RF apparatus for controlled depth ablation of soft tissue

• US 5,514,130 A
• Filed: 10/11/1994
• Issued: 05/07/1996
• Est. Priority Date: 10/11/1994
• Status: Expired due to Fees

• Current Assignee: Oratec Interventions Incorporated
• Original Assignee: Dorsal Med International Co.
• Inventors: Baker, James
• Primary Examiner(s): Cohen, Lee S.
• Application Number:
  US08/320,304
• Time in Patent Office: 574 Days
• Field of Search: 606/41, 606/46, 606/48, 606/50, 607/98, 607/99, 607/113, 607/116
• US Class Current: 606/41
• CPC Class Codes: A61B 18/1206 Generators therefor
• CPC Class Codes: A61B 18/14 Probes or electrodes therefor
• CPC Class Codes: A61B 18/1402 Probes for open surgery
• CPC Class Codes: A61B 18/1477 Needle-like probes
• CPC Class Codes: A61B 18/148 having a short, rigid shaft for accessing the inner body transcutaneously, e.g. for neurosurgery or arthroscopy
• CPC Class Codes: A61B 18/1482 having a long rigid shaft for accessing the inner body transcutaneously in minimal invasive surgery, e.g. laparoscopy
• CPC Class Codes: A61B 18/1485 having a short rigid shaft for accessing the inner body through natural openings
• CPC Class Codes: A61B 2018/00011 with fluids
• CPC Class Codes: A61B 2018/00053 Mechanical features of the instrument of device
• CPC Class Codes: A61B 2018/00083 low, i.e. electrically insulating
• CPC Class Codes: A61B 2018/00196 reciprocating lengthwise
• CPC Class Codes: A61B 2018/00577 Ablation
• CPC Class Codes: A61B 2018/00702 Power or energy
• CPC Class Codes: A61B 2018/00791 Temperature
• CPC Class Codes: A61B 2018/00875 Resistance or impedance
• CPC Class Codes: A61B 2018/126 bipolar
• CPC Class Codes: A61B 2018/1472 for use with liquid electrolyte, e.g. virtual electrodes
• CPC Class Codes: A61B 2218/002 Irrigation

Abstract

An RF ablation apparatus has a delivery catheter with a delivery catheter lumen and a delivery catheter distal end. A first RF electrode is positioned in the delivery catheter lumen. The first RF electrode has a distal end, RF conductive surface, and a lumen. A second RF electrode has a distal end. The second RF electrode is at least partially positioned in the lumen of the first catheter, with its distal end positioned at the exterior of the first RF electrode distal end. Additionally, the second RF electrode distal end has a geometry that permits it to be substantially a groundpad. The distal end of the first RF electrode is moved in a direction away from the second RF electrode distal end to create a painting effect of an ablation band or line between the two distal ends. Alternatively, the distal end of the second RF electrode can be moved in a direction away from the distal end of the first RF electrode. An RF insulative sleeve or coating is placed or positioned along a second RF electrode conductive surface where it is substantially adjacent to the first electrode conductive surface. An RF power source is coupled to the first and second RF electrodes.

Claims

1. An RF ablation apparatus, comprising:

a delivery catheter with a delivery catheter lumen and a delivery catheter distal end;

a first RF electrode positioned in the delivery catheter lumen, the first RF electrode having a first RF electrode distal end, a first RF electrode conductive surface, and a first RF electrode lumen;

a second RF electrode with a second RF electrode distal end and a second RF electrode conductive surface, the second RF electrode being at least partially positioned in the first RF electrode lumen with the second RF electrode distal end positioned at the exterior of the first RF electrode distal end, the first RF electrode being movable in a direction away from the second electrode distal end creating an ablation between the second RF electrode distal end and the first RF electrode distal end;

an RF insulative sleeve positioned along a selected section of the second RF electrode conductive surface; and

an RF power source coupled to the first and second RF electrodes.

3. The RF ablation apparatus of claim 1, wherein the RF insulative sleeve is positioned along the second RF electrode conductive surface, and the second RF electrode conductive surface is substantially adjacent to the first electrode conductive surface.

2. An RF ablation apparatus, comprising:

a delivery catheter with a delivery catheter lumen and a delivery catheter distal end;

a first RF electrode positioned in the delivery catheter lumen, the first RF electrode having a first RF electrode distal end, a first RF electrode conductive surface, and a first RF electrode lumen;

a second RF electrode with a second RF electrode distal end and a second RF electrode conductive surface, the second RF electrode being at least partially positioned in the first RF electrode lumen with the second RF electrode distal end positioned at the exterior of the first RF electrode distal end, the second RF electrode distal end having a geometry that permits it to be substantially a groundpad, the first RF electrode being movable in a direction away from the second electrode distal end creating an ablation between the second RF electrode distal end and the first RF electrode distal end;

an RF insulative sleeve positioned along a selected section of the second RF electrode conductive surface; and

an RF power source coupled to the first and second RF electrodes.

