Integrated EEG Acquisition System for MRI Electromagnetic Environment Applications

Abstract

From detail analysis on origins of artifacts which influences EEG signal quality and compared with traditional simultaneous MRI/EEG acquiring system [3], an in-bore MRI electromagnetic environment compatible EEG signal acquiring system on chip was proposed, with the key module: preamplifier implemented in 0.18um technology and simulated in Cadence. This thesis presents the design procedure and simulation results of the preamplifier. As result, an AC coupling chopper stabilized INA with second stage low pass filter is present. Simulation results shown it has desired differential gain and Common Mode Rejection Ratio (CMRR) ideal for amplifying the weak biopotential while rejecting the stronger common mode interferers. Noise performance is greatly improved with the application of chopper stabilization technique which moves signal frequency band out of 1/f noise dominant frequency band before amplification.