PURPOSE To create and characterize a physical Windkessel module that can provide realistic and predictable vascular impedances for in-vitro flow experiments used for computational fluid dynamics validation, and other investigations of the cardiovascular system and medical devices. METHODS We developed practical design and manufacturing methods for constructing flow resistance and capacitance ...

The most common descriptor of afterload in the clinical setting is peripheral vascular resistance. Nonetheless, this is only one of the elements of afterload. A comprehensive descriptor of left ventricular extrinsic afterload is contained in the 3-element Windkessel (wind-chamber) model. Although this Windkessel circulatory model contains only characteristic impedance, aortic compliance and per...

In the modeling of the pulse wave in the systemic arterial tree, it is necessary to truncate small arterial crowns representing the networks of small arteries and arterioles. Appropriate boundary conditions at the truncation points are required to represent wave reflection effects of the truncated arterial crowns. In this work, we provide a systematic method to extract parameters of the three-e...

Two competing schools of thought ascribe vascular disease states such as isolated systolic hypertension to fundamentally different arterial system properties. The "windkessel school" describes the arterial system as a compliant chamber that distends and stores blood and relates pulse pressure to total peripheral resistance (R(tot)) and total arterial compliance (C(tot)). Inherent in this descri...

Cerebral blood flow responses to transient blood pressure challenges are frequently attributed to cerebral autoregulation (CA), yet accumulating evidence indicates vascular properties like compliance are also influential. We hypothesized that middle cerebral blood velocity (MCAv) dynamics during or following a transient blood pressure perturbation can be accurately explained by the windkessel m...

Several works have separated the pressure waveform p in systemic arteries into reservoir p(r) and excess p(exc) components, p = p(r) + p(exc), to improve pulse wave analysis, using windkessel models to calculate the reservoir pressure. However, the mechanics underlying this separation and the physical meaning of p(r) and p(exc) have not yet been established. They are studied here using the time...

We extend our recently published windkessel-wave interpretation of vascular function to the wave intensity analysis (WIA) of left ventricular (LV) filling dynamics by separating the pressure changes due to the windkessel from those due to traveling waves. With the use of LV compliance, the change in pressure due solely to LV volume changes (windkessel pressure) can be isolated. Inasmuch as the ...

BACKGROUND With increasing age, some changes appeared in specifications of vessels which including dimensions and elasticity in theirs. The changes in parameters such as resistance, inertance and compliance vessels appear and eventually changes in the environmental pulse releases are in circulation. These changes clearly appear in specification of photoplethysmogram particularly in the size and...

Right ventricular (RV) afterload is commonly defined as pulmonary vascular resistance, but this does not reflect the afterload to pulsatile flow. The purpose of this study was to quantify RV afterload more completely in patients with and without pulmonary hypertension (PH) using a three-element windkessel model. The model consists of peripheral resistance (R), pulmonary arterial compliance (C),...