Method and system to detect P-waves in cardiac arrhythmic patterns

Patent metadata

Field	Value
Publication number	US-11883178-B2
Application number	US-202217675345-A
Country	US
Kind code	B2
Filing date	Feb 18, 2022
Priority date	Aug 12, 2020
Publication date	Jan 30, 2024
Grant date	Jan 30, 2024

Abstract

A computer implemented method for detecting arrhythmias in cardiac activity including obtaining far field cardiac activity (CA) signals for a series of beats. For at least a portion of the beats, the one or more processors perform, on a beat by beat basis: a) identifying first and second feature of interests (FOI) from a segment of the CA signal that corresponds to a current beat; and b) classifying the current beat into one of first and second groups. The method also includes designating one of the first and second groups to be a primary group based on a relation between the first and second groups, and for the beats in the primary group, selecting one of the first and second FOIs as the R-wave FOI. The method also includes rejecting an arrhythmia detection based on the P-waves detected.

First claim

What is claimed is:

1. A computer implemented method for detecting arrhythmias in cardiac activity, comprising:
under control of one or more processors configured with specific executable instructions,
obtaining far field cardiac activity (CA) signals for one or more beats;
applying a detection process, to the CA signals, to obtain a device marker;
identifying a first feature of interest (FOI) within an analysis window of a segment of the CA signal;
calculating a difference between the first FOI and the device marker;
adjusting a feature detection window with respect to the CA signals based on the difference;
detecting a second FOI in the feature detection window over the CA signals; and
rejecting an arrhythmia detection based on the second FOI detected.

2. The method of claim 1 , wherein the detection process is an R-wave detection process, the device marker is a device R-wave marker, and the first FOI is an R-wave FOI.

3. The method of claim 2 , wherein the feature detection window is a P-wave detection window, the second FOI is a P-wave and the method rejects the arrhythmia detection based on the P-wave detected.

4. The method of claim 3 , wherein the analysis window positioned, relative to the CA signals, based on the R-wave marker.

5. The method of claim 3 , wherein the P-wave detection window is originally positioned, with respect to the CA signals, based on a location of the device R-wave marker, the adjusting operation including adjusting one or more boundaries of the P-wave detection window, with respect to the CA signals, based on the difference.

6. The method of claim 3 , wherein the difference is calculated in a beat-by-beat manner.

7. The method of claim 6 , further comprising determining a median peak time for the P-waves detected; and determining a peak displacement between a peak time of each of the P-waves detected and the determined median peak time.

8. The method of claim 3 , further comprising calculating a moving combination for the CA signals to form a composite CA signal, the moving combination configured to at least partially remove non-noise artifact displacement (NAD) due to a physiologic condition, the identifying, classifying, adjusting and detecting based on the composite CA signals.

9. The method of claim 8 , wherein the moving combination is configured to at least partially remove a notch in the CA signals, representing the NAD.

10. The method of claim 3 , further comprising identifying the beats that have outlier P-waves, the outlier P-waves having peak to peak amplitudes that are not within a pattern of a distribution of P-wave peak to peak amplitudes for at least a portion of the beats.

11. The method of claim 3 , further comprising repeating the obtaining, identifying, calculating, adjusting, and detecting for multiple beats to detect multiple P-waves, and shifting a peak of a first P-wave of the multiple P-waves to align with a median peak of the multiple P-waves detected.

12. A system for detecting arrhythmias in cardiac activity, comprising:
memory to store specific executable instructions;
one or more processors configured to execute the specific executable instructions to:
obtain far field cardiac activity (CA) signals for one or more beats;
apply a detection process, to the CA signals, to obtain a device marker;
identify a first feature of interest (FOI) within an analysis window of a segment of the CA signal;
calculate a difference between the first FOI and the device marker;
adjust a feature detection window with respect to the CA signals based on the difference;
detect a second FOI in the feature detection window over the CA signals; and
reject an arrhythmia detection based on the second FOI detected.

13. The system of claim 12 , wherein the detection process is an R-wave detection process, the device marker is a device R-wave marker, and the first FOI is an R-wave FOI.

14. The system of claim 13 , wherein the feature detection window is a P-wave detection window, the second FOI is a P-wave and the one or more processors is further configured to reject the arrhythmia detection based on the P-wave detected.

15. The system of claim 14 , wherein the one or more processors are further configured to originally position the P-wave detection window, with respect to the CA signals, based on a location of the device R-wave marker, and to adjust one or more boundaries of the P-wave detection window, with respect to the CA signals, based on the difference.

16. The system of claim 14 , wherein the one or more processors are further configured to calculate the difference in a beat-by-beat manner for multiple beats.

17. The system of claim 16 , wherein the one or more processors are further configured to determine a median peak time for the P-waves detected; and determine a peak displacement between a peak time of each of the P-waves detected and the determined median peak time.

18. The system of claim 17 , wherein the one or more processors are further configured to determine when the peak displacement between the peak time of each of the P-waves detected exceeds a threshold displacement.

19. The system of claim 16 , wherein the one or more processors are further configured to identifying the beats that have outlier P-waves, the outlier P-waves having peak to peak amplitudes that are not within a pattern of a distribution of P-wave peak to peak amplitudes for at least a portion of the beats.

20. The system of claim 12 , wherein the one or more processors are further configured to execute the specific executable instructions to position the analysis window, relative to the CA signals, based on the device marker.

Assignees

• Pacesetter Inc

Inventors

• Qu Fujian
• Badie Nima
• Gill Jong

Classifications

• A61B5/361 Primary

  Detecting fibrillation · CPC title

• A61B5/316

  Modalities, i.e. specific diagnostic methods · CPC title

• A61B5/35

  by template matching · CPC title

• A61B5/7264

  Classification of physiological signals or data, e.g. using neural networks, statistical classifiers, expert systems or fuzzy systems · CPC title

• A61B5/363

  Detecting tachycardia or bradycardia · CPC title