Abstract: A balloon catheter includes a sheath surrounding the balloon, the sheath having a longitudinal line of weakness and a drug-containing viscous matrix material intermediate between the balloon and the sheath such that when the balloon is positioned and inflated in the body lumen it causes the sheath to burst at the line of weakness and release viscous matrix material onto said body lumen. The device provides accurate placement of the dosage required at the location in need of treatment. The catheter is especially useful in balloon angioplasty procedures.

Abstract: An improved spacer material for improving the biocompatibility of a biomaterial and a method for making it in which a polyalkylimine is covalently attached to an aminated substrate and combined with a crosslinking agent which is at least difunctional in aldehyde groups. The polyalkylizine can be, for example, polyethyleneimine and the crosslinking agent can be, for example, glutaraldehyde. Preferably, the crosslinking agent is applied in dilute solution and at a pH suitable to accomplish light crosslinking of the polyalkylimine and also provide aldehyde linkages at the interface between the biomolecule and the spacer.

Abstract: A non-aqueous electrochemical cell comprising an active metal anode, an organic electrolyte and a cathode comprising a minor amount of V.sub.6 O.sub.13. The resulting cell has been found to be resistant to internal gas generation. The inclusion of V.sub.6 O.sub.13 is particularly useful in lithium/manganese dioxide cells.

Abstract: A lithium battery having a weldable feedthrough which is compatible with liquid electrolytes containing organic solvents and lithium salts under long term use conditions. The feedthrough comprises a pin of niobium or tantalum and ductile alloys thereof and a low silica insulating glass positioned around a portion of the pin in sealing engagement with the pin. The feedthrough is assembled into an aperture of the battery case where it provides an electrically conductive pathway from the anode or cathode to the exterior of the case and provides a hermetic seal.

Abstract: A model of arterial restenosis in domestic pigs using deep injury to the coronary arterial media resulting in extensive proliferative response. Metal wire coils are delivered percutaneously to the coronary arteries of pigs with an oversized, high pressure (14 atm) balloon and left in place for 5-6 weeks. During placement, the balloon expands the coils and delivers them securely within the arterial lumen causing fracture of the internal elastic lamina by the coil. An extensive proliferative response occurs and is associated with a lumenal area narrowing of at least 50% Immunohistochemical studies confirms the prominence of smooth muscle cells in the tissue. The histopathologic features of the proliferative response are identical to those observed in cases of restenosis post-angioplasty.This model closely mimics the proliferative portion of human restenosis both grossly and microscopically.

Abstract: A method of and apparatus for controlling one or more parameters of an electrical stimulation generator in response to measured results of the stimulation. In the preferred mode, this technique is employed in a system for the treatment of obstructive sleep apnea. Sensors are used to determine the effectiveness of the stimulation. Amplitude and pulse width are modified in response to the measurements from the sensors.

Abstract: A method for making a seal between a sealing glass and titanium by forming a nitride layer on the titanium and then sealing the glass to the nitrided titanium. The formation of the nitride layer can be accomplished by the steps of placing the titanium in a substantially oxygen-free atmosphere comprising a major amount of an inert gas and a minor amount of nitrogen and heating the titanium in that atmosphere to a temperature of at least 300.degree. C. The method allows for the formation of the nitride layer and the glass seal in a single operation. The method works well in the manufacture of feedthroughs with conventional processing equipment.

Abstract: A vascular graft having a pleated circumference accommodates blood pressure changes with minimal change in internal surface area. A highly compliant graft may be made from a wide variety of polymers including non-elastomeric materials.

Abstract: An electrode for establishing electrical contact with nerve tissue. The electrode is chronically implantable. The outer substrate of the electrode is a semi-rigid, body compatible, insulating material such as a chronically implantable polymer. The outer substrate is molded as a single structure having a central spine along the longitudinal axis of the electrode. A plurality of fingers extend orthogonally from the central spine, and are bent circularly about a radius of curvature approximating that of the nerve to be contacted. Each of the plurality of fingers is of sufficient length to extend approximately one-half of the distance around the outer circumference of the nerve tissue. The plurality of fingers extend from the central spine in one of two opposite directions causing the electrode structure to encompass a hollow cylinder having an inside diameter the same as the nerve.

