1. National Defense Medical College, Research Institute, Division of Biomedical Engineering, 3‐2 Namiki, Tokorozawa, Saitama 359‐8513, Japan
2. National Defense Medical College, Department of Orthopedic Surgery, 3‐2 Namiki, Tokorozawa, Saitama 359‐8513, Japan
3. NeTech Incorporated, KSP East Wing 502, Sakado 3‐2‐1, Takatsu, Kawasaki, Kanagawa 213‐0012, Japan
4. National Defense Medical College, Department of Surgery II, 3‐2 Namiki, Tokorozawa, Saitama 359‐8513, Japan
5. National Defense Medical College, Department of Medical Engineering, 3‐2 Namiki, Tokorozawa, Saitama 359‐8513, Japan