Tissue Lesion Evaluation

• US 20090299365A1
• Filed: 05/13/2009
• Published: 12/03/2009
• Est. Priority Date: 05/13/2008
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Francischelli, David, Stewart, Mark, Hong, Jinback, Ahlberg, Sarah
• Granted Patent: US 8,821,488 B2
• Time in Patent Office: Days
• US Class Current: 606/41
• CPC Class Codes: A61B 18/1445 at the distal end of a shaft, e.g. forceps or scissors at the end of a rigid rod
• CPC Class Codes: A61B 2018/00029 open
• CPC Class Codes: A61B 2018/00065 porous
• CPC Class Codes: A61B 2018/00113 with foam
• CPC Class Codes: A61B 2018/0016 Energy applicators arranged in a two- or three dimensional array
• CPC Class Codes: A61B 2018/00357 Endocardium
• CPC Class Codes: A61B 2018/00363 Epicardium
• CPC Class Codes: A61B 2018/00577 Ablation
• CPC Class Codes: A61B 2018/00839 Bioelectrical parameters, e.g. ECG, EEG
• CPC Class Codes: A61B 2018/1472 for use with liquid electrolyte, e.g. virtual electrodes
• CPC Class Codes: A61B 2090/064 for measuring force, pressure or mechanical tension
• CPC Class Codes: A61B 2218/002 Irrigation

Abstract

Device, system and method for ablating tissue of a heart of a patient. The tissue is clamped between a pair of opposing jaws. A portion of the tissue is ablated at a first generally linear position on the tissue by applying ablative energy to two of a plurality of elongate electrodes, each of the two of the plurality of elongate electrodes being coupled in opposing relationship to each other and the pair of opposing jaws, respectively. An effectiveness of the ablation is sensed at a second generally linear position on the tissue with at least one of the plurality of elongate electrodes positioned on one of the pair of opposing jaws. The second linear position on the tissue is laterally distal to the first linear position on the tissue with respect to the atrium of the heart.

Claims

1. A method for ablating tissue of a heart having an atrium, comprising:

clamping the tissue between a pair of opposing jaws;

ablating a portion of the tissue at a first generally linear position on the tissue by applying ablative energy to two of a plurality of elongate electrodes, each of the two of the plurality of elongate electrodes being coupled in opposing relationship to each other and the pair of opposing jaws, respectively;

then

sensing an effectiveness of ablation on the portion of the tissue at a second generally linear position on the tissue with at least one of the plurality of elongate electrodes positioned on one of the pair of opposing jaws;

the second linear position on the tissue being laterally distal to the first linear position on the tissue with respect to the atrium.

2. The method of claim 1, wherein the plurality of elongate electrodes are a pair of elongate electrodes.

3. The method of claim 2, further comprising repositioning the pair of opposing jaws after the ablating step to the second generally linear position.

4. The method of claim 1, wherein the plurality of elongate electrodes are at least three electrodes, and wherein the ablating ablates with a first two of the plurality of elongate electrodes of the sensing senses with a third one of the plurality of elongate electrodes.

5. The method of claim 4, wherein the plurality of elongate electrodes are four electrodes;

wherein the ablating ablates the tissue with a first two electrodes of the plurality of elongate electrodes; and

wherein the sensing senses an effectiveness of ablation with a second two electrodes of the plurality of elongate electrodes, each of the second two of the plurality of elongate electrodes being coupled in opposing relationship to each other and the pair of opposing jaws, respectively.

6. The method of claim 5, wherein the two electrodes of the sensing step are positioned generally parallel to the two electrodes of the ablating step.

7. The method of claim 6, wherein the clamping comprises clamping the tissue between the jaws with a first clamping force, and further comprising clamping the tissue between the jaws with a second clamping force after the ablating and before the sensing step, wherein the first clamping force is greater than the second clamping force.

8. The method of claim 2, wherein the clamping comprises clamping the tissue between the jaws with a first clamping force, and further comprising clamping the tissue between the jaws at the second linear position with a second clamping force after the ablating and before the sensing, wherein the first clamping force is greater than the second clamping force.

9. The method of claim 2, wherein the jaws are fluidly coupled to a fluid supply of a fluid, and wherein during the ablating a first amount of the fluid is delivered to the jaws, and wherein during the sensing a second amount of the fluid is delivered to the jaws, the first amount of fluid being greater than the second amount of fluid.

10. The method of claim 9, wherein the first amount and the second amount are a first total volume of the fluid and a second total volume of the fluid, respectively.

11. The method of claim 9, wherein the first amount and the second amount are delivered at a first rate of delivery of the fluid and a second rate of the fluid, respectively.

12. The method of claim 2, wherein the sensing comprises a first test and a second test.

13. The method of claim 12, wherein the first test senses cardiac energy.

14. The method of claim 13, wherein at least one of the pair of elongate electrodes is coupled to a source of pacing energy and wherein the test comprises delivering the pacing energy and detecting a response of the heart to the pacing energy.

15. The method of claim 1, wherein the sensing senses using two of the plurality of electrodes.

16. The method of claim 1, wherein the heart has a right pulmonary vein having a width and a left pulmonary vein having a width, and wherein the first generally linear position spans the width of at least one of the right pulmonary vein and the left pulmonary vein.

17. The method of claim 16, wherein the second generally linear position spans a width of the at least one of the right pulmonary vein and the left pulmonary vein distal of the first generally linear position relative to the atrium.

18. A system for ablating tissue of a heart having an atrium, comprising:

a set of opposing jaws movably coupled with respect to each other;

a plurality of opposing elongate electrodes positioned with respect to the set of jaws;

a source of ablation energy coupled to two opposing ones of the plurality of elongate electrodes and delivering ablation energy to the tissue to form a lesion; and

a sensing module coupled to at least one of the plurality of elongate electrodes which senses a completeness of the lesion.

