Development of a Korotkov sound processor for automatic identification of auscultatory events. II. Decision logic specifications and operational verification.

An electronic Korotkov sound processor has been developed for the automatic identification of the systolic and diastolic Korotkov sound transitions. This processor incorporates separate circuitry for systolic and diastolic decisions, each with its own defined preprocessing bandpass filter. The decision logic is designed to provide amplitude normalization both within and between subjects, and physiological testing was performed, to optimize the required critical-decision logic parameters. The accuracy of this processor design was evaluated using 32 normal subjects at rest and under orthostatic and ergometric stress conditions. The processor was shown to be quite accurate in its identification of the auscultatory systolic or diastolic event for passive subject conditions; processor accuracy was reduced for subjects participating in ergometric stress.