Abstract: A stent for implantation in a body vessel in which a cylindrical stent body coiled from a generally continuous wire with a zig-zag structure is provide with attachment of the wire ends to an adjacent coil.

Abstract: Two mechanisms work together to adjust two variables independently so that the gain of an input amplifier used to find physiologic signals in an implantable medical device can be automatically adjusted to enhance the signal to noise ratio of the electrical input to said amplifier. The first determines whether there has been too long a time between senses found in the body's electrical input to the amplifier and if true, and no other conditions override that consideration, it adjusts the value of a long term average parameter which is used as a referent parameter to adjust the actual parameter that is used as the referent for making either a threshold level adjustment or gain change, depending on the structure of the particular design's circuitry and/or software. One set of adjustments to the gain referent parameter depends on the relative size of the long term average parameter and the gain referent parameter.

Abstract: At least a portion of a catheter which is intended to be in contact with bodily tissue for more than a nominal period of time is loaded with an anti-inflammatory agent such as dexamethasone sodium phosphate. The direct loading or compounding of the catheter with the agent resists inflammation and encapsulation of the catheter as a result of the tissue's natural foreign-body response. The anti-inflammatory agent can be provided as a coating or bonded on the outside of the catheter or can be integrally compounded into the body of the catheter.

Abstract: Techniques using one or more drugs, electrical stimulation or both to treat addictions by means of an implantable signal generator and electrode and an implantable pump and catheter. A catheter is surgically implanted in selected sites in the brain to infuse the drugs, and one or more electrodes are surgically implanted in the brain at selected sites to provide electrical stimulation.

Abstract: A medical device comprising a biomaterial formed from a polymer comprising urethane groups, urea groups, or combinations thereof, and sacrificial moieties that preferentially oxidize relative to other moieties in the polymer.

Abstract: A system for chronically measuring a physiologic parameter by an implantable device which has several forms is described. At its core a fixture for holding on to a blood vessel and forcing a sensor against a surface of the vessel is taught. Numerous adaptations and uses with various sensors are described.

Abstract: An implantable medical device determines activity levels over a set of time periods, preferably on the order of seconds, minutes and hours and a display is enabled for days or weeks at recorded activity levels over a range of dates. This enables physician review of patient functional status. Additional physiologic data can be recorded along with the activity data, and this too may be reported out from the implanted device to a medical communications system for alarm purposes, titrating drugs or other monitoring tasks.

Abstract: The invention is a peristaltic pump having a particularly simple construction and a low axial bulk.The pump (1) includes a rotor (20) having rollers (21,22,23) which roll against a tube (14) containing the liquid to be pumped. The compression of the tube presses the rollers against the circular peripheral surface (35) of a central vibrating stator (32) in the form of a disc or ring, which guides the rollers and causes them to turn. The stator (32) is set in vibration by piezoelectric means and vibrates by extension in its radial plane following a progressive wave. The chassis (24) of the rotor is devoid of a central drive shaft.Such a peristaltic pump is notably useful in the medical domain, in machines to be worn by a patient or implanted in the body of a human being or animal.

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: An implantable medical device such as a defibrillator is described. The device includes an hermetically sealed housing containing a flat electrolytic capacitor and an energy source such as a battery. The battery is connected to the capacitor and provides charge thereto. The capacitor stores the charge at a relatively high voltage. The charge stored in the capacitor is discharged through a defibrillation lead to a site on or in the heart when fibrillation of the heart is detected by the implantable medical device. Methods of making and using the implantable medical device, the capacitor, and their various components are disclosed.

Abstract: A lead which is provided with a lead body and a connector assembly which are flexible and resistant to fatigue caused by flexing of the lead relative to an associated implantable medical device to which the lead is coupled. The lead is provided with an elongated lead body with a connector assembly located at its proximal end and carrying at least two elongated conductors extending along the lead body to the connector assembly, arranges such that distal to a first point along the lead body the lead body is provided with at least two separate longitudinal lumens, each carrying at least one of the two conductors and proximal to the first point, the lead is provided with a tubular member, arranged such that the two conductors extend proximally from the first point wrapped helically around the tubular member. In a preferred embodiment, the lead carries at least three elongated conductors, and at least one of the conductors is wrapped helically around the tubular at a pitch greater than the diameter the conductors.

Abstract: An electrosurgery medical device is enhanced with unique solution-assistance, and includes, in combination, co-operating device jaws including jaw portions for manipulating tissue, and a plurality of solution infusion openings defined and spaced along each of the jaw portions, for receiving electrolytic solution and infising the solution onto and into tissue to be manipulated, along said jaw portions. As preferred, the device further comprises at least one, and most preferably, many, longitudinal groove(s) along at least one and most preferably, both, of the jaw portions, with the solution infusion openings located in the groove or grooves. The solution is energized with RF energy and contributes to the functions and beneficial effects of the instrument. The solution exits the openings in the grooves at sufficient flow rates to separate substantially all the operative surfaces of the device from tissue, thereby substantially completely preventing adherence between the operative surfaces and tissue.

