- 著者
- Sandi SUFIANDI Hiromichi OBARA Huai-Che HSU Shin ENOSAWA Naoto MATSUNO Hiroshi MIZUNUMA
- 出版者
- 一般社団法人 日本機械学会
- 雑誌
- Journal of Biomechanical Science and Engineering (ISSN:18809863)
- 巻号頁・発行日
- pp.17-00325, (Released:2017-10-12)
- 参考文献数
- 33
- 被引用文献数
- 5
A sufficient number of functional live hepatocytes delivered to a recipient is necessary for cell therapy. Preventing cell viability loss during the cell injection process is important to improve the clinical outcomes of hepatocyte transplantation. The critical location of cell viability loss is important to identify the causal relationship between the viability loss and cell injection process. In this study, the critical location of cell viability loss was determined experimentally in a rectangular microchannel by microscopic high-speed camera observations. Live hepatocyte distributions were investigated upstream and downstream, and measured on three planes, top, center, and bottom, under horizontally or vertically supplied conditions of the syringe orientation. Sedimented and uniform dispersion conditions of the live hepatocyte distribution at upstream of the microchannel were classified according to observations at horizontal and vertical syringe orientations, respectively. Higher hepatocyte viability loss was found under the sedimented condition. The results suggested that the critical location of hepatocyte viability loss was on the bottom plane of the microchannel. Furthermore, physical causes of the hepatocyte viability loss were found by micro-scale observations of the cell velocity and diameter during the cell injection process. This information may contribute to development of a guideline for the cell injection process to improve hepatocyte transplantation.
- 著者
- NAKASHIMA Motomu ONO Ayako
- 出版者
- The Japan Society of Mechanical Engineers
- 雑誌
- Journal of Biomechanical Science and Engineering (ISSN:18809863)
- 巻号頁・発行日
- vol.9, no.1, pp.JBSE0001-JBSE0001, 2014
- 被引用文献数
- 17
The objectives of this study were to solve computationally the arm stroke in the crawl swimming which maximized the swimming speed for different maximum joint torque conditions, and to investigate the maximum joint torque dependency of the crawl swimming with the optimized arm stroke. In the optimizing calculation, the swimming human simulation model, SWUM, was used for the simulation of the crawl swimming. The maximum joint torque characteristics, which were constructed in the previous study, were imposed as the constraint condition. In order to investigate the maximum joint torque dependency of the optimized arm stroke, four levels of maximum joint torque were prepared. The following findings were obtained from the results of optimization: The maximum swimming speed was realized by shortening the stroke cycle as much as possible although this shortening brought a lower propulsive efficiency as well as a lower stroke length. In a constant maximum joint torque condition, the swimmer does not push the water by turning the palm to the side in the latter half of the underwater stroke at the stroke cycle which brings the maximum swimming speed. The locus of the hand was relatively straight. At the slightly longer stroke cycle, the swimmer pushed the water until the end of the underwater stroke. The locus of the hand was still relatively straight. At the sufficiently longer stroke cycle, the swimmer also pushed the water until the end of the underwater stroke. The locus of the hand, however, became more curved and therefore became a so-called 'S-shaped' stroke.
- 著者
- Kohji OHTA Yoshiyuki TANAKA Isao KAWATE Toshio TSUJI
- 出版者
- 一般社団法人 日本機械学会
- 雑誌
- Journal of Biomechanical Science and Engineering (ISSN:18809863)
- 巻号頁・発行日
- pp.14-00207, (Released:2014-09-16)
- 参考文献数
- 16
- 被引用文献数
- 6
Human can realize flexible and skillful movements by controlling his/her musculoskeletal system and the interactive force with environments appropriately. However it still exist many uncertain biological motor characteristics in human movements even for a simple task. This paper aims to analyze and evaluate acceleration characteristics of the human hand during quick arm motion. First, the dynamic manipulability of end-point via muscle forces, called Human Muscular Mobility Ellipsoid (HMME), is newly defined. Next, the direction-dependent acceleration characteristic of the human hand motion is examined and analyzed its geometrical properties with an approximation ellipses of measured data. It is also discussed the problem that the conventional measures relative to the performance of end-point acceleration cannot represent the geometrical properties of human generated hand acceleration in good agreement with the measured data. Finally, the merits of HMME compared with the conventional measures is then demonstrated with a set of experimental results and computed results: HMME can be utilized in representing the geometric properties of human hand acceleration.
- 著者
- Satoshi UEHARA Makusu TSUTSUI Kentaro DOI Masateru TANIGUCHI Satoyuki KAWANO Tomoji KAWAI
- 出版者
- 一般社団法人 日本機械学会
- 雑誌
- Journal of Biomechanical Science and Engineering (ISSN:18809863)
- 巻号頁・発行日
- vol.8, no.3, pp.244-256, 2013 (Released:2013-07-31)
- 参考文献数
- 23
- 被引用文献数
- 3 4
In the present study, we address theoretical approaches for the experimental results to investigate the flow dynamics of λDNA through a nanochannel in which two nanoelectrodes are integrated. In order to elucidate the relationship between the longitudinal ionic current and the electrophoresis of λDNA in the specific micro/nanofluidics, we develop a theoretical model for the macroscopic fluid dynamics in a Lagrangian framework. The measured current change associated with a single molecule translocation through the channel is explained by the principle of the Coulter counter that allowed to predict the conformation of λDNA. We also analyze the local velocity of λDNA passing through a nanoscaled confined channel. A result from the model is in considerable agreement with the experimental observations for the electrophoretic flow of λDNA. The basic knowledge obtained here may be useful in developing electrical methods for controlling the electrophoretic velocity of single-molecule DNA for realizing the nanopore sequencer.