1. Department of Mechanical Engineering, Yamaguchi University, Ube, 755-8611, Japan
2. Department of Mechatronics and Precision Engineering, Tohoku University, Aoba-yama 04, Sendai, 980-8579, Japan
3. Tohoku Kousai Hospital, Aoba-ku Kokubun-Cho 2-3-11, Sendai, Japan