External pressure measurements for nerve cuff electrodes

Abstract

When large external pressures are applied to a peripheral nerve, tissue damage can occur via compression and blood flow occlusion, resulting in degeneration and demyelination of axons. This tissue damage must be avoided when implementing nerve cuff electrodes for electrical stimulation of axons. However, post-implant nerve swelling can result in these cuffs exerting large pressures. Currently, only theoretical models are used to predict nerve cuff electrode pressures. The goals of this investigation are (1) to develop a technique to measure external pressures applied by cuff electrodes, (2) to compare experimentally determined cuff pressures with those predicted by theoretical models, and (3) to quantitatively compare different cuff electrodes using a cuff pressure versus nerve diameter relationship. This report describes a pressure measurement technique designed for cuff electrodes and presents some preliminary measurements for various cuff designs.