Abstract: An electrical conductor assembly utilized, for example, in a defibrillator patch lead to interconnect a pulse generator and monitoring unit, and a wire mesh electrode pad. The electrical conductor includes a Teflon insulated drawn brazed stranded (DBS) wire cable which is wrapped in a drawn filled tube (DFT) wire multifilar coil encased in a biocompatible insulative tubing.

Abstract: An implantable cardioverter-defibrillator (ICD) provides a tiered therapy designed to automatically terminate tachyarrhythmias using the least aggressive therapy possible while reducing the "time-to-therapy." The tiered therapy first applies a first tier of therapy (e.g., antitachycardia). If unsuccessful, the tiered therapy next applies a second tier of therapy (e.g., cardioversion pulse with a pulse of moderate energy). If unsuccessful, the tiered therapy finally applies a third tier of therapy (e.g., a high energy pulse). So that more aggressive (higher energy) tiered therapies may be applied as early as possible following the failure of a less aggressive (lower energy) therapy, the ICD begins charging one or more high voltage capacitors of the ICD in parallel with the application of the less aggressive therapy, and/or in parallel with the verification interval immediately following a prior therapy attempt during which the ICD attempts to verify the successful termination of the tachyarrhythmia.

Abstract: A method of re-configuring any pre-fabricated plastic package (with or without a silicon chip and wires inside) so that an integrated circuit chip can be installed and interconnected for normal use. A pre-molded plastic package is abraded over (or molded to expose) the die attach pad and the wire bond pads. Advantageously, the encapsulating material is removed without damaging the plating material on the lead frame. A new chip is then mounted onto the chip mounting pad and new wire bonds are connected between the new chip and the lead frame. Encapsulating material, such as epoxy, is then placed over the chip and wire bonds and cured.

Abstract: An in-line, multipolar proximal connector assembly for an implantable stimulation lead is provided which incorporates at least one sensor. Advantageously, the present invention uses straight conductive rods, or wires, to electrically connect the proximal terminals to a multilumen lead body. The straight conductive rods enable the diameter of the lead assembly to remain small. Additional terminals can easily be added by simply decreasing the spacing between terminals and adding additional conductive rods. In one embodiment, insulating spacers are premolded to include protruding portions which interlock with the ring terminals. Recesses within the insulating spacers are dimensioned to self-position the ring terminals a precise distance from the pin terminal according to precise dimensions defined by the VS-1 (or other) standards. In another embodiment, the terminals are injection molded.

Abstract: A ribbon conductor set and related method of production and installation are provided for electrically interconnecting components in an implantable medical device, such as a heart pacemaker unit or the like. The ribbon conductor set is formed by die cutting and/or stamping a thin plate of conductive material to define a plurality of conductor ribbons supported from a frame. The ribbon set and supporting frame are shaped for seated placement into a fixture to orient the conductor ribbons in predetermined array to extend between electrical components on the fixture, such as between connector blocks and feedthrough terminals of a heart pacemaker unit. The fixture thus supports the conductor ribbons for facilitated connection to the electrical components, such as by welding, after which the resultant subassembly may be further processed as by encapsulation within a cast epoxy head or the like.

Abstract: A physiological sensor forms an integral part of an implantable stimulation/sensing lead used with a medical device, such as a pacemaker. The stimulation/sensing lead includes a tip electrode to which a distal end of a first conductor is connected. The sensor is inserted in series with respective portions of a second conductor. A distal end of the second conductor/sensor is connected to the tip electrode. Operation of the stimulation/sensing lead occurs unipolarly through the first conductor only, with a signal return path being provided through the tip electrode and conductive body fluids. The sensor does not form part of the electrical circuit to the tip electrode, and there are no electrical connections or breaks in the insulation along the entire length of the first conductor.

Abstract: The present invention includes a body implantable lead having a multi-polar proximal connector, at least a first conductor coupled to at least one stimulating electrode, a sensor for sensing at least one physiologic parameter of the body, and a second and a third conductor coupled to the sensor. The sensor is hermetically sealed in a D-shaped housing. Sensor components are mounted onto a microelectronic substrate which is advantageously placed on an inner flat portion of the D-shaped housing. End caps having glass frit sealing rings are used to seal the ends of the shell. A hermetic seal is easily achieved by heating the glass frit such that the glass frit reflows between the end caps and the shell. Advantageously, the sensor terminals are sized to fit snugly within a narrow bore of the end cap which is then welded closed. The D-shaped sensor is placed on a carrier having at least two lumens.

