Abstract
In the case of severe cardiogenic shock, the combined use of Intra-aortic Balloon Pumping (IABP) and Veno-arterial Bypass (VAB) is more effective than the separate use of the each. We made a device possessing the combined function of the above two in a single unit. It is composed of two parts, a oneway valve and a pulsatile chamber containing 30 ml balloon driven by AVCO-7 IABP system. (Fig. 1)
The venous cannula is connected to the valve and the chamber next. And this chamber pumps out blood to the ascending aorta directly through the arterial cannula. (Fig. 2) Balloon inflation of this device is designed to let out the blood in single direction, the arterial side. While the balloon deflation is designed to suck blood from both ends, the arterial and the venous sides.
Using the experimental model (Fig. 3), hemodynamic effects were observed by changing arterial pressure, heart rate and arterial cannula size.
As the arterial pressure decreases, the ratio of the venous inflow sucked into the chamber increases, (Fig. 4)
This means the device functions mainly as a counterpulsator while the arterial pressure maintains. And it functions as a pulsatile VAB device in accordance with the decline of the arterial pressure.
