Wave propagation in a model artery

TL;DR

This study experimentally investigates wave propagation in a model artery, revealing how pre-stress influences wave dispersion and highlighting implications for understanding arterial pulse waves and material property estimation.

Contribution

It introduces an experimental setup with synthetic Schlieren imaging to analyze wave behavior in a deformable artery model, incorporating acoustoelastic theory to explain pre-stress effects.

Findings

Pre-stress significantly alters wave dispersion in the artery model.

A single dispersive wave mode resembling heartbeat pulse waves was observed.

The model links static deformation and stretching to wave propagation characteristics.

Abstract

Fluid filled pipes are ubiquitous in both man-made constructions and living organisms. In the latter, biological pipes, such as arteries, have unique properties as their walls are made of soft, incompressible, highly deformable materials. In this article, we experimentally investigate wave propagation in a model artery: an elastomer strip coupled to a rigid water channel. We measure out-of-plane waves using synthetic Schlieren imaging, and evidence a single dispersive mode which resembles the pulse wave excited by the heartbeat. By imposing an hydrostatic pressure difference, we reveal the strong influence of pre-stress on the dispersion of this wave. Using a model based on the acoustoelastic theory accounting for the material rheology and for the large static deformation of the strip, we demonstrate that the imposed pressure affects wave propagation through an interplay between stretching, orthogonal to the propagation direction, and curvature-induced rigidity. We finally highlight the relevance of our results in the biological setting, by discussing the determination of the arterial wall's material properties from pulse wave velocity measurements in the presence of pre-stress.