1. Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan
2. Tokai University School of Medicine, 143 Shimokasuya, Isehara, Kanagawa 259-1193, Japan
3. Department of Medical Informatics, Kagawa University Hospital, Miki-cho Ikenobe, Kagawa 761-0793, Japan