This project seeks to develop a multi-channel nerve cuff with on board wireless control for stimulating specific bundles of fibers within trunk nerves. Clinical applications include: 1) Stimulating the sensory nerves in the residual limbs of amputees to provide touch sensations from their prosthetic arms. By activating specific components of the median nerve, it will be possible to induce sensations that appear to the amputee to emanate from specific regions of the fingers and hand. By providing input from each of the contacting fingers at the same time, a prosthesis user will be able to know which fingers are in contact with a grasp object and how the forces are distributed. Additionally, electrical activation of amputated sensory nerves has been demonstrated to allow amputees to consider their prosthesis to be more a part of their body, and such electrical stimulation has been shown to be useful for preventing or managing phantom limb pain. 2) Muscle ? stimulation systems that restore hand function or standing and walking in cases of spinal cord injury and stroke. The use of multi-channel cuffs that don't require attached lead wires can reduce the surgery needed to implant stimulation hardware and eliminate the need to implant separate electrodes into each muscle in these systems, and it will offer improved muscle controllability. 3) The multi-channel cuff would also be useful for optic nerve stimulation for artificial vision. The cuff that will be developed uses a self-coiling design made from thin silicone sheeting laminated around a separate lattice structure containing the electrode contacts and interconnect traces. The lattice is made from Liquid Crystal Polymer sheeting (LCP) which has ideal properties for implanted electronic devices: including low tissue reactivity; high resistance to stretching, tearing and breakage from repeated bending; and the ability to be micro-machined to form arbitrary patterns. ? ? Electronic components and interconnects are easily mounted on LCP, and a vapor tight package can be formed by welding an LCP 'cap' to the substrate. This packaging advantage of using LCP enables the stimulation and wire-less control circuitry to be located directly on the cuff. The PHASE 1 project includes initial bench testing of the cuffs and the integral electronics and packaging methods. PHASE II work will involve in-vivo tests in animal models followed by evaluation in clinical trials with amputee volunteers and with spinal cord injury and stroke patients. ? ?
