Function-inspection scheme for an injured peripheral nerve using a polymer based microelectrode array

摘要

This paper presents a compound nerve action potential (CNAP) monitoring system of a peripheral nerve which is composed of a sieve-shape flexible microelectrode array (MEA), a polyglycolic acid (PGA) conduit and a bio-potential amplifier. The system observes a regenerated peripheral nerve by measuring its CNAP An MEA is fabricated through micromachining technology, and its interfacial impedance (420 k Omega/mu m(2)) and signal transfer characteristics were analyzed. The fabricated MEA was assembled with the PGA conduit, and then the assembly had been implanted into a sciatic nerve of a rat. After 12 week-implantation periods, regenerated state of the damaged sciatic nerve was investigated by gait analysis and CNAP measurement. From the gait analysis, sciatic function index (SFI) was calculated to be -48.5 +/- 15.0. According to the CNAP measurement, threshold potential was 250 mu V in contrast to 110 mu V for a normal nerve. After the functional tests, regenerated nerves were harvested and their morphologies were examined through toluidine blue (TB), Hematoxylin and Eosin (H&E) and transmission electron microscope (TEM) images. According to the morphology study, it was confirmed that proximal and distal nerve stump showed similar morphology and axon number. (c) 2007 Elsevier B.V. All rights reserved.