1. Department of Biomedical Engineering, Seoul National University College of Medicine, Seoul, Korea.
2. Department of Rehabilitation Medicine, Seoul National University College of Medicine, Seoul, Korea.
3. Interdisciplinary Program for Bioengineering, Seoul National University Graduate School, Seoul, Korea.
4. Department of Physical Medicine and Rehabilitation, Chung-Ang University College of Medicine, Seoul, Korea.
5. Department of Medical and Biological Engineering, Kyungpook National University, Daegu, Korea.
6. Department of Rehabilitation Medicine, National Medical Center, Seoul, Korea.
7. Institute of Medical and Biological Engineering, Seoul National University, Seoul, Korea.