Abstract: An Electro Cardiogram is the observation and recording of electrical information in the heart. Technological developments in the medical industry and non-aggressive monitoring of critical biological functions is an important need to provide appropriate care to patients and leads to their improved health. ECG signal analysis has been in use for a long time for cardiac problems. Technological advancements made the ECG observation quite easy but quite often, they get corrupted by different type of noises. Hence De-noising of ECG signal has gained a lot of importance. This paper deals with de-noising of three majorly encountered ECG disturbances viz. Power Line Interference, Wide Band Stochastic noise (EMG noise) and Base Line Wander noise. The De-noising is performed using various wavelet Transform techniques applying different types of threshold functions. Performance is measured using SNR and MSE and optimized combinations of Wavelet with a Threshold functions for different noises are suggested. The analysis is also done on real ECG signals obtained from Physionet medical database.
Keywords: Electro Cardiogram (ECG), Power Line interference, Electromyography (EMG) noise, Base line wander noise, Wavelet Transform, Signal to Noise ratio (SNR), Mean Square Error (MSE), Physionet.