■Faculty | Department of Robotics / Graduate School of System Enginnering / Research Institute of Fundamental Technology for Next Generation |

■Position | Professor |

■Degree | Ph.D. in Engineering |

■Commentator Guide | https://www.kindai.ac.jp/meikan/2149-shirai-atsushi.html |

■URL | http://db.tohoku.ac.jp/whois/e_detail/4549a5511af54bb6c2fc5141c27c7bf5.html |

Last Updated :2020/09/14

- - 1998 03 25 , Tohoku University, Graduate School, Division of Engineering
- - 1993 03 , Tohoku University, Faculty of Engineering

- Manufacturing technology (mechanical, electrical/electronic, chemical engineering), Fluid engineering, Biofluid Mechanics

- Numerical Analysis, Capillary, Neutrophil

- Influence on measurement signal by pressure and viscosity changes of fluid and installation condition of FBG sensor using blood flow simulation model, Shouhei Koyama, Toshiyuki Hayase, Suguru Miyauchi, Atsushi Shirai, Shun Chino, Yuki Haseda, Hiroaki Ishizawa, IEEE Sensors Journal, IEEE Sensors Journal, PP(99)(1-1), Aug. 2019 , Refereed
- Differentiation of neutrophil-like HL-60 cells strongly impacts their rolling on surfaces with various adhesive properties under a pressing force, Atsushi Shirai, Yoshiro Sugiyama, Jean-Paul Rieu, Technology and Health care, Technology and Health care, 26(1), 93 - 108, 2018 , Refereed
- Universality of periodic oscillation induced in side branch of a T-junction in numerical simulation, Ryuhei Yamaguchi, Gaku Tanaka, Tadashi Nakagawa, Atsushi Shirai, Hao Liu, Toshiyuki Hayase, Journal of Flow Control, Measurement & Visualization, Journal of Flow Control, Measurement & Visualization, 5(4), 73 - 85, Oct. 2017 , Refereed
- Numerical analysis for elucidation of mechanical interaction between an erythrocyte moving in medium subject to inclined centrifugal force and endothelial cells on a plate, Akira Yatsuyanagi, Toshiyuki Hayase, Suguru Miyauchi, Kenichi Funamoto, Kosuke Inoue, Atsushi Shirai, Luca Brandt, Journal of Fluid Science and Technology, Journal of Fluid Science and Technology, 11(4), JFST0029, Dec. 2016 , Refereed
- Fundamental study on generation of a 3-D alveolar capillary network model based on the bubble mesh method, K. Yamada, A. Shirai, Proceedings of the 16th international conference on biomedical engineering, Proceedings of the 16th international conference on biomedical engineering, Dec. 2016
- Influence of pressing force on rolling characteristics of HL-60 cell line on a bumpy substrate mimicking the endothelium topography, A. Shirai, J.-P. Rieu, R. Sugimoto, D. Yoshino, Prceedings of The 16th International Conference on Biomedical Engineering, Prceedings of The 16th International Conference on Biomedical Engineering, Dec. 2016
- Hemodynamic model of acupuncture therapy, A. Shirai, Medical Engineering and Preclinical Studies, Medical Engineering and Preclinical Studies, 2, 21 - 22, Nov. 09 2016
- Correlative effect of normal force and P-selectin concentration on rolling behavior of neutrophils, R. Sugimoto, A. Shirai, D. Yoshino, J.-P. Rieu, Proc. 13th International Conference on Flow Dynamics, Proc. 13th International Conference on Flow Dynamics, 704 - 705, Oct. 2016
- Development of 2-D pulmonary capillary network model based on the bubble mesh method: Effects of segmentation and treatment of border capillaries on capillary length, h International Conference on Flow, Dynamics (IC, Proceeding of 13th international conference on flow dynamics, Proceeding of 13th international conference on flow dynamics, 278 - 279, Oct. 2016
- Rolling characteristics of neutrophils on PDMS surface mimicking the endothelial topography: PTV analysis of the cells motion on regular hexagonal pattern, A. Shirai, J.-P. Rieu, R. Sugimoto, D. Yoshino, Proceedings of 13th International Conference on Flow Dynamics, Proceedings of 13th International Conference on Flow Dynamics, 286 - 287, Oct. 2016
- Numerical reproduction of hemodynamics change by acupuncture on Taichong (LR-3) based on the lumped-parameter approximation model of the systemic arteries, Atsushi Shirai, Takuya Suzuki, Takashi, Seki, Integrative Medicine Research, Integrative Medicine Research, 4(3), 161 - 170, Sep. 2016 , Refereed
- 水棲微小生物の繊毛遊泳脚による推進機構に関する数値解析(単一遊泳脚モデルの繊毛間隔が推進力に与える影響), A. Shirai, K. Inoue, T. Hayase, S. Sudo, 日本機械学会論文集, 日本機械学会論文集, 82(840), Aug. 2016 , Refereed
- On the Motility and Locomotive Organs of Beach Flea, Seiichi Sudo, Takuya Amano, Atsushi Shirai, Toshiyuki Hayase, Journal of Aero Aqua Bio-mechanisms, Journal of Aero Aqua Bio-mechanisms, 4(1), 37 - 43, Aug. 2015 , Refereed
- Rolling characteristics of neutrophils on PDMS surface mimicking the endothelium topography, Jean-Paul Rieu, Atsushi Shirai, 2015 Annual ELyT Workshop Abstract Book, 2015 Annual ELyT Workshop Abstract Book, Feb. 2015
- On the Motility and Locomotive Organs of Beach Flea, Seiichi Sudo, Atsushi Shirai, Toshiyuki Hayase, Takuya Amano, Proceedings of ISABME2014, Proceedings of ISABME2014, Nov. 2014
- Fundamental characteristics of motion of neutrophil-lik HL-60 cells on glass plate, Atsushi Shirai, Yoshiro, Sugiyama, 2014 Annual ELyT Workshop Abstract Book, 2014 Annual ELyT Workshop Abstract Book, Feb. 2014
- Influence of differentiation of HL-60 cells on their motion on a flat glass plate, Yoshiro Sugiyama, Atsushi Shirai, Programme & Abstracts ICBME2013, Programme & Abstracts ICBME2013, Dec. 2013
- The Kinematics of Jumping of Globular Springtail, Seiichi Sudo, Masahiro Shiono, Toshiya Kainuma, Atsushi Shirai, Toshiyuki Hayase, Journal of Aero Aqua Bio-mechanisms, Journal of Aero Aqua Bio-mechanisms, 3(1), 85 - 91, May 2013 , Refereed
- Observations on the Springtail Leaping Organ and Jumping Mechanism Worked by a Spring, Seiichi Sudo, Masahiro Shiono, Toshiya Kainuma, Atsushi Shirai, Toshiyuki Hayase, Journal of Aero Aqua Bio-mechanisms, Journal of Aero Aqua Bio-mechanisms, 3(1), 92 - 96, May 2013 , Refereed
- 植物表面細胞の形状計測－植物流体力学的アプローチ－, 須藤誠一, 塩野正裕, 白井敦, 早瀬敏幸, 実験力学, 実験力学, 12(4), 338 - 343, Dec. 2012 , Refereed
- The Jump of the Globular Springtail and Jumping Mechanism Worked by a Spring, S. Sudo, M. Shiono, A. Shirai, T. Hayase, Proceedings of the 5th International Symposium on Aero Aqua Bio-mechanisms, Proceedings of the 5th International Symposium on Aero Aqua Bio-mechanisms, Aug. 2012
- Influence of Pressing Force on Motion of HL60 Cells on HUVEC substrate, A. Shirai, H. Uranuma, T. Hayase, Journal of Biomechanics, Journal of Biomechanics, 45(1), S41, Jul. 2012
- Dynamics in Motion of Dandelion Flower Head, S. Sudo, M. Shiono, A. Shirai, T. Hayase, Proceedings of 15th International Conference on Experimental Mechanics (ICEM15), Proceedings of 15th International Conference on Experimental Mechanics (ICEM15), 483 - 484, Jul. 2012 , Refereed
- Motion of fMLP-Stimulated HL60 Cells on HUVEC Cultured on a Flat Glass Plate, A. Shirai, H. Sato, T. Hayase, Proceedings of Surface Modification Technologies XXVI, Proceedings of Surface Modification Technologies XXVI, Jun. 2012 , Refereed
- Behavior of HL60 cells on HUVEC substrate under inclined centrifugal forces, A. Shirai, H. Uranuma, T. Hayase, 2012 Annual ELyT Workshop Abstract Book, 2012 Annual ELyT Workshop Abstract Book, Mar. 2012
- 微小な海浜生物のいくつかの移動様式, 須藤誠一, 星加恭平, 白井敦, 早瀬敏幸, 実験力学, 実験力学, 11(2), 91 - 100, Jun. 2011 , Refereed
- An Alligning Technique of Successive Images Taken by the Inclined Centrifuge Microscope, Atsushi Shirai, P2010 Annual ELyT Workshop Abstract Book, P2010 Annual ELyT Workshop Abstract Book, Mar. 2010
- Experimental Observation of Behavior of Neutrophil-like HL60 Cells on Oriented Endothelial Cells, Haruka Uranuma, Atsushi Shirai, Toshiyuki Hayase, Proceedings of 3rd East Asian Pacific Student Workshop on Nano-Biomedical Engineering, Proceedings of 3rd East Asian Pacific Student Workshop on Nano-Biomedical Engineering, 22 - 23, Dec. 2009
- Numerical simulation of distribution of neutrophils in a lattice alveolar capillary network, Atsushi Shirai, Toshiyuki Hayase, Respiratory Physiology & Neurobiology, Respiratory Physiology & Neurobiology, 10.1016/j.resp.2008.11.00, 1 - 11, Dec. 2008 , Refereed
- Measurement of Friction Characteristics of Neutrophils on MPC Polymer with the Inclined Centrifuge Microscope, Takashi Umimoto, Atsushi Shirai, Toshiyuki Hayase, Proceedings of GPBE/NUS-Tohoku Graduate Student Conference in Bioengineering, Proceedings of GPBE/NUS-Tohoku Graduate Student Conference in Bioengineering, 11 - 12, Dec. 2008
- Reproduction of Pulse Waveform Measurement using One-dimensional Mathematical Model for Validation of Pulse Diagnosis, Tsutomu Nakanishi, Atsushi Shirai, Toshiyuki Hayase, Proceedings of GPBE/NUS-Tohoku Graduate Student Conference in Bioengineering, Proceedings of GPBE/NUS-Tohoku Graduate Student Conference in Bioengineering, 9 - 10, Dec. 2008
- Development of one-dimensional mathematical model for validation of pulse diagnosis, Kentaro NARUMI, Tsutomu NAKANISHI, Atsushi SHIRAI, Toshiyuki HAYASE, 日本機械学会論文集(B編), 日本機械学会論文集(B編), 74(737), 142 - 148, Jan. 2008 , Refereed
- EFFECT OF RETENTION TIME OF NEUTROPHILS IN ALVEOLAR CAPILLARIES ON INCREASE IN THEIR CONCENTRATION IN THE CAPILLARY NETWORK, Atsushi SHIRAI, Toshiyuki HAYASE, Proceedings of the 5th Joint ASME/JSME Fluids Engineering Conference, Proceedings of the 5th Joint ASME/JSME Fluids Engineering Conference, FEDSM2007 - 37653, Oct. 2007 , Refereed
- EFFECT OF NEUTROPHILS RETENTION TIME IN CAPILLARIES ON INCREASE IN THEIR CONCENTRATION IN A LATTICE CAPILLARY NETWORK MODEL, Atsushi SHIRAI, Toshiyuki HAYASE, Proceedings of the ASME 2007 Summer Bioengineering Conference, Proceedings of the ASME 2007 Summer Bioengineering Conference, SBC2007 - 176717, Jun. 2007
- Numerical simulation of 3-D deformation of a neutrophil in a rectangular microchannel, Atsushi SHIRAI, Sunao MASUDA, Toshiyuki HAYASE, Journal of Biomechanics (Abstract of the 5th World Congress of Biomechanics), Journal of Biomechanics (Abstract of the 5th World Congress of Biomechanics), 333 - CD-ROM, Aug. 2006
- 3-D NUMERICAL SIMULATION OF FLOW OF A NEUTROPHIL FOR THE RETENTION TIME IN A MODERATE CONSTRICTION OF A RECTANGULAR MICROCHANNEL, Atsushi Shirai, Sunao Masuda, Toshiyuki Hayase, Proceedings of BIO2006 (ASME 2006 Summer Bioengineering Conference), Proceedings of BIO2006 (ASME 2006 Summer Bioengineering Conference), CD-ROM, Jun. 2006
- Numerical Simulation of Flow and Deformation of a Neutrophil Passing Through a Constriction in a Fine Capillary, Atsushi SHIRAI, Ryo FUJITA, Toshiyuki HAYASE, Reports of the Institute of Fluid Science, Tohoku University, Reports of the Institute of Fluid Science, Tohoku University, 18, 2006 Summary:Published in the Proc. 5th JSME-KSME Fluid Eng. Conf., (2002).
- Moderate Constriction Model for Neutrophils Flow in Pulmonary Capillaries, A. Shirai, R. Fujita, T. Hayase, Proceedings of the 7th International Symposium of Future Medical Engineering Based on Bio-nanotechnology, Proceedings of the 7th International Symposium of Future Medical Engineering Based on Bio-nanotechnology, 8 - 11, Dec. 2005 Summary:Held as Symposia of Future Medical Engineering Based on Bio-nanotechnology in the 12 th International Conference on Biomedical Engineering (ICBME2005), Singapore
- Numerical Analysis of Effect of Cross-section of Microchannel on Transit Characteristics of a Neutrophil, Sunao MASUDA, Atsushi SHIRAI, Toshiyuki HAYASE, Proceedings of the Fifth International Symposium on Advanced Fluid Information, Proceedings of the Fifth International Symposium on Advanced Fluid Information, 64 - 65, Dec. 2005
- Numerical Simulation for Spatial Distribution of Neutrophils in Capillary Network, Atsushi Shirai, Toshiyuki Hayase, Proc. the 6th International Symposium on Future Medical Engineering based on Bio-nanotechnology (21st Century COE Program), Proc. the 6th International Symposium on Future Medical Engineering based on Bio-nanotechnology (21st Century COE Program), 60 - 61, Nov. 2005
- Three-Dimensional Numerical Analysis Of Plasma Flow Around A Neutrophil In A Microchannel, Atsushi Shirai, Sunao Masuda, Toshiyuki Hayase, Proceedings of the ASME 2005 Summer Bioengineering Conference, Proceedings of the ASME 2005 Summer Bioengineering Conference, CD-ROM, Jun. 2005 , Refereed
- Inclined Centrifuge Microscope For Measuring Frictional Characteristics Of Red Blood Cells Moving On Glass Plate In Plasma, Toshiyuki Hayase, Hidekatsu sugiyama, Takayuki Yamagata, Kosuke Inoue, Atsushi Shirai, Motohiro Takeda, Proceedings of the ASME 2005 Summer Bioengineering Conference, Proceedings of the ASME 2005 Summer Bioengineering Conference, CD-ROM, Jun. 2005 , Refereed
- FLOW SIMULATION OF NEUTROPHILS IN CAPILLARY NETWORK (EFFECT OF CAPILLARY GEOMETRY ON TRANSIT TIME OF CELLS THROUGH NETWORK), Atsushi Shirai, Ryo Fujita, Toshiyuki Hayase, Proceedings of the Third IASTED International Conference on Biomedical Engineering (BioMED 2005), Proceedings of the Third IASTED International Conference on Biomedical Engineering (BioMED 2005), 284 - 289, Feb. 2005 , Refereed
- Effect of Cell Stiffness on Transit Through Pulmonary Capillary Network, Atsushi Shirai, Ryo Fujita, Toshiyuki Hayase, Proceedings of The Fourth International Symposium on Advanced Fluid Information and The First International Symposium on Transdisciplinary Fluid Integration, Proceedings of The Fourth International Symposium on Advanced Fluid Information and The First International Symposium on Transdisciplinary Fluid Integration, 26 - 27, Nov. 2004
- Flow Simulation of Neutrophils in Pulmonary Capillary Network, Atsushi Shirai, Ryo Fujita, Toshiyuki Hayase, Proceedings of the 4th International Symposium on Future Medical Engineering based on Bio-nanotechnology (21st Century COE Program), Proceedings of the 4th International Symposium on Future Medical Engineering based on Bio-nanotechnology (21st Century COE Program), 28 - 29, Jun. 2004
- Application of Ultrasonic-Measuremenet-Integrated Simulation to Blood Flow, Kenichi Funamoto, Toshiyuki Hayase, Atsushi Shirai, Yoshifumi Saijo, Tomoyuki Yambe, Proceedings of the 4th International Symposium on Future Medical Engineering based on Bio-nanotechnology (21st Century COE Program), Proceedings of the 4th International Symposium on Future Medical Engineering based on Bio-nanotechnology (21st Century COE Program), 78 - 79, Jun. 2004
- Microscopic Observation of Red Blood Cells Moving on Glass Plate under Inclined Centrifugal Force, Kotomi Saito, Takayuki Yamagata, Toshiyuki Hayase, Atsushi Shirai, Kosuke Inoue, Motohiro takeda, Proceedings of the 4th International Symposium on Future Medical Engineering based on Bio-nanotechnology (21st Century COE Program), Proceedings of the 4th International Symposium on Future Medical Engineering based on Bio-nanotechnology (21st Century COE Program), 86 - 87, Jun. 2004
- Development of a Measurement System of Blood Cell Velocities in Microchannels, Sunao Masuda, Atsushi Shirai, Toshiyuki Hayase, Proceedings of the 4th International Symposium on Future Medical Engineering based on Bio-nanotechnology (21st Century COE Program), Proceedings of the 4th International Symposium on Future Medical Engineering based on Bio-nanotechnology (21st Century COE Program), 88 - 89, Jun. 2004
- TRANSIT CHARACTERISTICS OF A DEFORMED NEUTROPHIL THROUGH A MODERATE CONSTRICTION, Atsushi Shirai, Ryo Fujita, Toshiyuki Hayase, Proceedings of 2003 ASME International Mechanical Engineering Congress, Proceedings of 2003 ASME International Mechanical Engineering Congress, Nov. 2003 Summary:CD-ROM

