1981 Volume 10 Issue 2 Pages 469-472
The relation between the stroke volume and the ventricular pressure has been studied in a mock circulation changing the compliance of bellows. Firstly, compliance of four kinds of bellows (buthylrubber molded, siliconrubber sheet, siliconrubber molded and welded bellows of stainless steel) was measured under static conditions. Secondly, the ventricular pressure was measured during the pulsatile flow with various pulse rate in a mock circulation. Thirdly, the actual stroke volume (volumetric change of a ventricle during one stroke) estimated from the compliance of bellows and from the ventricular pressure was compared with the effective stroke volume (flow rate per pulse rate) determined from the measured flow rate and from the measured pulse rate in a mock circulation.
Consequently, it is found that the flow rate of the piston-bellows pump hardly increases with the pulse rate because the stroke volume is governed by the elastic compliance of the bellows. Using a steel bellows of low compliance, the flow rate is able to be controled mechanically. This last type of the pump with steel bellows was connected to the dog which survived for 13h 30.
