Journal of Biomechanical Science and Engineering
Online ISSN : 1880-9863
ISSN-L : 1880-9863
Volume 6, Issue 1
Displaying 1-5 of 5 articles from this issue
  • Mahtab Uddin AHMMED, Hiroyuki HIRAHARA, Tomonori YAMAMOTO, Katsuya IWA ...
    2011 Volume 6 Issue 1 Pages 1-14
    Published: 2011
    Released on J-STAGE: March 01, 2011
    An oscillatory flow in human lung was investigated with a real scale model channel experimentally. One objective of the present study is to clarify the gas exchange mechanism in the peripheral channel, e.g. from the 18-th to 20-th generations, which are the leading region of gas exchanges. The second object is the inspection of the flow convection under the HFOV (high frequency oscillatory ventilation) condition. The experiment was carried out with a real scale two-dimensional model of airway, instead of using a similarity model, in order to take into account the practical condition of HFOV. The velocity profiles were obtained from ensemble mean measurements and the air trajectories were demonstrated with the ensemble mean velocities in the test section. It was confirmed that the air trajectories of expiration were deviated from those of inspiration in the intermediate zone of our channel. It was predicted that a convective flow mixing might be took place depending on the geometric configuration and the asymmetric compliance ratios of the bronchioles.
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  • Qilong SUN, Hirohisa MORIKAWA, Keiichi UEDA, Hirokazu MIYAHARA, Motomu ...
    2011 Volume 6 Issue 1 Pages 15-25
    Published: 2011
    Released on J-STAGE: March 14, 2011
    The aim of this paper is to study the bending properties of tail flukes of a dolphin. The bending test was carried out to obtain the displacements on different test points of a fluke. The Young’s moduli of the ligamentous layer and the dense connective tissue in the flukes were obtained from the tensile test and the compression test. In order to establish an FEM model for bending deformation of the flukes, the thickness of the flukes was measured with two laser displacement sensors, and the thickness of the ligamentous layer was also measured. The displacements obtained by the simulation of the FEM model were compared with those of the bending test of the experiments. It was found that the model could be helpful to investigate the relationship between the hydrodynamic force acted on the tail flukes of a dolphin and the deformation of the tail flukes.
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  • Makoto KUMON, Shuji UOZUMI
    2011 Volume 6 Issue 1 Pages 26-39
    Published: 2011
    Released on J-STAGE: April 07, 2011
    This paper proposes a biologically inspired binaural auditory system to localize a mobile sound source. The robot considered in this paper has two microphones installed on a mobile platform to provide binaural hearing. An extended Kalman filter (EKF) is adopted to fuse the interaural time difference of arrival, which includes both the Doppler shift and the motion of the auditory system itself. The covariance matrix of EKF is utilized to determine a control policy based on optimizing the localization performance. Numerical simulations validate the proposed approach.
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  • Ryosuke NANSAI, Takuya SUZUKI, Kazunori SHIMOMURA, Wataru ANDO, Norima ...
    2011 Volume 6 Issue 1 Pages 40-48
    Published: 2011
    Released on J-STAGE: April 07, 2011
    We have been developing a new tissue engineering technique for cartilage repair using a scaffold-free tissue engineered construct (TEC) bio-synthesized from synovium-derived mesenchymal stem cells (MSCs). A round-shaped chondral defect of 8.5 mm in diameter and 2.0 mm in depth created on the medial condyle of immature (4-month-old) and mature (12-month-old) porcine femur was filled with the TEC. Six months after surgery, a cylindrically shaped specimen of 4 mm in diameter and 4-5 mm in depth was extracted. Stiffness measurements were carried out on the specimen using an AFM after the surface image of the specimen was obtained. The TEC-treated tissues exhibited more irregular surface as compared with normal cartilage, regardless of animal maturity. The stiffness of the superficial layer of the TEC-treated tissue was significantly lower than those of the normal cartilage, indicating 6.8±2.3 mN/m in the immature group and 8.8±2.3 mN/m in the mature group. Histological observation indicated that the defects were repaired with a hyaline cartilage-like tissue with positive Safranine O staining, regardless of animal maturity. However, the superficial layer of the repaired tissues was negatively stained with Safranine O. The present study suggests that the recovery of the superficial layer is delayed in both immature and mature animals although the treatment with TEC enhances the repair of partial chondral defects.
    Editor's pick

    ★Paper of the Year 2011

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  • Toshikazu MATSUI, Nobuaki NAKAZAWA
    2011 Volume 6 Issue 1 Pages 49-62
    Published: 2011
    Released on J-STAGE: April 07, 2011
    We have already formulated the human three-joint arm’s optimal control model with its hand-joint’s feedback mechanism and have clarified that the model is effective in reproducing human unconstrained reaching movements including the experimental fact that the hand-joint angle hardly changes over the entire movement. For validating the proposed model, this paper applies it to reproducing human constrained reaching movements in which the hand has to take a specified posture at the final point as in the case of holding a cup’s handle with fingertips. The following results were obtained: (1) the proposed model was able to move its hand joint despite the existence of the feedback mechanism preventing the hand-joint angle from changing; (2) the proposed model succeeded at reproducing the measured hand trajectories and the measured angular transition characteristics for the hand joint in most of the constrained reaching movements. These results suggest that the proposed model has the ability to simulate human reaching movements regardless of whether they are unconstrained or constrained, i.e., it can be a general and plausible model for the human three-joint arm's control mechanism. Moreover, it is computationally considered that the hand-joint’s angular transition characteristic depends on the average of the resultant torque around the hand joint over the entire movement.
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