Method and apparatus for oxygenating and regulating the temperature of blood

A method for regulating the temperature of venous blood in an extracorporeal circuit and simultaneously oxygenating said venous blood comprising the steps of:

• introducing said venous blood and oxygen bubbles into a chamber;
• oxygenating said venous blood by flowing the blood and said oxygen bubbles through paths of restricted area and extended length provided by a flute means formed by an integral hollow rib means along the length of a tube in said chamber;
• and
• regulating the temperature of said blood by flowing heat transfer fluid of predetermined temperature through the interior of said tube and said hollow rib means during said oxygenating step.

A blood oxygenator having an integral heat exchanger for regulating the temperature of the blood flowing in an extracorporeal blood circuit comprising:

• an oxygenating chamber;
• first means for introducing blood and bubbles of oxygen into said oxygenating chamber for forming blood foam within said chamber;
• and
• second means for both (a) oxygenating the blood flowing in said blood circuit by transferring oxygen into the blood and removing carbon dioxide from the blood and (b) simultaneously regulating the temperature of said blood, said second means comprising a heat transfer fluid conduit including heat exchange fluid inlet and outlet means and having rib means along its length, said rib means being located in contact with or closely proximate to the inner wall of said oxygenating chamber so that substantially all of said blood and blood foam produced by said first means flows in contact with external surfaces of said heat transfer fluid conduit through a plurality of restricted area, extended length flow paths around the exterior of the heat transfer fluid conduit provided by said rib means in combination with said inner wall prior to any substantial defoaming of the blood foam and with minimal areas of stagnation for said blood and blood foam with a resulting relatively long residence time po the bloodand blood foam in contact with said heat transfer fluid conduit.

A blood oxygenator having an integral heat exchanger comprising:

• an oxygenating chamber;
• first means for introducing venous blood and bubbles of oxygen into said oxygenator chamber for forming blood foam;
• and
• second means for (a) oxygenating said venous blood by transfering oxygen into the venous blood and removing carbon dioxide from the venous blood and (b) simultaneously regulating the temperature of said venous blood, said second means comprising:
• a heat transfer tube including heat exchange fluid inlet and outlet means and having integral rib means along its length for providing a flute passage means whose total length is considerably longer than the length of said tube, said tube having an overall helical configuration with peripheral portions of said rib means in contact with or closely proximate to a wall of said oxygenating chamber so that substantially all of said venous blood and blood foam flows in contact with external surfaces of said heat transfer tube through a plurality of flow paths of restricted area and extended length around the exterior of said tube prior to any substantial defoaming of the blood foam, said flow paths being with minimal areas of stagnation for said venous blood and blood foam and formed by said flute passage in combination with a wall of said oxygenating chamber for achieving long residence time of the blood and blood foam in contact with said heat transfer tube.

A blood oxygenator having an integral heat exchanger for regulating the temperature of the blood flowing in an extracorporeal blood circuit comprising:

• an oxygenating chamber;
• first means for introducing blood and bubbles of oxygen into said oxygenating chamber;
• and
• second means for both (a) effecting substantially all of the transfer of oxygen into the blood and the removal of carbon dioxide from the blood and (b) simultaneously regulating the temperature of said blood, said second means comprising:
• a heat transfer fluid conduit including heat exchange fluid inlet and outlet means and having a substantially continuous hollow helical rib along its length providing a continuous helical flute passage considerably longer than the length of said fluid conduit, said helical rib being located in contact with or closely proximate to wall means of said blood oxygenator so that substantially all of said blood and blood foam produced by said first means flows in contact with external surfaces of said heat transfer fluid conduit through a plurality of restricted area, extended length flow paths around the exterior of the heat transfer fluid conduit provided by said helical flute passage in combination with said wall means prior to any substantial defoaming of the blood foam with a resulting relatively long residence time of the blood and blood foam in contact with said heat transfer fluid conduit.

A blood oxygenator having an integral heat exchanger for regulating the temperature of the blood flowing in an extracorporeal blood circuit comprising:

• an oxygenating chamber;
• first means for introducing blood and bubbles of oxygen into said oxygenating chamber;
• second means for both (a) effecting substantially all of the transfer of oxygen into the blood and the removal of carbon dioxide from the blood and (b) simultaneously regulating the temperature of said blood, said second means comprising:
• heat transfer means having a plurality of annular ribs along its length providing a blood flow passage considerably longer than the length of said heat transfer means, said ribs being located in contact with or closely proximate to wall means of said blood oxygenator so that substantially all of said blood and blood foam produced by said first means flows in contact with external surfaces of said heat transfer means through a plurality of restricted area, extended length flow paths around the exterior of the heat transfer means provided by said blood flow passage in combination with said wall means prior to any substantial defoaming of the blood foam with a resulting relatively long residence time of the blood and blood foam in contact with said heat transfer means;
• and
• third means coupled to said heat transfer means for supplying or removing heat energy from said heat transfer means.