Influence Of Blood Flow On The LongitudinalImpedance In Arteries: A Simulation Study

Abstract

Longitudinal impedance is an important parameter in determining local hemodynamic characteristics of blood flow in arteries. It is usually calculated through formulas based on linearized models for blood flow, which are deduced omitting the convective terms in the Navier-Stokes equations. The role of fluid motion nonlinearities in main arteries has been demonstrated both experimentally and computationally in the last two decades. In this paper the attention is focused on the influence of these nonlinearities on the longitudinal impedance when flow rate undergoes to large variations, as may occur in physiological conditions. The study is performed by using a mathematical model previously proposed, which takes into account all the nonlinear terms of the fluid motion and which is solved numerically. The results obtained in the simulated cases show that longitudinal impedance and in particular its resistive component, is highly affected by flow rate.