1. Department of Endoscopic Diagnostics and Therapeutics and 2 Medical Informatics, Kyushu University Hospital, Fukuoka, Japan.
2. Department of Computing and Communications Center, Kyushu University, Fukuoka, Japan.
3. Department of Surgery, Seoul National University Bundang Hospital, Seongnam, Korea.
4. Department of Surgery and Oncology, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan.