Abstract: An air removal device removes air from blood flowing in a perfusion system. A chamber is provided having a blood flow region at a lower end thereof and having an air collection region at an upper end thereof. The chamber further has an inlet, a blood outlet, and an air outlet vertically higher than the inlet. There is a vertical guide structure in the air collection region. A float is disposed for vertical movement following the vertical guide structure, wherein the float has an effective density less than the density of blood. A lever arm having a first end follows vertical movement of the float and has a second end pivotally mounted at a pivot point that is stationary with respect to the vertical guide structure. A valve is coupled to the air outlet and to an intermediate point of the lever arm for closing the air outlet when the float is at its vertically highest position.

Abstract: An input blood supply within a blood perfusion system is pumped through a chamber. A centrifugal flow of the input blood supply is formed in a bottom region of the chamber to cause air to migrate toward an axial center of the chamber. A float is buoyantly suspended on the centrifugal flow wherein the float is disposed for vertical movement in the chamber, and wherein the float has an effective density less than the density of the blood. When a volume of air present within the chamber is less than a predetermined volume, then the float closes a valve at an air outlet from the chamber. When a volume of air present within the chamber is greater than the predetermined volume, then the float opens the valve to remove air from the chamber.

Abstract: Cardioplegia is delivered to a heart vessel by conducting the cardioplegia through an infusion lumen of a cannula. The cardioplegia communicates with a balloon disposed on a distal end of the cannula to cause the cardioplegia to inflate the balloon into sealing contact with a wall of the coronary sinus. The flow of cardioplegia is halted while preventing drainage of cardioplegia from the balloon, to maintain the balloon in its inflated state until such time as the flow of cardioplegia is resumed. Drainage of cardioplegia from the balloon is prevented by causing a valve to be shifted to a closed position blocking communication between the infusion lumen and the balloon. The valve can be shifted manually, or automatically in response to the halting of the delivery of cardioplegia.