Oxygenator

An oxygenator comprising:

• a housing having an interior;
• a blood inlet port in the housing through which blood is adapted to flow, the blood inlet port opening to outside the housing and communicating with the interior of the housing to introduce the blood into the interior of the housing;
• a hollow fiber membrane bundle positioned in the interior of the housing and comprised of a multiplicity of integrated hollow fiber membranes configured to subject the blood introduced into the housing to gas exchange;
• the hollow fiber membranes each possessing a lumen extending between opposite ends of the hollow fiber membrane forming a gas passage for passage of gas;
• a gas inlet port in the housing through which gas is adapted to flow, the gas inlet port opening to outside the housing and communicating with the gas passages of the hollow fiber membranes to introduce the gas into the gas passages;
• a first gas outlet port in the housing through which gas is adapted to flow, the first gas outlet port opening to outside the housing and communicating with the gas passages of the hollow fiber membranes to discharged the gas in the gas passages;
• a blood outlet port in the housing through which blood which has been subjected to the gas exchange is adapted to flow, the blood outlet port opening to outside the housing and communicating with the interior of the housing to discharge from the housing the blood which has been subjected to the gas exchange;
• a bubble filter member positioned at a side of the hollow fiber membrane bundle closer to the blood outlet port and constructed to catch bubbles in the blood which has been subjected to the gas exchange;
• a gas outlet hollow fiber membrane layer positioned between the hollow fiber membrane bundle and the filter member, the gas outlet hollow fiber membrane layer comprising a multiplicity of hollow fiber membranes each possessing a lumen;
• and
• a second gas outlet port in the housing through which bubbles removed by the filter member gas are adapted to flow, the second gas outlet port opening to outside the housing and communicating with the lumens of the hollow fiber membranes forming the gas outlet hollow fiber membrane layer to discharge the bubbles.

A method of performing gas exchange for blood comprising:

• introducing blood into a housing in which are positioned a plurality of hollow fiber membranes each-having a lumen so that the blood flows exteriorly of the hollow fiber membranes;
• introducing gas into the lumens of the hollow fiber membranes to subject the blood flowing exteriorly of the hollow fiber membranes to gas exchange with the has flowing through the lumens of the hollow fiber membranes;
• removing bubbles in the blood while the blood is in the housing and after the blood has been subjected to the gas exchange;
• decelerating the blood from which bubbles have been removed as the blood approaches a blood outlet port in the housing;
• and
• discharging from the housing by way of the blood outlet port the blood which has been decelerated.