Abstract: A suction catheter having a vacuum regulator is useful in withdrawing and eliminating undesirable or unwanted fluids from the body. The catheter, which is essentially tubular in shape, has a longitudinal bore extending through its length and is open ended. Also provided is an opening transverse to the longitudinal bore, generally passing through the upper surface of the catheter. The portion of the catheter about this transverse opening is surrounded by a flexible band, such as a rubber band or a plastic material capable of springing back to its original conformation after deformation. The band is preferably oval-shaped with its long sides abutting the sides of the catheter, so that its top, short side is positioned away from the top surface of the catheter when the catheter is not being used or after the band has sprung back to its original conformation.

Abstract: A membrane filter assembly is disclosed which employs at least one filter membrane and includes support means to prevent overflexing or overstressing of the filter membrane when high fluid pressures occur. The membrane support means includes a substantially co-extensive support or back-up surface spaced a small distance from the membrane to allow liquid flow therethrough but to prevent stretching or flexing beyond its elastic limit. Preferably the support surface comprises a second filter membrane in parallel flow relationship with the first to provide high flow rates during normal flow conditions but which flex together during high pressures conditions to mutually support one another and to prevent further flexure of either membrane beyond its elastic limit.

Abstract: A plastic hanger for medical containers or the like is described which, in its normal, unstressed position, lies adjacent the bottom of the container so as not to interfere with setting the container on a flat surface. The hanger is molded separately from the container and sealed or attached to a rib formed on the bottom of the container.

Abstract: A unitary molded injection site comprising a central, needle-receiving portion and a skirt portion may be assembled onto a support tube by temporarily convoluting the skirt portion about the central portion to expose its inner surface; bringing the end of the support tube adjacent to the inner surface; and bringing the skirt portion back toward its original, unstressed configuration, to surround the end portion of the tube in telescoping relation. An advantage of this is that the injection site is positioned on the support tube in relatively unstressed condition. Furthermore, the skirt portion may define on its inner surface a plurality of sealing rings adapted to sealingly bear against the support tube.

Abstract: Metering apparatus for metering the flow of fluid through an administration set includes a peristaltic-type metering pump which repeatedly and progressively compresses a section of vinyl tubing of the administration set to provide a desired flow rate. For improved metering accuracy the fluid is maintained under pressure upline and downline of the metering pump to assist the tubing in becoming fully restored following each compression by the pump. In the illustrated embodiment, upline pressure is provided by a peristaltic-type pressure pump which is operated at a controlled rate to maintain a predetermined upline pressure, and downline pressure is provided by a spring-biased plunger which bears against the tubing downline of the metering pump to partially occlude the tubing.

Abstract: A filter assembly is disclosed for use, in-line, in a medical fluid, e.g., parenteral solution, administration set or the like, to filter the fluid as it is administered to a patient. Hydrophobic and hydrophilic filter membranes are mounted in a parallel-flow relationship within a filter housing, which is sealed except for inlet and outlet ports. The membranes are respectively positioned so that the hydrophobic filter membrane is located above the hydrophilic filter membrane when the filter assembly is suspended in-line in an administration set, permitting any air separated from the fluid by the hydrophilic membrane to migrate upwardly and pass through the hydrophobic membrane instead of accumulating on the surface of and blocking flow through the hydrophilic membrane.

Abstract: A two piece roller clamp is disclosed for regulating the fluid flow rate through plastic tubing by defining the size of the tubing lumen. The clamp includes a U-shaped body with a base and two side walls and a longitudinally movable roller mounted in tracks formed in the side walls. The roller is biased against a roller bearing surface running along the length of the base. Adjacent to the roller bearing surface is a tube compression slot having a lower wall uniformly spaced below the roller. A channel of varying cross-section is provided in the lower wall of the tube compression slot. The roller exerts a uniform, but minimal force on the tubing compressing it against the lower wall of the slot permitting the formation of a lumen defined by the contours of the channel.

Abstract: A thermoplastic composition is disclosed which consists essentially of a major portion of a first poly(ethylene-vinyl acetate) copolymer which contains from 22 to 30 percent by weight of vinyl acetate units and exhibits a melt index as defined herein of 0.5 to 10. A minor portion of a second poly(ethylene-vinyl acetate) copolymer is included which contains from 25 to 40 percent by weight of vinyl acetate units, the second copolymer exhibiting a melt index of 20 to 1000. The resulting formulation exhibits numerous good properties for use in medical devices, coupled with the capacity for radiation sterilization.

Abstract: A controlled volume liquid meter comprises a liquid metering chamber defined between a rigid wall and an opposed flexible membrane wall. Inlet and outlet ports are positioned adjacent the ends of the chamber with the ports defining paths of liquid flow therethrough which are transverse to the direction of liquid flow in the chamber. A pair of plunger members are provided, along with apparatus for alternatingly pressing the plunger members against the membrane wall and inserting the plunger members into the inlet and outlet ports to alternatingly open and close them. In accordance with this invention, the plunger members permit variation of the length of each plunger member, with a spring urging the plunger members to occupy their maximum lengths. As a result of this, the force with which the plunger members press against the membrane wall is limited to a value governed by the spring.