IMECE2003-55020 - Reproduction of Real Blood Flow in Aorta with Ultrasonic-Measurement-Integrated Simulation, kenichi Funamoto, Toshiyuki Hayase, Atsushi Shirai, Tomoyuki Yambe, Yoshifumi Saijo, Proceedings of Third International Symposium on Advanced Fluid Information (AFI-2003), Proceedings of Third International Symposium on Advanced Fluid Information (AFI-2003), 39 - 40, Nov. 2003
- Numerical Analysis for Affect of Neutrophil Shape on Transit Through Capillaries, Atsushi Shirai, Ryo Fujita, Toshiyuki Hayase, Proceedings of Third International Symposium on Advanced Fluid Information (AFI-2003), Proceedings of Third International Symposium on Advanced Fluid Information (AFI-2003), 41 - 42, Nov. 2003
- PARTIALLY PRESSURIZED COLLAPSIBLE TUBE MODEL, Satoru Hayashi, Masaru Maruyama, Toshiyuki Hayase, Atsushi Shirai, Proceedings of 7th Triennial International Symposium on Fluid Control, Measurement and Visualization (FLUCOME '03), Proceedings of 7th Triennial International Symposium on Fluid Control, Measurement and Visualization (FLUCOME '03), Aug. 2003 Summary:CD-ROM
- Measurement of Frictional Characteristics of Red Blood Cells Moving on a Plate in Plasma due to Inclined Centrifugal Force, 早瀬敏幸, 白井敦, 杉山英勝, 濱谷剛, 日本機械学会論文集(Ｂ編), 日本機械学会論文集(Ｂ編), 68(676), 158 - 163, Dec. 2002 , Refereed
- Analysis of Dynamic Characteristics of Water Hydraulic Relief Valve, 林叡, 中西貴之, 早瀬敏幸, 白井敦, 日本フルードパワーシステム学会論文集, 日本フルードパワーシステム学会論文集, 33(7), 149 - 155, Nov. 2002 , Refereed
- FLOW AND DEFORMATION OF A NEUTROPHIL PASSING THROUGH A CONSTRICTION IN A FINE CAPILLARY, Atsushi Shirai, Ryo Fujita, Toshiyuki Hayase, Proceedings of The Fifth JSME-KSME Fluids Engineering Conference, Proceedings of The Fifth JSME-KSME Fluids Engineering Conference, 82, Nov. 2002 , RefereedSummary:Proceedings + CD-ROM
- FUNDAMENTAL CONSIDERATION ON NUMERICAL ANALYSIS OF UNSTEADY FLOW THROUGH SPOOL VALVE, Toshiyuki Hayase, Yupeng Xia, Atsushi Shirai, Satoru Hayashi, Proceedings of the Fifth JFPS International Symposium, Proceedings of the Fifth JFPS International Symposium, 3, 929 - 934, Nov. 2002 , Refereed
- EFFECT OF CONSTRICTION GEOMETRY ON TRANSIT OF DEFORMABLE NEUTROPHILS IN CAPILLARIES, Atsushi Shirai, Ryo Fujita, Toshiyuki Hayase, Proceedings of IV World Congress of Biomechanics (WCB2002), Proceedings of IV World Congress of Biomechanics (WCB2002), Aug. 2002 Summary:CD-ROM
- Numerical Realization of Flow Field by Integrating Computation and Measurement, Toshiyuki Hayase, Keusuke Nisugi, Atsushi Shirai, Proceedings of the Fifth World Congress on Computational Mechanics (WCCM V), Proceedings of the Fifth World Congress on Computational Mechanics (WCCM V), Jul. 2002 , RefereedSummary:Paper ID: 81524