19. The system of claim 18, wherein the plurality of elongate electrodes is a pair of elongate electrodes.

20. The system of claim 18, wherein the plurality of elongate electrodes is at least three electrodes, and wherein the source of ablation energy is coupled to a first two of the plurality of elongate electrodes and wherein the sensing module is coupled to at least a third of the plurality of elongate electrodes.

21. The system of claim 20, wherein the plurality of elongate electrodes is four electrodes, and wherein the sensing module is coupled to a second two of the plurality of elongate electrodes, wherein the first two elongate electrodes oppose the second two elongate electrodes.

22. The system of claim 21, wherein the first two elongate electrodes are generally parallel to the second two elongate electrodes.

23. The system of claim 18, further comprising a clamp force regulator that is capable of regulating a clamping force applied to the tissue by the set of opposing jaws.

24. The system of claim 23, wherein the clamp force regulator regulates a first clamping force and a second clamping force.

25. The system of claim 23, wherein the first clamping force is greater than the second clamping force.

26. The system of claim 18, further comprising a fluid supply containing a fluid, the fluid supply being fluidly coupled to the set of opposing jaws to deliver a first amount of the fluid corresponding to the source of ablation energy delivering the ablation energy and a second amount of fluid corresponding to the sensing module sensing a completeness of the lesion.

27. The system of claim 26, wherein the first amount of fluid is greater than the second amount of fluid.

28. The system of claim 26, wherein the first amount and the second amount are a first total volume and a second total volume.

29. The system of claim 26, wherein the first amount of fluid and the second amount of fluid are delivered at a first rate of delivery and a second rate of delivery, respectively.

30. The system of claim 18, wherein the sensing module is configured to perform a first test and a second test at the second generally linear position.

31. The system of claim 30, wherein the first test senses cardiac energy.

32. The system of claim 30, wherein the sensing module includes a source of pacing energy and wherein the second test comprises delivering pacing energy to the tissue and detecting a response of the heart to the pacing energy.

33. The system of claim 18, wherein the heart has a right pulmonary vein having a width and a left pulmonary vein having a width, and wherein each of the plurality of opposing elongate electrodes spans the width of at least one of the right pulmonary vein and the left pulmonary vein.

34. An ablation device, comprising:

a set of opposing jaws movably coupled with respect to each other;

a first pair of opposing elongate electrodes positioned with respect to the set of jaws; and

a second pair of opposing elongate electrodes positioned with respect to the set of jaws and generally adjacent and parallel to the first pair of opposing elongate electrodes.

35. The ablation device of claim 34, further comprising a clamp force regulator that is capable of regulating a clamping force applied to the tissue by the set of opposing jaws.

36. The ablation device of claim 35, wherein the clamp force regulator regulates a first clamping force and a second clamping force.

37. The ablation device of claim 36, wherein the first clamping force is greater than the second clamping force.

38. A method for determining an adequacy of a clamping force exerted on tissue by a pair of opposing jaws for ablating the tissue, the pair of opposing jaws comprising at least one electrode, comprising:

clamping the tissue between the pair of opposing jaws with a clamping force;

sensing an amplitude of the cardiac energy with the at least one electrode; and

determining an adequacy of the clamping force based on the amplitude of the cardiac energy.

39. The method of claim 38, further comprising delivering ablation energy to the tissue with the at least one electrode based on the adequacy of the clamping force.

40. The method of claim 39, wherein the clamping force causes the amplitude to be a predetermined minimum value.

41. The method of claim 40, wherein the predetermined minimum value is approximately zero volts.

42. The method of claim 38, further comprising adjusting the clamping force based on the adequacy of the clamping force, and then delivering ablation energy to the tissue with the at least one electrode.

43. The method of claim 42, wherein the clamping force is a first clamping force and the adjusting step adjusts the first clamping force to a second clamping force, the second clamping force being optimized for ablating the tissue.

44. The method of claim 43, wherein the second clamping force causes the amplitude to be a predetermined minimum value.

45. The method of claim 44, wherein the predetermined minimum value is approximately zero volts.

46. The method of claim 38, wherein the at least one electrode is an elongate electrode.

47. The method of claim 38, wherein the at least one electrode is a pair of opposing electrodes positioned with respect to the pair of opposing jaws.

48. A system for sensing an electrical signal in tissue, comprising:

a set of opposing jaws movably coupled with respect to each other;

an electrode positioned with respect to the set of jaws;

a voltage amplitude sensor operatively coupled to the electrode sensing an amplitude of the electrical signal based on a clamping force exerted by the jaws on the tissue when the tissue is clamped between the jaws and the electrode being in electrical contact with the tissue; and

a processor, operatively coupled to the voltage amplitude sensor, determining an adequacy of the clamping force based on the amplitude.

49. The system as in claim 48, further comprising a source of ablation energy operatively coupled to the electrode, wherein the ablation energy is deliverable to the tissue based on the adequacy of the clamping force.

50. The system as in claim 48, further comprising a user interface operatively coupled to the processor, the user interface displaying an indicia indicative of the adequacy of the clamping force.

51. The system as in claim 48, wherein the electrode is an elongate electrode.

52. The system of claim 48, wherein the processor is coupled to the ablation power supply and wherein the power supply is prevented from delivering ablation energy when the amplitude exceeds a predetermined minimum value.

53. The system of claim 48, wherein the processor is coupled to the ablation power supply, and wherein the power supply is prevented from delivering ablation energy when the amplitude exceeds 0.05 mV.