Details of the Researcher

PHOTO

Toshihiro Omori
Section
Graduate School of Engineering
Job title
Associate Professor
Degree

  • 博士（医工学）（東北大学）

  • 修士（工学）（東北大学）

Research History 3

  • 2023/10 - Present
    Tohoku University　Faculty of Engineering Department of Mechanical and Aerospace Engineering　Associate Professor

  • 2014/04 - 2023/09
    Tohoku University　Faculty of Engineering Department of Mechanical and Aerospace Engineering　Assistant Professor

  • 2012/04 - 2014/03
    Tohoku University　School of Engineering　Project Assistant Professor

Committee Memberships 11

  • 日本機械学会バイオエンジニアリング部門　運営委員

    2025/04 - Present

  • 日本機械学会バイオエンジニアリング部門　東北地区代議員

    2024/04 - Present

  • 日本機械学会バイオエンジニアリング部門　第35回バイオエンジニアリング講演会実行委員

    2023/06 - 2023/06

  • Bioengineering Division, The Japan Society of Mechanical Engineers　Exective Committee

    2018/04 - 2021/03

  • 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

    2018/04 - 2021/03

  • Bioengineering Division, The Japan Society of Mechanical Engineers　Publicity Committee

    2012/04 - 2014/03

  • 9th World Congress of Biomechanics　Session Moderator

    2022/07 -

  • The 11th Asian-Pacific Conference on Biomechanics　Program Committee

    2021/12 -

  • 日本機械学会バイオエンジニアリング部門　第31回バイオフロンティア講演会実行委員

    2020/12 -

  • 日本機械学会バイオエンジニアリング部門　第30回バイオフロンティア講演会実行委員

    2019/07 -

  • 日本機械学会バイオエンジニアリング部門　第26回バイオエンジニアリング講演会実行委員

    2014/01 -

Show all ︎Show first 5

Professional Memberships 2

  • American Physical Society

  • The Japan Society of Mechanical Engineers

Research Interests 1

  • Computational Biomechanics

Research Areas 3

  • Natural sciences / Bio-, chemical, and soft-matter physics /

  • Manufacturing technology (mechanical, electrical/electronic, chemical engineering) / Fluid engineering /

  • Life sciences / Biomedical engineering /

Awards 13

  1. Distinguished researcher

    2022/05　Tohoku University

  2. The Young Scientists’ Award

    2022/04　MEXT

  3. Papers of the Year 2018

    2019/04　Journal of Biomechanical Science and Engineering

  4. 青葉工学研究奨励賞

    2018/12　一般財団法人青葉工学振興会

  5. Yamaguchi Medal

    2017/07　Asian-Pacific Association for Biomechanics

  6. 瀬口賞

    2017/01　日本機械学会バイオエンジニアリング部門

  7. 日本機械学会奨励賞

    2014/04　日本機械学会

  8. Best Abstract Award

    2023/11　12th Asian Pacific Conference on Biomechanics

  9. Subject Collection in Comparative Biomechanics of Movement

    2020/03

  10. Outstanding Presentation 表彰

    2018/12　日本機械学会バイオエンジニアリング部門

  11. 第62回理論応用力学講演会優秀講演賞

    2013/03

  12. Presentation Award

    2009/12　3rd East-Asian Pacific Student Workshop on Nano-Biomedical Engineering

  13. Poster Finalist

    2008/09　Bioengineering 08

Show all ︎Show 5

Papers 56

  1. Capsule damage by an enclosed microswimmer Peer-reviewed

    Zhihan Huang, Toshihiro Omori, Takuji Ishikawa

    Journal of Fluid Mechanics　1013　A12　2025/06/13

    Publisher: Cambridge University Press (CUP)

    DOI： 10.1017/jfm.2025.10238 　

    ISSN： 0022-1120

    eISSN： 1469-7645

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    Capsules are widely used in bioengineering, chemical engineering and industry. The development of drug delivery systems using deformable capsules is progressing, yet the regulation of drug release within a capsule remains a challenge. Meanwhile, a microswimmer enclosed in a capsule can generate a large lubrication force on the capsule membrane, which could result in deformation and mechanical damage to the membrane. In this study, we numerically investigate how a capsule can be damaged by an enclosed microswimmer. The capsule membrane is modelled as a two-dimensional neo-Hookean material, with its deformability parametrised by capillary number. An isotropic brittle damage model is applied to express membrane rupture, with the Lighthill–Blake squirmer serving as the microswimmer model. In a sufficiently small capillary number regime, pusher-type squirmers exhibit stable swimming along the capsule membrane, while neutral-type and puller-type squirmers exhibit swimming towards the membrane and remain stationary. As capillary number increases, the damage to the membrane increases and rupture occurs in all swimming modes. For pusher-type squirmers, the critical capillary number leading to rupture is dependent on the initial incidence angle, whereas neutral-type and puller-type squirmers are independent of the initial value. Furthermore, we present methods for controlling membrane damage by magnetically orienting the microswimmer. The findings reveal that a static magnetic field can orient the microswimmer, leading to membrane damage and rupture even for a capsule that cannot be damaged by free swimming, while controlling the swimming path with a rotating magnetic field enables soft membranes to maintain deformation without rupture.

  2. Microstructure and deformation in suspensions of soft microswimmers Peer-reviewed

    Kiyoto Kubo, Toshihiro Omori, Takuji Ishikawa

    Journal of Fluid Mechanics　1011　A31　2025/05/13

    Publisher: Cambridge University Press (CUP)

    DOI： 10.1017/jfm.2025.7 　

    ISSN： 0022-1120

    eISSN： 1469-7645

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    In recent years, various unique properties of microswimmer suspensions have been revealed. Some microswimmers are deformable; however, the influence of the swimmer’s deformability has been overlooked. The present study examined the impact of soft microswimmers’ membrane deformations in a mono-dispersed dense suspension on microstructure formation. Due to the small size of the microswimmers, the flow field is described by the Stokes equation. The soft microswimmer was modelled as a capsule with a two-dimensional hyperelastic membrane enclosing a Newtonian fluid that is driven by propulsion torques distributed slightly above the membrane surface. Changes to the torque distribution caused the soft swimmer to exhibit different swimming modes as a pusher or puller. Similar to rigid squirmers, soft swimmers displayed self-organised local clusters in the suspension. Membrane deformation changed the mutual interference among swimmers in the cluster, bringing the interactions closer together than those of rigid squirmers. Especially among soft pushers, rotational diffusion due to hydrodynamic interference was reduced and the swimming trajectory became relatively straight. As a result, polar order was less likely to form, especially in regions of high $Ca$ . On the other hand, pullers showed strong interactions due to retraction flow and an increase in mean membrane tension. For pushers (pullers), the rear (side) interaction produced the greatest change in tension. These findings are expected to be useful for effort to understand the propulsion mechanisms of medical and industrial soft microrobots, as well as the biological responses of microorganisms induced by mechanical stimuli.

  3. Hydrodynamic confinement of bacteria within intestinal folds Peer-reviewed

    Jinyou Yang, Toshihiro Omori, Kenji Kikuchi, Takuji Ishikawa

    Proceedings of the Royal Society B: Biological Sciences　292　(2045)　2025/04/30

    Publisher: The Royal Society

    DOI： 10.1098/rspb.2024.3068 　

    eISSN： 1471-2954

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    The gut microbiota significantly influence host health by impacting metabolism, immune function and development. Understanding bacterial behaviours in intestinal folds is crucial owing to their role in biofilm formation, which protects bacteria from immune responses and antibiotics and is associated with colorectal cancer. In this study, we observed the behaviours of Escherichia coli bacteria in the intestinal folds of zebrafish larvae ( Danio rerio ). It is found that E. coli swims in the intestinal folds for extended periods and is confined in a groove on the wall. In order to clarify the mechanism of the confinement, we further performed numerical simulations using a boundary element method. Our simulations demonstrate that bacterial movement in the groove is constrained by hydrodynamic and steric forces. The groove configuration significantly influences bacterial confinement, with bacteria in a deep groove escaping more easily in the presence of background flow. Based on the aggregation rate of E. coli in the intestinal folds of zebrafish larvae, it is indicated that the groove trapping significantly reduces cell flux away from the wall. These findings enhance our understanding of bacterial accumulation and biofilm formation in the gut, with implications for other environments with geometric constraints.

  4. The architecture of sponge choanocyte chambers is well adapted to mechanical pumping functions Peer-reviewed

    Takumi Ogawa, Shuji Koyama, Toshihiro Omori, Kenji Kikuchi, Hélène de Maleprade, Raymond E. Goldstein, Takuji Ishikawa

    Proceedings of the National Academy of Sciences　122　(12)　e2421296122　2025/03/21

    Publisher: Proceedings of the National Academy of Sciences

    DOI： 10.1073/pnas.2421296122 　

    ISSN： 0027-8424

    eISSN： 1091-6490

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    Sponges, the basalmost members of the animal kingdom, exhibit a range of complex architectures in which microfluidic channels connect multitudes of spherical chambers lined with choanocytes, flagellated filter-feeding cells. Choanocyte chambers can possess scores or even hundreds of such cells, which drive complex flows entering through porous walls and exiting into the sponge channels. One of the mysteries of the choanocyte chamber is its spherical shape, as it seems inappropriate for inducing directional transport since many choanocyte flagella beat in opposition to such a flow. Here, we combine direct imaging of choanocyte chambers in living sponges with computational studies of many-flagella models to understand the connection between chamber architecture and directional flow. We find that those flagella that beat against the flow play a key role in raising the pressure inside the choanocyte chamber, with the result that the flow rate and mechanical pumping efficiency reach a maximum at a small outlet opening angle. Comparison between experimental observations and the results of numerical simulations reveal that the chamber diameter, flagellar wave number, and the outlet opening angle of the freshwater sponge Ephydatia muelleri , as well as several other species, are related in a manner that maximizes the mechanical pumping functions. These results indicate the subtle balances at play during morphogenesis of choanocyte chambers, and give insights into the physiology and body design of sponges.

  5. Self-organization of spermatozoa via unsteady elastohydrodynamic interactions enhances their swimming speed and efficiency Peer-reviewed

    Nanami Taketoshi, Toshihiro Omori, Takuji Ishikawa

    Physical Review E　111　(3)　035103　2025/03/18

    Publisher: American Physical Society (APS)

    DOI： 10.1103/physreve.111.035103 　

    ISSN： 2470-0045

    eISSN： 2470-0053

  6. Ciliary fluid dynamics of swimming, feeding, pumping, and sensing Invited Peer-reviewed

    Toshihiro Omori, Takuji Ishikawa

    Physical Review Fluids　in press　2025

  7. Physics of microbial taxis and behaviours in response to various physical stimuli Peer-reviewed

    Takuji Ishikawa, Katsuhiko Sato, Toshihiro Omori, Kenjiro Yoshimura

    Philosophical Transactions of the Royal Society A　383　20240264　2025

  8. Surface-active microrobots can propel through blood faster than inert microrobots Peer-reviewed

    Chenjun Wu, Toshihiro Omori, Takuji Ishikawa

    PNAS Nexus　3　(10)　463　2024/10/01

    Publisher: Oxford University Press (OUP)

    DOI： 10.1093/pnasnexus/pgae463 　

    eISSN： 2752-6542

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    Abstract Microrobots that can move through a network of blood vessels have promising medical applications. Blood contains a high volume fraction of blood cells, so in order for a microrobot to move through the blood, it must propel itself by rearranging the surrounding blood cells. However, swimming form effective for propulsion in blood is unknown. This study shows numerically that a surface-active microrobot, such as a squirmer, is more efficient in moving through blood than an inert microrobot. This is because the surface velocity of the microrobot steers the blood cells laterally, allowing them to propel themselves into the hole they are digging. When the microrobot size is comparable to a red blood cell or when the microrobot operates under a low Capillary number, the puller microrobot swims faster than the pusher microrobot. The trend reverses under considerably smaller microrobot sizes or high Capillary number scenarios. Additionally, the swimming speed is strongly dependent on the hematocrit and magnetic torque used to control the microrobot orientation. A comparative analysis between the squirmer and Janus squirmer models underscores the extensive applicability of the squirmer model. The obtained results provide new insight into the design of microrobots propelled efficiently through blood, paving the way for innovative medical applications.

  9. Drag force on a microrobot propelled through blood Peer-reviewed

    Wu, C., Omori, T., Ishikawa, T.

