Abstract: A filter capacitor comprising a pre-sintered substrate supporting alternating active and ground electrode layers segregated by a dielectric layer is described. The substrate is of a ceramic material that maintains its shape and structure dimensions even after undergoing numerous sintering steps. Consequently, relatively thin active and ground electrode layers along with the intermediate dielectric layer can be laid down or deposited by a screen-printing technique. Using a relatively thin over-glaze in comparison to a thick upper dielectric layer finishes the capacitor. Consequently, a significant amount of space is saved in comparison to a comparably rated capacitor or, a capacitor of a higher rating can be provided in the same size as a conventional prior art capacitor. The pre-sintered ceramic substrate is used instead of conventional tape cast technology for the base dielectric.

Abstract: Terminal pins comprising an outer coating of palladium coating a core material other than of palladium for incorporated into feedthrough filter capacitor assemblies are described. The feedthrough filter capacitor assemblies are particularly useful for incorporation into implantable medical devices such as cardiac pacemakers, cardioverter defibrillators, and the like, to decouple and shield internal electronic components of the medical device from undesirable electromagnetic interference (EMI) signals.

Abstract: Minimally invasive introducers and methods that can be used for rotationally securing devices within the human body. Introducers can include a distal element for releasably engaging a lead head controllable from a proximal control located outside of the body. An inner stem can extend between a proximal portion and a distal portion, and be pivotally and rotatably coupled to the distal lead engagement mechanism. An outer tube can be rotatably disposed over the inner stem and be flexibly coupled over the pivot to rotationally drive the distal element. A helical epicardial-myocardial lead electrode can be secured and oriented straight ahead and introduced through a port or small incision with the introducer in a straight configuration. The introducer can then be bent and rotated to screw the helical electrode into the heart.

Abstract: A new cathode design has a first cathode active material of a relatively low energy density but of a relatively high rate capability contacted to the outer sides of first and second cathode current collectors and a second cathode active material having a relatively high energy density but of a relatively low rate capability in contact with the inner sides of the current collectors. The first and second current collectors have a thickness in the range of from about 0.001 inches to about 0.002 inches. A conventional Li/SVO cell powering an implantable medical device has the cathode with a current collector of about 0.003 inches. Even though the present current collectors are about one-half as thick as that of a conventional cell, their combined thickness means that the cell has no reduction in current carrying capacity.

Abstract: An insulator structure forming a physical barrier encapsulating the entire electrode assembly including all the positive portions and segregating them from the negative leads and the casing is described. By completely encapsulating the electrode assembly including the cathode lead portions from the anode leads and the casing, no opposite polarity structures that can potentially serve as a surface for lithium bridging are left exposed to electrolyte.

Abstract: A capacitor a casing of first and second casing members, a feedthrough electrically insulated from the casing and extending there from, first and second anodes electrically connected to each other within the casing, a cathode, and an electrolyte is described. The first anode is electrically connected in parallel to the second anode by a first anode wire having opposite ends contacting the respective first and second anodes. A feedthrough wire extending outside the casing and electrically isolated there from is electrically connected to the first anode wire intermediate the first and second anodes. The cathode is disposed between the first and second anodes.

Abstract: Nickel-based alloys are provided for use as a positive electrode current collector in a solid cathode, nonaqueous liquid electrolyte, alkali metal anode active electrochemical cell. The nickel-based alloys are characterized by chemical compatibility with aggressive cell environments, high corrosion resistance and resistance to fluorination and passivation at elevated temperatures, thus improving the longevity and performance of the electrochemical cell. The cell can be of either a primary or a secondary configuration.

Abstract: The prevention of lithium clusters from bridging between the negative and positive portions of a cell during discharge is described. This is done by limiting the amount of electrolyte in the cell, thereby eliminating excess electrolyte pooling above the cell stack. It is in this excess electrolyte that a relatively higher Li+ ion concentration can occur, creating an anodically polarized region resulting in the reduction of lithium ions on the negative and positive surfaces as the concentration gradient is relaxed. Typically, a lithium ion concentration gradient sufficient to cause lithium cluster formation is induced by the high rate, intermittent discharge of a lithium/silver vanadium oxide (Li/SVO) cell.

Abstract: A capacitor is described. the capacitor includes a casing; a cathode of an active material of at least an oxide of a first metal provided on a substrate, wherein the active material is characterized as being of a substantially homogeneous coating formed by sputtering a target of the first metal in a vacuum chamber; an anode spaced from the cathode coating; and an electrolyte in contact with the cathode coating and the anode. The casing contains the anode, the cathode and the electrolyte. A method and apparatus for providing the sputtered coating is also disclosed.

Abstract: High reliability electrical connections between a helical strand and flat electrodes, such as strip electrodes found in implantable neurostimulator systems, are described. The connection consists of a crimp joint in which an inside diameter mandrel is used to provided the coil with sufficient radial rigidity to ensure structural integrity of the crimp. The mandrel is made of a relatively soft biocompatible material that deforms rather than damages the fine wires of the helical strand during crimping. The crimp is accomplished by radial deformation of an annular or semi-annular crimping member that receives the helical strand/mandrel assembly.

