Electrosurgical device with floating-potential electrodes

• US 20050065510A1
• Filed: 08/04/2004
• Published: 03/24/2005
• Est. Priority Date: 08/11/2003
• Status: Active Grant

• Current Assignee: ElectroMedical Associates, Inc.
• Original Assignee: ElectroMedical Associates, Inc.
• Inventors: Van Wyk, Robert A., Carmel, Yuval, Shkvarunets, Anatoly
• Granted Patent: US 7,563,261 B2
• Time in Patent Office: Days
• US Class Current: 606/41
• CPC Class Codes: A61B 18/148 having a short, rigid shaft for accessing the inner body transcutaneously, e.g. for neurosurgery or arthroscopy

Abstract

An electrosurgical instrument, system and methods are provided for the vaporization, cutting, coagulation, or treatment of tissue in the presence of an electrically conductive fluid medium. The electrosurgical probe comprises at least one active electrode, and at least one “floating” electrode having at least one end in close proximity to at least one active electrode. The floating electrode is not connected in any way to the electrosurgical power supply, but rather has a “floating” potential determined by the shape and position of the electrode. The floating electrode increases current density in the region of the probe distal end.

Claims

1. An electrosurgical probe comprising:

a shaft having a proximal end and a distal end;

at least one active electrode located at or near said distal end;

a conductor connected to said at least one active electrode;

at least one conductive member disposed at said distal end; and

a dielectric member disposed between the active electrode and the conductive member,

wherein_-said conductive member has a distal portion and a proximal portion with the distal portion being positioned in close proximity to an end of the at least one active electrode;

2. The probe of claim 1 wherein said at least one active electrode and said at least one conductive member are separated by a distance of about 0.1 to 10 millimeters.

3. The probe of claim 2 wherein said at least one active electrode and said at least one conductive member are separated by a distance of about 0.2 to 4 millimeters.

4. The electrosurgical probe of claim 1 wherein said at least one active electrode and the distal portion of said at least one conductive member protrude beyond an end of the dielectric member.

5. The electrosurgical probe of claim 1 wherein said distal portion of said at least one conductive member extends beyond a distal portion of said at least one active electrode.

6. The electrosurgical probe of claim 1 wherein said distal portion of said at least one conductive member is adjacent to a proximal portion of said at least one active electrode.

7. The electrosurgical probe of claim 1 wherein said distal portion of said at least one conductive member extends between a distal and proximal portion of said at least one active electrode.

8. The electrosurgical probe of claim 1 wherein said at least one active electrode comprises a plurality of ribs.

9. The electrosurgical probe of claim 1 wherein said at least one active electrode comprises a plurality of protuberances.

10. The electrosurgical probe of claim 1 wherein said at least one active electrode forms an annulus with the at least one conductive member.

11. The electrosurgical probe of claim 1 wherein said at least one conductive member comprises a plurality of protuberances.

12. The electrosurgical probe of claim 1 wherein said distal portion of said at least one conductive member is tapered.

13. The electrosurgical probe of claim 9 wherein said distal portion of said at least one conductive member forms a distal surface, said surface comprising a plurality of lumens, and said protuberances passing through said lumens and protruding distally beyond the distal surface.

14. The electrosurgical probe of claim 1 wherein said at least one active electrode is composed of an array of active electrode protuberances, and said at least one conductive member is composed of a plurality of protuberances which are interspersed among the array of active electrode protuberances.

15. The electrosurgical probe of claim 1 wherein said dielectric member is made from a refractory material.

16. The electrosurgical probe of claim 1 further comprising a return electrode.

17. The electrosurgical probe of claim 1 further comprising a means for supplying conductive fluid to the region of the probe distal end.

18. The electrosurgical probe of claim 1 further comprising a means for aspirating liquid and ablation products from the region of the probe distal end.

