A Wireless Implantable Microsystem for Multichannel Neural Recording

Abstract

An implantable microsystem capable of recording neural activity simultaneously on 64 channels is reported. This system receives power and setup data through an inductive wireless link, and wirelessly transmits the recorded neural information to an external interface. The microsystem is capable of detecting spike occurrences, as well as digitizing 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 muV <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/s using a 2-MHz clock. The system dissipates 14.4 mW at 1.8 V, weighs 275 mg, and measures 1.4 cm times 1.55 cm.