1. Pratt School of Engineering, Duke University, Durham, North Carolina, USA
2. School of Medicine, Duke University, Durham, North Carolina, USA
3. Department of Neurosurgery, Duke University Hospital, Durham, North Carolina, USA
4. Department of Orthopeadics, Duke University Medical Center, Durham, North Carolina, USA
5. Duke Cancer Institute, Duke University Medical Center, Durham, North Carolina, USA
6. Department of Surgery, Duke University Medical Center, Durham, North Carolina, USA