirui Wang, Dandan Wu, Gaoyang Li, Xiaorui Song, Aike Qiao, Ruichen Li, Youjun Liu, Hitomi Anzai, Hao Liu

    Computer methods and programs in biomedicine 216 106664-106664 2022年4月

    出版者・発行元:ELSEVIER IRELAND LTD

    DOI: 10.1016/j.cmpb.2022.106664  

    ISSN:0169-2607

    eISSN:1872-7565

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    OBJECTIVE: Pulse wave has been considered as a message carrier in the cardiovascular system (CVS), capable of inferring CVS conditions while diagnosing cardiovascular diseases (CVDs). Clarification and prediction of cardiovascular function by means of powerful feature-abstraction capability of machine learning method based on pulse wave is of great clinical significance in health monitoring and CVDs diagnosis, which remains poorly studied. METHODS: Here we propose a machine learning (ML)-based strategy aiming to achieve a fast and accurate prediction of three cardiovascular function parameters based on a 412-subject database of pulse waves. We proposed and optimized an ML-based model with multi-layered, fully connected network while building up two high-quality pulse wave datasets comprising a healthy-subject group and a CVD-subject group to predict arterial compliance (AC), total peripheral resistance (TPR), and stroke volume (SV), which are essential messengers in monitoring CVS conditions. RESULTS: Our ML model is validated through consistency analysis of the ML-predicted three cardiovascular function parameters with clinical measurements and is proven through error analysis to have capability of achieving a high-accurate prediction on TPR and SV for both healthy-subject group (accuracy: 85.3%, 86.9%) and CVD-subject group (accuracy: 88.3%, 89.2%). DISCUSSION: The independent sample t-test proved that our subject groups could represent the typical physiological characteristics of the corresponding population. While we have more subjects in our datasets rather than previous studies after strict data screening, the proposed ML-based strategy needs to be further improved to achieve a disease-specific prediction of heart failure and other CVDs through training with larger datasets and clinical measurements. CONCLUSION: Our study points to the feasibility and potential of the pulse wave-based prediction of physiological and pathological CVS conditions in clinical application.

  11. Estimation of Blood Flow in a Stent using Time Intensity Curve Analysis

    Yutaro Kohata, Hitomi Anzai, Makoto Ohta

    UTM-IFS 3rd International Biofluid Symposium 2021 2021年11月

  12. Influences brought by different wall shear stress analysis on curved vessels

    Fangjia Pan, Naoko Mori, Shunji Mugikura, Hitomi Anzai, Makoto Ohta

    UTM-IFS 3rd International Biofluid Symposium 2021 2021年11月

  13. Endothelial Cell Distribution within Gap between Two Stent Struts after Flow Exposure

    Zi Wang, Narendra Kurnia Putra, Hitomi Anzai, Naofumi Ohtsu, Yukiko Kojima, Hanif Saifurrahman, Makoto Ohta

    UTM-IFS 3rd International Biofluid Symposium 2021 2021年11月

  14. 広めたい! 血流 CFD の環 招待有り

    安西眸, 太田 信, 庄島 正明, 藤村 宗一郎, 八木 高伸

    第 37 回 NPO 法人日本脳神経血管内治療学会学術集会 2021年11月

  15. Evaluation of Normalization Methods in a Cerebral Artery Atlas for Automatic Labeling 査読有り

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

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

    出版者・発行元:American Society of Mechanical Engineers

    DOI: 10.1115/imece2021-71097  

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

  16. Numerical Simulation in Lower Airway Using Eulerian Wall Film Model: Influence of Mucus Viscosity on Droplet Generation

    Yugo Shindo, Shunji Mugikura, Naoko Mori, Takaaki Akaike, Tetsuro Matsunaga, Makoto Ohta, Hitomi Anzai

    Eighteenth International Conference on Flow Dynamics - ICFD 2021 2021年10月

  17. Assessing of the Relationship between WSS and TAV for Disturbed Flow on the Geometry of AVF for Hemodialysis

    Kazuki Takeda, Hitomi Anzai, Mingzi Zhang, Wang Haoran, Ai Kajiyama, Makoto Ohta

    Eighteenth International Conference on Flow Dynamics - ICFD 2021 2021年10月

  18. Assessment of the thermal outcome during steam-pulse ablation for sheep tissue 査読有り

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

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

    出版者・発行元:Elsevier BV

    DOI: 10.1016/j.tsep.2021.100966  

    ISSN:2451-9049

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    Thermal ablation has attracted attention as a minimally invasive tissue ablation treatment. Steam flow was recently introduced as a novel ablation procedure. This work aimed to assess the applicability of pulsated steam flow for tumor ablation. Ex vivo ablation was performed using liver, muscle, and fat tissues of sheep. Three experimental protocols of pulse number were administered to these tissues, while computational simulation was conducted according to the ex vivo tests for each tissue. Real-time measurements of temperature revealed heat propagation during and subsequent to ablation. The peak temperature was achieved after ablation. The time to reach the peak (highest temperature) increased with the distance from the thermal sensor to the steam needle according to thermal conductivity, except for steam leakage along to gap between the tissue and blood vessel. A cross-section of the ablated specimen clearly revealed the boundaries of cell defects. The ablated area was droplet shaped up to the steam needle. Computational simulations revealed that the ablated area was consistent with the area with the highest temperature. Though several limitations still remain such as no blood circulation, pulsated steam flow can ablate diverse animal tissues.

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

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

    Technology and health care : official journal of the European Society for Engineering and Medicine 30 (2) 351-359 2021年7月23日

    出版者・発行元:IOS PRESS

    DOI: 10.3233/THC-212905  

    ISSN:0928-7329

    eISSN:1878-7401

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

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

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

    International journal for numerical methods in biomedical engineering 37 (7) e3465 2021年7月

    出版者・発行元:WILEY

    DOI: 10.1002/cnm.3465  

    ISSN:2040-7939

    eISSN:2040-7947

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

  21. Deep leaning network for predicting cardiovascular hemodynamics 招待有り

    Hitomi Anzai, Gaoyang Li, Keiichiro Shiraishi, Makoto Ohta

    Biofluids 2021 "Biofluid Symposium" 2021年6月

  22. Endothelial cells distribution after the flow exposure experiment

    Z. Wang, H. Anzai, Y. Kojima, N. K. Putra, J.-P. Rieu, N. Ohtsu, H. Taniho, M. Ohta

    Lyon Saint Etienne & Nippon Scientific Network Engineering sciences Lyon Tohoku LyonSE&N – ELyT Workshop 2021 2021年6月

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

    Y. Kohata, H. Anzai, M. Decroocq, S. Rit, C. Frindel, M. Ohta

    Lyon Saint Etienne & Nippon Scientific Network Engineering sciences Lyon Tohoku LyonSE&N – ELyT Workshop 2021 2021年6月

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

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

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

    出版者・発行元:BMJ PUBLISHING GROUP

    DOI: 10.1136/neurintsurg-2020-016724  

    ISSN:1759-8478

    eISSN:1759-8486

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

  25. ステント表面内皮化に対する流れ負荷実験の有用性

    小島有紀子, 王子, Narendra Kurnia Putra, 大津直史, 安西眸, 太田信

    2021年度 東北大学金属材料研究所共同研究ワークショップ・日本バイオマテリアル学会東北ブロック講演会 2021年

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

    白石 敬一郎, 太田 信, 安西 眸, リー ガオヤン

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

    出版者・発行元:公益社団法人 日本生体医工学会

    DOI: 10.11239/jsmbe.annual59.510  

    ISSN:1347-443X

    eISSN:1881-4379

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

  27. Numerical Simulation of Flow Behavior in Basilar Bifurcation Aneurysms Based on 4-Dimensional Computed Tomography Angiography 査読有り

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

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

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

    DOI: 10.4236/wjm.2021.114006  

    ISSN:2160-049X

    eISSN:2160-0503

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

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

    Frontiers in physiology 12 733767-733767 2021年

    出版者・発行元:FRONTIERS MEDIA SA

    DOI: 10.3389/fphys.2021.733767  

    ISSN:1664-042X

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

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

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

    Frontiers in physiology 12 733547-733547 2021年

    出版者・発行元:FRONTIERS MEDIA SA

    DOI: 10.3389/fphys.2021.733547  

    eISSN:1664-042X

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

  30. Preface

    Takashi Tokumasu, Hitomi Anzai, Koji Fujita, Kenichi Funamoto, Makoto Hirota, Hisashi Nakamura, Koji Shimoyama, Hidemasa Takana

    JOURNAL OF FLUID SCIENCE AND TECHNOLOGY 16 (1) 2021年

    出版者・発行元:JAPAN SOC MECHANICAL ENGINEERS

    DOI: 10.1299/jfst.2021jfst0001  

    ISSN:1880-5558

  31. Prediction of 3D Cardiovascular hemodynamics before and after coronary artery bypass surgery via deep learning 国際誌 査読有り

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

    COMMUNICATIONS BIOLOGY 4 (1) 99-99 2021年1月

    出版者・発行元:NATURE RESEARCH

    DOI: 10.1038/s42003-020-01638-1  

    eISSN:2399-3642

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    The clinical treatment planning of coronary heart disease requires hemodynamic parameters to provide proper guidance. Computational fluid dynamics (CFD) is gradually used in the simulation of cardiovascular hemodynamics. However, for the patient-specific model, the complex operation and high computational cost of CFD hinder its clinical application. To deal with these problems, we develop cardiovascular hemodynamic point datasets and a dual sampling channel deep learning network, which can analyze and reproduce the relationship between the cardiovascular geometry and internal hemodynamics. The statistical analysis shows that the hemodynamic prediction results of deep learning are in agreement with the conventional CFD method, but the calculation time is reduced 600-fold. In terms of over 2 million nodes, prediction accuracy of around 90%, computational efficiency to predict cardiovascular hemodynamics within 1 second, and universality for evaluating complex arterial system, our deep learning method can meet the needs of most situations. Anzai et al. propose a deep learning approach to estimate the 3D hemodynamics of complex aorta-coronary artery geometry in the context of coronary artery bypass surgery. Their method reduces the calculation time 600-fold, while allowing high resolution and similar accuracy as traditional computational fluid dynamics (CFD) method.

  32. Hemodynamic-Based Evaluation on Thrombosis Risk of Fusiform Coronary Artery Aneurysms Using Computational Fluid Dynamic Simulation Method 査読有り

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

    COMPLEXITY 2020 2020年10月

    出版者・発行元:WILEY-HINDAWI

    DOI: 10.1155/2020/8507273  

    ISSN:1076-2787

    eISSN:1099-0526

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

  33. A Hemodynamic-Based Evaluation of Applying Different Types of Coronary Artery Bypass Grafts to Coronary Artery Aneurysms 査読有り

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

    COMPLEXITY 2020 2020年6月

    出版者・発行元:WILEY-HINDAWI

    DOI: 10.1155/2020/9359340  

    ISSN:1076-2787

    eISSN:1099-0526

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

  34. The Relationship Between the Arterial Geometry and Wall Shear Stress in the Vertebrobasilar System 査読有り

    Pan, Fangjia, Anzai, Hitomi, Mugikura, Shunji, Kitamura, Ko, and Ohta, Makoto

    Proceedings of the ASME 2019 International Mechanical Engineering Congress and Exposition Volume 3: Biomedical and Biotechnology Engineering V003T04A038 2020年1月

  35. INFLUENCE OF INPUT IMAGE CONFIGURATIONS ON OUTPUT OF A CONVLUTIONAL NEURAL NETWORK TO DETECT CEREBRAL ANEURYSMS 査読有り

    Kazuhiro Watanabe, Hitomi Anzai, Norman Juchler, Sven Hirsch, Philippe Bijlenga, Makoto Ohta

    Proceedings of the ASME 2019 International Mechanical Engineering Congress and Exposition Volume 3: Biomedical and Biotechnology Engineering V003T04A021 2020年1月

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

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

    TECHNOLOGY AND HEALTH CARE 28 (4) 345-354 2020年

    出版者・発行元:IOS PRESS

    DOI: 10.3233/THC-191911  

    ISSN:0928-7329

    eISSN:1878-7401

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

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

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

    SCIENTIFIC REPORTS 9 (1) 14930-14930 2019年10月

    出版者・発行元:NATURE PUBLISHING GROUP

    DOI: 10.1038/s41598-019-51334-2  

    ISSN:2045-2322

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

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

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

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

  39. Preface

    Takashi Tokumasu, Hitomi Anzai, Koji Fujita, Makoto Hirota, Hisashi Nakamura, Koji Shimoyama, Hidemasa Takana

    JOURNAL OF FLUID SCIENCE AND TECHNOLOGY 14 (3) 2019年

    出版者・発行元:JAPAN SOC MECHANICAL ENGINEERS

    DOI: 10.1299/jfst.2019jfst0014  

    ISSN:1880-5558

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

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

    MEDICAL & BIOLOGICAL ENGINEERING & COMPUTING 57 (1) 15-26 2019年1月

    出版者・発行元:SPRINGER HEIDELBERG

    DOI: 10.1007/s11517-018-1864-6  

    ISSN:0140-0118

    eISSN:1741-0444

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

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

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

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

    出版者・発行元:TECH SCIENCE PRESS

    DOI: 10.31614/cmes.2018.04113  

    ISSN:1526-1492

    eISSN:1526-1506

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

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

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

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

    DOI: 10.1109/EMBC.2018.8513517  

    ISSN:1557-170X

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

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

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

    PROCEEDINGS OF THE ASME INTERNATIONAL MECHANICAL ENGINEERING CONGRESS AND EXPOSITION, 2017, VOL 3 3 2018年

    出版者・発行元:AMER SOC MECHANICAL ENGINEERS

    DOI: 10.1115/IMECE2017-71346  

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    Cancellous bone contains bone marrow where hematopoietic stem cells (HSCs) are produced. Those cells represent an interest in the treatment of leukemia during which transplantation of bone marrow is performed to replace patient degraded cells. HSCs are usually harvested by a puncture in the cancellous bone of the donor's ilium using a needle. However, this procedure can cause severe burden to the donor because of its high invasiveness. The flow of bone marrow is strongly related to the harvesting of HSCs and permeability is one of the major parameters to characterize cancellous bone. Previous researches have already shown an anisotropy of permeability in femur, whereas punctures are usually performed in the iliac cancellous bone.The objective of this paper is to characterize the anisotropic permeability of iliac cancellous bone.Digital images of a porcine iliac cancellous bone sample were obtained by micro-computed tomography (micro-CT), and three locations were selected to fabricate bone models, reproduced by 3D printing at three times magnification. To compare the structure of manufactured models, porosity and its variations along X, Y and Z direction were evaluated from micro-CT images.To measure permeability, a specific perfusion system was developed. The pressure drop between the upstream and the downstream of bone models were measured at different flow rates, reaching a Reynolds number of 27-158, appropriate for the aspiration condition. Darcy-Forchheimer's law was then applied to calculate the permeability and Forchheimer coefficient of bone models.Results revealed different porosities and resultant permeabilities for each bone nodels. A positive correlation links those two parameters. Different fluctuations of porosity were evaluated along each direction although no significant difference of average porosity was observed. On the other hand, different permeabilities and Forchheimer coefficients were measured in each direction with various degrees of anisotropy. Permeabilities in three orthogonal directions of the model ranged from 1.96x10(-10) to 4.29X10(-10) m(2). Results indicate that transport properties in cancellous bone depend on the flow directions. The anisotropy of permeability can be used for evaluation of flow in cancellous bone.

