Structural model of the mitral valve included in a cardiovascular closed-loop model: Static and dynamic validation
A minimal cardiovascular system (CVS) model including mitral valve dynamics has been previously validated in silico. It accounts for valve dynamics using a second order differential equation to simulate the physiological opening valve law. This second order equation is based on output heart signals and is very difficult to match its anatomical or physiological parameters, making this model difficult to interpret and to particularise to pathological situations. In contrast, a simple non-linear rotational spring model of the motion of the mitral valve, located between the left atrium and ventricle, has been validated. A measured pressure difference curve was the model input, which provides an applied torque to the valve chords. Various damping and hysteresis states were investigated to find a model that best matches reported animal data of chord movement during a heartbeat. This model is based on simple physiological behavior modeling, defining parameters that are directly linked with physiological or anatomical data, and is thus more physiologically relevant. This research describes a new closed-loop CVS model integrating the simple non-linear rotational spring model. This new model is shown to fit the static and dynamic heart behaviour observed, as an initial validation of its relevance in a larger CVS model.