Systems and methods for controlling tissue ablation using multiple temperature sensing elements

• US 5,810,802 A
• Filed: 01/24/1997
• Issued: 09/22/1998
• Est. Priority Date: 08/08/1994
• Status: Expired due to Term

• Current Assignee: EP Technology (Boston Scientific Corporation)
• Original Assignee: EP Technology (Boston Scientific Corporation)
• Inventors: Panescu, Dorin, Swanson, David K., Fleischman, Sidney D., Whayne, James G.
• Primary Examiner(s): PEFFLEY, MICHAEL F
• Application Number:
  US08/788,782
• Time in Patent Office: 606 Days
• Field of Search: 606/27-31, 606/41, 606/42, 606/45-50, 607/100-102, 607/122, 600/373, 600/374, 600/549
• US Class Current: 606/31
• CPC Class Codes: A61B 18/00 Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body eye surgery A61F9/007; ear surgery A61F11/00
• CPC Class Codes: A61B 18/12 by passing a current through the tissue to be heated, e.g. high-frequency current
• CPC Class Codes: A61B 18/1206 Generators therefor
• CPC Class Codes: A61B 18/1492 having a flexible, catheter-like structure, e.g. for heart ablation A61B18/1477 takes precedence
• CPC Class Codes: A61B 18/20 using laser
• CPC Class Codes: A61B 2017/00088 using thermistors
• CPC Class Codes: A61B 2017/00092 using thermocouples
• CPC Class Codes: A61B 2017/00154 pulsed
• CPC Class Codes: A61B 2017/003 Steerable
• CPC Class Codes: A61B 2018/00083 low, i.e. electrically insulating
• CPC Class Codes: A61B 2018/00101 low, i.e. thermally insulating
• CPC Class Codes: A61B 2018/00107 Coatings on the energy applicator
• CPC Class Codes: A61B 2018/00148 with metal
• CPC Class Codes: A61B 2018/0016 Energy applicators arranged in a two- or three dimensional array
• CPC Class Codes: A61B 2018/00636 Sensing and controlling the application of energy
• CPC Class Codes: A61B 2018/0066 without feedback, i.e. open loop control
• CPC Class Codes: A61B 2018/0069 using fuzzy logic
• CPC Class Codes: A61B 2018/00791 Temperature
• CPC Class Codes: A61B 2018/00797 measured by multiple temperature sensors
• CPC Class Codes: A61B 2018/00803 with temperature prediction
• CPC Class Codes: A61B 2018/00821 : measured by a thermocouple
• CPC Class Codes: A61B 2018/124 : switching the output to different electrodes, e.g. sequentially
• CPC Class Codes: A61B 2018/126 : bipolar
• CPC Class Codes: A61B 2018/128 : generating two or more frequencies
• CPC Class Codes: A61B 2018/1435 : Spiral
• CPC Class Codes: A61B 2018/1467 : using more than two electrodes on a single probe
• CPC Class Codes: A61B 5/287 : Holders for multiple electrodes, e.g. electrode catheters for electrophysiological study [EPS]
• CPC Class Codes: A61B 5/6858 : with a distal basket, e.g. expandable basket
• CPC Class Codes: A61L 29/145 : Hydrogels or hydrocolloids
• CPC Class Codes: A61L 31/10 : Macromolecular materials
• CPC Class Codes: A61L 31/145 : Hydrogels or hydrocolloids
• CPC Class Codes: A61N 1/056 : Transvascular endocardial electrode systems
• CPC Class Codes: A61N 1/06 : for high-frequency therapy
• CPC Class Codes: A61N 1/40 : Applying electric fields by inductive or capacitive coupling microwave apparatus A61N5/00; Applying radio-frequency signals
• CPC Class Codes: A61N 1/403 : for thermotherapy, e.g. hyperthermia
• CPC Class Codes: G01K 1/026 : arrangements for monitoring a plurality of temperatures, e.g. by multiplexing
• CPC Class Codes: G01K 3/14 : in respect of space

Abstract

Systems and associated methods place a temperature sensing element in an "edge region" between an energy transmitting electrode and a non-electrically conducting support body, where higher temperatures are likely to exist. Reliable temperature sensing, which is sensitive to variations in temperatures along the electrode, results.

