On-line computer processing of pressure data from cardiac catheterizations.

A flexible program system for on-line analysis of pressure data from cardiac catheterizations is described. The programs are implemented on an IBM 1800 computer, equipped with remote oscilloscope/keyboard terminals. The current computer system can handle any combination of up to 4 pressure signals. During catheterization, measurement specifications (i.e. calibration levels or sites of pressure recordings) are entered via the keyboard immediately before each recording. As an option the whole expected measurement sequence may be stored on disk before the catheterization starts. This method will minimize the necessary interaction with the computer when the same catheterization procedure is used on several occasions. Changes from the predetermined scheme may, however, be undertaken before each recording to meet with unexpected events that may arise during the catheterization. After computer detection of calibration levels, the recorded signals are digitized during 20 seconds and analysed beat-by-beat. Calculated values are averaged and presented on the terminal oscilloscope in tabular and/or graphic form. The waveform analysis performed by the program system is validated in a statistical comparison between manually and automatically computed values.