Abstract: This present invention provides a method for forming C-SVO without the need for flowing O.sub.2 during its synthesis. A method of forming silver vanadium oxide in accordance with the present invention includes combining AgO with a vanadium-containing compound to form a mixture; and exposing the mixture to a sufficient temperature for a time effective to form silver vanadium oxide. A method of forming the silver vanadium oxide for use as a cathode material is disclosed.

Abstract: An implantable medical device (IMD) includes a distributed core, step-up transformer that is arranged within a hermetically sealed housing in space that would otherwise not be occupied and in a way that minimizes the size and weight of the IMD. The IMD preferably comprises an implantable cardioverter-defibrillator (ICD) of the type having a battery power source, a capacitor bank for storing a charge from the battery, and electronic circuitry coupled to the battery power supply and the capacitor bank for charging the capacitor bank through a step-up transformer and for discharging the capacitor bank into or around a patient's heart. The step up transformer comprises a plurality of distributed core step-up transformer modules which are miniaturized sufficiently to fit within small spaces of the housing cavity. The plurality of distributed core, step-up transformer modules are amenable to being arranged to fit into spaces within the cavity of the IMD housing that are not otherwise occupied.

Abstract: An intraparenchymal infusion catheter system for delivering drugs or other agents to selected sites in an organism, such as a human, includes a pump that may be implanted or disposed outside the organism. A catheter is coupled to the pump. The catheter comprises a flexible biocompatible tubular portion terminating in a free distal end. The distal end of the catheter bears a rounded tip, a portion of which is slidably disposed within the lumen of the tubular portion. The tip is porous for discharging an agent or drug to a selected site. The tip has a microporosity of less than or equal to 0.22 microns. The tubular portion is composed from a material that will expand from its nominal size when exposed to a stimulus such as heat or a solvent and return to its nominal size when the stimulus is withdrawn. By expanding the tubular portion, a physician can select the amount of the tip that is exposed to the organism, thereby customizing the catheter to the structural size of the selected site within the body.

Abstract: An alternative mechanism in an implantable device for meeting the physician's need for a stored electrogram and/or other stored physiologic signal associated with a detected arrhythmic or other physiological event without the undesirable current drain associated with continuous operation of a sense amplifier and a looping memory. The device regularly but intermittently activates a sense amplifier or other sensor and associated memory circuitry, independent of detection of arrhythmias. The device may temporarily store only a single record, replacing it with new records as they are stored, or may store multiple records, replacing the oldest stored record with the newest stored record. On detection of an arrhythmia or other defined physiological event, the device may simply transfer the one or more temporarily stored electrogram strips to permanent storage, for later use by the physician in diagnosing the condition of the patient prior to detection of the event.

Abstract: A medical device comprising a catheter and a balloon-expandable stent having a small initial diameter, flexibility along its longitudinal axis prior to expansion, a large expanded diameter, and rigidity after expansion. Local strain on the stent material is minimized, as and after the balloon is inflated. More particularly, the sent has rotation joints having minimal strain during stent expansion. The stent is substantially the same length before and after expansion and, being flexible longitudinally when constrained, is easy to deliver.

Abstract: An implantable anti-tachyarrhythmia device which delivers atrial cardioversion or defibrillation pulses heart in response to detection of atrial tachyarrhythmias. The pulses are synchronized to atrial and ventricular events in such a fashion as to assure they occur outside of the vulnerable periods associated with both chambers. The device is provided with a pulse synchronizer which defines a first synchronization interval initiated following a sensed atrial event and a second synchronization interval initiated responsive to a sensed ventricular event and a pulse triggerer which triggers delivery of a cardioversion or defibrillation pulse responsive to the first and second synchronization intervals simultaneously being underway. In particular, the pulse triggerer may be responsive to initiation of the first synchronization interval during the second synchronization interval.

Abstract: Power consumption in medical devices is reduced through the application of different supply voltages to analog and digital circuits, respectively. The medical device generally includes analog circuits (e.g., an atrial sense amplifier, a ventricular sense amplifier, a T-wave amplifier, bandpass filters, detection circuits, sensor amplification circuits, physiological signal amplification circuits, output circuits, a battery monitor circuit, and a power on reset circuit) and digital circuits (e.g., a processor, a controller, and a memory) with the supply voltage applied to the analog circuits being greater than that applied to the digital circuits. A source applies a first fixed supply voltage to the digital circuits of the medical device and a voltage generation circuit (e.g., a charge pump circuit) having the first fixed supply voltage applied thereto is used for generating a second fixed supply voltage to be applied to analog circuits of the medical device.

Abstract: A body implanted device including a container having an opening through which extends an electrical feedthrough. The feedthrough includes a terminal of bio-stable material. A glass insulator is positioned around the terminal. The glass insulator is chosen from a CABAL-12 type composition or variation thereof. The terminal is comprised of a material which has thermal expansion characteristics compatible with the glass seal. For glass seals having a thermal expansion in the range of 6.8 to 8.0.times.10.sup.-6 in/in/.degree. C. the terminal is comprised of a thin layer of titanium metallurgically clad over niobium or tantalum. For glass seals having a thermal expansion in the range of 8.0 to 9.0.times.10.sup.-6 in/in/.degree. C. the terminal is comprised of platinum, platinum-iridium or alloys of either, or of pure titanium.