A three-dimensional coupled fluid-structure computational model of mitral valve function

The purpose of this study was to develop a three-dimensional coupled fluid-structure dynamic model of the mitral valve, in order to determine the stress-strain distribution in the valve, as well as the blood flow patterns. The valve leaflets were represented by orthotropic nonlinear elements and the chordae were represented by linear elements (LS-DYNA). The structural solution was computed using a Lagrangian method. Blood was represented by eight noded brick elements with elastic fluid material. The fluid solution was computed using an Eulerian method. Physiologic pressure wave profiles were input for both diastole and systole. The results demonstrated physiologic opening and closing of the valve, and time to leaflet closure was 30 msec after the onset of systole. Stress was highest in the anterior leaflet 825 kPa, the maximum flow velocity was 500 mm/sec, and peak systolic pressure was 120 mmHg. This coupled fluid-structure model represents an advance in modeling of the mitral valve, and will be used to further assess pathologic conditions as well as surgical intervention