Blood oxygenator

A blood oxygenator for admixing blood and oxygen for absorption of oxygen and release of carbon dioxide comprising:

• an oxygenating chamber;
• first means for introducing blood and oxygen into said oxygenating chamber comprising venous blood and oxygen inlet means therein;
• second means coupled to said oxygen inlet means for introducing a plurality of bubbles of oxygen in the venous blood;
• third means for producing substantial mixing and churning together of the blood and oxygen bubbles sufficiently to disturb the diffusion boundary layers at the surfaces of the oxygen bubbles to facilitate the reaction of the oxygen with the blood hemoglobin and characterized by the production of blood foam comprising an open cellular mixing material means within said chamber downstream of and spaced from said second means having a three dimensional body configuration through which is flowed substantially all of the venous blood and oxygen bubble mixture for providing a plurality of tortuous paths so that said oxygen bubbles are broken down and caused to travel in a plurality of tortuous paths through said blood before escaping from said mixing material means, said mixing material means having a void volume substantially larger than 50% so that said oxygenating chamber (i) provides low impedence to the flow of blood therethrough, (ii) provides relatively low velocities of blood therein, and (iii) can be gravity fed from the patient without any positive pressure pump between the patient and said blood inlet;
• means coupled to said oxygenating chamber for containing the arterialized blood and blood foam produced by said mixing and churning;
• and
• means for defoaming said contained blood and blood foam and producing arterialized whole blood.

A blood oxygenator which requires a low volumetric ratio of oxygen to blood comprising:

• a first clear plastic cyclindrical shell having blood and oxygen inlet means in the lower end thereof;
• a sparger member supported with said first shell at the lower end thereof and coupled to said oxygen inlet means, said sparger member having a plurality of very small interstices for injecting plural oxygen bubbles into blood flowing into said first shell through said blood inlet means;
• a reticulated foam mixing material having a void volume in the range of 85-97% supported within said first cylindrical shell downstream of and spaced above said blood inlet means and sparger member and substantially completely filling the open cross-sectional interior of said first shell along the length of said foam material, said reticulated foam material being free of any anti-foam coating thereon, said blood into which oxygen bubbles have been introduced rising within said shell through said reticulated foam material, said reticulated foam causing said blood and oxygen bubbles to be churned and mixed together sufficiently to disturb the diffusion boundary layers at the surfaces of the oxygen bubbles to facilitate the reaction of the oxygen with the blood hemoglobin, said reticulated foam material having a three dimensional body configuration and a pore size in the range of 5 to 35 pores per inch whereby said oxygen bubbles are both broken down in size and forced to follow a plurality of tortuous paths through said blood;
• a second clear plastic cylindrical shell mounted proximate to said first shell and having an inlet means connected to the upper end thereof;
• a channel for containing the blood and blood foam emerging at the top of said reticulated foam, said channel connecting the upper end of said first shell to the inlet means of said second shell;
• and
• an annular defoamer filter supported within said second shell with the interior of said defoamer filter in communication with the inlet means of second shell, said defoamer filter comprising a reticulated foam material having a pore size in the range of 10 to 50 pores per inch covered with a fine weave filter cloth, all of said arterialized blood and blood foam passing from within the interior of said annular filter to a space between the outer surface of said filter and the entrapped gases pass out of openings in the upper end of said second shell and the whole blood is collected in the bottom thereof.