Computer Model of Heart

About

Project Description Drs. Peskin and McQueen, and their research team, have invented and implemented software to simulate blood flow in the heart. The project is the result of two decades of research on computational methods to solve the equations of cardiac fluid dynamics. Typically, the design of the prosthetic device under investigation is integrated into the heart model. The computer then generates a prediction of how the device would function in a heart with the anatomical and physiological properties specified by the user. The results can be produced in a variety of forms: movies that illustrate the motion of the blood and tissues, and still pictures that portray information such as flow patterns and pressure contours in the heart. The model recognizes that blood flow is intimately coupled to the motion of the muscular heart walls and the elastic heart valve leaflets. Neither blood flow nor wall motion is specified in advance; instead their coupled equations of motion are solved simultaneously. The approach was first applied to the construction of a two-dimensional model of the left heart. The two dimensional model contains a left ventricle, a left atrium, and a (natural or prosthetic) mitral valve. This work led to a new design of a bileaflet valve, for which a patent has been issued. Also, the two-dimensional model was used to study the influence of the atrioventricular delay during dual chamber pacing on mitral valve closure and on ventricular filling. The study showed that a particular delay maximizes ventricular filling in the model. In the living system this effect would manifest itself as minimization of the left atrial (filling) pressure. The three-dimensional simulator provides a complete computer model of the heart, its valves, and the nearby great vessels. Sources and sinks in the model great vessels connect the model heart to a mock circulation with adjustable properties. The two-dimensional model has been validated by comparison with pressure and flow measurements and with color Doppler flow maps. The three-dimensional model has only recently been completed, but similar validation studies are planned. Applications Major applicatins include parametric studies aimed at optimizing the design of: prosthetic cardiac valves; left ventricular assist devices; total artificial hearts; any device in which a fluid interacts with an elastic structure or vessel of complicated geometry In such studies, device parameters are varied systematically in order to achieve optimal performance according to criteria specified by the user. The simulations make subsequent experimental work more productive by focusing attention on designs which have a high probability of success.