  This paper presents a low-power ECG recording system-on-chip (SoC) with
on-chip low-complexity lossless ECG compression for data reduction in
wireless/ambulatory ECG sensor devices. The chip uses a linear slope predictor
for data compression, and incorporates a novel low-complexity dynamic
coding-packaging scheme to frame the prediction error into fixed-length 16-bit
format. The proposed technique achieves an average compression ratio of 2.25x
on MIT/BIH ECG database. Implemented in a standard 0.35 um process, the
compressor uses 0.565K gates/channel occupying 0.4 mm2 for four channels, and
consumes 535 nW/channel at 2.4 V for ECG sampled at 512 Hz. Small size and
ultra-low power consumption makes the proposed technique suitable for wearable
ECG sensor applications.