http://wccm.tuwien.ac.at/ - Multi-Scale Simulation in Biological System, Roger D. Kamm, Eun-Bo Shim, Atsushi Shirai, Mark Bathe, Thomas Heldt, Hesham Younis, Ana Isasi, Mohammad Kaazempur-Mofrad, Wonmuk Hawang, Proceedings of the First International Symposium on Advanced Fluid Information (AFI-2001), Proceedings of the First International Symposium on Advanced Fluid Information (AFI-2001), 121 - 124, Oct. 2001
- The Effect of Neutrophil Activation on Transit Time through Pulmonary Capillaries, Atsushi Shirai, Mark Bathe, Toshiyuki Hayase, Proceedings of the First International Symposium on Advanced Fluid Information (AFI-2001), Proceedings of the First International Symposium on Advanced Fluid Information (AFI-2001), 125 - 130, Oct. 2001
- Numerical Realization of Flow by Integrating Computation and Measurement in Medical Applications, Toshiyuki Hayase, Kenichi Funamoto, Keisuke Nisugi, Atsushi Shirai, Tomoyuki Yambe, Yoshifumi Saijo, Proceedings of the First International Symposium on Advanced Fluid Information (AFI-2001), Proceedings of the First International Symposium on Advanced Fluid Information (AFI-2001), 77 - 85, Oct. 2001
- Influence of Pipeline Friction on Chaotic Oscillations in a Direct-Acting Poppet Valve Circuit, 林叡, 王偉民, 早瀬敏幸, 白井敦, 日本油空圧学会論文集, 日本油空圧学会論文集, 31(5), 123 - 131, Aug. 2000 , Refereed
- AERODYNAMIC DRAG REDUCTION BY FEEDBACK CONTROL OF FLOW FIELD, Keisuke Nisugi, Toshiyuki Hayase, Atsushi Shirai, Proceedings of the 6th Triennial International Symposium on Fluid Control, Measurement and Visualization (FLUCOME 2000), Proceedings of the 6th Triennial International Symposium on Fluid Control, Measurement and Visualization (FLUCOME 2000), Aug. 2000 Summary:CD-ROM
- Numerical Analysis of Flow Around the Main Valve of Hydraulic Damper and Effect of Axial Flow Force on Stability of the Damper, 佐藤直人, 林叡, 早瀬敏幸, 白井敦, 日本油空圧学会論文集, 日本油空圧学会論文集, 31(1), 22 - 29, Jan. 2000 , Refereed
- EIGENVALUE ANALYSIS OF DIRECT ACTING POPPET VALVE CIRCUIT, Atsushi Shirai, Satoru Hayashi, Toshiyuki Hayase, Weimin Wang, Fluid Power (Proceedings of the Fourth JHPS International Symposium), Fluid Power (Proceedings of the Fourth JHPS International Symposium), 303 - 308, Nov. 1999 , Refereed
- NUMERICAL SIMULATION OF WATER HYDRAULIC RELIEF VALVE, Takayuki Nakanishi, Satoru Hayashi, Toshiyuki Hayase, Atsushi Shirai, Masao Jotatsu, Hideki Kawamoto, Fluid Power (Proceedings of the Fourth JHPS International Symposium), Fluid Power (Proceedings of the Fourth JHPS International Symposium), 555 - 560, Nov. 1999 , Refereed
- CHAOTIC OSCILLATIONS IN A DIRECT-ACTING POPPET VALVE CIRCUIT (PIPELINE LENGTH AS A CONTROL PARAMETER), Weimin Wang, Satoru Hayashi, Toshiyuki Hayase, Atsushi Shirai, Fluid Power (Proceedings of the Fourth JHPS International Symposium), Fluid Power (Proceedings of the Fourth JHPS International Symposium), 597 - 602, Nov. 1999 , Refereed
- Chaotic Oscillations in a Direct-Acting Poppet Valve Circuit (Case of a Long Pipeline), 王偉民, 林叡, 早瀬敏幸, 白井敦, Transactions of the Japan Hydranlics & Pneumatics Society, Transactions of the Japan Hydranlics & Pneumatics Society, 30(5), 119 - 127, Aug. 1999 , Refereed
- Eigenvalue Analysis of Direct-Acting Poppet Valve Circuit, 白井敦, 林叡, 早瀬敏幸, 王偉民, Transactions of the Japan Hydranlics & Pneumatics Society, Transactions of the Japan Hydranlics & Pneumatics Society, 30(3), 75 - 80, May 1999 , Refereed
- Local Stability of a Direct-Acting Poppet Valve Circuit with a Long Pipeline, Weimin Wang, Satoru Hayashi, Toshiyuki Hayase, Atsushi Shirai, 日本油空圧学会論文集, 日本油空圧学会論文集, 30(3), 67 - 74, May 1999 , Refereed
- DEFORMATION OF RED BLOOD CELLS IN FINE CAPILLARIES, Atsushi Shirai, Satoru Hayashi, Toshiyuki Hayase, Satoyuki Kawano, Proceedings of the International Conference on New Frontiers in Biomechanical Engineering, Proceedings of the International Conference on New Frontiers in Biomechanical Engineering, 399 - 402, Jul. 1997
- Numerical Analysis of Flow Pattern and Mass Transfer Around an Axisymmetric Red Blood Cell Moving in a Fine Capillary, 白井敦, 川野聡恭, 橋本弘之, 仁田新一, 医用電子と生体工学, 医用電子と生体工学, 34(2), 151 - 160, Jun. 1996 , Refereed
- Computer Aided flow Visualization and Animation on Three-Dimensional Solid-Liquid Two-Phase Jet at Low Reynolds Numbers, Hiroyuki Hashimoto, Satoyuki Kawano, Atsushi Shirai, Akio Ihara, Tatsuya Yamamoto, Proceedings of The 2nd International Conference on Multiphase Flow '95-Kyoto, Proceedings of The 2nd International Conference on Multiphase Flow '95-Kyoto, 4, AV-9 - AV-16, Apr. 1995 , Refereed
- APPLICABILITY OF LUBRICATION THEORY TO BLOOD CELLS MOTION IN FINE CAPILLARIES, Hiroyuki Hashimoto, Satoyuki Kawano, Atsushi Shirai, Akio Ihara, Proceedings of the Third JSME-KSME Fluids Engineering Conference, Proceedings of the Third JSME-KSME Fluids Engineering Conference, 166 - 170, Jul. 1994
- Photoplethysmography and ultrasonic-measurement-integrated simulation to clarify the relation between two-dimensional unsteady blood flow field and forward and backward waves in a carotid artery, Shusaku Sone, Toshiyuki Hayase, Kenichi Funamoto, Atsushi Shirai, MEDICAL & BIOLOGICAL ENGINEERING & COMPUTING, MEDICAL & BIOLOGICAL ENGINEERING & COMPUTING, 55(5), 719 - 731, May 2017 , RefereedSummary:Understanding the spatiotemporal change in hemodynamics is essential for the basic research of atherosclerosis. The objective of this study was to establish a methodology to clarify the relation between a two-dimensional (2D) unsteady blood flow field and forward and backward propagating waves in a carotid artery. This study utilized photoplethysmography (PPG) for blood pressure measurement and two-dimensional ultrasonic-measurement-integrated (2D-UMI) simulation for flow field analysis. The validity of the methodology was confirmed in an experiment for a carotid artery of a healthy volunteer. Synchronization between the pressure measurement and flow field analysis was achieved with an error of < 10 ms. A 2D unsteady blood flow field in the carotid artery was characterized in relation to forward and backward waves. 2D-UMI simulation reproduced the flow field in which the wall shear stress takes a maximum at the time of the backward wave superiority in the systolic phase, whereas 2D ordinary simulation failed to reproduce this feature because of poor reproducibility of velocity distribution. In conclusion, the proposed methodology using PPG and 2D-UMI simulation was shown to be a potential tool to clarify the relation between 2D unsteady blood flow field and the forward and backward waves in a carotid artery.
- Photoplethysmography and ultrasonic-measurement-integrated simulation to clarify the relation between two-dimensional unsteady blood flow field and forward and backward waves in a carotid artery, Shusaku Sone, Toshiyuki Hayase, Kenichi Funamoto, Atsushi Shirai, MEDICAL & BIOLOGICAL ENGINEERING & COMPUTING, MEDICAL & BIOLOGICAL ENGINEERING & COMPUTING, 55(5), 719 - 731, May 2017 , RefereedSummary:Understanding the spatiotemporal change in hemodynamics is essential for the basic research of atherosclerosis. The objective of this study was to establish a methodology to clarify the relation between a two-dimensional (2D) unsteady blood flow field and forward and backward propagating waves in a carotid artery. This study utilized photoplethysmography (PPG) for blood pressure measurement and two-dimensional ultrasonic-measurement-integrated (2D-UMI) simulation for flow field analysis. The validity of the methodology was confirmed in an experiment for a carotid artery of a healthy volunteer. Synchronization between the pressure measurement and flow field analysis was achieved with an error of < 10 ms. A 2D unsteady blood flow field in the carotid artery was characterized in relation to forward and backward waves. 2D-UMI simulation reproduced the flow field in which the wall shear stress takes a maximum at the time of the backward wave superiority in the systolic phase, whereas 2D ordinary simulation failed to reproduce this feature because of poor reproducibility of velocity distribution. In conclusion, the proposed methodology using PPG and 2D-UMI simulation was shown to be a potential tool to clarify the relation between 2D unsteady blood flow field and the forward and backward waves in a carotid artery.
- Systematical Experiment for Optimal Design of Vibrating Flow Pump with Jelly-fish Valve, Satoyuki Kawano, Saki Miyagawa, Atsushi Shirai, JOURNAL OF BIONIC ENGINEERING, JOURNAL OF BIONIC ENGINEERING, 13(1), 166 - 179, Jan. 2016 , RefereedSummary:The fundamental characteristics and the flow mechanism of a Vibrating Flow Pump (VFP) with a jelly-fish valve, which can be applied to a novel artificial heart, were studied theoretically and experimentally. By using water as the working fluid, the measurement methodology for the typical unsteady flow for VFP was developed here. The effects of the frequency, amplitude and inner diameter of the vibrating pipe, and thickness of the silicone rubber sheet of the jelly-fish valve on the basic performance of VFP were systematically investigated. A high-speed observation technique and simple theoretical model analysis were also introduced for further detailed discussion. Quantitative contributions of the individual parameters to the pumping performance were shown through the experiment, which would give us essential knowledge for establishing design criteria of VFP. The theoretical model, which agreed with the experiment and the high-speed observation, elucidated the pumping mechanism with respect to the role of inertia of the inner fluid.
- A numerical study on the performance of micro-vibrating flow pumps using the immersed boundary method, Osman Omran Osman, Atsushi Shirai, Satoyuki Kawano, MICROFLUIDICS AND NANOFLUIDICS, MICROFLUIDICS AND NANOFLUIDICS, 19(3), 595 - 608, Sep. 2015 , RefereedSummary:A micro-vibrating flow pump (micro-VFP) drives the fluid by the vibration of an elastic cantilever-like structure in the pump, which is actuated by a sinusoidal magnetic field. In the present study, we clarify the pumping mechanism of the micro-VFP through a numerical simulation. A two-dimensional simulation code based on the immersed boundary method was developed to obtain the flow field in the micro-VFP together with the vibration of the cantilever. The motion of the cantilever, which was imitated by the immersed body, was expressed as an external forcing term of the Navier-Stokes equations. Here, the magnetic force required to actuate the cantilever was calculated based on a two-dimensional magnetic model, and an integral approach was used to calculate the large deflection of the cantilever. The working conditions and length of the cantilever were numerically studied to determine their effects on the pumping performance. It was shown through the numerical simulations that the pumping mechanism could be explained as a result of elongation of the cantilever in the effective stroke induced by the actuating magnetic field. The pumping performance, which was characterized by the volumetric flow rate and the shut-off pressure, was enhanced by increasing the actuation frequency of the cantilever as has been found in previous experiments. It was also found that the cantilever has an optimum length to give the maximum flow rate. The mechanism was explained with respect to the kinetic energy transferred to the fluid by the vibrating cantilever and the choking level, which is determined by the clearance between the ceiling of the microchannel and the tip of the cantilever.
- Numerical Analysis for Elucidation of Nonlinear Frictional Characteristics of a Deformed Erythrocyte Moving on a Plate in Medium Subject to Inclined Centrifugal Force, Takashi Oshibe, Toshiyuki Hayase, Kenichi Funamoto, Atsushi Shirai, JOURNAL OF BIOMECHANICAL ENGINEERING-TRANSACTIONS OF THE ASME, JOURNAL OF BIOMECHANICAL ENGINEERING-TRANSACTIONS OF THE ASME, 136(12), 121003, Dec. 2014 , RefereedSummary:Complex interactions between blood cells, plasma proteins, and glycocalyx in the endothelial surface layer are crucial in microcirculation. To obtain measurement data of such interactions, we have previously performed experiments using an inclined centrifuge microscope, which revealed that the nonlinear velocity-friction characteristics of erythrocytes moving on an endothelia-cultured glass plate in medium under inclined centrifugal force are much larger than those on plain or material-coated glass plates. The purpose of this study was to elucidate the nonlinear frictional characteristics of an erythrocyte on plain or material-coated glass plates as the basis to clarify the interaction between the erythrocyte and the endothelial cells. We propose a model in which steady motion of the cell is realized as an equilibrium state of the force and moment due to inclined centrifugal force and hydrodynamic flow force acting on the cell. Other electrochemical effects on the surfaces of the erythrocyte and the plate are ignored for the sake of simplicity. Numerical analysis was performed for a three-dimensional flow of a mixture of plasma and saline around a rigid erythrocyte model of an undeformed biconcave shape and a deformed shape with a concave top surface and a flat bottom surface. A variety of conditions for the concentration of plasma in a medium, the velocity of the cell, and the minimum gap width and the angle of attack of the cell from the plate, were examined to obtain the equilibrium states. A simple flat plate model based on the lubrication theory was also examined to elucidate the physical meaning of the model. The equilibrium angle of attack was obtained only for the deformed cell model and was represented as a power function of the minimum gap width. A simple flat plate model qualitatively explains the power function relation of the frictional characteristics, but it cannot explain the equilibrium relation, confirming the computational result that the deformation of the cell is necessary for the equilibrium. The frictional characteristics obtained from the present computation qualitatively agree with those of former experiments, showing the validity of the proposed model.
