Low-frequency Korotkoff signal analysis and application

The low frequency (LF) components of the Korotkoff signal are recorded, analyzed, and applied in the derivation of blood pressure estimates. The LF components are found to be the dominant feature of the Korotkoff signal throughout the entire occlusive cuff deflation cycle, and a sharp rise in the energy of these components is found to correlate with the occurrence of systolic pressure. This feature is applied in 2 separate energy thresholding algorithms which produce estimates of systolic blood pressure which correlate well (r=0.907 and r=0.938) with those systolic pressure derived via the auscultatory technique.