Abstract: An apparatus for warming blood and other parenteral fluids as they are infused through a disposable flow system includes a pair of heating elements which heat the blood as it passes through a warming bag provided in the flow system. The heating elements are recurringly switched on and off with a duty cycle dependent on both the temperature of the blood at the output of the warming bag and the temperature differential between the output and input of the bag to maintain the blood at a predetermined temperature independent of flow rate. A digital display and monitoring circuit provides a highly accurate digital indication of blood temperature and interrupts the application of power to the heating elements in the event the temperature exceeds a predetermined maximum level.

Abstract: Photometric apparatus and method for determining the absorbance ratio, in a sample, of two different wavelength lights. A first light is given a reference intensity and is passed through the sample. A second light is passed through the sample and its intensity is varied so that the intensity of the second light that has passed through the sample is equal to the intensity of the first light that has passed through the sample. When these intensities are equal, the intensity of the second light is detected in a state wherein it has not passed through the sample, resulting in an equivalent to the ratio of the absorbance in the sample of the second light and the first light.

Abstract: An openable seal member for a container includes a tube extending across the sealed area of the container for flow communication between the interior and exterior thereof. A flexible plastic pocket member seals and encloses the outer end of the tube. Tear means are provided for opening the pocket member, comprising a circumferential line of tearing weakness positioned about the pocket member in transverse relation to the longitudinal axis of the tube. In accordance with this invention, a flexible generally conical portion is positioned between the outer end of the tube and the tear means, with the conical portion diverging outwardly and constituting an inner portion of the pocket member, to define upon opening of the seal member, an enlarged, protective area surrounding the outer end of the bore of the tube.

Abstract: Flexible coextruded tubing having an outer portion (14) of polyvinyl chloride plastic containing a minor amount of intimately mixed silicone oil and having an inner portion (12) of plastic free of silicone oil.

Abstract: An end of thermoplastic tubing which is exposed to a temperature capable of causing dimensional distortion of the tubing end may be maintained by enclosing the tubing end with a tubular end cap. The end cap defines an inner member projecting axially into the bore of the tubing end, with the inner member defining an outer diameter of essentially the diameter of the bore of the tubing end, so that the dimensional integrity of the tubing end is maintained during the heating step to thereafter sealingly receive a luer.

Abstract: In a flexible tube, for example tubing for connecting blood bags, valve means are provided which comprises a tubular portion having a closed end, and an elongated, generally rigid member carried on the exterior of the closed end and positioned within the flexible tube. Frangible means are provided to permit the opening of the closed end by manual manipulation of the elongated member from outside of the flexible tube. The elongated, rigid member is adapted to fit in sealing relationship within the tubular portion after the opening of the closed end, to permit resealing of the valve.

Abstract: Sealed, flexible containers may be manufactured with a sterile, openable seal member by inserting part of a thermoplastic tube between a seal in such a manner as to permit the tube to communicate across the seal. In manufacture, the outer end of the tube may be enclosed with a thermoplastic pocket member having open inner and outer ends. A mandrel is inserted through the outer end of the pocket member and the tube. The thermoplastic sheet members, tube, and inner end of the pocket member are sealed together. Following this, the mandrel is withdrawn through the outer end of the pocket member which outer end is then also sealed, for a sterile seal, if desired. A novel design for a container seal is also disclosed.

Abstract: Process and apparatus for weighing material being collected. In the illustrative embodiment, plasma that has been separated from whole blood is collected. The tare weight is sensed and the weight of the material being collected is sensed. Pulses are provided in frequency proportion to the sensed weight. The tare weight pulses are counted and stored. A net weight counter is set with a predetermined count corresponding to the maximum amount of plasma to be collected. A measure weight signal reverses the tare weight count with the net weight counter being inhibited until the tare weight count reversal has been completed. Once the tare weight count reversal is completed, the net weight counter is operative to count the sensed weight pulses. A completion signal is provided when the predetermined count has been decremented to zero.

Abstract: Blood-compatible, chlorine-free polymers such as a flexible, non-toxic, sterilizable polyester plastic formulation may contain from 5 to 70 percent by weight of a blood-extractable plasticizer such as di-2-ethylhexyladipate, to cause blood which is stored in contact with the polymer to exhibit a surprisingly low hemolysis rate when compared with corresponding polymers which are free of the plasticizer. Accordingly, blood bags, tubing and other medical blood-contacting devices may be advantageously made from these polymers.

Abstract: An aqueous red cell storage solution for packed cells which permits removal of essentially all plasma from a unit of blood, followed by reconstitution of the packed cells of the unit in preferably about 80 to 150 ml. of solution for improved cell viability on long term storage. The red cell storage solution contains adenine, glucose or fructose, sodium chloride, and mannitol.

Abstract: Improved valves for use within medical devices include a valve body having a plurality of fluid-passing openings, a resilient liner having raised portions defining flow paths, and a plug having a configuration generally complementary to that of the liner, at least a portion of the plug generally overlying the liner for maintaining raised portions of the liner in sealing engagement with the valve body in a manner that enhances valve integrity as to leakage while simultaneously improving valve operation by providing easy rotation of the plug and liner with respect to the valve body. The in-use illustrated embodiment of the valve is on a urine drainage device, the valve being interposed between a relatively rigid urine flow monitoring and measuring chamber and a flexible collection receptacle, the valve permitting flow path selections for retaining urine within the measuring chamber or for flowing urine therefrom into the flexible collection receptacle or through a sampling port.

