Systems and methods for improved atrial fibrillation (AF) monitoring
First Claim
1. A method for use with a system that monitors for atrial fibrillation (AF) based on RR interval variability as measured from an electrocardiogram (ECG) signal, the method comprising:
- (a) obtaining a patient specific activity threshold;
(b1) monitoring patient activity with an activity sensor not based on a cardiac electrical signal;
(b2) monitoring for AF based on RR interval variability in said ECG signal;
(c) determining, based on the monitored patient activity and the patient specific activity threshold, when it is likely that AF monitoring based on RR interval variability is adversely affected by patient activity, wherein step (c) includes;
(c.1) determining activity correlation values based on both the monitored patient activity and heart rate reserve values corresponding to the monitored patient activity; and
(c.2) determining that it is likely that AF monitoring based on RR interval variability is adversely affected, when the activity correlation values exceed the patient specific activity threshold; and
(d) modifying whether and/or how AF monitoring is performed, when it has been determined that it is likely that AF monitoring based on RR interval variability is adversely affected by patient activity.
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Accused Products
Abstract
Methods and systems described herein are especially useful wherein monitoring for atrial fibrillation (AF) is based on RR interval variability as measured from an electrocardiogram (ECG) signal. An activity threshold, which can be patient specific, is obtained. Patient activity is monitored. Based on the monitored patient activity and the activity threshold, there is a determination of when it is likely that AF monitoring based on RR interval variability is adversely affected by patient activity. When it has been determined that it is likely that AF monitoring based on RR interval variability is adversely affected by patient activity, whether and/or how AF monitoring is performed is modified.
83 Citations
21 Claims
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1. A method for use with a system that monitors for atrial fibrillation (AF) based on RR interval variability as measured from an electrocardiogram (ECG) signal, the method comprising:
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(a) obtaining a patient specific activity threshold; (b1) monitoring patient activity with an activity sensor not based on a cardiac electrical signal; (b2) monitoring for AF based on RR interval variability in said ECG signal; (c) determining, based on the monitored patient activity and the patient specific activity threshold, when it is likely that AF monitoring based on RR interval variability is adversely affected by patient activity, wherein step (c) includes; (c.1) determining activity correlation values based on both the monitored patient activity and heart rate reserve values corresponding to the monitored patient activity; and (c.2) determining that it is likely that AF monitoring based on RR interval variability is adversely affected, when the activity correlation values exceed the patient specific activity threshold; and (d) modifying whether and/or how AF monitoring is performed, when it has been determined that it is likely that AF monitoring based on RR interval variability is adversely affected by patient activity. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A system, comprising:
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an atrial fibrillation (AF) monitor configured to monitor for AF based on RR interval variability as measured from an ECG signal; memory to store information about detected episodes of AF; at least one activity sensor configured to monitor patient activity without using a cardiac electrical signal; at least one processor configured to determine; activity correlation values based on both the monitored patient activity and heart rate reserve values corresponding to the monitored patient activity; and that it is likely that AF monitoring based on RR interval variability is adversely affected, when the activity correlation values exceed the patient specific activity threshold; and wherein whether to or how to monitor for AF is modified, when the at least one processor determines that it is likely that AF monitoring based on RR interval variability is adversely affected by patient activity. - View Dependent Claims (15, 16, 17, 18)
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19. A method for use with a system that monitors for atrial fibrillation (AF) based on RR interval variability as measured from an electrocardiogram (ECG) signal, the method comprising:
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(a) obtaining a patient specific activity threshold; (b1) monitoring patient activity with an activity sensor not based on a cardiac electrical signal; (b2) monitoring for AF based on RR interval variability in said ECG signal; (c) determining, based on both the monitored patient activity and the patient specific activity threshold, when it is likely that AF monitoring based on RR interval variability is adversely affected by patient activity, wherein step (c) includes; (c.1) determining activity correlation values based on both the monitored patient activity and corresponding heart rate data; and (c.2) determining that it is likely that AF monitoring based on RR interval variability is adversely affected, when the activity correlation values exceed the patient specific activity threshold; (d) modifying whether and/or how AF monitoring is performed, when it has been determined that it is likely that AF monitoring based on RR interval variability is adversely affected by patient activity, wherein step (d) comprises; storing information about detected episodes of AF along with an indication that the detected episodes of AF were detected during elevated patient activity; analyzing the stored information about episodes of AF that were detected during elevated patient activity, in order to determine which detected episodes were actually AF episodes and which detected episodes were detected due to patient activity; and adjusting a variability threshold, used to detected episodes of AF, based on results of the analyzing. - View Dependent Claims (20, 21)
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Specification