[1] Department of Mechanical Engineering, Toyohashi University of Technology, Toyohashi, Aichi 441-8580, Japan
[2] Department of Mechanical Engineering, Ibaraki University, Hitachi, Ibaraki 316-8511, Japan
[3] Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Chiyoda, Tokyo 101-0062, Japan