Multi-electrode mapping system

• US 9,398,862 B2
• Filed: 04/23/2009
• Issued: 07/26/2016
• Est. Priority Date: 04/23/2009
• Status: Active Grant

• Current Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Original Assignee: Rhythmia Medical, Inc. (Boston Scientific Corporation)
• Inventors: Harlev, Doron, Badics, Zsolt
• Primary Examiner(s): Patel, Niketa
• Assistant Examiner(s): Hankins, Lindsey G
• Application Number:
  US12/428,838
• Publication Number:
  US 20100274150A1
• Time in Patent Office: 2,651 Days
• Field of Search: 600508-528, 600/372, 607/9, 607/27, 607/28
• US Class Current: 1/1
• CPC Class Codes: A61B 5/062 using magnetic field
• CPC Class Codes: A61B 5/24 Detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof
• CPC Class Codes: A61B 5/287 Holders for multiple electrodes, e.g. electrode catheters for electrophysiological study [EPS]
• CPC Class Codes: A61B 5/316 Modalities, i.e. specific diagnostic methods
• CPC Class Codes: A61B 5/339 Displays specially adapted therefor
• CPC Class Codes: A61B 5/349 Detecting specific parameters of the electrocardiograph cycle
• CPC Class Codes: A61B 5/6852 Catheters
• CPC Class Codes: A61N 1/3702 Physiological parameters A61N1/365 takes precedence; evoked response A61N1/371

Abstract

In some aspects, a method includes measuring unipolar signals at one or more electrodes in response to electrical activity in a heart cavity. The method also includes determining, based at least in part on Laplace'"'"'s equation, bipolar physiological information at multiple locations of an surface based on the measured unipolar signals and positions of the one or more electrodes with respect to the surface.

Claims

1. A method comprising:

measuring physiological signals in response to electrical activity in a heart cavity having a surface, the physiological signals comprising unipolar potential signals and measuring each of the physiological signals comprising measuring a potential between a first electrode and a second electrode, the first electrode being located within the heart cavity and the second electrode being located at a distance from the heart cavity such that the electrode is not affected by local tissue activation in a heart cavity;

determining a transformation function that transforms between spatial coordinates of positions of the first electrode in the heart cavity and coordinates of the surface;

determining, based at least in part on Laplace'"'"'s equation, bipolar physiological information at multiple locations of the surface based on the measured unipolar potential signals and the positions of the first electrode with respect to the surface, and based on at least one of subtracting the measured unipolar potential signals from neighboring positions and subtracting, from neighboring positions, surface potentials determined from a unipolar potential inverse engine, the bipolar physiological information comprising current density information; and

displaying an electro-anatomical map (“

EAM”

), the EAM comprising an electro-anatomical depiction of at least a portion of the surface of the heart cavity, the EAM further comprising the determined current density information.

2. The method of claim 1, wherein the first and second electrodes are separated by a distance greater than 10 cm.

3. The method of claim 1, wherein:

the second electrode comprises a plurality of electrodes used to compute a Wilson'"'"'s central terminal measurement; and

measuring the physiological signals comprises measuring a potential between the first electrode and the electrodes used to compute the Wilson'"'"'s central terminal measurement.

4. The method of claim 1, wherein the current density information comprises a normal component of the current density.

5. The method of claim 1, wherein the current density information comprises a magnitude of a current density vector.

6. The method of claim 1, wherein the current density information comprises a magnitude of a tangential component of the current density.

7. The method of claim 1, wherein measuring the physiological signals comprises measuring the physiological signals for multiple different catheter positions in the heart cavity.

8. The method of claim 7, wherein the physiological signals are measured for at least one electrical heart cycle for each catheter position and the determination of the bipolar physiological information at the multiple locations of the surface comprises synchronizing the physiological signals measured at the different catheter positions with one another according to an electrical heart beat cycle.

9. The method of claim 8, wherein the determination of the bipolar physiological information at the multiple locations of the surface further comprises processing the synchronized physiological signals as though they were obtained at one time from all of the positions sampled by the catheter electrodes for the different positions of the catheter in the heart cavity.

10. The method of claim 1, wherein determining the bipolar physiological information comprises applying a transformation function to the measured physiological signals.

11. The method of claim 10, wherein the transformation comprises a forward transformation that relates the bipolar physiological information at the multiple locations to the signals measured.

12. The method of claim 11, wherein applying the transformation function comprises solving directly for current.

13. The method of claim 11, wherein applying the transformation function comprises solving simultaneously for current and potential.

14. The method of claim 13, wherein solving simultaneously for current and potential comprises solving a transformation function which can be expressed as one or more matrices that can be represented by the following equation:

15. The method of claim 10, wherein applying the transformation function comprises calculating a forward transformation for relating the bipolar physiological information at the multiple locations to the signals measured and inverting the forward transformation.