    Communications Physics　7　(1)　234　2024/07

    DOI： 10.1038/s42005-024-01724-4 　

    ISSN： 2399-3650

  10. Computational Fluid Dynamics of Swimming Microorganisms Invited Peer-reviewed

    Toshihiro Omori, Takuji Ishikawa

    Journal of the Physical Society of Japan　92　(12)　121002　2023/12/15

    Publisher: Physical Society of Japan

    DOI： 10.7566/jpsj.92.121002 　

    ISSN： 0031-9015 1347-4073

  11. Flow-induced diffusion in a packed lattice of squirmers Peer-reviewed

    Yu Kogure, Toshihiro Omori, Takuji Ishikawa

    Journal of Fluid Mechanics　971　A17　2023/09/25

    Publisher: Cambridge University Press ({CUP})

    DOI： 10.1017/jfm.2023.651 　

    ISSN： 0022-1120 1469-7645

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    <jats:p>Mass transport in suspensions of swimming microorganisms is one of the most important factors for the colonisation and growth of microorganisms. Hydrodynamic interactions among swimming microorganisms play an important role in mass transport, especially in highly concentrated suspensions. To elucidate the influence of highly concentrated cells on mass transport, we numerically simulated mass transport in lattices of squirmers that were fixed in space and oriented in the same direction. The effects of different volume fractions, Péclet numbers (<jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" mime-subtype="png" xlink:href="S0022112023006511_inline1.png" /> <jats:tex-math>$Pe$</jats:tex-math> </jats:alternatives> </jats:inline-formula>) and lattice configurations on mass transport were quantified by tracking Lagrangian material points that move with background flow with Brownian diffusivity. Although the flow field became periodic in space and each streamline basically extended in one direction, the motion of tracer particles became diffusive over long durations due to Brownian motion and cross-flows. Flow-induced diffusion was anisotropic and significantly enhanced over Brownian diffusion in the longitudinal direction. We also investigated mass transport in random configurations of squirmers to reproduce more general conditions. Similar enhanced diffusion was also observed in the random configurations, indicating that the flow-induced diffusion appears regardless of the configurations. The present flow-induced diffusion did not follow <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" mime-subtype="png" xlink:href="S0022112023006511_inline2.png" /> <jats:tex-math>$Pe$</jats:tex-math> </jats:alternatives> </jats:inline-formula> dependency of the conventional Taylor dispersion due to the cross-flows. The time and velocity scales were proposed, which enabled us to predict the flow-induced diffusivity from the data of the flow field and Brownian diffusivity without solving the mass conservation equation. The findings reported here improve our understanding of the transport phenomena in packed suspensions of swimming microorganisms.</jats:p>

  12. Biophysical analysis of mechanical signals in immotile cilia of mouse embryonic nodes using advanced microscopic techniques Peer-reviewed

    Takanobu A. Katoh, Toshihiro Omori, Takuji Ishikawa, Yasushi Okada, Hiroshi Hamada

    Bio-protocol　13　(14)　e4715　2023

    Publisher: Bio-Protocol, LLC

    DOI： 10.21769/bioprotoc.4715 　

    ISSN： 2331-8325

  13. Immotile cilia mechanically sense the direction of fluid flow for left-right determination Peer-reviewed

    Takanobu A. Katoh, Toshihiro Omori, Katsutoshi Mizuno, Xiaorei Sai, Katsura Minegishi, Yayoi Ikawa, Hiromi Nishimura, Takeshi Itabashi, Eriko Kajikawa, Sylvain Hiver, Atsuko H. Iwane, Takuji Ishikawa, Yasushi Okada, Takayuki Nishizaka, Hiroshi Hamada

    Science　379　(6627)　66-71　2023/01

    Publisher: American Association for the Advancement of Science (AAAS)

    DOI： 10.1126/science.abq8148 　

    ISSN： 0036-8075

    eISSN： 1095-9203

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    Immotile cilia at the ventral node of mouse embryos are required for sensing leftward fluid flow that breaks left-right symmetry of the body. However, the flow-sensing mechanism has long remained elusive. In this work, we show that immotile cilia at the node undergo asymmetric deformation along the dorsoventral axis in response to the flow. Application of mechanical stimuli to immotile cilia by optical tweezers induced calcium ion transients and degradation of Dand5 messenger RNA (mRNA) in the targeted cells. The Pkd2 channel protein was preferentially localized to the dorsal side of immotile cilia, and calcium ion transients were preferentially induced by mechanical stimuli directed toward the ventral side. Our results uncover the biophysical mechanism by which immotile cilia at the node sense the direction of fluid flow.

  14. Inertial migration of red blood cells under a Newtonian fluid in a circular channel Peer-reviewed

    Takeishi, N., Yamashita, H., Omori, T., Yokoyama, N., Wada, S., Sugihara-Seki, M.

    Journal of Fluid Mechanics　952　A35　2022/11

    DOI： 10.1017/jfm.2022.936 　

    ISSN： 1469-7645 0022-1120

  15. Self-sustaining oscillation of two axonemal microtubules based on a stochastic bonding model between microtubules and dynein Peer-reviewed

    Omori, T., Munakata, S., Ishikawa, T.

    Physical Review E　106　(1)　014402　2022/07/07

    Publisher: American Physical Society (APS)

    DOI： 10.1103/PhysRevE.106.014402 　

    ISSN： 2470-0053 2470-0045

    eISSN： 2470-0053

  16. Soft Microswimmer Powered by Fluid Oscillation Peer-reviewed

    Ishikawa, T., Morita, T., Omori, T.

    Journal of Robotics and Mechatronics　34　(2)　298-300　2022/04/20

    Publisher: Fuji Technology Press Ltd.

    DOI： 10.20965/jrm.2022.p0298 　

    ISSN： 1883-8049 0915-3942

    eISSN： 1883-8049

  17. Rheotaxis and migration of an unsteady microswimmer International-coauthorship Peer-reviewed

    T. Omori, K. Kikuchi, M. Schmitz, M. Pavlovic, C.-H. Chuang, T. Ishikawa

    Journal of Fluid Mechanics　930　A30　2022/01

    Publisher: Cambridge University Press (CUP)

    DOI： 10.1017/jfm.2021.921 　

    ISSN： 0022-1120

    eISSN： 1469-7645

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    Rheotaxis and migration of cells in a flow field have been investigated intensively owing to their importance in biology, physiology and engineering. In this study, first, we report our experiments showing that the microalgae Chlamydomonas can orient against the channel flow and migrate to the channel centre. Second, by performing boundary element simulations, we demonstrate that the mechanism of the observed rheotaxis and migration has a physical origin. Last, using a simple analytical model, we reveal the novel physical mechanisms of rheotaxis and migration, specifically the interplay between cyclic body deformation and cyclic swimming velocity in the channel flow. The discovered mechanism can be as important as phototaxis and gravitaxis, and likely plays a role in the movement of other natural microswimmers and artificial microrobots with non-reciprocal body deformation.

  18. Impact of rheological properties on bacterial streamer formation Peer-reviewed

    Hiroki Kitamura, Toshihiro Omori, Takuji Ishikawa

    Journal of the Royal Society Interface　18　(183)　20210546　2022

    Publisher: The Royal Society

    DOI： 10.1098/rsif.2021.0546 　

    eISSN： 1742-5662

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    Bacterial biofilms, which can be found wherever there is water and a substrate, can cause chronic infections and clogging of industrial flow systems. Despite intensive investigation of the dynamics and rheological properties of biofilms, the impact of their rheological properties on streamer growth remains unknown. We numerically simulated biofilm growth in a pillar-flow and investigated the effects of rheological properties of a filamentous flow-shaped biofilm, called a ‘streamer’, on its formation by varying the viscoelasticity. The flow-field is assumed to be a Stokes flow and is solved by a boundary element method. A Maxwell model is used for extracellular matrix-mediated streamer growth to express the fluidity of streamer formations. Both high elastic modulus and viscosity are needed for streamer formation, and high viscosity promotes streamer growth at low cell concentrations. Our findings are consistent with experimental observations and can explain the relationship between the cell concentrations and viscosity at which streamers form.

  19. Axial and non-axial migration of red blood cells in a microchannel Peer-reviewed

    Naoki Takeishi, Hiroshi Yamashita, Toshihiro Omori, Naoto Yokoyama, Masako Sugihara-Seki

    Micromachines　12　(10)　1162-1162　2022

    Publisher: MDPI AG

    DOI： 10.3390/mi12101162 　

    eISSN： 2072-666X

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    Human red blood cells (RBCs) are subjected to high viscous shear stress, especially during microcirculation, resulting in stable deformed shapes such as parachute or slipper shape. Those unique deformed RBC shapes, accompanied with axial or nonaxial migration, cannot be fully described according to traditional knowledge about lateral movement of deformable spherical particles. Although several experimental and numerical studies have investigated RBC behavior in microchannels with similar diameters as RBCs, the detailed mechanical characteristics of RBC lateral movement—in particular, regarding the relationship between stable deformed shapes, equilibrium radial RBC position, and membrane load—has not yet been fully described. Thus, we numerically investigated the behavior of single RBCs with radii of 4 μm in a circular microchannel with diameters of 15 μm. Flow was assumed to be almost inertialess. The problem was characterized by the capillary number, which is the ratio between fluid viscous force and membrane elastic force. The power (or energy dissipation) associated with membrane deformations was introduced to quantify the state of membrane loads. Simulations were performed with different capillary numbers, viscosity ratios of the internal to external fluids of RBCs, and initial RBC centroid positions. Our numerical results demonstrated that axial or nonaxial migration of RBC depended on the stable deformed RBC shapes, and the equilibrium radial position of the RBC centroid correlated well with energy expenditure associated with membrane deformations.

  20. Cilia and centrosomes: Ultrastructural and mechanical perspectives Invited Peer-reviewed

    Takuji Ishikawa, Hironori Ueno, Toshihiro Omori, Kenji Kikuchi

    Seminars in Cell & Developmental Biology　110　61-69　2021/02

    Publisher: Elsevier BV

    DOI： 10.1016/j.semcdb.2020.03.007 　

    ISSN： 1084-9521

  21. Swimming microorganisms acquire optimal efficiency with multiple cilia Peer-reviewed

    Omori, T., Ito, H., Ishikawa, T.

    Proceedings of the National Academy of Sciences of the United States of America　117　(48)　30201-30207　2020/12

    DOI： 10.1073/pnas.2011146117 　

    ISSN： 1091-6490 0027-8424

  22. Bacterial Biomechanics - From Individual Behaviors to Biofilm and the Gut Flora - International-journal Invited Peer-reviewed

    Takuji Ishikawa, Toshihiro Omori, Kenji Kikuchi

    Applied Physical Letters Bioengineering　4　(4)　041504-041504　2020/10

    DOI： 10.1063/5.0026953 　

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    Bacteria inhabit a variety of locations and play important roles in the environment and health. Our understanding of bacterial biomechanics has improved markedly in the last decade and has revealed that biomechanics play a significant role in microbial biology. The obtained knowledge has enabled investigation of complex phenomena, such as biofilm formation and the dynamics of the gut flora. A bottom-up strategy, i.e., from the cellular to the macroscale, facilitates understanding of macroscopic bacterial phenomena. In this Review, we first cover the biomechanics of individual bacteria in the bulk liquid and on surfaces as the base of complex phenomena. The collective behaviors of bacteria in simple environments are next introduced. We then introduce recent advances in biofilm biomechanics, in which adhesion force and the flow environment play crucial roles. We also review transport phenomena in the intestine and the dynamics of the gut flora, focusing on that in zebrafish. Finally, we provide an overview of the future prospects for the field.

  23. Elasto-hydrodynamic interaction of two swimming spermatozoa Invited Peer-reviewed

    Taketoshi, N., Omori, T., Ishikawa, T.

    Physics of Fluids　32　(10)　101901　2020/09

    DOI： 10.1063/5.0022107 　

    ISSN： 1089-7666 1070-6631

  24. Active droplet driven by a collective motion of enclosed microswimmers Peer-reviewed

    Huang, Z., Omori, T., Ishikawa, T.

    Physical Review E　102　(2)　022603　2020/08

    DOI： 10.1103/PhysRevE.102.022603 　

  25. Hydrodynamic interaction of two deformable torque swimmers Peer-reviewed

    Hitomu Matsui, Toshihiro Omori, Takuji Ishikawa

    Journal of Fluid Mechanics　894　A9　2020/07/10

    Publisher: Cambridge University Press (CUP)

    DOI： 10.1017/jfm.2020.272 　

    ISSN： 0022-1120

    eISSN： 1469-7645

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    <fig position="anchor"> <graphic xmlns:xlink="http://www.w3.org/1999/xlink" mime-subtype="png" mimetype="image" position="float" xlink:href="S0022112020002724_figAb.png" /> </fig>

  26. Rheology of a dilute suspension of deformable microswimmers Invited Peer-reviewed

    Hitomu Matsui, Toshihiro Omori, Takuji Ishikawa

    Physics of Fluids　32　(7)　071902-071902　2020/07/01

    Publisher: AIP Publishing

    DOI： 10.1063/5.0010558 　

    ISSN： 1070-6631

    eISSN： 1089-7666

  27. Shape matters: entrapment of a model ciliate at interfaces Peer-reviewed

    Junichi Manabe, Toshihiro Omori, Takuji Ishikawa

    Journal of Fluid Mechanics　892　A15　2020/06/10

    Publisher: Cambridge University Press (CUP)

    DOI： 10.1017/jfm.2020.160 　

    ISSN： 0022-1120

    eISSN： 1469-7645

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    <fig position="anchor"> <graphic xmlns:xlink="http://www.w3.org/1999/xlink" mime-subtype="png" mimetype="image" position="float" xlink:href="S0022112020001603_figAb.png" /> </fig>

  28. Harnessing random low Reynolds number flow for net migration Peer-reviewed

    Takeru Morita, Toshihiro Omori, Yohei Nakayama, Shoichi Toyabe, Takuji Ishikawa

    Physical Review E　101　(6)　063101　2020/06

    Publisher: American Physical Society (APS)

    DOI： 10.1103/PhysRevE.101.063101 　

    ISSN： 2470-0045

    eISSN： 2470-0053

  29. The shape effect of flagella is more important than bottom-heaviness on passive gravitactic orientation in Chlamydomonas reinhardtii. International-journal Peer-reviewed

    Azusa Kage, Toshihiro Omori, Kenji Kikuchi, Takuji Ishikawa

    Journal of Experimental Biology　223　(5)　jeb205989　2020/03/03

    DOI： 10.1242/jeb.205989 　

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    The way the unicellular, biflagellated, green alga Chlamydomonas orients upward has long been discussed in terms of both mechanics and physiology. In this study, we focus on the mechanics, i.e. the 'passive' mechanisms, of gravitaxis. To rotate the body upwards, cellular asymmetry is critical. Chlamydomonas can be depicted as a nearly spherical cell body with two anterior, symmetric flagella. The present study looks at the question of whether the existence of the flagella significantly affects torque generation in upward reorientation. The 'density asymmetry model' assumes that the cell is spherical and bottom-heavy and that the shape and weight of the flagella are negligible, while the 'shape asymmetry model' considers the shape of the flagella. Both our experimental and simulation results revealed a considerable contribution from shape asymmetry to the upward orientation of Chlamydomonas reinhardtii, which was several times larger than that of density asymmetry. From the experimental results, we also quantified the extent of bottom-heaviness, i.e. the distance between the centers of gravity and the figure when the cell body is assumed to be spherical. Our estimation was approximately 30 nm, only one-third of previous assumptions. These findings indicate the importance of the viscous drag of the flagella to the upward orientation, and thus negative gravitaxis, in Chlamydomonas.

