Classical electrical and hydraulic windkessel models validate physiological calculations of windkessel (reservoir) pressure

摘要

Our reservoir-wave approach to arterial hemodynamics holds that measured arterial pressure should be considered to be the sum of a volume-related pressure (i.e., reservoir pressure, P reservoir) and a wave-related pressure (P excess). Because some have questioned whether Preservoir (and, by extension, Pexcess) is a real component of measured physiological pressure, it was important to demonstrate that Preservoir is implicit in Westerhof's classical electrical and hydraulic models of the 3-element Windkessel. To test the validity of our Preservoir determinations, we studied a freeware simulation of the electrical model and a benchtop recreation of the hydraulic model, respectively, measuring the voltage and the pressure distal to the proximal resistance. These measurements were then compared with Preservoir, as calculated from physiological data. Thus, the first objective of this study was to demonstrate that respective voltage and pressure changes could be measured that were similar to calculated physiological values of Preservoir. The second objective was to confirm previous predictions with respect to the specific effects of systematically altering proximal resistance, distal resistance, and capacitance. The results of this study validate Preservoir and, thus, the reservoir-wave approach.