A COMPUTER-CONTROLLED MOCK CIRCULATORY-SYSTEM FOR MONOVENTRICULAR ANDBIVENTRICULAR ASSIST DEVICE TESTING

The clinical use of heart assist devices for heart recovery, implies t he problem of their in vitro testing and training to use. in a mock ci rculatory system developed to this aim, the main problem is reproducin g interaction among the device, the ventricle and the circulatory netw ork. This can be analysed by the position, on the p-v plane, of the wo rking point defined by the intersection between end systolic ventricul ar (ESPVR) and arterial elastance lines. The system developed on this basis, connectable to mono-and biventricular parallel assist devices, was a closed loop model including systemic and pulmonary circulation. The arterial trees were reproduced by two windkessels with adjustable peripheral resistance, and the Starling's law of the heart by a variab le elastance model. The software controls and monitors circulatory par ameters and variables. Results showed the behavior of the system with preload or afterload changes. Further, the reproduction of physiologic al, pathological (obtained by modifying slope and volume intercept of the ESPVR line) and LVAD assisted circulatory conditions was shown. Th e assistance effect was underlined by the changes in the ventricular w ork cycle and in hemodynamics variables. The evaluation of the effect of device control strategy on the ventricle and its energetics (on p-v plane) were among the main characteristics of this system which ought to be further improved to test devices such as the IABP, which requir es a different aortic model.