1. Department of Neurosurgery, University of Maryland School of Medicine, 10 South Pine Street, Medical School Teaching Facility 559 A, Baltimore, MD 21201, USA
2. Department of Biomedical Engineering, Physical Medicine & Rehabilitation, Anesthesiology & Critical Care Medicine, Johns Hopkins University, Baltimore, MD 21205, USA
3. Department of Bioengineering, The University of Texas at Dallas, Richardson, TX, USA
4. Surgery Department, University of Texas Southwestern Medical Center, TX, USA
5. Departments of Neurosurgery and Physical Medicine & Rehabilitation, Harvard Medical School, Brigham and Women’s Hospital, Spaulding Rehabilitation Hospital and VA Boston Healthcare System, Boston, MA, USA