Abstract: An electrode configuration for an automatic implantable cardioverter/defibrillator system and method for its use are disclosed. The electrode configuration includes a first catheter transvenously positioned with a first electrode near the distal end of the catheter positioned in the right ventricle of a patient's heart. A second catheter carries second and third electrodes with the second electrode positioned in the superior vena cava region and the third electrode positioned in the left innominate vein. The second and third electrodes of the second catheter are connected together. A fourth electrode at the tip of the first catheter functions as a sensing/pacing electrode. A fifth electrode in the form of a subcutaneous patch is also electrically coupled to the second and third electrodes. The electrode arrangement can be positioned without the need for a thoracotomy.

Abstract: An electrochemical capacitor is prepared by assembling a stacked assembly of at least two bipolar electrodes, where each of the bipolar electrodes includes a metal foil electrode substrate having a porous, electronically conductive substrate coating, preferably porous platinum, on each surface. The stacked assembly further has a porous separator layer between each of the electrodes, made of a material that is electronically non-conductive. An ionic conductor electrolyte, preferably a polyoxometalate, that wets both the substrate coating and the separator layer at temperatures above the melting point of the solid ionic conductor electrolyte is provided, the ionic conductor electrolyte having a melting point above about 30.degree. C. The ionic conductor electrolyte is introduced into the stacked assembly, as by external infiltration with an optional applied pressure to assist the infiltration.

Abstract: A programmable implantable medical device utilizable for delivering a configurable defibrillation waveform to a heart. The device includes defibrillation electrode means adapted to be connected to the heart for delivering a multiphasic defibrillation waveform thereto. A programmable waveform generator connected to the heart generates the multiphasic waveform such that at least one phase of the defibrillation waveform has programmed constant tilt.

Abstract: An implantable cardiac defibrillation electrode is provided, in which there is an electrically conductive wire mesh formed of crossed spirally wound cables. Each of the spirally wound cables comprises a plurality of stranded wire elements, with a central wire element and a plurality of outer wire elements wound adjacent the central wire element. In one embodiment, the crossed cables are formed in a twill weave pattern, alternating over and under at least two individual cables.

Abstract: A system is provided for fastening an implantable medical device, for example a defibrillator lead, to the heart. A lead electrode is placed in a desired position against the pericardium, pericardial tissue is grasped with a fastening tool, and the pericardial tissue is drawn away from epicardium and toward the fastening tool. A fastening member is applied to the pericardial tissue and to the lead electrode to secure the lead in the desired position. The application tool comprises a first pair of jaws for grasping membranous tissue and drawing the tissue away from other tissues and toward the tool. A second pair of jaws is provided for holding fastener members and delivering the fastener members to the membranous tissue.

Abstract: An implantable defibrillator lead comprises a flexible, conductive lead member having proximal and distal end portions. The distal end portion defines a plurality of separate, curvilinear electrodes which naturally extend laterally outwardly in a curved arrangement from the remainder of the lead. However, by desired means, the curvilinear electrodes may be temporarily extended out straight, substantially parallel to the axis of the remainder of said lead member, to facilitate implantation of the lead. This may be preferably accomplished by a flexible sheath that encloses the lead member in longitudinally slidable relation.

Abstract: A lead or other member may be implanted into the body, and typically at the heart, by a method which comprises and following: inserting one of a pair of pivotally attached jaws of an attachment tool through a hole in a body membrane, particularly the parietal pericardium surrounding the pericardial cavity. The other of the pivotally related jaws is placed outside of the body membrane in a position of registry with the first of the jaws. The jaws carry an attachment member which is to be attached for securance to the body membrane. The jaws are brought together in pressing relation with the membrane and attachment member positioned between the jaws, to cause attachment of the attachment member to the membrane. The lead may be pre-attached, or subsequently attached, to the attachment member after the above process steps.

Abstract: A medical device is provided for monitoring waveform complexes of intracardiac electrograms. The intracardiac electrogram is identified by determining, with respect to a waveform peak of the intracardiac electrogram, its amplitude, width and polarity. The identification criteria are averaged and stored to provide a standard complex. Subsequent complexes are compared to the stored standard complex. Such comparison includes comparing peaks of subsequent complexes with the peaks of a stored standard complex, aligning subsequent complexes with a stored standard complex, and providing a score associated with the comparisons and alignment.

Abstract: A method for making an electrochemical capacitor is disclosed. A plurality of bipolar electrodes having porous conductive oxide coatings on opposite sides of a thin metal foil are first produced in a fixture assembly using sol-gel processing techniques. A dielectric oxide coating is then applied to one or both conductive coatings using the sol-gel process. A stack of a plurality of the bipolar electrodes with adjacent electrodes separated by a predetermined amount of a solid electrolyte is assembled. The stacked assembly is heated to a temperature above the electrolyte melting point allowing the molten electrolyte to infiltrate the porous coatings. Pressure is applied to the stacked assembly sufficient to produce intimate contact between adjacent surfaces of the bipolar electrodes while expelling excess liquid from between the electrode surfaces. The stacked assembly is cooled in a controlled fashion to produce a laminate structure.

Abstract: An antitachycardia device, either implanted or external, which delivers a fixed pulse width truncated exponential waveform defibrillation shock and automatically adjusts the pulse duration based upon the impedance measured or calculated following a delivered shock. The apparatus operates by measuring or calculating the high voltage system impedance, selecting a pulse width for that impedance value and using a pulse width derived from the selected pulse width for the next defibrillation shock.

