Velocity detection of Korotkoff sounds.

High-speed oscillograms were made showing the time relationships between the ECG and arterial pressure waves detected by three microphones successively placed beneath a standard blood pressure cuff along the brachial artery. As the cuff was deflated through the systolic/diastolic range, the indicated propagation velocity of the Korotkoff waves changed from approximately 1 m/sec near systolic pressure to about 2.5 m/sec near diastolic pressure.