Computer simulation of blood flow in the human arm

Abstract

This paper considers a finite element method to characterize blood flow in the human arm arteries. A set of different pressure waveforms, which represent normal and diseased heart pulses, is used for the proximal boundary conditions, and a modified Windkessel model is used for the distal arterial boundary conditions. A comparison of the distal pressure and flow waveforms, for each different proximal pressure, is made to determine whether such waveforms are significantly altered from normal waveforms. The results show that the distal pressure and/or flow waveforms in certain cases are sufficiently different to be possibly used as a diagnostic indicator of an abnormal heart condition. Also considered is the effect of stenosis, change of compliance, and dilatation of the distal beds on the pressure and flow waveforms. A stenosis which has an area reduction of greater than approximately 75% is found to significantly alter both the distal pressure and flow waveforms. Changes in arterial compliance, however, do not strongly influence the waveforms. Dilatation of distal vascular beds is simulated by reducing the lumped resistance of these beds, and this reduction increases mean flow and decreases mean distal pressure, but has little effect on the basic shape of either the pressure or flow waveform.

Accuracy of the wave equation in predicting arterial pulse propagation

“…For a Poiseuille flow profile, α = 1.33 and k R = 8π ν while for the clinically measured flow profile, a value of α = 1.1 and k R = 21π ν has been suggested [11,[24][25][26]. α = 1 assumes a completely flat profile, but it is often used as it permits significant mathematical simplification [27] (see Fig.…”

Simulation of pulsatile flow in arteries using the finite-element method

“…A simple representation of the arteries in the human arm would be an arterial segment-the brachial artery-leading to a bifurcation. The branch produces two similar arteries-the radial and ulnar arteries (Balar 1985). These can be modeled in two ways.…”

“…First, both radial and ulnar artreies can be treated as having equal lengths and terminating at identical lumped impedances; and second, the ulnar artery can be The parameter values for the lumped Impedances and the main artery are taken from Balar (1985) and presented in Table 5.9. The Input pressure waveform is also taken from Balar (1985) with the Fourier coefficients used to simulate this waveform given in Table 5.10. Balar (1985).…”

Inlet boundary conditions for blood flow simulations in truncated arterial networks

“…With this reflecting BC, waves arriving at the inlet interface are reflected back into the computational domain. This type of BC permits to model aortic valve closure (Matthys et al, 2007;Urquiza et al, 2006) but is also used by default in many truncated arterial domains (Raines et al, 1974;Balar et al, 1989;Alastruey et al, 2007;Bertolotti and Deplano, 2000;Leguy et al, 2010).…”

“…It can include the complete arterial tree (Stergiopulos et al, 1992) or a network limited to some arteries (Balar et al, 1989;Raines et al, 1974;Zhao et al, 2000). In the model of the complete arterial tree, the inlet BC intends to reproduce the impulsion from the heart.…”