Okanagan valve : the next generation of mechanical heart valves
department or school: Applied Science, Faculty of
department or school: Engineering, School of (Okanagan)
data provider: DSpace
degree campus: UBCO
creator: Bhullar, Arpin Singh
issued: 2020-04-15T21:29:41Z
issued: 2020
related degree: Master of Applied Science - MASc
degree grantor: University of British Columbia
description: Valvular heart disease is a cardiovascular condition characterized by damage to any number of the four valves within the human heart. This damage can be defined as stenosis or incompetence based on a valveâs inability to completely open or close, respectively. Stenosis and incompetence are caused by calcification and the thickening of valvular tissue, and often manifest as angina, ultimately leading to congestive heart failure if left untreated. Mechanical heart valves (MHV) can be surgically implanted to replace a failing valve but require the prescription of life-long anticoagulant medication such as Warfarin to mitigate blood clotting issues. The thrombogenicity of MHVs is related to their poor hemodynamics, believed to be caused by the high shear stresses they induce. Some identified regions of high shear stress are the hinges, the trailing edges of the leaflet tips, and velocity jets. These problems have plagued the most common form of MHVs, bileaflet mechanical heart valves (BMHVs), for decades as their designs have stagnated. This research was conducted to design and validate a BMHV that would have similar hemodynamic properties to native heart valves, enabling implantation without reliance on post-operative anti-coagulants. To accomplish this, we identified the major design limitations of BMHVs, such as the gold standard St. Jude Medical Regent BMHV, as well as the believed contributing factors to their thrombogenicity. We developed a novel design architecture for BMHVs that addressed these limitations, and from it, the Okanagan Valve (OKV). A numerical analysis was performed on modifications of interest incorporated in the OKV to determine their effect on heart valve hemodynamics. In-vitro methods were utilized to experimentally observe the performance of the OKV. Our experimental assessment of the OKV found the maximum regional backflow velocity and closing volume to be 46 m/s and ~5 cc, respectively, values closer to those of a bioprosthetic valve rather …
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/74029
note: Okanagan Valve: The Next Generation of Mechanical Heart Valves by Arpin Singh Bhullar B.ASc., The University of British Columbia, 2017 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF APPLIED SCIENCE in THE COLLEGE OF GRADUATE STUDIES (Mechanical Engineering) THE UNIVERSITY OF BRITISH COLUMBIA (Okanagan) April 2020 © Arpin Singh Bhullar, 2020 ii The following individuals certify that they have read, and recommend to the College of Graduate Studies for acceptance, a thesis/dissertation entitled: Okanagan Valve: The Next Generation of Mechanical Heart Valves submitted by Arpin Singh Bhullar in partial fulfillment of the requirements of the degree of Master of Applied Science in Mechanical Engineering Examining Committee: Dr. Hadi Mohammadi, Mechanical Engineering Supervisor Dr. Ray Taheri, Mechanical Engineering Supervisory Committee Member Dr. Bahman Naser, Civil Engineering Supervisory Committee Member Dr. Liwei Wang, Electrical Engineering University Examiner iii Abstract Valvular heart disease is a cardiovascular condition characterized by damage to any number of the four valves within the human heart. This damage can be defined as stenosis or incompetence based on a valveâs inability to completely open or close, respectively. Stenosis and incompetence are caused by calcification and the thickening of valvular tissue, and often manifest as angina, ultimately leading to congestive heart failure if left untreated. Mechanical heart valves (MHV) can be surgically implanted to replace a failing valve but require the prescription of life-long anticoagulant medication such as Warfarin to mitigate blood clotting issues. The thrombogenicity of MHVs is related to their poor hemodynamics, believed to be caused by the high shear stresses they induce. Some identified regions of high shear stress are the hinges, the trailing edges of the leaflet tips, and velocity jets. These problems have plagued the most common form of MHVs, bileaflet…
has type: Thesis/Dissertation
date issued: 2020-05
is shown at: 10.14288/1.0389828
language: eng
degree discipline: Mechanical Engineering
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
type: Text
identifier URI: http://hdl.handle.net/2429/74029