33. The method of claim 17 wherein said distal portion of said at least one conductive member is tapered.

34. The method of claim 17 wherein said probe further comprises a return electrode.

19. A method for intensifying the electric field in the vicinity of the distal end of an electrosurgical probe comprising the steps of:

providing an electrosurgical probe including,

a shaft having a proximal end and a distal end;

at least one active electrode located at or near said distal end;

a conductor connected to said at least one active electrode;

at least one conductive member disposed at said distal end; and

a dielectric member disposed between the at least one active electrode and the at least one conductive member,

wherein at least one conductive member has a distal portion and a proximal portion, said distal portion being positioned in close proximity to an end of the at least one active electrode;

submerging in a conductive liquid; and

applying a high-frequency voltage between the at least one active electrode and a return electrode,

wherein conduction of electric current between the distal portion of the at least one conductive member and the proximal portion of the at least one conductive member creates a region of high current density between the at least one active electrode and the distal portion of the at least one conductive member.

20. The method of claim 19 in which said conductive liquid is bodily fluids from the patient.

21. The method of claim 19 in which said conductive liquid is irrigant supplied to the region surrounding said distal tip of said probe.

22. The method of claim 19 in which said conductive liquid substantially fills a natural or created cavity in the body of a patient.

23. The method of claim 19 wherein said at least one active electrode and said at least one conductive member are separated by a distance of about 0.1 to 10 millimeters.

24. The method of claim 23 wherein said at least one active electrode and said at least one conductive member are separated by a distance of about 0.2 to 4 millimeters.

25. The method of claim 19 wherein said at least one active electrode and said distal end of said at least one conductive member protrude beyond a distal end of the dielectric member.

26. The method of claim 19 wherein said distal end of said at least one conductive member extends beyond an end of said at least one active electrode.

27. The method of claim 19 wherein said distal end of said at least one conductive member is adjacent to a proximal portion of said at least one active electrode.

28. The method of claim 19 wherein said distal end of said at least one conductive member extends between a distal and proximal portion of said at least one active electrode.

29. The method of claim 19 wherein said at least one active electrode comprises a plurality of ribs.

30. The method of claim 19 wherein said at least one active electrode comprises a plurality of protuberances.

31. The method of claim 19 wherein said at least one active electrode forms an annulus with the at least one conductive member.

32. The method of claim 19 wherein said at least one conductive member comprises a plurality of protuberances.

35. The method of claim 30 wherein said distal portion of said at least one conductive member forms a distal surface, said surface comprising a plurality of lumens, wherein said protuberances pass through said lumens and protrude distally beyond said distal surface.

36. The method of claim 19 wherein said at least one active electrode is composed of an array of active electrode protuberances, and said at least one conductive member is composed a plurality of protuberances which are interspersed among the array of active electrode protuberances.

37. The method of claim 19 wherein said dielectric member is made from a refractory material.

38. The method of claim 19 wherein said probe further comprises a means for supplying conductive liquid to the region of the probe distal end.

39. The method of claim 19 wherein said probe further comprises a means for aspirating liquid and ablation products from the region of the probe distal end.

57. The method of claim 36 wherein said dielectric member is made from a refractory material.

58. The method of claim 36 wherein said probe further comprises a return electrode.

59. The method of claim 36 wherein said probe further comprises a means for supplying conductive liquid to the region of the probe distal end.

60. The method of claim 36 wherein said probe further comprises a means for aspirating liquid and ablation products from the region of the probe distal end.

40. A method for ablating tissue at a site on a patient comprising the steps of:

providing an electrosurgical probe including,

a shaft having a proximal end and a distal end;

at least one active electrode located at or near said distal end;

a conductor connected to said at least one active electrode;

at least one conductive member disposed at said distal end; and

a dielectric member disposed between the at least one active electrode and the at least one conductive member,

wherein at least one conductive member has a distal portion and a proximal portion, said distal portion being positioned in close proximity to an end of the at least one active electrode;

positioning a distal end of said probe in close proximity to tissue to be ablated;

submerging the distal end of said probe in a conductive liquid; and

applying high frequency voltage between said at least one active electrode and a return electrode to vaporize a portion of the tissue.

41. The method of claim 40 in which said conductive liquid is bodily fluids from the patient.

42. The method of claim 40 in which said conductive liquid is irrigant supplied to the region surrounding said distal end of said probe.

43. The method of claim 40 in which said conductive liquid substantially fills a natural or created cavity in the body of a patient.

44. The method of claim 40 wherein said at least one active electrode and said at least one conductive member are separated by a distance of about 0.1 to 10 millimeters.

45. The method of claim 44 wherein said at least one active electrode and said at least one conductive member are separated by a distance of about 0.2 to 4 millimeters.

