PERFORMANCE EVALUATION OF THE ARMY PULSATILE BLOOD PUMP, MODEL 2,

Engineering tests were performed on a group of Army pulsatile blood pumps Model 2 to determine performance capabilities and variations. The results show that pump output flows and pulse rates increase as outflow resistance decreases. This was determined by testing the size catheters in the outflow tubing. Output flows of more than 4 lmin were achieved when pumping water through a size 16 or larger catheter. Flow and pulse rate were also shown to vary with ventricle stiffness. For a fixed load, pulse rate increases and flow rate slightly decreases as ventricle stiffness is increased. Data were obtained from 23 pumps using a single ventricle and 30 of each of three stiffnesses of ventricles using a single pump. The data from each group fit a normal probability law. The results for the 23 pumps reveal standard deviations of 0.10 to 0.22 lmin for flow rates and 4 to 7 cpm for pulse rates. Similarly, for the ventricles tested, standard deviations range from 0.04 to 0.18 lmin for flows and 5 to 14 cpm for pulse rates, with the higher deviations corresponding to the stiffest ventricle and the lowest with the most pliant ventricle. Author