1. Faculty of Health Sciences, Tsukuba University of Technology, Ibaraki, Japan
2. Faculty of Library, Information and Media Science, University of Tsukuba, Ibaraki, Japan
3. Center for Innovative Medicine and Engineering, University of Tsukuba, Ibaraki, Japan
4. Faculty of Engineering, Information and Systems, University of Tsukuba, Ibaraki, Japan
5. Center for Cybernics Research, University of Tsukuba, Ibaraki, Japan