Abstract: A biomedical polymer has a substantially linear base polymer; and branched polyethylene oxide covalently bonded to the base polymer as surface active end groups. The branched polyethylene oxide has at least two, more particularly at least four, and still more particularly at least six branches. Suitable base polymers include epoxies, polyurethanes, polyurethane copolymers, fluoropolymers, polyolefins and silicone rubbers. Biologically active agents may be attached to the branched polyethylene oxide. Suitable biologically active agents include microbial peptide agents, detergents, non-steroidal anti-inflammatory drugs, cations, amine-containing organosilicones, diphosphonates, fatty acids, fatty acid salts, heparin and glucocorticosteroids. The biological polymer may be used as a casing for a medical unit of an implantable medical device, such as a pacemaker. In this case, the casing at least partially encloses the medical unit.

Abstract: A biostable polymeric substrate of an implantable medical device unit includes a demand-release bioactive composition including one or more bioactive agents covalently bound to surface-modifying end groups of the substrate. Certain cellular activities, in proximity to the polymeric substrate, release substances reacting with the end groups such that the end groups release the one or more bioactive agents, which modify the certain cellular activities.

Abstract: An implantable medical device that includes a lead body extending from a proximal end to a distal end, a plurality of conductors extending between the proximal end and the distal end of the lead body, and an insulative layer formed of a hydrolytically stable polyimide material surrounding the plurality of conductors. In one embodiment, the hydrolytically stable polyimide material is an SI polyimide material.

Abstract: A biomedical polymer has a substantially linear base polymer; and branched polyethylene oxide covalently bonded to the base polymer as surface active end groups. The branched polyethylene oxide has at least two, more particularly at least four, and still more particularly at least six branches. Suitable base polymers include epoxies, polyurethanes, polyurethane copolymers, fluoropolymers, polyolefins and silicone rubbers. Biologically active agents may be attached to the branched polyethylene oxide. Suitable biologically active agents include microbial peptide agents, detergents, nonsteroidal anti-inflammatory drugs, cations, amine-containing organosilicones, diphosphonates, fatty acids, fatty acid salts, heparin and glucocorticosteroids. The biological polymer may be used as a casing for a medical unit of an implantable medical device, such as a pacemaker. In this case, the casing at least partially encloses the medical unit.

Abstract: An implantable medical device, perhaps a pacemaker lead, has a medical unit and a casing at least partially enclosing the medical unit. The casing is formed of a base polymer having surface modifying pendant groups formed of an acrylamide polymer or an acrylamide copolymer, perhaps polyisopropyl acrylamide. The base polymer may be a polyurethane, polyimide, fluoropolymer or polyolefin, for example.

Abstract: A laminated blade assembly including a stationary blade and a pair of insulation supports and a movable blade and a pair of insulation supports with each blade sandwiched between a pair of supports. Semi-circular grooves formed in the insulation supports and smaller semi-circular grooves formed in blades in alignment with the insulation support grooves creating circular grooves to support and cut the insulation when the stationary and movable blades come together. The support semi-circular grooves of one of the stationary and movable insulation supports are located with their peripheries tangent to a straight line which is not parallel to the center lines of the blade semi-circular grooves.

Abstract: An implantable lead having a silicone rubber lead body which has a reduced coefficient of friction on an internal or external surface. The reduction in coefficient of friction is accomplished by extruding a tubular lead body to define a plurality of small parallel longitudinally extending grooves on the inner or outer surface of the lead body. The grooves may be formed by means of a die having inwardly or outwardly directed projections that form the grooves during the extrusion process. The formation of the grooves during extrusion provides a lead body having a lower coefficient of friction without the necessity of additional manufacturing process steps and without additional manufacturing costs.

Abstract: This invention relates to an apparatus and a method for improving slip characteristics on the surface of a polymeric material, such as an outer surface, inner surface, or both of polymeric tubing.

Abstract: Polymeric tubing having an outer surface with a reduced coefficient of friction. The outer surface is treated by an exposure to a plasma glow discharge in the presence of an inert gas, and by deposition of a monomer during exposure to the plasma glow discharge for a time sufficient to modify the slip characteristics of the surface of the tube. The tube is preferably exposed to plasma glow discharge for a time sufficient to reduce the coefficient of friction by at least 70%. The tubing may be fabricated of silicone rubber, and the monomer deposited may be N-vinyl-2-pyrrolidone.

Abstract: An implantable medical device has an electrode lead having an outer surface of a polymeric material which has been treated in an inert gas atmosphere by a glow discharge to deposit a monomer substance thereon to produce an outer surface lower in resistance to movement within the body tissue of a patient than untreated material.

Abstract: A medical electrical lead and a reinforced silicone elastomer used therein. The silicone elastomer used therein is preferably made from a novel silica reinforced polysiloxane material, which after vulcanization by cross-linking exhibits improved mechanical properties. The medical electrical lead features a an electrode at a distal end thereof, a connector at a proximal end thereof and an elongated electrical conductor extending between the electrode and the connector, the conductor in electrical contact with the electrode at a distal end and in electrical contact with the connector at a proximal end, the conductor comprised of a plurality of wires or wire bundles wound in a multifilar coil configuration.

