1. Bloorview Research Institute; Holland Bloorview Kids Rehabilitation Hospital; Toronto Ontario Canada
2. Institute of Biomaterials and Biomedical Engineering; University of Toronto; Toronto Ontario Canada
3. Department of Electrical and Electronic Engineering; Yonsei University; 262 Seongsanno, Seodaemun-gu Seoul 120-749 Korea
4. School of Materials Science and Engineering and Department of Nanobio Materials and Electronics; Gwangju Institute of Science and Technology; 123 Chemdan-gwagiro, Buk-gu Gwangju 500-712 Korea
5. Department of Industrial and Systems Engineering, Rutgers Center for Operations Research, Rutgers; The State University of New Jersey; Piscataway NJ 08854 USA
6. Department of Industrial and Information Engineering; University of Tennessee; Knoxville TN 37996 USA
7. Department of Materials Science and Engineering; Yonsei University; 262 Seongsanno, Seodaemun-gu Seoul 120-749 Korea