Automatic Analysis of the P-QRS-T Complex of the Electrocardiogram by Digital Computer

Abstract

Automatic procedures for the analysis of the P-QRS-T complex of the ecg were developed. Orthogonal 3-lead records are being recorded on magnetic analog tape using FM channels. Consequently, the tracings are converted into digital form in order to become acceptable to a digital computer. First a computer program had to be developed for the automatic recognition of beginning and end of ecg waves. This procedure leads to determinations of wave durations and intervals in between them. Other computer programs were developed for determinations of the spatial gradient and its components SA QRS and SAT, polar vectors and Eigenvectors, instantaneous vectors during QRS and ST, curves of spatial magnitude, velocity, and orientation, and measurements of various wave amplitudes and durations. The computer programs were successfully tested in more than 3,000 records. Statistical computer programs were also developed for obtaining a differential diagnosis in each individual case, based on probability density distribution of the findings. Automatic analysis of the ecg was found to exceed largely conventional types of analysis in diagnostic recognition rates.