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Development of an in vitro system for cardiovascular flow measurements and computational study of cerebral aneurysm hemodynamics

University of British Columbia

As the population ages, the prevalence of the cardiovascular disease, which is the leading cause of death in the world, is projected to increase. The aneurysm is a cardiovascular disease which can be defined as an excessive localized enlargement of an artery caused by a weakening of the artery wall. Abdominal aortic aneurysm (AAA) and intracranial aneurysm (IA) are the most propense aneurysm types to develop. When the aneurysm enlarges, there is a high risk of aneurysm rupture which can lead to serious bleeding, or even death. The causes of aneurysm initiation, progression, and rupture are complex and not fully comprehended. However, it is well accepted that hemodynamics has an essential role in the aneurysm development and progress. The main objective of this thesis is to implement a joint experimental-computational approach to study the aneurysms. The first specific objective was to design and build an in vitro experimental setup which can mimic the hemodynamics for different circulatory regions with tunable physiological conditions. The benchtop system was specifically developed to increase experimental efficiency and maintain high experimental accuracy. The experimental setup was used to replicate the physiological flow and pressure conditions as found in an AAA. The second specific objective was to study intracranial sidewall aneurysms. A computational fluid dynamics (CFD) analysis was conducted to study sidewall aneurysm hemodynamics. An idealized aneurysm geometry was used to determine the effect that a stent treatment device had on aneurysm hemodynamics. Newtonian and non-Newtonian working fluids, matching the human blood density and viscosity, were considered. The study showed that using a Newtonian model, the hemodynamic parameters were overestimated in the intra-aneurysmal sac region in comparison to the non-Newtonian model. Furthermore, the presence of the stent device showed an alteration on the flow patterns inside the aneurysm sac by reducing the overall aneurysmal blood flow velocity.

Text

2019-12-04

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/72553

Biomedical Engineering

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/