ECG Denoising and Power-line Interference Rejection by Local Quadratic Variation Reduction

The ECG is the standard noninvasive test used to measure the electrical activity of heart. Unfortunately ECG signals are corrupted by several kinds of noise and artifacts, such as power-line interference, that may negatively affect any subsequent analysis. We have recently proposed a novel algorithm for denoising ECG signals, based on the notion of quadratic variation reduction. The algorithm proved to be quite good in denoising ECG records affected by noise, but its effectiveness reduces when it is used in filtering out power-line interference. In this paper, we propose an algorithm that overcomes this limitation and extends our approach allowing it to both denoise and reject power-line interference. Simulation results confirm the effectiveness of the approach and highlight a notable ability to remove both noise and power-line interference in ECG signals.