Patent ID: 7591812

Claim:
A passive air purging system to trap and remove air bubbles from venous blood of a patient, undergoing cardiopulmonary bypass using a pump to generate blood pressure, said pump having a pump inlet, the air purging system comprising: a) an air purging blood chamber defined by one or more vertical walls and a first bottom, and a top at a first height, the air purging blood chamber adapted to contain blood and air wherein an interface between the blood and the air occurs at a second height from the first bottom, the chamber having a first horizontal cross section at the second height, said air purging blood chamber having: (i) a first inlet port; (ii) a first outlet port; (iii) an air exhaust port in fluid communication with ambient atmosphere; b) a screen interposed between the first inlet port and the first outlet port, the screen dividing the air purging blood chamber to define a first outlet chamber and a first inlet chamber with the first inlet port entering the first inlet chamber and the first outlet port exiting the first outlet chamber, the screen providing fluid communication between the first inlet port and the first outlet port and inhibiting air bubbles entering the first inlet port from reaching the first outlet port; and c) a structure to handle a venous blood flow of at least 3.5 liters/min; wherein, the air purging system is structured to allow air in the venous blood that enters the first inlet chamber, to rise to the second height in the first inlet chamber where the air is passively purged to the ambient atmosphere and wherein the first horizontal cross section at the second height is less than 60 cm 2 for at least 14 cm from the first bottom.