QRS detection based on wavelet coefficients

► We make QRS detection using a single threshold obtained from wavelet coefficients. ► Power spectrum in different energy levels is used to calculate detector threshold. ► QRS energy is highest in the range (11.25-22.5 Hz) for normal beats. ► QRS energy is highest in the range (6.62-11.25 Hz) for ventricular extra-systoles. ► Effect of artifacts, T and P waves are attenuated using wavelet detail coefficients.