16. The method of claim 15, wherein inverting the forward transformation comprises reformulating an underdetermined matrix inversion by regularization.

17. The method of claim 16, wherein the regularization is based on a physical relationship.

18. The method of claim 17, wherein the physical relationship comprises relationship between current and potential.

19. The method of claim 17, wherein the regularization further comprises limiting the current density magnitude.

20. The method of claim 16, wherein the regularization comprises a volumetric regularization.

21. The method of claim 1, wherein the first electrode comprises multiple spatially distributed electrodes mounted on one or more catheters that are placed inside the heart cavity.

22. The method of claim 21, wherein, during the measurement of the physiological signals, at least some of the electrodes are spaced apart from the surface.

23. The method of claim 21, wherein, during the measurement of the physiological signals, at least some of the electrodes are in contact with the surface.

25. The method of claim 1, wherein the surface comprises one or more of an endocardial surface of the heart and an epicardial surface of the heart.

26. The method of claim 1, wherein the displayed information comprises bipolar electrogram information.

27. The method of claim 1, wherein the displayed information comprises reconstructed bipolar information.

28. The method of claim 1, wherein the displayed information comprises an isocurrent map.

29. The method of claim 1, wherein the bipolar physiological information comprises information generated by post processing of the bipolar physiological information.

30. The method of claim 29, wherein the information generated by the post processing of the bipolar physiological information comprises an amplitude map.

31. The method of claim 29, wherein the information generated by the post processing of the bipolar physiological information comprises a vector isocurrent map.

32. The method of claim 1, wherein:

the second electrode comprises one or more electrodes used to derive a surface potential; and

measuring the physiological signals comprises measuring a potential between the first electrode and the one or more electrodes used to derive the surface potential.

24. The method of 1, wherein the second electrode comprises one or more body-surface electrodes.

33. A method comprising:

measuring electrical potentials between a first electrode located in a heart cavity and a second electrode located outside the heart cavity in response to electrical activity in the heart cavity having a surface;

determining a transformation function that transforms between spatial coordinates of positions of the first electrode in the heart cavity and coordinates of the surface;

determining bipolar information at multiple locations of the surface based on the measured electrical potentials and the positions of the first electrode with respect to the surface, and based on at least one of subtracting the measured electrical potentials from neighboring positions and subtracting, from neighboring positions, surface potentials determined from a unipolar potential inverse engine, the bipolar information comprising a normal component of the current density, a magnitude of a current density vector, or a magnitude of a tangential component of the current density; and

displaying an electro-anatomical map (“

EAM”

), the EAM comprising an electro-anatomical depiction of at least a portion of the surface of the heart cavity, the EAM further comprising the determined bipolar information.

34. The method of claim 33, wherein measuring the electrical potentials comprises measuring the electrical potentials for multiple different catheter positions in the heart cavity having an endocardium surface.

35. The method of claim 33, wherein the electrical potentials are measured for at least one electrical heart cycle for each of multiple catheter positions.

36. The method of claim 35, wherein the determination of the bipolar information at the multiple locations of the surface comprises synchronizing the electrical potentials measured at the different catheter positions with one another according to an electrical heart beat cycle.

37. The method of claim 33, wherein determining the bipolar information comprises applying a transformation function to the measured electrical potentials.

38. The method of claim 37, wherein applying the transformation function comprises solving directly for current.

39. The method of claim 37, wherein applying the transformation function comprises solving simultaneously for current and potential.

40. The method of claim 39, wherein solving simultaneously for current and potential comprises solving a transformation function which can be expressed as one or more matrices.

41. The method of claim 40, wherein the one or more matrices can be represented by the following equation:

42. The method of claim 33, wherein the determining the bipolar information further comprises determining the transformation function by calculating a forward transformation for relating the bipolar information at the multiple locations to the electrical potentials measured and inverting the forward transformation.

43. The method of claim 42, wherein inverting the forward transformation comprises reformulating an underdetermined matrix inversion by regularization.

44. The method of claim 43, wherein the regularization is based on a physical relationship between current and potential.

45. The method of claim 44, wherein the physical relationship can be represented by the following equation:

[K_a,ce][Φ

_ce]=−

[K_ac][V_c].

46. The method of claim 44, wherein the regularization further comprises limiting the current magnitude.

47. The method of claim 43, wherein the regularization comprises a volumetric regularization.

48. The method of claim 33, wherein the surface comprises at least one of an endocardial surface of the heart or an epicardial surface of the heart.

49. The method of claim 33, wherein the bipolar information comprises an isocurrent map that includes current densities.

50. The method of claim 33, wherein the bipolar information comprises a timing map that includes information on time-dependent behavior of the heart'"'"'s electrical activity.