Designing and Implementation of Digital Filter for Power line Interference Suppression

This paper presents removal of noise from the ECG signal by using Digital filters designed with FIR and IIR technique. The analysis of ECG signal has great importance in the detection of cardiac abnormalities. The ECG signal is preserve of the electrical performance of heart versus time. ECG signal of a normal heart beat consists of a three parts P wave, QRS complex and T wave. The P wave reflects the activation of the right and left atria. The QRS complex shows depolarization of the activation of right and left ventricles. Results are obtained for the given order of the filter using windowing technique for the FIR filter. Powerline interference corrupts biomedical recordings. A Digital filter is one of the filters that are suggested to suppress the fundamental powerline interference and its harmonics in electrocardiographic recordings. The aim of this paper is to design and implement digital filter for suppressing the 50Hz powerline interference, with Different window function in electrocardiographic (ECG) signal recordings. The wavelet transform is used to reduce the effect of noise to get refined signal. The power spectral density and average power, before and after filtereration using different window techniques and wavelet utilization at 4 and 6 dB are compared. Order of the filter is also different. Filter with the Kaiser window shows the best result. Index Term— ECG, FIR Filter, Windowing Technique, Wavelet Transform, power spectral density and average power