Abstract
This paper presents two approaches, which we tried, in order to raise the efficiency of assisting the left ventricle, by counterpulsation; 1) Devising a powerful pump; and 2) An ideal timing control of the pumping. Our pump is a pulsator, driven by compressed air, capable of flexible sucking and ejecting manoeuver.
Analyzing the parameters which contribute to the efficiency of assistance, we estimated mathematically, the pumping time adjustment, which would diminish the left ventricular work to the minimal degree. The parameters evaluated include : 1) Position of the catheter tip; 2) Optimal pump stroke volume, as a function of the cardiac stroke volume; 3) Timing of the sucking on; and 4) Sucking phase duration.
From these findings we have calculated and present η as the counterpulsation gain coefficient. Encouraged by experimental data, which well correlate with our estimation, automation by analogue computer has been done to obtain optimal η. By these procedures we have been able to decrease the left ventricular, TTI to about 10%. In other words, we have achieved atrialization of the left ventricle, and thus in this paper, we present more information concerning η.
