Removal of Narrowband Interference (PLI in ECG Signal) Using Ramanujan Periodic Transform (RPT)

TL;DR

This paper introduces a novel method using Ramanujan periodic transform to effectively suppress powerline interference in ECG signals, demonstrating significant error reduction with increased transform length.

Contribution

The work presents the first application of Ramanujan periodic transform for PLI suppression in ECG signals, showing improved performance over traditional notch filters.

Findings

Error decreases by 50% with doubling N in RPT.

RPT outperforms notch filter in PLI suppression.

Transform length N impacts suppression effectiveness.

Abstract

Suppression of interference from narrowband frequency signals play vital role in many signal processing and communication applications. A transform based method for suppression of narrow band interference in a biomedical signal is proposed. As a specific example Electrocardiogram (ECG) is considered for the analysis. ECG is one of the widely used biomedical signal. ECG signal is often contaminated with baseline wander noise, powerline interference (PLI) and artifacts (bioelectric signals), which complicates the processing of raw ECG signal. This work proposes an approach using Ramanujan periodic transform for reducing PLI and is tested on a subject data from MIT-BIH Arrhythmia database. A sum ($E$) of Euclidean error per block ($e_i$) is used as measure to quantify the suppression capability of RPT and notch filter based methods. The transformation is performed for different lengths ($N$), namely $36$, $72$, $108$, $144$, $180$. Every doubling of $N$-points results in $50{\%}$ reduction in error ($E$).