Medical Biology & Bioengineering

Hansen A. Mansy received his PhD in engineering from IIT, Chicago, IL in 1990. After postdoctoral training and working in industry, he joined the faculty of Rush University in 2003 and moved to Univedrsity of Central Florida in 2013. His research has focused on investigating vibroacousic phenomena and developing related medical diagnostic tools. He has received significant federal and foundation research funding, published scientific articles, received patents, and continues to serve as an editorial board member and grant reviewer for many national and international organizations (including NIH, NSF, DoD, AFOSR).

There are more than five million patients diagnosed with heart valve disease and about 85,000 heat valve replacements in the US annually. Heart valves act as fluidic control structures to ensure unidirectional blood flow and prevent backflow. When valves malfunction, a replacement is often necessary in severe cases. For example, without valve replacement the survival rate in severe aortic stenosis patients is about 50% two years after the onset of symptoms. Artificial heart valves, both bioprosthetic and Commercial valves, have been utilized for many years to replace dysfunctional heart valves. The first part of the current study presents an investigation on a Commercial bileaflet mechanical heart valve with various percentages of valve opening angle. Comparison of velocity, pressure, shear stresses and vorticity profiles for different leaflet angles that represent valve dysfunctions is discussed in the current research. Valve leaflets are propelled to open and close during the cardiac cycle due to the forces applied by pulsatile blood flow on heart leaflets. Hence in the second part, a computational method is exploited to simulate the flow dynamics through the heart valve during leaflet motion influenced by pulsatile blood flow from the full open and closure positions. The results show variations in velocity and pressure gradients through the heart valve which can be an indication of heart valve dysfunction and the cardiac flow through normal valve and in the vicinity of the mechanical leaflets during valve motion.