Wave Propagation in Thin-Walled Aortic Analogues

Abstract

Research on wave propagation in liquid filled vessels is often motivated by the need to understand arterial blood flows. Theoretical and experimental investigation of the propagation of waves in flexible tubes has been studied by many researchers. The analytical one-dimensional frequency domain wave theory has a great advantage of providing accurate results without the additional computational cost related to the modern time domain simulation models. For assessing the validity of analytical and numerical models, well defined in vitro experiments are of great importance. The objective of this paper is to present a frequency domain analytical model based on the one-dimensional wave propagation theory and validate it against experimental data obtained for aortic analogs. The elastic and viscoelastic properties of the wall are included in the analytical model. The pressure, volumetric flow rate, and wall distention obtained from the analytical model are compared with experimental data in two straight tubes with aortic relevance. The analytical results and the experimental measurements were found to be in good agreement when the viscoelastic properties of the wall are taken into account.

Development of a Blood Flow Model and Validation Against Experiments and Analytical Models

“…Wormersly was one of the pioneers and mostly referenced in analytically modeling of wave propagation. His work is now known as the Womersley theory and will be recapitulated below using [6,19].…”

“…The work of Womersley is describing the theory for a vessel that is infinitely long and needs modification to be able to use it for a finite length vessel with closed ends. In [6] is described how reflecting waves can be determined. Here a tube of length L is considered starting at z = L 0 and ending at z = L 1 , see Fig.…”

“…Experiments have been performed in order to understand wave propagation and to validate analytical and experimental models. The experiments can be categorized as in-vivo [1][2][3] and in-vitro [4][5][6][7][8][9] experiments.…”

“…In Comsol the Iterative over each time step method is used. The geometrical dimensions and physical properties for both the fluid and solid are the same as the ones used in [6]. This will allow the comparison of the finite element model developed in this paper with the analytical and experimental data presented in [6].…”