Nerve Cuff Electrodes for Prosthetic and Research Applications

A new generation of nerve cuffs suitable for stimulation, recording and modulation of nerve activity has been tested in our laboratory and elsewhere. The walls are molded of low-durometer silicone and incorporate flexible electrodes, Teflon-coated stainless steel leads and an interlocking opening/closing system. Stimulation and recording cuffs can be either single-channel or multichannel. Single-channel cuffs have coiled circumferential electrodes. Multi-channel cuffs have internal chambers and up to 24 laser-positioned electrodes. Modulation cuffs include catheters for local delivery of pharmacological agents. The cuffs are produced and distributed by NeuroStream Technologies, Anmore, B.C., Canada. Over 100 single-channel, 30 multi-channel and 20 modulation cuff prototypes have been implanted in laboratory animals, typically for 6 months. Electrode impedances and nerve compound action potentials were periodically monitored. Individual electrodes in multi-channel cuffs could selectively recruit different limb muscles and record distinct cutaneous fields. A morphological study of nerves inside cuffs indicated no loss of axons and only small changes in axon diameters and myelin thickness. NeuroStream cuffs are now available for testing in a variety of intended clinical FES applications.