Computer analysis of cardiac catheterization data

The recent introduction of time-sharing computer systems allows several different investigator to use simultaneously the same computer for analysis of real time data. This paper reports on a computer program written for such a system to perform on-line analysis of data from a cardiac catheterization laboratory. Physiologic analog signals from the patient were transmitted to an analog-to-digital conversion unit, which was attached to an IBM 1800 Process Control Computer. After conversion, the data were transferred by the 1800 into an IBM 360/50 digital computer, which was programmed to analyze atrial pressure, ventricular pressure, peripheral pressure (aortic or pulmonary artery), wedge pressure, brachial artery pressure and cardiac output signals obtained during both right and left heart catheterizations. After pertinent data were obtained from the basic signals, the computer was programmed to calculate various derived values, such as systolic and diastolic time intervals, valve gradients, valve areas, stroke work, stroke power and vascular resistances. Important technics were the use of on-off switches to communicate directly with the computer, interaction between the computer and the cardiologist, and safeguards to assure the cardiologist that accurate data were presented for analysis. Preliminary results indicate that such a program and hardware system can be used without specially trained personnel to analyze rapidly and accurately data obtained during cardiac catheterization.