Abstract: A radially expandable stent for implantation within a body lumen having a generally cylindrical body with open proximal and distal ends, the cylindrical body comprising a plurality of metal elements joined to allow flexing of the cylindrical body along the longitudinal axis of the body whereby the stent can conform to a curved body lumen and a polymeric film extending between the metal elements of the stent. The stent provides a biocompatible polymeric surface to contact and support a body lumen and also a flexible structure to allow the stent to conform closely to bends in a body lumen. The stent is especially useful for repairing an injury to blood vessels caused during angioplasty procedures.

Abstract: A technique for reducing fatigue associated with artificially stimulated contractions of muscle tissue. The stimulation of the muscle tissue is associated with treatment of a particular medical condition, such as obstructive sleep apnea. For this application, the muscles of the upper airway are stimulated to relieve or prevent obstruction to normal respiratory activity during sleep.Fatigue is reduced by stimulating the subject muscles from multiple rather than a single electrode. This ensures that successive depolarizations are not produced from the same focus, and that different motor units are successively depolarized.Each electrode is placed at the muscle nerve interface to recruit the assistance of the nerve tissue in conducting the stimulation signals throughout the muscle. The conductors coupling the individual electrodes share a common cable structure to produce ease in the implant procedure. The electronics of the stimulation pulse generator is conveniently demultiplexed to eliminate excess hardware.

Abstract: A plasma treatment apparatus for treating elongated clear polymeric tubing, by moving the tubing through a plasma generation chamber and maintaining tension on the tubing below that at which clarity of the tubing is reduced.

Abstract: Biocompatible heparin-like material and surfaces thereof are made by co-polymerization of acrylic acid (AA) and 2-acrylamido-2-methyl propane sulfonic acid (AMPS) and attaching the copolymer to a suitable substrate or blending the copolymer into a suitable substrate. The material produced also possesses surface slip-properties and some decreased bacterial and platelet adherence.

Abstract: An apparatus designed to test blood, blood contacting biomaterials and devices such as materials and surface-modified materials; vascular grafts, stents, heart valves, catheters, leads, etc., for blood and material responses in vitro under physiological blood flow conditions. The apparatus consists of a stepper-motor driven circular disc(s), upon which a test vehicle, containing either the test materials, coating or device, is mounted. The test vehicle itself consists of a circular, closed-loop of polymer tubing containing a check valve.

Abstract: A method for making a conductive coated product comprising the steps of abrading a conductive metal substrate, applying to the conductive metal substrate a layer of a curable composition which includes 2-acrylamido-2-methylpropanesulfonic acid, water and/or alcohol, and a curing agent and curing the composition on the substrate.

Abstract: A vascular graft with improved endothelial cell adhesion can be achieved on a fluoropolymer surface of a vascular graft by treating the fluoropolymer with a plasma in the presence of a non-polymerizing gas capable of providing the fluoropolymer with anionic groups and binding a protein to the treated fluoropolymer. In a preferred embodiment, the fluoropolymer surface is a plasma deposited fluoropolymer. Also in a preferred embodiment, autologous endothelial cells are seeded onto the vascular graft prior to implantation of the vascular graft in the human body.

Abstract: A method for modifying the surface characteristics of a polymeric material by irradiating a surface of the polymeric material in the presence of an oxygen and then grafting acrylamide to the irradiated surface by contacting the irradiated surface with an aqueous solution including acrylamide monomer and ceric ion. Grafted polymer surfaces with dense surface coverage are produced without using a deaerated monomer solution. Biofunctional molecules can be ionically or covalently bonded to the grafted surface.

Abstract: Improved high rate cathode material and method of making same by chemical addition reaction.

Abstract: An implantable system for the treatment of obstructive sleep apnea by electrical stimulation of the musculature of the upper airway. The system employs one or more sensors to determine the onset of an apnea event. Upon sensing of the onset of an apnea event, the stimulation generator provides a signal for stimulating the muscles of the upper airway at a varying intensity wherein the intensity is gradually increased during the course of the stimulation. The signal is coupled to the muscles to be stimulated by an electrode connected to the stimulation generator by an insulated lead.