Prioritized rule based method and apparatus for diagnosis and treatment of arrhythmias

• US 6,259,947 B1
• Filed: 07/20/1999
• Issued: 07/10/2001
• Est. Priority Date: 03/30/1995
• Status: Expired due to Term

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Kaemmerer, William F., Brown, Mark L., Olson, Walter H.
• Primary Examiner(s): Evanisko, George R.
• Application Number:
  US09/357,601
• Time in Patent Office: 721 Days
• Field of Search: 607/4, 607/5, 607/9, 607/14
• US Class Current: 607/4
• CPC Class Codes: A61B 5/283 Invasive
• CPC Class Codes: A61B 5/29 for permanent or long-term implantation
• CPC Class Codes: A61B 5/361 Detecting fibrillation
• CPC Class Codes: A61B 5/363 Detecting tachycardia or bradycardia
• CPC Class Codes: A61B 5/7264 Classification of physiological signals or data, e.g. using neural networks, statistical classifiers, expert systems or fuzzy systems neural networks per se G06N3/00; expert systems per se G06N5/00
• CPC Class Codes: A61N 1/3622 comprising two or more electrodes co-operating with different heart regions
• CPC Class Codes: G16H 50/20 for computer-aided diagnosis, e.g. based on medical expert systems

Abstract

An implantable antiarrhythmia device which detects and classifies arrhythmias of the human heart, and delivers appropriate therapy. The device employs a method of arrhythmia classification based on a set of prioritized rules, each of the rules defining a plurality of criteria based upon characteristics of sensed depolarizations of heart tissue, each rule being met when the criteria associated with the rule are met. Some rules, when met, trigger delivery of antiarrhythmia therapy. Other rules, when met, inhibit delivery of antiarrhythmia therapy. The rules may be met simultaneously, and if so, the highest priority rule governs the behavior of the device.

Claims

1. An anti-arrhythmia device comprising:

means for sensing depolarizations of heat tissue;

means for defining a set of prioritized rules, each of said rules defining one or more criteria based upon characteristics of said sensed depolarizations of heart tissue, each said rule being met when the criteria of said rule are met, said rules defined such that at least a first one and a second one of said rules are capable of being simultaneously met, at least said first one of said rules when met indicating need for delivery of an anti-arrhythmia therapy, at leas said second one or said rules when met indicating that anti-arrhythmia therapy should not be delivered;

means for analyzing said characteristics of said sensed depolarizations to determine which of said first and second rules are met, said analyzing means comprising means responsive to any one of said first and second rules being met for determining thereafter that the rule that is met is no longer met only after a plurality of sensed depolarizations fail to meet one of the criteria of the rule;

means operable when the criteria for both the first and second rules are met for determining the highest priority one of said first and second rules which are met; and

means responsive to a determination that said first one of said first and second rules that is met constitutes the highest priority rule met for triggering delivery of an anti-arrhythmia therapy.

5. An anti-arrhythmia device according to claim 1 or claim 2 or claim 3 or claim 4, wherein:

said sensing means comprises means for sensing depolarizations of two heart chambers; and

wherein said rule of defining means comprises means for assigning beat codes to intervals between successive depolarizations of one of said heart chambers based on occurrences of depolarizations of the other of said heart chambers therebetween, means for defining a set of allowed sequences of said beat codes indicative of a heart rhythm and means for defining a rule comprising a beat sequence criterion corresponding to a predetermined number of beat codes successively falling within said allowed sequences; and

wherein said analyzing means comprises means for counting the number of sequential beat codes which fall within said defined set of allowed sequences and for determining that said criterion is met in response to said counted number exceeding said predetermined number and means responsive to a rule within said set of prioritized rules employing said beat sequence criterion being met for determining thereafter that said rule is no longer met only after a plurality of sensed depolarizations fail to meet said beat sequence criterion.

6. A device according to claim 5 wherein said counting means further comprises means for decrementing said counted number in response to beat codes which do not fall within said defined set of sequences.

7. A device according to claim 6 wherein said decrementing means comprises means for resetting said counted number to a preset value in response to beat codes which do not fall within said defined set of sequences.

8. A device according to claim 6 wherein said decrementing means comprises means for decrementing said counted number by a preset decrement in response to a beat codes which do not fall within said defined set of sequences.

2. An anti-arrhythmia device comprising:

means for sensing depolarizations of heart tissue;

means for defining a set of prioritized rules, each of said rules defining one or more criteria based upon characteristics of said sensed depolarizations of heart tissue, each said rule being met when the criteria of said rule are met, said rules defined such that at least a first one and a second one of said rules are capable of being simultaneously met, at least said first one of said rules when met indicating need for delivery of an anti-arrhythmia therapy, at least said second one or said rules when met indicating that anti-arrhythmia therapy should not be delivered;

means for analyzing said characteristics of said sensed depolarizations to determine which of said first and second rules are met, said analyzing means comprising means responsive to any one of said first and second rules being met for determining thereafter that the rule that is met is no longer met only after a plurality of sensed depolarizations fail to meet one of the criteria of that rule;

means operable when the criteria for both the first and second rules are met for determining the highest priority one of said first and second rules which are met; and

means responsive to a determination that said second one of said first and second rules that is met constitutes the highest priority rule met for preventing delivery of an anti-arrhythmia therapy.

