1. Advanced Medical Engineering Research Institute, University of Hyogo, 3-264 Kamiya, Himeji, Hyogo 670-0836, Japan
2. Graduate School of Information Science, University of Hyogo, 7-1-28 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047, Japan
3. Division of Rehabilitation Medicine, Graduate School of Medicine, Kobe University, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe, Hyogo 650-0017, Japan