analyzing the effect of stent geometry for polymeric aortic HEART valves Atieh Y. Koupaei, Brandon L. Moore , David L. Bark Jr. , David A. Prawel, Lakshmi P. Dasi Department of Mechanical Engineering, Colorado State University School of Biomedical Engineering, Colorado State University Introduction Aortic valve disease is one of the major causes of death. Several drawbacks are associated with existing bioprosthetic and mechanical HVs such as durability and thrombosis, respectively. Polymeric aortic prosthetic HVs can overcome durability issues, may be designed to reduce antithrombotic therapy, and may reduce current production costs. Results Particle Image Velocimetry Parameters to recover regurgitation fraction: Long Profile No Arch 1) H/D Effect 2) h/D Effect Acceleration Peak Deceleration Distole Acceleration Peak Deceleration Distole The aim of this work is to initiate the design of low-cost tri-leaflet polymeric AHVs, by determining geometries that result in hemodynamic performance comparable to bioprosthetic HVs. Short Profile Short Arch Short Profile Short Arch Medium Profile Long Arch Short Profile Medium Profile 𝝎 𝒛 ( 𝒔 −𝟏 ) velocity field along the center plane of one leaflet shows that adding arches to the leaflets results in a more stable and developed fluid flow in the upstream. Methods & Materials Design and Manufacturing Short Arch Medium Profile High Profile TopPart Bottom Part Arch Length = h Long Profile No Arch 3) Flexible Stent Effect ABS Height = H A HV design with low profile is desired to reduce obstruction of other structures in the heart. Adding arches or flexibility will help achieve better commissural contact while having lower profile. 𝝅𝑫 Short Profile Rigid Stent LLDPE uPrint SE Short Arch Medium Profile Height to Diameter Aspect Ratio   Low profile Medium profile High profile H/D 0.6 0.7 0.88 Short Profile Flexible Stent 𝑹𝑺𝑺 ( 𝒅𝒚𝒏𝒆𝒔 𝒄𝒎 𝟐 ) Reynolds shear stresses are higher in the shorter profile valve, but they show similarity to the reported values for RSS. The maximum values were primarily concentrated around the centerline. Valves without arch Regurgitation percentage analysis Parameters used to design leaflets   No arch Short arch Long arch h/D 0.081 0.116 Summary Higher stent profiles resulted in better coaptation. Arches reduce the gap between leaflets and increase coaptation. A flexible stent adds a degree of freedom to the stent posts and results in much better coaptation. Further hemodynamic analysis needs to be performed to characterize valve performance. Flexible stent High profile no arch Short profile no arch Short Profile short arch Short profile long arch Medium profile no arch Medium profile short arch Flexible stent short profile Valves with arch Aortic Flow Rate (Lit/min) Experiments Flow Loop Setup for Imaging & PIV Acknowledgements Research reported in this abstract was supported by the National Institutes of Health under award number R01HL119824. Time (s) Increment in HV height shows decrement in regurgitation. the short profile is preferred and can result in approximately similar regurgitation with added arches References 1. Yacoub MH & Takkenberg JJM, Nat Clin Pract Card, 2:60-61, 2005. 2. Black MM & Drury PJ The Pathology of Devices, 127-159, 1994. 3. Yap CH et al., Biomech Model Mechan, 11:171–82, 2012. 4. Moore BL & Dasi LP ASME 2013 Summer Bioengineering Conference, V01AT04A009-V01AT04A009, 2013. 5. Leo, Hwa Liang, et al. Fluid dynamic assessment of three polymeric heart valves using particle image velocimetry, Annals of biomedical engineering 34.6, 936-952, 2006 Aortic Pressure Ventricular Pressure LabVIEW Controlled Regurgitation Percentage = 𝑅𝑒𝑣𝑒𝑟𝑠𝑒 𝐹𝑙𝑜𝑤 𝑇𝑜𝑡𝑎𝑙 𝐹𝑙𝑜𝑤 Heart Rate 60BPM Ave. Cardiac Output 5 L/min Normal BP 120/80 mmHg SB3C 2015 Summer Biomechanics, Bioengineering, and Biotransport Conference Snowbird, Utah, June 17-20, 2015