A 32-Channel Low-Power Neural Recording System with Continuously Monitoring for ECoG Signal Detection

Abstract

In this study, a 32-channel low-power neural recording system was developed to analyze neural activity. Neural activity recording systems play an important role in neurosciences as well as the development of neuroprosthetic devices to treat neurological diseases and assist in recovery from disabilities. For example, monitoring neural signals allows prediction of the behaviors of paralyzed patients or explanation for the causality between behavior and neural activity. A conventional recording system with an integrated circuit has several limitations in terms of noise and power consumption. Herein, we propose a 32-channel low-power fully implantable neural signal recording system; a low-noise amplifier, a lowpass filter, an analog multiplexer, and a shift register were designed for the system. The experimental results highlight the low noise and adequate frequency response of the system. Further, in the experiments, ECG signals with magnitudes of up to 100 μV could be detected clearly. For the 32-channel neural recording system, a low supply voltage of only 1.2 V is needed, and the total power consumption is 60 μW, with a total gain of 58 dB and input referred noise of 3 μVrms. The bandwidth of the system is 2–300 Hz for measuring target ECoG signals. The system was designed with a standard 0.18 μm CMOS technology to measure neural signals while maintaining very low power consumption.