Cardiac Pacemakers, Inc.

Luke J Christenson

Robert R Tong

Michael J O'Phelan

James M Poplett

Brian V Waytashek

Alexander Gordon Barr

Brian L Schmidt

Gregory J Sherwood

Richard J Kavanagh

Brian D Schenk

Rajesh Iyer

Steven A Rubin

One aspect provides a capacitor feedthrough assembly having an electrically conductive member dimensioned to extend at least partially through a feedthrough hole of a case of the capacitor, the conductive member having a passage therethrough.

Flat capacitor for an implantable medical device

Implantable defibrillators are implanted into the chests of patients prone to suffering ventricular fibrillation, a potentially fatal heart condition. A critical component in these devices is an aluminum electrolytic capacitor, which stores and delivers life-saving bursts of electric charge to a fibrillating heart. To reduce capacitor size, manufacturers have developed special aluminum foils, such as core-etched and tunnel-etched aluminum foils. Unfortunately, core-etched foils don't work well in multiple-anode capacitors, and tunnel-etched foils are brittle and tend to break when making some common types of capacitors. Accordingly, the inventors devised a new foil structure having perforations and cavities. In an exemplary embodiment, each perforation and cavity has a cross-sectional area, with the perforations having a larger, for example, 2 to 100 times larger, average cross-sectional area than the cavities. Other embodiments of the invention include foil assemblies, capacitors, and implantable defibrillators that benefit from properties of the new foil structure.

High-energy capacitors for implantable defibrillators

Implantable heart-monitoring devices, such as defibrillators, pacemakers, and cardioverters, detect abnormal heart rhythms and automatically apply corrective electrical therapy, specifically one or more bursts of electric charge, to abnormally beating hearts. Critical parts in these devices include the capacitors that store and deliver the bursts of electric charge. Some devices use cylindrical aluminum electrolytic capacitors which include terminals that extend from one end of the case, making the capacitor longer and generally necessitating use of larger device housings. Accordingly, the inventors devised capacitor connection structures that allow size reduction. One exemplary capacitor includes two conductive endcaps at opposite ends of its capacitive element, instead of two upright terminals at one end, thereby allowing reduction in the height or volume of the capacitor and/or increases in the dimensions of other components, such as aluminum foils. Other aspects of the invention include heart-monitoring devices that incorporate these capacitors.

Implantable heart monitors having capacitors with endcap headers

One aspect provides a capacitor having a first stack of capacitive elements a second stack of capacitive elements, wherein the first and second stacks are enclosed in separate compartments of a capacitor case that electrically isolate the electrolytes of each stack from one another.

Implantable defibrillators are implanted into the chests of patients prone to suffering ventricular fibrillation, a potentially fatal heart condition. A critical component in these devices is an aluminum electrolytic capacitors, which stores and delivers one or more life-saving bursts of electric charge to a fibrillating heart. To reduce the size of these devices, capacitor manufacturers have developed special aluminum foils, for example core-etched and tunnel-etched aluminum foils. Unfortunately, core-etched foils don't work well in multiple-anode capacitors, and tunnel-etched foils are quite brittle and tend to break when making some common types of capacitors. Accordingly, the inventors devised a new foil structure having one or more perforations and one or more cavities with a depth less than the foil thickness. In an exemplary embodiment, each perforation and cavity has a cross-sectional area, with the perforations having a larger, for example, 2 to 100 times larger, average cross-sectional area than the cavities. Other embodiments of the invention include foil assemblies, capacitors, and implantable defibrillators that benefit from properties of the new foil structure.

High-energy electrolytic capacitors for implantable defibrillators

A multi-anodic aluminum electrolytic capacitor includes an electrical connection to the multiple porous (e.g., tunnel-etched) anodes in an anode stack using a single anode tab that is attached only to a first anode. Other anodes are electrically coupled to the anode tab through the first anode. Anodes in the anode stack are in intimate physical and electrical contact with other such anodes as a result of layering effected by planar stacking or cylindrical winding. The need for separate tabs to different anode layers is eliminated or at least minimized, thereby reducing capacitor volume, increasing capacitor reliability, and reducing the cost and complexity of the capacitor manufacturing process for multi-anodic capacitors. The capacitor is capable of use in implantable defibrillators, camera photoflashes, and other electric circuit applications.

Electrolytic capacitor and multi-anodic attachment

Implantable defibrillators are implanted into the chests of patients prone to suffering ventricular fibrillation, a potentially fatal heart condition. Critical components in these devices are aluminum electrolytic capacitors, which store and deliver one or more life-saving bursts of electric charge to a fibrillating heart. These capacitors make up about one third the total size of the defibrillators. Unfortunately, manufacturers of these capacitors have paid little or no attention to reducing the size of these capacitors through improved capacitor packaging. Accordingly, the inventors devised a unique capacitor lid, or header, assembly that allows size reduction. Specifically, one embodiment of the header assembly includes two recesses, each with a depth that allows the head of a rivet (or other fastener) to be substantially flush, or coplanar, with the underside of the header. Another embodiment includes a single recess to receive two rivet heads. The recesses reduce the vertical space necessary to ensure separation of the rivets from internal components of the capacitor and thus allow reduction in the overall height of the capacitor and size of devices, such as implantable defibrillators, that use them.

Capacitors with recessed rivets allow smaller implantable defibrillators

One embodiment includes a capacitor having a first anode stack having a first number of anode foils, a second anode stack having a second number of anode foils, where the first number of anode foils is different than the second number of anode foils. Another aspect provides a capacitor having a case having a curved interior surface, and first, second, and third capacitor modules that confront the curved interior surface of the case. One aspect provides a capacitor having one or more anodes and a cathode structure comprising a plurality of integrally connected cathode plates, the cathode structure having a serpentine shape, interweaving under and over each of the one or more anodes. One aspect provides a feedthrough assembly having an electrically conductive member dimensioned to extend at least partially through a feedthrough hole of a case of the capacitor, the conductive member having a passage therethrough. One aspect provides a capacitor having a first stack of capacitive elements a second stack of capacitive elements, wherein the first and second stacks are enclosed in separate compartments of a capacitor case that electrically isolate the electrolytes of each stack from one another. One aspect provides a capacitor case including a portion having opposing interior and exterior surfaces, with the portion having a hole; and a semi-permeable membrane adjacent the hole to regulate passage of fluids through the hole.

Implantable heart-monitoring devices, such as defibrillators, pacemakers, and cardioverters, detect onset of abnormal heart rhythms and automatically apply corrective electrical therapy, specifically one or more bursts of electric charge, to abnormally beating hearts. Critical parts in these devices include the capacitors that store and deliver the bursts of electric charge. Some devices use cylindrical aluminum electrolytic capacitors which include terminal that extend from one end of the case, making the capacitor longer than it otherwise would be and generally necessitating use of larger implantable device housings. Accordingly, the inventors devised unique capacitor connection structures that allow size reduction. One exemplary capacitor includes two conductive endcaps at opposite ends of its capacitive element, instead of two upright terminals at one end, thereby allowing reduction in the height or volume of the capacitor and/or increases in the dimensions of other components, such as aluminum foils. Other aspects of the invention include heart-monitoring devices that incorporate the unique capacitors.

Growing community of inventors

White Bear Lake, MN, United States of America

Luke J Christenson