Abstract: We describe connectors for safely and conveniently injecting measured doses of sterile liquid medications into a patient via one or more infusion ports in intravenous access assemblies. Each connector comprises a tubular injector divided by a rigid septum which holds a hollow needle sharp on each end safely recessed in a leading and in a trailing chamber. The leading chamber snugly holds the trailing limb and penetrable cap of an inserted standard infusion port. The trailing recess snugly holds the leading end of a cartridge with a leading penetrable diaphragm, a bore containing liquid medication, a cartridge piston and trailing bore suitable for insertion of a separate cartridge plunger having markers for measuring doses delivered; or, alternatively, the pentrable cap and trailing limb of second similar infusion port attached by trailing tubing to a large measured volume infusion source.

Abstract: In accordance with the invention, there are provided medical devices with incorporated shape memory systems that allow a polymeric medical device to be inserted in a first conformation or configuration and revert to a second conformation or configuration. The invention is useful in allowing the easy insertion or implantation of a device followed by expansion of the device in order to be retained without expulsion from a body cavity, for example. In another aspect of the invention there is provided a medical device, such as a ureteral stent, that includes comprising an elongated member having a proximal end portion and a distal end portion joined by a body portion. The elongated member has an initial outer diameter. A retention construction serves for retaining the member within a bodily cavity. The member is formulated of a physiologically acceptable polymer capable of hydrating and expanding from the initial member outer diameter to form a final member outer diameter.

Abstract: An apparatus is provided for facilitating substantially bloodless insertion into and withdrawal from a patient's body of a longitudinal member having a proximal end portion and having a distal end portion which is adapted to extend into the patient's body. The apparatus comprises a longitudinally extending sleeve having proximal and distal end portions and defining a lumen extending there along. The longitudinal member is positioned along the lumen. The sleeve has a line extending longitudinally along it which is either split or splittable so that the sleeve can be separated along the line for removal from about the longitudinal member while the distal end portion of the longitudinal member remains extended into the patient. A valve structure serves for preventing blood flow through the lumen. An access is present for allowing substantially bloodless insertion and withdrawal of the longitudinal member through the lumen.

Abstract: A ureteral stent comprising an elongated member having a proximal end portion and a distal end portion joined by a body portion. The elongated member has an initial outer diameter. A retention construction serves for retaining the member within the ureter. The member is formulated of a physiologically acceptable polymer capable of hydrating and expanding from the initial member outer diameter to form a final member outer diameter. The stent can assume differing shapes and can exhibit different degrees of softening at different places along its length.

Abstract: An apparatus is provided for facilitating substantially bloodless insertion into and withdrawal from a patient's body of a longitudinal member having a proximal end portion and having a distal end portion which is adapted to extend into the patient's body. The apparatus comprises a longitudinally extending sleeve having proximal and distal end portions and defining a lumen extending there along. The longitudinal member is positioned along the lumen. The sleeve has a line extending longitudinally along it which is either split or splittable so that the sleeve can be separated along the line for removal from about the longitudinal member while the distal end portion of the longitudinal member remains extended into the patient. A valve structure serves for preventing blood flow through the lumen. An access is present for allowing substantially bloodless insertion and withdrawal of the longitudinal member through the lumen.

Abstract: A swellable cannula is formed of concentric inner and outer hydrophilic and substantially non-hydrophilic layer structures. The hydrophilic layer structure comprises at least 2/3rds of the cross-sectional area of the wall of the cannula. The substantially non-hydrophilic layer structure is either substantially water impermeable or allows water to pass through at a controlled rate. The substantially non-hydrophilic layer structure may also control the diffusion of medicaments. The cannula has controlled softenability and swellability characteristics.

Abstract: The invention relates to a catheter assembly comprising a cannula, needle and catheter inserter wherein the inserter is in slidable relationship to the cannula and wherein the inserter or other device also serves to selectively restrict the cannula and needle from sliding relative to the inserter. The cannula comprises a material which, when inserted into the body of a living subject, softens and/or swells and has a tensile energy to break of at least about 700 N-cm/cm.sup.3 and a 2.5% Secant modulus of less than about 7,000 N/cm.sup.2. The invention also relates to a method of inserting a cannula into a living subject using an inserter which is positioned such that the desired length of cannula for initial insertion extends beyond the inserter. The method also relates to further inserting the cannula into the living subject after initial insertion of the cannula.

Abstract: Self-regulating articles, particularly heaters, containing two spaced-apart elongate electrodes which are joined together by a melt-extruded element composed of a conductive polymer. The conductive polymer is a dispersion of carbon black in a crystalline polymer, has a resistivity at room temperature of R ohm-cm, and contains L % by weight of carbon black, L being not greater than about 15, and L and R being such that2L+5 log.sub.10 R.ltoreq.45.

Abstract: A tubular cannula has distal and proximal end portions, a central passageway from the distal end portion of the proximal portion and a transition section connecting the distal and proximal end portions. The proximal end portion has larger inner and outer diamters and has thicker walls than does the distal end portion. The diameter difference and thickness are effectuated in a gradual manner in a transition section. The cannula is constructed of a material that softens on being inserted into a living body and/or contacted with an aqueous medium. The cannula combines kink resistance external of the living body with the advantages of a softening and generally swellable catheter.

