Development of a neuroprosthesis for restoring arm and hand function via functional electrical stimulation following high cervical spinal cord injury.

This paper describes the development of an implanted neuroprosthesis for restoring hand and arm function to individuals with high level tetraplegia resulting from C1-C4 spinal cord injury. These individuals have complete paralysis below the level of the neck and are thus highly disabled. The neuroprosthesis under development will restore basic upper extremity movements needed for simple yet important daily activities such as eating and grooming. Simulations performed with a musculoskeletal model of the shoulder and elbow indicate that existing stimulation technology using a realistic number of stimulation channels should be sufficient for providing these functions. The neuroprosthesis will utilize 24 channels of stimulation, muscle-based electrodes for stimulation of hand muscles, and nerve cuff electrodes for stimulation of shoulder and elbow muscles. The two implanted stimulators also include a total of four implanted bipolar EMG recording channels that sample activity in neck and facial muscles. These signals, along with measurements of head orientation, will provide the user command interface for this system.