- Numerical Simulation of Passage of a Neutrophil through a Rectangular Channel with a Moderate Constriction, Atsushi Shirai, Sunao Masuda, PLOS ONE, PLOS ONE, 8(3), Mar. 2013 , RefereedSummary:The authors have previously presented a mathematical model to predict transit time of a neutrophil through an alveolar capillary segment which was modeled as an axisymmetric arc-shaped constriction settled in a cylindrical straight pipe to investigate the influence of entrance curvature of a capillary on passage of the cell. The axially asymmetric cross section of a capillary also influences the transit time because it requires three-dimensional deformation of a cell when it passes through the capillary and could lead to plasma leakage between the cell surface and the capillary wall. In this study, a rectangular channel was introduced, the side walls of which were moderately constricted, as a representative of axially asymmetric capillaries. Dependence of transit time of a neutrophil passing through the constriction on the constriction geometry, i.e., channel height, throat width and curvature radius of the constriction, was numerically investigated, the transit time being compared with that through the axisymmetric model. It was found that the transit time is dominated by the throat hydraulic diameter and curvature radius of the constriction and that the throat aspect ratio little affects the transit time with a certain limitation, indicating that if an appropriate curvature radius is chosen, such a rectangular channel model can be substituted for an axisymmetric capillary model having the same throat hydraulic diameter in terms of the transit time by choosing an appropriate curvature radius. Thus, microchannels fabricated by the photolithography technique, whose cross section is generally rectangular, are expected to be applicable to in vitro model experiments of neutrophil retention and passage in the alveolar capillaries.
- Numerical analysis of one-dimensional mathematical model of blood flow to reproduce fundamental pulse wave measurement for scientific verification of pulse diagnosis, Atsushi Shirai, Tsutomu Nakanishi, Toshiyuki Hayase, Journal of Biomechanical Science and Engineering, Journal of Biomechanical Science and Engineering, 6(4), 330 - 342, 2011 , RefereedSummary:Pulse diagnosis in traditional Chinese medicine is said to be able to detect not only illness but also decline of health in the patients from tactile sense of the pulse in the radial artery at the wrists. This diagnosis, however, is not supported by concrete scientific evidence. The authors have proposed a non-linear spring model of subcutaneous tissue on the radial artery and one-dimensional arterial blood flow model in an arm for the purpose of scientific verification of the pulse diagnosis. They performed, in the former study, a numerical experiment with this mathematical model in which the radial artery was indented in a stepwise manner by a pressure sensor, which extract the fundamental mechanism of the pulse diagnosis, to validate the subcutaneous tissue model and to find the appropriate coefficient to fit the experimental result. They investigated, in this research, contribution of parameters of supply pressure of the blood and tube law of the artery on the change in the pressure pulse waves with the indentation steps with respect to mean value P oav and amplitude ΔP o of the pressure. It was shown that mean supply pressure affects both P oav and ΔP o, while amplitude of the supply pressure affects ΔP o. It was also shown that profile of ΔP o vs. distance of the indentation changes drastically as the artery becomes hard. Lastly, it was examined to reproduce the experimentally obtained pressure pulse waves during the indentation in their former work with the mathematical model by adjusting the parameters. The result showed better agreement than the former result, but it implied that ulnar artery had to be taken into consideration for quantitative fitting of the pulse waves to the range where the radial artery was nearly flattened by the indentation. © 2011 by JSME.
- Numerical simulation of distribution of neutrophils in a lattice alveolar capillary network, Atsushi Shirai, Toshiyuki Hayase, RESPIRATORY PHYSIOLOGY & NEUROBIOLOGY, RESPIRATORY PHYSIOLOGY & NEUROBIOLOGY, 165(2-3), 143 - 153, Feb. 2009 , RefereedSummary:Neutrophils are known to be retained in narrow pulmonary capillaries, even in normal lungs, due to their low deformability, resulting in a higher concentration than that in systemic circulation. In this study, to obtain a fundamental understanding of the behavior of neutrophils, we simplified an alveolar capillary network to a rectangular grid of short capillary segments and numerically investigated the flow of a suspension of neutrophils and plasma through the capillary network for various concentrations of the suspension, C(sus), injected into the network. The cells traveled limited preferential paths in the network while C(sus) was low. Retention of a cell or cells induced plugging of the segment with a cessation of blood flow, and as the result of the changed plasma flow field caused by such plugging, the cells took various routes differing from the preferential paths. A low incidence of plugging helped to accelerate the cells flowing in the network with tight segments, resulting in a decrease in their mean transit time through the network as compared with the case of a single-cell transit. On the contrary, however, an increasing incidence of plugging induced backward motion of the cells and a resultant increase in the mean transit time. The time-averaged number of cells in the network increased with the increase in C(sus), and the fractional residence time of cells in individual segments approached a constant. This means that a high concentration of neutrophils facilitates their uniform distribution in the network. However, the ratio between the time-averaged concentration of the cells in the network and C(sus) decreased and our numerical simulation did not reach the experimentally obtained value. This implies that, in a real alveolar capillary bed, plasma leaks through the plugged segments or that the capillary network has bypasses through which the plasma can flow. (C) 2008 Elsevier B.V. All rights reserved.
- Frictional characteristics of erythrocytes on coated glass plates subject to inclined centrifugal forces, Takashi Kandori, Toshiyuki Hayase, Kousuke Inoue, Kenichi Funamoto, Takanori Takeno, Makoto Ohta, Motohiro Takeda, Atsushi Shirai, JOURNAL OF BIOMECHANICAL ENGINEERING-TRANSACTIONS OF THE ASME, JOURNAL OF BIOMECHANICAL ENGINEERING-TRANSACTIONS OF THE ASME, 130(5), 051007-1 - 051007-8, Oct. 2008 , RefereedSummary:In recent years a diamond-like carbon (DLC) film and a 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer have attracted attention as coating materials for implantable artificial organs or devices. When these materials are coated on vascular devices, compatibility to blood is an important problem. The present paper focuses on friction characteristics of erythrocytes to these coating materials in a medium. With an inclined centrifuge microscope developed by the authors, observation was made for erythrocytes moving on flat glass plates with and without coating in a medium of plasma or saline under the effect of inclined centrifugal force. Friction characteristics of erythrocytes with respect to these coating materials were then measured and compared to each other to characterize DLC and MPC as coating materials. The friction characteristics of erythrocytes in plasma using the DLC-coated and noncoated glass plates are similar, changing approximately proportional to the 0.5th power of the cell velocity. The cells stick to these plates in saline as well, implying the influence of plasma protein. The results using the MPC-coated plate in plasma are similar to those of the other plates for large cell velocities, but deviate from the other results with decreased cell velocity. The results change nearly proportional to the 0.75th power of the cell velocity in the range of small velocities. The results for the MPC-coated plate in saline are similar to that in plasma but somewhat smaller, implying that the friction characteristics for the MPC-coated plate are essentially independent of plasma protein.
- Deformations of thin liquid spherical shells in liquid-liquid-gas systems, Satoyuki Kawano, Atsushi Shirai, Shohei Nagasaka, PHYSICS OF FLUIDS, PHYSICS OF FLUIDS, 19(1), Article 012105, Jan. 2007 , RefereedSummary:Deformation characteristics of a millimeter-sized thin liquid spherical shell moving at intermediate Reynolds numbers in immiscible liquid are investigated both numerically and experimentally. Experiments are made using the novel principle of sequential production of the shell developed by the authors. Numerical results of the flow pattern around the liquid shell, deformation ratio, and the drag coefficient are compared to experimental results for wide flow conditions. They are in reasonable agreement from the viewpoint of practical engineering. Furthermore, effects of shell deformation on heat transfer characteristics are also investigated numerically. The present research provides the fluid dynamical knowledge for various applications of liquid spherical shells. (c) 2007 American Institute of Physics.
- Numerical simulation of flow for viscoelastic neutrophil models in a rectangular capillary network: Effects of capillary shape and cell stiffness on transit time, Atsushi Shirai, Ryo Fujita, Toshiyuki Hayase, Technology and Health Care, Technology and Health Care, 15(2), 131 - 146, 2007 , RefereedSummary:The concentration of neutrophils in the pulmonary microvasculature is higher than in large systemic vessels. It is thought that the high concentration of neutrophils facilitates their effective recruitment to sites of inflammation. Thus, in order to understand the role of neutrophils in the immune system, it is important to clarify their flow characteristics in the pulmonary microvasculature. In a previous study, we developed a model to simulate the flow of neutrophils in a capillary network, in which the cells were modeled as spheres of a Maxwell material with a cortical tension and the capillary segments were modeled as arc-shaped constrictions in straight pipes. In the present paper, the flow of neutrophils in a simplified alveolar capillary network model is investigated for various constriction shapes and cell stiffnesses. Finally, it is shown that both the coefficient of variation of the transit time of the cells, which is the standard deviation divided by the mean transit time, and the mean transit time increase as the capillary segments become steep or tight, or when the cells become hard. The mean value of the transit time exceeds the median for all of the conditions that occur in real lungs, although the difference between them is small. © 2007 - IOS Press and the authors. All rights reserved.
- Numerical simulation of noninvasive blood pressure measurement, Satoru Hayashi, Toshiyuki Hayase, Atsushi Shirai, Masaru Maruyama, JOURNAL OF BIOMECHANICAL ENGINEERING-TRANSACTIONS OF THE ASME, JOURNAL OF BIOMECHANICAL ENGINEERING-TRANSACTIONS OF THE ASME, 128(5), 680 - 687, Oct. 2006 , RefereedSummary:In this paper a simulation model based on the partially pressurized collapsible tube model for reproducing noninvasive blood pressure measurement is presented. The model consists of a collapsible tube, which models the pressurized part of the artery, rigid pipes connected to the collapsible tube, which model proximal and distal region far from the pressurized part, and the Windkessel model, which represents the capacitance and the resistance of the distal part of the circulation. The blood flow is simplified to a one-dimensional system. Collapse and expansion of the tube is represented by the change in the cross-sectional area of the tube considering the force balance acting on the tube membrane in the direction normal to the tube axis. They are solved using the Runge-Kutta method. This simple model can easily reproduce the oscillation of inner fluid and corresponding tube collapse typical for the Korotkoff sounds generated by the cuff pressure. The numerical result is compared with the experiment and shows good agreement.
- Fundamental study of ultrasonic-measurement-integrated simulation of real blood flow in the aorta, K Funamoto, T Hayase, A Shirai, Y Saijo, T Yambe, ANNALS OF BIOMEDICAL ENGINEERING, ANNALS OF BIOMEDICAL ENGINEERING, 33(4), 415 - 428, Apr. 2005 , RefereedSummary:Acquisition of detailed information on the velocity and pressure fields of the blood flow is essential to achieve accurate diagnosis or treatment for serious circulatory diseases such as aortic aneurysms. A possible way to obtain such information is integration of numerical simulation and color Doppler ultrasonography in the framework of a flow observer. This methodology, namely, Ultrasonic-Measurement-Integrated (UMI) Simulation, consists of the following processes. At each time step of numerical simulation, the difference between the measurable output signal and the signal indicated by numerical simulation is evaluated. Feedback signals are generated from the difference, and numerical simulation is updated applying the feedback signal to compensate for the difference. This paper deals with a numerical study on the fundamental characteristics of UMI simulation using a simple two-dimensional model problem for the blood flow in an aorta with an aneurysm. The effect of the number of feedback points and the feedback formula are investigated systematically. It is revealed that the result of UMI simulation in the feedback domain rapidly converges to the standard solution, even with usually inevitable incorrect upstream boundary conditions. Finally, an example of UMI simulation with feedback from real color Doppler measurement also shows a good agreement with measurement.
