The electrocardiogram is generally used clinically in diagnosing the heart diseases. Hence, it must
be very accurate. Signals recorded are often contaminated with Power Lime 50 Hz noise and
harmonics originating from power supplies, power mains and lights. The presence of noise cormpts
the information content of these signals and can degrade the quality of subsequent data analysis.
This electrical interference is notoriously difficult to remove without altering the original signal
imbedded within the noise. The power line interference reduction in ECG records is a challenging
problem which is still open for research. The power line signal, measured directly &om the
transmission lie may have amplitude, phase and frequency variations. This paper deals with
designing 50 Hz Twin-T notch filter for elimmating the power line noise from ECG signa