Report Number: CS-TR-65-21
Institution: Stanford University, Department of Computer Science
Title: Vectorcardiographic analysis by digital computer, selected results
Author: Fisher, Donald D.
Author: Groeben, Jobst von der
Author: Toole, J. Gerald
Date: May 1965
Abstract: Instrumentation, recording devices and digital computers now may be combined to obtain detailed statistical measures of physiological phenomena. Computers make it possible to study several models of a system in depth as well as breadth. This report is concerned with methods employed in a detailed statistical study of some 600 vectorcardiograms from different "normal" individuals which were recorded on analog magnetic tape using two different orthogonal lead systems (Helm, Frank) giving a total of 1200 cardiograms. A "normal" individual is defined as one in which no abnormal heart condition was detected by either medical history or physical examination. One heartbeat in a train of 15 or 20 was selected for digitization. An average of 1.2 seconds worth of data was digitized from each of the three vector leads simultaneously at a rate of 1000 samples per second for each lead giving a total of over ${4.10}^6$ values. Statistical models by sex and lead system of the P wave and QRS complex (at 1 millisecond intervals) and T wave (normalized to 60 points in time) were obtained for 43 age groups from age 19 to 61 in rectangular coordinates, polar coordinates and ellipsoidal fit (F-test) coordinates. Several programs were written to perform the analyses on an IBM 7090. Two of the programs used 300000+ words of disk storage to collect the necessary statistics. Various aspects of the study are presented in this report.