Claims

1. A device for ablating body tissue comprising

a support element made of a material that does not conduct tissue ablation energy,

an electrode carried by the support element for contact with tissue, the electrode being made of a material that transmits ablation energy, the electrode having at least one longitudinal end edge that contacts the material of the support element, and

at least one temperature sensing element carried by and in thermal contact with the electrode and substantially abutting the at least one longitudinal end edge.

2. A device according to claim 1 and further including at least one additional temperature sensing element carried by the electrode away from the at least one edge.

5. A device according to claim 1 or 2 or 3 or 4

wherein the electrode comprises a metallic material attached about the support element.

6. A device according to claim 1 or 2 or 3 or 4

wherein the electrode comprises wire wrapped about the support element.

7. A device according to claim 1 or 2 or 3 or 4

wherein the support element is flexible and includes means for flexing the support element.

8. A device according to claim 7

wherein the electrode is flexible and flexes with the support element.

9. A device according to claim 1 or 2 or 3 or 4

wherein the temperature sensing element comprises a thermistor.

10. A device according to claim 1 or 2 or 3 or 4

wherein the temperature sensing element comprises a thermocouple.

11. A device according to claim 1 or 2 or 3 or 4

and further including at least one additional temperature sensing element carried by the support body.

12. A device according to claim 1 or 2 or 3 or 4

wherein the electrode defines an inside and an outside and the temperature sensing element is carried inside the electrode.

13. A device according to claim 1 or 2 or 3 or 4

wherein the electrode defines an inside and an outside and the temperature sensing element is carried outside the electrode.

3. A device for ablating body tissue comprising

a support element made of a material that does not conduct tissue ablation energy,

an electrode carried by the support element for contact with tissue, the electrode being made of a material that transmits ablation energy, the electrode having opposed longitudinal end edges that contact the material of the support element, and

temperature sensing elements carried by and in thermal contact with the electrode and substantially abutting the opposed longitudinal end edges.

4. A device according to claim 3 and further including at least one additional temperature sensing element carried by the electrode away from the opposed edges.

14. A device for ablating body tissue comprising

a support element made of a material that does not conduct tissue ablation energy,

an array of spaced apart electrodes carried by the support element for contact with tissue, each electrode being made of a material that transmits ablation energy, each electrode having opposed longitudinal end edges that contact the material of the support element, and

at least one temperature sensing element carried by and in thermal contact with one of the electrodes and substantially abutting at least one of its opposed longitudinal end edges.

15. A device according to claim 14

wherein each electrode carries at least one temperature sensing element adjacent to at least one of its opposed edges.

16. A device according to claim 14

wherein the array of electrodes includes a first electrode that begins the array and a second electrode that ends the array, and

wherein both the first and second electrodes carry at least one temperature sensing element adjacent to at least one of its edges.

17. A device according to claim 16

wherein the array of electrodes includes at least one intermediate electrode between the first and second electrodes.

18. A device according to claim 17

wherein the at least one intermediate electrode carries at least one temperature sensing element adjacent to at least one of its edges.

19. A device according to claim 17

wherein the at least one intermediate electrode carries at least one temperature sensing element.

20. A device according to claim 14

wherein the support body carries at least one temperature sensing element.

21. A device according to claim 14

wherein the at least one electrode comprises a metallic material attached about the support element.

22. A device according to claim 14

wherein the at least one electrode comprises wire wrapped about the support element.

23. A device according to claim 14

wherein the support element is flexible and includes means for flexing the support element.

24. A device according to claim 21

wherein the array of electrodes is flexible and flexes with the support element.

25. A device according to claim 14

wherein the temperature sensing element comprises a thermistor.

26. A device according to claim 14

wherein the temperature sensing element comprises a thermocouple.

