An Implantable 64-Channel Wireless Microsystem for Single-Unit Neural Recording

Abstract

This paper reports an implantable microsystem capable of recording neural activity simultaneously on 64 channels, wirelessly transmitting spike occurrences to an external interface. The microsystem also allows the user to examine the spike waveforms on any channel with 8 bit resolution. Signals are amplified by 60 dB with a programmable bandwidth from < 100 Hz to 10 kHz. The input-referred noise is 8 ¿V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">rms</sub> . The channel scan rate for spike detection is 62.5 kS/sec using a 2 MHz clock. The system dissipates 14.4 mW at 1.8 V, weighs 275 mg, and measures 1.4 cm 1.55 cm.