1. National Institute of Technology, Toyama College, 1-2 Ebie-Neriya, Imizu, Toyama 933-0293, Japan
2. National Institute of Technology, Ishikawa College, Kitachujo, Tsubata, Ishikawa 929-0392, Japan
3. National Institute of Technology, Toyama College, 13 Hongo-machi, Toyama 939-8630, Japan
4. Department of Clinical Engineering, Faculty of Health Sciences, Komatsu University, 1-14 Mukaimotoori-machi, Komatsu, Ishikawa 923-0961, Japan