Impedance Monitoring for Nerve Regeneration Using an Implantable Cuff

A miniaturized discrete system to measure impedance for long term monitoring of peripheral nerve regeneration after injury, has been developed in this work. The device uses programmable sinusoidal currents that are injected into tissue and resulting potentials developed are measured to calculate the impedance of the nerve. It features a single current source and two single pole triple throw switches for measuring between any pair of 4 electrodes. In addition, a procedure for developing a polydimethylsiloxane (PDMS) cuff to embed platinum ring electrodes and eventually electronics is also presented. Devices were tested in saline solutions, acute experiments with in vivo and resected nerves, and in a 3-week in vivo implant experiment in rats. Developing a novel method to monitor nerve regeneration while reducing the number of surgeries is a desirable way to improve and track outcomes of repair and rehabilitation of injured nerves.