Abstract: A ribbon conductor set and related method of production and installation are provided for electrically interconnecting components in an implantable medical device, such as a heart pacemaker unit or the like. The ribbon conductor set is formed by die cutting and/or stamping a thin plate of conductive material to define a plurality of conductor ribbons supported from a frame. The ribbon set and supporting frame are shaped for seated placement into a fixture to orient the conductor ribbons in predetermined array to extend between electrical components on the fixture, such as between connector blocks and feedthrough terminals of a heart pacemaker unit. The fixture thus supports the conductor ribbons for facilitated connection to the electrical components, such as by welding, after which the resultant subassembly may be further processed as by encapsulation within a cast epoxy head or the like.

Abstract: An implant tool for use with an endocardial or other implantable lead having an extendable/retractable positive fixation tip includes a hollow cylindrical housing and a custom designed stylet. The cylindrical housing attaches to a proximal end of the implantable lead. The stylet is inserted through the implant tool and into a lumen of the lead. The presence of the stylet, made from a length of relatively stiff wire, helps guide the distal tip of the lead to a desired implant location. The cylindrical housing includes a body portion and an end portion. The end portion is rotatable relative to the body portion. The stylet includes a knob on its proximal end, and also includes a stub pin slightly forward of its proximal end. The stub pin is received within a slot along the side of the cylindrical housing. Two spaced-apart recesses along the length of the slot allow the stub pin to be respectively held therein.

Abstract: An implantable arrhythmia treatment system includes a sensor which generates an electrical signal corresponding to a physiological characteristic of a patient, the physiological characteristics and thus the electrical signal exhibit a change given the onset of an arrhythmia. The electrical signal is supplied to a fibrillation detector in an implantable housing, which initiates an appropriate treatment sequence upon the detection of the onset of the arrhythmia. Simultaneously with initiating the treatment sequence, the fibrillation detector causes, either by direct connection or by telemetry communication, the generation of an alarm signal which informs the patient that the sequence has been initiated, so that the patient knows that a treatment pulse is about to be released. The implantable unit includes circuitry responsive to a signal externally generated by the patient which prevents the release of the defibrillating pulse. If the patient feels no need for such a pulse, i.e.

Abstract: A pacemaker having a single integrated interconnect structure is disclosed which combines the functions of a flexible interconnect cable and a protective lid for a hybrid substrate. The integrated interconnect structure is a molded three-dimensional part having a lid portion and a feedthrough portion. An electronic substrate can be mounted onto the integrated interconnect structure wherein electrical conductors formed within the integrated interconnect structure connect the electronic substrate to the battery terminals and to the pacemaker feedthroughs. In one embodiment, the integrated interconnect structure may be adapted to have additional electronic circuitry mounted directly onto a flat inner cavity within the lid portion, thereby enabling electronic components to be easily added or modified without complicating the assembly operations of the pacemaker.

Abstract: An implantable tachyarrhythmia control system includes a patch electrode having a sensor integrated therein, such as a piezoelectric sensor, which is capable of monitoring mechanical heart activity. When the patch electrode is sutured to the cardiac tissue, the piezoelectric sensor will be deformed due to the mechanical activity of the heart muscle, and will generate a corresponding electrical signal. The electrical signal from the sensor will exhibit relatively low-frequency periodicity and relatively low amplitude during normal heart activity. In the event of tachycardia or fibrillation, the signal will exhibit excursions beyond those occurring for normal heart activity, and will consequently have a higher energy content. The signal is thus an indicator for the onset of these cardiac events. The signal can be supplied to an implantable defibrillator and can be used as a primary or secondary trigger for initiating defibrillation therapy, such as one or more defibrillating pulses.

Abstract: A suture sleeve for securing the leads of a multiple lead implantable medical device includes lead gripping and anchoring portions. The sleeve has a pair of flexible side walls and longitudinally extending channels for receiving the leads. The side walls of at least the gripping portion have longitudinally extending, confronting, spaced apart edges and comprises two layers one of which is formed of a soft plastic such as silicone and the other of which is formed of a harder but flexible material such as polysulfone. Sutures placed and tied about the gripping portion compress the sleeve about the leads. Tightening of the sutures brings the confronting edges of the gripping portion of the sleeve into engagement thereby precluding further compression of the sleeve and preventing damage to the leads.

Abstract: A system and method for terminating a cardiac arrhythmia includes pacing means for stimulating the heart with at least one stimulation pulse during a narrow region of susceptibility (termination window) of the arrhythmia cycle. The location of the region of susceptibility is initially found by delivering the stimulation pulse(s) to the heart in accordance with a prescribed scan pattern. The scan pattern delivers the stimulation pulse(s) at a time during the cardiac cycle such that each successive stimulation pulse is presented to the heart at a slightly different time than was a prior stimulation pulse, thereby assuring that the region of susceptibility or termination window is eventually located. When the arrhythmia is successfully terminated, the location of the successful stimulation pulse within the prescribed scan pattern is stored.

