Adaptive Confirmation of Treatable Arrhythmia in Implantable Cardiac Stimulus Devices
First Claim
1. A method of operation in an implantable cardiac stimulus device (ICSD) comprising a housing that contains a battery power source and operational circuitry that operates by analyzing cardiac signals from implanted electrode(s) in order to determine whether a treatable arrhythmia is detected, the method comprising:
- the ICSD making an initial determination that a treatable condition is occurring;
the ICSD preparing to deliver therapy in response to the initial determination and, while preparing to deliver therapy, observing whether indications of benign cardiac rhythm are detected;
when the ICSD is prepared to deliver therapy, applying Confirmation criteria to confirm the treatable condition is ongoing; and
if the Confirmation criteria are met, delivering therapy from the ICSD;
wherein the method comprises the ICSD changing the Confirmation criteria in response to identification of one or more indications of a benign cardiac rhythm while the ICSD is preparing to deliver therapy.
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Accused Products
Abstract
Methods and devices for adjusting therapy delivery decisions in an implantable cardiac stimulus device by observing cardiac activity following an initial identification of a treatable condition. In some examples, cardiac activity that appears benign is quantified and a therapy confirmation threshold is adjusted according to how much apparently benign cardiac activity is seen after an initial identification of a treatable condition. In other examples, a new threshold is applied following the initial identification of treatable condition, removing historical data preceding the initial identification from subsequent therapy delivery decisions.
106 Citations
27 Claims
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1. A method of operation in an implantable cardiac stimulus device (ICSD) comprising a housing that contains a battery power source and operational circuitry that operates by analyzing cardiac signals from implanted electrode(s) in order to determine whether a treatable arrhythmia is detected, the method comprising:
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the ICSD making an initial determination that a treatable condition is occurring; the ICSD preparing to deliver therapy in response to the initial determination and, while preparing to deliver therapy, observing whether indications of benign cardiac rhythm are detected; when the ICSD is prepared to deliver therapy, applying Confirmation criteria to confirm the treatable condition is ongoing; and if the Confirmation criteria are met, delivering therapy from the ICSD; wherein the method comprises the ICSD changing the Confirmation criteria in response to identification of one or more indications of a benign cardiac rhythm while the ICSD is preparing to deliver therapy. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. An implantable cardiac stimulus device (ICSD) comprising a housing that contains a battery power source and operational circuitry that operates by analyzing cardiac signal data from implanted electrodes in order to determine whether a treatable arrhythmia is detected, ICSD configured to perform a method of verifying therapy delivery comprising:
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the ICSD making an initial determination that a treatable condition is occurring; after making an initial determination that a treatable condition is occurring, the ICSD preparing to deliver therapy; while the ICSD is preparing to deliver therapy, observing whether indications of benign cardiac rhythm are detected; when the ICSD is prepared to deliver therapy, applying Confirmation criteria to ensure the treatable condition is ongoing; and if the Confirmation criteria are met, delivering therapy from the ICSD; wherein the method comprises changing the Confirmation criteria in response to identification of one or more indications of a benign cardiac rhythm while the ICSD is preparing to deliver therapy. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. An implantable cardiac stimulus device (ICSD) that operates by analyzing cardiac signal data from implanted electrodes in order to determine whether a treatable arrhythmia needs therapy by:
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detecting cardiac events using the implanted electrodes; establishing an X/Y Counter with X indicating a number of Treatable detected events out of a set of Y detected events; and determining whether the X/Y Counter meets at least a Therapy threshold condition and, if so, the ICSD determining that a treatable arrhythmia needs therapy and beginning to prepare for therapy delivery; wherein the ICSD is also configured to perform a method of verifying therapy delivery when the ICSD begins to prepare for therapy delivery, the method of verifying therapy delivery comprising; resetting the X/Y counter; detecting cardiac events and refilling the X/Y counter while the ICSD prepares to deliver therapy; determining that the ICSD is ready to deliver therapy; once the ICSD is ready to deliver therapy, if the X/Y counter exceeds a Confirmation threshold condition, delivering therapy;
or, if not, waiting for additional cardiac events. - View Dependent Claims (21, 22, 23, 24, 25, 26)
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27. An implantable cardiac stimulus device (ICSD) comprising a canister housing operational circuitry for the ICSD, the operational circuitry including a defibrillation capacitor for storing defibrillation energy and a charging circuit for charging the defibrillation capacitor to a therapeutic energy level, the canister including at least one electrode thereon, and a lead electrode coupled to the canister and carrying electrodes coupled to the operational circuitry, the operational circuitry being configured to perform a method comprising:
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capturing cardiac signals from the electrodes; determining that a tachyarrhythmia or fibrillation is occurring and needs therapy; activating the charging circuit to charge the defibrillation capacitor; detecting cardiac events after the charging circuit is activated and keeping a long interval count by; a) establishing an initial value for the long interval count when the charging circuit is activated, and b) incrementing the long interval count when a long interval between two detected cardiac events occurs, or c) decrementing the long interval count when a short interval between two detected cardiac events occurs, the decrementing step being limited by the initial value; determining whether charging is complete, and, if so, determining whether a Confirmation condition is met, the Confirmation condition requiring a series of detected events to indicate therapy delivery, wherein the series has a length defined by the long interval count, and if so, delivering therapy to the patient.
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Specification