Parameter estimation of left ventricular performance

Intraventricular pressure and volume measurements of the left ventricle are used to estimate the mechanical properties of the myocardium in terms of both passive (due to collagen) and active (due to muscle fibers) properties. The estimation process is based on the least squares method in terms of the intraventricular pressure, which is predicted by a dynamic model of the ventricle as a function of the measured volume. The model is based on the morphologically determined myocardial microstructure in terms of both muscle and collagen fibers. The five free parameters of the model relate to the myocardial passive and active properties and to the activation function. Good agreement between measured and predicted pressures is obtained. The estimated parameters are found to be in the expected physiological range