27. A system for ablating body tissue comprising

a generator for supplying ablation energy,

a support element made of a material that does not conduct ablation energy,

an electrode operably connected to the generator and carried by the support element for contact with tissue, the electrode being made of a material that transmits ablation energy, the electrode having at least one longitudinal end edge that contacts the material of the support element,

at least one temperature sensing element carried by and in thermal contact with the electrode and substantially abutting the at least one longitudinal end edge, and

a controller coupled to the temperature sensing element and the generator to control the supply of ablation energy based, at least in part, upon temperature sensed by the at least one temperature sensing element.

28. A system for ablating body tissue comprising

a generator for supplying ablation energy,

a support element made of a material that does not conduct ablation energy,

an electrode operably connected to the generator and carried by the support element for contact with tissue, the electrode being made of a material that transmits ablation energy, the electrode having opposed longitudinal end edges that contact the material of the support element,

temperature sensing elements carried by and in thermal contact with the electrode and substantially abutting the opposed longitudinal end edges, and

a controller coupled to the temperature sensing elements and the generator to control the supply of ablation energy based, at least in part, upon temperatures sensed by the temperature sensing elements.

29. A system for ablating body tissue comprising

a generator for supplying ablation energy,

a support element made of a material that does not conduct ablation energy,

an electrode operably connected to the generator and carried by the support element for contact with tissue, the electrode being made of a material that transmits ablation energy, the electrode having opposed longitudinal end edges that contact the material of the support element,

temperature sensing elements carried by the electrode the opposed longitudinal end edges, and

a controller coupled to the temperature sensing elements and the generator to control the supply of ablation energy based, at least in part, upon temperatures sensed by the temperature sensing elements,

wherein the controller includes means for selecting a temperature sensed by one of the temperature sensing elements that is higher than a temperature sensed by the other temperature sensing element and for controlling the supply of ablation energy based, at least in part, upon the selected temperature.

30. A system for ablating body tissue comprising

a generator for supplying ablation energy,

a support element made of a material that does not conduct ablation energy,

an array of spaced apart electrodes operably connected to the generator and carried by the support element for contact with tissue, each electrode being made of a material that transmits ablation energy, each electrode having opposed longitudinal end edges that contact the material of the support element, the array including a first electrode that begins the array and a second electrode that ends the array,

first and second temperature sensing elements carried by and in thermal contact with, respectively, the first and second electrodes and substantially abutting one of their respective opposed longitudinal end edges, and

a controller coupled to the first and second temperature sensing elements and the generator to control the supply of ablation energy to the array of electrodes based, at least in part, upon temperatures sensed by the first and second temperature sensing elements.

31. A method for ablating body tissue comprising the steps of

supplying ablation energy to an electrode carried by a support element made of a material that does not conduct ablation energy, the electrode having at least one longitudinal end edge that contacts the material of the support element,

sensing temperature with at least one temperature sensing element carried by and in thermal contact with the electrode and substantially abutting the at least one longitudinal end edge, and

controlling the supply of ablation energy based, at least in part, upon temperature sensed by the at least one temperature sensing element.

32. A method for ablating body tissue comprising the steps of

supplying ablation energy to an electrode carried by a support element made of a material that does not conduct ablation energy, the electrode having opposed longitudinal end edges that contact the material of the support element,

sensing temperatures with temperature sensing elements carried by and in thermal contact with the electrode and substantially abutting the opposed longitudinal end edges, and

controlling the supply of ablation energy based, at least in part, upon temperatures sensed by the temperature sensing elements.

33. A method according to claim 32

wherein, in controlling the supply of ablation energy, a temperature sensed by one of the temperature sensing elements is selected that is higher than a temperature sensed by the other temperature sensing element and the supply of ablation energy is controlled based, at least in part, upon the selected temperature.

