ECG-noise Removal from EMG-signal by Subtraction of Hybrid Template of Averaged PQRS- T Intervals

Abstract

The frequency domains of the ECG and EMG signals overlap, making it difficult to filter the ECG noise without distortion of the EMG signal. A method of EMG denoising by subtraction of averaged P-QRS-T interval is known in the literature. The proper functioning of the method depends on how the template is formed. Several ways of forming ECG-template have been tested in the current study, and has been proven that the ’hybrid’ is the best i.e. high-frequency components, as QRS, are taken from the unfiltered EMG + ECG, while the low-frequency – from the averaged siagnal. The good performance of the hybrid method is proven by almost complete identity of initial and processed EMG, when compared by fast Fourier transform (FFT). The presence of ectopic beats in the averaged ECG-template worsens the performance and a way to overcome the problem is proposed