Elimination of Power Line Interference in ECG Signal Using Adaptive Filter, Notch Filter and Discrete Wavelet Transform Techniques

An ECG is a biomedical non-stationary signal, which contains valuable information about the electrical activity of the heart. The ECG is very sensitive and a weak signal, hence, it gets corrupted by various types of noise such as power line interference, baseline wander, motion artifacts, muscle contractions, electrode contact noise, etc., that may lead to a misdiagnosis. Among these noise parameters the power line interference is very crucial because noise falls in the ECG bandwidth, i.e. 0.05 Hz to 100 Hz. The article proposes the removal of power line interference (PLI) noise in an ECG signal based on discrete wavelet transform (DWT) and adaptive filtering techniques. The results are compared with the existing notch filter both in time and frequency domain by filter performance parameters like ESD, MSE %PSD and SNR.