Ventritex, Inc.

Pacesetter, Inc.

Benjamin Pless

Phillip L. Ball

Michael Sweeney

Roger Winkle

Eric Fain

Benjamin D. Pless

Richard Luceri

Anthony Wayne Nathan

Benjamin D Pless

Eric Steven Fain

Kenneth J Carroll

M Elizabeth Bush

Michael B Sweeney

Craig E Mar

William H Elias

John G Ryan

Phillip L Ball

Timothy A Fayram

Drew A Hoffmann

Drew Hoffman

Scott McCall

Steven M Mitchell

Anthony Nathan

Albert K Chin

Stephen T Archer

Rose Province

M Dean Matthews

Michael Hardage

James M Culp

Timothy A Marguit

Rose A Province

Samuel Parler

J Scott McCall

Sam Parler

A method for delivering cardiac therapy, particularly defibrillation therapy, using an implantable cardioverter-defibrillator (ICD) or other cardiac therapy device. The method can be used either alone or in conjunction with any other suitable defibrillation (or other cardiac) therapy regimen. If used in conjunction with a conventional or other suitable defibrillation therapy regimen, the method can be considered to precondition the heart in advance of delivery of the defibrillation shock(s), in order to reduce the defibrillation threshold (DFT), and thus reduce the overall energy required for delivery of effective defibrillation therapy. In either case, in accordance with the method, the voltage gradients (VGs) across a plurality of different regions of the heart are sensed, e.g., using an endocardial sensor array (ESA), and a respective plurality of electrograms (EGMs) are produced in respective EGM channels. The excitable gaps (i.e., the intervals between successive activations) in the different VG regions of the heart are then brought into phase alignment with one another by appropriately timing the delivery of electrical stimulation (e.g., one or more pulses). In this connection, either the timing of the next activation interval can be advanced by delivering an electrical stimulus (pulse) during the excitable gap or in the late repolarization phase of the previous activation, or the activation interval can be extended by delivering an electrical stimulus earlier in the repolarization phase of the previous activation, leading to an extension of the refractory period (i.e., RPE). If three or more EGM channels are used, the excitable gaps in the different VG regions are preferably brought into phase with one another by first bringing the region associated with the near-field EGM channel into phase alignment with the region associated with the EGM channel of the adjacent (next highest) VG region and then successively entraining the thusly entrained regions with the regions associated with the EGM channels corresponding to the successively more distant VG regions, until the regions associated with all EGM channels are brought into phase alignment with one another. Also disclosed is a cardiac therapy device (e.g., an ICD) for implementing this method.

Method for delivering cardiac therapy and a cardiac therapy device for implementing the same

A method of manufacturing a capacitor for use in an implantable cardiac defibrillator by forming a set of conductive sheets with the same profile having a sacrificial portion. An alignment figure is formed in each sheet, and the sheets are stacked and aligned by registering the alignment figures with each other. The sacrificial portions are removed from each of the sheets, which are secured together and positioned in a capacitor housing. Each sheet may include two major portions joined by the sacrificial portion, so that each major portion may become part of a separate capacitor stack after the sacrificial portion is removed, doubling manufacturing throughput.

Capacitor for an implantable cardiac defibrillator

A method for making anode foil plates for use with layered electrolytic capacitors and capacitors made with such plates. A high purity aluminum foil is provided for generation of anode foil plates. Sheets of the foil are highly etched to provide a very high surface area. Following the etch process, the foil is partially cut or punched into plates from the etched sheets in the general shape of the finished capacitor housing with a portion remaining connected to the supporting foil. The supporting foil with the partially punched-out etched plates are subjected to a forming process by applying a voltage to the plates in the presence of an electrolyte to provide formed anode foil plates with edges which do not have to be reformed during capacitor aging and which do not have any particulates at cut edges. The formed anode plates are layered with cathode plates and separators in a capacitor housing with an electrolyte to provide a finished capacitor.

Method for making anode foil for layered electrolytic capacitor and

A capacitor for an implantable cardiac defibrillator with a housing defining a chamber. A plurality of flat, stacked, charge storing layers reside within the chamber. Each of the layers includes at least a first and a second electrically conductive sheets separated by a sheet in between. The first sheet is electrically connected to the housing, and the second sheet is electrically isolated from the housing. The layers each have a periphery having at least one alignment element, with the second sheet extending to the periphery along at least a portion of the alignment element, such that the layers may be engaged at the alignment element to register the layers during assembly.

Layered capacitor with alignment elements for an implantable cardiac

A capacitor optimized for use in an implantable medical device such as an implantable defibrillator is disclosed. In its simplest form, the capacitor comprises a thin planar dielectric sheet that has an array of cells open to one or both sides. Metallization is applied to the surface of the cells such that the walls of adjacent cells form a capacitor with the wall that separates the cells serving as the dielectric. The metallization pattern that forms the electrical connection to the cells may be patterned to limit the allowable current flow to each individual cell, thereby providing a fuse in the case of local dielectric failure.

Micro-cellular capacitor for use in implantable medical devices

A high voltage charger operates in a three-phase cycle. In a first phase, the high voltage charger operates at a fixed frequency. In a second phase, the high voltage charger operates at a variable frequency designed to draw a substantially constant average current from a power source. In the third phase, the high voltage charger returns to fixed frequency operation. The variable frequency is the reciprocal of the sum of an on-time and an off-time of the switch. In one embodiment, the on-time is provided by the time required for the switch to reach a predetermined maximum and the off-time is provided by the time over which a magnetic field in a transformer collapses.