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

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

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

    出版者・発行元:IEEE

    DOI: 10.1109/EMBC.2017.8037081  

    ISSN:1557-170X

    eISSN:1558-4615

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

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

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

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

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

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

    生体医工学 55 (5) 415-415 2017年

    出版者・発行元:公益社団法人 日本生体医工学会

    DOI: 10.11239/jsmbe.55Annual.415  

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

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

    Tupin Simon, Anzai Hitomi, Ohta Makoto

    生体医工学 55 (5) 416-416 2017年

    出版者・発行元:公益社団法人 日本生体医工学会

    DOI: 10.11239/jsmbe.55Annual.416  

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

  48. In Search for a Better Stent: Surrogate based Multi-Objective Optimization of Stent Design under Influence of Vessel Wall Deformation

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

    2017 39TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY (EMBC) 1344-1347 2017年

    出版者・発行元:IEEE

    ISSN:1094-687X

    eISSN:1558-4615

    詳細を見る 詳細を閉じる

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

  49. Stent Design Optimization based on Kriging Surrogate Model under Deformed Vessel Wall: Pulsatile Inlet Flow 査読有り

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

    2017 5TH INTERNATIONAL CONFERENCE ON INSTRUMENTATION, CONTROL, AND AUTOMATION (ICA) 172-176 2017年

    出版者・発行元:IEEE

    DOI: 10.1109/ICA.2017.8068435  

    ISSN:2379-755X

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

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

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

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

    出版者・発行元:AMER SOC MECHANICAL ENGINEERS

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

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

    Kazuhiro Watanabe, Hitomi Anzai, Makoto Ohta

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

    出版者・発行元:AMER SOC MECHANICAL ENGINEERS

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

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

    Narendra Kurnia Putra, Hitomi Anzai, Makoto Ohta

    PROCEEDINGS OF 2017 5TH INTERNATIONAL CONFERENCE ON INSTRUMENTATION, COMMUNICATIONS, INFORMATION TECHNOLOGY, AND BIOMEDICAL ENGINEERING (ICICI-BME) 57-61 2017年

    出版者・発行元:IEEE

    ISSN:2158-0456

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    Human blood Ilow is naturally working as a pulsatile flow under the influence of heartbeat cycle. As many blood flow simulation studies have been conducted recently, many assumption and simplification of intravascular flow phenomena were used as the boundary condition of the simulation. For example, stent contact rigid wall condition, steady blood tlow also material simple models and properties of tissues and blood. However, these simplifications may lead to inaccuracy of the results and analysis. This paper tries to observe the simulation results from different boundary conditions which include the pulsatile flow conditions and how it behaves compared to the steady flow. From the investigation and comparison, the difference between results of flow parameters obtained from the pulsatile and steady simulation shows 2.2% deviation on the appearance of low WSS along the deployment area.

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

    Mingzi Zhang, Hitomi Anzai, Bastien Chopard, Makoto Ohta

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

    出版者・発行元:BIOMED CENTRAL LTD

    DOI: 10.1186/s12938-016-0257-z  

    ISSN:1475-925X

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

  54. Suppression of wall shear stress inside intracranial aneurysms by simple stents 招待有り 査読有り

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

    Neuroscience Communications 2 2016年9月5日

    DOI: 10.14800/nc.1396  

  55. 医工学分野におけるCAVE活用 招待有り

    安西眸, 渡邉和浩, ZHANG Mingi, PUTRA Narendra Kurnia, 竹島由里子, 太田信

    可視化情報学会誌 36 (143) 20-24 2016年

    ISSN:0916-4731

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

    Mingzi Zhang, Hitomi Anzai, Bastien Chopard, Makoto Ohta

    11th World Congress of Structural and Multidisciplinary Optimization (WCSMO-11) 1 310-315 2015年6月

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

    Makoto Ohta, Hitomi Anzai, Yukihisa Miura, Toshio Nakayama

    BIOMATERIALS AND BIOMECHANICS IN BIOENGINEERING 2 (2) 111-125 2015年6月

    出版者・発行元:TECHNO-PRESS

    DOI: 10.12989/bme.2015.2.2.111  

    ISSN:2465-9835

    eISSN:2465-9959

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    For engineers, generating a mesh in porous media (PMs) sometimes represents a smaller computational load than generating realistic stent geometries with computer fluid dynamics (CFD). For this reason, PMs have recently become attractive to mimic flow-diverter stents (FDs), which are used to treat intracranial aneurysms. PMs function by introducing a hydraulic resistance using Darcy's law; therefore, the pressure drop may be computed by test sections parallel and perpendicular to the main flow direction. However, in previous studies, the pressure drop parallel to the flow may have depended on the width of the gap between the stent and the wall of the test section. Furthermore, the influence of parameters such as the test section geometry and the distance over which the pressure drops was not clear. Given these problems, computing the pressure drop parallel to the flow becomes extremely difficult. The aim of the present study is to resolve this lack of information for stent modeling using PM and to compute the pressure drop using several methods to estimate the influence of the relevant parameters.To determine the pressure drop as a function of distance, an FD was placed parallel and perpendicular to the flow in test sections with rectangular geometries. The inclined angle method was employed to extrapolate the flow patterns in the parallel direction. A similar approach was applied with a cylindrical geometry to estimate loss due to pipe friction. Additionally, the pressure drops were computed by using CFD. To determine if the balance of pressure drops (parallel vs perpendicular) affects flow patterns, we calculated the flow patterns for an ideal aneurysm using PMs with various ratios of parallel pressure drop to perpendicular pressure drop. The results show that pressure drop in the parallel direction depends on test section. The PM thickness and the ratio of parallel permeability to perpendicular permeability affect the flow pattern in an ideal aneurysm. Based on the permeability ratio and the flow patterns, the pressure drop in the parallel direction can be determined.

  58. Flow in cancellous bone

    Wataru Sakuma, Hitomi Anzai, Toshio Nakayama, Makoto Ohta

    2015 ELyT lab Workshop 2015年2月20日

  59. Optimization of endovascular prosthesis for the treatment ofcerebral aneurysms

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

    2015 ELyT lab Workshop 2015年2月20日

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

    Mingzi Zhang, Hitomi Anzai, Makoto Ohta

    2015 ELyT lab Workshop 2015年2月

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

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

    TECHNOLOGY AND HEALTH CARE 23 (5) 547-556 2015年

    出版者・発行元:IOS PRESS

    DOI: 10.3233/THC-151007  

    ISSN:0928-7329

    eISSN:1878-7401

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    BACKGROUND: Optimal design of stents for a cerebral aneurysm is desired for efficient flow reduction in the aneurysm. OBJECTIVE: In this study, we aimed to optimize stent design at several porosities, estimate the influence of stent design on aneurysm flow, and evaluate the ability of stents to reduce flow. METHODS: Stentmodels were constructed as sets of squares or rectangles in the necks of a two-dimensional (2D) and realistic aneurysm. Then, automated optimization was performed using a combination of simulated annealing and lattice Boltzmann flow simulation. RESULTS: By simulated annealing, stents were gradually modified to reduce the average velocity in an aneurysm. As a result of optimization, stents of all porosities demonstrated an inhomogeneous distribution with dense struts in the inflow area. Flow reduction was increased compared with the initial stent. Under the condition of high porosity, flow reduction by the stent drastically increased as porosity decreased. Under low porosity, the increase of velocity reduction was moderate even as porosity decreased. CONCLUSIONS: Optimization can enhance flow reduction by stents. However, the increase in reduction associated with decreasing porosity is moderate under lower-porosity conditions. This threshold may help in the choice of stent porosity for each specific aneurysm.

  62. Automation of design optimization for intracranial stent

    Hitomi Anzai, Yuuki Yoshida, Mingzi Zhang, Makoto Ohta

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

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

    Mingzi Zhang, Hitomi Anzai, Bastien Chopard, Makoto Ohta

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

  64. Development of Image Guided Minimal Invasive Treatments

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

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

  65. Optimization of stent design for intracranial aneurysm

    Hitomi Anzai, Yuuki Yoshida, Makoto Ohta

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

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

    Mingzi Zhang, Hitomi Anzai, Makoto Ohta

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

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

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

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

  68. Analysys of optimized design of stent

    H. Anzai

    Interdisciplinary Cerebrovascular Symposium 2014年6月3日

  69. Optimization of Strut Placement in Flow Diverter Stents for Four Different Aneurysm Configurations 国際誌 査読有り

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

    JOURNAL OF BIOMECHANICAL ENGINEERING-TRANSACTIONS OF THE ASME 136 (6) 061006-061006 2014年6月

    出版者・発行元:ASME

    DOI: 10.1115/1.4027411  

    ISSN:0148-0731

    eISSN:1528-8951

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

  70. Combinational Optimization of Strut Placement for Intracranial Stent Using a Realistic Aneurysm 査読有り

    Hitomi Anzai, Bastien Chopard, Makoto Ohta

    Journal of Flow Control, Measurement & Visualization 2 (2) 67-77 2014年4月

    DOI: 10.4236/jfcmv.2014.22009  

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

    Yujie Li, Hitomi Anzai, Toshio Nakayama, Makoto Ohta

    Abstract 2014年2月

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

    Mingzi Zhang, Hitomi Anzai, Makoto Ohta

    Abstract 2014年2月

  73. Study of blood flow in cerebral aneurysm with coil

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

    Abstract 2014年2月

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

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

    Journal of Biomechanical Science and Engineering 9 (1) JSBE0003-JSBE0003 2014年

    出版者・発行元:Japan Society of Mechanical Engineers

    DOI: 10.1299/jbse.2014jbse0003  

    ISSN:1880-9863

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

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

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

    APCOM & ISCM 2013年12月

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

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

    APCOM & ISCM 2013年12月

  77. Optimized Stent 招待有り

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

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

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

    Makoto Ohta, Bastien Chopard, Hitomi Anzai

    AFI/TFI 2013年11月

  79. Optimization of stent design to increase the porosity

    Yuuki Yoshida, Hitomi Anzai, Makoto Ohta

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

  80. Optimization of blood flow for intracranial stent

    Makoto Ohta, Hitomi Anzai, Han Xiaobo

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

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

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

    INTERNATIONAL JOURNAL OF MEDICAL ROBOTICS AND COMPUTER ASSISTED SURGERY 9 (2) 213-222 2013年6月

    出版者・発行元:WILEY

    DOI: 10.1002/rcs.1487  

    ISSN:1478-5951

    eISSN:1478-596X

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    Background The development of new diagnostic technologies for cerebrovascular diseases requires an understanding of the mechanism behind the growth and rupture of cerebral aneurysms. To provide a comprehensive diagnosis and prognosis of this disease, it is desirable to evaluate wall shear stress, pressure, deformation and strain in the aneurysm region, based on information provided by medical imaging technologies. Methods In this research, we propose a new cyber-physical system composed of in vitro dynamic strain experimental measurements and computational fluid dynamics (CFD) simulation for the diagnosis of cerebral aneurysms. A CFD simulation and a scaled-up membranous silicone model of a cerebral aneurysm were completed, based on patient-specific data recorded in August 2008. In vitro blood flow simulation was realized with the use of a specialized pump. A vision system was also developed to measure the strain at different regions on the model by way of pulsating blood flow circulating inside the model. Results Experimental results show that distance and area strain maxima were larger near the aneurysm neck (0.042 and 0.052), followed by the aneurysm dome (0.023 and 0.04) and finally the main blood vessel section (0.01 and 0.014). These results were complemented by a CFD simulation for the addition of wall shear stress, oscillatory shear index and aneurysm formation index. Diagnosis results using imaging obtained in August 2008 are consistent with the monitored aneurysm growth in 2011. Conclusion The presented study demonstrates a new experimental platform for measuring dynamic strain within cerebral aneurysms. This platform is also complemented by a CFD simulation for advanced diagnosis and prediction of the growth tendency of an aneurysm in endovascular surgery. Copyright (c) 2013 John Wiley & Sons, Ltd.

