Methods, devices and systems for distinguishing over-sensed R-R intervals from true R-R intervals

1 . A method performed by at least one of a processor or controller of an implantable medical device or system that is configured to transmit, to an external device that is communicatively coupled to a patient care network, data corresponding to one or more arrhythmic episode detected by the implantable medical device or system, the method comprising:

obtaining a list of sensed intervals associated with an the arrhythmic episode detection, wherein each of the sensed intervals has a respective duration;

using a first set of criteria to identify true R-R intervals in the list of sensed intervals, wherein the using the first set of criteria includes

identifying as a true R-R interval, each said sensed interval having a duration that is within a first specified threshold of a sum of the durations of an immediately preceding or an immediately following two intervals in the list of sensed intervals; and

identifying as a true R-R interval, each said sensed interval having a duration that is within a second specified threshold of a mean or median of the durations of the sensed intervals already identified as true R-R intervals, wherein the second specified threshold may or may not be the same as the first specified threshold;

using a second set of criteria to identify false R-R intervals, from those of the sensed intervals not already identified as true R-R intervals using the first set of criteria;

determining whether the arrhythmic episode detection was a false positive detection, based on results of the using the second set of criteria to identify false R-R intervals; and

preventing or limiting transmitting, to the external device that is communicatively coupled to the patient care network, of data corresponding to the arrhythmic episode that is detected by the implantable medical device or system and is thereafter determined by the implantable medical device or system as being a false positive detection.

2 . The method of claim 1 , wherein the second set of criteria, which is used to identify the false R-R intervals, from those of the sensed intervals not already identified as true R-R intervals using the first set of criteria, includes:

using a short interval variability criterion;

using a short-long interval discrepancy criterion; and

using a short interval duration criterion.

3 . The method of claim 2 , for those of the sensed intervals not already identified as true R-R intervals using the first set of criteria, classifying individual sensed intervals as either a short interval or a long interval, and wherein for a said sensed interval classified as a said short interval:

the short interval variability criterion is satisfied when a difference between the duration of the sensed interval and the duration of an immediately preceding sensed interval also classified as a said short interval is within a specified threshold;

the short-long interval discrepancy criterion is satisfied when a difference between the duration of the sensed interval and the duration of an immediately following sensed interval classified as a said long interval is greater than a further specified threshold; and

the short interval duration criterion is satisfied when the duration of the sensed interval is less than another specified threshold.

4 . The method of claim 1 , wherein the obtaining the list of sensed intervals comprises:

obtaining an electrogram (EGM) or electrocardiogram (ECG) segment corresponding to a period of time preceding and leading up to the arrhythmic episode detection

identifying potential R-waves within the EGM or ECG segment; and

determining intervals between consecutive ones of the potential R-waves to thereby produce the list of sensed intervals.

5 . The method of claim 1 , wherein the arrhythmic episode detection comprises an atrial fibrillation (AF) detection.

6 . The method of claim 1 , wherein the obtaining the list of sensed intervals comprises:

obtaining an electrogram (EGM) segment associated with the arrhythmic episode detection;

identifying potential R-waves within the EGM segment; and

determining intervals between consecutive ones of the potential R-waves to thereby produce the list of sensed intervals.

7 . The method of claim 1 , wherein the implantable medical device or system comprises one of the following:

an insertable cardiac monitor (ICM);

a cardiac pacemaker to which one or more leads are attached;

a leadless cardiac pacemaker (LCP); or

an implantable cardioverter defibrillator (ICD).

8 . The method of claim 1 , wherein the implantable medical device or system is configured to selectively deliver therapy, and the method further comprises inhibiting delivery of the therapy in response to determining the arrhythmic episode detection was a false positive detection.

9 . An implantable medical device or system, comprising:

one or more electrodes;

a sensing circuitry coupled to the one or more electrodes and configured to obtain a signal indicative of electrical activity of a patient's heart; and

at least one of a processor or controller configured to:

detect an arrhythmic episode based on the signal indicative of electrical activity of the patient's heart;

obtain a list of sensed intervals associated with the arrhythmic episode detection, wherein each of the sensed intervals has a respective duration;

use a first set of criteria to identify true R-R intervals in the list of sensed intervals, wherein use of the first set of criteria includes

identify as a true R-R interval, each said sensed interval having a duration that is within a first specified threshold of a sum of the durations of an immediately preceding or an immediately following two intervals in the list of sensed intervals; and

identify as a true R-R interval, each said sensed interval having a duration that is within a second specified threshold of a mean or median of the durations of the sensed intervals already identified as true R-R intervals, wherein the second specified threshold may or may not be the same as the first specified threshold;

use a second set of criteria to identify false R-R intervals, from those of the sensed intervals not already identified as true R-R intervals using the first set of criteria; and

determine whether the arrhythmic episode detection was a false positive detection, based on results of the using the second set of criteria to identify false R-R intervals;

wherein the implantable medical device is configured to selectively deliver therapy; and

wherein the at least one of the processor or controller is further configured to inhibit delivery of the therapy in response to a determination that the arrhythmic episode detection was a false positive detection.

10 . The implantable medical device or system of claim 9 , wherein the second set of criteria, which are used to identify false R-R intervals, from those of the sensed intervals not already identified as true R-R intervals using the first set of criteria, includes:

a short interval variability criterion;

a short-long interval discrepancy criterion; and

a short interval duration criterion.

