BRIEF COMMUNICATION A Miniaturized Cuff Electrode for Electrical Stimulation of Peripheral Nerves in the Freely Moving Rat

ABSTRACT: A bipolar cuff electrode for electrical stimulation of ma i l diameter peripheral nerves is described. The cuff is made of a highly flexible rubber-impression material, and the electrode assembly is suited for chronic implantation. Its manual con-struction is easy and reliable, utilizing only simple tools. The cuff completely envelopes nerves of varying diameter and requires a minimal amount of manipulations of the nerve, therel)y reducing the chance of surgical trauma. The snug envelope prevents the nerve from drying, and minimizes shunting between the two leads by exl~cellular fluids. Small outer dimensions were achieved: 1.4 × 1.1 × 2.3 mm (width × height × length) when used with nerves of I mm diameter, which minimizes pressure and damage to surrounding tissues. Morphomel~c analysis of nerves enclosed in cuffs for 28-30 h revealed a small decrease in the number of large-diameter fibers. SUmulation thresholds remained, however, constant throughout the experiments