Patent ID: 8142546

Claim:
A method of oxygenating blood comprising: introducing blood into a blood inflow port communicating with an interior of a housing containing a hollow fiber membrane bundle, the hollow fiber membrane bundle being comprised of a plurality of gas exchanging fiber membranes each having a lumen; conveying an oxygen-containing gas through the lumens of the gas exchanging fiber membranes while the blood flows into gaps in the hollow fiber membrane bundle to subject the blood to oxygenation and produce oxygenated blood; separating air bubbles in the oxygenated blood from the oxygenated blood by virtue of the oxygenated blood passing through a filter member positioned in contact with the hollow fiber membrane bundle, a pressure differential between a blood side of the gas exchanging fiber membranes and the hollow interior of the gas exchanging fiber membrane lumens causing air bubbles which are trapped by the filter member to enter into the gas exchanging fiber membranes; conveying the air bubbles separated from the oxygenated blood through the lumens of the gas exchanging fiber membranes; flowing the blood which has passed through the filter member to a blood chamber in the housing; and conveying the blood in the blood chamber out of the housing by way of a blood outflow port.