46. The method of claim 40 wherein said at least one active electrode and said distal portion of said at least one conductive member protrude beyond a distal end of the dielectric member.

47. The method of claim 40 wherein said distal portion of said at least one conductive member extends beyond a end of said at least one active electrode.

48. The method of claim 40 wherein said distal portion of said at least one conductive member is adjacent to a proximal portion of said at least one active electrode.

49. The method of claim 40 wherein said distal end of said at least one conductive member extends between a distal and proximal portion of said at least one active electrode.

50. The method of claim 40 wherein said at least one active electrode comprises a plurality of ribs.

51. The method of claim 40 wherein said at least one active electrode comprises a plurality of protuberances.

52. The method of claim 40 wherein said at least one active electrode forms an annulus with the at least one conductive member.

53. The method of claim 40 wherein said at least one conductive member comprises a plurality of protuberances.

54. The method of claim 40 wherein said distal portion of said at least one conductive member is tapered.

55. The method of claim 51 wherein said distal portion of said at least one conductive member forms a distal surface, said surface comprising a plurality of lumens, wherein said protuberances pass through said lumens and protrudes distally beyond said distal surface.

56. The method of claim 40 wherein said at least one active electrode is composed of an array of active electrode protuberances, and said at least one conductive member is composed a plurality of protuberances which are interspersed among the array of active electrode protuberances.

61. A method for thermally treating tissue at a site on a patient comprising the steps of:

providing an electrosurgical probe including,

a shaft having a proximal end and a distal end;

at least one active electrode located at or near said distal end;

a conductor connected to said at least one active electrode;

at least one conductive member disposed at said distal end; and

a dielectric member disposed between the at least one active electrode and the at least one conductive member,

wherein at least one conductive member has a distal portion and a proximal portion, said distal portion being positioned in close proximity to an end of the at least one active electrode;

positioning a distal end of said probe in contact with tissue at the site for thermal treatment of tissue; and

applying high frequency voltage between said at least one active electrode and a return electrode to heat a portion of the tissue.

62. The method of claim 61 comprising the additional step of submerging said distal end of said probe in a conductive liquid.

63. The method of claim 62 in which said conductive liquid is bodily fluids from the patient.

64. The method of claim 62 in which said conductive liquid is irrigant supplied to the region surrounding the distal end of said probe.

65. The method of claim 62 in which said conductive liquid substantially fills a natural or created cavity in the body of a patient.

66. The method of claim 61 wherein said at least one active electrode and said at least one conductive member are separated by a distance of about 0.1 to 10 millimeters.

67. The method of claim 66 wherein said at least one active electrode and said at least one conductive member are separated by a distance of about 0.2 to 4 millimeters.

68. The method of claim 61 wherein said at least one active electrode and said distal portion of said at least one conductive member protrude beyond a distal end of said refractory dielectric member.

69. The method of claim 61 wherein said distal portion of said at least one conductive member extends beyond a end of said at least one active electrode.

70. The method of claim 61 wherein said distal portion of said at least one conductive member is adjacent to a proximal portion of said at least one active electrode.

71. The method of claim 61 wherein said distal end of said at least one conductive member extends between a distal and proximal portion of said at least one active electrode.

72. The method of claim 61 wherein said at least one active electrode comprises a plurality of ribs.

73. The method of claim 61 wherein said at least one active electrode comprises a plurality of protuberances.

74. The method of claim 61 wherein said at least one active electrode forms an annulus with the at least one conductive member.

75. The method of claim 61 wherein said at least one conductive member comprises a plurality of protuberances.

76. The method of claim 61 wherein said distal portion of said at least one conductive member is tapered.

77. The method of claim 73 wherein said distal portion of said at least one conductive member forms a distal surface, said surface comprising a plurality of lumens, wherein said protuberances pass through said lumens and protrude distally beyond said distal surface.

78. The method of claim 61 wherein said at least one active electrode is composed of an array of active electrode protuberances, and said at least one conductive member is composed a plurality of protuberances which are interspersed among the array of active electrode protuberances.

79. The method of claim 61 wherein said probe further comprises a return electrode.

80. The method of claim 62 wherein said probe further comprises a means for supplying conductive liquid to the region of the probe distal end.

