Noise Reduction of Electrocardiographic Signals using Wavelet Transforms

It has always been a critical issue to extract original signal having low signal-to-noise ratio (SNR) buried in heavy noise and interferences. Since the amplitude of the electrocardiogram (ECG) signal is smaller so while gathering and recording it may mix with various kinds of noises and interferences. In this paper, wavelet thresholding de-noising method based on stationary wavelet transform (SWT) is proposed in de-noising of ECG signal. In addition, this paper compares various de-noising methods to validate the proposed de-noising method. The improved de-noising method ensures that the geometrical characteristics of the original ECG are retained as well as efficiently suppresses additive noises. The experimental results reveal that the SWT method is better than traditional wavelet de-noising methods to maintain original shape of ECG waveform having improved SNR.