High voltage charger

A lead system for use with an implantable cardioverter/defibrillator is disclosed. The lead system includes a fixation hook positioned approximately half-way between the distal tip of the lead and the tricuspid valve. The distal tip of the lead is positioned at the apex of the right ventricle and may or may not be secured there by a second fixation means such as a screw tip or tines. The fixation hook allows the defibrillation electrode to be accurately positioned by the patient's surgeon and maintained in contact with the septum wall of the patient's heart. By providing such intimate contact between the defibrillation electrode and the septum wall, defibrillation thresholds are reduced.

Endocardial lead system with defibrillation electrode fixation

A lead system for use with an implantable pacemaker/cardioverter/defibrillator. The lead system includes a securable pace/sense electrode positioned between the distal tip of the lead and the tricuspid valve. The distal tip of the lead is positioned at the apex of the right ventricle and may or may not be secured there by a second fixation means such as a screw tip or tines. The securable pace/sense electrode allows the defibrillation electrode to be accurately positioned by the patient's surgeon and maintained in intimate contact with the septum wall of the patient's heart, thereby reducing defibrillation thresholds; it provides a sense signal from the region of the His bundle or AV node, which can be used with other electrodes to distinguish between various arrhythmias; and it provides more physiologic pacing leading to greater cardiac output.

Lead with septal defibrillation and pacing electrodes

A method and apparatus for inducing fibrillation in a patient's heart by delivering a direct current stimulus to the heart from a DC-to-DC converter. The hardware of a conventional implantable cardioverter/defibrillator (ICD) is utilized with a modification to the control algorithms. Particularly, when it is desired to induce fibrillation in a patient's heart, typically during ICD implant defibrillation threshold (DFT) testing, a command is delivered from an external instrument to the ICD to deliver the fibrillation shock. The DC-to-DC converter which is normally used to charge the ICD high voltage capacitors is activated and immediately thereafter or following a short period to allow the high voltage capacitors to charge, the high voltage output switches of the output stage are closed. This delivers the output current from the DC-to-DC converter to the defibrillation electrodes and through the patient's heart. This stimulus is continued for a predetermined time of between about 30 milliseconds to 5 seconds. At that point the output switches are opened and the converter is shut off. This DC stimulus delivered directly to the patient's heart induces fibrillation.

Apparatus and method for inducing fibrillation

A pulse generator having a housing for enclosing and containing pulse generator defibrillation circuitry, particularly adapted to allow for ease of manufacture and use, is disclosed. At least one surface of the housing is electrically conductive and connected to the pulse generator circuitry for delivering defibrillating energy to the heart. The defibrillator is provided with a case activating lead connector cavity having two connector blocks. By plugging in a lead with a pin long enough to contact the only first connector block, the lead becomes active. Using a plug with a longer pin to contact both blocks activates the can. To use neither a lead in the case activating port, nor an active can, a plug with a short or nonconductive pin may be used to plug the cavity without activating the can. By using this system, various electrode configurations can be used as required to provide the optimum system for a given patient. The pulse generator housing is preferably implanted in the left pectoral region proximate the heart with the conductive surface facing the heart. Other implantable electrodes are discharged against the pulse generator housing electrode.

Pulse generator with case that can be active or inactive

An implantable defibrillator lead comprises a flexible core onto which is wound helically wound coils to form an electrode. These electrode coils are partially encapsulated by a flexible matrix which holds them in their wrapped position around the core. Due to its coiled coil structure, this electrode provides improved flexibility, and can be used endocardially, intravascularly, epicardially, or subcutaneously. The electrode may function alternately as a defibrillation electrode and as a sensing electrode in a lead with a separate pacing electrode.

Method of making flexible defibrillation electrode

A programmable implantable medical device utilizable for delivering a configurable defibrillation waveform to a patient's 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 biphasic waveform such that the first phase of the defibrillation waveform has programmed tilt and the second phase has a duration which is a function of the duration of the first phase.

Method and apparatus for producing configurable biphasic defibrillation

The present invention provides an apparatus and method for cardiac defibrillation which utilizes a lower voltage defibrillation output to depolarize the myocardial cells by providing a rapid sequence of defibrillation shocks synchronized with sensed sequential cardiac events or features during an arrhythmia. Each shock may be a conventional monophasic or biphasic pulse. Each of the shocks may be relatively short in duration, i.e. on the order of 0.5 to 3 milliseconds or may be relatively long, i.e. up to about 100 milliseconds. The amplifiers of the sensing circuitry are particularly adapted quickly recover to after each shock is delivered to allow synchronization of the next shock to the next cardiac feature. This is accomplished by using broad band amplifiers which have DC-baseline restoration capability in order to eliminate offsets caused by a preceding shock. A microprocessor in the pulse generator delivers a programmed number of pulses synchronized to the ECG. If a first sequence fails to terminate the arrhythmia, another sequence is delivered at a higher voltage and/or additional pulses are added to the sequence.

Method and apparatus for treating cardiac tachyarrhythmia

A lead for use with an implantable cardioverter/defibrillator system is disclosed. In the preferred embodiment, the lead combines a right ventricular endocardial electrode, a superior vena cava electrode and one or more atrial sensing electrodes on a single catheter lead. The distal end of the lead is transvenously implanted, typically through an incision in the cephalic or subclavian vein. The proximal end of the lead is then tunneled below the fascia to the location of the pulse generator. Ventricular sensing and/or pacing electrode(s) may also be included at the distal end of the combined lead to provide ventricular intracardiac electrogram sensing and bradycardia pacing.

Growing community of inventors

Menlo Park, CA, United States of America

Benjamin D Pless