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

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

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

  83. Modeling Flow Diverter Stent using Porous Media

    Makoto Ohta, Yukihisa Miura, Hitomi Anzai, Toshio Nakayama

    Abstract 2012年10月

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

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

    Abstract 2012年10月

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

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

    Proceedings Ninth International Conference on Flow Dynamics 2012年9月

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

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

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

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

    Mingzi Zhang, Hitomi Anzai, Youjun Liu, Makoto Ohta

    不明 412-413 2012年9月

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

    Makoto Ohta, Bastien Chopard, Hitomi Anzai

    不明 98-99 2012年9月

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

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

    不明 2012年7月

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

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

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

    DOI: 10.4103/1793-5482.103706  

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

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

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

    JOURNAL OF COMPUTATIONAL SCIENCE 3 (1-2) 1-7 2012年1月

    出版者・発行元:ELSEVIER SCIENCE BV

    DOI: 10.1016/j.jocs.2011.12.006  

    ISSN:1877-7503

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    A modern technique to treat cerebral aneurysms is to insert a flow diverter in the parent artery. In order to produce an optimal design of such devices, we consider a methodology combining simulated annealing optimization and lattice Boltzmann simulations. Our results surpass, in terms of stent efficiency, those obtained in the recent literature with an other optimization method. Although our approach is still in 2D, it demonstrates the potential of the method. We give some hint on how the 3D cases can be investigated. (C) 2012 Elsevier B.V. All rights reserved.

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

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

    2012 IEEE/RSJ INTERNATIONAL CONFERENCE ON INTELLIGENT ROBOTS AND SYSTEMS (IROS) 4137-4142 2012年

    出版者・発行元:IEEE

    DOI: 10.1109/IROS.2012.6385754  

    ISSN:2153-0858

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    For the development of artificial intelligent diagnosis for cerebrovasclar intervention, it is desirable to forecast the growth of cerebral aneurysms. In order to achieve such purpose, it is needed to evaluate wall shear stress, strain, pressure, deformation and flow velocity in the aneurysm region. In this research, we focus on in-vitro strain and deformation measurements of cerebral aneurysm models, and propose a cyber-physical system, in which a scaled-up membranous silicone model of cerebral aneurysm was built and integrated with a specialized pump for the pulsatile blood flow simulation, and a vision system was constructed to measure the strain on different regions on the model with pulsatile blood flow circulated inside. Experimental results show that both distance and area strain maxima were larger for the aneurysm neck (0.042 and 0.052), followed by the aneurysm dome (0.023 and 0.04) and then by the main blood vessel section (0.01 and 0.014), which were complemented with computer fluid dynamics simulation for the inclusion of wall shear stress, oscillatory shear index and aneurysm formation index. Medical imaging data of the cerebral aneurysm in 2008 and 2011 was obtained. Diagnosis results have concordance with the aneurysm growth in 2011. The presented measurement method offers an option for measuring strain and deformation to be complementary with computer fluid dynamics and photoelastic stress analysis for advanced diagnostic in the endovascular surgery.

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

    入江恵子, 太田信, 安西眸, 根來真, 廣瀬雄一

    CI研究 33 (2) 119-125 2011年

    ISSN:0918-7073

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

    Hitomi Anzai, Toshio Nakayama, Yuriko Takeshima, Makoto Ohta

    PROCEEDINGS OF THE ASME FLUIDS ENGINEERING DIVISION SUMMER CONFERENCE - 2010 - VOL 1, PTS A-C 1859-1867 2010年

    出版者・発行元:AMER SOC MECHANICAL ENGINEERS

    詳細を見る 詳細を閉じる

    Cerebral aneurysms generally occur at arterial bifurcations and arterial curves in or near the circle of Willis. For the treatment of this disorder, stent placement has been valued as a minimal invasive therapy. The effect of stents on flow reduction in cerebral aneurysms has been examined in several computed fluid dynamics (CFD) studies, suggesting that the stent position or the strut shape may affect flow reduction. However, the position of the stent with the best effect on flow reduction is still unknown because of the flow complexity. Three-dimensional visualization may help to easily specify the inflow zone from the parent artery to the aneurysm and to find the relationship between the effective strut position and the flow pattern. However, confirmation of the ability of 3D visualization to determine the effective position of a stent has not been achieved. In this study, we simulated blood flow with several aneurysm geometries to confirm the effect of 3D visualization on determination of optimal stent position.First, flow simulation using real aneurysm geometries without a stent was performed as a "pre-stenting situation." Meshes were generated using a commercial code (Gambit 2.3, Fluent Inc., NH). CFD was carried out using a commercial code (Fluent 6.3, Fluent Inc., NH) based on steady flow. The streamlines around an aneurysm were visualized using a 3D visualization system (EnSight Gold 8.2, Comuputational Engineering Inc., NC) in Realization Workspace (RWS) to visualize the inflow zone.Secondly, a rectangular solid as a strut model was set in the inflow zone using computer-aided design (CAD) techniques. CFD was then performed as a "post-stenting situation" under the same conditions as the pre-stenting situation using the same mesh generator and CFD code.Three-dimensional visualization showed an inflow zone in the aneurysm. A bundle of flow streamlines hit the wall of the neck of the aneurysm and entered it. The inflow zone was a narrow local part in contrast to the outflow.After setting a strut, a change of flow pattern could be observed. The flow speed and the wall shear stress (WSS) were both reduced. When the strut position was moved away from the original position, the flow speed and the WSS were not reduced.These results may suggest that 3D visualization can provide information useful for strut positioning to realize effective reduction of flow into an aneurysm, especially a side wall aneurysm.

  95. 微生物をめぐる最近の知見 黄色ブドウ球菌γヘモリジンが形成するヘテロヘプタマー膜孔複合体の立体構造予測と分子配置解析 査読有り

    冨田典子, 安西眸, 阿部和代, 太田信

    顕微鏡 45 (4) 223-228 2010年

    出版者・発行元:公益社団法人 日本顕微鏡学会

    DOI: 10.11410/kenbikyo.45.4_223  

    ISSN:1349-0958

    eISSN:2434-2386

    詳細を見る 詳細を閉じる

    黄色ブドウ球菌γヘモリジンは34 kDaのHlg1成分と32 kDaのHlg2成分から成る2成分性溶血毒素である.筆者らは,2成分が血球上で3:4または4:3の割合で交互に並んで集合し,リング状のヘテロヘプタマー膜孔複合体を形成することを明らかとしてきた.本研究では,未だ明らかとされていないγヘモリジン膜孔複合体の立体構造を再構築することを目的とし,高精細電子顕微鏡像を基に,ヘテロ7量体非対称性構造に特徴的な分子配置を解析し,正7角形からのずれを伴った立体構造の予測をおこなった.電顕像からサブユニットの形状および大きさを計測し,3次元構造を設計した.膜孔は上部が円柱構造,下部は分子が内側に折れ曲がり底部に小孔が付随した漏斗状構造をしていると予測された.さらに,対角線法および画像解析により,ある隣接サブユニット間が正7角形から約15°離れる方向にずれて配置されていることが明らかとなった.

  96. 3TA5-05 黄色ブドウ球菌の2成分性毒素γヘモリジンが形成するヘテロヘプタマー膜孔複合体の立体構造解析(蛋白質-構造,第47回日本生物物理学会年会)

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

    生物物理 49 S58-S59 2009年

    出版者・発行元:一般社団法人 日本生物物理学会

    DOI: 10.2142/biophys.49.S58_5  

︎全件表示 ︎最初の5件までを表示

MISC 43

  1. MRA画像を用いた脳底動脈形状の標準化

    北村洸, 麦倉俊司, 太田信, 安西眸

    日本機械学会バイオフロンティア講演会講演論文集(CD-ROM) 30th 1C15 2019年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebiofro.2019.30.1c15  

    ISSN:1348-2939

    eISSN:2424-2810

  2. Systematic review of hemodynamic discriminators for ruptured intracranial aneurysms

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

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

    出版者・発行元:特定非営利活動法人 日本バイオレオロジー学会

    DOI: 10.17106/jbr.33.53  

    ISSN:1867-0466

    詳細を見る 詳細を閉じる

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

  3. Hemodynamic Study on Coronary Artery Aneurysms with Bypass Surgery

    Haoran Wang, Hitomi Anzai, Makoto Ohta, Youjun Liu

    15th ICFD (Internatinal Conference of Fluid Dynamics) 2018年11月

  4. PIV MEASUREMENT IN AN IDEAL ANEURYSMAL MODEL USING A TRANSPARENT COIL MODEL 査読有り

    Makoto OHTA, Masanori KUZE, Simon TUPIN, Kaihong YU, Yasutomo SHIMIZU, Hitomi ANZAI

    Conference on Modelling Fluid Flow (CMFF’18) 2018年7月

  5. Dose hypertension history affect morphology or hemodynamic characteristics of Cerebrobasilar System? Retrospetive study of 249 patients diagnosed with hypertension. 査読有り

    Yujie Li, Mingzi Zhang, Ko Kitamura, Hitomi anzai, Shuji Mugikura, Makoto Ohta

    8th World Congress of Biomechanics 2018年7月

  6. Characteristics of Elasticity on Flow Behavior in Middle Cerebral Aneurysm Model 査読有り

    Ryuhei Yamaguchi, Gaku Tanaka, Taihei Kotani, Kahar Osman, Nadia Shafii, Hitomi Anzai, Makoto Ohta

    8th World Congress of Biomechanics 2018年7月

  7. Can morphology or haemodynamic characteristics of verteebrobasilar system be identifier of hypertension 査読有り

    Ko Kitamura, Yujie Li, Mingzi Zhang, Hitomi Anzai, Shuji Mugikura, Makoto Ohta

    8th World Congress of Biomechanics 2018年7月

  8. Multiobjective Optimization of Stent Design towards In-Stent Restenosis

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

    8th World Congress of Biomechanics 2018年7月

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

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

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

    出版者・発行元:一般社団法人 日本機械学会

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

    eISSN:2424-2810

  10. 冠動脈瘤治療における血流の数値流体力学解析

    安西 眸, 太田 信

    年次大会 2018 J0210303 2018年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmemecj.2018.j0210303  

    eISSN:2424-2667

  11. 脳動脈瘤抽出用ニューラルネットワークにおける,入力画像の表現方法の違いによる判定精度への影響

    渡邉和浩, 安西眸, JUCHLER Norman, HIRSCH Sven, BIJLENGA Philippe, 太田信

    バイオエンジニアリング講演会講演論文集(CD-ROM) 31st 2D14 2018年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebio.2019.31.2d14  

    ISSN:2424-2829

    eISSN:2424-2829

  12. 格子ボルツマン法を用いたステントストラット配置が脳動脈瘤内流れに与える影響の解析

    渡邉和浩, 安西眸, 太田信

    計算工学講演会論文集(CD-ROM) 23 4p 2018年

    出版者・発行元:日本計算工学会

    ISSN:1342-145X

  13. Location related variability of permeability characteristics in cancellous bone

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

    Proceedings of the 14th International Conference on Flow Dynamics 834-835 2017年11月

  14. 海綿骨内における浸透率測定

    伊藤誠, TUPIN Simon, 安西眸, 鈴木杏奈, 太田信

    日本バイオレオロジー学会誌(Web) 31 (2) 2017年

    ISSN:2186-5663

  15. 血管モデルの開発と動物実験

    太田信, 大西泰平, TUPIN Simon, 清水康智, 于凱鴻, 安西眸

    日本実験動物学会総会講演要旨集 64th 2017年

  16. 教育用,評価用,プレオペ用血管モデルの開発

    太田信, 清水康智, 于凱鴻, TUPIN Simon, 安西眸

    日本医学放射線学会秋季臨床大会抄録集 53rd 2017年

    ISSN:0048-0428

  17. フローダイバータステントを用いた脳動脈瘤治療に対する数値シミュレーションの応用

    張 明子, 李 玉潔, 安西 眸, 銭 逸, 太田 信

    年次大会 2017 (0) J0230204 2017年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmemecj.2017.J0230204  

    eISSN:2424-2667

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    <p>Intracranial aneurysms (IAs) account for a large portion of cerebrovascular disorders and can be treated with flow-diverting (FD) stents. To aid the treating clinicians with determination of a favourable treatment plan, we adopted numerical simulation methods to the optimisation of FD treatment, including the design optimisation of FD stent wire structure, as well as the optimisation of FD stent treatment procedure. Our simulation results suggest that both stent design and stent deployment may drastically affect the FD treatment outcomes; numerical simulation prior to the real treatment may therefore assist the treating clinicians in predicting the treatment outcomes.</p>

  18. 流量計と圧力センサを組み込んだインビトロモデルによるマルチレイヤーステントの評価

    テュパン シモン, 清水 康智, 安西 眸, 太田 信

    バイオエンジニアリング講演会講演論文集 2017 (0) 2B34 2017年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebio.2017.29.2B34  

    eISSN:2424-2829

  19. 低レイノルズ数領域における血液環流フローチャンバーシステムの開発

    安西眸, 白石泰之, 山家智之, 太田信

    日本バイオレオロジー学会誌(Web) 30 (2) 2016年

    ISSN:2186-5663

  20. AVEC CFD2016

    安西眸, TUPIN Simon, 渡邉和浩, RASHAD Sherif, 太田信

    日本バイオレオロジー学会誌(Web) 30 (2) 2016年

    ISSN:2186-5663

  21. 脳血管内治療デバイスと治療の有効性を予測する血管モデルの開発

    太田信, TUPIN Simon, 清水康智, 于凱鴻, 安西眸

    脳血管内治療(Web) 1 (Supplement) 2016年

    ISSN:2424-1709

  22. 血管内治療のための血管モデル開発

    太田信, 清水康智, TUPIN Simon, 大西泰平, 村元雄太, SEILLER Joanna, YU Kaihong, 安西眸

    日本機械学会年次大会講演論文集(CD-ROM) 2016 (0) W021003 2016年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmemecj.2016.W021003  

    ISSN:2424-2667

    eISSN:2424-2667

  23. 動脈瘤ネックの流入領域に対するストラットの相対位置が瘤内流れに与える影響

    渡邉和浩, 安西眸, 太田信

    バイオエンジニアリング講演会講演論文集(CD-ROM) 28th (0) _2F22-1_-_2F22-4_ 2016年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebio.2016.28._2F22-1_  

    ISSN:2424-2829

    eISSN:2424-2829

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    For the treatment of cerebral aneurysms, flow diverter (FD) stent placement has been attracted. To evaluate a positioning error of stent on aneurysm flow, we analyze an influence of strut positions with relation to the inflow zone. Lattice Boltzmann flow simulation was applied to compute flow velocity in 3-D ideal aneurysm with a curved parent artery. Rectangular solid as a strut model was placed along to the neck plane. The results suggest that the flow velocity in the aneurysm is effectively reduced when the flow in the aneurysm and parent vessel flow are separated by a strut.

