Cannula system for a biventricular cardiac support system or a cardiopulmonary bypass system

Claim 1

In combination, a cannula for use in a biventricular cardiac support system or a cardiopulmonary bypass system and a pulsatile flow cardiopulmonary bypass pump, said pump having an inlet and an outlet and a compression chamber intermediate the inlet and outlet of said pump, said compression chamber including a moveable compression plate, a pair of side-by-side externally valved, compressible conduits extending through said compression chamber and under said compression plate, each conduit having an inlet and an outlet, a passive exterior valve positioned at the pump inlet and outlet, said pair of side-by-side conduits extending through said valves, said compressible conduits having portions extending between the inlet and outlet valves forming sacks, the valve at the pump inlet being positioned downstream from the inlets of said conduits, the valve at the pump outlet being positioned upstream from the outlets of said conduits; said cannula comprising first cannula means having a pair of side-by-side first and second lumens adapted to communicate with the left atrium, left ventricle, and aorta of a patient, and second cannula means having a pair of side-by-side first and second lumens adapted to communicate with the right atrium, right ventricle, and pulmonary artery of the patient, a first tube connecting said first lumen of the first cannula means to the inlet of one of said compressible conduits, a second tube connecting the second lumen of said first cannula means to the outlet of said one compressible conduit, a third tube connecting the first lumen in said second cannula means to the inlet of the other of said compressible conduits, a fourth tube connecting the second lumen in said second cannula means to the outlet of other of said compressible conduits, whereby when the inlet valve is open and the outlet valve is closed blood flows from the left atrium, left ventricle, right atrium, and right ventricle through the inlets of the side-by-side conduits into the sack portions of the conduits underneath the pump compression plate, to thereby push the compression plate upwardly until at least one of the sacks is filled, whereupon the compression plate descends to compress the sacks, thereby pumping the blood out of the conduits simultaneously while the inlet valve moves to the closed position and the outlet valve moves to the open position, whereby the pumping rate is automatically varied as a function of the filling pressure, to thereby substantially balance the volume of blood passing from the right atrium and right ventricle to the pulmonary artery with the volume of blood passing from the left atrium and left ventricle to the aorta.