Hideyuki Kimpara
Toyota
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Publication
Featured researches published by Hideyuki Kimpara.
Journal of Biomechanical Engineering-transactions of The Asme | 2006
Hideyuki Kimpara; Mariko Iwamoto; Isao Watanabe; Kensaku Miki; Jong B. Lee; King H. Yang; Albert I. King
The mass density, Youngs modulus (E), tangent modulus (Et), and yield stress (sigma y) of the human ribs, sternum, internal organs, and muscles play important roles when determining impact responses of the chest associated with pendulum impact. A series of parametric studies was conducted using a commercially available three-dimensional finite element (FE) model, Total HUman Model for Safety (THUMS) of the whole human body, to determine the effect of changing these material properties on the predicted impact force, chest deflection, and the number of rib fractures and fractured ribs. Results from this parametric study indicate that the initial chest apparent stiffness was mainly influenced by the stiffness and mass density of the superficial muscles covering the torso. The number of rib fractures and fractured ribs was primarily determined by the stiffness of the ribcage. Similarly, the stiffness of the ribcage and internal organs contributed to the maximum chest deflection in frontal impact, while the maximum chest deflection for lateral impact was mainly affected by the stiffness of the ribcage. Additionally, the total mass of the whole chest had a moderately effect on the number of rib fractures.
Traffic Injury Prevention | 2010
Hideyuki Kimpara; Jong B. Lee; King H. Yang; Albert I. King
Objective: The purpose of this study was to determine the effects of body weight, height, and rib cage area moment of inertia on human chest impact responses in frontal pendulum impacts. Methods: A series of parametric studies was conducted with 11 cases of finite element (FE) analysis using a commercially available three-dimensional (3-D) FE model of the whole human body, Total HUman Model for Safety (THUMS). Selected parameters in this study were body weight, height, and area moment of inertia of the rib cage and of the ribs alone. Three body sizes assumed were those of a large male (AM95), a mid-sized male (AM50), and a small female (AF05). The initial impact response, maximum chest force, maximum deflection, maximum compression ratio, and the number of rib fractures and fractured ribs were examined for statistical analysis. Results: Body weight and height of the human body do not show any correlation with any injury variable considered in this study. However, area moment of inertia of the rib cage correlated (r = −0.86 and p = 0.001) with maximum chest compression ratio, which is the best predictor of the number of rib fractures. Conclusion: The area moment of inertia of the rib cage or ribs alone would affect the response and injury variables in frontal pendulum impacts.
2004 ASME International Mechanical Engineering Congress and Exposition, IMECE 2004 | 2004
Hideyuki Kimpara; Masami Iwamoto; Isao Watanabe; Kazuo Miki; Jong B. Lee; King H. Yang; Albert I. King
The mass density, Young’s modulus (E), tangent modulus (Et ) and yield stress (σy ) of the human ribs, sternum, internal organs and muscles play important roles when determining impact responses of the chest associated with pendulum impact. A series of parametric studies was conducted using a commercially available three-dimensional finite element (FE) model, Total HUman Model for Safety (THUMS) of the whole human body, to determine the effect of changing these material properties on the impact force, chest deflection, and the number of rib fractures and fractured ribs. Results from this parametric study indicate that the initial chest stiffness was mainly influenced by the mass density of the muscles covering the torso. The number of rib fractures and fractured ribs were primarily determined by E, Et and σy of the ribcage and sternum. Similarly, the E, Et and σy of the ribcage, which is defined as the bony skeleton of the chest, and sternum and E of the internal organs contributed to the maximum chest deflection in frontal impact, while the maximum chest deflection for lateral impact was mainly affected by the E, Et and σy of the ribcage.Copyright
Neural Computation | 2018
Kyuengbo Min; Masami Iwamoto; Shinji Kakei; Hideyuki Kimpara
Humans are able to robustly maintain desired motion and posture under dynamically changing circumstances, including novel conditions. To accomplish this, the brain needs to optimize the synergistic control between muscles against external dynamic factors. However, previous related studies have usually simplified the control of multiple muscles using two opposing muscles, which are minimum actuators to simulate linear feedback control. As a result, they have been unable to analyze how muscle synergy contributes to motion control robustness in a biological system. To address this issue, we considered a new muscle synergy concept used to optimize the synergy between muscle units against external dynamic conditions, including novel conditions. We propose that two main muscle control policies synergistically control muscle units to maintain the desired motion against external dynamic conditions. Our assumption is based on biological evidence regarding the control of multiple muscles via the corticospinal tract. One of the policies is the group control policy (GCP), which is used to control muscle group units classified based on functional similarities in joint control. This policy is used to effectively resist external dynamic circumstances, such as disturbances. The individual control policy (ICP) assists the GCP in precisely controlling motion by controlling individual muscle units. To validate this hypothesis, we simulated the reinforcement of the synergistic actions of the two control policies during the reinforcement learning of feedback motion control. Using this learning paradigm, the two control policies were synergistically combined to result in robust feedback control under novel transient and sustained disturbances that did not involve learning. Further, by comparing our data to experimental data generated by human subjects under the same conditions as those of the simulation, we showed that the proposed synergy concept may be used to analyze muscle synergy–driven motion control robustness in humans.
Annals of Biomedical Engineering | 2012
Hideyuki Kimpara; Masami Iwamoto
Stapp car crash journal | 2005
Hideyuki Kimpara; Jong B. Lee; King H. Yang; Albert I. King; Mariko Iwamoto; Isao Watanabe; Kensaku Miki
Stapp car crash journal | 2006
Hideyuki Kimpara; Yuko Nakahira; Masami Iwamoto; Kazuo Miki; Kazuhiko Ichihara; Shunichi Kawano; Toshihiko Taguchi
Stapp car crash journal | 2012
Masami Iwamoto; Yuko Nakahira; Hideyuki Kimpara; Takahiko Sugiyama; Kyuengbo Min
International journal of automotive engineering | 2011
Hideyuki Kimpara; Yuko Nakahira; Masami Iwamoto; Steve Rowson; Stefan M. Duma
PROCEEDINGS OF IRCOBI (INTERNATIONAL RESEARCH COUNCIL ON THE BIOMECHANICS OF INJURY) CONFERENCE 2007, HELD MAASTRICHT, THE NETHERLANDS, SEPTEMBER 2007 | 2007
Takahiko Sugiyama; Hideyuki Kimpara; Masami Iwamoto; Daisuke Yamada; Yuko Nakahira; Masatoshi Hada