  30. Swimming mediated by ciliary beating: Comparison with a squirmer model Peer-reviewed

    Ito, H., Omori, T., Ishikawa, T.

    Journal of Fluid Mechanics　874　774-796　2019

    DOI： 10.1017/jfm.2019.490 　

  31. Shear-Induced Migration of a Transmembrane Protein within a Vesicle Peer-reviewed

    Nakamura, K., Omori, T., Ishikawa, T.

    Biophysical Journal　116　(8)　1483-1494　2019

    DOI： 10.1016/j.bpj.2019.03.017 　

  32. Swimming of Spermatozoa in a Maxwell Fluid Peer-reviewed

    Toshihiro Omori, Takuji Ishikawa

    Micromachines　10　78-87　2019/01

    DOI： 10.3390/mi10020078 　

  33. Biaxial fluid oscillations can propel a microcapsule swimmer in an arbitrary direction Peer-reviewed

    Morita, T., Omori, T., Ishikawa, T.

    Physical Review E　98　(6)　063102　2018/12

    DOI： 10.1103/PhysRevE.98.063102 　

  34. Passive swimming of a microcapsule in vertical fluid oscillation Peer-reviewed

    Morita, T., Omori, T., Ishikawa, T.

    Physical Review E　98　(2)　023108　2018/08

    DOI： 10.1103/PhysRevE.98.023108 　

  35. Simulation of the nodal flow of mutant embryos with a small number of cilia: Comparison of mechanosensing and vesicle transport hypotheses Peer-reviewed

    Omori, T., Winter, K., Shinohara, K., Hamada, H., Ishikawa, T.

    Royal Society Open Science　5　(8)　180601　2018/08

    DOI： 10.1098/rsos.180601 　

  36. Asymmetry in cilia configuration induces hydrodynamic phase locking Peer-reviewed

    Keiji Okumura, Seiya Nishikawa, Toshihiro Omori, Takuji Ishikawa, Atsuko Takamatsu

    Physical Review E　97　(3)　032411　2018/03/20

    Publisher: American Physical Society

    DOI： 10.1103/PhysRevE.97.032411 　

    ISSN： 2470-0053 2470-0045

  37. Elastohydrodynamic phase-lock in two rotating cilia Peer-reviewed

    Omori, T., Lu, M., Ishikawa, T.

    Journal of Biomechanical Science and Engineering　13　17-00467　2018

    DOI： 10.1299/jbse.17-00467 　

  38. Nodal cilia-driven flow: Development of a computational model of the nodal cilia axoneme Peer-reviewed

    T. Omori, H. Sugai, Y. Imai, T. Ishikawa

    Journal of Biomechanics　61　242-249　2017/08

    DOI： 10.1016/j.jbiomech.2017.07.025 　

    ISSN： 0021-9290

    eISSN： 1873-2380

  39. Cell adhesion during bullet motion in capillaries Peer-reviewed

    Naoki Takeishi, Yohsuke Imai, Shunichi Ishida, Toshihiro Omori, Roger D. Kamm, Takuji Ishikawa

    American Journal of Physiology-Heart and Circulatory Physiology　311　(2)　H395-H403　2016/08

    DOI： 10.1152/ajpheart.00241.2016 　

    ISSN： 0363-6135

    eISSN： 1522-1539

  40. Numerical methods for simulating blood flow at macro, micro, and multi scales Peer-reviewed

    Yohsuke Imai, Toshihiro Omori, Yuji Shimogonya, Takami Yamaguchi, Takuji Ishikawa

    Journal of Biomechanics　49　(11)　2221-2228　2016/07

    DOI： 10.1016/j.jbiomech.2015.11.047 　

    ISSN： 0021-9290

    eISSN： 1873-2380

  41. Upward swimming of a sperm cell in shear flow Peer-reviewed

    Toshihiro Omori, Takuji Ishikawa

    Physical Review E　93　(3)　032402　2016/03

    DOI： 10.1103/PhysRevE.93.032402 　

    ISSN： 2470-0045

    eISSN： 2470-0053

  42. Nutrient uptake in a suspension of squirmers Peer-reviewed

    Takuji Ishikawa, Shunsuke Kajiki, Yohsuke Imai, Toshihiro Omori

    Journal of Fluid Mechanics　789　481-499　2016/02

    DOI： 10.1017/jfm.2015.741 　

    ISSN： 0022-1120

    eISSN： 1469-7645

  43. A numerical model of a red blood cell infected by Plasmodium falciparum malaria: coupling cell mechanics with ligand-receptor interactions Peer-reviewed

    Shunichi Ishida, Yohsuke Imai, Yuki Ichikawa, Stephanie Nix, Daiki Matsunaga, Toshihiro Omori, Takuji Ishikawa

    Science and Technology of Advanced Materials　17　(1)　454-461　2016

    DOI： 10.1080/14686996.2016.1211462 　

    ISSN： 1468-6996

    eISSN： 1878-5514

  44. Deformation of a micro-torque swimmer Peer-reviewed

    Takuji Ishikawa, Tomoyuki Tanaka, Yohsuke Imai, Toshihiro Omori, Daiki Matsunaga

    Proceedings of the Royal Society A: Mathematical Physical and Engineering Sciences　472　(2185)　20150604　2016/01

    DOI： 10.1098/rspa.2015.0604 　

    ISSN： 1364-5021

    eISSN： 1471-2946

  45. Shape matters: Near-field fluid mechanics dominate the collective motions of ellipsoidal squirmers Peer-reviewed

    K. Kyoya, D. Matsunaga, Y. Imai, T. Omori, T. Ishikawa

    Physical Review E　92　(6)　063027　2015/12

    DOI： 10.1103/PhysRevE.92.063027 　

    ISSN： 1539-3755

    eISSN： 1550-2376

  46. Hemodynamics in the Microcirculation and in Microfluidics Invited Peer-reviewed

    Toshihiro Omori, Yohsuke Imai, Kenji Kikuchi, Takuji Ishikawa, Takami Yamaguchi

    Annals of Biomedical Engineering　43　(1)　238-257　2015/01

    DOI： 10.1007/s10439-014-1180-8 　

    ISSN： 0090-6964

    eISSN： 1573-9686

  47. Hydrodynamic interaction between two red blood cells in simple shear flow: its impact on the rheology of a semi-dilute suspension Peer-reviewed

    Toshihiro Omori, Takuji Ishikawa, Yohsuke Imai, Takami Yamaguchi

    Computational Mechanics　54　(4)　933-941　2014/10

    DOI： 10.1007/s00466-014-0997-1 　

    ISSN： 0178-7675

    eISSN： 1432-0924

  48. Numerical analysis of a red blood cell flowing through a thin micropore Peer-reviewed

    Toshihiro Omori, Haruki Hosaka, Yohsuke Imai, Takami Yamaguchi, Takuji Ishikawa

    Physical Review E　89　(1)　013008-1-013008-7　2014/01/13

    DOI： 10.1103/PhysRevE.89.013008 　

    ISSN： 1539-3755 1550-2376

    eISSN： 2470-0053

  49. A full GPU implementation of a numerical method for simulating capsule suspensions Peer-reviewed

    Daiki Matsunaga, Yohsuke Imai, Toshihiro Omori, Takuji Ishikawa, Takami Yamaguchi

    Journal of Biomechanical Science and Engineering　9　(3)　1-16　2014

    Publisher: Japan Society of Mechanical Engineers

    DOI： 10.1299/jbse.14-00039 　

    ISSN： 1880-9863

  50. Shear-induced diffusion of red blood cells in a semi-dilute suspension Peer-reviewed

    T. Omori, T. Ishikawa, Y. Imai, T. Yamaguchi

    Journal of Fluid Mechanics　724　154-174　2013/06/10

    DOI： 10.1017/jfm.2013.159 　

    ISSN： 0022-1120 1469-7645

  51. Membrane tension of red blood cells pairwisely interacting in simple shear flow Peer-reviewed

    Toshihiro Omori, Takuji Ishikawa, Yohsuke Imai, Takami Yamaguchi

    Journal of Biomechanics　46　(3)　548-553　2013/02/01

    DOI： 10.1016/j.jbiomech.2012.09.017 　

    ISSN： 0021-9290 1873-2380

  52. Tension of red blood cell membrane in simple shear flow Peer-reviewed

    T. Omori, T. Ishikawa, D. Barthes-Biesel, A. -V. Salsac, Y. Imai, T. Yamaguchi

    Physical Review E　86　(5)　056321-1-056321-9　2012/11

    DOI： 10.1103/PhysRevE.86.056321 　

    ISSN： 1539-3755

  53. Reorientation of a Nonspherical Capsule in Creeping Shear Flow Peer-reviewed

    Toshihiro Omori, Yohsuke Imai, Takami Yamaguchi, Takuji Ishikawa

    Physical Review Letters　108　(13)　138102-1-138102-5　2012/03

    DOI： 10.1103/PhysRevLett.108.138102 　

    ISSN： 0031-9007

  54. Comparison between spring network models and continuum constitutive laws: Application to the large deformation of a capsule in shear flow Peer-reviewed

    T. Omori, T. Ishikawa, D. Barthes-Biesel, A. -V. Salsac, J. Walter, Y. Imai, T. Yamaguchi

    Physical Review E　83　(4)　41918-1-41918-11　2011/04

    DOI： 10.1103/PhysRevE.83.041918 　

    ISSN： 1539-3755

  55. Immotile cilia of the mouse node sense a fluid flow–induced mechanical force for left-right symmetry breaking

    Takanobu A. Katoh, Toshihiro Omori, Katsutoshi Mizuno, Xiaorei Sai, Katsura Minegishi, Yayoi Ikawa, Hiromi Nishimura, Takeshi Itabashi, Eriko Kajikawa, Sylvain Hiver, Atsuko H. Iwane, Takuji Ishikawa, Yasushi Okada, Takayuki Nishizaka, Hiroshi Hamada

    2022/04/12

    Publisher: Cold Spring Harbor Laboratory

    DOI： 10.1101/2022.04.11.487968 　

    More details Close

    Immotile cilia of crown cells at the node of mouse embryos are required for sensing of a leftward fluid flow1 that gives rise to the breaking of left-right (L-R) symmetry2. The flow-sensing mechanism has long remained elusive, however, with both mechanosensing and chemosensing models having been proposed1, 3–5. Here we show that immotile cilia at the mouse node respond to mechanical force. In the presence of a leftward flow, immotile cilia on the left side of the node bend toward the ventral side whereas those on the right side bend toward the dorsal side. Application of mechanical stimuli to immotile cilia along the dorsoventral axis by optical tweezers induced Ca2+ transients and degradation of Dand5 mRNA—the first known L-R asymmetric molecular events—in the targeted cells. The Pkd2 channel protein was found to be preferentially localized to the dorsal side of immotile cilia on both left and right sides of the node, and the observed induction of Ca2+ transients preferentially by mechanical stimuli directed toward the ventral side could explain the differential response of immotile cilia to the directional flow. Our results thus suggest that immotile cilia at the node sense the direction of fluid flow in a manner dependent on a flow-generated mechanical force.

