Assessment of pulsatile wall shear stress in compliant arteries: Numerical model, validation and experimental data

Abstract

There is evidence that wall shear stress (WSS) is associated with vascular disease. In particular, it is widely accepted that vascular segments with low or oscillatory values of WSS are more probable to develop vascular disease. It is then necessary to establish a realistic model of the blood flow in blood vessels in order to determine precisely WSS. We proposed a numerical 1D model which takes into account the pulsatile nature of blood flow, the elasticity of the vessel, and its geometry. The model allows the calculation of shear stress. It was validated for stationary situations. Then, we computed the time-dependent WSS distribution from experimental data in the sheep thoracic aorta. Results showed that mean WSS calculated through steady flow and rigid walls models is overestimated. Peak WSS values for pulsatile flow must be considered since they resulted to be at least one order higher than mean values. Oscillations in shear stress in a period showed to be approximately of 40%. These findings show that the proposed model is suitable for estimating time-dependent WSS distributions, and confirm the need of using this kind of model when trying to evaluate realistic WSS in blood vessels.

Computational Modelling and Simulation of Fluid Structure Interaction in Aortic Aneurysms: A Systematic Review and Discussion of the Clinical Potential

“…Aricò et al [60] and Silva et al [61] implemented meshless models and reported significant reductions in computational effort. ROM was also suggested as an efficient technique to estimate haemodynamics accurately and reduce reporting time [48,53,117,118]. Liu et al [93] proposed a new optimisation method (Multi-Resolution Direct Search) designed to reduce the high computational effort inherent to inverse methodologies.…”

“…The numerical model presented small errors in pressure and flow measurements, thus proving to be able to accurately capture the main haemodynamic features. Salvucci et al [117] estimated planar WSS using 1D models of the thoracic aorta. The group of Bollache et al [49] developed 1D models based on patient-specific data obtained via CT and MRI scans.…”

Program of Clinical Engineering and Bioengineering-Secretary of Science and Technology-National Technological University

“…Propuestas de control no lineal. Modelo matemático de funcionamiento de corto circuito hidráulico anómalo [5]. Equipamiento para personas con capacidades diferentes Diseño y desarrollo de sistema de bipedestación con funciones automáticas controladas por DSP-PIC.…”