3. An anti-arrhythmia device comprising:

means for sensing depolarizations of heart tissue;

means for defining a set of prioritized rules, each of said rules defining one or more criteria based upon characteristics of said sensed depolarizations of heart tissue, each said rule being met when the criteria of said rule are met, said rules defined such that at least a first one and a second one of said rules when met indicating need for delivery of an anti-arrhythmia therapy, at least said second one or said rules when met indicating that anti-arrhythmia therapy should not be delivered;

analyzing means for determining which of said first and second rules are met, said analyzing means comprising means for determining whether sensed depolarizations continue to meet the criteria for a rule that is met over a sequence of said sensed depolarizations and means responsive to said sensed depolarizations continuing to meet the criteria for a rule that is met over said sequence sensed depolarizations for determining which of said first and second rules are met, said analyzing means responsive to one of said first and second rules being met for determining thereafter that the rule that is met is no longer met only after a plurality of sensed depolarizations fail to meet one of the criteria of the rule;

means operable when the criteria for both the first and second rules are met for determining the highest priority one of said first and second rules which are met; and

means responsive to a determination that said first of said first and second rules that is met constitutes the highest priority rule met for triggering delivery of an anti-arrhythmia therapy.

4. An anti-arrhythmia device comprising:

means for sensing depolarizations of heart tissue;

means for defining a set of prioritized rules, each of said rules defining one or more criteria based upon characteristics of said sensed depolarizations of heart tissue, each said rule being met when the criteria of said rule are met, said rules defined such that at least a first one and a second one of said rules are capable of being simultaneously met, at least said first one of said rules when met indicating need for delivery of an anti-arrhythmia therapy, at least said second one of said rules when met indicating that anti-arrhythmia therapy should not be delivered;

analyzing means for determining which of said first and second rules are met, said analyzing means comprising means for determining whether sensed depolarizations continue to meet the criteria for a rule that is met over a sequence of said sensed depolarizations and means responsive to said sensed depolarizations continuing to meet the criteria for a rule that is met over said sequence sensed depolarizations for determining which of said first and second rules are met, said analyzing means responsive to one of said first and second rules being met for determining thereafter that the rule that is met is no longer met only after a plurality of sensed depolarizations fail to meet one of the criteria of the rule;

means operable when the criteria for both the first and second rules are met for determining the highest priority one of said rules which are met; and

means responsive to a determination that said second one of said first and second rules that is met constitutes the highest priority rule met for preventing delivery of an anti-arrhythmia therapy.

9. An anti-arrhythmia device comprising:

means for sensing depolarizations of heart tissue;

means for defining a plurality of prioritized rules, each of said rules defining one or more criteria based upon characteristics of said sensed depolarizations of heart tissue, each said rule being met when the criteria of said rule are met, said rules defined such that at least a first one and a second one of said rules are capable of being simultaneously met, at least said first one of said rules when met indicating need for delivery of an anti-arrhythmia therapy, at least said second one or said rules when met indicating that anti-arrhythmia therapy should not be delivered;

means for analyzing said characteristics of said sensed depolarizations to determine which of said first and second rules are met, said analyzing means comprising means responsive to any one of said first and second rules being met for determining thereafter that the rule that is met is no longer met only after a plurality of sensed depolarizations fail to meet one of the criteria of the rule;

means operable when the criteria for both the first and second rules are met for determining the highest priority one of said first and second rules which are met;

means responsive to a determination that said first one of said first and second rules that is met constitutes the highest priority rule met for triggering delivery of an anti-arrhythmia therapy;

means responsive to a determination that said second one of said first and second rules that is met constitutes the highest priority rule met, for preventing delivery of an anti-arrhythmia therapy; and

wherein said analyzing means further comprises means for disabling said second one of said rules in response to delivery of said anti-arrhythmia therapy.

10. An anti-arrhythmia device according to claim 9, wherein:

said sensing means comprises means for sensing depolarizations of two heart chambers; and

wherein said rule defining means comprises means for assigning beat codes to intervals between successive depolarizations of one of said heart chambers based on occurrences of depolarizations of the other of said heart chambers therebetween, means for defining a set of allowed sequences of said beat codes indicative of a heart rhythm and means for defining a beat sequence criterion corresponding to a predetermined number of beat codes successively falling within said allowed sequences; and

wherein said analyzing means comprising means for counting the number of sequential beat codes which fall within said defined set of allowed sequences and for determining that said criterion is met in response to said counted number exceeding said predetermined number; and

wherein said responsive means for delivering an anti-arrhythmia therapy comprises means responsive to a rule within said set of prioritized rules employing said beat sequence criterion being met; and

wherein said analyzing means comprises means for disabling said one of said rules in response to delivery of said anti-arrhythmia therapy.