Abstract: A sealed, sterile connection may be provided between a pair or more of containers having transparent, flexible, thermoplastic sealed walls, each of which contains an opaque, relatively rigid, hollow sealing member in the general shape of a truncated cone, open at both ends. The containers are brought together into facing contact, and the hollow sealing members are nested together with portions of the transparent walls of the containers positioned therebetween. The nested, sealing member cones are irradiated with infrared or the like through the transparent container walls to heat the nested sealing members. As a result of this, heat is conducted to the portions of the transparent walls between the nested sealing members, to seal the portions of the transparent walls together in an annular area between the sealing means. A portion of the transparent walls retained in the nested sealing members may then be torn away to make a sterile connection between the two containers.

Abstract: Blood plasma is frozen in a sealed, flexible, collapsible container which defines an inlet at one end and a shoulder portion surrounding the inlet. The container tapers from the shoulder portion to a generally flat configuration at its end opposite the one end. After the freezing step, the shoulder portion is cut away from the container to define a cut end. Thereafter, the frozen plasma may be removed from the container in frozen form by squeezing the wall of the tapered container to expel the frozen plasma out of the cut end of the container.

Abstract: The apparatus includes a peristaltic pump for withdrawing whole blood from a patient, a device for centrifuging the blood to separate plasma from the whole blood, a plasma treatment chamber for receiving the plasma, a vehicle positioned within the chamber and having an immuno-adsorbent agent fixed thereon to interact and bond with an immunological reactant carried by the plasma that is passed through the chamber for removing the immunological reactant from the plasma, tubing connected to recombine the substantially immunological reactant free plasma with the remainder of the whole blood and a peristaltic pump for returning the recombined whole blood to the patient. According to the present invention the plasma treatment chamber has a variable volume so that the chamber can be used for treating sequentially different quantities of plasma.

Abstract: The method and apparatus are useful in forming a parison which has a varying wall thickness and an outer diameter larger than the outer diameter of the annular outlet orifice from which the parison is extruded. Such a parison is obtained by adding additional molten thermoplastic material to the parison while extruding the same to vary the thickness of portions of the parison. The additional molten material is directed radially outwardly from the axis of the parison to increase the wall thickness and to increase the swell of the parison which is defined as the ratio of the inner diameter of the parison to the outer diameter of the outlet orifice. Also the ratio of the outer diameter of the parison to the inner diameter of a mold in which the parison is blowmolded into a container is reduced permitting a larger container to be formed from the thicker portion of the parison while having a small entrance opening formed from a thin wall portion of the parison.

Abstract: The apparatus includes a peristaltic pump for withdrawing whole blood from a patient, a device for centrifuging the blood to separate plasma from the whole blood, a plasma treatment chamber for receiving the plasma, a vehicle positioned within the chamber and having an immunoadsorbent agent fixed thereon to interact and bond with an immunological reactant carried by the plasma that is passed through the chamber for removing the immunological reactant from the plasma, tubings connected to recombine the substantially immunological reactant free plasma with the remainder of the whole blood and a peristaltic pump for returning the recombined whole blood to the patient. In one plasma treatment chamber, the vehicle is defined by a spiral coiled membrane which has an immunoadsorbent agent fixed thereon. Each convolution of the spiral is spaced from an adjacent convolution and the coil is positioned within the chamber so that plasma flows through the space between the convolutions of the spiral coiled membrane.

Abstract: The method for bonding a plastic tubing to a metal needle includes the steps of coating the inner end of the needle with a cement, inserting the coated inner end of the needle within the outer end portion of a plastic tubing and applying a radiofrequency current across the plastic tubing around the inner end of the needle to heat seal the plastic tubing to the inner end of the needle.

Abstract: The nose seal assembly is utilized in a centrifugal chemical analysis apparatus wherein compressed air and wash water tubings are coupled through the assembly to the nose of an open ended hollow shaft for providing a seal between the nose and the assembly upon relative rotational movement therebetween. The assembly comprises a hollow bushing to which is clamped an annular web pad which is made of Nylatron NSB .RTM. having a high pressure x velocity (PV) factor and a low coefficient of friction. The assembly further includes a heat dissipation disc to which the wear pad is clamped and an elastomeric washer which is cemented to and between the bushing and the heat dissipation disc and which is designed to provide sufficient "give" to enable the assembly to maintain a good seal when the wear surface of the wear pad is not coplanar with the plane of the nose. Also, the nose has a hemi-toroid configuration to enhance sealing with, and to reduce wear of, the wear pad.

Abstract: A membrane diffusion device, such as a membrane oxygenator, is disclosed which comprises a stack of flat membrane wall pairs and flat membrane supports in alternating, interleaving relation. The casing includes a pair of opposed sidewalls that are substantially parallel to flat sides of the stack, and a pair of substantially vertical crimps are formed on each of the sidewalls to provide external compression on the end portions of the stack.