Electrosurgical instrument

• US 6,565,560 B1
• Filed: 03/27/2000
• Issued: 05/20/2003
• Est. Priority Date: 07/18/1997
• Status: Expired due to Fees

• Current Assignee: Gyrus Medical Limited (Olympus Corporation)
• Original Assignee: Gyrus Medical Limited (Olympus Corporation)
• Inventors: Syrop, Alan N, Goble, Colin CO, Goble, Nigel M
• Primary Examiner(s): Kearney; Rosiland S.
• Application Number:
  US09/462,927
• Time in Patent Office: 1,149 Days
• Field of Search: 606/41,42,45-50,167,171,180 604/22
• US Class Current: 606/41
• CPC Class Codes: A61B 18/1485 having a short rigid shaft for accessing the inner body through natural openings
• CPC Class Codes: A61B 18/149 bow shaped or with rotatable body at cantilever end, e.g. for resectoscopes, or coagulating rollers

Abstract

An electrosurgical instrument is provided for the treatment of tissue in the presence of an electrically-conductive fluid medium. The instrument comprises an instrument shaft (10), a tissue treatment electrode (12) at one end of the shaft, and removal means, the instrument having an apertured portion (20a) through which matter can be aspirated by the removal means from the region surrounding the tissue treatment electrode. The removal means comprises a channel formed within the instrument shaft (10) and leading from the apertured portion (20a). The channel is provided with agitation means (14) for preventing the build-up of sublimation products within the channel.

Claims

1. An electrosurgical instrument for the treatment of tissue in the presence of an electrically-conductive fluid medium, the instrument comprising:

an instrument shaft,

a tissue treatment electrode mounted at the distal end of the shaft,

removal means comprising a channel formed within the instrument shaft, and

an apertured portion through which matter can be aspirated by the removal means from the region surrounding the tissue treatment electrode, the removal means extending from the apertured portion,

wherein the channel is provided with agitation means movable relative thereto, the agitation means being a rod mounted within and movable relative to the instrument shaft, the rod being rotatable within the channel and formed with a portion off-set from the longitudinal axis of the instrument shaft,

whereby the off-set portion rotates within the channel around the longitudinal axis of the instrument shaft when the rod is rotated within the channel.

2. An electrosurgical instrument as claimed in claim 1, further comprising drive means for moving the tissue treatment electrode relative to the distal end of the shaft.

3. An electrosurgical instrument as claimed in claim 1, further comprising a return electrode which is electrically insulated from the tissue treatment electrode by insulation means, the tissue treatment electrode being exposed at the distal end of the instrument, and the return electrode having a fluid contact surface spaced proximally from the exposed end of the tissue treatment electrode.

4. An electrosurgical instrument as claimed in claim 3, wherein the tissue treatment electrode is movable cyclically relative to the return electrode so as to move the tissue treatment electrode into, and out of, at least one position in which arcing occurs between the tissue treatment and return electrode.

5. An electrosurgical instrument as claimed in claim 3, wherein the agitation means is constituted by a rod mounted within, and movable relative to, the instrument shaft.

6. An electrosurgical instrument as claimed in claim 5, wherein the tissue treatment electrode is constituted by the distal end portion of the rod.

7. An electrosurgical instrument as claimed in claim 6, wherein the rod is constituted by a tungsten wire having a diameter in the range of from 0.2 mm to 1.0 mm.

8. An electrosurgical instrument as claimed in claim 7, wherein the tungsten wire has a diameter in the range of from 0.4 mm to 0.6 mm.

9. An electrosurgical instrument as claimed in claim 6, wherein the tissue treatment electrode is angled with respect to the longitudinal axis of the instrument shaft.

10. An electrosurgical instrument as claimed in claim 9, further comprising an insulating sleeve surrounding the rod proximally of said angled end portion.

11. An electrosurgical instrument as claimed in claim 10, wherein the insulating sleeve is a ceramic sleeve.

12. An electrosurgical instrument as claimed in claim 9, wherein the angled end portion of the rod is at right-angles to the longitudinal axis of the instrument shaft, and the tip of the angled end portion constitutes the tissue contacting portion of the tissue treatment electrode.

13. An electrosurgical instrument as claimed in claim 6, wherein the insulation means comprises an insulation member provided at the distal end of the instrument shaft, the insulation member defining said apertured portion.

14. An electrosurgical instrument as claimed in claim 13, wherein the insulation member is formed with a slot which constitutes the apertured region, the tissue treatment electrode passing through the slot.

