Wideband External Pulse Recorded During Cuff Blood Pressure Measurement: A New Technique for Cardiovascular Assessment

Figures

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  Fig. 1. a Cuff pressure (Pc) being reduced from above systolic pressure (SP, point A) to below diastolic pressure (DP, point B). Shaded areas above cuff pressure represent positive pressure gradients (arterial pressure–cuff pressure) and shaded areas below cuff pressure represent negative pressure gradients. b Changes in the WEP signal as cuff pressure is reduced from above SP to below SP. With Pc > SP, only the K1 component of WEP is present. With Pc = SP, K2 appears superimposed on the K1 component. With Pc below SP, K3 appears. c Changes in the WEP signal as cuff pressure is reduced from above DP to below DP. With Pc < DP, K2 notch disappears (leaving K3 as the only WEP component) Requires permission from AHA: Hypertension: Blank et. al. Defining DBP in Pregnancy [6]

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  Fig. 2. a Typical K1 Patterns. Top Panel: K1 pattern of young normotensive individual. Bottom Panel: K1 pattern of elderly hypertensive individual. Computation of “K1 Ratio” and “K1R”: K1 Ratio = (Y1 − Y2)/Y3, K1R = ln e (K1 Ratio). b Corresponding K1 patterns and Aortic Pressure Waveforms (according to Murgo et al. [12]. Top row: Aortic pressure waves Bottom row: WEP K1 patterns. Left panel: Murgo Type C aortic pressure wave corresponding to the WEP K1 pattern where the late systolic peak is less than the early systolic peak (K1R > 0). Right panel: Murgo Type A pressure wave corresponding to the WEP K1 pattern where the late systolic peak is greater than the early systolic peak (K1R < 0)

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  Fig. 3. Plot of “K1R vs Age” (with corresponding regression equation). K1R = 1.771 − 0.0353 × age (R2 = 0.33)