DEVELOPMENT OF A CONTROL ALGORITHM FOR A ROTARY BLOOD PUMP - PREDICTION OF RECOVERY FROM CARDIAC-FAILURE

Under extracorporeal membrane oxygenator (ECMO) support, it is difficu lt to predict recovery of cardiac function. The authors examined the r otary blood pump function curve and developed a new index of dynamic v ascular impedance (DVI) for controlling the ECMO system. The cases of nine patients assisted by ECMO after cardiac surgery were analyzed. Th e index of DVI was calculated from the pump flow and the pressure diff erence (delta pressure) between the inlet and outlet of the pump. Seve n patients were weaned from support. In the patients with recovery of cardiac function, the index of DVI was high and the delta pressure con verged on the specific value. Analysis of the rotary blood pump functi on curve during ECMO support reflects the pump characteristics and pro vides data for the management of pump speed. The index of DVI can be u sed to predict the timing for weaning patients from ECMO support. The authors are developing an automatic control system that uses the index of DVI.