Abstract: A pre-slit injection site (34) includes a housing (40) with a flow path therethrough. A first end (42) of the housing (40) carries a pre-slit septum (52). One form of a blunt cannula (98), usable with the injection site (34), carries a locking member (100). When the pre-slit injection site (34) slidably receives the blunt cannula (98), the locking member (100) latches to the injection site (34) and creates a mechanically coupled unit. Another form of the cannula (280) includes a tube having a tapered distal end region (298) and having elongate discharge slots (294) for reducing contact surface area and for directing the flow laterally out of the cannula. The cannula may also include a rounded lead post (330), an annular barb (394), and axially oriented grooves (268). A blood sampling system utilizing an in-line pre-slit injetion site (492) and a shielded blunt cannula (512).

Abstract: A membrane oxygenator having a gas pressure relief valve operable to release gas when the gas pressure in the oxygenator exceeds a predetermined level. Generally, the membrane oxygenator includes a housing in which is mounted a gas-permeable, liquid-impermeable membrane, i.e. a bundle of microporous hollow fibers. This membrane defines separate oxygen enrichable fluid and gas flow pathways. The housing also includes both gas and oxygen enrichable fluid inlet and outlet ports communicating with respective opposite ends of the gas and oxygen enrichable fluid flow pathways. The gas pressure relief valve communicates with the gas flow pathway.

Abstract: A device including an integrally formed membrane oxygenator and heat exchange device positioned in a single housing. The device includes a thermally conductive body formed with a plurality of blood pathways on its surface, and a gas permeable membrane, or membranes positioned in the housing in substantial contact with the heat exchange body to cover or lie within a portion of each of the pathways. The membrane defines a gas pathway separate from the blood pathway through which a gas is directed. The blood is directed through the individual blood pathways. The device also includes various ports and passageways for delivering the blood to the individual channels, and for collecting and removing the blood from the device.

Abstract: A blood oxygenator having a defoaming device for separating foam and bubbles from a liquid, such as blood, is disclosed. The defoaming device of the oxygenator is designed for separating air from blood while minimizing blood contact with the antifoam agent used in the device. In a first embodiment, 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. In a second embodiment, an element containing an antifoaming agent is positioned in the reservoir within the fluid therein.

Abstract: An apparatus and method for providing optical switching or color selection capability uses cholesteric liquid crystals which reflect and transmit circularly polarized light and a variable wave retarder element together with phase reversing mirrors which recapture and recombine the reflected circularly polarized light. With the retarder element in a first state, first orientation circularly polarized light is completely transmitted and second orientation circularly polarized light is redirected. Alternatively, a color selection assembly is provided through the use of a combination of cholesteric light crystals in which light of a first color is given a first polarization orientation and light of a second color is given a second polarization orientation. Depending upon the state of the retarder either the first or second color is transmitted to a desired target.

Abstract: An adaptive filter concentrate flow control system and method includes a filter system, a pumping system driving feed fluid, concentrate and filtrate flowing through the filter system and a flow control system controlling the pumping system to maintain optimum filtrate flow rates or minimum feed flow rates along a control surface in a three dimensional transmembrane pressure--feed fluid rate--filtrate flow rate space. Actual sensed operating point data is used to locate the control surface so as to assure an optimized filtrate flow rate or minimized feed flow rate at which reversible blocking of the membrane has begun to occur without irreversible blocking or plugging. The system is advantageously employed to control and maximize the flow of plasma in a plasmapheresis system or to minimize the rate at which blood is withdrawn from a donor and introduced into the system while achieving a fixed rate of plasma flow.

Abstract: A blood reservoir device comprising a generally flexible blood collection chamber having an inlet portion and a main portion. The inlet portion is preferably sized and configured such that blood entering the inlet portion will avoid turbulence and will undergo generally laminar flow through the inlet portion, into the main portion of the chamber. A vent tube is provided for venting coalesced or collected gas bubbles from the top edge of the chamber. Additionally, one or more filter elements may be positioned within the chamber to further facilitate removal of air bubbles from blood passing through the chamber.

Abstract: A system and method for cleaning contaminants from shed blood to enable reinfusion of a cell concentrate in the patient employs successive rotary membrane filtering stages in which Taylor vortices are generated. Shed blood led into the first rotary membrane stage is filtered to produce a hematocrit in the range of 50-60 with some of the waste matter being removed. The intermediate cell concentrate is passed to the second filter stage where further waste matter is initially extracted. At any intermediate region, however, a major amount of wash solution is fed into the concentrate and effectively mixed therein. In the remaining length of the second filter stage, waste matter is entrained in the wash solution and both waste and wash solution are filtered out to provide a cell concentrate from which the great majority of contaminants have been removed.

Abstract: A non thrombogenic quaternary ammonium-heparin complex coating for a medical article comprising an amount of at least 50% by weight of one or more cationic quaternary ammonium organic salts having the following formula: ##STR1## Wherein R.sub.1 is an alkyl group having from about 14 to about 22 carbons;R.sub.2 is an alkyl group having from about 1 to about five carbons;R.sub.3 is an alkyl group having from about 1 to about five carbons.