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US 7,890,163 B2Granted
Method and apparatus for detecting fibrillation using cardiac local impedance
AssigneeCardiac Pacemakers, Inc.
InventorAndres Belalcazar
Life of this patent
Estimating the term…
Abstract
A cardiac rhythm management (CRM) system detects tachyarrhythmia using cardiac local impedance indicative of cardiac local wall motion. A cardiac local impedance signal indicative of an impedance of a cardiac region is sensed by using a pair of bipolar electrodes placed in that cardiac region. Tachyarrhythmia such as VF is detected by analyzing one or more cardiac local impedance signals sensed in one or more cardiac regions.
Claims25
A cardiac rhythm management system for treating a heart, the system comprising:
- an implantable medical device configured to be coupled to an implantable lead including a pair of impedance sensing electrodes configured to be placed in the heart to sense a cardiac local impedance signal indicative of a cardiac local wall motion, the implantable medical device including:
- an impedance sensing circuit adapted to sense the cardiac local impedance signal using the pair of impedance sensing electrodes;
- and
- an impedance-based tachyarrhythmia detector adapted to detect a predetermined-type tachyarrhythmia using the cardiac local impedance signal, the impedance-based tachyarrhythmia detector including an impedance-based ventricular fibrillation (VF) detector including:
- a detection zone generator adapted to produce a VF detection zone specified by one or more threshold amplitudes;
- and
- a comparator including a signal input to receive the cardiac local impedance signal, one or more threshold inputs to receive the one or more threshold amplitudes, and an output to indicate a VF detection when the amplitude of the cardiac local impedance signal falls into the VF detection zone.
4 more elements
A cardiac rhythm management system for treating a heart, the system comprising:
- an implantable medical device configured to be coupled to an implantable lead including a pair of impedance sensing electrodes configured to be placed in the heart to sense a cardiac local impedance signal indicative of a cardiac local wall motion, the implantable medical device including:
- an impedance sensing circuit adapted to sense the cardiac local impedance signal using the pair of impedance sensing electrodes, the impedance sensing circuit including a differentiator adapted to produce a cardiac local impedance derivative signal using the cardiac local impedance signal, the cardiac local impedance derivative signal indicative of a rate of change in the cardiac local impedance;
- and
- an impedance-based tachyarrhythmia detector adapted to detect a predetermined-type tachyarrhythmia using the cardiac local impedance derivative signal, the impedance-based tachyarrhythmia detector including an impedance-based ventricular fibrillation (VF) detector including:
- a detection zone generator adapted to produce a VF detection zone specified by one or more threshold amplitudes;
- and
- a comparator having a signal input to receive the cardiac local impedance derivative signal, one or more threshold inputs to receive the one or more threshold amplitudes, and an output to indicate a VF detection when the amplitude of the cardiac local impedance derivative signal falls into the VF detection zone.
4 more elements
A cardiac rhythm management system for treating a heart, the system comprising:
- an implantable medical device configured to be coupled to an implantable left ventricular (LV) lead including a pair of LV impedance sensing electrodes configured to be placed on the heart to sense an LV local impedance signal (LVZ) indicative of an LV local wall motion, the implantable medical device including:
- an LV impedance sensing circuit adapted to sense the LVZ using the LV impedance sensing electrodes;
- and
- an impedance-based tachyarrhythmia detector adapted to detect a predetermined-type tachyarrhythmia using the LVZ.
1 more element
Dependencies are inferred from the claim text.