  24. 脳動脈瘤の生化学的イベントと数値流体解析の応用に関するCutting-Edge

    安西眸, ZHANG Mingzi, PUTRA Narendra Kurnia, 渡邉和浩, 太田信

    脳血管内治療(Web) 1 (Supplement) S47(J‐STAGE) 2016年

    ISSN:2424-1709

  25. CFDで何をみるのか,見えるのか AVEC CFD2015

    安西眸, 下權谷祐児, 太田信, 八木高伸, 高尾洋之, 河野健一, 庄島正明

    日本バイオレオロジー学会年会プログラム・抄録集 38th 2015年

  26. 脳動脈瘤治療用ステントにおける自己組織化マップを用いた最適形状解析

    安西眸, 吉田裕貴, 下山幸治, 大林茂, 太田信

    日本機械学会年次大会講演論文集(CD-ROM) 2015 (0) _S0220301--_S0220301- 2015年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmemecj.2015._S0220301-  

    ISSN:2424-2667

    eISSN:2424-2667

    詳細を見る 詳細を閉じる

    As evaluation of hemodynamics in an aneurysm, a lot of parameters have been introduced. However, the relationship between stent geometry and each hemodynamic parameter is not clear enough. We applied Self-organizing Maps (SOM) to search the detailed relationship between stent strut and hemodynamic parameters. Two thousands of stent design candidates evaluated with five hemodynamic parameters and 25 stent geometry parameters were stored during the optimization process. By using SOM software, 2,000 design candidates were visualized into 30 2D-maps while preserving their own features in the original 30-dimensional design space. Each map was divided into 20 clusters to characterize stent design and flow reduction. By comparing each cluster, critical design for reduction effect of each hemodynamic parameter is suggested. Strut placement on the inflow area is important to reduce maximum shear rate. In addition to the inflow area, strut on the outflow area is required to reduce velocity, vorticity, and average shear rate.

  27. 実形状海綿骨内の数値流体力学解析

    佐久間 航, 中山 敏男, 安西 眸, 中村 修二, 佐渡 克行, 高川 浩和, 太田 信

    計算力学講演会講演論文集 2014 (27) 366-367 2014年11月22日

    出版者・発行元:一般社団法人日本機械学会

    ISSN:1348-026X

  28. 脳動脈瘤治療用ステントにおける数値解析を用いた最適設計—Optimization of stent design based on computational fluid dynamics study

    安西眸, Bastien Chopard, 太田信

    19 3p 2014年6月

  29. 実形状海綿骨内の数値流体力学解析

    佐久間航, 中山敏男, 安西眸, 中村修二, 佐渡克行, 高川浩和, 太田信

    日本機械学会計算力学講演会論文集(CD-ROM) 27th (0) 366-367 2014年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmecmd.2014.27.366  

    ISSN:2424-2799

    eISSN:2424-2799

  30. 脳動脈瘤内の血液凝固促進を目指したステントデザインの最適化

    吉田裕貴, 安西眸, 太田信

    日本機械学会最適化シンポジウム(CD-ROM) 11th (Web) 3p-_1204-3_ 2014年

    出版者・発行元:日本機械学会

    DOI: 10.1299/jsmeopt.2014.11.0__1204-1_  

    eISSN:2433-1295

  31. 脳動脈瘤治療用ステントにおける数値解析を用いた最適設計

    安西眸, CHOPARD Bastian, 中山敏男, ZHANG Mingzi, 吉田裕貴, 太田信

    計算工学講演会論文集(CD-ROM) 19 ROMBUNNO.D-3-2 2014年

    ISSN:1342-145X

  32. 脳血管内治療における数値流体力学~CFD(Computational Fluid Dynamics)の最前線~ステントの最適デザインを考える

    太田信, 安西眸, 吉田裕貴, ZHANG Mingzi, LI Yujie, 中山敏男

    脳神経外科速報 24 (5) 532-357 2014年

    ISSN:0917-1495

  33. 実形状動脈瘤を用いたステント形状最適化プログラム開発に関する研究

    安西眸, FALCONE Jean-Luc, CHOPARD Bastien, 太田信

    バイオエンジニアリング講演会講演論文集 25th (0) 535-536 2013年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebio.2013.25.535  

    ISSN:1348-2920

    eISSN:2424-2829

  34. 血流低減を目的とした脳動脈瘤用ステントデザインの最適設計

    太田信, 安西眸, 中山敏男

    理論応用力学講演会講演論文集(Web) 62nd (0) 200-200 2013年

    出版者・発行元:日本学術会議 「機械工学委員会・土木工学・建築学委員会合同IUTAM分科会」

    DOI: 10.11345/japannctam.62.0.200.0  

    詳細を見る 詳細を閉じる

    血管壁が瘤状に肥大化する病気である脳動脈瘤の治療法に血管内治療がある.近年ではステントと呼ばれる,動脈瘤内の血流を低減させ血栓化を促す医療デバイスが注目を集めている.現状のステントは親血管が血栓で塞栓する可能性が指摘されている.これに対して,近年では最適化と呼ばれる手法を用いて,高多孔率でありながら血流低減効果の高いステント形状の探索が行われている.しかしながらこれまでの研究において,最適化は多数の計算モデルを必要とすることから,微細なステント形状に適合した計算格子を作成するために作業者に大きな負担がかかることが指摘されていた.そこで著者らは理想形状動脈瘤に対し,格子ボルツマン法と擬似焼きなまし法を組み合わせることにより,ステント形状作成,計算格子生成,数値流体計算,血流低減効果の評価の一連の過程を自動化した,ステント形状最適化プログラムの開発を行い,自動化プロセスの有効性を示した.

  35. 医療デバイス周りの血流流体力学的見地からの血栓形成

    太田信, WETZEL S., 安西眸, 中山敏男, HAN Xiaobo, 清水康智, 小澤桂, 冨田典子

    日本バイオマテリアル学会シンポジウム予稿集 2012 2012年

  36. 格子ボルツマン法を用いた脳動脈瘤治療用ステントの形状最適化プログラムの開発

    安西眸, FALCONE Jean-Luc, CHOPARD Bastien, 太田信

    バイオエンジニアリング講演会講演論文集 24th (CD-ROM) (0) _7F24-1_-_7F24-2_ 2012年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebio.2012.24._7F24-1_  

    ISSN:1348-2920

    eISSN:2424-2829

  37. 脳動脈瘤用フローダイバータステントモデル化に対する圧力勾配と瘤内流れに関する研究

    三浦幸久, 安西眸, 中山敏男, 太田信

    日本機械学会東北支部総会・講演会講演論文集 47th (0) 20-21 2012年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmeth.2012.47.20  

    eISSN:2424-2713

  38. 脳動脈瘤に対するステントストラット位置の自動最適化に関する研究

    安西眸, FALCONE Jean-Luc, CHOPARD Bastien, 太田信

    日本機械学会年次大会講演論文集(CD-ROM) 2012 (0) _S021022-1-_S021022-3 2012年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmemecj.2012._S021022-1  

    ISSN:2424-2667

    eISSN:2424-2667

    詳細を見る 詳細を閉じる

    To produce an optimal design of stents for cerebral aneurysm is attracted for reducing the flow in the aneurysm efficiently. This report demonstrates the optimization for 3-D aneurysm with two different objectives. As the result, the optimum stent for the maximum velocity has denser struts on distal of the neck. On the other hand, the optimum stent for average velocity has denser struts on proximal of the neck.

  39. 血流数値解析の3次元可視化による効果的な脳動脈瘤ステント配置の予測

    安西眸, 中山敏男, 入江恵子, 太田信

    バイオエンジニアリング講演会講演論文集 23rd (0) 253-254 2011年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebio.2010.23.253  

    ISSN:1348-2920

    eISSN:2424-2829

  40. 未破裂脳動脈瘤の破裂リスクに関する3次元可視化システムを用いたCFD解析の試み

    入江恵子, 太田信, 安西眸, 中山敏男, 根來真, 廣瀬雄一

    日本バイオレオロジー学会年会プログラム・抄録集 34th 53 2011年

  41. ブドウ球菌の2成分性毒素γヘモリジンが形成するヘテロヘプタマー膜孔複合体の立体構築とサブユニット間配置の定量的解析

    冨田典子, 安西眸, 阿部和代, 金子淳, 神尾好是, 太田信

    日本農芸化学会大会講演要旨集 2010 2010年

  42. ブドウ球菌の2成分性毒素γヘモリジンが形成するヘテロヘプタマー膜孔複合体の立体構造解析

    冨田典子, 安西眸, 金子淳, 神尾好是, 太田信

    日本ブドウ球菌研究会プログラム・講演要旨集 54th 2009年

  43. 3次元可視化システムを用いた脳動脈瘤ステント周りの血流数値解析の可視化

    安西眸, 竹島由里子, 中山敏男, 太田信

    日本機械学会年次大会講演論文集 2009 (Vol.6) 177-178 2009年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmemecjo.2009.6.0_177  

    eISSN:2433-1325

    詳細を見る 詳細を閉じる

    The effect of stent on the flow reduction in cerebral aneurysm has been reported in CFD studies showing the stent position or the strut shape may affect the flow reduction. The 3D visualization may help easily to specify the inlet zone from parent artery to aneurysm and to find the relationship between the effective strut position and the flow pattern. Then we simulated adding a strut to a stent model on the inlet zone after specifying the zone using 3D visualization system. After moving the strut and repeating the visualization of results, we found a strut on the zone may reduce the flow into aneurysm effectively. The results may suggest the 3D visualization is useful for the assessment of strut position with effective reduction of flow into aneurysm.

︎全件表示 ︎最初の5件までを表示

書籍等出版物 1

  1. 基礎からよくわかる 実践的CFD(数値流体力学)入門 脳血管編

    山本 誠, 根本 繁, 髙尾 洋之

    メディカ出版 2017年3月24日

    ISBN: 4840461473

講演・口頭発表等 167

  1. オイラー液膜モデルを用いた下気道壁面からの微小飛沫生成シミュレーション 招待有り

    安西眸

    日本機械学会バイオエンジニアリング部門 制御と情報-生体への応用-研究会 2022年1月18日

  2. 数値流体解析を用いた気道内飛沫生成 シミュレーション 招待有り

    安西眸

    第4回 SDGs-ID 若手の会 2021年8月27日

  3. オイラー液膜モデルを用いた下気道モデルの飛沫シミュレーション~第一報臨界せん断応力に関する検討~

    進藤有悟, 森奈緒子, 麦倉俊司, 赤池孝章, 松永哲郎, 太田信, 安西眸

    統計数理研究所・東北大学流体科学研究所・材料高等研究所合同ワークショップ 2021年4月21日

  4. 脳血管確率アトラスに基づく脳血管自動ラベル付けプログラムの開発(第1報、中心線に基づく確率アトラスのラベル付け精度の評価)

    神 容慶, 北村 洸, 太田 信, 安西 眸, 麦倉 俊司, 森 菜緒子

    第54回 日本生体医工学会東北支部大会 2021年1月23日

  5. A study on Optical Flow Method for Hemodynamics Estimation

    Yutaro Kohata, Hitomi Anzai, Makoto Ohta, Meghane Decroocq, Carole Frindel, Simon RIT

    2ND INTERNATIONAL SYMPOSIUM ON COMPUTATIONAL BIOFLUID 2020 2020年12月16日

  6. The influence brought by specific boundary conditions on vascular simulations

    Fangjia Pan, Makoto Ohta, Hitomi Anzai, Shunji Mugikura, Naoko Mori

    2ND INTERNATIONAL SYMPOSIUM ON COMPUTATIONAL BIOFLUID 2020 2020年12月16日

  7. CFD analysis of AVF for hemodialysis

    Kazuki Takeda, Hitomi Anzai, Mingzi Zhang, Kohei Mitsuzuka, Wang Haoran, Ai Kajiyama, Makoto Ohta

    2ND INTERNATIONAL SYMPOSIUM ON COMPUTATIONAL BIOFLUID 2020 2020年12月16日

  8. Optimization of stent structure based on blood flow simulation 招待有り

    Hitomi Anzai, Mingzi Zhang, Narendra Kurnia Putra, Makoto Ohta

    2ND INTERNATIONAL SYMPOSIUM ON COMPUTATIONAL BIOFLUID 2020 2020年12月6日

  9. Implementation of Computer Simulation to Assess Flow−Diversion Treatment Outcomes— Systematic Review and Meta−Analysis 招待有り

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

    17th Interdisciplinary Cerebrovascular Symposium (ICS 2020) 2020年10月30日

  10. CFD Analysis of The Effect of Flush Flow Condition on Angiopscopy Visibility

    Kohei Mitsuzuka, Yujie Li, Toshio Nakayama, Hitomi Anzai, Wang Haoran, Makoto Ohta, Simon Tupin

    17th International Conference on Flow Dynamics 2020年10月30日

  11. 生体組織モデルを用いた医療機器開発へ参加のお誘い 招待有り

    太田 信, Tupin Simon, 安西 眸, 于 凱鴻, Zhang Mingzi, 戸塚 厚, 小助川博之

    第61回 日本脈管学会総会 2020年10月13日

  12. Implementation of Computer Simulation to Assess Flow−Diversion Treatment Outcomes — Systematic Review and Meta−Analysis 招待有り

    CFD-Bio, 日本機械学会バイオエンジニアリング部門 制御と情報-生体への応用研究会 脳神経血管内治療に関する医工学連携研究会 2020年10月5日

  13. Angiography-based velocimetry for blood flow

    Y. Kohata, H. Anzai, M. Decroocq, S. Rit, C. Frindel, Makoto Ohta

    Lyon Saint Etienne & Nippon Scientific Network Engineering sciences Lyon Tohoku LyonSE&N – ELyT Workshop 2020 2020年2月17日