Abstract: It is known that reforming implantable defibrillator capacitors at least partially restores and preserves their charging efficiency. An industry-recognized standard is to reform implantable capacitors by pulse discharging the connected electrochemical cell about once every three months throughout the useful life of the medical device. A Li/SVO cell typically powers such devices. The present invention relates to methodologies for significantly minimizing, if not entirely eliminating, the occurrence of voltage delay and irreversible Rdc growth in the about 35 % to 70 % DOD region by subjecting Li/SVO cells to novel discharge regimes. At the same time, the connected capacitors in the cardiac defibrillator are reformed to maintain them at their rated breakdown voltages.

Abstract: A titanium substrate having a thickened outer oxidation layer provided thereon by a treatment process performed either in an air atmosphere at elevated temperatures or through electrolytic oxidation (anodization), is discribed. The thusly conditioned titanium substrate serving as a cathode current collector for an electrode incorporated into an electrochemical cell exhibits improved electrical performance in comparison to the prior art techniques, i.e., electrically conducted carbon coated titanium screen and use of highly corrosion resistant materials, upon subsequent elevated temperature exposure.

Abstract: An oxygen plasma process for treating a dielectric oxide layer, particularly an anodic oxide, subsequent to its incorporation into an electrolytic capacitor is described. The present treatment reduces DC leakage and improves shelf life stability of the resulting capacitor in comparison to anodic oxides treated in a conventional manner. This is important for critical applications such as implantable cardioverter defibrillators where capacitor charging time and charge/discharge energy efficiency are critical.

Abstract: A primary lithium electrochemical cell housed in a casing having a curved side wall intermediate opposed generally planar face walls is described. The cell comprises an anode and a cathode that each has a plurality of face portions joined together by connecting portions. The opposite polarity face portions and connecting portions are aligned with each other and then the electrodes are wound to provide an electrode assembly that fits in the casing. Regardless whether the cell is balanced as either an anode-limited or cathode-limited configuration, however, it is desirable to have the active material of one electrode face portion directly facing the electrode material of the counter electrode face portion. This means that the dimensional extent of the facing electrodes should be as close to each other in areas as possible to match the desired anode- or cathode-limited balance. The same is true for the connecting portions. The cell is of a high energy density for an implantable biomedical device.

Abstract: An electrical energy storage device such as a wet tantalum electrolytic capacitor or an electrochemical cell such as a lithium/silver vanadium oxide cell is described. The enclosure comprises a drawn casing portion having a planar face wall supporting a surrounding sidewall and is shaped to nest the anode, cathode and intermediate separator components. A mating cover is a stamped planar piece of similar material having a periphery edge welded to the edge of the casing portion surrounding sidewall. In order to prevent heat generated during the welding process from damaging the separator, the anode portion adjacent to the weld site is contoured. This provides sufficient space between the weld and the separator supported on the anode at the contour so that what heat is transmitted to the separator by convection and conduction mechanism will not damage the separator.

Abstract: A means for determining long-term discharge performance, particularly in a lithium/silver vanadium oxide cell, by analyzing and characterizing the initial pulse voltage waveform, is described. The relationship between the initial P1 (Pmin) voltage drop and the extent of that initial voltage drop with Plast (the final voltage under load) is a reliable indication of long-term discharge performance.

Abstract: The present invention is directed to calendaring an electrode active admixture, such as of a transition metal oxide, and particularly silver vanadium oxide, into an electrode structure. To obtain electrode structures of a desired low basis weight requires calendaring a paste of the active material into a first sheet tape, which is subsequently subjected to secondary and ternary calendering steps. Secondary calendaring is performed in a direction reverse or orthogonal to that used to form the initial sheet tape. The final calendaring step is performed in a third direction aligned 180° with respect to the first direction, but with the second structure rotated bottom over top with respect to the orientation that formed the first and second structures. The ternary calendaring step provides for fibrillation of the fluoro-polymeric binder in a direction reverse to the initial direction to form the product low basis weight electrode active structure.

Abstract: Deposition of a metal-containing reagent solution or suspension onto a conductive substrate by various pad-printing techniques is described. The result in a pseudocapacitive oxide coating, nitride coating, carbon nitride coating, or carbide coating having an acceptable surface area for incorporation into an electrolytic capacitor, such as one have a tantalum anode.

Abstract: The present invention broadly comprises a method and apparatus for testing electrochemical cells which is faster and more cost-effective than current testing methods. Accordingly, the invention provides a method for testing electrochemical cells, particularly batteries for medical applications, such as for implantable devices for pacemakers, defibrillators, etc., comprising the steps of: surrounding at least one electrochemical cell with a vacuum with a pressure range of 0 to 0.001 Torr and measuring energy emitted from the electrochemical cell.

Abstract: An improved cathode material for nonaqueous electrolyte lithium electrochemical cell is described. The preferred active material is ?-phase silver vanadium oxide (Ag2V4O11) coated with a protective layer of a metal oxide, preferably ?-phase SVO (Ag1.2V3O1.8). The SVO core provides high capacity and rate capability while the protective coating reduces reactivity of the active particles with electrolyte to improve the long-term stability of the cathode.