- Numerical realization for analysis of real flows by integrating computation and measurement, T Hayase, K Nisugi, A Shirai, INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, 47(6-7), 543 - 559, Feb. 2005 , RefereedSummary:In this paper, we deal with a numerical realization, which is a numerical analysis methodology to reproduce real flows by integrating numerical simulation and measurement. It is difficult to measure or calculate field information of real three-dimensional unsteady flows due to the lack of an experimental field measurement method, as well as of a way to specify the exact boundary or initial conditions in computation. Based on the observer theory, numerical realization is achieved by a combination of numerical simulation, experimental measurement, and a feedback loop to the simulation from the output signals of both methods. The present paper focuses on the problem of how an inappropriate model or insufficient grid resolution influences the performance of the numerical realization in comparison with ordinary simulation. For a fundamental flow with the Karman vortex street behind a square cylinder, two-dimensional analysis is performed by means of numerical realization and ordinary simulation with three grid resolutions. Comparison of the results with those of the experiment proved that the feedback of the experimental measurement significantly reduces the error due to insufficient grid resolution and effectively reduces the error due to inappropriate model assuming two-dimensionality. Copyright (C) 2004 John Wiley Sons, Ltd.
- Simulation model for flow of neutrophils in pulmonary capillary network, Atsushi Shirai, Ryo Fujita, Toshiyuki Hayase, Technology and Health Care, Technology and Health Care, 13(4), 301 - 311, 2005 , RefereedSummary:The concentration of neutrophils in the pulmonary microvasculature is higher than in systemic large vessels. It is thought that the high concentration of neutrophils facilitates their effective recruitment to sites of inflammation. Thus, in order to understand the role of neutrophils in the immune system, it is important to clarify their flow characteristics in the pulmonary microvasculature. In previous studies, we numerically investigated the motion of a neutrophil through a single capillary segment modeled by a moderate axisymmetric constriction in a straight pipe, developing a mathematical model for the prediction of the transit time of the cell through the segment. In the present study, this model was extended for application to network simulation of the motion of neutrophils. First, we numerically investigated shape recovery of a neutrophil after expulsion from a narrow capillary segment. This process was modeled in two different phases: elastic recovery and viscous recovery. The resulting model was combined with the previously developed models to simulate motion of the cells and plasma flow in a capillary network. A numerical simulation of the motion of neutrophils and plasma flow in a simple lattice capillary network showed that neutrophils were widely dispersed in the network with an increased concentration. © 2005 - IOS Press and the authors. All rights reserved.
- Fundamental study of aerodynamic drag reduction for vehicle with feedback flow control, K Nisugi, T Hayase, A Shirai, JSME INTERNATIONAL JOURNAL SERIES B-FLUIDS AND THERMAL ENGINEERING, JSME INTERNATIONAL JOURNAL SERIES B-FLUIDS AND THERMAL ENGINEERING, 47(3), 584 - 592, Aug. 2004 , RefereedSummary:The present paper deals with a fundamental study of aerodynamic drag reduction for a vehicle with a feedback flow control. As the first step, two-dimensional calculation was performed for a flow around a simplified vehicle model. The mechanism of unsteady drag was investigated in relation to the vortex shedding from the model. The location of the control flow nozzle was so determined that the control flow influences the drag most effectively. The key in designing the present feedback control is the definition of the output signal. Based on the physical consideration of the drag generation, the location of the output velocity measurement was changed within a limited region near the front windshield. A systematic calculation revealed that the output signal defined in a small region results in a significant drag reduction of 20% with respect to the case without control. The present feedback flow control is generally applicable to the drag reduction of the bluff body for which the drag is generated under the same mechanism of essentially two-dimensional vortex shedding.
- Fundamental study of hybrid wind tunnel integrating numerical simulation and experiment in analysis of flow field, K Nisugi, T Hayase, A Shirai, JSME INTERNATIONAL JOURNAL SERIES B-FLUIDS AND THERMAL ENGINEERING, JSME INTERNATIONAL JOURNAL SERIES B-FLUIDS AND THERMAL ENGINEERING, 47(3), 593 - 604, Aug. 2004 , RefereedSummary:This paper deals with a new flow analysis system, namely the hybrid wind tunnel, which integrates the experimental measurement with a wind tunnel and a corresponding numerical simulation with a computer. Analysis here is performed for the fundamental flow with the Karman vortex street in a wake of a square cylinder. A specific feature of the hybrid wind tunnel is existence of the feedback signal to compensate the error in the pressure on the side walls of the cylinder and the feed-forward signal to adjust the upstream velocity boundary condition. Investigation is focused on evaluating the hybrid wind tunnel as a flow analysis methodology with respect to the ordinary simulation and the experiment. As compared with the ordinary simulation, the hybrid wind tunnel substantially improves the accuracy and the efficiency in the analysis of the flow. Especially, the oscillation of the flow due to the Karman vortex street reproduced with the hybrid wind tunnel exactly synchronizes with that of the experiment; while that with the ordinary simulation never behave like that. In comparison with the experiment, the hybrid wind tunnel provides more detailed information of the flow than the experiment does.
- Two-dimensional computational flow analysis and frictional characteristics model for red blood cell under inclined centrifuge microscopy, K Funamoto, T Hayase, A Shirai, JSME INTERNATIONAL JOURNAL SERIES C-MECHANICAL SYSTEMS MACHINE ELEMENTS AND MANUFACTURING, JSME INTERNATIONAL JOURNAL SERIES C-MECHANICAL SYSTEMS MACHINE ELEMENTS AND MANUFACTURING, 46(4), 1304 - 1311, Dec. 2003 , RefereedSummary:Simplified two-dimensional flow analysis is performed in order to simulate frictional characteristics measurement of red blood cells moving on a glass plate in a medium with an inclined centrifuge microscope. Computation under various conditions reveals the influences of parameters on lift, drag, and moment acting on a red blood cell. Among these forces, lift appears only when the cell is longitudinally asymmetric. By considering the balance of forces, the frictional characteristics of the red blood cell are modeled as the sum of Coulomb friction and viscous drag. The model describes the possibility that the red blood cell deforms to expand in the front side in response to the inclined centrifugal force. When velocity exceeds some critical value, the lift overcomes the normal centrifugal force component, and the thickness of the plasma layer between the cell and the glass plate increases from the initial value of the plasma protein thickness.
- Transit characteristics of a neutrophil passing through two moderate constrictions in a cylindrical capillary vessel - (Effect of cell deformation on transit through the second constriction), A Shirai, R Fujita, T Hayase, JSME INTERNATIONAL JOURNAL SERIES C-MECHANICAL SYSTEMS MACHINE ELEMENTS AND MANUFACTURING, JSME INTERNATIONAL JOURNAL SERIES C-MECHANICAL SYSTEMS MACHINE ELEMENTS AND MANUFACTURING, 46(4), 1198 - 1207, Dec. 2003 , RefereedSummary:Neutrophils must flow through the pulmonary capillary network in a deformed shape because pulmonary capillaries are closely interconnected, and deformed neutrophils take about 15 s to 1 min to return to their resting spherical shape. In this paper, flow of a neutrophil through two moderate constrictions in a pipeline is numerically investigated, focusing on the effect of cell deformation on the cell's transit time through the constrictions. Changing sizes and positions of the constrictions, we found that the maximum cell radius at the entrance of the constriction and the throat radius of the constriction are the dominant factors in predicting the cell's transit time through the constriction. When the difference between these two radii is relatively large, steeper constriction (smaller radius of curvature) increases the transit time, but this tendency is reversed when the difference is small. Cells traverse the constriction without delay when the maximum cell radius and throat radius are comparable. Finally, we present a simple mathematical model for the transit time.
- Transit characteristics of a neutrophil passing through a circular constriction in a cylindrical capillary vessel (effect of mechanical properties of the cell and constriction geometry), A Shirai, R Fujita, T Hayase, JSME INTERNATIONAL JOURNAL SERIES C-MECHANICAL SYSTEMS MACHINE ELEMENTS AND MANUFACTURING, JSME INTERNATIONAL JOURNAL SERIES C-MECHANICAL SYSTEMS MACHINE ELEMENTS AND MANUFACTURING, 45(4), 974 - 980, Dec. 2002 , RefereedSummary:The former analysis of neutrophil's transit through pulmonary capillary network used the result of a micropipette aspiration experiment to model the transit in single capillary segment despite blunt tip geometry of the pipette is largely different from the real capillary segment. In the previous work, we have numerically investigated the transit of passive and fMLP-stimulated neutrophils through an arc-shaped constriction, establishing the analytical expression for the transit time. This paper intends to give a simplified model for the transit of a neutrophil through a capillary segment based on the numerical analysis and the stress-strain relationship of a Maxwell material. It is shown that the transit time is in proportion to the viscosity of the cell and in inverse proportion to the square root of the curvature radius of the constriction. The definition of the driving pressure of the cell into a micropipette is also applicable to that into the constriction.
- Neutrophil transit times through pulmonary capillaries: The effects of capillary geometry and fMLP-stimulation, M Bathe, A Shirai, CM Doerschuk, RD Kamm, BIOPHYSICAL JOURNAL, BIOPHYSICAL JOURNAL, 83(4), 1917 - 1933, Oct. 2002 , RefereedSummary:The deformations of neutrophils as they pass through the pulmonary microcirculation affect their transit time, their tendency to contact and interact with the endothelial surface, and potentially their degree of activation. Here we model the cell as a viscoelastic Maxwell material bounded by constant surface tension and simulate indentation experiments to quantify the effects of (N-formyl-L-methionyl-L-leucyl-L-phenylalanine (fMLP)-stimulation on its mechanical properties (elastic shear modulus and viscosity). We then simulate neutrophil transit through individual pulmonary capillary segments to determine the relative effects of capillary geometry and fMLP-stimulation on transit time. Indentation results indicate that neutrophil viscosity and shear modulus increase by factors of 3.4, for 10(-9) M fMLP, and 7.3, for 10(-6) M fMLP, over nonstimulated cell values, determined to be 30.8 Pa.s and 185 Pa, respectively. Capillary flow results indicate that capillary entrance radius of curvature has a significant effect on cell transit time, in addition to minimum capillary radius and neutrophil stimulation level. The relative effects of capillary geometry and fMLP on neutrophil transit time are presented as a simple dimensionless expression and their physiological significance is discussed.
- Three-dimensional flow analysis in VFP type artificial heart by unstructured grid, Satoyuki Kawano, Takuma Kato, Kazuhiro Nakahashi, Atsushi Shirai, Toshiyuki Hayase, Tomoyuki Yambe, Shin-Ichi Nitta, Hiroyuki Hashimoto, American Society of Mechanical Engineers, Pressure Vessels and Piping Division (Publication) PVP, American Society of Mechanical Engineers, Pressure Vessels and Piping Division (Publication) PVP, 448(1), 229 - 238, 2002 , RefereedSummary:To effectively design the vibrating flow pump (VFP) for left ventricular assist device, the numerical codes were developed for three-dimensional blood flow based on the finite volume method. The numerical codes were also developed based on the artificial compressibility method by the use of unstructured grid. Three-dimensional numerical computations and the visualizations were made for flow patterns in the casing of VFP, which were closely connected with hemolysis and blood coagulation. We examined the three different inlet conditions, i.e., radial flow, flow considering the 2nd vibration mode of the jellyfish valve motion, and the swirling flow, to explore the suitable condition for preventing the hemolysis and the blood coagulation. It was found that the swirling flow could effectively decrease hemolysis. The effect of rhenlogy model of the blood flow was also studied in detail.
- Static and dynamic characteristics of a pressure-compensated flow control, S Hayashi, A Shirai, NN Guo, T Hayase, PROCEEDINGS OF THE FIFTH INTERNATIONAL CONFERENCE ON FLUID POWER TRANSMISSION AND CONTROL (ICFP'2001), PROCEEDINGS OF THE FIFTH INTERNATIONAL CONFERENCE ON FLUID POWER TRANSMISSION AND CONTROL (ICFP'2001), 156 - 160, 2001 , RefereedSummary:This paper deals with static and dynamic characteristics of a pressure-compensated flow control valve for water hydraulic use by Danfoss. A mathematical model is derived and numerical simulation is performed, in particular, the stability of the circuit including the valve is analyzed. As a result, it is shown that the circuit becomes unstable depending upon the pipeline length connected to the valve, and that the upstream pipeline length is especially sensible to stability.

