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Hemodynamics and mechanical behaviors of aortic heart valves: A numerical evaluation

This study investigates the hemodynamics of aortic heart valves under normal conditions as well as two severe diseases, which would be fundamentals for an assessment of mechanical behaviors of polyurethane (PU) prosthetic heart valves. Analysis results highlight that leaflet opening situation and valve geometry affect the shear stress distribution and vortex flow regime. | 2011 4th International Conference on Biomedical Engineering and Informatics (BMEI) Hemodynamics and Mechanical Behaviors of Aortic Heart Valves: A Numerical Evaluation Cheung-Hwa Hsu, Ba-Son Nguyen Ha-Ha Vu Department of Mold and Die Engineering National Kaohsiung University of Applied Sciences Kaohsiung, Taiwan, ROC Department of Mechanical Engineering National Kaohsiung University of Applied Sciences Kaohsiung, Taiwan, ROC Abstract — This study investigates the hemodynamics of aortic heart valves under normal conditions as well as two severe diseases, which would be fundamentals for an assessment of mechanical behaviors of polyurethane (PU) prosthetic heart valves. Analysis results highlight that leaflet opening situation and valve geometry affect the shear stress distribution and vortex flow regime. The interactive impact between low and high wall shear stress on relation to heart valve diseases have been also demonstrated. The results show that low density PU material achieves good hydrodynamic function but produces high stress, while high density PU resists motion of leaflet but reduces the stress significantly. This study also proves that low Young’s modulus PU leaflets achieve good hydrodynamic function while reducing the stress exerted upon the leaflets, and vice versa for high Young’s modulus. Keywords - polyurethane prosthetic valve, aortic valve, hemodynamic, wall shear stress, Young’s modulus. I. INTRODUCTION Nowadays, heart valve disease is one of the biggest health problems all over the world. Heart valve diseases occur in all four heart valves, but most frequently affect the aortic valve being responsible for high mortality rates. There are two main processes that can affect the aortic valve including aortic stenosis and aortic insufficiency. The most common treatment for a malfunctioning aortic valve due to stenosis or insufficiency is replacement of the valve, using mechanical valves, or biological prosthetic valves. Polyurethane valves .