  56. Flow-induced deformation of a capsule in unbounded stokes flow Peer-reviewed

    Toshihiro Omori, Takuji Ishikawa, Yohsuke Imai, Takami Yamaguchi

    Lecture Notes in Computational Vision and Biomechanics　12　101-117　2014

    Publisher: Kluwer Academic Publishers

    DOI： 10.1007/978-94-007-7769-9_6 　

    ISSN： 2212-9413 2212-9391

Show all ︎Show first 5

Misc. 81

  1. Computational Biomechanics

    Toshihiro Omori

    2023

  2. FLUID-STRUCTURE INTERACTIONS OF NODAL CILIA AXONEME Peer-reviewed

    Toshihiro Omori, Hiroto Sugai, Yohsuke Imai, Takuji Ishikawa

    8th International Conference on Fluid Mechanics (ICFM8)　S10BM0-04　2018/09

  3. Microscale Flow Dynamics of Red Blood Cells in Microchannels: An Experimental and Numerical Analysis Invited Peer-reviewed

    R. Lima, M. Nakamura, T. Omori, T. Ishikawa, S. Wada, T. Yamaguchi

    ADVANCES IN COMPUTATIONAL VISION AND MEDICAL IMAGE PROCESSING: METHODS AND APPLICATIONS　13　203-+　2009

  4. Micro-capsule swimmer controlled by flow oscillations

    T. Morita, T. Omori, T. Ishikawa

    Bulletin of the American Physical Society, DFD 2018　63　(13)　540　2018/11

  5. Hydrodynamics of ciliate swimming revealed by individual ciliary motions

    H. Ito, T. Omori, T. Ishikawa

    Bulletin of the American Physical Society, DFD 2018　63　(13)　341　2018/11

  6. Flow-induced transport of a membrane protein on vesicle surface

    K. Nakamura, T. Omori, T. Ishikawa

    Bulletin of the American Physical Society, DFD 2018　63　(13)　205　2018/11

  7. A NUMERICAL SIMULATION OFSWIMMING SPERMATOZOA Peer-reviewed

    N. Taketoshi, T. Omori, T. Ishikawa

    8th International Conference on Fluid Mechanics (ICFM8)　S10BM0-02　2018/09

  8. Locomotion mechanism of microcapsele using flow oscillation

    Takeru Morita, Toshihiro Omori, Takuji Ishikawa

    The Seven International Symposium on Aero Aqua Bio-mechanisms ISABMEC 2018　44　2018/09

  9. Computational study of the nodal flow with a small number of cilia: comparison of mechanosensing and vesicle transport hypotheses

    Toshihiro Omori, Kyosuke Shinohara, Hiroshi Hamada, Takuji Ishikawa

    8th World Congress of Biomechanics　O0636　2018/07

  10. NUMERICAL SIMULATION OF A SPERM CELL IN SHEAR FLOW NEAR AN INFINITE BOUNDARY WALL

    Toshihiro Omori, Takuji Ishikawa

    Abstracts Book of the 16th International Conference on Biomedical Engineering　34　2016/12

  11. Numerical analysis of cell adhesion in capillary flow

    NAOKI TAKEISHI, YOHSUKE IMAI, SHUNICHI ISHIDA, TOSHIHIRO OMORI, ROGER KAMM, TAKUJI ISHIKAWA

    The 69th Annual Meetin g of The American Physical Society, Bulletin of the American Physical Society, DED 2016　61　72　2016/11

  12. Rheotaxis of a Sperm Cell in Shear Flow Near an Infinite Plane Wall, The 7th International Conference on Computational Methods

    Toshihiro Omori, Takuji Ishikawa

    The 7th International Conference on Computational Methods　MS-043　2016/08

  13. Asymmetry of Arrangement Induces Phase Synchronization in Mouse Node Cilia

    Keiji Okumura, Seiya Nishikawa, Toshihiro Omori, Takuji Ishikawa, Atsuko Takamatsu

    26th IUPAP International conference on Statistical Physics　421　2016/07

  14. Response to the Letter to the Editor "Hemodynamics in the Microcirculation" by A. G. Koutsiaris

    Toshihiro Omori, Yohsuke Imai, Kenji Kikuchi, Takuji Ishikawa, Takami Yamaguchi

    Annals of Biomedical Engineering　44　(4)　1323　2016/04/01

    Publisher: Springer New York LLC

    DOI： 10.1007/s10439-016-1570-1 　

    ISSN： 1573-9686 0090-6964

  15. 1C46 Numerical simulation of a swimming ciliate near a water-air or a water-wall interface

    MANABE Junichi, OMORI Toshihiro, IMAI Yohsuke, ISHIKAWA Takuji

    2016　(28)　"1C46-1"-"1C46-5"　2016/01/09

    Publisher: The Japan Society of Mechanical Engineers

    More details Close

    Swimming behavior of microorganism near an interface is important to understand how to prevent bio-film formation, which can be a cause of medical instrument pollution. Recently, we found that a ciliate can be trapped at a water-air interface, though swims away from a water-wall interface. We conducted numerical simulation of swimming microorganism near an interface from hydrodynamic perspective, to reveal the entrapment mechanism. By mimicking microorganism shape in detail, our microorganism model reproduced entrapment phenomena for the first time in the world. We concluded that shape of a ciliate dominates the entrapment phenomena.

  16. 1C45 A Numerical Simulation of Sperm Cell Locomotion in Shear Flow

    OMORI Toshihiro, ISHIKAWA Takuji

    2016　(28)　"1C45-1"-"1C45-3"　2016/01/09

    Publisher: The Japan Society of Mechanical Engineers

    More details Close

    A sperm cell is a flagellated cell and it can swim in a fluid by beating flagellum. Locomotion of a sperm cell is strongly affected by surrounding fluid flow, and recently rheotaxis of sperm cells was found experimentally. Fluid mechanics then becomes a subject of growing importance in sperm motility. In this study, we numerically investigate sperm cell behavior in shear flow near a plane wall to quantitatively understand how fluid mechanics affects on swimming of sperm cell. Due to the small size of sperm cells, inertia effects of fluid motion can be neglected and we assume Stokes flow around the cell. Flow field is then expressed by boundary integral equation and which is solved by a boundary element method. As a result, the sperm cell shows reorient to upstream and keeps on swimming against the fluid flow. This result suggests that fluid mechanics plays a key role in navigation of sperm cells towards the ovum, which is located upstream in the oviduct.

  17. 195 Numerical simulation of a sperm cell swimming in a viscoelastic fluid

    SHIMOMURA Eisaku, OMORI Toshihiro, IMAI Yhosuke, ISHIKAWA Takuji

    2016　(51)　187-188　2016

    Publisher: The Japan Society of Mechanical Engineers

  18. Phase locking due to asymmetric arrangement in a model of three identical cilia

    Okumura K, Nishikawa S, Omori T, Ishikawa T, Takamatsu A

    Meeting Abstracts of the Physical Society of Japan　71　(0)　2782-2782　2016

    Publisher: The Physical Society of Japan

    DOI： 10.11316/jpsgaiyo.71.2.0_2782 　

    More details Close

    &lt;p&gt;マウス胚のノード繊毛は時計回りの回転運動をする。少数繊毛系等でこの回転運動が位相同期することが観測されている。我々は繊毛間の流体的な相互作用を境界要素法により数値的に求め、振動子モデルとして繊毛間の位相差を位相縮約法により解析した。本発表では同質な繊毛パラメータの場合、2繊毛系では位相同期が起こらない一方、3繊毛系では繊毛の空間的な配置の非対称性により位相同期が起こることを報告する。&lt;/p&gt;

  19. Deformable micro torque swimmer

    TAKUJI ISHIKAWA, TOMOYUKI TANAKA, TOSHIHIRO OMORI, YOHSUKE IMAI

    68th Annual Meeting of the Division of Fluid Dynamics, Bulletin of the American Physical Society, DFD 2015　60　72　2015/11/01

  20. B212 A numerical simulation of cytoskeletal dynamics

    SAITO Fumiyasu, IMAI Yohsuke, ISHIDA Shunichi, OMORI Toshihiro, ISHIKAWA Takuji

    Proceedings of the ... JSME Conference on Frontiers in Bioengineering　2015　(26)　123-124　2015/10/01

    Publisher: The Japan Society of Mechanical Engineers

    ISSN： 1348-2939

  21. PS8-15 Mechanics of nodal cilia in early mouse embryo(PS8: Poster Short Presentation VIII,Poster Session)

    Omori Toshihiro, Sugai Hiroto, Imai Yohsuke, Ishikawa Takuji

    Proceedings of the ... Asian Pacific Conference on Biomechanics : emerging science and technology in biomechanics　2015　(8)　366-366　2015/09/16

    Publisher: The Japan Society of Mechanical Engineers

  22. PS3-7 DEVELOPMENT OF A NUMERICAL MODEL OF CYTOSKELETON DYNAMICS(PS3: Poster Short Presentation III,Poster Session)

    Saito Fumiyasu, Imai Yohsuke, Ishida Shunichi, Omori Toshihiro, Ishikawa Takuji

    Proceedings of the ... Asian Pacific Conference on Biomechanics : emerging science and technology in biomechanics　2015　(8)　268-268　2015/09/16

    Publisher: The Japan Society of Mechanical Engineers

  23. PS1-10 Swimming behavior of a model ciliate near a fluid-air or a fluid-solid interface(PS1: Poster Short Presentation I,Poster Session)

    Manabe Junichi, Omori Toshihiro, Imai Yohsuke, Ishikawa Takuji

    Proceedings of the ... Asian Pacific Conference on Biomechanics : emerging science and technology in biomechanics　2015　(8)　231-231　2015/09/16

    Publisher: The Japan Society of Mechanical Engineers

  24. Intergrated Computational Biomechanics of the Flow Phenomena in the Living Body

    Takami Yamaguchi, Yosuke Imai, Toshihiro Omori, Kenji Kikuchi, Takuji Ishikawa

    Computational Fluid Dynamics (CFD) in Medicine and Biology II　2015/09/01

  25. Mechanics of Nodal Cilia in Early Mouse Embryo

    Toshihiro Omori, Hiroto Sugai, Yohsuke Imai, Takuji Ishikawa

    The 8th Asian-Pacific Conference on Biomechanics　PS8-15　2015/09/01

  26. Development of a Numerical Model of Cytoskeleton Dynamics

    Fumiyasu Saito, Yohsuke Imai, Shunichi Ishida, Toshihiro Omori, Takuji Ishikawa

    The 8th Asian-Pacific Conference on Biomechanics　PS3-7　2015/09/01

  27. A Numerical Simulation of Cytoadhesion and Rosette Formation of Red Blood Cells Infected by Malaria

    Yohsuke Imai, Yuki Ichikawa, Shunichi Isida, Daiki Matsunaga, Stephanie Nix, Toshihiro Omori, Takami Yamaguchi, Takuji Ishikawa

    The 8th Asian-Pacific Conference on Biomechanics　OS2-2　2015/09/01

  28. Simulations of a swimming microorganism near an fluid-air or an fluid-solid interface

    Junichi Manabe, Toshihiro Omori, Yohsuke Imai, Takuji Ishikawa

    Computational Fluid Dynamics (CFD) in Medicine and Biology II　2015/09/01

  29. Cellular Scale Physiological Flow: Active Swimming Sperm Cells and Passive Flowing Red Blood Cells

    Toshihiro Omori, Takuji Ishikawa, Yohsuke Imai, Takami Yamaguchi

    13th U.S. National Congress on Computational Mechanics　2015/07/01

  30. Viscosity Reduction in Bimodal Suspensions of Two Types of Capsules

    Yohsuke Imai, Hiroki Ito, Daiki Matsunaga, Toshihiro Omori, Takami Yamaguchi, Takuji Ishikawa

    13th U.S. National Congress on Computational Mechanics　2015/07/01

  31. A Computational Study Of Red Blood Cells In Stokes Flow: From Single Cellular Mechanics To Suspension Rheology

    Toshihiro Omori, Yohsuke Imai, Takami Yamaguchi, Takuji Ishikawa

    SB3C2015　256　2015/06/01

  32. Rheology of A Red Blood Cell Suspension Computing with A Boundary Element-Finite Element Coupled Method

    Toshihiro Omori, Yohsuke Imai, Takuji Ishikawa

    The 18th International Conference on Finite Elements in Flow Problems FEF2015　23　2015/03/01

  33. 1A16 Numerical Simulation of the Nodal Ciliary Motion Driven by the Dynein Motor Protein

    SUGAI Hiroto, Omori Toshihiro, IMAI Yohsuke, ISHIKAWA Takuji

    2015　(27)　13-14　2015/01/08

    Publisher: The Japan Society of Mechanical Engineers

  34. 1A12 Behavior of tracer particles in capsule suspensions : the effect of size of tracer particles

    ITO Hiroki, IMAI Yohsuke, MATSUNAGA Daiki, Omori Toshihiro, YAMAGUCHI Takami, ISHIKAWA Takuji

    2015　(27)　5-6　2015/01/08

    Publisher: The Japan Society of Mechanical Engineers

  35. 1D35 Rheology of a red blood cell suspension in a simple shear flow

    OMORI Toshihiro, ISHIKAWA Takuji, IMAI Yohsuke, YAMAGUCHI Takami

    2015　(27)　165-166　2015/01/08

    Publisher: The Japan Society of Mechanical Engineers

  36. 22pBL-8 Synchronized oscillation in a model of three nodal cilia with hydrodynamic interaction

    Okumura K, Nishikawa S, Omori T, Ishikawa T, Takamatsu A

    Meeting Abstracts of the Physical Society of Japan　70　(0)　3030-3030　2015

    Publisher: The Physical Society of Japan

    DOI： 10.11316/jpsgaiyo.70.1.0_3030 　

    ISSN： 2189-079X

  37. 16pCX-1 Parameter dependence on synchronization in a model of two nodal cilia

    Okumura K, Nishikawa S, Omori T, Ishikawa T, Takamatsu A

    Meeting Abstracts of the Physical Society of Japan　70　(0)　2595-2595　2015

    Publisher: The Physical Society of Japan

    DOI： 10.11316/jpsgaiyo.70.2.0_2595 　

    ISSN： 2189-079X

  38. Swimming behavior of a model microorganism at a fluid-air interface

    Junichi Manabe, Kohei Kyoya, Toshihiro Omori, Yohsuke Imai, Takuji Ishikawa

    The Sixth International Symposium on Aero Aqua Bio-mechanisms　37　2014/11/01

  39. A112 Numerical Simulation of the Ciliary Motion Driven by the Motor Protein

    SUGAI Hiroto, OMORI Toshihiro, IMAI Yohsuke, ISHIKAWA Takuji

    Proceedings of the ... JSME Conference on Frontiers in Bioengineering　2014　(25)　21-22　2014/10/02

    Publisher: The Japan Society of Mechanical Engineers

    ISSN： 1348-2939

  40. A111 A numerical simulation of a microorganism behavior near an interface

    Manabe Junichi, Kyouya Kouhei, Omori Toshihiro, Imai Yohsuke, Ishikawa Takuji

    Proceedings of the ... JSME Conference on Frontiers in Bioengineering　2014　(25)　19-20　2014/10/02