4. The RF ablation apparatus of claim 2, wherein the distal end of the second electrode is radiused.

5. The RF ablation apparatus of claim 2, wherein the distal end of the second electrode has radiused edges.

6. The RF ablation apparatus of claim 2, wherein at least a portion of the first electrode distal end has a sharp edge.

7. The RF ablation apparatus of claim 2, wherein the first electrode distal end has a non-radiused edge.

8. The RF ablation apparatus of claim 2, further comprising:

a pull wire attached to the first electrode.

9. The RF ablation apparatus of claim 2, further comprising:

a pull wire attached to the second electrode.

10. The RF ablation apparatus of claim 2 wherein the first electrode distal end is deployed laterally in relation to the distal end of the delivery catheter.

11. The RF ablation apparatus of claim 2, wherein the first electrode distal end is made of a memory metal.

12. The RF ablation apparatus of claim 2, wherein the second electrode distal end is deployed laterally in relation to the distal end of the delivery catheter.

13. The RF ablation apparatus of claim 2, wherein the second electrode distal end is made of a memory metal.

14. The RF ablation apparatus of claim 2, wherein the first electrode is slidably movable along the lumen of the delivery catheter.

15. The RF ablation apparatus of claim 2, wherein the first electrode is fixably positioned with the delivery catheter and movable with movement of the delivery catheter.

16. The RF ablation apparatus of claim 2 wherein the first electrode is partially RF insulated.

17. The RF ablation apparatus of claim 2, wherein at least a portion of the first electrode distal end is RF insulated.

18. The RF ablation apparatus of claim 2, wherein at least a portion of the second electrode distal end is RF insulated.

19. The RF ablation apparatus of claim 2, wherein the first electrode is fixed in relation to the delivery catheter.

20. The RF ablation apparatus of claim 2, wherein the first electrode is articulated in relation to the delivery catheter.

21. The RF ablation apparatus of claim 2, wherein the second electrode is fixed in relation to the delivery catheter.

22. The RF ablation apparatus of claim 2, wherein the second electrode is articulated in relation to the delivery catheter.

23. An RF ablation apparatus, comprising:

a delivery catheter with a delivery catheter lumen;

a first RF electrode positioned in the delivery catheter lumen, the first RF electrode having a first RF electrode distal end with an RF conductive surface, and a first RF electrode lumen;

a second RF electrode including an elongated body that terminates at a second RF electrode distal end with an average diameter larger than an average diameter of the elongated body, the second RF electrode being at least partially positioned in the first RF electrode lumen with the second RF electrode distal end positioned at the exterior of the first RF electrode distal end, the first RF electrode being capable of movement in a direction away from the second RF electrode distal end to create an ablation band between the distal end of the second RF electrode and the first RF electrode distal end; and

an RF power source coupled to the first and second RF electrodes.

24. The RF ablation apparatus of claim 23, further comprising:

an RF insulative sleeve positioned along the elongated body of the second RF electrode.

25. The RF ablation apparatus of claim 24, wherein at least a portion of the second electrode distal end is RF insulated.

26. The RF ablation apparatus of claim 23, wherein the distal end of the second RF electrode has a geometry and size making it substantially a groundpad.

27. The RF ablation apparatus of claim 23, wherein the second electrode distal end is radiused.

28. The RF ablation apparatus of claim 23, wherein the second electrode distal end has radiused edges.

29. The RF ablation apparatus of claim 23, wherein the first electrode distal end has a sharp edge.

30. The RF ablation apparatus of claim 23, wherein the RF conductive surface of the first electrode distal end has a sharp edge.

31. The RF ablation apparatus of claim 23, wherein the RF conductive surface of the first electrode distal end has a non-radiused edge.

32. The RF ablation apparatus of claim 23, further comprising:

a pull wire attached to the first electrode.

33. The RF ablation apparatus of claim 23, wherein the first electrode distal end is deployed laterally in relation to a longitudinal axis of the delivery catheter.

34. The RF ablation apparatus of claim 23, wherein the first electrode distal end is made of a memory metal.

35. The RF ablation apparatus of claim 23, wherein the second electrode distal end is deployed laterally in relation to a longitudinal axis of the delivery catheter.

36. The RF ablation apparatus of claim 23, wherein the second electrode distal end is made of a memory metal.

37. The RF ablation apparatus of claim 23, wherein the first electrode is slidably movable along the lumen of the delivery catheter.

38. The RF ablation apparatus of claim 23, wherein the first electrode is fixably positioned to the delivery catheter and movable with a movement of the delivery catheter.

39. The RF ablation apparatus of claim 23, wherein the first electrode is at least partially RF insulated.

40. The RF ablation apparatus of claim 23, wherein at least a portion of the first electrode distal end is RF insulated.

41. The RF ablation apparatus of claim 23, wherein at least a portion of the second electrode distal end is RF insulated.

42. The RF ablation apparatus of claim 23, further comprising:

a feedback device in response to a detected characteristic of the ablation band that provides a controlled delivery of RF energy to the first and second electrodes.

43. The ablation apparatus of claim 42, wherein the detected characteristic is an impedance at a section of the ablation band.

44. The ablation apparatus of claim 42, wherein the detected characteristic is a temperature profile at a section of the ablation band.