Devices for adapting charge initiation for an implantable cardioverter-defibrillator

• US 8,229,563 B2
• Filed: 01/25/2005
• Issued: 07/24/2012
• Est. Priority Date: 01/25/2005
• Status: Active Grant

• Current Assignee: Cameron Incorporated (Schlumberger NV)
• Original Assignee: Cameron Incorporated (Schlumberger NV)
• Inventors: Warren, Jay A., Bardy, Gust H.
• Primary Examiner(s): Layno, Carl H
• Assistant Examiner(s): OROPEZA, FRANCES P
• Application Number:
  US11/043,012
• Publication Number:
  US 20060167504A1
• Time in Patent Office: 2,737 Days
• Field of Search: 600/373, 600/374, 600/377, 600/393, 600/509, 600/515, 600/516, 600/518, 600/519, 600/521, 607/4, 607/5, 607/7, 607/9, 607/11, 607/14, 607/15, 607/25, 607/27, 607/28, 607/34, 607/116, 607/119, 607/122, 607/123
• US Class Current: 607/34
• CPC Class Codes: A61N 1/3943 for threshold determination
• CPC Class Codes: A61N 1/3956 Implantable devices for applying electric shocks to the heart, e.g. for cardioversion

Abstract

Devices configured to perform an adaptive method for initiating charging of high power capacitors and delivering therapy to a patient after the patient experiences a non-sustained arrhythmia. The adaptive methods adjust persistence criteria used to analyze an arrhythmia prior to initiating a charging sequence to deliver therapy.

Claims

1. An implantable cardiac rhythm management device comprising an energy storage system configured for delivering cardiac stimulus to a patient, operational circuitry, and at least first and second electrodes for delivering cardiac stimulus to a patient, the operational circuitry configured to perform the steps of:

determining that cardiac stimulus is indicated at a first time and initiating a charging operation for the energy storage system in response to determining that the cardiac stimulus is indicated by reference to a therapy threshold used to determine whether cardiac stimulus is indicated;

determining whether the cardiac stimulus is no longer indicated at a second time after the first time but prior to delivery of the indicated cardiac stimulus and, if so, stopping the charging operation and changing the therapy threshold to render the therapy threshold more difficult to pass for a future cardiac rhythm or, if not, discharging the energy storage system via the electrodes to deliver therapy; and

wherein the operational circuitry is configured such that the therapy threshold is an X-out-of-Y threshold calling for an initial value of 18/24 and wherein, if the therapy threshold is made more difficult to pass, the X-out-of-Y threshold is modified to 21/27.

2. The implantable cardiac rhythm management device of claim 1, wherein the operational circuitry is configured such that the second time occurs prior to completion of the charging operation.

3. The implantable cardiac rhythm management device of claim 1, wherein the operational circuitry is configured such that the second time occurs after completion of the charging operation.

4. The implantable cardiac rhythm management device of claim 1, wherein the operational circuitry is configured such that the step of determining whether the cardiac stimulus is no longer indicated at a second time after the first time but prior to delivery of the indicated cardiac stimulus is performed repeatedly during the charging operation.

5. The implantable cardiac rhythm management device of claim 4, wherein the operational circuitry is configured such that, if the cardiac stimulus continues to be indicated during the charging operation, the determining step is performed at least once after the charging operation is completed.

6. An implantable cardiac rhythm management device comprising an energy storage system configured for delivering cardiac stimulus to a patient, operational circuitry, and at least first and second electrodes for delivering cardiac stimulus to a patient, the operational circuitry configured to perform the steps of:

determining that cardiac stimulus is indicated at a first time and initiating a charging operation for the energy storage system in response to determining that the cardiac stimulus is indicated by reference to a therapy threshold used to determine whether cardiac stimulus is indicated;

determining whether the cardiac stimulus is no longer indicated at a second time after the first time but prior to delivery of the indicated cardiac stimulus and, if so, stopping the charging operation and changing the therapy threshold to render the therapy threshold more difficult to pass for a future cardiac rhythm or, if not, discharging the energy storage system via the electrodes to deliver therapy; and

wherein the operational circuitry is configured such that the therapy threshold includes;

an X-out-of-Y threshold calling for an initial value of 18/24; and

a persistence threshold calling for the X-out-of-Y threshold to be maintained for at least two consecutive iterations of analysis;

wherein, if the therapy threshold is made more difficult to pass, the persistence threshold is increased by three to require five consecutive iterations of analysis.