    Publisher: The Japan Society of Mechanical Engineers

    ISSN： 1348-2939

  41. Rheological analysis of capsule suspensions containing different size capsules

    Hiroki Ito, Yohsuke Imai, Daiki Matsunaga, Toshihiro Omori, Takami Yamaguchi, Takuji Ishikawa

    11th World Congress on Computational Mechanics　303　2014/07/10

  42. Numerical Analysis of Capsule Suspensions Containing Two Different siza Capsules

    Hiroki Ito, Yohsuke Imai, Daiki Matsunaga, Toshihiro Omori, Takami Yamaguchi, Takuji Ishikawa

    Dyna Caps 2014　2014/07/10

  43. Collective swimming of ellipoidal squimers

    Takuji Ishikawa, Kohei Kyoya, Daiki Matsunaga, Yohsuke Imai, Toshihiro Omori

    Dyna Caps 2014　2014/07/10

  44. Development of a numerical model for analysis of ciliary motions

    H. Sugai, T. Omori, Y. Imai, T. Ishikawa

    7th WORLD CONGRESS OF BIOMECHANICS　2014/07/10

  45. Development of an Intracellular Structure Model for Ciliary Motion Analysis

    Hiroto Sugai, Toshihiro Omori, Yohsuke Imai, Takami Yamaguchi, Takuji Ishikawa

    Internationnal Symposium on Integrated Nanobiomechanics　17-18　2014/07/05

  46. Nutrient Uptake in a Suspension of Model Microorganisms

    Takuji Ishikawa, Shunsuke Kajiki, Yohsuke Imai, Toshihiro Omori

    Internationnal Symposium on Integrated Nanobiomechanics　15-16　2014/07/05

  47. Rheology of a Red Blood Cell Suspension from Dilute to Semi-dilute Regime

    Toshihiro Omori, Yohsuke Imai, Takami Imai, Takuji Ishikawa

    Internationnal Symposium on Integrated Nanobiomechanics　11-12　2014/07/05

  48. Nutrient uptake in a suspension of model microorganisms

    Takuji Ishikawa, Shunsuke Kajiki, Yohsuke Imai, Toshihiro Omori

    COMPSAFE　347-348　2014/04/02

  49. 2E15 Numerical analysis of a red blood cell flowing through a micro flow channel

    OMORI Toshihiro, ISHIKAWA Takuji, IMAI Yohsuke, YAMAGUCHI Takami

    2014　(26)　439-440　2014/01/10

    Publisher: The Japan Society of Mechanical Engineers

  50. 167 気液界面における微生物の遊泳シミュレーション

    眞鍋 隼一, 京谷 浩平, 今井 陽介, 大森 俊宏, 石川 拓司

    講演論文集　2014　(49)　131-132　2014

    Publisher: 一般社団法人日本機械学会

  51. Effect of Aeration on the Bioconvection Pattern in a Microalgae Suspension

    Y. Nonaka, H. Ueno, K. Numayama, T. Omori, Y. Imai, T. Yamaguchi, T. Ishikawa

    APCB2013 Proceedings　S12-002　2013/08/30

  52. Integrated Biomechanics for Physiological Flow Problems

    T. Yamaguchi, Y. Imai, T. Omori, H. Ueno, K. Numayama-Tsuruta, T. Ishikawa

    APCB2013 The7thAsian Pacific Conference on Biomechanics　ILS4-009　2013/08/29

  53. 2E02 Analysis of Red Blood Cell Behavior in a Narrow Tube

    HOSAKA Haruki, OMORI Toshihiro, IMAI Yohsuke, ISHIKAWA Takuji, YAMAGUCHI Takami

    2013　(25)　387-388　2013/01/08

    Publisher: The Japan Society of Mechanical Engineers

  54. 3E15 Measurement of ciliary flow generated on the surface of tracheal lumen

    KIYOTA Koki, UENO Hironori, ISHIKAWA Takuji, NUMAYAMA Keiko, IMAI Yohsuke, OMORI Toshihiro, YAMAGUCHI Takami

    The Proceedings of the Bioengineering Conference Annual Meeting of BED/JSME　2013　(0)　609-610　2013

    Publisher: The Japan Society of Mechanical Engineers

    DOI： 10.1299/jsmebio.2013.25.609 　

  55. J027013 Effect of aeration on the bio-convection of micro algae cells

    NONAKA Yuki, UENO Hironori, NUMAYAMA Keiko, OMORI Toshihiro, IMAI Yohsuke, YAMAGUCHI Takami, ISHIKAWA Takuji

    The Proceedings of Mechanical Engineering Congress, Japan　2013　(0)　_J027013-1-_J027013-4　2013

    Publisher: The Japan Society of Mechanical Engineers

    DOI： 10.1299/jsmemecj.2013._J027013-1 　

    More details Close

    Bioconvection patterns are often observed in microalgae suspensions of randomly, but on average upwardly, swimming microalgae which are little denser than water. When we culture microalgae in the laboratory, we usually add aeration for mixing the culture fluid and supplying oxygen and carbon dioxide. However, the effect of aeration on the bioconvection pattern and the transport phenomena in the suspension is unclear. In this study, we investigated bioconvection pattern in a suspension of Chlamydomonas reinhardtii under the condition with aeration. Bioconvection pattern in a cylindrical container was visualized by red illumination, and white light for phototaxis could be added from above. Small bubbles were injected by a needle connected to a syringe. Observation of bioconvection patterns of microalgae suspension with aeration showed three kinds of flow patterns depending on the bubble flow rate. When there was no bubble flow, conventional bioconvection was dominant. When flow rate was low, observed pattern in the cylindrical container was split into two flow regions, where the bioconvection and the bubble flow were dominant respectively. When flow rate was high, bubble flow became dominant and no clear bioconvection was observed. Such changes in the bioconvection pattern have not been reported before. These findings are important to understand the transport phenomena in algae suspensions in engineering settings.

  56. C107 Bioconvection of micro algae cells under an aeration condition

    NONAKA Yuki, UENO Hirinori, NUMAYAMA Keiko, OMORI Toshihiro, IMAI Yosuke, YAMAGUCHI Takami, ISHIKAWA Takuji

    The Proceedings of the JSME Conference on Frontiers in Bioengineering　2013　(0)　45-46　2013

    Publisher: The Japan Society of Mechanical Engineers

    DOI： 10.1299/jsmebiofro.2013.24.45 　

    ISSN： 1348-2939

  57. 103 Aggregation structure of algae in forced circulation bubbly flow

    NONAKA Yuki, UENO Hironori, NUMAYAMA-TSURUTA Keiko, OMORI Toshihiro, IMAI Yosuke, YAMAGUCHI Takami, ISHIKAWA Takuji

    The Proceedings of Conference of Tohoku Branch　2013　(0)　10-11　2013

    Publisher: The Japan Society of Mechanical Engineers

    DOI： 10.1299/jsmeth.2013.48.10 　

  58. 計算生体力学シミュレーションによるミクロからマクロスケールの生体機能の解析

    山口 隆美, 今井 陽介, 水野 文雄, 大森 俊宏, 上野 裕則, 沼山 恵子, 石川 拓司

    バイオメカニズム学術講演会予稿集　33回　33-34　2012/12

    Publisher: バイオメカニズム学会

  59. Off-plane motion of a non-spherical capsule in simple shear flow

    T. Omori, T. Ishikawa, Y. Imai, T. Yamaguchi

    Bulletin of the American Physical Society 65th Annual Meeting of the APS Division of Fluid Dynamics　331-331　2012/11

  60. Measurement of ciliary flow generated on the surface of tracheal lumen

    K. Kiyota, H. Ueno, T. Ishikawa, K. Numayama-Tsuruta, Y. Imai, T. Omori, T. Yamaguchi

    Bulletin of the American Physical Society 65th Annual Meeting of the APS Division of Fluid Dynamics　334-334　2012/11

  61. Analysis of red blood cell behavior in a narrow tube

    H. Hosaka, T. Omori, Y. Imai, T. Yamaguchi, T. Ishikawa

    Bulletin of the American Physical Society 65th Annual Meeting of the APS Division of Fluid Dynamics　330-330　2012/11

  62. Development of a GPU-Implemented BEM solver for biological cell suspensions

    Y. Imai, D. Matsunaga, K. Kyoya, T. Omori, T. Ishikawa, T. Yamaguchi

    International Computational Mechanics Symposium 2012　USB Memory　2012/10

  63. ストークス流れ中の非球形カプセルの配向現象

    石川拓司, 大森俊宏, 今井陽介, 山口隆美

    京都大学数理解析研究所講究録　1808　(1808)　121-126　2012/09/01

    Publisher: 京都大学

    ISSN： 1880-2818

  64. Numerical Analysis of a Red Blood Cells in Simple Shear Flow

    17　4p　2012/05

    Publisher: 日本計算工学会

  65. Computational biomechanics of physiological flow

    T. Yamaguchi, T. Ishikawa, Y. Imai, H. Ueno, K. Numayama-Tsuruta, T. Omori

    Biological Flow: A Conference to Celebrate the 70th Birthday of Timothy J. Padley FRS　38　2012/03/20

  66. 109 Analysis of Red Blood Ce11 Deformation in Flow Field Using a Boundary Element Method

    Hosaka Haruki, Ishikawa Takuji, Omori Toshihiro, Imai Yohsuke, Yamaguchi Takami

    2012　(47)　24-25　2012/03/13

    Publisher: The Japan Society of Mechanical Engineers

  67. Rheology of a dilute suspention of red blood cells in simple shear flow

    T. Omori, T. Ishikawa, Y. Imai, T. Yamaguchi

    18th International Symposium of Tohoku University Global COE Program, Global Nano-Biomedical Engineering Education and Research Network Centre, Nano-Biomedical Engineering in the East Asian-Pacific Rim Region　153-154　2012/03

  68. Multi-GPU computing of capsule flow using boundary integral method

    D. Matsunaga, Y. Imai, T. Omori, T. Ishikawa, T. Yamaguchi

    5th East Asian Pacific Student Workshop on Nano-Biomedical Engineering　72-73　2011/12

  69. B112 Development of GPU computing method for capsule suspension

    MATSUNAGA Daiki, IMAI Yohsuke, OMORI Toshihiro, MIKI Takahito, ISHIKAWA Takuji, YAMAGUCHI Takami

    Proceedings of the ... JSME Conference on Frontiers in Bioengineering　2011　(22)　61-62　2011/10/06

    Publisher: The Japan Society of Mechanical Engineers

    ISSN： 1348-2939

  70. High performance GPU computing of capsule flow using boundary integral method

    D.Matsunaga, Y.Imai, T.Omori, T.Miki, T.Ishikawa, T.Yamaguchi

    Proc. Japan-Portugal Nano-BME Symp　19-22　2011/06

  71. Capsule flow analysis using GPU computation

    D. Matsunaga, Y. Imai, T. Omori, T. Miki, T. Ishikawa, T. Yamaguchi

    Microscale Modeling in Biomechanics and Mechanobiology Program and Abstract　2011/05

  72. Effect of Membrane Modeling on the Capsule Deformation: Comparison between a Spring Network and Continuum Models

    T.Omori, T.Ishikawa, D.Barthes-Biesel, A.-V.Salsac, Y.Imai, T.Yamaguchi

    6th World Congress of Biomechanics Abstracts　470　2010/08

  73. Impact of membrane modeling in analysing deformation of a capsule:comparison between a spring network model and constitutive laws Peer-reviewed

    T.Omori, T.Ishikawa, D.Barthes-biesel, A.V.Salsac, Y.Imai, T.Yamaguchi

    Proc. 4th ECCM　No. 781　2010/05

  74. Impact of membrane modeling on the deformation analysis of a capsule

    T.Omori, T.Ishikawa, D.Barthes-Biesel, A.V.Salsac, Y.Imai, T.Yamaguchi

    3rd East Asian Pacific Student Workshop on Nano-Biomedical Engineering　122-123　2009/12

  75. Modeling of the membrane bending rigidity for calculating red blood cell deformation

    T. Omori, T. Ishikawa, D. Birthes-Biesel, Y. Imai, T. Yamaguchi

    15th Int. Conf. Finite Elements in Flow Problems (FEF09) Abstracts　41　2009/04

  76. Effect of the membrane bending stiffness on the deformation of a red blood cell

    T. Omori, T. Ishikawa, D. Birthes-Biesel, Y. Imai, T. Yamaguchi

    Proc. AP Biomech　196-197　2009/04

  77. Behavior of a red blood cell in a simple shear flow simulated by a boundary element method

    T. Omori, T. Ishikawa, D. Barthes-Biesel, Y. Imai, T. Yamaguchi

    GPBE/NUS-Tohoku Graduate Student Conf. Bioeng., Program & Abstract　99-100　2008/12/01

  78. B203 Behavior of a Red Blood Cell in a Simple Shear Flow Simulated by a Boundary Element Method

    OMORI Toshihiro, ISHIKAWA Takuji, BARTHES-BIESEL Dominique, IMAI Yohsuke, YAMAGUCHI Takami

    Proceedings of the ... JSME Conference on Frontiers in Bioengineering　2008　(19)　47-48　2008/09/22

    Publisher: The Japan Society of Mechanical Engineers

    ISSN： 1348-2939

  79. Behavior of a red blood cell in a simple shear flow simulated by a boundary element method

    T. Omori, T. Ishikawa, D. Barthes-Biesel, Y. Imai, T. Yamaguchi

    Book of Abstracts BIOENGINEERING 08　135-135　2008/09

  80. Proposal of mesoscopic analysis method of blood rheology

    M. Nakamura, T. Omori, T. Yamaguchi, S. Wada

    Proceedings of the Third Asian Pacific Conference on Biomechanics (To appear in Journal of Biomechanical Science and Engineering)　2　(07-207)　228-228　2007/11/08

