  This paper presents a low power ECG recording Sys-tem-on-Chip (SoC) with
on-chip low complexity lossless ECG compression for data reduction in
wireless/ambulatory ECG sensor devices. The proposed algorithm uses a linear
slope predictor to estimate the ECG samples, and uses a novel low complexity
dynamic coding-packaging scheme to frame the resulting estimation 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 0.35 {\mu}m
process, the compressor uses 0.565 K gates/channel occupying 0.4 mm2 for
4-channel, and consumes 535 nW/channel at 2.4V for ECG sampled at 512 Hz. Small
size and ultra-low power consumption makes the proposed technique suitable for
wearable ECG sensor application.
