[1] Tohoku Inst Technol, Fac Engn, Dept Informat & Commun Engn, Sendai, Miyagi 982, Japan
[2] Tohoku Univ, IDAC, Dept Ubiquitous Sensing, Sendai, Miyagi 980, Japan
[3] Tohoku Univ, Grad Sch Engn, Dept Management Sci & Technol, Sendai, Miyagi 980, Japan
[4] Tohoku Univ, IDAC, Dept Funct Brain Imaging, Sendai, Miyagi 980, Japan
[5] Kobe Univ, Sch Med, Fac Med, Kobe, Hyogo 650, Japan