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1. WO2017136414 - ARTHROSCOPIC DEVICES AND METHODS

Note: Text based on automatic Optical Character Recognition processes. Please use the PDF version for legal matters

WHAT IS CLAIMED IS:

1. A medical device for removing tissue in a patient, comprising:

an elongated sleeve with a dielectric cutting member extending distally from a distal end of the sleeve;

a window with at least one sharp cutting edge in the cutting member; an electrode carried by the cutting member circumferentially spaced-apart from the window;

a motor drive configured to couple to a proximal end of the elongated sleeve to rotate the cutting member.

2. The medical device of claim 1, wherein the window opens to a central channel of the cutting member that communicates with an interior channel in the sleeve connected to a negative pressure source.

3. The medical device of claim 1, wherein the cutting member comprises a wear-resistant ceramic material.

4. The medical device of claim 1, wherein the electrode is circumferentially spaced-apart from the window by 180°.

5. The medical device of claim 1, wherein the elongated sleeve extends along a longitudinal axis and the at least one sharp cutting edge is aligned generally with the longitudinal axis.

6. The medical device of claim 1, wherein the window has first and second sides that define two sharp cutting edges aligned generally with the longitudinal axis.

7. The medical device of claim 2, wherein the electrode has micropores therein that communicate with the central channel of the ceramic member and the negative pressure source.

8. The medical device of claim 7, wherein the micropores comprise channels having a diameter ranging between 10 micrometers and 100 micrometers.

9. The medical device of claim 7, wherein micropores comprise channels having a diameter ranging between 20 micrometers and 50 micrometers.

10. The medical device of claim 1, wherein the electrode has a surface area ranging from 1 mm2 to 10 mm2.

11. The medical device of claim 1, wherein the electrode has a surface area ranging from 2 mm2 to 5 mm2.

12. A device for removing tissue in a patient, said device comprising:

a shaft having a longitudinal axis and including (i) an outer sleeve having a distal region with an outer window and an axial bore therethrough and (2) an inner sleeve axis rotationally disposed in the axial bore of the outer sleeve;

a dielectric cutting member having a longitudinal axis carried at a distal end of the inner sleeve, wherein the dielectric cutting member has an inner window with at least one sharp cutting edge; and

an electrode disposed on an exterior surface of the cutting member so that the inner sleeve can be rotated relative to the outer sleeve to expose the electrode through the outer window of the outer sleeve.

13. The medical device of claim 12, wherein the cutting member is cylindrical and the inner window has two circumferentially spaced-apart edges wherein at least one of said edges carries or defines the sharp cutting edge.

14. The medical device of claim 12, wherein each of the two circumferentially spaced-apart edges defines or carries a sharp cutting edge.

15. The medical device of claiml2, wherein the electrode is circumferentially spaced-apart from the at least one sharp cutting edge of the inner window.

16. The medical device of claim 12, wherein the electrode is circumferentially spaced-apart 180° from the inner window.

17. The medical device of claim 12, further comprising a motor drive configured to be detachably coupled to the shaft to rotate the inner sleeve and the cutting member relative to the outer sleeve.

18. The medical device of claim 17, wherein the motor drive includes a controller configured automatically stopping rotation of the inner sleeve and cutting member relative to the outer sleeve to position the electrode within said outer window.

19. The medical device of claim 17, further comprising a rotational position sensor that senses the relative rotational positions of the inner sleeve and the outer sleeve and delivers the positional information to the controller, wherein the controller uses the positional information to position the inner sleeve and cutting member relative to the outer sleeve when stopping rotation of the inner sleeve to position the electrode within said outer window.

20. The medical device of claim 12, wherein the cutter member comprises an electrically insulating ceramic material.

21. The medical device of claim 20, wherein the inner and outer sleeves of the shaft comprise an electrically conductive metal, further comprising an electrically insulating layer between an interior surface of the axial bore of the outer sleeve and an exterior surface of the inner sleeve.

22. The medical device of claim 21, wherein the electrode is electrically coupled to the inner sleeve.

23. The medical device of claim 12, wherein the electrode has micropores therein that communicate with a central channel of the cutting member and a negative pressure source.

24. The medical device of claim 23, wherein the micropores comprise channels having a diameter ranging between 10 micrometers and 100 micrometers.

25. The medical device of claim 23, wherein micropores comprise channels having a diameter ranging between 20 micrometers and 50 micrometers.

26. The medical device of claim 12, wherein the electrode has a surface area ranging from 1 mm2 to 10 mm2.

27. The medical device of claim 12, wherein the electrode has a surface area ranging from 2 mm2 to 5 mm2.

28. A method for removing tissue in a patient, said method comprising:

positioning a distal end of a shaft at a tissue target site submerged in a conductive fluid so that an outer window of an outer sleeve of the shaft is engaged against a target tissue;

rotating an inner window of a ceramic cutting member carried by an inner sleeve of the shaft relative to the outer window of the outer sleeve of the shaft to shear target tissue engaged by the windows;

stopping rotation of the inner sleeve to expose an electrode on the ceramic cutting member in the outer window;

engaging the exposed electrode against target tissue; and

delivering electrical current through the electrode to the target tissue engaged by the electrode.

29. The method of claim 28, wherein the current is radiofrequency current delivered to cauterize or ablate tissue at a location where tissue had been sheared by rotation of the inner window.

30. The method of claim 28, wherein the electrode has micropores therein that communicate with a central channel of the cutting member and a negative pressure source, further comprising a step of applying negative pressure to the micropores to prevent bubble formation at the surface of the electrode.