34. A method for ablating body tissue comprising the steps of

supplying ablation energy to an array of spaced apart electrodes carried by a support element made of a material that does not conduct ablation energy, each electrode in the array having opposed longitudinal end edges that contact the material of the support element, the array including a first electrode that begins the array and a second electrode that ends the array,

sensing temperatures with first and second temperature sensing elements carried by and in thermal contact with, respectively, the first and second electrodes and substantially abutting one of their respective opposed longitudinal end edges, and

controlling the supply of ablation energy to the array of electrodes based, at least in part, upon temperatures sensed by the first and second temperature sensing elements.

35. A device for ablating body tissue, comprising:

a support element defining a length made of material that does not conduct tissue ablation energy;

an electrode carried by the support element for contact with tissue made of material that transmits ablation energy, the electrode defining first and second longitudinal end edges, an interior surface, an exterior surface and a length from the first longitudinal end edge to the second longitudinal end edge that is substantially less than the length of the support element, the first and second longitudinal end edges being in contact with the material that does not conduct tissue ablation energy; and

a temperature sensing element carried by and in thermal contact with the electrode, the temperature sensing element being located on one of the interior surface and the exterior surface of the electrode and substantially closer to the first longitudinal end edge than to the second longitudinal end edge.

36. A device as claimed in claim 35, wherein the temperature sensing element substantially abuts the first longitudinal edge of the electrode.

37. A device as claimed in claim 35, wherein the support element defines a distal tip and the electrode is in spaced relation to the distal tip of the support element.

38. A device as claimed in claim 35, wherein the temperature sensing element defines a first temperature sensing element, the device further comprising:

a second temperature sensing element carried by the electrode.

39. A device as claimed in claim 38, wherein the first temperature sensing element substantially abuts the first longitudinal edge of the electrode and the second temperature sensing element substantially abuts the second longitudinal edge of the electrode.

40. A device as claimed in claim 35, wherein the electrode comprises an array of electrodes including first and second electrodes defining longitudinal ends of the array, and the first and second electrodes include respective temperature sensing elements.

41. A device as claimed in claim 40, wherein the array includes a third electrode located between the first and second electrodes, and the third electrode includes a temperature sensing element.

42. A device for ablating body tissue, comprising:

a support element made of material that does not conduct tissue ablation energy;

an electrode carried by the support element for contact with tissue made of material that transmits ablation energy, the electrode defining first and second longitudinal edges, an interior surface and an exterior surface, the first and second longitudinal end edges being in contact with the material that does not conduct tissue ablation energy; and

a temperature sensing element carried by and in thermal contact with the electrode, the temperature sensing element being located on the exterior surface of the electrode and substantially abutting the first longitudinal end edge.

43. A device as claimed in claim 42, wherein the support element defines a distal tip and the electrode is in spaced relation to the distal tip of the support element.

44. A device as claimed in claim 42, wherein the temperature sensing element defines a first temperature sensing element, the device further comprising:

a second temperature sensing element carried by the electrode.

45. A device as claimed in claim 44, wherein the second temperature sensing element substantially abuts the second longitudinal end edge of the electrode.

46. A device as claimed in claim 42, wherein the electrode comprises an array of electrodes including first and second electrodes defining the longitudinal ends of the array, and the first and second electrodes include respective temperature sensing elements.

47. A device as claimed in claim 46, wherein the array includes a third electrode located between the first and second electrodes, and the third electrode includes a temperature sensing element.

48. A device for ablating body tissue, comprising:

a support element made of material that does not conduct tissue ablation energy;

an electrode carried by the support element for contact with tissue made of material that transmits ablation energy, the electrode defining first and second longitudinal end edges, an interior surface and an exterior surface, the first and second longitudinal end edges being in contact with the material that does not conduct tissue ablation energy; and

temperature sensing means for sensing the temperature of the first longitudinal end edge of the electrode.

49. A device as claimed in claim 48, wherein the temperature sensing means defines first temperature sensing means, the device further comprising:

second temperature sensing means for sensing the temperature of the second longitudinal end edge of the electrode.

50. A device as claimed in claim 48, wherein the temperature sensing means is associated with the outer surface of the electrode.