Estimation accuracy of P wave and QRS complex occurrence times in the ECG: The accuracy for simplified theoretical and computer simulated waveforms

Abstract

One of the main points of interest in the study of the dynamic behaviour of ECG time intervals is the accuracy with which characteristic moments can be estimated in the various waveform segments such as the P wave or QRS complex. In this study, the error involved in such estimation is regarded as due to the superposition of various types of disturbances (noise, hum and fluctuations in amplitude and symmetry) on a supposedly ideal ECG waveform. The effect of these disturbances on estimation accuracy is investigated for three estimation methods (peak estimation, double level estimation and matched filter estimation) by two different approaches; one based on use of a highly simplified theoretical model permitting the derivation of mathematical expressions for the estimation error, and one involving computer-aided simulation of ECG waveforms, based on real ECG data, with various types of disturbances on the basis of recorded ECG data. Both approaches indicate that noise and hum make the main contribution to estimation error, and that matched filter estimation is likely to give best estimation accuracy for both P waves and QRS complexes. © 1984.