1. Division of Pediatric Surgery Department of Surgery Kobe University Graduate School of Medicine Kobe Japan
2. Department of Pediatric Surgery Kobe Children's Hospital Kobe Japan
3. Department of Pediatric Surgery Kyusyu University Fukuoka Japan
4. Department of Mechanical Engineering Faculty of Engineering Science Kansai University Suita Japan
5. Division of Hepato‐Biliary‐Pancreatic Surgery Department of Surgery Kobe University Graduate School of Medicine Kobe Japan