  14. Flow Characteristics of Wall Elasticity in a Full-Scale patient-Specific Middle Cerebral Aneurysm

    Gaku Tanaka, Nadia S. Shafii, Gaku Takizawa, Tomoaki Yamazaki, Simon Tupin, Hitomi Anzai, Kahar Osman, Ryuhei Yamaguchi, Makoto Ohta

    The Nineteenth International Symposium on Advanced Fluid Information (AFI-2019) 2019年11月7日

  15. Influence of Input Patch Sizes on Results of a Convolutional Neural Network to Detect Cerebral Aneurysms from MRA Images

    Kazuhiro Watanabe, Hitomi Anzai, Norman Juchler, Sven Hirsch, Philippe Bijlenga, Makoto Ohta

    Sixteenth International Conference on Flow Dynamics 2019年11月7日

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

    Gaorang LI

    第29回バイオフロンティア講演会 2019年10月24日

  17. Simulation research on hemodynamic of surgery of coronary artery aneurysm

    Haoran WANG

    日本機械学会2018年度年次大会 2019年9月11日

  18. Pulse pattern classification of atherosclerotic patients based on convolutional neural network

    Gaoyang Li, Hitomi Anzai, Makoto Ohta

    UTM-IFS 1st Workshop 2019 2019年8月21日

  19. Physical and Virtual Arterial Models with Mechanical Properties for Mechanical Testing of Medical Device

    2019年8月21日

  20. MRA 画像を用いた脳底動脈形状の標準化

    北村洸,麦倉俊司,太田信,安西眸

    第30回バイオフロンティア講演会 2019年7月19日

  21. Computational Fluid Dynamics Analysis of Pial Arteriovenous Fistula

    Yutaro Kohata, Anzai Hitomi, Taichi Kin, Ohta Makoto

    6th International Conference on Computational and Mathematical Biomedical Engineering 2019年6月12日

  22. 3D Structure Standardization Of Cerebral Artery Using MRA Images For Classificattion

    Ko Kitamura, Shunji Mugikura, Makoto Ohta, Hitomi Anzai

    6th International Conference on Computational and Mathematical Biomedical Engineering 2019年6月12日

  23. MRA画像を用いた脳底動脈形状の標準化

    北村洸, 麦倉俊司, 太田信, 安西眸

    日本機械学会バイオフロンティア講演会講演論文集(CD-ROM) 2019年

  24. 脳動脈瘤抽出用ニューラルネットワークにおける,入力画像の表現方法の違いによる判定精度への影響

    渡邉和浩

    第31回バイオエンジニアリング講演会 2018年12月15日

  25. Hemodynamic Study on Coronary Artery Aneurysms with Bypass Surgery 国際会議

    Haoran WANG

    Fifteenth Internatinal Conference of Fluid Dynamics 2018年11月9日

  26. PIV MEASUREMENT IN AN IDEAL ANEURYSMAL MODEL USING A TRANSPARENT COIL MODEL 国際会議

    OHTA Makoto

    Conference on Modelling Fluid Flow (CMFF’18) The 17th International Conference on Fluid Flow Technologies 2018年9月4日

  27. Computational Fluid Dynamics Analysis to Predict Endothelial Cells Migration during Flow Exposure Experiment with Placement of Two Stent Wires 国際会議

    Narendra Kurnia Putra

    40th Annual International Conference of IEEE Engineering in Medicine and Biology Society 2018年7月17日

  28. Ko Kitamura, Yujie Li, Mingzi Zhang, Hitomi Anzai, Shuji Mugikura, Makoto Ohta 国際会議

    KITAMURA Ko

    8th World Congress of Biomechanics 2018年7月8日

  29. Multiobjective Optimization of Stent Design towards In-Stent Restenosis 国際会議

    Narendra Kurnia Putra

    8th World Congress of Biomechanics 2018年7月8日

  30. Can morphology or haemodynamic characteristics of verteebrobasilar system be identifier of hypertension

    Ko Kitamura, Yujie Li, Mingzi Zhang, Hitomi Anzai, Shuji Mugikura, Makoto Ohta

    8th World Congress of Biomechanics 2018年7月

  31. Characteristics of Elasticity on Flow Behavior in Middle Cerebral Aneurysm Model

    Ryuhei Yamaguchi, Gaku Tanaka, Taihei Kotani, Kahar Osman, Nadia Shafii, Hitomi Anzai, Makoto Ohta

    8th World Congress of Biomechanics 2018年7月

  32. Dose hypertension history affect morphology or hemodynamic characteristics of Cerebrobasilar System? Retrospetive study of 249 patients diagnosed with hypertension.

    Yujie Li, Mingzi Zhang, Ko Kitamura, Hitomi anzai, Shuji Mugikura, Makoto Ohta

    8th World Congress of Biomechanics 2018年7月

  33. PIV MEASUREMENT IN AN IDEAL ANEURYSMAL MODEL USING A TRANSPARENT COIL MODEL

    Makoto OHTA, Masanori KUZE, Simon TUPIN, Kaihong YU, Yasutomo SHIMIZU, Hitomi ANZAI

    Conference on Modelling Fluid Flow (CMFF’18) 2018年7月

  34. An application of deep learning technique for neurovascular research and future diagnosis 国際会議 招待有り

    安西 眸

    15th Interdisciplinary Cerebrovascular Symposium 2018年6月8日

  35. 格子ボルツマン法を用いたステントストラット配置が脳動脈瘤流れに与える影響の解析

    渡邉 和浩

    第23回計算工学講演会 2018年6月6日

  36. Correlation of CFD with enhancement 国際会議

    Hitomi Anzai, Norman Juchler, Makoto Ohta, Sven Hirsch, Philippe Bijlenga, Daniel A. Rüfenacht, Isabel Wanke

    international NeurovascularExploratoryWorkshop (iNEW) 2018年2月7日

  37. 格子ボルツマン法を用いたステントストラット配置が脳動脈瘤内流れに与える影響の解析

    渡邉和浩, 安西眸, 太田信

    計算工学講演会論文集(CD-ROM) 2018年

  38. Location related variability of permeability characteristics in cancellous bone

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

    Proceedings of the 14th International Conference on Flow Dynamics 2017年11月

  39. Automatic detection and localization of intracranial aneurysms by means of deep learning. 国際会議

    Kazuhiro Watanabe, Norman Juchler, Hitomi Anzai, Makoto Ohta, Sven Hirsch

    Deep Learning Day 2017 2017年9月22日

  40. ANALYSIS OF OPTIMAL STENT STRUCTURE FOR FLOW STAGNATION USING SELF-ORGANIZING MAPS 国際会議

    Hitomi Anzai, Yuuki Yoshida, Makoto Ohta

    5th Switzerland-Japan Workshop on Biomechanics 2017年9月14日

  41. 2D Vertex Model of Cell Monolayers and its Applications 国際会議

    Aziza Merzouki, Orestis Malasinas, Aurelien Roux, Anastasiya Trushko, Patrycja Paruch, Guillaume Rapin, Makoto Ohta, Hitomi Anzai, Athanasia Tzika, Mastien Chopard

    5th Switzerland-Japan Workshop on Biomechanics 2017年9月14日

  42. HOW TO FIND OUT OPTIMAL INTERVAL OF STRUTS FOR CEREBRAL ANEURYSM? 国際会議

    Kazuhiro Watanabe, Hitomi Anzai, Makoto Ohta

    5th Switzerland-Japan Workshop on Biomechanics 2017年9月14日

  43. 教育用、評価用、プレオペ用血管モデルの開発

    太田 信, 清水康智, 于 凱鴻, Simon Tupin, 安西 眸

    第53回日本医学放射線学会秋期臨床大会、特別企画「機能解析における数学的手法理解のために:数理分野と放射線科医の協働が織りなすハーモニー」 2017年9月10日

  44. 海綿骨内における浸透率測定

    伊藤誠, Simon Tupin, 安西眸, 鈴木杏奈, 太田信

    第40回日本バイオレオロジー学会年会 2017年5月27日

  45. 血管モデルの開発と動物実験

    太田 信, 大西泰平, Simon Tupin, 清水康智, 于 凱鴻, 安西 眸

    第64回日本実験動物学会総会、シンポジウム2「基盤的研究を医療現場に活かすための動物実験の役割」 2017年5月25日

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

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

    第56回日本生体医工学会大会 2017年5月3日

  47. Where does CFD identify lesion instability in small aneurysms? 国際会議

    Hitomi Anzai, Norman Juchler, Sven Hirsch, Makoto Ohta, Daniel R ̈ufenacht, Isabel Wanke

    5th International Conference on Computational & Mathmatical Biomedical Engineering 2017年4月10日

  48. Variation of strut parameter effects with wall deformation on stent 国際会議

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

    5th International Conference on Computational & Mathmatical Biomedical Engineering 2017年4月10日

  49. EC migration analysis by CFD with a strut in flow chamber 国際会議

    Makoto Ohta, Tomohito Watanabe, Xiaobo Han, Hitomi Anzai

    5th International Conference on Computational & Mathmatical Biomedical Engineering 2017年4月10日

  50. 流量計と圧力センサを組み込んだインビトロモデルによるマルチレイヤーステントの評価

    テュパン シモン, 清水康智, 安西眸, 太田信

    第29回バイオエンジニアリング講演会 2017年1月19日

  51. フローダイバータステントを用いた脳動脈瘤治療に対する数値シミュレーションの応用

    張 明子, 李 玉潔, 安西 眸, 銭 逸, 太田 信

    年次大会 2017年

    詳細を見る 詳細を閉じる

    <p>Intracranial aneurysms (IAs) account for a large portion of cerebrovascular disorders and can be treated with flow-diverting (FD) stents. To aid the treating clinicians with determination of a favourable treatment plan, we adopted numerical simulation methods to the optimisation of FD treatment, including the design optimisation of FD stent wire structure, as well as the optimisation of FD stent treatment procedure. Our simulation results suggest that both stent design and stent deployment may drastically affect the FD treatment outcomes; numerical simulation prior to the real treatment may therefore assist the treating clinicians in predicting the treatment outcomes.</p>

  52. 教育用,評価用,プレオペ用血管モデルの開発

    太田信, 清水康智, 于凱鴻, TUPIN Simon, 安西眸

    日本医学放射線学会秋季臨床大会抄録集 2017年

  53. 脳動脈瘤の生化学的イベントと数値流体解析の応用に関するCutting-Edge

    安西眸, Mingzi Zhang, Narendra Kurnia Putra, 渡邉和浩, 太田信

    神経血管内治療学会,機械学会バイオエンジニアリング部問共同研究会「脳神経血管内治療に関する医工学連携研究会」国際頭蓋内ステント学会共同シンポジウム 2016年11月26日

  54. Correlating MR Wall Enhancement and Wall Shear Stress: Does CFD work to predict aneurysm instability? 国際会議

    Hitomi Anzai, Norman Juchler, Makoto Ohta, Sven Hirsch, Daniel A. Rüfenacht, Isabel Wanke

    13th International IntraCranial Stent Meeting 2016年11月26日

  55. An Investigation on the Effect of Vessel Wall Deformation on Blood Flow and Wall Shear Stress along Stent Deployment Area 国際会議

    Narendra Kurnia Putra, Hitomi Anzai, Makoto Ohta

    13th International IntraCranial Stent Meeting 2016年11月26日

  56. Exploring the relationship between the inflow zone and strut positions within the aneurysm orifice: a hemodynamic simulation study 国際会議

    Kazuhiro Watanabe, Hitomi Anzai, Makoto Ohta

    13th International IntraCranial Stent Meeting 2016年11月26日

  57. BioModels 国際会議

    Makoto Ohta, Kaihong Yu, Simon Tupin, Yuta Muramoto, Hitomi Anzai, Yasutomo Shimizu

    3rd Biomedical Science and Technology Symposium (Macquarie-Tohoku Symposium) 2016年11月9日

  58. Stent Evaluation in vitro: Towards Next Generation of Biomodels 国際会議

    Simon TUPIN, Yasutomo SHIMIZU, Hitomi ANZAI, Kei TAKASE

    3rd Biomedical Science and Technology Symposium (Macquarie-Tohoku Symposium) 2016年11月9日

  59. Hemodynamic Behaviors under Blood Vessel Deformation by Stent Struts: Two Dimensional Study. 国際会議

    Narendra Kurnia Putra, Hitomi Anzai, Makoto Ohta

    Thirteenth International Conference on Flow Dynamics 2016年10月10日

  60. Comparison Study of Blood Flow Pattern Changes due to the Blood Vessel Deformation during Intravascular Stent Deployment 国際会議

    Narendra Kurnia Putra, Hitomi Anzai, Makoto Ohta

    TFC ELyT Workshop 2016 2016年10月6日

  61. 流れ中における内皮化促進のための表面処理に関する研究

    渡邊知仁, 小林尚俊, 韓笑波, 安西眸, 太田信

    日本流体力学会年会2016 2016年9月26日

  62. 血管内治療のための血管モデル開発

    太田 信, 清水康智, Simon Tupin, 大西泰平, 村元雄太, Joanna Seiller, 于 凱鴻, 安西 眸

    日本機械学会 2016 年度年次大会 2016年9月11日

  63. 力学的、熱力学的機能性を付与した生体組織モデル(バイオモデル)の開発と応用

    太田 信, 于 凱鴻, Simon Tupin, 清水康智, 安西 眸

    第12回東北大学 REDEEM シンポジウム 2016年9月10日

  64. Introduction of a flow rate and pressure controlled in vitro model to evaluate stent deployment effects to blood flow