Abstract: A pivoting permanent-magnet armature of an electromagnet forming part of a controller to limit the flow of an intravenous solution through a casette to a patient. The electromagnet may have an E-frame with the permanent magnet pivoting between two positions about a point lying on the extension of the electromagnet's middle leg. In one position, one pole of the permanent magent contacts one side leg of the E-frame to open the casette inlet and maintain the outlet in a closed configuration. In the other position, the permanent magnet's other pole contacts the other side of the E-frame to close the inlet, open the outlet, and allow fluid to flow to the patient. A gap should remain between the permanent magnet and the E-frame's middle leg to avoid their grinding together and a concomitant increase of friction due to the presence of resulting particles. Preventing contact between the permanent magnet and the electromagnet's middle leg also avoids the formation of the magnetic shunt between the two at that point.

Abstract: An airway connector is provided for withdrawing solutions from bottles and comprises a spike having a solution flow passage and an air inlet passage, with both passages opening at the tip of the spike. The spike carries a body member having a filter chamber extending radially outwardly from the spike and being positioned eccentrically with respect to the axis of the spike. The body member defines a portion of the air inlet passage with the air inlet passage portion extending angularly through the body member to communicate with the filter chamber. A hydrophobic filter is located in the filter chamber with the filter having a smaller volume than the volume of the filter chamber to provide an air space communicating with the air inlet passage.

Abstract: A method is disclosed for controlling the dispensing of fluid from a source at a hydrostatic pressure involving the sequential measuring and dispensing of predetermined volumetric increments of fluid from the source of fluid during different ones of a series of time intervals. Apparatus is also provided for controlling the dispensing of fluid, including metering means for receiving a predetermined increment of fluid and for emptying the predetermined increment of fluid, conduit means for delivering fluid from a source of fluid to the metering means, and control means for actuating the metering means between a condition for receiving one predetermined increment of fluid and a condition for emptying the predetermined increment of fluid.

Abstract: A fluid filter is disclosed for use in filtering intravenous fluids as they are administered to a patient. The unique filter employs a normally hydrophobic (water-repellent) depth-type filter element, which has a sufficiently large pore size and volume of pores to permit an adequate gravitational flow of intravenous fluid from an elevated reservoir. Particulate matter is filtered out by the tortuous passageways in the filter element, through which liquid must pass. Due to the relatively large pore size (20 microns or larger) of the filter element, in combination with the normal hydrophobic property, any gas entrained in the liquid also passes through the filter element and does not accumulate on the filter surface to block flow therethrough--so called "air blocking".

Abstract: A plastic slide clamp for tubing is provided which includes a slightly bowed configuration to compensate for the phenomenon of cold flow when plastic tubing is crimped shut by the clamp. In one embodiment, the clamp is provided with an insert member of low friction surface properties which surrounds the crimping slot.

Abstract: A fluid filter is disclosed which separates gas from liquid and vents the separated gas from the filter. The filter includes a vented housing through which the fluid stream passes. Liquid-wetting filter means carried in the housing in the path of the fluid stream permits the passage of liquid only. Gas separated from the fluid is vented through vent opening means which is covered by a liquid-repellent filter to permit the passage of gas only. An automatic, pressure sensitive control means may be used to seal the vent opening means against the entry of ambient air but to automatically release separated gas from the filter. The liquid-repellent filter may be secured to the housing by a mechanical bond between the housing and a fibrous backing carried by the filter, or a continuous band of medical grade tape may be used to attach the filter to the housing.

Abstract: A hermetically sealed container is provided in which a cup-shaped overcap overlies an externally threaded dispensing outlet and is hermetically bonded to the bottle neck. An outer jacket ring is provided to jack the overcap off of the bottle neck when the jacking ring is rotated downwardly. The overcap carries a wiper seal which engages the dispensing outlet to prevent liquid flow out of the dispensing outlet until the overcap is removed. The container closure is tamper-proof in that the overcap cannot be threadedly engaged with the externally threaded dispensing outlet once the overcap has been jacked off the bottle neck.

Abstract: An internally threaded dispensing closure for an externally threaded pharmaceutical container having a pour lip. The top surface of the closure defines a first opening surrounded by an upwardly extending port having a membrane therewithin. The spike of an administration set or the like may be inserted into the port to pierce the membrane. The top surface of the closure also defines a second opening having a hydrophobic filter communicating with the air above the top portion and also below the top portion. A gasket is carried by the underside of the top portion for sealing engagement with the pour lip of the container.

Abstract: An electromagnetic switch which comprises an armature pivotally movable between first and second pivotal positions about a fulcrum positioned between its ends. Magnet means are positioned adjacent each of the armature ends and present opposite polarities outwardly from each end of the armature. Electromagnet core means define arms positioned adjacent the magnet means at each armature end, with the magnet means being each respectively movable toward and away from an arm when pivoting between the first and second pivotal positions. The armature can be moved between the first and second positions by changing the polarity of the electromagnet core means. In accordance with this invention, restraining means engagable with the armature for preventing the armature from pivoting into contact with the electromagnet core means are provided for prevention of noise and for preservation of the life of the magnet means.