A 457-nW cognitive multi-functional ECG processor

In this paper, a multi-functional ECG signal processor for wearable and implantable real-time monitoring is presented. To enable extremely long-term ambulatory monitoring, several power saving techniques are proposed, including global cognitive clocking, pseudo-downsampling wavelet transform, adaptive storing, and denoising-based run-length compression. An on-chip low-complexity cardiac signal analysis module is proposed to realize comprehensive analysis functions. Near-threshold circuit technique is applied to the overall system. Implemented in 0.18 μm CMOS, the proposed cognitive ECG processor consumes only 457 nW at 0.5 V supply for real-time ambulatory monitoring. Compared with existing designs, the presented ECG processor achieves the lowest power consumption.