Patents by Inventor Luke J. Christenson

Luke J. Christenson has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6684102
    Abstract: 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.
    Type: Grant
    Filed: November 3, 2000
    Date of Patent: January 27, 2004
    Assignee: Cardiac Pacemakers, Inc.
    Inventors: Michael J. O'Phelan, Robert R. Tong, Luke J. Christenson
  • Patent number: 6597564
    Abstract: 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.
    Type: Grant
    Filed: June 19, 2001
    Date of Patent: July 22, 2003
    Assignee: Cardiac Pacemakers, Inc.
    Inventors: Michael J. O'Phelan, Robert R. Tong, James M. Poplett, Luke J. Christenson, Alexander Gordon Barr, Brian V. Waytashek
  • Patent number: 6556863
    Abstract: 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.
    Type: Grant
    Filed: October 2, 1998
    Date of Patent: April 29, 2003
    Assignee: Cardiac Pacemakers, Inc.
    Inventors: Michael J. O'Phelan, Luke J. Christenson, James M. Poplett, Robert R. Tong
  • Publication number: 20020133209
    Abstract: 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.
    Type: Application
    Filed: February 26, 2002
    Publication date: September 19, 2002
    Applicant: Cardiac Pacemakers, Inc.
    Inventors: Michael J. O'Phelan, Robert R. Tong, Luke J. Christenson, Steven A. Rubin
  • Patent number: 6426864
    Abstract: 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.
    Type: Grant
    Filed: June 29, 2000
    Date of Patent: July 30, 2002
    Assignee: Cardiac Pacemakers, Inc.
    Inventors: Michael J. O'Phelan, Luke J. Christenson, James M. Poplett, Robert R. Tong
  • Patent number: 6421226
    Abstract: 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.
    Type: Grant
    Filed: June 29, 2000
    Date of Patent: July 16, 2002
    Assignee: Cardiac Pacemakes, Inc.
    Inventors: Michael J. O'Phelan, Luke J. Christenson, James M. Poplett, Robert R. Tong
  • Patent number: 6385490
    Abstract: 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.
    Type: Grant
    Filed: June 30, 2000
    Date of Patent: May 7, 2002
    Assignee: Cardiac Pacemakers, Inc.
    Inventors: Michael J. O'Phelan, Robert R. Tong, Luke J. Christenson, Steven A. Rubin
  • Publication number: 20020034062
    Abstract: 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.
    Type: Application
    Filed: June 19, 2001
    Publication date: March 21, 2002
    Applicant: Cardiac Pacemakers, Inc.
    Inventors: Michael J. O'Phelan, Robert R. Tong, James M. Poplett, Luke J. Christenson, Alexander Gordon Barr, Brian V. Waytashek
  • Patent number: 6249423
    Abstract: 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.
    Type: Grant
    Filed: April 21, 1998
    Date of Patent: June 19, 2001
    Assignee: Cardiac Pacemakers, Inc.
    Inventors: Michael J. O'Phelan, Robert R. Tong, James M. Poplett, Luke J. Christenson, Alexander Gordon Barr, Brian V. Waytashek