- Computer Aided Flow Visualization and Arimation of Three-Dimensional Solid-Liquid Two-Phase Jet at Low Reynolds Numbers, Hiroyuki Hashimoto, Satoyuki Kawano, Atsushi Shirai, Akio Ihara, Tatsuya Yamamoto, Joint author, 1995 04 Summary:Multiphase Flow '95-Kyotoにおける発表原稿から抜粋した論文を編集したもの． Editors: A. Serizawa, T. Fukano and J. Bataille

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- 傾斜遠心力作用下における好中球様細胞の挙動解析, 日本機械学会P-SCC12（高度物理刺激と生体応答に関する研究分科会)第8回分科会, 2015 01 20
- 押しつけ力がP-selectin上でのHL-60の移動特性に与える影響, 日本機械学会第27回バイオエンジニアリング講演会, 2015 01
- 鍼治療における血行動態の数学モデル構築 -太衝への刺鍼による血行動態変化の再現-, 日本機械学会第27回バイオエンジニアリング講演会, 2015 01
- On the Motility and Locomotive Organs of Beach Flea, The Sixth International Symposium on Aero Aqua Bio-Mechanisms (ISABME2014), 2014 11
- 固体平板と水面でのトビムシの跳躍挙動における比較, 日本流体力学会年会2014, 2014 09
- 脈診における脈波同時計測システムの開発 ―カフを用いたPVDFフィルムセンサによる脈波計測の定量化―, 日本機械学会東北支部第49期総会・講演会, 2014 03
- 傾斜遠心顕微鏡を用いた血球と固体壁との力学的相互作用の計測, 第98回岡山県医用工学研究会, 2014 02 12
- Fundamental characteristics of motion of neutrophil-lik HL-60 cells on glass plate, 2014 Annual ELyT Workshop, 2014 02
- HL-60の分化がガラス基板への付着性に与える影響, 日本機械学会第26回バイオエンジニアリング講演会, 2014 01
- Influence of differentiation of HL-60 cells on their motion on a flat glass plate, The 15th International Conference on Biomedical Engineering. (ICBME 2013), 2013 12
- 微小血管における好中球の挙動, 日本機械学会2013年度年次大会, 2013 09 11
- ガラス平板上におけるHL60の挙動に与える分化の影響に関する傾斜遠心顕微鏡を用いた実験的研究, 日本機械学会第25回バイオエンジニアリング講演会, 2013 01
- 分岐を考慮した腕部血管系一次元数学モデルにおける脈波の反射の検証, 日本機械学会2012年度年次大会, 2012 09
- 水棲微小生物の推進機構に関する数値解析（定常層流下における単一遊泳脚モデルの形状が推進力に与える影響）, 日本機械学会2012年度年次大会, 2012 09
- 植物流体力学としての花弁表面細胞の研究, 日本機械学会2012年度年次大会, 2012 09
- The Jump of the Globular Springtail and Jumping Mechanism Worked by a Spring, The 5th International Symposium on Aero Aqua Bio-mechanisms, 2012 08
- Influence of Pressing Force on Motion of HL60 Cells on HUVEC substrate, 18th Congress of the European Society of Biomechanics (ESB2012), 2012 07
- Dynamics in Motion of Dandelion Flower Head, 15th International Conference on Experimental Mechanics (ICEM15), 2012 07
- Motion of fMLP-Stimulated HL60 Cells on HUVEC Cultured on a Flat Glass Plate, 26th International Conference on Surface Modification Technologies (SMT26), 2012 06
- Behavior of HL60 cells on HUVEC substrate under inclined centrifugal forces, 2012 Annual ELyT Workshop, 2012 03
- トビムシの水面上での跳躍, 日本機械学会東北支部第47期総会・講演会, 2012 03
- ハマトビムシのロコモーション・メカニズム, 日本機械学会東北支部第47期総会・講演会, 2012 03
- HUVEC基板上を移動するHL60に対する押しつけ力の影響, 日本機械学会第24回バイオエンジニアリング講演会, 2012 01
- ガラス平板上におけるHL60の挙動に与えるfMLP刺激の影響に関する傾斜遠心顕微鏡を用いた実験的研究, 日本機械学会第24回バイオエンジニアリング講演会, 2012 01
- 傾斜遠心顕微鏡下での赤血球の浮上機構に関する数値解析 第2報：剛体赤血球モデルによる摩擦特性の再現性の検討, 日本機械学会第24回バイオエンジニアリング講演会, 2012 01
- ガラス平板上におけるHL60の挙動に与えるfMLP刺激の影響に関する傾斜遠心顕微鏡を用いた実験的研究, 日本機械学会第24回バイオエンジニアリング講演会, 2012 01
- HUVEC基板上を移動するHL60に対する押しつけ力の影響, 日本機械学会第24回バイオエンジニアリング講演会, 2012 01
- Contribution of Ulnar Artery to Numerical Reproduction of Indentation Experiment of Radial Artery for Scientific Verification of Pulse Diagnosis, 5th Asian Pacific Student Workshop on Nano-Biomedical Engineering, 2011 12
- Movement of Springtail in Air, Eighth International Conference on Flow Dynamics, 2011 11
- Observation of Fly Wings and Flight Behavior, Eighth International Conference on Flow Dynamics, 2011 11
- Springtail Jump on Water Surface, The Eleventh International Symposium on Advanced Fluid Information and Transdisciplinary Fluid INtegration, 2011 11
- 脈診を模擬した脈波計測の数値実験における尺骨動脈の影響, 日本機械学会第22回バイオフロンティア講演会, 2011 10
- Observation of Motion of HL60 Cells on HUVEC Cultured on a Flat Glass Plate using the Inclined Centrifuge Microscope, Takashi UMIMOTO, Haruka URANUMA, Toshiyuki HAYASE, ELyT Annual Workshop in Sendai 2011, 2011 02 22
- Observation of Motion of HL60 Cells on HUVEC Cultured on a Flat Glass Plate using the Inclined Centrifuge Microscope, ELyT Annual Workshop in Sendai 2011, 2011 02
- Observation of velocity of Antibody-modified HL60 cells on glass plates using the inclined centrifuge microscope, Hiroki SATO, Toshiyuki HAYASE, 4th East Asian Pacific Student Workshop on Nano-Biomedical Engineering, 2010 12 15
- 血管内皮細胞の配向方向が好中球の挙動に与える影響に関する実験的研究, 浦沼 晴香, 早瀬 敏幸, 日本機械学会第21回バイオフロンティア講演会, 2010 11 12
- Experimental Study on Effect of Direction of Endothelial Cells' Orientation on Motion of HL60 Cells, Haruka URANUMA, Toshiyuki HAYASE, The 7th International Conference on Flow Dynamics, 2010 11 01
- 傾斜遠心顕微鏡で撮影された連続画像のぶれ補正手法, 早瀬 敏幸, 日本流体力学会年会2010, 2010 09 09
- 傾斜遠心顕微鏡を用いたガラス平板上におけるHL60の微視的挙動に関する基礎的研究, 佐藤 博紀, 早瀬 敏幸, 日本機械学会2010年度年次大会, 2010 09 06
- A Stabilization Technique of Wobbly Images taken by the Inclined Centrifuge Microscope, Toshiyuki HAYASE, 6th World Congress of Biomechanics, 2010 08 01
- An Alligning Technique of Successive Images Taken by the Inclined Centrifuge Microscope, 2010 Annual ELyT Workshop, 2010 03 14
- 血管内皮細胞の配向が好中球の挙動に与える影響に関する実験的研究, 日本機械学会2009年度年次大会, 2009 09 14
- 健康度のわかる血管情報の可視化, 第8回情報科学技術フォーラム, 2009 09 02
- 傾斜遠心顕微鏡を用いた好中球の内皮細胞に対する摩擦特性の計測, 日本機械学会第21回バイオエンジニアリング講演会, 2009 01
- 脈診の科学的検証のための一次元数学モデルを用いた脈波計測実験の再現, 日本機械学会第21回バイオエンジニアリング講演会, 2009 01
- Multi-Scale Bio-Fluid Researches in IFS, ELyT Lab. Workshop and Signing Ceremony, 2008 12 02
- Measurement of Friction Characteristics of Neutrophils on MPC Polymer with the Inclined Centrifuge Microscope, GPBE/NUS-Tohoku Graduate Student Conference in Bioengineering, 2008 12
- Reproduction of Pulse Waveform Measurement using One-dimensional Mathematical Model for Validation of Pulse Diagnosis, GPBE/NUS-Tohoku Graduate Student Conference in Bioengineering, 2008 12
- Flow and Friction Characteristics of Neutrophils, IFS, Tohoku Univ. – Tsinghua Univ. Joint Workshop, 2008 10 27
- 第2回：血液の流れ, 平成20年度みやぎ県民大学 東北大学流体科学研究所開放講座～流れを科学する～, 2008 09 19
- 傾斜遠心顕微鏡を用いた好中球のMPCポリマーに対する摩擦特性の計測, 日本機械学会第19回バイオフロンティア講演会, 2008 09
- 脈診の科学的検証のための腕部皮下組織の力学モデルの検討, 中西勉, 鳴海賢太郎, 白井敦, 早瀬敏幸, JACT-JIM合同大会2007 in 松島, 2007 12 01
- 肺毛細血管網における好中球の停滞時間が濃度上昇に与える影響, 白井敦, 早瀬敏幸, (社)日本機械学会創立110周年記念2007年度年次大会, 2007 09 10
- EFFECT OF RETENTION TIME OF NEUTROPHILS IN ALVEOLAR CAPILLARIES ON INCREASE IN THEIR CONCENTRATION IN THE CAPILLARY NETWORK, Atsushi SHIRAI, Toshiyuki HAYASE, 5th Joint ASME/JSME Fluids Engineering Conference, 2007 07 30
- EFFECT OF NEUTROPHILS RETENTION TIME IN CAPILLARIES ON INCREASE IN THEIR CONCENTRATION IN A LATTICE CAPILLARY NETWORK, Atsushi SHIRAI, Toshiyuki HAYASE, ASME 2007 Summer Bioengineering Conference, 2007 07 20
- 脈診における脈波情報の取得に関する数学モデルの構築と実験による検証, 鳴海賢太郎, 中西勉, 劉磊, 井上浩介, 白井敦, 早瀬敏幸, 太田信, 金野敏, 川田浩, 丸山満也, 白石泰之, 仁田新一, 日本機械学会第17回バイオフロンティア講演会, 2006 11 11 Summary:発表：鳴海
- 微小流路における好中球の流動観察システムの改良（MPCコーティングによる血球の流路への付着防止）, 朝比奈翔, 白井敦, 早瀬敏幸, 日本機械学会第17回バイオフロンティア講演会, 2006 11 11 Summary:発表：朝比奈
- 好中球の物性が毛細血管網の通過時間に与える影響, 白井敦, 早瀬敏幸, 第84期日本機械学会流体工学部門講演会, 2006 10 28
- 矩形流路における好中球の流動に関する数値解析（流路断面形状が通過時間に与える影響）, 白井敦, 増田直, 早瀬敏幸, 日本機械学会2006年度年次大会, 2006 09 19
- 肺毛細血管網における好中球の流動シミュレーション, 21世紀COEプログラム 平成18年度第4回医工共同開催講義, 2006 09 12
- Numerical simulation of 3-D deformation of a neutrophil in a rectangular microchannel, Atsushi SHIRAI, Sunao MASUDA, Toshiyuki HAYASE, 5th World Congress of Biomechanics, 2006 07 29
- 3-D NUMERICAL SIMULATION OF FLOW OF A NEUTROPHIL FOR THE RETENTION TIME IN A MODERATE CONSTRICTION OF A RECTANGULAR MICROCHANNEL, Atsushi SHIRAI, Sunao MASUDA, Toshiyuki HAYASE, ASME 2006 Summer Bioengineering Conference, 2006 06 21
- Moderate Constriction Model for Neutrophils Flow in Pulmonary Capillaries, The 12th International Conference on Biomedical Engineering (ICBME 2005), 2005 12 07 Summary:Held as the 7th International Symposium of Future Medical Engineering Based on Bio-nanotechnology In the 12 the International Conference on Biomedical Engineering (ICBME 2005).
- Numerical Simulation for Spatial Distribution of Neutrophils in a Capillary Network, Toshiyuki HAYASE, The 6th International Symposium on Future Medical Engineering based on Bio-nanotechnology (21st Century COE Program), 2005 11 21
- 毛細血管ネットワークにおける好中球濃度の上昇に関する数値解析, 早瀬敏幸, 日本機械学会 第16回バイオフロンティア講演会, 2005 11 10
- 肺の毛細血管網を対象とした好中球流動のシミュレーションモデル開発, 藤田 亮, 早瀬敏幸, 日本生体医工学会 第106回バイオメカニクス研究会, 2005 09 29
- 微小流路の断面形状が好中球の流動特性に与える影響の数値解析, 増田直, 早瀬敏幸, 日本機械学会2005年度年次大会, 2005 09 19 Summary:発表：増田
- 毛細血管ネットワークにおける好中球の濃度分布に関する数値解析, 早瀬敏幸, 日本流体力学会年会2005, 2005 09 05
- Three-Dimensional Numerical Analysis of Plasma Flow around a Neutrophil in a Microchannel, S. Masuda, T. Hayase, ASME 2005 Summer Bioengineering Conference, 2005 06 22
- FLOW SIMULATION ON NEUTROPHILS IN CAPILLARY NETWORK (EFFECT OF CAPILLARY GEOMETRY ON TRANSIT OF CELLS THROUGH NETWORK), Ryo FUJITA, Toshiyuki HAYASE, The Third IASTED International Conference on Biomedical Engineering (BioMED 2005), 2005 02 16
- Effect of Cell Stiffness on Transit Through Pulmonary Capillary Network, Thr Fourth International symposium on Advanced Fluid Information and The First International Symposium on Transdisciplinary Fluid Integration, 2004 11 11
- Numerical Analysis for Affect of Neutrophil Shape on Transit Through Capillaries, Third International Symposium on Advanced Fluid Information (AFI-2003), 2003 11 21
- TRANSIT CHARACTERISTICS OF A DEFORMED NEUTROPHIL THROUGH A MODERATE CONSTRICTION, 2003 ASME International Mechanical Engineering Conference (IMECE 2003), 2003 11 15
- Transit time of a deformed neutrophil through a pulmonary capillary segment, The First International workshop on Hierarchical Life Cycle Evaluation of Complex Systems and The sixth International Workshop on Intelligent Fluid and materials Systems, 2002 12 05
- FLOW AND DEFORMATION OF A NEUTROPHIL PASSING THROUGH A CONSTRICTION IN A FINE CAPILLARY, The Fifth JSME-KSME Fluids Engineering Conference, 2002 11 17
- EFFECT OF CONSTRICTION GEOMETRY ON TRANSIT OF DEFORMED NEUTROPHILS IN CAPILLARIES, VI World Congress Biomechanics, 2002 08 04
- 微小血管における血漿流動と血球変形の連成問題, Multidisciplinary Lecture Series 5, 2002 03 25 Summary:日本機械学会 計算力学部門「流体と構造の複合問題研究会」・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」共同企画
- The Effect of Neutrophil Activation on Transit Time through Pulmonary Capillaries, The First Internaional Symposium on Advanced Fluid Information (AFI-2001), 2001 10 04
- EIGENVALUE ANALYSIS OF DIRECT-ACTING POPPET VALVE CIRCUIT, The Forth JHPS International Symposium, 1999 11 15
- Computer Aided Flow Visualization and Animation of Three-Dimensional Solid-Liquid Two-Phase Jet at Lowr Reynolds Numbers, The 2nd International Conference on Multiphase Flow '95-Kyoto, 1995 04 03
- APPLICABILITY OF LUBRICATION THEORY TO BLOOD CELLS MOTION IN FINE CAPILLARIES, The Third JSME-KSME Fluids Engineering Conference, 1994 07 25