Abstract: A medical electrical lead having an elongated lead body carrying a conductor therein, the lead body being formed of an inner sleeve of a first, relatively more rigid plastic and an outer sheath of a second, relatively less rigid plastic, the inner sleeve having a tubular portion and having outwardly extending helical ridges extending along its length, the ridges having lateral wall surfaces extending radially from the tubular portion and an outer sheath over the inner sleeve and in contact with the lateral wall surfaces of the inner sleeve. A fixation helix may be mounted at the distal end of the lead body and a conductor, which is also rotatable relative to the lead body may be located within the inner, tubular sleeve. Conductors may also be located between the ridges of the inner sleeve, embedded in the outer sheath.

Abstract: A medical electrical lead and a reinforced silicone elastomer used therein. The silicone elastomer used therein is preferably made from a novel silica reinforced polysiloxane material, which after vulcanization by cross-linking exhibits improved mechanical properties. The medical electrical lead features a an electrode at a distal end thereof, a connector at a proximal end thereof and an elongated electrical conductor extending between the electrode and the connector, the conductor in electrical contact with the electrode at a distal end and in electrical contact with the connector at a proximal end, the conductor comprised of a plurality of wires or wire bundles wound in a multifilar coil configuration.

Abstract: A medical electrical lead and a reinforced silicone elastomer used therein. The silicone elastomer used therein is preferably made from a novel silica reinforced polysiloxane material, which after vulcanization by cross-linking exhibits improved mechanical properties. The medical electrical lead features a an electrode at a distal end thereof, a connector at a proximal end thereof and an elongated electrical conductor extending between the electrode and the connector, the conductor in electrical contact with the electrode at a distal end and in electrical contact with the connector at a proximal end, the conductor comprised of a plurality of wires or wire bundles wound in a multifilar coil configuration.

Abstract: A lead insulator which provides resistance to tearing and/or abrasion for implantable flexible electrical lead insulators having a body of silicone elastomer material. A relatively thin layer of a second silicone is applied as an overcoat to a more substantial primary or first insulator body. The second silicone is more resistant to tearing and/or abrasion than the elastomer comprising the body of the insulator. Because tearing and/or abrasion are surface phenomena, only a relatively thin layer of the second material is particularly required and the mechanical properties of the primary material will determine the overall mechanical properties of the lead insulatior per se.

Abstract: A biomedical lead conductor body formed of a coiled wire conductor that is sheathed loosely within a coiled insulative sheath of biocompatible and biostable material allowing a gap or space to be present between the exterior surface of the coiled wire conductor and the adjacent interior surface of the insulative sheath. The coiled insulative sheath is loosely fitted around the coiled wire conductor in order to compensate for defects in the coiled insulative sheath by spreading any corrosion of the wire that may take place because of the defect away from the site of a defect and along the surface of the coiled wire conductor. The lead body is incorporated into unipolar, bipolar or multi-polar biomedical leads having single filar coil windings, or multi-filar coil windings that may be redundantly electrically connected. The coiled wire conductors and coiled insulative sheaths may be parallel-wound and/or coaxially wound within the outer lead body insulative sheath.

Abstract: The present invention provides resistance to degradation from environmental stress cracking (ESC) and metal ion induced oxidation (MIO) for implantable, flexible pacing lead insulators having a body of polyether polyurethane elastomer material. A thin layer of a second polyurethane elastomer is applied as an overcoat to the lead insulator body. The second polyurethane is more resistant to ESC and MIO than the elastomer comprising the body of the insulator. Because ESC and MIO are surface phenomina, only a thin layer of the second material is required and the mechanical properties of the base material will determine the overall mechanical properties of the lead insulator.

Abstract: The present invention provides resistance to degradation from environmental stress cracking (ESC) and metal ion induced oxidation (MIO) for implantable, flexible pacing lead insulators having a body of polyether polyurethane elastomer material. A thin layer of a second polyurethane elastomer is applied as an overcoat to the lead insulator body. The second polyurethane is more resistant to ESC and MIO than the elastomer comprising the body of the insulator. Because ESC and MIO are surface phenomina, only a thin layer of the second material is required and the mechanical properties of the base material will determine the overall mechanical properties of the lead insulator.

Abstract: A vent cap for a heat treating furnace provides bidirectional pressure relief. The cap is weighted and balanced over the furnace vent such that the vent is closed as long as the furnace has a slightly positive internal pressure. If the internal pressure exceeds a preselected upper limit the cap opens the vent to relieve the overpressure. The vent cap has a controlled inlet which opens to equalize the pressure differential if the internal pressure falls below a preselected lower limit below the ambient pressure outside the furnace. Such controlled equalization prevents the formation of undesirable combustible mixtures of air and treating gas in the furnace.