POWER LINE NOISE REDUCTION IN ECG BY BUTTERWORTH NOTCH FILTERS: A COMPARATIVE STUDY

Background: The electrocardiogram has the considerable diagnostic significance, and applications of ECG monitoring are diverse and in wide use. Noises that commonly disturb the basic electrocardiogram are power line interference, instrumentation noise, external electromagnetic field interference, noise due to random body movements and respiration movements. These noises can be classified according to their frequency content. It is essential to reduce these disturbances in ECG signal to improve accuracy and reliability. The bandwidth of the noise overlaps that of wanted signals, so that simple filtering cannot sufficiently enhance the signal to noise ratio. The present paper deals with the digital filtering method to reduce 50 Hz power line noise artifacts in the ECG signal. 4th order Butterworth notch filters with different 3 dB stop band bandwidth is used to reduce 50 Hz power line noise interference from ECG signals.