- 接触力を考慮した好中球のrolling特性解析 ―傾斜遠心顕微鏡を用いたin vitro計測―, 白井 敦, 海本 隆志, 可視化情報学会誌, 34, 134, 22, 27, 2014 07
- 東北大学流体科学研究所附属流体融合研究センター, 白井 敦, 計測と制御, 48, 3, 288, 289, 2009 03
- 有限要素法による流れ解析, 白井敦, フルードパワーシステム, 33, 7, 420, 425, 2002 11
- 肺の毛細血管における血漿流動と好中球変形の連成問題, 白井敦, 日本数値流体力学会誌, 9, 4, 106, 111, 2001 08
- Modeling neutrophil transport in pulmonary capillaries, Atsushi Shirai, RESPIRATORY PHYSIOLOGY & NEUROBIOLOGY, 163, 1-3, 158, 165, 2008 11 , 10.1016/j.resp.2008.06.015Summary:Neutrophils can be retained in the pulmonary microvasculature due to their low deformability, resulting in having a higher concentration there than in the systemic circulation, even in normal lungs. It is thought that this high concentration of the cells facilitates their effective recruitment to sites of inflammation. Thus, in order to understand their role in the immune system in the lungs, where blood comes in contact with outer air via thin septa of alveoli, it is important to clarify their flow characteristics in the pulmonary capillary bed. However, in contrast to erythrocytes in systemic capillaries, little research has been performed on the flow of neutrophils in pulmonary capillaries. This may be partly because no complete rheological model of the cell has been established yet, and partly because pulmonary capillaries are very short and closely interconnected, forming a complicated three-dimensional network, in addition to difficulty in in vivo experimental observations. Moreover, the neutrophils change their mechanical properties and show active motion in response to some chemoattractants. In this article, various proposed rheological models of the neutrophil, flow models of a cell through a single capillary segment, and alveolar capillary network models are introduced, aiming at the numerical simulation of neutrophil transport in the pulmonary microvasculature. (C) 2008 Elsevier B.V. All rights reserved.

