In-vitro experimental validation of finite element analysis of blood flow and vessel wall dynamics

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Abstract/Contents

Abstract
Biomechanical forces such as hemodynamic parameters and stress and strain in blood vessel walls have significant effects on the initiation and development of cardiovascular diseases, as well as on the operations of implantable medical devices. Computational fluid dynamics is an emerging powerful numerical tool capable of providing fine temporal and spatial resolutions in the quantifications of these cardiovascular biomechanical forces. The overall goal of this research is to develop tools and methods for conducting in-vitro experiments, and to acquire experimental data for the validation of the computational methods. We first developed a physical Windkessel module which can provide realistic vascular impedances at the outlets of flow phantoms in order to enable in-vitro experiments that mimic in-vivo conditions. We also defined a corresponding analytical model of the Windkessel module, and showed that upon proper characterization, the analytical model can accurately predict the pressure and flow relationships produced by the physical Windkessel module. The precise analytical model can then be prescribed as a boundary condition for the finite element domain, resulting in a direct parallel between the computational description of the physical model and the physical reality. We then performed validation of the numerical method using the Windkessel module, and a rigid, two outlet, patient-derived abdominal aortic aneurysm phantom under resting and light exercise flow and pressure conditions. Physiological pressures within the phantom, and flow waveforms through the two phantom outlets were achieved. Finally, we performed validation of the numerical method incorporating deformable vessel walls, using two compliant flow phantoms under physiological flow, pressure, and deformation conditions. The compliant phantoms mimicked a patent thoracic aorta, and one with an 84% coarctation (by area). The computational predictions of pressure, flow, and velocity patterns compared favorably with experimental measurements in both of the validation studies. The accurate prediction of wave propagation behaviors in the deformable phantom study indicated a faithful prediction of the vessel wall motion. In addition to numerical methods validation, the experimental techniques we have developed can also be used in direct in-vitro evaluations of medical devices.

Description

Type of resource text
Form electronic; electronic resource; remote
Extent 1 online resource.
Copyright date 2011
Publication date 2010, c2011; 2010
Issuance monographic
Language English

Creators/Contributors

Associated with Kung, Ethan Oblivion
Associated with Stanford University, Department of Bioengineering.
Primary advisor Taylor, Charles A. (Charles Anthony)
Thesis advisor Taylor, Charles A. (Charles Anthony)
Thesis advisor McConnell, Michael
Thesis advisor Zarins, Christopher K
Advisor McConnell, Michael
Advisor Zarins, Christopher K

Subjects

Genre Theses

Bibliographic information

Statement of responsibility Ethan Oblivion Kung.
Note Submitted to the Department of Bioengineering.
Thesis Thesis (Ph.D.)--Stanford University, 2011.
Location electronic resource

Access conditions

Copyright
© 2011 by Ethan Oblivion Kung
License
This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).

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