Abstract: A catheter assembly comprises a cannula having proximal and distal end portions and a longitudinal duct having an initial inner cross-section. The duct increases in cross-section when at least a part of the distal end portion of the cannula is inserted into a body of a living subject and maintained in contact with the body, and/or when the duct is contacted by an aqueous liquid, for a period of time sufficient for an enlarged duct cross-section to form. A hub has a passageway from a first to a second end thereof. The passageway has a cross-sectional area throughout at least substantially equal to 125% of the initial inner cross-section of the duct. A proximal end portion of the cannula is attached to the first end of the hub with a passageway through the hub in flow communication with the duct in the proximal end portion of the cannula.

Abstract: The invention relates to a catheter assembly comprising a cannula, needle and catheter inserter wherein the inserter is in slidable relationship to the cannula and wherein the inserter or other device also serves to selectively restrict the cannula and needle from sliding relative to the inserter. The restricted movement is caused by a portion of the cannula swelling when contacted by a liquid. The invention also relates to a method of inserting a cannula into a living subject using an inserter which is positioned such that the desired length of cannula for initial insertion extends beyond the inserter. The method also relates to further inserting the cannula into the living subject after initial insertion of the cannula.

Abstract: Electrical devices comprising a layer of a PTC conductive polymer and a sheet electrode in contact with each face of the PTC layer. The electrodes extend to the sides of the layer and the sides of the layer are concave, and this results in improved performance. Preferred devices are circuit control devices which protect a circuit from increases in current resulting from a fault.

Abstract: An electrical switch includes a body having one open end exposed for adaptation of a pyrotechnic cartridge and the other end sealed by the base of a pin type connector assembly having short conductive pins and elongated conductive pins with relief areas containing insulative material. The pins are inserted into the body cavity. A conductive grounding plate or plates have tabs which bite into the pins and connect selected pins in a first operational state. A plunger having fracturable bosses is located adjacent the contact plate. Upon activation of a pyrotechnic cartridge, pressure is applied to the plunger, causing fracture of the bosses and resulting in the displacement of the plunger to move the contact plate to a different position thereby changing the number of closed circuits.

Abstract: Method and apparatus for continuous manufacture of a laminate comprising a layer of a conductive polymer and at least one electrode. A tape electrode and a heat-softened conductive polymer are fed simultaneously through an elongate aperture of substantially closed cross-section formed by a plurality of rollers, whereby there is produced a laminate in which the conductive polymer layer has a controlled cross-section. Preferably the electrode has a plurality of openings therein and is fed through the aperture so that there is at least one point on the electrode, as it passes through the aperture, which coincides with an angle which is formed by two of said rollers and which is at most 90.degree.. Particularly good results are obtained when the roller which contacts the electrode has a plurality of indentations therein, so that conductive polymer not only penetrates into the openings in the electrode but also passes through those openings which overlie the indentations in the roller.

Abstract: Electrical devices comprise a conductive polymer element and, in electrical contact therewith, a flame-sprayed layer of a metal or other highly conductive material. Electrical leads can readily be attached to the flame-sprayed layer. Particularly valuable devices are those in which at least part of the conductive polymer element is a PTC or NTC conductive polymer. The flame-sprayed layer can be formed directly by flame-spraying a suitable material onto the device, or by flame-spraying the material onto a carrier and then laminating the layer, on the carrier, to the device.

Abstract: Described herein are self-regulating conductive articles comprised of an extruded length of polymeric material containing not more than about 15% by weight conductive carbon black, the resistivity of the extrudate following prolonged exposure to temperatures in excess of the crystalline melting point or range of the polymeric matrix in which the black content satisfies the equation:2L+5 log.sub.10 R.ltoreq.45.Wherein L is percent by weight black and R is resistivity of the extrudate expressed in ohm-cm. The articles exhibit room temperature resistivity in the range from about 5 to 100,000 ohm-cm and may be employed, e.g., in heat tracing and thermostating applications.

Abstract: Method and apparatus for continuous manufacture of a laminate comprising a layer of a conductive polymer and at least one electrode. A tape electrode and a heat-softened conductive polymer are fed simultaneously through an elongate aperture of substantially closed cross-section formed by a plurality of rollers, whereby there is produced a laminate in which the conductive polymer layer has a controlled cross-section. Preferably the electrode has a plurality of openings therein and is fed through the aperture so that there is at least one point on the electrode, as it passes through the aperture, which coincides with an angle which is formed by two of said rollers and which is at most 90.degree.. Particularly good results are obtained when the roller which contacts the electrode has a plurality of indentations therein, so that conductive polymer not only penetrates into the openings in the electrode but also passes through those openings which overlie the indentations in the roller.

Abstract: An expansion joint for metallic foil strip heaters encasing resistive heating elements comprised of a bend formed in the metallic foil strips. The expansion joint is formed by use of a tool for passing a roller in the tool handle over a rigid forming support affixed to the tool bottom forming plate with the metallic foil strip heater placed between the roller and the forming support. The tool is then removed and a flexible metal support hose is affixed to the object to be heated with the bend in the metallic foil strips placed over this support hose. The bend is then affixed to the object to be heated on either side of the support hose.