Abstract: A method of manufacturing a medical electronic lead portion having an elastomeric mass and typically having a conductive metal member embedded in the elastomeric mass. The method includes the step of eroding elastomer of the mass from around the conductive metal member to form a predetermined shape by exposing the lead portion to a jet of gas containing entrained, particulate abrasive. Preferably, the particulate abrasive is softer than the conductive metal member to avoid scratching thereof. For example, soluble particulate abrasive such as sodium bicarbonate can be used.

Abstract: A boot manufactured from a bio-compatible material is used to smooth the external shape of an implantable medical device and to seal the device against fluid intrusion.

Abstract: A method is provided for calculating the unambiguous ranges of a radar target in a radar system employing multiple PRFs. The radar system provides digitized data items indicative of return signals in each of a plurality of range intervals for each PRF. A base PRF is selected and a range interval containing a target return signal is selected therefrom. This range interval is correlated with particular range intervals of the remining PRFs to find specific target return signals therefrom which satisfy a first predetermined relationship. This relationship generally provides that a target is identified if a preselected number of correlated range intervals of all PRFs have target return signals therein. If this relationship is satisfied, the target range is calculated from a range equation.

Abstract: A dielectrically loaded waveguide switch is disclosed which provides high power handling capability, small size and low weight. The invention includes first and second dielectrically loaded waveguides selectively connected by a switch. In a specific embodiment of the invention, the switch includes a third dielectrically loaded waveguide mounted for communication with said first and second waveguides upon switch actuation.

Abstract: A system is coupled to a pointing mirror (12) for stabilizing it and its line-of-sight (13) from three-dimensional rotational disturbances (.omega..sub.i, .omega..sub.j, .omega..sub.k) exerted thereon. First and second two-degree-of-freedom dynamically tuned gyroscopes (26, 28) are secured to the mirror and placed respectively on its elevation and azimuth axes (22, 24). The first gyroscope (26) is coupled to electronic apparatus (30) to provide inertial rates (.omega..sub.4 *, .omega..sub.2 *) of the mirror respectively about an axis (13) angled from a line (17) normal thereto and about the elevation axis. The second gyroscope (28) is coupled to the electronic apparatus to provide inertial rates (.omega..sub.2, .omega..sub.3) of the mirror respectively about its pitch and yaw axes. Inertial rates (.omega..sub.e, .omega..sub.d) of angular motion of the mirror respectively about its line-of-sight pitch and yaw axes (e, d) are calculated from the inertial rate (.omega..sub.4 *, .omega..sub.2 *, .omega..sub.2, .

Abstract: A digital switching voltage regulator 10 for providing regulation about a single voltage despite the current supplied thereby is disclosed herein. The digital switching voltage regulator 10 of the present invention includes a first voltage regulation module 12 for regulating, within a first voltage regulation window RW1 defined by first upper and lower threshold voltages, the voltage across a load 21 operatively coupled to the regulator 10. The regulator 10 of the present invention further includes a second voltage regulation module 14 for regulating the voltage across the load 21 within a second voltage regulation window RW2 defined by second upper and lower threshold voltages. The second voltage regulation window 14 is included within the first voltage regulation window 12 and, in a preferred embodiment, the first and second regulation windows RW1 and RW2 are centered about a common voltage.

Abstract: A satellite communications system employs separate subsystems for broadcast and point-to-point two-way communications using the same assigned frequency band and employs an antenna system which uses a common reflector (12). The point-to-point subsystem achieves increased communication capacity through the reuse of the assigned frequency band over multiple, contiguous zones (32, 34, 36, 38) covering the area of the earth to be serviced. Small aperture terminals in the zones are serviced by a plurality of high-gain downlink fan beams (29) steered in the east-west direction by frequency address. A special beam-forming network (98) provides in conjunction with an array antenna (20) the multiple zone frequency address function. The satellite (10) employs a filter interconnection matrix (90) for connecting earth terminals in different zones to permit multiple reuse of the entire band of assigned frequencies.

Abstract: A digital sequencing apparatus produces a series of contiguous enable gates or strobe signals. The apparatus includes an even number, and at least two alternating stages of cross-coupling NOR gates alternating with cross-coupled NAND gates where one of the cross-coupled NOR gates in each stage has a merged AND gate at one input and one of the NAND gates in each stage has a cross-coupled OR gate at one input. This apparatus produces contiguous enable gates in response to complementary clock inputs to each of the stages upon the input of a start signal to the first two stages of the apparatus.

Abstract: A method of bonding molybdenum and zinc sulfide devices (10, 12) together comprising the steps of lapping the surface of the nickel layers to about a 20,000 Angstrom smoothness, placing nickel layers (16, 16') of about 700 Angstroms respectively on the devices, plating layers of gold (18, 18') of about 4 microns thickness respectively on the nickel layers, respectively immersing the gold-plated layers in a bath (20) of mercury, inverting one (10) of the devices above the other (12), bringing the devices together to effect contact between the mercury films (22, 22'), pressing the devices together within a pressure range of 2 kilograms per square inch to 20 kilograms per square inch for a minimum of 16 hours at room temperature, and sealing the periphery of the gold-mercury seal contact with a nickel seal (26).

Abstract: An optical sensing system is described which generally comprises an infrared sensor, and a curved diffraction-limited window disposed in front of the sensor such that the optical axis of the sensor is parallel to and displaced from the symmetry axis of the window. The window has an inner radius of curvature which is non-concentric with the outer radius of curvature in order to remove the optical power of the window. Additionally, the window is provided with an aspheric profile outer surface, in order to correct for spherical aberrations in the window. The window is made out of germanium and is particularly useful for a sensor which has an 8-12 micron infrared radiation detection band width.