Robust Rate Calculation in an Implantable Cardiac Stimulus or Monitoring Device
First Claim
1. A method of cardiac signal analysis in an implantable cardiac system for monitoring or treating a patient'"'"'s heart, the implantable cardiac system including at least a plurality of implantable electrodes, the method comprising:
- sensing a signal using the implantable electrodes;
detecting a series of events in the sensed signal, the series of events separated by intervals, to obtain a set of intervals;
within the set of intervals, selecting a longest interval and generating a limited set of intervals that excludes the longest interval; and
estimating a cardiac rate of the patient using the intervals in the limited set of intervals.
1 Assignment
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Accused Products
Abstract
Devices and methods for analyzing cardiac signal data. An illustrative method includes identifying a plurality of detected events and measuring intervals between the detected events for use in rate estimation. In the illustrative embodiment, a set of intervals is used to make the rate estimation by first discarding selected intervals from the set. The remaining intervals are then used to calculate an estimated interval, for example by averaging the remaining intervals.
18 Citations
23 Claims
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1. A method of cardiac signal analysis in an implantable cardiac system for monitoring or treating a patient'"'"'s heart, the implantable cardiac system including at least a plurality of implantable electrodes, the method comprising:
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sensing a signal using the implantable electrodes; detecting a series of events in the sensed signal, the series of events separated by intervals, to obtain a set of intervals; within the set of intervals, selecting a longest interval and generating a limited set of intervals that excludes the longest interval; and estimating a cardiac rate of the patient using the intervals in the limited set of intervals. - View Dependent Claims (2, 3, 4, 5)
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6. A method of cardiac signal analysis in an implantable cardiac system for monitoring or treating a patient'"'"'s heart, the implantable cardiac system including at least a plurality of implantable electrodes, the method comprising:
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sensing a signal using the implantable electrodes; detecting events in the sensed signal, the detected events separated by intervals; at a first time, using a first method to estimate a heart rate for the patient using information related to the detected events; comparing the heart rate for the patient estimated using the first method to a rate threshold and determining that the threshold has been crossed; at a second time after determining that the rate threshold has been crossed, using a second, different method to estimate the heart rate for the patient. - View Dependent Claims (7, 8)
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9. A method of cardiac signal analysis in an implantable cardiac system for monitoring or treating a patient'"'"'s heart, the implantable cardiac system including at least a plurality of implantable electrodes, the method comprising:
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sensing a signal using the implantable electrodes; detecting a series of events in the sensed signal, the series of events separated by intervals, to obtain a set of intervals; within the set of intervals, selecting a shortest interval and generating a limited set of intervals that excludes the shortest interval; and estimating a cardiac rate of the patient using the intervals in the limited set of intervals. - View Dependent Claims (10, 11, 12, 13)
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14. A method of cardiac signal analysis in an implantable cardiac system for monitoring or treating a patient'"'"'s heart, the implantable cardiac system including at least a plurality of implantable electrodes, the method comprising:
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sensing a signal using the implantable electrodes; detecting a series of events in the sensed signals, the series of events separated by intervals, to obtain a set of intervals; performing a noise detection analysis on the series of events to identify any suspect events and labeling an interval before and an interval after any suspect event as a suspect interval; performing an overdetection analysis on the series of events to identify any overdetected events and combining an interval before and an interval after each overdetected event into a single combined interval; performing a first rate calculation by taking a first subset of the set of intervals and reducing the first subset by excluding at least one shortest interval and at least one longest interval from the first subset to generate a reduced first subset and then calculating a first rate based on the reduced first subset; performing a second rate calculation by taking a second subset consisting of a selected N intervals from the set of intervals where the N intervals are selected by excluding any suspect intervals and then taking N combined intervals and intervals that have not been combined from those that remain after excluding the suspect intervals, and calculating a second rate based on the second subset; and performing rhythm analysis using either the first rate or the second rate.
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15. A method of cardiac signal analysis in an implantable cardiac system for monitoring or treating a patient'"'"'s heart, the implantable cardiac system including at least a plurality of implantable electrodes, the method comprising:
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sensing a signal using the implantable electrodes; detecting a series of events in the sensed signals, the series of events separated by intervals, to obtain a set of intervals; selecting a first set of intervals for a first rate calculation; performing a first rate calculation by obtaining a mean and error measure for the first set of intervals and using the mean less the error measure to estimate cardiac rate for the patient. - View Dependent Claims (16, 17, 18)
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19. An implantable cardiac system for monitoring or treating a patient'"'"'s heart, the implantable cardiac system including at least a plurality of implantable electrodes and a canister housing operational circuitry, the operational circuitry configured to perform a method of cardiac signal analysis:
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sensing a signal using the implantable electrodes; detecting a series of events in the sensed signal, the series of events separated by intervals, to obtain a set of intervals; within the set of intervals, selecting a longest interval and generating a limited set of intervals that excludes the longest interval; and estimating a cardiac rate of the patient using the intervals in the limited set of intervals. - View Dependent Claims (20, 21, 22, 23)
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Specification