- 連続血圧測定システム、連続血圧測定方法、連続血圧測定プログラムおよび、連続血圧測定プログラムを記録したコンピュータ読み取り可能な記録媒体, 白井敦, 早瀬敏幸, 特願2011-284770, 特開2013-132407, 5750805
- 血管固さ評価装置、血管固さ評価方法、血管固さ評価プログラムおよび血管固さ評価プログラムを記録したコンピュータ読み取り可能な記録媒体, 白井敦, 中西勉, 松野史子, 早瀬敏幸, 特願2011-233050, 特開2013-90664, 5751540
- 血流可視化診断装置, 早瀬敏幸, 船本健一, 白井敦, 山家智之, 西條芳文, 2002-293631, 2004-121735

- 2007 04 16 , (社)日本機械学会, 日本機械学会賞(論文), Transit Characteristics of a Neutrophil Passing through Two Moderate Constrictions in a Cylindrical Capillary Vessel (Effect of Cell Deformation on Transit through the Second Constriction)
- 2002 03 26 , (財)トーキン科学技術振興財団, (財)トーキン科学技術振興財団 第12回(平成13年度)研究奨励賞, 微小血管系における白血球の流動制御に関する研究

- 2014 04 , 鍼刺激による血流動態変化の検証, 伝統中国医学の一つである鍼治療において，刺鍼による刺激が血行動態に影響を与えることが実験的に確かめられた．しかし，その機序についてはまだ仮定の段階であるため，数値解析によって物理的側面から刺鍼による血行動態変化を解析する．
- 2013 04 , 血管内皮細胞の表面幾何形状が好中球のローリングに与える影響に関するin vitro実験, 好中球の免疫反応プロセスにおいて，血管内非常におけるローリング挙動が最初期の反応として注目されている．これまでは接着分子の寄与に注目した研究が殆どであったが，血管内皮表面の幾何形状もその挙動に大きな影響を与えると考えられる．そこで，PDMSを用いてこの表面形状を模擬し，好中球の挙動に与える表面形状の影響を実験的に解析する．
- 2011 10 , 水棲微生物の推進に関する数値解析, 数mmから数cmオーダの水棲微生物に特有な繊毛を有する遊泳脚の推進機構を解明する．
- 2007 10 , 先進予防型健康社会仙台クラスター, 近年の少子・高齢化社会の急速な進展は，対応する社会システムやインフラの整備が追いつかない中で，医療費・介護費等の増加が指摘されている．こうした中で，コスト増を防ぎつつ市民の安全，安心かつ健康な生活を実現するためには，これまでの疾病等にかかってからの治療(2次，3次予防)に替えて，疾病等の発生そのものを予防する1次予防の取り組みを強化する必要がある．そこで，東北大学，東北福祉大学等の先端的な研究資源を活用し，先進的な予防の実現に資する研究開発，実証を行うことで先進的疾病予防・健康維持に関する知見の集積およびそれを活用した疾病予防・健康維持のためのサービス・機器開発を目指す産業の形成を図り，これによって市民の健康の質の向上，行政コストの効率化および地域経済の活性化をバランス良く成立させることを目指します．
- 2006 12 , 高精度血球変形観察システム, ハイスピードビデオカメラを用いた微小流路における血球流動観察システムの開発
- 2006 12 , PDMS微小流路作成システム, PDMSによる微小流路を作成する
- 2006 10 , 超音波計測連成解析による超高精度生体機能計測システム, 機器開発プログラム(領域特定型)「ハードウェアによる計測限界を突破するためのコンピュータ融合型計測分析システム」
- 2006 09 , 超音波を利用した非侵襲的骨切除システムの開発, 超音波を利用して非侵襲的に骨を切除するシステムの開発
- 2005 08 , 脈診を参考にした，脈波計測による病変診断システムの開発, 脈波計測による病変診断システム開発において，腕部血管系の血流シミュレーションモデル構築
- 2003 04 , 血球流動観察システム, 平成14年度からの継続
- 2002 04 , 微小血管における好中球の流動特性および変形挙動に関する実験的研究, 顕微鏡下における好中球流動および変形能の観察
- 2002 04 , 血球流動観察システム, 顕微鏡下における血球の流動特性を観察するシステムの開発
- 2000 06 , 肺毛細血管内における好中球の流動特性に関する数値解析, 肺の毛細血管における好中球の流動特性の数値解析

- 平成25年度みやぎ県民大学 東北大学流体科学研究所開放講座, Other, 2013 07 05 , 「血液の流れ」と題して，一般市民に対して血液の流れに関する講演を行った．
- 平成22年度みやぎ県民大学 東北大学流体科学研究所開放講座, Other, 2010 09 03 , 「第2回：血液の流れ」と題して，一般市民に対して血液の流れに関する講演を行った．
- ELyT Lab. Workshop and Signing Ceremony, Other, 2008 12 01 - 2008 12 02 , 東北大学さくらホールにて「Multi-Scale Bio-Fluid Researches in IFS」と題して流体研におけるバイオ関係の研究紹介を行った．
- IFS, Tohoku Univ. – Tsinghua Univ. Joint Workshop, Other, 2008 10 27 - 2008 10 28 , 中国精華大学において「Flow and Friction Characteristics of Neutrophils」と題して好中球の摩擦計測に関する講演を行った．
- 平成20年度みやぎ県民大学 東北大学流体科学研究所開放講座, Other, 2008 09 19 , 「第2回：血液の流れ」と題して，一般市民に対して血液の流れに関する講演を行った．
- 東北大学21世紀COE 第4回医工共同講義, Other, 2006 09 12 , 21世紀COEの関係で，「肺毛細血管網における好中球の流動シミュレーション」と題して好中球流動の数値解析に関する講演を行った．
- 日本生体医工学会 第106回バイオメカニクス研究会, Other, 2005 09 29 , 東北大学において，「肺の毛細血管網を対象とした好中球流動のシミュレーションモデル開発」と題して好中球流動の数値解析モデルに関する講演を行った．
- 「第６回知的流体・材料システムに関するワークショップ」および「第１回複雑システムの階層的ライフサイクル評価に関するワークショップ」, Other, 2002 12 05 - 2002 12 06 , 流体研会議室において，「Transit time of a neutrophil through a pulmonary capillary segment」と題して毛細血管における好中球の通過時間に関する講演を行った．
- Multidisciplinary Lecture Series 5, Other, 2002 03 25 , 日本機械学会計算力学部門「流体と構造の複合問題研究会」・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」共同企画(東北大学流体科学研究所共催)内のミニ企画として，「微小血管における血漿流動と血球変形の連成問題」と題して，流体研大講義室において血球変形と血漿流動の連成問題に関する講演を行った．