81. The method of claim 62 wherein said probe further comprises a means for aspirating conductive liquid from the region of the probe distal end.

82. An electrosurgical probe comprising:

at least one active electrode having a proximal and a distal end;

a conductor connected to said at least one active electrode;

at least one conductive member, and

at least one dielectric member disposed between said at least one active electrode and said at least one conductive member,

wherein the at least one conductive member has a distal portion and a proximal portion, and

wherein at least a portion of the at least one conductive member is positioned in close proximity to at least a portion of the distal end of the active electrode;

83. The electrosurgical probe of claim 82 wherein said at least one dielectric member is made from a refractory material.

84. The probe of claim 82 wherein said at least one active electrode, said at least one dielectric member, and said at least one conductive member together form a blade assembly having a proximal end and a distal end.

85. The probe of claim 82 wherein said blade assembly further comprises at least one edge, at least a portion of said edge comprising at least a portion of said at least one active electrode.

86. The probe of claim 82 wherein said blade assembly is formed of laminations of said at least one active electrode, said at least one dielectric member, and said at least one conductive member.

87. The probe of claim 82 wherein an exposed area of said at least one conductive member is at least twice that of said at least one active electrode.

88. The probe of claim 82 wherein said at least one active electrode and said at least one conductive member are separated by a distance of about 0.1 to 10 millimeters.

89. The probe of claim 82 wherein said at least one active electrode and said at least one conductive member are separated by a distance of about 0.2 to 4 millimeters.

90. The probe of claim 89 wherein said probe further comprises a return electrode.

91. The probe of claim 82 further comprising a means for supplying conductive liquid to the region of the probe distal end.

92. The probe of claim 82 further comprising a means for aspirating liquid and ablation products from the region of the probe distal end.

93. A system for the electrosurgical ablation or thermal treatment of tissue comprising:

a probe comprising;

a shaft having a proximal end and a distal end;

at least one active electrode located at or near said distal end;

a conductor connected to said at least one active electrode;

at least one conductive member disposed at said distal end; and

a dielectric member disposed between the active electrode and the conductive member;

wherein said conductive member has a distal portion and a proximal portion with the distal portion being positioned in close proximity to an end of the at least one active electrode;

an electrosurgical generator;

cabling connecting said probe to said generator; and

a return electrode.

94. The system of claim 93 wherein said at least one active electrode and said at least one conductive member are separated by a distance of about 0.1 to 10 millimeters.

95. The system of claim 94 wherein said at least one active electrode and said at least one conductive member are separated by a distance of about 0.2 to 4 millimeters.

96. The system of claim 93 wherein said at least one active electrode and the distal portion of said at least one conductive member protrude beyond an end of the dielectric member.

97. The system of claim 93 wherein said distal portion of said at least one conductive member extends beyond a distal portion of said at least one active electrode.

98. The system of claim 93 wherein said distal portion of said at least one conductive member is adjacent to a proximal portion of said at least one active electrode.

99. The system of claim 93 wherein said distal portion of said at least one conductive member extends between a distal and proximal portion of said at least one active electrode.

100. The system of claim 93 wherein said at least one active electrode comprises a plurality of ribs.

101. The system of claim 93 wherein said at least one active electrode comprises a plurality of protuberances.

102. The system of claim 93 wherein said at least one active electrode forms an annulus with the at least one conductive member.

103. The system of claim 93 wherein said at least one conductive member comprises a plurality of protuberances.

104. The system of claim 93 wherein said distal portion of said at least one conductive member is tapered.

105. The system of claim 101 wherein said distal portion of said at least one conductive member forms a distal surface, said surface comprising a plurality of lumens, and said protuberances passing through said lumens and protruding distally beyond the distal surface.

106. The system of claim 93 wherein said at least one active electrode is composed of an array of active electrode protuberances, and said at least one conductive member is composed of a plurality of protuberances which are interspersed among the array of active electrode protuberances.

107. The system of claim 93 wherein said dielectric member is made from a refractory material.

108. The system of claim 93 wherein said probe further comprises a return electrode.

109. The system of claim 93 wherein said probe further comprises a means for supplying conductive liquid to the region of the probe distal end.

110. The system of claim 93 wherein said probe further comprises a means for aspirating liquid and ablation products from the region of the probe distal end.