  81. Computational Analysis of a Non-Newtonian Behavior of Blood Flow by an Interactive Calculation of Micro- and Micro- Scale Blood Dynamics

    M. Nakamura, T. Omori, T. Yamaguchi, S. Wada

    The 9th International Symposium on Future Medical Engineering based on Bio-nanotechnology jointly organized with The 19th Bioengineering Conference, 2006 Annual Meeting of BED/JSME　44-45　2007/01

Show all ︎Show first 5

Books and Other Publications 3

  1. Integrated nano-Biomechanics,

    T. Omori

    Elsevier　2018/06

  2. Visualization and simulations of complex flows in biomedical engineering

    T. Omori, T. Ishikawa, Y. Imai, T. Yamaguchi

    Springer　2014

  3. Advances in Computational Vision and Medical Image Processing

    R. Lima, M. Nakamura, T. Omori, T. Ishikawa, S. Wada, T. Yamaguchi

    Springer　2009

Presentations 114

  1. Numerical Simulation of collective swimming of sperm Invited

    Toshihiro Omori

    2022/09/11

  2. Ciliates achieve optimal swimming efficiency through hydrodynamic interaction of cilia Invited

    Toshihiro Omori

    9th World Congress of Biomechanics　2022/07/11

  3. 繊毛間流体相互作用と遊泳微生物の形態 Invited

    大森俊宏

    第34回バイオエンジニアリング講演会　2022/06/25

  4. Elasto-hydrodynamic interaction of swimming spermatozoa Invited

    Toshihiro Omori

    Biofluid Mechanics of Reproduction　2021/07/29

  5. Multiciliation maximises the swimming efficiency of microorganisms Invited

    Toshihiro Omori

    2021/02/24

  6. 繊毛運動の流体構造連成 Invited

    大森俊宏

    ソフトバイオ研究会2018　2018/11/21

  7. Numemrical simulation of swimming ciliates: Computational fluid dynamic for low Reynolds number regime Invited

    T. Omori, H. Ito, T. Ishikawa

    2018/10/19

  8. FLUID-STRUCTURE INTERACTIONS OF NODAL CILIA AXONEME

    Toshihiro Omori, Hiroto Sugai, Yohsuke Imai, Takuji Ishikawa

    8th International Conference on Fluid Mechanics (ICFM8)　2018/09

  9. Rheotaxis of a sperm cell in shear flow near an infinite plane wall International-presentation Invited

    T. Omori, T. Ishikawa

    The 7th International Conference on Computational Methods　2016/08

  10. A boundary element method for cellular scale physiological flow problems International-presentation Invited

    T. Omori, Y. Imai, T. Yamaguchi, T. Ishikawa

    The 3rd International Workshops on Advances in Computational Mechanics,　2015/10

  11. Intergrated Computational Biomechanics of the Flow Phenomena in the Living Body International-presentation Invited

    T. Yamaguchi, Y. Imai, T. Omori, K. Kikuchi, T. Ishikawa

    Computational Fluid Dynamics in Medicine and Biology II　2015/08

  12. Swimming of a spermatozoon in shear flow near non-slip boundary International-presentation Invited

    T. Omori, T. Ishikawa

    Computational Fluid Dynamics in Medicine and Biology II　2015/08

  13. Viscosity Reduction in Bimodal Suspensions of Two Types of Capsules International-presentation Invited

    Y. Imai, H. Ito, D. Matsunaga, T. Omori, T. Yamaguchi, T. Ishikawa

    13th US National Congress on Computational Mechanics　2015/07

  14. Cellular scale physiological flow: active swimming sperm cells and passive flowing red blood cells International-presentation Invited

    T. Omori, T. Ishikawa, Y. Imai, T. Yamaguchi

    13th US National Congress on Computational Mechanics　2015/07

  15. Rheology of a red blood cell suspension computing with a boundary element-finite element coupled method International-presentation Invited

    T. Omori, Y. Imai, T. Ishikawa

    8th International Conference on Finite Elements in Flow Problems　2015/03

  16. Collective motions of ellipsoidal squirmers in a dense suspension International-presentation Invited

    T. Ishikawa, K. Kyoya, D. Matsunaga, Y. Imai, T. Omori

    7th World Congress of Biomechanics　2014/07

  17. A boundary element finite element coupling method for capsule dynamics Invited

    Toshihiro Omori

    2014/07

  18. Rheology of a red blood cell suspension in a simple shear flow International-presentation Invited

    T. Omori, Y. Imai, D. Matsunaga, T. Yamaguchi, T. Ishikawa

    7th World Congress of Biomechanics　2014/07

  19. Integrated Biomechanics for Physiological Problems International-presentation Invited

    T. Yamaguchi, Y. Imai, T. Omori, H. Ueno, K. Numayama-Tsuruta, T. Ishikawa

    The 7th Asian Pacific Conference on Biomechanics　2013/08

  20. Microscale Flow Dynamics of Red Blood Cells in Microchannels: An Experimental and Numerical Analysis Invited

    R. Lima, M. Nakamura, T. Omori, T. Ishikawa, S. Wada, T. Yamaguchi

    ADVANCES IN COMPUTATIONAL VISION AND MEDICAL IMAGE PROCESSING: METHODS AND APPLICATIONS　2009

    More details Close

    The blood flow dynamics in microcirculation depends strongly on the motion, deformation and interaction of red blood cells (RBCs) within the microvessel. We present confocal micro-PTV measurements on the motion of individual RBCs through a circular polydimethysiloxane (PDMS) microchannel. The RBC radial displacement and dispersion calculated from these measurements show that the RBC paths are strongly dependent on the both Hct and plasma layer. In order to obtain more detailed information of the non-Newtonian property of blood a novel computational scheme is also described. The simulated flow dynamics were in good agreement with the Casson flow model and in vivo observations. In the near future by comparing both results we hope to clarify a variety of complex phenomena occurring at the microscale level.

  21. Collective Swimming of Sperm Emerging from Unsteady Hydrodynamic Interactions

    T. Omori

    6th Japan-Switzerland Workshop on Biomechanics　2023/09/01

  22. Mass transport in an aggregation of swimming microorganisms

    Yu Kogure, Toshihiro Omori, Takuji Ishikawa

    11th Asian-Pacific Conference on Biomechanics　2021/12/05

  23. Dynamics of a swimming microorganism suspension

    Kiyoto Kubo, Toshihiro Omori, Takuji Ishikawa

    11th Asian-Pacific Conference on Biomechanics　2021/12/03

  24. Numerical simulation of the sponge’s choanocyte chamber

    Takumi Ogawa, Toshihiro Omori, Takuji Ishikawa

    11th Asian-Pacific Conference on Biomechanics　2021/12/03

  25. Numerical analysis of collective swimming of sperm in three dimension

    Nanami Taketoshi, Toshihiro Omori, Takuji Ishikawa

    11th Asian-Pacific Conference on Biomechanics　2021/12/03

  26. Effect of pairwise interaction of swimming sperm cells

    Nanami Taketoshi, Toshihiro Omori, Takuji Ishikawa

    14th World Congress on Computational Mechanics　2021/01

  27. Harnessing low Reynolds number flow for net migration: locomotion of a deformable microcapsule by random fluid forces

    T. Ishikawa, T. Morita, T. Omori

    Annual Meeting of the Division of Fluid Dynamics　2019/11

  28. Collision of two deformable torque swimmers

    H. Matsui, T. Omori, T. Ishikawa

    Annual Meeting of the Division of Fluid Dynamics　2019/11

  29. Numerical simulation of a droplet propelled by collective swimming of microorganism

    Z. Huang, T. Omori, T. Ishikawa

    AP-Biomech 2019　2019/11

  30. Micro-capsule swimmer controlled by flow oscillations

    T. Morita, T. Omori, T. Ishikawa

    Bulletin of the American Physical Society, DFD 2018　2018/11

  31. Flow-induced transport of a membrane protein on vesicle surface International-presentation

    K. Nakamura, T. Omori, T. Ishikawa

    71st Annual Meeting of the Division of Fluid Dynamics　2018/11

  32. Hydrodynamics of ciliate swimming revealed by individual ciliary motions International-presentation

    H. Ito, T. Omori, T. Ishikawa

    71st Annual Meeting of the Division of Fluid Dynamics　2018/11

  33. Micro-capsule swimmer controlled by flow oscillation International-presentation

    T. Morita, T. Omori, T. Ishikawa

    71st Annual Meeting of the Division of Fluid Dynamics　2018/11

  34. Locomotion mechanism of microcapsele using flow oscillation

    Takeru Morita, Toshihiro Omori, Takuji Ishikawa

    The Seven International Symposium on Aero Aqua Bio-mechanisms ISABMEC 2018　2018/09

  35. A NUMERICAL SIMULATION OFSWIMMING SPERMATOZOA

    N. Taketoshi, T. Omori, T. Ishikawa

    8th International Conference on Fluid Mechanics (ICFM8)　2018/09

  36. A numerical Simulation of Swimming Spermatozoa International-presentation

    N. Taketoshi, T. Omori, T. Ishikawa

    The 8th International Conference of Fluid Mechanics　2018/09

  37. Fluid-structure interactions of nodal cilia axoneme International-presentation

    T. Omori, H. Sugai, Y. Imai, T. Ishikawa

    The 8th International Conference of Fluid Mechanics　2018/09

  38. Locomotion mechanism of microcapsule using flow oscillation International-presentation

    T. Morita, T. Omori, T. Ishikawa

    The seventh international symposium on aero aqua bio-mechanisms　2018/08

  39. Computational study of the nodal flow with a small number of cilia: comparison of mechanosensing and vesicle transport hypotheses International-presentation

    T Omori, K. Shinohara, H. Hamada, T. Ishikawa

    The 8th World Congress of Biomechanics　2018/07

  40. A BOUNDARY ELEMENT METHOD FOR CELLULAR SCALE PHYSIOLOGICAL FLOW PROBLEMS: PASSIVE MOTIONS OF RED BLOOD CELLS AND ACTIVE MOTIONS OF CILIA AND FLAGELLA Invited

    Toshihiro Omori, Yohsuke Imai, Takami Yamaguchi, Takuji Ishikawa

    The 26th Congress of the International Society of Biomechanics (ISB 2017)　2017/07

    More details Close

    Yamaguchi Medal 受賞講演

  41. UPSTREAM SWIMMING OF A SPERM CELL IN SHEAR FLOW

    Toshihiro Omori, Takuji Ishikawa

    The 26th Congress of the International Society of Biomechanics (ISB 2017)　2017/07

  42. DEVELOPMENT OF A BIOMECHANICAL MODEL OF CELL BEHAVIOR SUBJECTED TO CYCLIC STRETCH

    Fumiyasu Saito, Yohsuke Imai, Shunichi Ishida, Toshihiro Omori, Takuji Ishikawa

    Abstracts Book of the 16th International Conference on Biomedical Engineering　2016/12

  43. Numerical simulation of a sperm cell in shear flow near an infinite boundary wall International-presentation

    T. Omori, T. Ishikawa

    The 16th International Conference on Biomedical Engineering　2016/12

  44. Numerical analysis of cell adhesion in capillary flow

    NAOKI TAKEISHI, YOHSUKE IMAI, SHUNICHI ISHIDA, TOSHIHIRO OMORI, ROGER KAMM, TAKUJI ISHIKAWA

    The 69th Annual Meetin g of The American Physical Society, Bulletin of the American Physical Society, DED 2016　2016/11

  45. Deformable micro torque swimmer International-presentation

    T. Ishikawa, T. Tanaka, T. Omori, Y. Imai

    69th Annual Meeting of the Division of Fluid Dynamics　2016/11

  46. Asymmetry of Arrangement Induces Phase Synchronization in Mouse Node Cilia International-presentation

    K. Okumura, S. Nishikawa, T. Omori, T. Ishikawa, A. Takamatsu

    26th IUPAP International Conference on Statistical Physics　2016/07

  47. Phase locking due to asymmetric arrangement in a model of three identical cilia

    Okumura K, Nishikawa S, Omori T, Ishikawa T, Takamatsu A

    Meeting Abstracts of the Physical Society of Japan　2016

    More details Close

    &lt;p&gt;マウス胚のノード繊毛は時計回りの回転運動をする。少数繊毛系等でこの回転運動が位相同期することが観測されている。我々は繊毛間の流体的な相互作用を境界要素法により数値的に求め、振動子モデルとして繊毛間の位相差を位相縮約法により解析した。本発表では同質な繊毛パラメータの場合、2繊毛系では位相同期が起こらない一方、3繊毛系では繊毛の空間的な配置の非対称性により位相同期が起こることを報告する。&lt;/p&gt;

  48. Deformable micro torque swimmer

    TAKUJI ISHIKAWA, TOMOYUKI TANAKA, TOSHIHIRO OMORI, YOHSUKE IMAI

    68th Annual Meeting of the Division of Fluid Dynamics, Bulletin of the American Physical Society, DFD 2015　2015/11/01