    Simon TUPIN, Yasumoto SHIMIZU, Hitomi ANZAI, Kei TAKASE, Makoto OHTA

    東北大学-信州大学共催シンポジウム 2016年8月3日

  65. 低レイノルズ数領域における血液環流フローチャンバーシステムの開発

    安西眸, 白石泰之, 山家智之, 太田信

    第39回日本バイオレオロジー学会年会 2016年6月18日

  66. AVEC CFD 2016

    安西眸, Simon Tupin, 渡邉 和浩, Sherif Rashad, 太田信

    第39回日本バイオレオロジー学会年会 2016年6月18日

  67. 医療デバイス設計のための形状最適化とCFD

    第20回 流体科学におけるバイオ・医療に関する講演会 2016年6月15日

  68. 医療デバイス設計のための形状最適化とCFD

    第20回 流体科学におけるバイオ・医療に関する講演会 2016年6月15日

  69. Optimal Interval of two struts relative to aneurysm inflow 国際会議

    Hitomi Anzai, Kazuhiro Watanabe, Makoto Ohta

    VII European Congress on Computational Methods in Applied Sciences and Engineering 2016年6月5日

  70. Distribution on Endothelial Cells Downstream of a Stent Strut: An In-vitro Study 国際会議

    Makoto Ohta, Tomohito Watanabe, Xiaobo Han, Hisatoshi Kobayashi, Hitomi Anzai

    VII European Congress on Computational Methods in Applied Sciences and Engineering 2016年6月5日

  71. Endothelialization on NiTi wire with immobilization of collagen using HMDI 国際会議

    Tomohito Watanabe, Hisatoshi Kobayashi, Sho Matsumoto, Xiaobo Han, Hitomi Anzai, Makoto Ohta

    10th World Biomaterials Congress 2016年5月17日

  72. 動脈瘤ネックの流入領域に対するストラットの相対位置が瘤内流れに与える影響

    渡邉 和浩, 安西 眸, 太田 信

    第28回バイオエンジニアリング講演会 2016年1月9日

  73. 脳血管内治療デバイスと治療の有効性を予測する血管モデルの開発

    太田信, TUPIN Simon, 清水康智, 于凱鴻, 安西眸

    脳血管内治療(Web) 2016年

  74. AVEC CFD2016

    安西眸, TUPIN Simon, 渡邉和浩, RASHAD Sherif, 太田信

    日本バイオレオロジー学会誌(Web) 2016年

  75. Optimization of Flow Diverter design 国際会議

    Makoto Ito, Mingzi Zhang, Hitomi Anzai, Makoto Ohta

    Beijing-Tohoku Biomechanics Symposium 2015年11月25日

  76. Co-relationship between Hemodynamics and Optimal Stent Structure 国際会議

    Hitomi Anzai, Kazuhiro Watanabe, Yuuki Yoshida, Koji Shimoyama, Shigeru Obayashi, Makoto Ohta

    2nd Biomedical Symposium and 1st Biomedical Engineering Symposium 2015年11月16日

  77. Towards the Patient-specific Design of Intracranial Stents for Advanced Flow Diversion Efficacy 国際会議

    Mingzi Zhang, Hitomi Anzai, Bastien Chopard, Makoto Ohta

    2nd Biomedical Symposium and 1st Biomedical Engineering Symposium 2015年11月16日

  78. In-Vitro Model and Cell Behaviors 国際会議

    Makoto Ohta, Tomohito Watanabe, Xiaobo Han, Kaihong Yu, Taihei Onishi, Hitomi Anzai

    2nd Biomedical Symposium and 1st Biomedical Engineering Symposium 2015年11月16日

  79. Visualization of Flow Patterns through the Aneurysmal Orifice after Flow Diverter Optimizations with Different Objective Functions 国際会議

    Zhang M, Anzai H, Ohta M

    Interdisciplinary Cerebrovascular Symposium (Intracranial Stent Meeting 2015) 2015年11月13日

  80. Analysis of Relationship Between Stent Structure and Flow Stagnation Using Self-Organizing Maps for Realistic Aneurysm 国際会議

    Anzai H, Yoshida Y, Shimoyama K, Obayashi S, Ohta M

    Interdisciplinary Cerebrovascular Symposium (Intracranial Stent Meeting 2015) 2015年11月13日

  81. Cell density distribution around the wire with flow condition 国際会議

    Tomohito Watanabe, Han Xiaobo, Makoto Ohta, Hitomi Anzai, Hisatoshi Kobayashi

    The Fifteenth International Symposium on Advanced Fluid Information 2015年10月27日

  82. Development of a Program for Blood flow and Cell Behaviors Based on LBM Method (third report) 国際会議

    Makoto Ohta, Mingzi, Zhang, Bastien Chopard, Xiaobo Han, Yujie Li, Hitomi Anzai

    AFI-TFI 2015年10月27日

  83. 医療機器の開発に向けた海綿骨内の数値流体力学解析

    佐久間航, 中山敏男, 安西眸, 中村修二, 佐渡克之, Konstantin Kucher, Martin Geier, Manfred Krafczyk, 太田信

    東北大学-信州大学共催シンポジウム 2015年10月22日

  84. 平均および最大流速の最適脳動脈瘤用ステントデザイン

    張明子, 安西眸, 太田信

    流体力学会2015 2015年9月26日

  85. CFD Alanyses for the flow in Cancellous Bone with LBM 国際会議

    Wataru Sakuma, Toshio Nakayama, Hitomi Anzai, Shuji Nakamura, Katsuyuki Sado, Konstantin Kutscher, Martin Geier, Manfred Krafczyk, Makoto Ohta

    The 8th Asian-Pacific Conference on Biomechanics 2015年9月16日

  86. 脳動脈瘤治療用ステントにおける自己組織化マップを用いた最適形状解析

    安西眸, 吉田裕貴, 下山幸治, 大林茂, 太田信

    日本機械学会2015年度年次大会 2015年9月13日

  87. Introduction of Optimization of Design using Combination of Lattice Boltzmann Method as CFD and Simulated Annealing for Reduction of Flow Speed 国際会議

    Mingzi Zhang, Hitomi Anzai, Makoto Ohta

    1st NUAA-Tohoku University Joint Symposium on Fluid Science, Aerospace Engineering and Smart Structure Technology 2015年7月21日

  88. Searching for valuable hemodynamic parameters for applying to optimization study 国際会議

    Hitomi Anzai, Yuuki Yoshida, Mingzi Zhang, Makoto Ohta

    9th European Solid Mechanics Conference (ESMC 2015) 2015年7月6日

  89. Manufacture-Oriented Design Optimization for a Flow Diverter Stent Using Lattice Boltzmann Method and Simulated Annealing 国際会議

    Mingzi Zhang, Hitomi Anzai, Bastien Chopard, Makoto Ohta

    11th World Congress of Structural and Multidisciplinary Optimization (WCSMO-11) 2015年6月7日

  90. CFDで何をみるのか,見えるのか AVEC CFD 2015

    安西眸, 下權谷祐児, 太田信

    第38回日本バイオレオロジー学会年会 2015年6月6日

  91. Optimization of endovascular prosthesis for the treatment ofcerebral aneurysms 国際会議

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

    2015 ELyT lab Workshop,Feb18-21, 2015,Matsushima, Japan 2015年2月18日

  92. CFDで何をみるのか,見えるのか AVEC CFD2015

    安西眸, 下權谷祐児, 太田信, 八木高伸, 高尾洋之, 河野健一, 庄島正明

    日本バイオレオロジー学会年会プログラム・抄録集 2015年

  93. 脳動脈瘤内の血液凝固促進を目指したステントデザインの最適化

    吉田裕貴, 安西眸, 太田信

    第11回最適化シンポジウム2014 2014年12月12日

  94. 実形状海綿骨内の数値流体力学解析

    佐久間航, 中山敏男, 安西眸, 中村修二, 佐渡克行, 高川浩和, 太田信

    第27回計算力学講演会 2014年11月22日

  95. Automation of design optimization for intracranial stent

    First International Symposium for collaborative research between Tohoku University and Technische Universitat Braunschweig 2014年11月11日

  96. A Development of Manufacture-oriented Optimization Strategy for Flow Diverter Stent based on Cylindrical Spirals 国際会議

    Mingzi Zhang, Hitomi Anzai, Bastien Chopard, Makoto Ohta

    Eleventh International Conference on Flow Dynamics 2014年10月8日

  97. Development of a Program for Blood Flow and Cell Behaviors Based on LBM Method (Second report) 国際会議

    M. Ohta, S. Matsumoto, X. Han, B. Chopard, M. Zhang, Y. Li, Y. Yoshida, H. Anzai

    Eleventh International Conference on Flow Dynamics 2014年10月8日

  98. Modeling of Cortical Bone and Bone Marrow 国際会議

    M. Ohta, W. Sakuma, Y. Muramoto, H. Anzai, T. Nakayama

    Eleventh International Conference on Flow Dynamics 2014年10月8日

  99. Optimization of stent design for intracranial aneurysm 国際会議

    Hitomi Anzai, Yuuki Yoshida, Makoto Ohta

    The Fourth Japan-Switzerland Workshop on Biomechamics (JSB2014) 2014年9月1日

  100. Development of Image Guided Minimal Invasive Treatments 国際会議

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

    The Fourth Japan-Switzerland Workshop on Biomechamics (JSB2014) 2014年9月1日

  101. An Optimization Method of FD Stent for Cerebral Aneurysm facing tne Stent Design and Manufacturing Needs 国際会議

    Mingzi Zhang, Hitomi Anzai, Bastien Chopard, Makoto Ohta

    The Fourth Japan-Switzerland Workshop on Biomechamics (JSB2014) 2014年9月1日

  102. The concept of Bundle of Inflow (BOI) for reducing flow in aneurysm 国際会議

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

    7th World Congress of Biomechanics (WCB2014) 2014年7月6日

  103. Manufacture-oriented Struts Structure Optimization of Flow Diverter for Intracranial Aneurysm 国際会議

    Mingzi Zhang, Hitomi Anzai, Makoto Ohta

    7th World Congress of Biomechanics (WCB2014) 2014年7月6日

  104. 脳動脈瘤治療用ステントにおける数値解析を用いた最適設計

    安西眸, Bastien Chopard, 中山敏男, 張明子, 吉田裕貴, 太田信

    第19回計算工学講演会 2014年6月11日

  105. Analysis of optimized design of stent 国際会議

    Interdisciplinary Cerebrovascular Symposium, ICS2014 2014年6月2日

  106. Introduction of Design Optimization for Intracranial Stent 国際会議

    Hitomi Anzai, Makoto Ohta

    2nd Core-to-Core Workshop "Japan-China Joint Workshop on Bio, Material and Flow Dynamics" 2014年2月27日

  107. 血流数値解析に基づくステントデザインに関する研究

    信州大学・東北大学共催シンポジウム 2014年2月27日

  108. 脳血管内治療における数値流体力学~CFD(Computational Fluid Dynamics)の最前線~ステントの最適デザインを考える

    太田信, 安西眸, 吉田裕貴, ZHANG Mingzi, LI Yujie, 中山敏男

    脳神経外科速報 2014年

  109. 血流低減のためのステント形状探索に関する研究

    産業技術総合研究所ライフサイエンス研究分野治療技術支援グループ研究セミナー 2013年12月18日

  110. A Study on Multiscale Model in the presence of Systemic-to-Pulmonary Shunt utilizing LBM-LPM 国際会議

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

    The 5th Asia Pacific Congress on Computational Mechanics (APCOM2013) 2013年12月11日

  111. Hemodynamic Numerical Simulation in Artery Complicated with both Stenosis and Aneurysm in Different Shape and Position 国際会議

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

    The 5th Asia Pacific Congress on Computational Mechanics (APCOM2013) 2013年12月11日

  112. Optimized Stent 国際会議

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

    Tenth International Conference on Flow Dynamics 2013年11月25日

  113. Development of a Program for Blood flow and Cell Behaviors Based on LBM Method 国際会議

    Makoto Ohta, Bastien Chopard, Hitomi Anzai

    Tenth International Conference on Flow Dynamics 2013年11月25日

  114. Optimization of stent design to increase the porosity 国際会議

    Yuuki Yoshida, Hitomi Anzai, Makoto Ohta

    12th Congress World Federation of Interventional and Therapeutic Neuroradiology 2013年11月9日

  115. Optimization of blood flow for intracranial stent 国際会議

    Makoto Ohta, Hitomi Anzai, Han Xiaobo

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

  116. Application of optimization for design of intracranial stent with blood flow reduction as objective function 国際会議

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

    World Congress on Structural and Multidisciplinary Optimization 2013年5月19日

  117. 血流低減を目的とした脳動脈瘤ステントデザインの最適設計

    太田信, 安西眸, 中山敏男

    第62回応用力学講演会 2013年3月6日

  118. 実形状動脈瘤を用いたステント形状最適化プログラム開発に関する研究

    安西眸, Jean-Luc Falcone, Basten, Chopard, 太田信

    第25回バイオエンジニアリング講演会 2013年1月9日

  119. 血流低減を目的とした脳動脈瘤用ステントデザインの最適設計

    太田信, 安西眸, 中山敏男

    理論応用力学講演会講演論文集(Web) 2013年

    詳細を見る 詳細を閉じる

    血管壁が瘤状に肥大化する病気である脳動脈瘤の治療法に血管内治療がある.近年ではステントと呼ばれる,動脈瘤内の血流を低減させ血栓化を促す医療デバイスが注目を集めている.現状のステントは親血管が血栓で塞栓する可能性が指摘されている.これに対して,近年では最適化と呼ばれる手法を用いて,高多孔率でありながら血流低減効果の高いステント形状の探索が行われている.しかしながらこれまでの研究において,最適化は多数の計算モデルを必要とすることから,微細なステント形状に適合した計算格子を作成するために作業者に大きな負担がかかることが指摘されていた.そこで著者らは理想形状動脈瘤に対し,格子ボルツマン法と擬似焼きなまし法を組み合わせることにより,ステント形状作成,計算格子生成,数値流体計算,血流低減効果の評価の一連の過程を自動化した,ステント形状最適化プログラムの開発を行い,自動化プロセスの有効性を示した.

