LUMPED PARAMETER MODEL OF THE MITRAL VALVE IN CIRCULATION SYSTEM
Guijie Zhang1, Zhaoming He1,2,
1Research Center of Fluid Machinery Engineering and Technology, China;
2Texas Tech University, USA
Multiscale modeling of circulation system usually requires coupled a lumped parameter model of circulation system plus a local 3D CFD model. Mitral valve is usually considered a diode to control unidirection flow in the circulation model not reasonable for study of downstream cardiovascular hemodynamics because of passive limited backward flow during closing process which is a complicated fluid-structure interaction. This paper aimed to develop a new lumped parameter model of the heart valve based on the mitral valve hemodynamics. The new mitral valve model was a model of varied flow resistance allowing for a closing time, closing volume, blood inertia, and steady flow of opened and closed phases. The model included the varied resistance and blood inertia in a serial connection. The resistance was assumed to be an exponential function during the closing process, and otherwise a leaflet kinetic model allowing for the flow shear and pressure forces. The closing volume and closing time were obtained from experiment to reflect empirical dynamics of the mitral valve during valve closing. This model was used in the left heart circulatory system to simulate hemodynamics in the system with a Matlab code based on the system. The results were compared with the published results of mitral valve and indicated that the developed model revealed the characteristics of opening and closing of mitral valve. In conclusion, the new lumped parameter model of the mitral valve is developed successfully and accurately represents the valve hemodynamics in a relatively low computational cost. This model offers more reasonable boundary conditions for a local downstream 3D CFD study in the multiscale modeling of the cardiovascular system.