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Deenna Doan, Clare Hillshafer, and Dr. Chung-Hao Lee, School of Aerospace and Mechanical Engineering, University of Oklahoma, 660 Parrington Oval, Norman, OK 73019
The aortic valve (AV) regulates blood flow between the left ventricle and the aorta, while the pulmonary valve (PV) separates the right ventricle and the pulmonary artery. Contrary to the atrioventricular heart valves that use induced pressure differences from the electric cardiac cycle to open the valve from expansion and contraction of the ventricles, the AV and PV, with a semilunar (or half-moon) shape, rely on pressure differences at the cusp region, to act against gravity due to their location in the heart. Additionally, prior studies in the literature have expressed their concerns for the need for more understanding in the field of tissue engineered heart valves. Due to the lack of information regarding the microstructural and mechanical behaviors and properties of these semilunar heart valves, much remains to be learned to help work towards developing an alternative in the heart valve replacement field. The proposed project included the procurement of porcine hearts (n=12) and careful dissection of the PV and AV leaflets into 6.5x6.5mm sized specimens. The extracted leaflets experienced biaxial testing to characterize the deformation and force as the leaflet undergoes various biaxial displacements, as well as polarized spatial frequency domain imaging (pSFDI) testing to examine how the collagen fiber architecture (CFA) orientates at different loading ratios. An expected observation is seeing a shift in the CFA post-mechanical testing that will result in a greater alignment in the direction of the applied loading. For the AV and PV, there is a significant need to further understand the CFA realigns in regard to the pressure differences that is experienced in in vivo configuration. Additionally, with a more complete understanding of the collagen fiber reorientation will allow for the improvement of clinical therapeutics.
Presenters: Deenna Doan, Clare Hillshafer
Institution: University of Oklahoma Norman Campus
Type: Poster
Subject: Engineering
Status: Approved
