1. Department of Rehabilitation Medicine, University of Minnesota School of Medicine, Minneapolis, Minnesota, USA.
2. Department of Neurological Surgery, Swedish Medical Center, Englewood, Colorado, USA.
3. Department of Diagnostics and Biological Sciences, University of Minnesota School of Dentistry, Minneapolis, Minnesota, USA.
4. Department of Physical Medicine and Rehabilitation, Harvard Medical School, Spaulding Rehabilitation Hospital, Charlestown, Massachusetts, USA.
5. Department of Biomedical Engineering, Worcester Polytechnic Institute, Worcester, Massachusetts, USA.