15. An electrosurgical instrument as claimed in claim 13, wherein the apertured portion is constituted by a gap between the tissue treatment electrode and the insulation member.

16. An electrosurgical instrument as claimed in claim 6 further comprising drive means for moving the tissue treatment electrode relative to the distal end of the shaft, and wherein the drive means is such as to reciprocate the rod within the channel.

17. An electrosurgical instrument as claimed in claim 16, wherein the drive means is constituted by a motor and coupling means for converting the rotary output of the motor into reciprocatory movement of the rod.

18. An electrosurgical instrument as claimed in claim 6 further comprising drive means for moving the tissue treatment electrode relative to the distal end of the shaft, and wherein the drive means is such as to rotate the rod within the channel.

19. An electrosurgical instrument as claimed in claim 18, wherein an electric motor constitutes the drive means.

20. An electrosurgical instrument as claimed in claim 18, wherein the rod is formed with a portion off-set from the longitudinal axis of the instrument shaft.

21. An electrosurgical instrument as claimed in claim 18, wherein the angled end portion of the rod is at right-angles to the longitudinal axis of the instrument shaft, and the distal end surface of said angled end portion constitutes the tissue contacting portion of the tissue treatment electrode.

22. An electrosurgical instrument as claimed in claim 18, wherein the angled end portion of the rod makes an acute angle with the longitudinal axis of the instrument shaft.

23. An electrosurgical instrument as claimed in claim 18, wherein the angled end portion of the rod is bent back around the distal end portion of the insulating sleeve.

24. An electrosurgical instrument as claimed in claim 8, further comprising an RF generator having a bipolar output connected to the tissue treatment electrode and the return electrode.

25. An electrosurgical instrument as claimed in claim 24, wherein the pump is controlled in dependence upon the output characteristics of the RF generator.

26. An electrosurgical instrument as claimed in claim 1, wherein the channel is defined by the instrument shaft.

27. An electrosurgical instrument as claimed in claim 1, wherein the removal means further comprises a pump connected to the channel at a region thereof remote from the apertured portion of the instrument.

28. An electrosurgical instrument as claimed in claim 27, wherein the pump is activated cyclically whereby matter is aspirated by the removal means in a pulsed fashion.

29. An electrosurgical instrument as claimed in claim 28, wherein the pump is activated only when the tissue treatment electrode is powered for tissue vaporisation.

30. An electrosurgical instrument for the treatment of tissue in the presence of an electrically-conductive fluid medium, the instrument comprising:

an instrument shaft,

a tissue treatment electrode mounted at the distal end of the shaft, a return electrode electrically insulated from the tissue treatment electrode by an insulation member, removal means, and

drive means for moving the tissue treatment electrode relative to the distal end of the shaft,

the instrument having an apertured portion through which matter can be aspirated by the removal means from the region surrounding the tissue treatment electrode, the removal means comprising a channel formed within the instrument shaft and leading from the apertured portion,

the channel being provided with agitation means movable relative thereto, the agitation means being constituted by a rod mounted within, and movable relative to, the instrument shaft, the rod including an end portion angled with respect to the instrument'"'"'s shaft'"'"'s longitudinal axis,

the tissue treatment electrode being constituted by the distal end portion of the rod,

the drive means rotating the rod within the channel,

wherein the angled portion of the rod makes an acute angle with the longitudinal axis of the instrument shaft, and

wherein the insulation member is provided with an inclined cam surface which is engagable with the apex of the angled end portion of the rod.

31. An electrosurgical instrument for the treatment of tissue in the presence of an electrically-conductive fluid medium, the instrument comprising:

an instrument shaft,

a tissue treatment electrode mounted at the distal end of the shaft and being exposed at the distal end of the instrument,

removal means,

an apertured portion through which matter can be aspirated by the removal means from the region surrounding the tissue treatment electrode,

the removal means comprising a channel formed within the instrument shaft and leading from the apertured portion, the channel being provided with agitation means therein and movable relative thereto,

the agitation means being a rod having a portion off-set from the longitudinal axis of the shaft, the rod and off-set portion being rotatable within the channel,

drive means for moving the agitation means, whereby the tissue treatment electrode is moved relative to the distal end of the shaft, and

a return electrode which is electrically insulated from the tissue treatment electrode by insulation means and having a fluid contact surface spaced proximally from the exposed end of the tissue treatment electrode,

an RF generator having a bipolar output connected to the tissue treatment electrode and the return electrode,

wherein the RF generator supplies energy to the drive means.