Method and system to characterize motion data based on neighboring map points

• US 9,364,170 B2
• Filed: 05/05/2014
• Issued: 06/14/2016
• Est. Priority Date: 05/05/2014
• Status: Active Grant

• Current Assignee: Pacesetter Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Pacesetter Incorporated (Abbott Laboratories Incorporated)
• Inventors: Nabutovsky, Yelena, Razavi, Hoda
• Primary Examiner(s): Gedeon, Brian T
• Assistant Examiner(s): Tejani, Ankit D
• Application Number:
  US14/270,181
• Publication Number:
  US 20150313511A1
• Time in Patent Office: 771 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: A61B 5/061 Determining position of a probe within the body employing means separate from the probe, e.g. sensing internal probe position employing impedance electrodes on the surface of the body A61B1/00158 takes precedence
• CPC Class Codes: A61B 5/062 using magnetic field
• CPC Class Codes: A61B 5/1102 Ballistocardiography
• CPC Class Codes: A61B 5/1107 Measuring contraction of parts of the body, e.g. organ, muscle apparatus for measuring work or force in general G01L
• CPC Class Codes: A61B 5/1126 using a particular sensing technique
• CPC Class Codes: A61B 5/287 Holders for multiple electrodes, e.g. electrode catheters for electrophysiological study [EPS]
• CPC Class Codes: A61B 5/6869 Heart
• CPC Class Codes: A61B 5/7278 Artificial waveform generation or derivation, e.g. synthesising signals from measured signals A61B5/327 takes precedence
• CPC Class Codes: A61B 5/7289 Retrospective gating, i.e. associating measured signals or images with a physiological event after the actual measurement or image acquisition, e.g. by simultaneously recording an additional physiological signal during the measurement or image acquisition

Abstract

A method and system are provided for characterizing motion data. The method and system obtain point specific (PS) motion data for a plurality of map points. The PS motion data indicates an amount of motion that occurred at the corresponding map point on a wall of the heart during at least one cardiac cycle. The method and system, calculate mechanical activation times (MAT) for the map points, identifying a group of neighbor map points for a current map point, and modifying the MAT corresponding to the current map point based on the MATs corresponding to at least a portion of the group of neighboring map points. Further, the method and system repeat the identifying and modifying operations for at least a subset of the map points.

Claims

1. A method for characterizing motion data collected by a cardiovascular navigation system, the method comprising:

obtaining point specific (PS) motion data for a plurality of map points, wherein the PS motion data indicates an amount of motion that occurred at the corresponding map point on a wall of the heart during at least one cardiac cycle;

calculating mechanical activation times (MAT) for the map points based on the PS motion data;

identifying a group of neighboring map points for a current map point;

modifying the MAT corresponding to the current map point based on the MATs corresponding to at least a portion of the group of neighboring map points; and

repeating the identifying and modifying operations for at least a subset of the map points.

2. The method of claim 1, wherein the calculating operation comprises calculating a three-dimension (3D) physical distance between pairs of map points.

3. The method of claim 1, wherein the PS motion data defines a motion waveform at the corresponding map point, where the motion waveform represents at least one of displacement, strain, or strain rate over a select period of time, the calculating operation calculating the MATs based on the motion waveforms.

4. The method of claim 3, further comprising assigning clarity scores to each of the motion waveforms based on a distinctiveness of a feature of interest within the motion waveforms used to determine the MATs, the clarity scores representing confidence levels in the corresponding MATs.

5. The method of claim 4, wherein the assigning operation assigns the clarity scores based on at least one of a number of peaks, flatness, and a number of zero slopes in the motion waveform.

6. The method of claim 1, further comprising assigning clarity scores to the MATs associated with the map points, wherein the modifying operation determines whether to modify the MAT based on whether the corresponding clarity scores are above a select level.

7. The method of claim 6, wherein, when a first map point has a corresponding clarity above a select first level indicative of a clear motion waveform morphology, a MAT associated with the first map point is not modified based on MATs for the corresponding neighboring map points.

8. The method of claim 6, wherein, when a second map point has a corresponding clarity below a select second level indicative of an unclear motion waveform morphology, a MAT associated with the second map point is modified based on MATs for the corresponding neighboring map points that have higher clarity relative to the clarity of the second map point.

9. The method of claim 6, wherein, when a third map point has a corresponding clarity below a select third level indicative of an unclear motion waveform morphology, a MAT associated with the third map point is discarded and excluded from analysis.

10. The method of claim 1, wherein the identifying operation excludes from the group of the neighboring map points any map points that are further than a predetermined radius away from the current map point.

11. The method of claim 1, further comprising calculating extents of motion (EMs) for the corresponding map points.

12. The method of claim 11, further comprising assigning clarity scores to the MATs and the EMs associated with the corresponding map points.

13. A system for characterizing motion data collected by cardiovascular navigation system (CNS), the system comprising:

a plurality of physiological sensors configured to be positioned adjacent to a plurality of map points on a heart, wherein the physiological sensors acquire point specific (PS) motion data at the corresponding map points, the PS motion data indicates an amount of motion that occurred at the map points on a wall of the heart during at least one cardiac cycle;

a PS motion data analysis circuit module configured to determine, from the PS motion data and from the map points, a mechanical activation time (MAT); and

a MAT modification circuit module configured to modify the MAT of a selected map point based on the MATs corresponding to at least a subset of the map points.

14. The system of claim 13, wherein the PS motion data defines a motion waveform at the corresponding map point, where the motion waveform represents at least one of a displacement, strain, or strain rate over a select period of time, the calculating operation calculating the MATs based on the motion waveforms.

15. The system of claim 14, further comprising a MAT analysis circuit configured to assign a clarity score to the motion waveform based on a distinctiveness of a feature of interest within the motion waveforms used to determine the MATs and at least one of a number of peaks, flatness, and a number of zero slopes in the motion waveform.

16. The system of claim 13, further comprising a MAT analysis circuit configured to assign a clarity score to the calculated MATs, wherein the MAT modification circuit module is configured to modify the MAT of a selected map point based on whether the corresponding clarity scores are above a select level.

17. The system of claim 13, wherein the subset of the map points are within a predetermined radius of the selected map point.

18. The system of claim 17, wherein the subset of the map points and the select map point does not include map points having a corresponding clarity score below a select third level indicative of an unclear motion waveform morphology.

19. The system of claim 17, wherein the select map point has a corresponding clarity score below a select second level indicative of an unclear motion waveform morphology, the subset of the map points have higher clarity scores relative to the select map point.

20. The system of claim 17, wherein the select map point does not have a corresponding clarity score above a select first level indicative of a clear motion waveform morphology.