11 . The implantable medical device or system of claim 10 , for those of the sensed intervals not already identified as true R-R intervals using the first set of criteria, the at least one of the processor or controller is configured to classify individual sensed intervals as either a short interval or a long interval, and wherein for a said sensed interval classified as a said short interval the at least one of the processor or controller is configured to determine that:

the short interval variability criterion is satisfied when a difference between the duration of the sensed interval and the duration of an immediately preceding sensed interval also classified as a said short interval is within a specified threshold;

the short-long interval discrepancy criterion is satisfied when a difference between the duration of the sensed interval and the duration of an immediately following sensed interval classified as a said long interval is greater than a further specified threshold; and

the short interval duration criterion is satisfied when the duration of the sensed interval is less than another specified threshold.

12 . The implantable medical device or system of claim 9 , wherein:

the signal indicative of electrical activity of the patient's heart, that the sensing circuitry is configured to obtain, comprises an electrogram (EGM) or electrocardiogram (ECG) segment corresponding to a period of time preceding and leading up to the arrhythmic episode detection; and

the at least one of the processor or controller is configured to identify potential R-waves within the EGM or ECG segment, and determine intervals between consecutive ones of the potential R-waves to thereby produce the list of sensed intervals.

13 . The implantable medical device or system of claim 9 , wherein the arrhythmic episode detection comprises an atrial fibrillation (AF) detection.

14 . The implantable medical device or system of claim 9 , further comprising:

a transceiver configured to wireless communicate with an external device that is communicatively coupled to a patient care network;

wherein the at least one of the processor or controller is further configured to prevent or limit transmission by the transceiver, to the external device that is communicatively coupled to the patient care network, of data corresponding to the arrhythmic episode that is detected by the implantable medical device or system and is thereafter determined to be a false positive detection.

15 . The implantable medical device or system of claim 9 , wherein:

the signal indicative of electrical activity of the patient's heart, that the sensing circuitry is configured to sense, comprises an electrogram (EGM) segment; and

the at least one of the processor or controller is configured to identify potential R-waves within the EGM segment, and determine intervals between consecutive ones of the potential R-waves, to thereby produce the list of sensed intervals.

16 . The implantable medical device or system of claim 9 , wherein the implantable medical device or system comprises one of the following:

an insertable cardiac monitor (ICM);

a cardiac pacemaker to which one or more leads are attached;

a leadless cardiac pacemaker (LCP); or

an implantable cardioverter defibrillator (ICD).

17 . An insertable cardiac monitor (ICM), comprising:

one or more electrodes;

a sensing circuitry coupled to the one or more electrodes and configured to obtain a signal indicative of electrical activity of a patient's heart;

a transceiver configured to wireless communicate with an external device that is communicatively coupled to a patient care network; and

at least one of a processor or controller configured to:

detect an arrhythmic episode based on the signal indicative of electrical activity of the patient's heart;

obtain a list of sensed intervals associated with the arrhythmic episode detection, wherein each of the sensed intervals has a respective duration;

use a first set of criteria to identify true R-R intervals in the list of sensed intervals, wherein use of the first set of criteria includes

identify as a true R-R interval, each said sensed interval having a duration that is within a first specified threshold of a sum of the durations of an immediately preceding or an immediately following two intervals in the list of sensed intervals; and

identify as a true R-R interval, each said sensed interval having a duration that is within a second specified threshold of a mean or median of the durations of the sensed intervals already identified as true R-R intervals, wherein the second specified threshold may or may not be the same as the first specified threshold;

use a second set of criteria to identify false R-R intervals, from those of the sensed intervals not already identified as true R-R intervals using the first set of criteria; and

determine that the arrhythmic episode detection was a false positive detection, based on results of the using the second set of criteria to identify false R-R intervals; and

prevent transmission by the transceiver, to the external device that is communicatively coupled to the patient care network, of data corresponding to the arrhythmic episode detection that is determined to be the false positive detection.

18 . The ICM of claim 17 , wherein the second set of criteria, which are used to identify false R-R intervals, from those of the sensed intervals not already identified as true R-R intervals using the first set of criteria, includes:

a short interval variability criterion;

a short-long interval discrepancy criterion; and

a short interval duration criterion.

19 . The ICM of claim 18 , for those of the sensed intervals not already identified as true R-R intervals using the first set of criteria, the at least one of the processor or controller is configured to classify individual sensed intervals as either a short interval or a long interval, and wherein for a said sensed interval classified as a said short interval the at least one of the processor or controller is configured to determine that:

the short interval variability criterion is satisfied when a difference between the duration of the sensed interval and the duration of an immediately preceding sensed interval also classified as a said short interval is within a specified threshold;

the short-long interval discrepancy criterion is satisfied when a difference between the duration of the sensed interval and the duration of an immediately following sensed interval classified as a said long interval is greater than a further specified threshold; and

the short interval duration criterion is satisfied when the duration of the sensed interval is less than another specified threshold.

20 . The ICM of claim 17 , wherein:

the signal indicative of electrical activity of the patient's heart, that the sensing circuitry is configured to sense, comprises an electrogram (EGM) segment; and

the at least one of the processor or controller is configured to identify potential R-waves within the EGM segment, and determine intervals between consecutive ones of the potential R-waves, to thereby produce the list of sensed intervals.

21 . The ICM of claim 17 , wherein the arrhythmic episode detection comprises an atrial fibrillation (AF) detection.