1. Department of Mechanical Engineering, Yonsei University, Seoul, South Korea
2. Department of Orthopaedic Surgery, Yonsei Sarang Hospital, Seoul, South Korea
3. Department of Orthopaedic Surgery, The Bone Hospital, Seoul, South Korea
4. Department of Anesthesiology & Pain Medicine, Hallym University College of Medicine and Kangdong Sacred Heart Hospital, Seoul, South Korea