1. Division of Cardiology, Severance Cardiovascular Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
2. Severance Biomedical Science Institute, College of Medicine, Yonsei University, Seoul, Republic of Korea
3. Department of Obstetrics and Gynecology, Yonsei University College of Medicine, Seoul, Republic of Korea
4. Department of Orthopaedic Surgery, Yonsei University College of Medicine, Seoul 120-752, Republic of Korea
5. Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea
6. Department of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, USA