Clinical implementation of nerve cuff electrodes for an upper extremity neuroprosthesis

Functional electrical stimulation (FES) is used to elicit contractions in paralyzed muscles and increase the independence of people with impaired neurological function. Most existing neuroprostheses consists of muscle-based electrodes. However, nerve electrodes are emerging as a tool to provide increased benefit for increasingly complicated systems. Many types of nerve electrodes have been developed and tested in animals but few have been transferred to clinical use and none have been used in motor neuroprostheses. This work has set up and followed a strategy to overcome the obstacles to clinical deployment for the spiral nerve cuff electrode.; Initial intraoperative testing provided valuable information about the function of human nerves. Stimulation thresholds were determined to be similar to the animal studies and selective activation of a single muscle was possible from all nerves. This information was used to choose electrode locations and stimulation parameters for chronic testing.; Chronically implanted spiral nerve cuff electrodes were found to be a stable platform for activation of paralyzed muscles. There were no adverse functional changes or sensation due to the implanted electrodes implanted for over 1.5 years. Nerve stimulation produced controllable activation of the distal muscles with joint moments sufficient for functional tasks. At least one muscle could be selectively activated form each proximal nerve trunk and the selectivity increased with the use of multi-contact stimulation.; The spiral nerve cuff electrode is an effective tool for activating paralyzed muscles in the human extremities.