  120. Optimal Design of Flow Diverter Stent Associated with Inflow ZonesStent designs for efficient reduction of intra-aneurismal flow with various aneurysms 国際会議

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

    GRADUATE SEMINAR SPONSORED BY: MECHANICAL ENGINEERING and MATERIALS SCIENCE 2012年10月11日

  121. Flow analysis of stenosis and aneurysm using hydrogel for comparison to computational simulation 国際会議

    Makoto Ohta, Toshio Nakayama, Hitomi Anzai

    GRADUATE SEMINAR SPONSORED BY: MECHANICAL ENGINEERING and MATERIALS SCIENCE 2012年10月11日

  122. Stent designs for efficient reduction of intra-aneurismal flow with various aneurysms 国際会議

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

    The 9th International IntraCranial Stent Meeting (ICS) 2012年10月8日

  123. Modeling Flow Diverter Stent using Porous Media 国際会議

    Makoto Ohta, Yukihisa Miura, Hitomi Anzai, Toshio Nakayama

    The 9th International IntraCranial Stent Meeting (ICS) 2012年10月8日

  124. 医療デバイス周りの血流流体力学的見地からの血栓形成

    太田信, Stephan G. Wetzel, 安西眸, 中山敏男, 韓笑波, 清水康智, 小澤桂, 冨田典子

    日本バイオマテリアル学会大会シンポジウム2012 2012年9月26日

  125. Characterization of Design of Stent Strut Positioning using LBM Method 国際会議

    Makoto Ohta, Bastien Chopard, Hitomi Anzai

    the Twelfth International Symposium on Advanced Fluid Information and Transdisciplinary Fluid Integration (AFI/TFI) 2012年9月19日

  126. Measurement of Pressure Drop for Modeling Intracranial Flow Diverter Stent Using Porous Medium 国際会議

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

    Ninth International Conference on Flow Dynamics 2012年9月19日

  127. Measurement of Pressure Drop for Modeling Intracranial Flow Diverter Stent Using Porous Medium 国際会議

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

    Optimum Design of Flow Diverter Stent Associated with Arterial Geometries 2012年9月19日

  128. Simulation of Hemodynamics in Artery with Aneurysm and Stenosis 国際会議

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

    Optimum Design of Flow Diverter Stent Associated with Arterial Geometries 2012年9月19日

  129. A Development of Lattice Boltzmann Model and Lumped Parameter Model Connection for Cardiovascular Multiscale Analysis 国際会議

    Mingzi Zhang, Hitomi Anzai, Youjun Liu, Makoto Ohta

    Optimum Design of Flow Diverter Stent Associated with Arterial Geometries 2012年9月19日

  130. 脳動脈瘤に対するステントストラット位置の自動最適化に関する研究

    安西眸, Jean-Luc Falcone, Basten, Chopard, 太田信

    日本機械学会2012年度年次大会 2012年9月9日

  131. Optimization of Intracranial Stent for Rducing Flow Using Lattice Boltzmann Method 国際会議

    Makoto Ohta, Hitomi Anzai

    2012 Beijing International Symposium on Biomechanics 2012年9月3日

  132. The Design Characteristics Extracted from an Optimal Flow Diverter in an Ideal Side-wall Aneurysm Using Lattice Boltzmann Method 国際会議

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

    8th European Solid Mechanics Conference 2012年7月9日

  133. 脳動脈瘤用フローダイバータステントモデル化に対する圧力勾配と瘤内流れに関する研究

    三浦幸久, 安西眸, 中山敏男, 太田信

    日本機械学会東北支部第47期総会・講演会 2012年3月13日

  134. 格子ボルツマン法を用いた脳動脈瘤治療用ステントの形状最適化プログラムの開発

    安西眸, Jean-Luc Falcone, Basten, Chopard, 太田信

    日本機械学会第24回バイオエンジニアリング講演会 2012年1月7日

  135. Effect of Initial Conditions of Stent Geometry on Optimized Design of Flow Diverters 国際会議

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

    the Eleventh International Symposium on Advanced Fluid Information and Transdisciplinary Fluid Integration (AFI/TFI) 2011年11月9日

  136. Visualization leads Endovascular Treatments of Cerebral Aneurysm

    Makoto Ohta, Hitomi Anzai, Yasutomo Shimizu, Shuya Shida, Kei Ozawa, Cahang -ho Yu, Hiroyuki Kosukegawa, Xiaobo Han, Noriko Tomita, Toshio Nakayama

    2011年度 上智大学理工学部 日本SGI株式会社寄付講座 「ビジュアリゼーション(科学技術における応用)II」 2011年10月20日

  137. Development of the design of flow diverters using automated optimization based on lattice Boltzmann method 国際会議

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

    8th International Interdisciplinary cerebrovascular Symposium and 11th Oriental Conference of Interventional Neuroradiology and 6th East Asian Conference of Neurointervention 2011年9月8日

  138. Study on Effect of Blood Flow Reducing by Stent 国際会議

    Yukihisa Miura, Toshio Nakayama, Hitomi Anzai, Makoto Ohta

    8th International Interdisciplinary cerebrovascular Symposium and 11th Oriental Conference of Interventional Neuroradiology and 6th East Asian Conference of Neurointervention 2011年9月8日

  139. 未破裂脳動脈瘤の破裂リスクに関する3次元可視化システムを用いたCFD解析の試み

    入江恵子, 太田信, 安西眸, 中山敏男, 根來真, 廣瀬雄一

    第34回日本バイオレオロジー学会年会 2011年6月3日

  140. Porous Mediumを用いた脳動脈瘤用フローダイバータステントのモデル化に関する検証

    三浦幸久, 中山敏男, 安西眸, 太田信

    第7回生体工学と流体工学に関するシンポジウム 2011年3月3日

  141. 未破裂脳動脈瘤の破裂リスクに関する3次元可視化システムを用いた経時的なCFD解析の試み

    入江恵子, 根來 眞, 太田 信, 中山敏男, 安西眸, 廣瀬雄一, 松井俊和

    第40回日本神経放射線学会 2011年2月24日

  142. 未破裂脳動脈流の破裂リスクに関する3次元可視化システムを用いた経時的なCFD解析の試み

    入江恵子, 太田信, 中山敏男, 安西眸, 廣瀬雄一, 松井俊和

    第34回日本脳神経CI学会総会 2011年2月4日

  143. 血流数値解析の3次元可視化による効果的な脳動脈瘤ステント配置の予想

    安西眸, 中山敏男, 入江恵子, 太田信

    日本機械学会, 第23回バイオエンジニアリング講演会 2011年1月8日

  144. 血流数値解析の3次元可視化による効果的な脳動脈瘤ステント配置の予測

    安西眸, 中山敏男, 入江恵子, 太田信

    バイオエンジニアリング講演会講演論文集 2011年

  145. フローダイバーターの脳動脈瘤ステント設計

    太田信, 安西眸, 中山敏男, Chang-ho Yu

    SMAシンポジウム2010 2010年11月26日

  146. Numerical analisys of blood flow around intracranial stent using 3-d visualization 国際会議

    Hitomi Anzai, Toshio Nakayama, Keiko Irie, Makoto Ohta

    Swiss-Japanese Scientific seminar 2010年11月15日

  147. The Effect of Computational Simulation on Endovascular Treatments of Cerebral Aneurysm

    Makoto Ohta, Kenjiro Okuno, Hitomi Anzai, Toshio Nakayama

    2010年度 上智大学理工学部総合講座「ビジュアリゼーション(科学技術における応用)II」 2010年11月4日

  148. Analyzing Blood Flow in Bifurcated Artery with Cerebral Aneurysm using Two Stents 国際会議

    Hitomi Anzai, Toshio Nakayama, Keiko Irie, Makoto Ohta

    Seventh International Conference on Flow Dynamics 2010年11月1日

  149. 黄色ブドウ球菌γヘモリジンが形成するヘテロヘプタマー膜孔複合体におけるサブユニット配置解析 Subunit arrangement analysis of staphylococcal γ-hemolysin heteroheptameric transmembrance pore

    Noriko Tomita, Kazuyo Abe, Hitomi Anzai, Makoto Ohta

    日本生物物理学会 第48回年会 2010年9月20日

  150. Computational Design of Intracranial Stent Using 3D Visualization System 国際会議

    Makoto Ohta, Hitomi Anzai, Toshio Nakayama

    Live International Neuroradiology Conference (Inconjunction with the 7th ICS) 2010年8月13日

  151. Analysis of Three-Dimensional Structure and Subunit Mismatch in Staphylococcal γ-Hemolysin Heteroheptameric Transmembrane Pore 国際会議

    Noriko Tomita, Hitomi Anzai, Kazuyo Aba, Makoto Ohta

    Microscopy and Microanalysis 2010年8月1日

  152. Molecular Architecture Analysis of Staphylococcalγ-hemolysin Heteroheptameric Transmembrane Pore: Construction of Three-dimensional Structure with Subunit Arrangement Mismatch Based on High-resolution Electron Microscopic Image 国際会議

    Noriko Tomita, Hitomi Anzai, Kazuyo Aba, Makoto Ohta

    6th World Congress of Biomechanics 2010年8月1日

  153. Simulations of Endovascular Treatment for Cerebral Aneurysm 国際会議

    Makoto Ohta, Kaoru Matsumoto, Syuya Shida, Chihaya Kiyomitsu, Hiroyuki Kosukegawa, Noriko Tomita, Chang-ho Yu, Hitomi Anzai, Toshio Nakayama, Anne M. Robertson

    6th World Congress of Biomechanics 2010年8月1日

  154. 脳動脈用ステントにおける流体力学的理論解析の試み

    太田信, 安西眸, 中山敏男

    第16回日本血管内治療学会総会 2010年7月23日

  155. Computational Simulation of Intracranial Stent using 3D visualization system 国際会議

    Makoto Ohta, Hitomi Anzai, Toshio Nakayama

    SIRIC International Symposium 2010 2010年7月2日

  156. ブドウ球菌の2成分性毒素γヘモリジン膜孔複合体における分子配置解析と立体構造予測

    ブドウ球菌の, 成分性毒素, ヘモリジン膜孔複合体における分子配置解析と立体構造予測

    日本顕微鏡学会 第66回学術講演会 2010年5月23日

  157. ブドウ球菌の2成分性毒素γヘモリジンが形成するヘテロヘプタマー膜孔複合体の立体構造とサブユニット間配置の定量的解析

    冨田典子, 安西眸, 阿部和代, 金子淳, 神尾好是, 太田信

    日本農芸化学学会2010年度大会 2010年3月28日

  158. ブドウ球菌の2成分性毒素γヘモリジンが形成するヘテロヘプタマー膜孔複合体の立体構築とサブユニット間配置の定量的解析

    冨田典子, 安西眸, 阿部和代, 金子淳, 神尾好是, 太田信

    日本農芸化学会大会講演要旨集 2010年

  159. Three-dimensional structure analysis of staphylococcal γ-hemolysin heteroheptameric transmembrance pore complex

    Noriko Tomita, Hitomi Anzai, Yoshiyuki Kamio, Makoto Ohta

    日本生物物理学会第47回年会講演 2009年10月31日

  160. ブドウ球菌の2成分性毒素γヘモリジンが形成するヘテロへプタマー膜孔複合体の立体構造解析

    冨田典子, 安西眸, 金子淳, 神尾好是, 太田信

    日本ブドウ球菌研究会 2009年9月17日

  161. 3次元可視化装置を用いた脳動脈瘤ステント周りの血流数値解析の可視化

    安西眸, 竹島由里子, 中山敏男, 太田信

    日本機械学会 2009年度年次大会 2009年9月13日

  162. 3D Visualization of Numerical Simulation of Blood Flow on Intracranial Stent

    Hitomi Anzai, Yuriko Takeshima, Toshio Nakayama, Makoto Ohta

    Third Switzerland-Japan workshop on Biomechanics 2009(SJB 2009) 2009年9月1日

  163. Molecular architecture analysis of Staphylococcal γ-hemolysin heteroheptameric transmembrane pore complex

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

    Third Switzerland-Japan workshop on Biomechanics 2009(SJB 2009) 2009年9月1日

  164. 3rd Virtual Intracranial Stenting Challenge(VICS09) 国際会議

    Makoto Ohta, Toshio Nakayama, Hitomi Anzai, Juan R. Cebral, Luca Augsburger

    International Intracranial Stent Meeting 2009: Virtual Intracranial Stent Challnege 2009 2009年8月5日

  165. 3D Visualization of numerical simulation of blood flow on intracranial stent

    Hitomi Anzai, Yuriko Takeshima, Toshio Nakayama, Makoto Ohta

    International Intracranial Stent Meeting 2009 2009年8月5日

  166. 黄色ブドウ球菌の2成分血球崩壊毒素γヘモリジンが形成する膜孔複合体の立体構造解析

    冨田典子, 安西眸, 金子淳, 神尾好是, 太田 信

    日本顕微鏡学会第65回学術講演会 2009年2月21日

  167. 3次元可視化システムを用いた脳動脈瘤ステント周りの血流数値解析の可視化

    安西眸, 竹島由里子, 中山敏男, 太田信

    日本機械学会年次大会講演論文集 2009年

    詳細を見る 詳細を閉じる

    The effect of stent on the flow reduction in cerebral aneurysm has been reported in CFD studies showing the stent position or the strut shape may affect the flow reduction. The 3D visualization may help easily to specify the inlet zone from parent artery to aneurysm and to find the relationship between the effective strut position and the flow pattern. Then we simulated adding a strut to a stent model on the inlet zone after specifying the zone using 3D visualization system. After moving the strut and repeating the visualization of results, we found a strut on the zone may reduce the flow into aneurysm effectively. The results may suggest the 3D visualization is useful for the assessment of strut position with effective reduction of flow into aneurysm.

