Date of Graduation

5-2020

Document Type

Thesis

Degree Name

Bachelor of Science in Biomedical Engineering

Degree Level

Undergraduate

Department

Biomedical Engineering

Advisor/Mentor

Jensen, Morten

Abstract

Chronic venous insufficiency (CVI) is a form of cardiovascular disease that is caused when valves in the leg become incompetent. Current treatment methods serve to manage symptoms, but there are currently no ways to treat the underlying cause of CVI. A venous valve prosthetic made from a xenograft of a bovine jugular vein is one possible treatment method currently in the research phase. Prosthetic valves must be tested with an accelerated wear tester prior to approval for clinical testing. Although such testers exist for heart valves, physiological differences between heart and venous valves restrict the use those testers on venous valves. An accelerated wear tester, or venous valve fatigue apparatus, was created by a student previously, but failed when the rubber syringe tips melted due to friction. The previous project ran for a total of 10 hours and no conclusive results were determined from subsequent mechanical testing of the valves. The goal of this project was to redesign and rebuild the fatigue apparatus to be more durable, in addition to obtaining quantitative data signifying the machine was working. The fatigue apparatus should create a pressure difference that would drive the valve to repeatedly open and close, wearing the valve out over time. The reconstruction of the apparatus was successfully completed by replacing the syringes used to pump water, with a pneumatic air cylinder connected to a diaphragm. The pneumatic air cylinder causes the diaphragm to expand and contract, moving water with it. Pressure measurements were obtained from the diaphragm, indicating that a maximum pressure 27.24 kPa was created by the diaphragm. Although pressure with a vein would be slightly less, valves close in response to a 1.33 – 5.33 kPa increase. Therefore, the apparatus should function as intended. Testing with a vein was not accomplished in this experiment due to complications from COVID-19 and can be conducted as part of future work.

Keywords

Venous Valve; Prosthetic; Fatigue

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