QRS waves detection algorithm based on positive-negative adaptive threshold method

In order to accurately detect the occasional negative R waves in electrocardiography (ECG) signals, the positive-negative adaptive threshold method is adopted to determine the positive R waves and the negative R waves, according to difference characteristics of ECG signals. The Q and S waves can then be accurately positioned based on the basic characteristics of QRS waves. Finally, the algorithm simulation is made based on the signals from MIT-BIH database with MATLAB. The experimental results show that the algorithm can improve the detection accuracy rate to 99.91% and overcome the problem of larger computation load for wavelet transform and other methods, so the algorithm is suitable for real-time detection.