︎全件表示 ︎最初の5件までを表示

共同研究・競争的資金等の研究課題 14

  1. 患者固有の脳動脈瘤内血流に対する弾性壁の効果

    山口 隆平, 太田 信, 田中 学, 安西 眸

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research

    研究種目:Grant-in-Aid for Scientific Research (C)

    研究機関:Tohoku University

    2022年4月1日 ~ 2025年3月31日

  2. 数理的血管分岐パターン分類と血管走行標準化による動脈瘤発生予測モデルの確立

    森 菜緒子, 麦倉 俊司, 太田 信, 安西 眸, 北村 洸

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research

    研究種目:Grant-in-Aid for Scientific Research (C)

    研究機関:Tohoku University

    2022年4月1日 ~ 2025年3月31日

  3. 脳形態画像に基づく3次元血流場推定ネットワークの開発

    安西 眸, 麦倉 俊司, 杉山 慎一郎, 森 菜緒子

    2022年4月1日 ~ 2025年3月31日

  4. 血流解剖に基づく未破裂脳動脈瘤分類および新規画像診断システムの提案

    杉山 慎一郎, 新妻 邦泰, 安西 眸, 船本 健一

    2022年4月1日 ~ 2025年3月31日

  5. MRA血管走行・壁ストレス標準モデルを用いた脳卒中リスクの可視化

    麦倉 俊司, 太田 信, 安西 眸, 森 菜緒子

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)

    研究種目:Grant-in-Aid for Scientific Research (C)

    研究機関:Tohoku University

    2021年4月1日 ~ 2024年3月31日

    詳細を見る 詳細を閉じる

    脳卒中はリスクファクターとして性別,人種,遺伝子,高血圧,糖尿病,脂質異常,加齢があげられている.MRIはイベントが発症してから出血や梗塞の範囲,閉塞血管を評価し,治療方針や予後を決定するために用いられているが,イベント発症前のリスク評価は行われていない.我々は,MR angiography(MRA)をMontreal Neurological Institute (MNI)templateにより標準座標へ変換することにより血管走行位置座標を標準化し,さらに血管の中心点を抽出し分岐点を同定することにより,標準座標上の血管走行を抽出する技術を開発した.本研究の目的は,脳卒中リスクをMRA画像により可視化することである.具体的には,1) 大規模地域住民コホートを用い,各年代の血管走行・壁ストレス標準モデルを作成する.2)モデルからの逸脱に関連する遺伝子,性別,年齢,生活習慣などの要因を明らかにし,脳卒中リスクファクターを定量化する.3)ラット高血圧モデルにおいて血管走行・壁ストレス変化を確認する.我々は,脳卒中発症前リスクを可視化することを目的に,医療技術,大規模コホート研究,工学技術の3つを融合させることにより,血管走行・壁ストレス標準モデルを作成する.本技術により,血管走行・壁ストレス標準モデルを作成し,脳卒中リスクを可視化し,更にラット高血圧モデルにおいてMRAを撮像し,確認する.

  6. 血液透析シャント狭窄を防ぐ埋込型デバイスの研究開発

    梶山 愛, 木下 知, 鈴木 智之, 太田 信, 安西 眸, 片平 晋太郎

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)

    研究種目:Grant-in-Aid for Scientific Research (C)

    研究機関:Tohoku University

    2021年4月1日 ~ 2024年3月31日

    詳細を見る 詳細を閉じる

    本年度の研究目標は、慢性期動物実験(雌ビーグル犬1匹)を以下の①②③④の手順で実施し、デバイスの基礎的な安全性及び有効性の評価を行うことで、デバイスのコンセプト検証を行うことである。 ①デバイス製作(担当:梶山):現状のデバイスをもとにして透析専門医(弘前大学病院泌尿器科)の協力を得ながら、装着時ユーザビリティを考慮した設計を行った。材料は熱硬化性ポリウレタンエラストマーを使用し、(株)KobeWaposにて製造を行った。 ②シャント造設手術:東北大学医学部附属動物実験施設にて、同大学病院心臓血管外科とともに、ビーグル犬の左大腿動静脈には従来の鋭角吻合形状シャントを、右大腿動静脈にはデバイスを装着した鈍角吻合形状シャントを作製した。この時、デバイス留置による血管および周囲組織の破損は確認されなかったため、留置時の安全性には問題ないと分かった。 ③造影CT撮像によるWall shear stress値算出:シャント作製直後および作製2週間後において、左右シャント部分の造影CT撮像を行う(東北大学医学部保健学科協力)ことで、シャントの3次元データを取得し、流体シミュレーションソフトAnsysを用いてシャント吻合部におけるwall shear stres値を算出した。その結果、従来シャントのみにおいてシャント吻合部で異常なwall shear stressが発生しており、シャント狭窄が最も多く発生する箇所と一致した。 ④シャント組織の摘出・病理観察:シャント造設後2週間後安楽死処置を行った上で、左右のシャント組織の抽出を行い、血管断面の病理観察を行った。その結果、③にてwall shear stressが発生した場所において狭窄(内膜肥厚)が始まっていたため、シャント内で発生するwall shear stressは狭窄の要因であることが示唆された。

  7. 3Dプリンタ用PVA材料の構造および熱物性と適応部位の解明

    太田 信, 岡本 吉弘, 安西 眸, 庄島 正明, TUPIN SIMON

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

    研究種目:Grant-in-Aid for Scientific Research (B)

    研究機関:Tohoku University

    2020年4月1日 ~ 2023年3月31日

  8. 脳動脈瘤の進展・破裂抑止と弾性壁効果

    山口 隆平, 田中 学, 太田 信, TUPIN SIMON, 安西 眸

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)

    研究種目:Grant-in-Aid for Scientific Research (C)

    研究機関:Tohoku University

    2019年4月1日 ~ 2022年3月31日

    詳細を見る 詳細を閉じる

    脳動脈瘤の進展・破裂の予測精度を向上させるため、本来柔軟な瘤壁の弾性の影響を検討すべく、薄膜弾性の小さな脳動脈瘤を十分に再現できる作製法を確立した。この薄膜弾性の実寸 Phantom modelと、セットする最適なBathの組合せを再現できた。この研究の主要なポイントは、血管壁と同じ弾性係数を持つ直径7~10mm程度の透明な実動脈瘤 Phantomの作製である。この確立により、血流の拍動に伴う膨張・収縮変形の再現が可能となった。測定項目は、動脈瘤の進展、破裂に至る血行力学的因子である壁せん断応力WSS(Wall Shear Stress)、壁せん断応力の空間勾配 WSSG (Gradient of WSS)、流れの不安定性(Flow Instability)、また計算流体力学CFD(Computational Fluid Dynamics)による瘤底部での淀みに伴う血流の滞留時間 RRT(Residual Residence Time)の実験・解析した。 WSSの瘤壁に沿う勾配(WSSG)が淀み点回りで極めて大きくなること、この効果を調査するため、剛体モデルも作製した。対象となる中大脳動脈瘤である。WSSの抑制と、瘤入口から瘤底部に衝突する淀み点回りで、WSSの瘤壁に沿う勾配 (WSSG) が極めて大きくなることから、淀み点回りに作用するTensile forceが破裂の一因になる。さらに、剛体と弾性壁モデルでは、低レイノルズ数の拍動に伴うFlow Instability の指標の一つである運動エネルギ減衰率(KEC: Kinetic Energy Cascade)が、低周波及び高周波数域で弾性壁の減少勾配と減衰率は 10^-1~10^-2と大きく減衰すること。Flow Instabilityは剛体壁に限定され、弾性を考慮した実験は少なく、解析法はない。

  9. 飛沫発生シミュレーションによる新型コロナオ ミックス予測の開発 -新型コロナオミックスと サブミクロン流体力学を基盤としたエアロゾル 飛沫及び吸着シミュレーションの開発-

    安西 眸, 高奈 秀匡, 早川 晃弘, 大林 茂, 太田 信, 赤池 孝章, 松永 哲郎

    2021年9月 ~ 2022年3月

  10. 数値流体力学解析とMRI炎症マッピングによる脳動脈瘤成長メカニズムの解明 競争的資金

    安西 眸

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Early-Career Scientists

    研究種目:Grant-in-Aid for Early-Career Scientists

    研究機関:Tohoku University

    2018年4月1日 ~ 2021年3月31日

    詳細を見る 詳細を閉じる

    本研究では核磁気共鳴画像法(MRI)における増強効果と血流ストレスの結び付けを行うため、増強効果が見られた小型~中型動脈瘤について画像解析および数値流体力学解析(CFD)を行った。特に10年のフォローアップを行ったケースでは、ブレブ発生位置に炎症が見られ、ブレブ方向への動脈瘤伸張が見られた。より大規模な患者群に解析を適用するため、深層学習ネットワークを構築し、血管形状から直接流れ場を推定するシステムを構築した。本システムを使うことでCFDを行うより大幅に血流解析速度が向上し、より大規模な患者群に対して血流解析を行い、動脈瘤の発生・進展・破裂に関する血流パラメータの統計解析を行える可能性を得た。

  11. 動脈瘤壁の治癒と穿通枝温存を両立する紡錘状動脈瘤治療用ステントの開発

    遠藤 英徳, 太田 信, 仲井 正昭, 荒船 龍彦, 安西 眸, 大谷 清伸

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)

    研究種目:Grant-in-Aid for Scientific Research (C)

    研究機関:Tohoku University

    2017年4月1日 ~ 2020年3月31日

    詳細を見る 詳細を閉じる

    紡錘状脳動脈瘤の臨床例に対して、流体力学解析を行い、動脈瘤の壁におけるストレスデータの標準化を行った。続いて、流体工学的に動脈瘤壁から出血を起こしにくい条件、しかも、動脈瘤から分岐する細血管の開存が維持される条件を算出し、ステントデザインを検討した。さらに、プロトタイプのステントを用いて、ブタ紡錘状動脈瘤モデルに留置した場合に内部を流入する血流データをシミュレーションし、ステントデザイン適正性の検討を行った。

  12. 定量的血栓測定によるステント血栓化予測に有効な血行力学パラメータの抽出

    安西 眸

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Research Activity Start-up

    研究種目:Grant-in-Aid for Research Activity Start-up

    研究機関:Tohoku University

    2014年8月29日 ~ 2016年3月31日

    詳細を見る 詳細を閉じる

    本研究では,血栓生成と血流数値解析の比較から医療機器が介在する脳動脈瘤における血栓生成の定量的な知見を確立することを目的とする.脳動脈瘤近傍における低レイノルズ数環境下を再現するin vitro血液環流システムを構築し,ヤギ血を環流することで,生体外で血栓の生成を試みた.また,生体内では内皮細胞が血栓の生成を抑制することが知られている.フローチャンバー内で血流流れを付加した際に,内皮細胞が金属デバイス表面をどのように覆っていくか,細胞実験から明らかにした.

  13. 科学研究費助成事業 競争的資金

    安西 眸

    2014年4月 ~ 2016年3月

  14. 脳動脈瘤治療用ステントの形状最適化法の開発

    安西 眸

    2011年 ~ 2013年

    詳細を見る 詳細を閉じる

    当該年度はこれまでに開発を行ってきたステント形状最適化プログラムを実形状動脈瘤に対して適用し, 瘤内平均流速を目的関数とした際の最適ステント形状の算出を行った. 実形状動脈瘤では, 親血管の曲がり・捻じれによって発生する局所的な動脈瘤への流入(Bundle of Inflow, BOI)が観察されており, 最適ステント形状は, このBOI部にストラットが集中する形状となった. ステントの多孔率(ストラットの本数)を変化させ最適化を行い, 先行研究として行ってきた3次元可視化による最適ストラット位置の推定と比較を行ったところ, どちらのストラットもBOI内部に分布し, さらにはそのストラットによる瘤内の血流低減率も良い一致を示した. 最適化プログラムでは, 形状探索のために200形状を用いて数値解析を行っているが, 3次元可視化を用いた方法では2通りの数値解析のみで効果的なストラット位置を探索でき, したがって, これら2つの手法を組み合わせることで, 最適ステントを求めるために要する時間を劇的に短縮することが可能であると示唆される. 近年では動脈瘤治療や破裂予測のため, 動脈瘤形状を分類し, データベース化する研究が行われている. そこで, 瘤形状の分類に従い, ステント形状も分類し対応付けることで, 新しい医療デバイス設計に関する知見が得られる可能性が示唆された. 当該年度は, 本研究に関する研究で2本の雑誌投稿論文が採択されており, また翌年度にはステントの多孔率と最適化前後の血流低減率に関する論文を投稿予定である.

︎全件表示 ︎最初の5件までを表示

メディア報道 5

  1. COVID-19陽性者搬送車内の気流を可視化 ~ドライバーをウイルスから守る~

    khb東日本放送 チャージ!

    2022年2月15日

    メディア報道種別: テレビ・ラジオ番組

  2. COVID-19陽性者搬送車内の気流を可視化 ~ドライバーをウイルスから守る~

    仙台放送 Live news イット!

    2022年2月9日

    メディア報道種別: テレビ・ラジオ番組

  3. 飛沫の伝わり方予測、東北大が開発 せき直前の喉の動きをAI解析

    河北新報 ONLINE NEWS

    2021年11月19日

    メディア報道種別: インターネットメディア

  4. せきを画像から予測 東北大、瞬時の感染防御に

    日本経済新聞

    2021年11月12日

    メディア報道種別: インターネットメディア

  5. 冠動脈の流れ瞬時に予測

    日経産業新聞 日経産業新聞

    2021年3月8日

    メディア報道種別: 新聞・雑誌

学術貢献活動 1

  1. JOURNAL OF FLUID SCIENCE AND TECHNOLOGY 編集委員

    学術貢献活動種別: 査読等

その他 2

  1. ex vivo measurement and numarical analysis of heat propagation during steam ablation

    詳細を見る 詳細を閉じる

    As a new targeted, focal treatment of prostate cancer, we evaluate the potential use of steam ablation. To avoid undesirable side-effect, it is important to ablate only cancerous tissue. In this project, computational simulation is used to evaluate thermal propagation around medical devices and to optimize the methodology of steam ablation.

  2. 1. 差圧方式高速応答微少流量計の流路最適化研究

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    申請者が独自に開発した最適化プログラムに注目され、次世代高速チップマウンター用の高速応答微少流量計の開発に必要な基礎データの収集を行った。本成果は次世代流量計の開発方向性を決める一因として用いられた。