Power Line Interference Removal from ECG Signal using Adaptive and Error Filter

An Electrocardiogram (ECG) signal is electric representation of the activity of human’s heart. It is needed to detect the health issues related to heart disease. But sometimes due to mismatches in electrodes signal becomes noisy [2]. Noisy ECG signal may cause difficulty in diagnosis of disease, since very fine features present in an ECG signal may convey important information. So to avoid this, it is important to have the signal as clean as possible. ECG signals may become noisy by power line. The major difficulty in removing this power line interference is that the frequency can vary about fractions of a Hertz, or even a few Hertz. For this use of notch filter to eliminate only the undesirable power line interference while automatically adapting itself to variations in the frequency and level of the noise is one of the best solutions [1]. Proposed method uses the adaptive least mean square (LMS) algorithm for updating the coefficient of notch filter. A method for adaptive notch filter to eliminate power line interference from ECG signal's output is then passes through error filter for achieving the best result. This method can be used in the medical equipments to remove noise caused due to AC supply.