Abstract: Filtering of power line interference is very meaningful in the measurement of biomedical events recording, particularly in the case of recording signals as weak as the ECG signal. ECG is a biomedical signal which gives electrical activity of heart. This ECG signal is corrupted by various noises like power line interference, baseline wandering, channel noise, contact noise, muscle artifacts etc. Frequency range of ECG signal is nearly same as the frequency of power line interference. ECG signal has frequency range from 0.5 Hz to 80 Hz and power line interference introduces 50 to 60 Hz frequency component in that signal which is the major cause of corruption of ECG. From various artifacts contaminate electrocardiogram (ECG) recording, the most common are power line interference. Power line interference is not easily recognizable since the interfering voltage in the ECG may have frequency 50 Hz. The most common cause of 50 Hz interference is the disconnected electrode resulting in a very strong disturbing signal, and therefore needs quick action. Electromagnetic interference from the power lines also results in poor quality tracings. Electrical equipment’s such as air conditioner, elevators and X-ray units draw heavy power line current, which induce 50 Hz signals in the input circuits of the ECG machine. This project focuses on a technique for de noising of such non stationary ECG signal using adaptive filter algorithms like LMS, NLMS, RLS and compares their performance characteristics using MATLAB.
Keywords: ECG, LMS, NLMS, RLS, MATLAB, Power Line Interference.