  49. Simulations of a swimming microorganism near an fluid-air or an fluid-solid interface

    Junichi Manabe, Toshihiro Omori, Yohsuke Imai, Takuji Ishikawa

    Computational Fluid Dynamics (CFD) in Medicine and Biology II　2015/09/01

  50. Intergrated Computational Biomechanics of the Flow Phenomena in the Living Body

    Takami Yamaguchi, Yosuke Imai, Toshihiro Omori, Kenji Kikuchi, Takuji Ishikawa

    Computational Fluid Dynamics (CFD) in Medicine and Biology II　2015/09/01

  51. Mechanics of Nodal Cilia in Early Mouse Embryo International-presentation

    T. Omori, H. Sugai, Y. Imai, T. Ishikawa

    The 8th Asian-Pacific Conference on Biomechanics　2015/09

  52. Development of a Numerical Model of Cytoskeleton Dynamics International-presentation

    F. Saito, Y. Imai, S. Ishida, T. Omori, T. Ishikawa

    The 8th Asian-Pacific Conference on Biomechanics　2015/09

  53. A Numerical Simulation of Cytoadhesion and Rosette Formation of Red Blood Cells Infected by Malaria International-presentation

    Y. Imai, Y. Ichikawa, S. Ishida, D. Matsunaga, S. Nix, T. Omori, T. Yamaguchi, T. Ishikawa

    The 8th Asian-Pacific Conference on Biomechanics　2015/09

  54. Swimming Behavior of a Model Ciliate near a Fluid-Air or a Fluid-Solid Interface International-presentation

    J. Manabe, T. Omori, Y.Imai, T. Ishikawa

    The 8th Asian-Pacific Conference on Biomechanics　2015/09

  55. Simulations of a swimming microorganism near an fluid-air or an fluid-solid interface International-presentation

    J. Manabe, T. Omori, Y.Imai, T. Ishikawa

    Computational Fluid Dynamics in Medicine and Biology II　2015/08

  56. Cellular Scale Physiological Flow: Active Swimming Sperm Cells and Passive Flowing Red Blood Cells

    Toshihiro Omori, Takuji Ishikawa, Yohsuke Imai, Takami Yamaguchi

    13th U.S. National Congress on Computational Mechanics　2015/07/01

  57. A Computational Study Of Red Blood Cells In Stokes Flow: From Single Cellular Mechanics To Suspension Rheology

    Toshihiro Omori, Yohsuke Imai, Takami Yamaguchi, Takuji Ishikawa

    SB3C2015　2015/06/01

  58. A computational study of red blood cells in Stokes flow: from single cellular mechanics to suspension rheology International-presentation

    T. Omori, Y.Imai, T. Yamaguchi, T. Ishikawa

    Summer Biomechanics, Bioengineering, and Biotransport Conference　2015/06

  59. Rheology of A Red Blood CEll Suspension Computing with A Boundary Element-Finite Wlement Coupled Method

    Toshihiro Omori, Yohsuke Imai, Takuji Ishikawa

    The 18th International Conference on Finite Elements in Flow Problems FEF2015　2015/03/01

  60. 16pCX-1 Parameter dependence on synchronization in a model of two nodal cilia

    Okumura K, Nishikawa S, Omori T, Ishikawa T, Takamatsu A

    Meeting Abstracts of the Physical Society of Japan　2015

  61. 22pBL-8 Synchronized oscillation in a model of three nodal cilia with hydrodynamic interaction

    Okumura K, Nishikawa S, Omori T, Ishikawa T, Takamatsu A

    Meeting Abstracts of the Physical Society of Japan　2015

  62. Swimming behavior of a model microorganism at a fluid-air interface International-presentation

    J. Manabe, Kohei Kyoya, T. Omori, Y.Imai, T. Ishikawa

    The Sixth International Symposium on Aero Aqua Bio-mechanisms　2014/11

  63. Development of a numerical model for analysis of ciliary motions

    H. Sugai, T. Omori, Y. Imai, T. Ishikawa

    7th WORLD CONGRESS OF BIOMECHANICS　2014/07/10

  64. Collective swimming of ellipoidal squimers

    Takuji Ishikawa, Kohei Kyoya, Daiki Matsunaga, Yohsuke Imai, Toshihiro Omori

    Dyna Caps 2014　2014/07/10

  65. Numerical Analysis of Capsule Suspensions Containing Two Different siza Capsules

    Hiroki Ito, Yohsuke Imai, Daiki Matsunaga, Toshihiro Omori, Takami Yamaguchi, Takuji Ishikawa

    Dyna Caps 2014　2014/07/10

  66. Nutrient Uptake in a Suspension of Model Microorganisms

    Takuji Ishikawa, Shunsuke Kajiki, Yohsuke Imai, Toshihiro Omori

    Internationnal Symposium on Integrated Nanobiomechanics　2014/07/05

  67. Development of an Intracellular Structure Model for Ciliary Motion Analysis

    Hiroto Sugai, Toshihiro Omori, Yohsuke Imai, Takami Yamaguchi, Takuji Ishikawa

    Internationnal Symposium on Integrated Nanobiomechanics　2014/07/05

  68. Rheological analysis of capsule suspensions containing different size capsules International-presentation

    H. Ito, Y. Imai, D. Matsunaga, T. Omori, T. Ymaguchi, T. Ishikawa

    11th World Congress on Computational Mechanics　2014/07

  69. Numerical analysis of capsule suspensions containing two different size capsules International-presentation

    H. Ito, Y. Imai, D. Matsunaga, T. Omori, T. Ymaguchi, T. Ishikawa

    Dynacaps 2014　2014/07

  70. Collective swimming of ellipsoidal squirmers International-presentation

    T. Ishikawa, K. Kyoya, D. Matsunaga, Y.Imai, T. Omori

    Dynacaps 2014　2014/07

  71. Nutrient uptake in a suspension of model microorganisms International-presentation

    T. Ishikawa, S. Kajiki, Y. Imai, T. Omori

    International Symposium on integrated nano-biomechanics　2014/07

  72. Development of an intracellular structure model for ciliary motion analysis International-presentation

    S. Hiroto, T. Omori, Y. Imai, T. Yamaguchi, T. Ishikawa

    International Symposium on integrated nano-biomechanics　2014/07

  73. Rheology of a Red Blood Cell Suspension from Dilute to Semi-dilute Regime International-presentation

    T. Omori, Y. Imai, T. Yamaguchi, T. Ishikawa

    International Symposium on integrated nano-biomechanics　2014/07

  74. Nutrient uptake in a suspension of model microorganisms

    Takuji Ishikawa, Shunsuke Kajiki, Yohsuke Imai, Toshihiro Omori

    COMPSAFE　2014/04/02

  75. Effect of Aeration on the Bioconvection Pattern in a Microalgae Suspension

    Y. Nonaka, H. Ueno, K. Numayama, T. Omori, Y. Imai, T. Yamaguchi, T. Ishikawa

    APCB2013 Proceedings　2013/08/30

  76. Integrated Biomechanics for Physiological Flow Problems

    T. Yamaguchi, Y. Imai, T. Omori, H. Ueno, K. Numayama-Tsuruta, T. Ishikawa

    APCB2013 The7thAsian Pacific Conference on Biomechanics　2013/08/29

  77. Effect of Aeration on the Biconvection Pattern in a Microalgae Suspension International-presentation

    Y. Nonaka, H. Ueno, K. Numayama-Tsuruta, T.Omori, Y. Imai, T. Yamaguchi, T. Ishikawa

    The 7th Asian Pacific Conference on Biomechanics　2013/08

  78. 103 Aggregation structure of algae in forced circulation bubbly flow

    NONAKA Yuki, UENO Hironori, NUMAYAMA-TSURUTA Keiko, OMORI Toshihiro, IMAI Yosuke, YAMAGUCHI Takami, ISHIKAWA Takuji

    The Proceedings of Conference of Tohoku Branch　2013

  79. C107 Bioconvection of micro algae cells under an aeration condition

    NONAKA Yuki, UENO Hirinori, NUMAYAMA Keiko, OMORI Toshihiro, IMAI Yosuke, YAMAGUCHI Takami, ISHIKAWA Takuji

    The Proceedings of the JSME Conference on Frontiers in Bioengineering　2013

  80. J027013 Effect of aeration on the bio-convection of micro algae cells

    NONAKA Yuki, UENO Hironori, NUMAYAMA Keiko, OMORI Toshihiro, IMAI Yohsuke, YAMAGUCHI Takami, ISHIKAWA Takuji

    The Proceedings of Mechanical Engineering Congress, Japan　2013

    More details Close

    Bioconvection patterns are often observed in microalgae suspensions of randomly, but on average upwardly, swimming microalgae which are little denser than water. When we culture microalgae in the laboratory, we usually add aeration for mixing the culture fluid and supplying oxygen and carbon dioxide. However, the effect of aeration on the bioconvection pattern and the transport phenomena in the suspension is unclear. In this study, we investigated bioconvection pattern in a suspension of Chlamydomonas reinhardtii under the condition with aeration. Bioconvection pattern in a cylindrical container was visualized by red illumination, and white light for phototaxis could be added from above. Small bubbles were injected by a needle connected to a syringe. Observation of bioconvection patterns of microalgae suspension with aeration showed three kinds of flow patterns depending on the bubble flow rate. When there was no bubble flow, conventional bioconvection was dominant. When flow rate was low, observed pattern in the cylindrical container was split into two flow regions, where the bioconvection and the bubble flow were dominant respectively. When flow rate was high, bubble flow became dominant and no clear bioconvection was observed. Such changes in the bioconvection pattern have not been reported before. These findings are important to understand the transport phenomena in algae suspensions in engineering settings.

  81. 3E15 Measurement of ciliary flow generated on the surface of tracheal lumen

    KIYOTA Koki, UENO Hironori, ISHIKAWA Takuji, NUMAYAMA Keiko, IMAI Yohsuke, OMORI Toshihiro, YAMAGUCHI Takami

    The Proceedings of the Bioengineering Conference Annual Meeting of BED/JSME　2013

  82. 計算生体力学シミュレーションによるミクロからマクロスケールの生体機能の解析

    山口 隆美, 今井 陽介, 水野 文雄, 大森 俊宏, 上野 裕則, 沼山 恵子, 石川 拓司

    バイオメカニズム学術講演会予稿集　2012/12

  83. Analysis of red blood cell behavior in a narrow tube

    H. Hosaka, T. Omori, Y. Imai, T. Yamaguchi, T. Ishikawa

    Bulletin of the American Physical Society 65th Annual Meeting of the APS Division of Fluid Dynamics　2012/11

  84. Measurement of ciliary flow generated on the surface of tracheal lumen

    K. Kiyota, H. Ueno, T. Ishikawa, K. Numayama-Tsuruta, Y. Imai, T. Omori, T. Yamaguchi

    Bulletin of the American Physical Society 65th Annual Meeting of the APS Division of Fluid Dynamics　2012/11

  85. Off-plane motion of a non-spherical capsule in simple shear flow

    T. Omori, T. Ishikawa, Y. Imai, T. Yamaguchi

    Bulletin of the American Physical Society 65th Annual Meeting of the APS Division of Fluid Dynamics　2012/11

  86. Off-Plane motion of a non-spherical capsule in simple shear flow International-presentation

    T. Omori, T. Ishikawa, Y. Imai, T. Yamaguchi

    65th Annual Meeting of the Division of Fluid Dynamics　2012/11

  87. Analysis of red blood cell behavior in narrow tube International-presentation

    H. Hosaka, T. Omori, Y. Imai, T. Yamaguchi, T. Ishikawa

    65th Annual Meeting of the Division of Fluid Dynamics　2012/11

  88. Development of a GPU-Implemented BEM solver for biological cell suspensions

    Y. Imai, D. Matsunaga, K. Kyoya, T. Omori, T. Ishikawa, T. Yamaguchi

    International Computational Mechanics Symposium 2012　2012/10

  89. Development of a GPU- implemented BEM solver for biological cell suspensions International-presentation

    Y. Imai, D. Matsunaga, K. Kyoya, T. Omori, T. Ishikawa, T. Ymaguchi

    International Computational Mechanics Symposium　2012/10

  90. ストークス流れ中の非球形カプセルの配向現象

    石川拓司, 大森俊宏, 今井陽介, 山口隆美

    京都大学数理解析研究所講究録　2012/09/01

  91. Reorientaion of a non-spherical micro-capsule in shear flow International-presentation

    T. Ishikawa, T. Omori, Y. Imai, T. Yamaguchi

    International Union of Theoretical and Applied Mathematics　2012/07

  92. Computational biomechanics of physiological flow

    T. Yamaguchi, T. Ishikawa, Y. Imai, H. Ueno, K. Numayama-Tsuruta, T. Omori

    Biological Flow: A Conference to Celebrate the 70th Birthday of Timothy J. Padley FRS　2012/03/20

  93. Rheology of a dilute suspention of red blood cells in simple shear flow

    T. Omori, T. Ishikawa, Y. Imai, T. Yamaguchi

    18th International Symposium of Tohoku University Global COE Program, Global Nano-Biomedical Engineering Education and Research Network Centre, Nano-Biomedical Engineering in the East Asian-Pacific Rim Region　2012/03

  94. Rheology of a dilute suspension of red blood cells in simple shear flow International-presentation

    T. Omori, T. Ishikawa, Y. Imai, T. Yamaguchi

    Nano-Biomedical Engineering in the East Asian-Pacific Rim Region　2012/03

  95. Multi-GPU computing of capsule flow using boundary integral method

    D. Matsunaga, Y. Imai, T. Omori, T. Ishikawa, T. Yamaguchi

    5th East Asian Pacific Student Workshop on Nano-Biomedical Engineering　2011/12

  96. High performance GPU computing of capsule flow using boundary integral method International-presentation

    D. Matsunaga, Y. Imai, T. Omori, T. Miki, T. Ishikawa, T. Yamaguchi

    Japan-Portugal Nano-BME Symposium　2011/07

  97. High performance GPU computing of capsule flow using boundary integral method

    D.Matsunaga, Y.Imai, T.Omori, T.Miki, T.Ishikawa, T.Yamaguchi

    Proc. Japan-Portugal Nano-BME Symp　2011/06

  98. Capsule flow analysis using GPU computation

    D. Matsunaga, Y. Imai, T. Omori, T. Miki, T. Ishikawa, T. Yamaguchi

    Microscale Modeling in Biomechanics and Mechanobiology Program and Abstract　2011/05

