Individualization of the parameters of the 3-element Windkessel model using carotid pulse signal

Hemodynamic of the arterial system can by describe by tree-element Windkessel model. Because it is a lumped model it doesn’t account a pulse wave propagation. Pulse wave velocity, reflection of waves and pulse pressure profiles change are not present in the model. Modelflow© methods use a three-elements Windkessel model to calculate the stroke volume and total peripheral resistance from arterial blood pressure pulse.
Three-elements model consisting of a aortic input impedance (Z0), a total peripheral resistance (TPR) and a arterial compliance (CW). The model parameters are obtained on the basis of in vitro studies on human aorta preparation. It is taken into account a age and gender of patients. It should be noted that not only age determines a arterial compliance, same disease affect on it. Relying only on age may lead to inaccuracies.
Modelflow© methods use non-invasive pulse pressure recording from the finger (Finapres). Pulse wave in the radial artery are remarkably different from those in a aorta so Modelflow© can be inaccurate. It is reasonable to use pulse pressure obtained from the point as close to heart as it is possible.
Reliability of Modelflow© method applied to pulse pressure profile obtained from finger is questioned. In the present study, based on analyze of Windkessel model, we demonstrated that carotid pulse partly can by use to specify individual value of a arterial compliance and a aortic input impedance. Farther carotid pulse can by use to determine individual transfer function of the circulatory system, which can be used to calculate aortic pressure in better way.
Despite its limitations Windkessel model substantially describe phenomena that take place in arterial system. It describes the function and state of circulatory system. Individualization of the model parameters will increase reliability of results obtained from the model.

Author: Marek Żyliński
Conference: Title