Analysis of Flow and Wall Deformation in a Stenotic Flexible Channel Containing a Soft Core, Simulating Atherosclerotic Arteries

Abstract

A novel eccentric stenotic channel was manufactured to provide an in vivo physical environment simulating an atherosclerotic artery. It was composed of an elastic wall containing a soft semi-cylindrical volume that simulated a lipid core. Wall strain and fluid shear stress distributions were computed using a finite element method incorporating fluid structure interaction. The particle image velocity measurement method was extended to measure wall deformation and wall deformation and flow velocity were simultaneously measured to validate the computational method. The maximum deformation was found to occur in the distal shoulder, while the maximum flow wall shear stress was skewed to the proximal shoulder of the lipid core. Measured maximum wall deformations and flow velocities agreed with the computational results within a 10% margin of error. The wall shear stress on the stenotic wall varied from 0 to 1.2 Pa. The maximum shear strain in the longitudinal plane and the normal strain in the transverse plane for the Core 1 model (Young’s modulus 50 kPa) were 3.8% and 0.7%, respectively. The maximum shear and normal wall strains for the Core 2 model (Young’s modulus 200 kPa) were 34% and 14% lower. These wall stress and strain values corresponded with those found in human atherosclerotic arteries. The developed channel could provide spatial and temporal variations as well as magnitudes of wall shear stress and strain observed in atherosclerotic arteries.