1. Department of Neurosurgery, University of Iowa Hospitals and Clinics, Iowa City, Iowa
2. Department of Anesthesia, University of Iowa Hospitals and Clinics, Iowa City, Iowa
3. Department of Urology, University of Iowa Hospitals and Clinics, Iowa City, Iowa
4. Department of Neurosurgery, University of Louisville, Louisville, Kentucky
5. Center for Neurological Restoration, Cleveland Clinic, Cleveland, Ohio, USA
6. Department of Neurosurgery, Hospital Marcelino Champagnat, Curitiba, PR, Brazil
7. Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, Virginia, USA