Method and system for second pass confirmation of an arrhythmic episode

Patent metadata

Field	Value
Publication number	US-12245877-B2
Application number	US-202318502402-A
Country	US
Kind code	B2
Filing date	Nov 6, 2023
Priority date	May 7, 2018
Publication date	Mar 11, 2025
Grant date	Mar 11, 2025

Abstract

Computer implemented methods and systems for detecting noise in cardiac activity are provided. The method and system obtain a far field cardiac activity (CA) data set that includes far field CA signals for a series of beats, overlay a segment of the CA signals with a noise search window, and identify turns in the segment of the CA signals. The method and system determine whether the turns exhibit a turn characteristic that exceed a turn characteristic threshold, declare the segment of the CA signals as a noise segment based on the determining operation, shift the noise search window to a next segment of the CA signal and repeat the identifying, determining and declaring operations; and modify the CA signals based on the declaring the noise segments.

First claim

What is claimed is:

1. A computer implemented method for confirming an arrhythmia episode initially declared by a first detection process based on intervals between consecutive first R waves in a segment of CA signals, the first detection process detecting the first R waves based on a first sensitivity profile;
under control of one or more processors configured with executable instructions, implementing a confirmatory detection process that includes:
1) adjusting a parameter of a second sensitivity profile based on at least one P-wave or R-wave amplitudes occurring in the segment of CA signals;
2) comparing an amplitude of the CA signals, in the segment of CA signals, to the second sensitivity profile to detect a series of confirmatory R waves that includes one or more R waves under sensed by the first detection process; and
3) confirming or rejecting the arrhythmia episode based on consecutive R-R intervals for the series of confirmatory R waves that includes the one or more R waves under sensed by the first detection process.

2. The method of claim 1 , wherein operations at 1), 2), and 3) are performed iteratively in real time while a patient is experiencing the arrhythmia episode, and the adjusting is performed in real time to form an adaptive second sensitivity profile based on at least one of P-wave or R-wave amplitudes.

3. The method of claim 1 , wherein the confirming or rejecting further comprises:
determining intervals between the consecutive R waves for the series of confirmatory R waves in the segment of the CA signals; and
determining whether the intervals between consecutive R waves for the series of confirmatory R waves indicate a brady episode.

4. The method of claim 1 , further comprising detecting one or more P-waves in the segment of the CA signals and rejecting the detection of the arrhythmia episode when a number of P-waves in the CA signals is greater than a threshold.

5. The method of claim 3 , wherein the arrhythmia episode represents an atrial fibrillation (AF) episode, the method further comprising performing P-wave detection to determine whether P-waves are present in the segment of CA and confirming or rejecting the AF episode based on a presence of one or more P waves in the segment of the CA signals.

6. The method of claim 1 , wherein the first detection process includes providing device documented (DD) markers in connection with each of the first R-waves that are detected, and wherein the confirmatory detection process includes providing confirmatory markers in connection with each of the confirmatory R-waves that are detected, the confirming or rejecting based on the DD and confirmatory markers.

7. The method of claim 6 , further comprising determining whether a difference exists between the confirmatory and DD markers, the confirming or rejecting including rejecting the arrhythmia episode when the difference exists between the confirmatory and DD markers.

8. The method of claim 1 , further comprising performing premature ventricular contraction (PVC) detection to determine whether one or more PVC are present in the segment of CA signals, confirming or rejecting the arrhythmia episode based on a presence of one or more PVCs in the segment of the CA signals stored.

9. The method of claim 1 , further comprising comparing a duration between consecutive R-R waves to an asystole threshold and, when the duration exceeds the asystole threshold, the method detecting an asystole episode.

10. The method of claim 1 , further comprising:
sensing cardiac activity (CA) signals utilizing the electrodes on an implantable cardiac monitor (ICM) located remote from the heart;
implementing the first detection process within the ICM to declare the arrhythmia episode; and
storing, in memory of the ICM, a segment of the CA signals occurring prior to an event of interest within the arrhythmia episode.

11. The method of claim 1 , further comprising transmitting the segment of the CA signals to at least one of a local external device or a remote server, wherein at least one of the local external device or remote server performs the operations at 1), 2), and 3).

12. The method of claim 1 , wherein the first detection process is implemented within an implantable cardiac monitor (ICM) located remote from the heart and having electrodes provided on the ICM, the method further comprising determining whether the CA signals exhibit a non-physiologic characteristic indicative of at least one of i) motion artifacts or ii) partial or complete loss of contact between subcutaneous tissue and the electrodes.

13. A system for confirming an arrhythmia episode initially declared by a first detection process based on intervals between consecutive first R waves in a segment of CA signals, the first detection process detecting the first R waves based on a first sensitivity profile, the system comprising:
memory to store specific executable instructions;
one or more processors configured to execute the specific executable instructions to:
1) Adjust a parameter of a second sensitivity profile based on at least one of P-wave or R-wave amplitudes occurring in the segment of CA signals;

2) Compare an amplitude of the CA signals, in the segment of CA signals, to the second sensitivity profile to detect a series of confirmatory R waves that includes one or more R waves under sensed by the first detection process; and
3) Confirm or reject the arrhythmia episode based on consecutive R-R intervals for the series of confirmatory R waves that includes the one or more R waves under sensed by the first detection process.

14. The system of claim 13 , wherein the one or more processors are configured to iteratively perform the operations at 1), 2), and 3) in real time while a patient is experiencing the arrhythmia episode, and the adjusting is performed in real time to form an adaptive second sensitivity profile based on at least one of P-wave or R-wave amplitudes.

15. The system of claim 13 , wherein the one or more processors are further configured to perform the confirming or rejecting by:
determining intervals between consecutive R waves for the series of confirmatory R waves in the segment of the CA signals; and
determining whether the intervals between consecutive R waves for the series of confirmatory R waves indicate a brady episode.

16. The system of claim 15 , wherein the one or more processors are further configured to detect one or more P-waves in the segment of the CA signals and reject the detection of an AF episode when a number of P-waves in the CA signals is greater than a threshold.

17. The system of claim 15 , wherein the arrhythmia episode represents an atrial fibrillation (AF) episode, the one or more processors are further configured to perform P-wave detection to determine whether P waves are present in the segment of CA signals and confirm or reject the AF episode based on a presence of one or more P-waves in the segment of the CA signals.

18. The system of claim 13 , wherein the one or more processors are further configured, when rejecting the arrhythmia episode, to classify the segment of the CA signals to represent a false positive.

19. The system of claim 13 , further comprising an implantable cardiac monitor (ICM) configured to be located remote from the heart, the ICM including electrodes configured to sense the CA signals, the ICM including one or more processors that, when executing program instructions, are configured to implement the first detection process to declare the arrhythmia episode and store, in memory of the ICM,

Assignees

• Pacesetter Inc

Inventors

• Gill Jong
• Qu Fujian
• Malhotra Neha
• Rosenberg Stuart
• Bornzin Gene A
• Dawoud Fady

Classifications

• A61B5/361

  Detecting fibrillation · CPC title

• A61B5/352

  Detecting R peaks, e.g. for synchronising diagnostic apparatus; Estimating R-R interval · CPC title

• A61B5/686

  Permanently implanted devices, e.g. pacemakers, other stimulators, biochips (A61B5/6861 takes precedence) · CPC title

• A61B5/7217 Primary

  of noise originating from a therapeutic or surgical apparatus, e.g. from a pacemaker · CPC title