Organization of a computer system for measuring the electrical activity of the heart

Abstract

We have approached the study of the electrical activity of the heart by separating the work into two distinct phases - data acquisition and data analysis. The data acquisition program monitors the activity of the heart, samples as many as 24 electrodes simultaneously, and displays them to the investigator. It concurrently executes as many as eleven tasks, uses multiple real time clocks, and allows continuous operator control with exhaustive error checking. The data analysis program tabulates the data previously recorded on tape and allows an operator to select portions to be amplified with respect to time and voltage. Data time sequences can be converted to spatial displays such as contour maps or perspective plots. The program operates by successively applying functions to a data base of over two million bytes. The functions which process the data are organized as an easily expandible set of overlays of about 80,000 program lines. We think that these capabilities can only be achieved by separating the data acquisition from the data analysis.