Abstract: A defoaming device for separating foam and bubbles from a liquid, such as blood, is disclosed. The device can be used in conjunction with a medical device, such as a membrane oxygenator, for separating air from blood while minimizing blood contact with the antifoam agent used in the device. The device includes a reservoir and a filtering material that does not contain any antifoaming agent. This filtering material is positioned in a lower portion of the reservoir to separate foam and bubbles from the liquid. An element containing an antifoaming agent is positioned in the reservoir above the maximum surface fluid level therein and receives the foam and bubbles that rise from the filtering material. Contact of the liquid with the antifoaming agent is substantially avoided.

Abstract: Autotransfusion apparatus and methods are disclosed for collecting, processing and returning blood to a patient during or after surgery. The processing step of the autotransfusion system comprises sequential rough filtering and filtering of the blood. Filtering is achieved within a single filter housing which includes a first ultrafiltration zone where blood fluids and anticoagulant are separated and removed from red blood cells, a washing zone where washing solution is injected into the remaining concentrated red blood cell solution and a second filtration zone where washing solution, residual blood fluids and anticoagulant are separated and removed from the washed and concentrated red blood cell solution. The filtration includes a rotating disc which creates a shear force upon the blood to prevent clotting and red blood cell build up along the face of filter membranes.

Abstract: A heat exchanger and blood oxgenator apparatus includes a housing having a blood inlet portion, a blood outlet portion, and a housing wall defining an enclosed chamber disposed along a chamber axis between the blood input portion and the blood output portion through which to pass a quantity of blood to be temperature controlled. A heat exchanger tube having an exterior surface and a hollow interior through which to pass a heat exchange medium for purposes of exchanging heat with a quantity of blood brought into contact with the exterior surface, is disposed in a generally helical coil that is mounted within the chamber to encircle the chamber axis. A scalloped inner surface is included on the housing wall to face generally inward toward the heat exchanger tube.

Abstract: A membrane oxygenator includes an upper nested arrangement of a hard shell venous reservoir, a bowl-like defoamer within the reservoir and a heat exchanger coil vertically supported within the defoamer, and includes a membrane oxygenator unit mounted on the bottom of the upper arrangement. The oxygenator unit includes an inlet chamber with a tangential inlet providing swirling blood flow to dislodge air bubbles and centrifuge air to an upper center region of an inlet chamber where gas is exhausted through a vent. A bottom blood outlet chamber of the blood oxygenator unit has a relatively thin vertical cross-sectional area such that priming flow velocity therein discharges all air from the outlet chamber.

Abstract: A liquid-gas bubble separator comrising a container having an inlet for a fluid which includes liquid and gas bubbles, an outlet and upstream and downstream vents. A filter element is provided in the container between the inlet and the outlet. The filter element permits the passage of the liquid and inhibits the passage of the gas bubbles. The filter element is between the upstream and downstream vents so that gas bubbles which do not pass through the filter element can be vented through the upstream vent, and any gas bubbles downstream of the filter element can be vented through the downstream vent. A bypass passage is provided around the filter element. A portion of the filtered fluid is recirculated through the bypass passage to prevent forward flow through the bypass passage when the filter element is clean, and such recirculating flow is terminated when the filter is clogged to a predetermined degree to thereby open the bypass passage for forward flow.

Abstract: A membrane oxygenator includes an upper nested arrangement of a hard shell venous reservoir, a bowl-like defoamer within the reservoir and a heat exchanger coil vertically supported within the defoamer, and includes a membrane oxygenator unit mounted on the bottom of the upper arrangement. The oxygenator unit includes an inlet chamber with a tangential inlet providing swirling blood flow to dislodge air bubbles and centrifuge air to an upper center region of an inlet chamber where gas is exhausted through a vent. A bottom blood outlet chamber of the blood oxygenator unit has a relatively thin vertical cross-sectional area such that priming flow velocity therein discharges all air from the outlet chamber.

Abstract: Stress cracking of polycarbonate parts during prolonged storage while assembled with plasticized polyvinyl tubing is greatly reduced by using tubing in which tri-2-ethylhexyl trimellitate is the predominant or sole primary plasticizer.

Abstract: A yoke shaped collapsible blood reservoir having first and second yoke legs joined by a yoke midsection. A filter element is positioned in the yoke midsection and across the blood flow path between an inlet at the base of the first yoke leg and a blood outlet at the base of the second yoke leg. An angular blood inlet and a gradual increase in cross-sectional area from the blood inlet to the yoke midsection decreases turbulence and assists in bubble separation.

Abstract: This invention relates to a blood filter assembly in which blood enters at the bottom end of the assembly, is directed in spirally upward path and then passes through a filter medium. After passing through the filter medium, the blood flows downwardly out of an outlet in the bottom end of the assembly. A gas vent is provided at the top end of the assembly. In its preferred embodiment, the outer shell of the assembly tapers from the bottom end to a narrower diameter top end, the filter medium is generally shaped in the form of a cylindrical tube and a core member is provided radially inwardly of said filter medium and spaced therefrom. This filter assembly is particularly useful for the removal of particulate matter, gas and other foreign materials from blood.

Abstract: A blood oxygenator containing a means for combining oxygen-containing gas with liquid blood, the oxygenator having an outer shell portion rotatably joined to a cap portion. Preferably the cap portion includes at least one blood inlet together with an oxygen-containing gas inlet while the outer shell portion contains at least one oxygenated blood outlet and the rotatable joint between said outer shell portion and said cap portion is in venting communication with the exterior of the blood oxygenator.