Spinal Cord Stimulation for Functional Closed-Loop Experiments

SCS leads were implanted through a minimally invasive, outpatient procedure performed under local anesthesia, described previously^{25 (link)}. Briefly, three 16-contact SCS leads (Infinion, Boston Scientific) were inserted percutaneously into the epidural space on the lateral aspect of the C5–C8 spinal cord. Contacts were 3 mm long, with 1 mm inter-contact spacing. Lead placement was iteratively adjusted based on the subjects’ verbal report of the location of sensations evoked by intraoperative stimulation. The leads were implanted for fewer than 29 days. Subjects attended testing sessions 3–4 days per week during the implantation period. For each subject, the majority of implant time was used to characterize perceptual characteristics of the evoked sensations^{25 (link)}. The functional closed-loop experiments described here were performed during the last 5 days of the study.