An innovative numerical approach to resolve the pulse wave velocity in a healthy thoracic aorta model

Abstract

Aortic dissection and atherosclerosis are highly fatal diseases. The development of both diseases is closely associated with highly complex haemodynamics. Thus, in predicting the onset of cardiac disease, it is desirable to obtain a detailed understanding of the flowfield characteristics in the human cardiovascular circulatory system. Accordingly, in this study, a numerical model of a normal human thoracic aorta is constructed using the geometry information obtained from a phase-contrast magnetic resonance imaging (PC-MRI) technique. The interaction between the blood flow and the vessel wall dynamics is then investigated using a coupled fluid-structure interaction (FSI) analysis. The simulations focus specifically on the flowfield characteristics and pulse wave velocity (PWV) of the blood flow. Instead of using a conventional PC-MRI method to measure PWV, we present an innovative application of using the FSI approach to numerically resolve PWV for the assessment of wall compliance in a thoracic aorta model. The estimated PWV for a normal thoracic aorta agrees well with the results obtained via PC-MRI measurement. In addition, simulations which consider the FSI effect yield a lower predicted value of the wall shear stress at certain locations in the cardiac cycle than models which assume a rigid vessel wall. Consequently, the model provides a suitable basis for the future development of more sophisticated methods capable of performing the computer-aided analysis of aortic blood flows.

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

“…Azadani et al [91] implemented a code in MatLab that adjusted the parameters of a bidimensional Fung strain energy constitutive model to experimental stress-strain data, obtained from peel and direct tension tests performed on human ascending aorta and aortic sinus samples. Yang et al [92] presented a novel method to estimate aortic wall compliance. This method resorted to uncoupled FSI simulations to estimate PWV.…”

“…Therefore, this metric may be used as a diagnosis methodology. Numerically, excluding a few exceptions [86,92], all the works that aimed to estimate this metric resorted to ROM as it allows the computation of accurate and time-efficient results. Babbs [99] developed 0D models of the systemic circulation to measure cardiac output.…”