Application of a Reduced Band-pass Filter in the Extraction of Power-line Interference from ECG Signals

The paper proposes a digital band-pass filter designed to extract power-line interferences from ECG signals. The filter is called “reduced” because it processes samples that are distanced in a quarter of power-line period. During the extraction of the interference, an assessment of power-line frequency is performed and an appropriate adaptation of the coefficients of the reduced filter is performed. The reduced band-pass filter is suitable for mains interference rejection, as well as for its frequency measuring.