MAC based FIR filter: A novel approach for low-power real-time de-noising of ECG signals

Wearable real-time Electrocardiogram (ECG) monitoring is an emerging wireless technology enabling early diagnosis and increased ability of prevention of cardiovascular diseases. However, the ECG signal suffers from Powerline Interference (PLI) which corrupts the biomedical recordings. Low power and high speed filtering of the ECG signal is essential to make the monitoring device portable. This paper proposes an FIR (Finite Impulse Response) filter based on Multiply-Accumulator (MAC) Unit to suppress the PLI noise. The performance of this filter largely depends on the speed and power of the MAC unit employed inside the filter. The current work compares various MAC units on Power, Performance and Area (PPA) benchmarks. It is shown that Booth-Wallace-Carry Look Ahead adder(CLA) based MAC is optimised for both timing and power which shows 6.2% improvement in performance and 12.1% reduction in power from other implemented designs. Thus, the real-time low power FIR filter is realised using Booth-Wallace-CLA MAC. The convergence time of the algorithm is observed to be less than 0.2 μsec with significant power savings to improve battery life.