An 8-Channel Ambulatory EEG Recording IC with In-Channel Fully-Analog
Real-Time Motion Artifact Extraction and Removal
Abstract
Abstract—We report the design, implementation, and experimental
characterization of an 8-channel EEG recording IC (0.13μm CMOS, 12mm2
total area) with a channel architecture that conducts both the
extraction and removal of motion artifacts on-chip and in-channel. The
proposed dual-path feed-forward method for artifact extraction and
removal is implemented in the analog domain, hence is needless of a DSP
unit for artifact estimation, and its associated high-DR ADCs and DACs
employed by the state of the art for artifact replica generation.
Additionally, the presented architecture improves system’s scalability
as it enables channels’ stand-alone operation, and yields the lowest
reported channel power consumption among works featuring motion artifact
detection/removal.
Following an experimental study on electrode-skin interface electrical
characteristics for dry electrodes in the absence and presence of
motions, the paper presents the channel architecture, its detailed
signal transfer function analysis, circuitlevel implementation, and
experimental characterization results. Our measurement results show an
amplification voltage gain of 48.3dB, a bandwidth of 300Hz, rail-to-rail
input DC offset tolerance, and 41.5dB artifact suppression, while
consuming 55μW per channel. The system’s efficacy in EEG motion artifact
suppression is validated experimentally, and system-and circuitlevel
features and performance metrics of the presented design are compared
with the state of the art.