Design of a Low-Noise Amplifier for Nerve Cuff Electrode Recording

Abstract

A low–noise amplifier was developed for recording peripheral nerve signals with cuff electrodes. The output was amplified with a gain of 10000 and bandpass filtered from 300 to 5000 Hz. The total noise of the amplifier was below 1 microvolt RMS for a cuff impedance of 1 kΩ, and the common-mode rejection ratio was 107 dB at 1 kHz. To maximize the amplitudes of the nerve signals in the limited implant site, the cuff electrode was fabricated as long as possible with the dimension of the inner diameter of 1 mm and the length of 10 mm. The cuff electrode was then assembled together with closure, pre-amplifier circuits and headstage connector. In experiments, the performance was evaluated in vivo on the sciatic nerve in a rat animal model.