Delineation of the QRS complex using the envelope of the e.c.g.

A new algorithm for QRS delineation has been developed. Based on the envelope of the e.c.g. signal a delineation function is defined, which yields a single positive pulse for each complex. From this function the onset and end of the QRS or, alternatively, a fiducial point is determined. To remove low-frequency component such as S-T abnormalities without distortion of the QRS complex, a filter with time-varying characteristics is used. The accuracy of the method has been evaluated in a test set of different QRS complexes obtained from coronary care patients. For QRS onset, the standard deviation of the difference between automated and manual determination was 7 ms in normal beats and 14 ms in ectopic beats. With simulated noise added to each waveform an average dispersion of 7 ms was observed in the recognition of the QRS onset at a signal-to-noise ratio of 15 dB. The corresponding dispersion in the location of a fiducial point was 2 ms. Using simulated e.c.g. data, the stability of the method is demonstrated for transitions between different waveform morphologies.

[1]  B. Ripley,et al.  Pattern Recognition , 1968, Nature.

[2]  P G Amazeen,et al.  Phase detection of R waves in noisy electrocardiograms. , 1972, IEEE transactions on bio-medical engineering.

[3]  J L Talmon,et al.  Template waveform recognition applied to ECG-VCG analysis. , 1973, Computers and biomedical research, an international journal.

[4]  L. Rabiner,et al.  A computer program for designing optimum FIR linear phase digital filters , 1973 .

[5]  J H van Bemmel,et al.  Pattern recognition for ECG-monitoring: an interactive method for the classification of ventricular complexes. , 1973, Computers and biomedical research, an international journal.

[6]  L. Rabiner,et al.  On the behavior of minimax fir digital Hilbert transformers , 1974 .

[7]  L.J. Thomas,et al.  Automated cardiac dysrhythmia analysis , 1979, Proceedings of the IEEE.

[8]  Olle Pahlm,et al.  A Method for Evaluation of QRS Shape Features Using a Mathematical Model for the ECG , 1981, IEEE Transactions on Biomedical Engineering.

[9]  J. P. C. de Weerd,et al.  Accuracy of QRS detection in relation to the analysis of high-frequency components in the electrocardiogram , 1979, Medical and Biological Engineering and Computing.