Nonlocal Means Denoising of ECG Signals

Patch-based methods have attracted significant attention in recent years within the field of image processing for a variety of problems including denoising, inpainting, and super-resolution interpolation. Despite their prevalence for processing 2-D signals, they have received little attention in the 1-D signal processing literature. In this letter, we explore application of one such method, the nonlocal means (NLM) approach, to the denoising of biomedical signals. Using ECG as an example, we demonstrate that a straightforward NLM-based denoising scheme provides signal-to-noise ratio improvements very similar to state of the art wavelet-based methods, while giving <formula formulatype="inline"><tex Notation="TeX">$\sim$</tex></formula>3<formula formulatype="inline"><tex Notation="TeX">$\times$</tex></formula> or greater reduction in metrics measuring distortion of the denoised waveform.