Abstract: An implantable pacemaker having means for detecting and responding to a premature ventricular contraction (PVC), also includes circuit means for minimizing the likelihood of sensing a PVC when in fact a PVC has not occurred. The circuit means latches the occurrence of any atrial events sensed during the relative atrial refractory period of the pacemaker, whether such atrial events are noise or an early P-wave; and, in response to such latching, disables the PVC detection circuit until certain prescribed events occur, whereupon the PVC detection circuit is re-enabled. The prescribed events that re-enable the PVC detection circuit after it has been disabled include, e.g., the occurrence of a ventricular pulse or sensed R-wave. Further, in the event a PVC is detected and a desired PVC response is invoked, an additional circuit means automatically terminates the PVC response in the event the PVC response becomes stuck.

Abstract: A multi-contact connector system for electrically and mechanically connecting a lead for the delivery of electrical energy at a body site to an implantable source of the electrical energy includes a plug connector element carried at a proximal end of the lead which is received in a socket connector element carried on the source of electrical energy. The plug connector element is a radially expandable sleeve with a number of exteriorly exposed contacts respectively connected to conductors contained within the lead. Corresponding contacts are mounted in the interior of the socket connector element. The plug connector sleeve fits over a flexible expansion element contained in the socket connector element. The expansion element is operated by a toggle switch after the connector elements are engaged so as to radially expand.

Abstract: A multi-part molded pacemaker connector that meets the precise requirements imposed by the VS-1 standard, yet does not require complex or expensive machining of individual parts. Advantageously, the pacemaker connector is made from a plurality of individually molded parts, with each individual part being designed to readily allow the insertion of seals and other connector components, prior to joining the parts together. The connector includes three molded pieces: a body tip, a body ring, and an entrance connector which are adapted to be joined during assembly. The connector further includes a garter spring, and preferably, two annular sealing rings. A tip connector block is insert-molded into the body tip. A conductive tube, which forms the ring connector, is insert-molded within the entrance connector. The body ring provides appropriate spacing between the tip connector block and the ring connector.

Abstract: A self-adjusting rate-responsive pacemaker includes a conventional programmable pulse generator, a physiological sensor, and a processor, all packaged within an implantable case. The pulse generator generates heart stimulation pulses on demand, or as otherwise programmed, as controlled by a sensor-indicated rate signal. The sensor-indicated rate signal is derived from a raw signal obtained from the physiological sensor, and provides some indication of whether the heart rate should increase or decrease. The processor converts the raw signal to the sensor-indicated rate signal in accordance with a desired relationship (FIGS. 2, 3, 7A, 8). A minimum sensor signal value sets the minimum rate at which the pacemaker generates stimulation pulses, and a maximum sensor signal value sets the maximum rate at which the pacemaker generates stimulation pulses.

Abstract: A pacemaker mediated tachycardia (PMT) is detected by circuitry within an implantable pacemaker. The PMT is detected by first detecting a tachycardia condition that includes a prescribed number of consecutive cardiac cycles having a rate faster than a prescribed rate. Each cardiac cycle of the tachycardia condition includes a natural atrial event, i.e., a P-wave, and a paced ventricular event, i.e., a V-pulse generated by a pacemaker. After the prescribed number of such cardiac cycles, e.g., two to ten, a P-V delay in a single cardiac cycle is modified by a first prescribed amount, e.g., 50 milliseconds. The time interval of a V-P interval associated with at least one cardiac cycle preceding the modified P-V delay is then compared to a V-P interval immediately following the modified P-V delay. Only if the difference between the V-P intervals thus measured is less than a second prescribed amount, e.g., 25 milliseconds, is a PMT indicated. If a PMT is indicated, a PMT termination regimen, e.g.

Abstract: A ribbon conductor set and related method of production and installation are provided for electrically interconnecting components in an implantable medical device, such as a heart pacemaker unit or the like. The ribbon conductor set is formed by die cutting and/or stamping a thin plate of conductive material to define a plurality of conductor ribbons supported from a frame. The ribbon set and supporting frame are shaped for seated placement into a fixture to orient the conductor ribbons in predetermined array to extend between electrical components on the fixture, such as between connector blocks and feedthrough terminals of a heart pacemaker unit. The fixture thus supports the conductor ribbons for facilitated connection to the electrical components, such as by welding, after which the resultant subassembly may be further processed as by encapsulation within a cast epoxy head or the like.