Identification of Time-Varying Ventricular Parameters During the Ejection Phase

Physical parameters representing the energy components of the cardiac pump related to inertance, resistance, and compliance are developed. A method utilizing estimation techniques is presented to determine these time-varying parameters as well as the end diastolic volume. The method is applied to the ejection phase, using pressure and flow measured at the root of the aorta and at the pulmonary artery for left and right ventricles, respectively. Uniqueness of the estimates and sensitivity of the parameters to noise in the measured variables are evaluated. The effect on the estimated parameters due to altered problem constraints is also examined.