Low-power and Low-noise Amplifier with Intermittent Operation for Compressed Sensing in EEG Measurement Systems

This study presents a solution to achieve low power consumption by the intermittent operation of low-noise amplifiers (LNAs) for wireless electroencephalographs, that need a smaller battery. The LNA operates intermittently synchronized with the sampling timing of the analog-to-digital converter (ADC) by using the random undersampling matrix utilized in a previously proposed compressed sensing (CS) electroencephalogram measurement system. Designed using a 0.18 μm CMOS process, the LNA includes an intermittent operation circuit. The simulation results, the start-up time of the LNA was set to 4ms and the intermittent operation was performed at compression ratio of 4.17 based on a sampling frequency of 200Hz. The intermittent operation reduced power consumption by 58% compared to constant operation. The normalized mean square error (NMSE) was used to evaluate the influence of intermittent LNA operation on the reconstruction accuracy of CS. The difference in NMSE between intermittent and constant operation was only 9% on average over 25 frames. This indicates that intermittent operation minimally influenced the reconstruction accuracy.