  99. Multi-GPU computing of capsule flow using boundary integral method International-presentation

    D. Matsunaga, Y. Imai, T. Omori, T. Ishikawa, T. Yamaguchi

    East Asian Pacific Student Workshop on Nano-Biomedical Engineering　2010/12

  100. Effect of Membrane Modeling on the Capsule Deformation: Comparison between a Spring Network and Continuum Models

    T.Omori, T.Ishikawa, D.Barthes-Biesel, A.-V.Salsac, Y.Imai, T.Yamaguchi

    6th World Congress of Biomechanics Abstracts　2010/08

  101. Effect of membrane modeling on the capsule deformation: comparison between a spring network model and continuum models International-presentation

    T. Omori, T. Ishikawa, D. Barthes-Biesel, A.-V. Salsac, J. Walter, Y. Imai, T. Yamaguchi

    6th World Congress of Biomechanics　2010/08

  102. Impact of membrane modeling in analysing deformation of a capsule:comparison between a spring network model and constitutive laws

    T.Omori, T.Ishikawa, D.Barthes-biesel, A.V.Salsac, Y.Imai, T.Yamaguchi

    Proc. 4th ECCM　2010/05

  103. Impact of membrane modeling in analysing deformation of a capsule; comparison between a spring network model and constitutive laws International-presentation

    T. Omori, T. Ishikawa, D. Barthes-Biesel, A.-V. Salsac, J. Walter, Y. Imai, T. Yamaguchi

    European Conference on Computational Mechanics　2010/05

  104. Impact of membrane modeling on the deformation analysis of a capsule International-presentation

    T. Omori, T. Ishikawa, D. Barthes-Biesel, Y. Imai, T. Yamaguchi

    East Asian Pacific Student Workshop on Nano-Biomedical Engineering　2009/12

  105. Modeling of the membrane bending rigidity for calculating red blood cell deformation

    T. Omori, T. Ishikawa, D. Birthes-Biesel, Y. Imai, T. Yamaguchi

    15th Int. Conf. Finite Elements in Flow Problems (FEF09) Abstracts　2009/04

  106. Effect of the membrane bending stiffness on the deformation of a red blood cell International-presentation

    T. Omori, T. Ishikawa, D. Barthes-Biesel, Y. Imai, T. Yamaguchi

    4th Asian Pacific Conference on Biomechanics　2009/04

  107. Modeling of the membrane bending rigidity for calculating red blood cell deformation International-presentation

    T. Omori, T. Ishikawa, D. Barthes-Biesel, Y. Imai, T. Yamaguchi

    International Conference on Finite Elements in Flow Problem　2009/03

  108. Behavior of a red blood cell in a simple shear flow simulated by a boundary element method

    T. Omori, T. Ishikawa, D. Barthes-Biesel, Y. Imai, T. Yamaguchi

    GPBE/NUS-Tohoku Graduate Student Conf. Bioeng., Program & Abstract　2008/12/01

  109. Behaviour of a red blood cell in a simple shear flow simulated by a boundary element method International-presentation

    T. Omori, T. Ishikawa, D. Barthes-Biesel, Y. Imai, T. Yamaguchi

    GPBE/NUS-Tohoku Graduate Student Conference in Bioengineering　2008/12

  110. Behaviour of a red blood cell in a simple shear flow simulated by a boundary element method International-presentation

    T. Omori, T. Ishikawa, D.Barthes-Biesel, Y. Imai, T. Yamaguchi

    Bioengineering 08　2008/10

  111. Behavior of a red blood cell in a simple shear flow simulated by a boundary element method

    T. Omori, T. Ishikawa, D. Barthes-Biesel, Y. Imai, T. Yamaguchi

    Book of Abstracts BIOENGINEERING 08　2008/09

  112. Proposal of mesoscopic analysis method of blood rheology

    M. Nakamura, T. Omori, T. Yamaguchi, S. Wada

    Proceedings of the Third Asian Pacific Conference on Biomechanics (To appear in Journal of Biomechanical Science and Engineering)　2007/11/08

  113. Computational Analysis of a Non-Newtonian Behavior of Blood Flow by an Interactive Calculation of Micro- and Micro- Scale Blood Dynamics

    M. Nakamura, T. Omori, T. Yamaguchi, S. Wada

    The 9th International Symposium on Future Medical Engineering based on Bio-nanotechnology jointly organized with The 19th Bioengineering Conference, 2006 Annual Meeting of BED/JSME　2007/01

  114. Multi-scale simulation of blood flow with the dynamical behaviour of elastic red blood cells International-presentation

    T. Omori, S. Wada, K. Tsubota, T. Yamaguchi

    5th World Congress of Biomechanics　2006/07

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Research Projects 7

  1. A computational model of sperm motility based on hydrodynamics

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Transformative Research Areas (A)

    Institution: Tohoku University

    2024/04/01 - 2026/03/31

  2. Study on active transport phenomena for predicting and controlling biological active matter

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (S)

    Institution: Tohoku University

    2021/07/05 - 2026/03/31

  3. 薬剤輸送を目指した柔らかいマイクロスイマーの開発

    石川 拓司, 菊地 謙次, ニックス ステファニー, 大森 俊宏

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 国際共同研究加速基金(国際共同研究強化(B))

    Institution: 東北大学

    2021/10/07 - 2025/03/31

  4. Upgrading Microbial Biomechanics

    Ishikawa Takuji

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (A)

    Institution: Tohoku University

    2017/04/01 - 2021/03/31

    More details Close

    By using an original method that carefully builds up physical laws from the nanoscale to the macroscale, we have clarified the behavior and biological functions of sperm, microalgae, ciliates, E. coli, yeast, and other organisms under mechanical environments. We succeeded in analyzing through the scale hierarchy from the movement of ciliary axonemes driven by molecular motors, synchronization of flagellar movement, swimming and biological responses of ciliates with many flagella, two-body interactions and cooperative swimming, rheology and diffusion properties as a continuum, cell growth and accumulation, and so on. These results were published in a total of 48 peer-reviewed journal articles, including two in PNAS, one in Science Adv, and six in J Fluid Mech. In addition, 8 press releases were issued to widely publicize the research results.

  5. Integrated nano-biomechanics

    YAMAGUCHI Takami, ISHIKAWA Takuji, UENO Hironori, MIZUNO Fumio, OMORI Toshihiro, MATSUKI Noriaki, TANAKA Tetsu, SHIMOGONYA Yuji, NIX Stephanie, NUMAYAMA Keiko, IMAI Yohsuke

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Specially Promoted Research

    Institution: Tohoku University

    2013 - 2017

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    We have established integrated nano-biomechanics by modeling multi-scale physical and biomedical phenomena from the molecular level. By using the established model, we succeeded to numerically simulate various diseases, such as an infectious disease, and developed novel methodologies for medical diagnosis and treatments based on quantitative predictions. Besides, we developed biochips to separate or detect cancer cells and bacteria. These findings have been published as 50 peer reviewed journal papers.

  6. 生体流れに関わる疾患の診断・治療・予防のための計算ナノバイオメカニクスの新展開

    山口 隆美, 大森 俊宏, 沼山 恵子, 今井 陽介, 上野 裕則

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 基盤研究(S)

    Institution: 東北大学

    2011/05/31 - 2014/03/31

    More details Close

    平成25年度（平成25年4月1日～平成25年4月25日）の研究内容は，細胞スケールにおける生体力学および分子生物学の融合を目指したシミュレーション技術の開発であり，主な成果は以下のとおりである． (1) 平成24年度に開発した細胞の接着に関連するligand-receptor結合の計算力学モデルについて，これを格子ボルツマン法と有限要素法に基づく流体－膜連成計算手法へと導入し，血小板血栓形成，マラリア感染赤血球の血管内皮細胞上の回転運動，がん細胞の血管内皮細胞への接着を対象としたシミュレーション手法の開発に着手した． (2) 平成24年度にクライオ電子線トモグラフィー法を用いて解明した気管繊毛の三次元内部構造を考慮し，ダイニン分子の滑り運動に由来する個々の気管繊毛の運動と，これによって駆動される周囲の流れ場の連成シミュレーション手法の開発に着手した． (3) 平成24年度までに赤血球の希薄・準希薄懸濁液を対象として，境界要素法と有限要素法に基づく流体－膜連成計算手法を開発し，循環器のマクロスケールの解析で必要となる粒子応力テンソル，自己拡散テンソルを算出している．これを赤血球濃厚懸濁液へと拡張するため，細胞濃厚懸濁液を対象とした大規模GPUシミュレーション手法の開発に着手した． (4) 平成24年度に開発した実形状の胃に対する液体食物流動（食物攪拌）の計算力学モデルについて，これを相の異なる液体や固体運動を連成する手法へと改良し，様々な食物および胃液などの流動を解析するための計算力学モデルの開発に着手した．

  7. 血中物質輸送構造解明に向けた計算生体力学的研究 : 赤血球の微細な流動構造に着目して

    大森 俊宏

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 特別研究員奨励費

    Institution: 東北大学

    2009 - 2011

    More details Close

    血液は一様な流体ではなく,多数の血液細胞が流動する懸濁液である.そのため,血液内の物質輸送を定量化するためには,流動する血液細胞の挙動を解析する必要がある.本研究では,主たる血液細胞である赤血球の流動を解析することで,血液の物質輸送を力学的に定量化することを最終目的とする. 赤血球は核を持たない特殊な細胞であり,その流動特性は赤血球膜と膜内外の流体運動によって決定される.本研究では,超弾性体膜を持つカプセルとして赤血球をモデル化し,有限要素法と境界要素法を用いて流体構造連成解析を行う. 当該年度では,開発した赤血球モデルを用いて,せん断流れ場における赤血球の運動や,赤血球膜面応力の解析を行った.さらに,赤血球の二体干渉を解析することにより,準希薄懸濁液下でのレオロジー特性や,赤血球自己拡散について解析を行った. あるせん断速度下において,ランダム配向された赤血球が,特定の向きに収束する様子が確認された.配向が収束することにより,周期的な運動から定常的な運動へと遷移することが分かった.これらの現象は,過去の実験結果と矛盾することはなく,赤血球の運動メカニズム解明に向けた重要な知見になる.続いて,赤血球の膜面主応力や膜面圧力を解析することで,膜面応力とせん断速度の関係を明らかにした.膜面応力は,溶血や赤血球のメカノトランスダクションを議論する際に重要な物理量である. 懸濁液内の物理を記述するには,赤血球同士の流体力学的干渉を考慮する必要がある.準希薄懸濁液下では,赤血球の二体干渉が支配的になることから,二体干渉を解析することで準希薄懸濁液特性の解析を行った.せん断粘性が赤血球体積率に対して2次関数的に増加すること,流れ場によって赤血球は非等方的に拡散することが分かった.これらの結果は,複雑な懸濁液の力学を理解するため重要な基礎知見となる.

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Teaching Experience 5

  1. 学問論演習　東北大学

  2. 計画及び製図Ⅱ　東北大学工学部機械知能航空工学科

  3. 連続体力学　東北大学大学院工学研究科

  4. 力学　東北大学工学部 機械知能・航空工学科

  5. 医用機械・電気工学実習　東北大学大学院医工学研究科

Social Activities 1

  1. 出前講義

    出前講義

    2024/10/09 - 2024/10/09

Media Coverage 11

  1. 心臓は左…体の「左右」はどう決まる? カギは2種類の「毛」の共演

    朝日新聞デジタル

    2023/01

    Type: Newspaper, magazine

  2. 体の左右非対称を決めるのは、化学物質ではなく「力」と判明

    YahooJapanニュース

    2023/01

    Type: Internet

  3. 哺乳類の体のつくりが左右非対称 その仕組みは？

    NHK NEWS WEB

    2023/01

    Type: TV or radio program

  4. 臓器づくりの左右非対称性 発生初期 機械的な力で決定

    科学新聞

    2023/01

    Type: Newspaper, magazine

  5. ［特集］群れを成す個体たち 遊泳効率からみた多細胞化への進化と群れる利益

    リバネス株式会社 研究応援 Vol.21

    2021/03

    Type: Newspaper, magazine

  6. 微生物は多繊毛化によって最大遊泳効率を獲得している

    ユサコ株式会社 日本人論文紹介

    2020/12

    Type: Newspaper, magazine

  7. 精子は互いに助け合い卵子を目指す

    読売新聞オンライン yomiDr.

    2020/12

    Type: Newspaper, magazine

  8. 東北大、微生物が進化の過程で獲得した省エネ泳法を解明

    日本経済新聞

    2020/11

    Type: Newspaper, magazine

  9. 微生物が進化の過程で獲得した省エネ泳法を解明 細胞の連携が最適な遊泳効率をもたらす／東北大

    日本の研究.comニュース

    2020/11

    Type: Internet

  10. 競争ではなく協力...「精子は助け合って泳ぐ」東北大が発表 不妊治療へ期待

    テレ東ニュース

    2020/11

    Type: TV or radio program

  11. 単細胞から多細胞生物へ、進化の謎を解き明かす鍵を解明 東北大

    BIGLOBEニュース

    2020/11

    Type: Internet

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