Estimation of physiological parameters during animal experiment with left ventricular assist system

To develop an effective medical care with the artificial heart, we proposed "Online parameter identification of systemic circulation model using Delta-Operator", which can calculate the time varying and unmeasured hemodynamics of internal human body from some measured physiological data, Aop (Aortic Pressure), AoFlow (Aortic Flow) and Pflow (Pump Flow). This method consists of (a) the second order systemic circulation model, which was configured with Ca (Aortic Compliance), Ra (Aortic Resistance), L (Aortic Inertia) and Rp (Total Peripheral Resistance), and (b) system identification using Delta-operator. In the computer simulation, we could confirm the effectiveness of this proposed method. During the long term animal experiment with artificial heart, which is attached as LVAS (Left Ventricular Assist System), the physiological parameters could be identified as: Ra=0.04 [mmHg sec/ml], Ca=0.7 [mmHg/ml], L=0.02 [mmHg sec sec/ml], Rp=0.3 [mmHg sec/ml]. As a results of this identified parameters, we could estimate the physiological behaviors.. Considering the characteristics of the identified physiological model, the resonant frequency was corresponding to the heart rate. Therefore the optimal control algorithm for the human body will be constructed by the proposed method.