Methods and devices for electrosurgery

• US 20030036753A1
• Filed: 04/09/2002
• Published: 02/20/2003
• Est. Priority Date: 08/15/2001
• Status: Active Grant

• Current Assignee: Nuortho Surgical Inc.
• Original Assignee: Map Technologies LLC (MIN AIK Technology Company Limited)
• Inventors: Morgan, Roy E., Auge, Wayne K. II, Prakash, N. Mani
• Granted Patent: US 6,902,564 B2
• Time in Patent Office: Days
• US Class Current: 606/32
• CPC Class Codes: A61B 18/042 using additional gas becoming plasma
• CPC Class Codes: A61B 18/06 caused by chemical reaction , e.g. moxaburners
• CPC Class Codes: A61B 18/14 Probes or electrodes therefor
• CPC Class Codes: A61B 18/1815 using microwaves
• CPC Class Codes: A61B 2018/00434 Neural system
• CPC Class Codes: A61B 2018/00577 Ablation
• CPC Class Codes: A61B 2018/1213 creating an arc

Abstract

Method and devices for electrosurgery by means of oxy-hydro combustion. Deleterious effects to tissue are minimized by means of control of acid-base shift reactions, which reactions can further be employed to control oxy-hydro combustion reactions. In one embodiment, radiofrequency energy in electrical connection with electrodes is employed to induce electrolysis in an aqueous salt environment, thereby producing oxygen and hydrogen, with the same energy source employed to initiate a combustion reaction.

Claims

1. A method of performing an electrosurgical procedure on a patient, the method comprising:

providing a surgical probe including an active electrode and a return electrode separated by an insulator;

providing an aqueous salt ion environment at the location wherein the electrosurgical procedure is to be performed, the environment comprising sufficient volume to permit immersion of at least the portion of the surgical probe including the active electrode and return electrode; and

applying current to a circuit comprising the active electrode and return electrode, the current being less than that required to induce plasma ionization;

whereby the application of current induces electrolysis of a portion of the aqueous salt ion environment thereby producing hydrogen and oxygen and further initiates a hydrogen and oxygen combustion reaction.

2. The method of claim 1, wherein the active electrode further comprises an alloy that induces release of hydrogen.

3. The method of claim 2, wherein the alloy is a member selected from the group consisting of a magnesium alloy and a rare earth metal and nickel alloy.

4. The method of claim 1, wherein the aqueous salt ion environment comprises a salt ion selected from the group consisting of sodium chloride, calcium chloride, magnesium bromide, magnesium iodide, potassium iodide, potassium chloride, lithium bromide and lithium chloride.

5. The method of claim 1, wherein the current applied comprises a high frequency voltage difference.

6. The method of claim 5, wherein the high frequency voltage difference applied comprises radiofrequency (RF) energy.

7. The method of claim 1, wherein the insulator comprises an electrical and thermal insulator.

8. The method of claim 1, wherein the aqueous salt ion environment comprises naturally occurring biological fluids of the patient.

9. The method of claim 1, wherein the aqueous salt ion environment comprises an exogenous aqueous salt ion solution.

10. A method for inducing a therapeutic response in living tissue while minimizing deleterious acid-base shifts in the living tissue, the method comprising:

providing a probe including an active electrode and a return electrode separated by an insulator, the active electrode being disposed within an elongated lumen;

providing an aqueous salt ion solution at the site wherein the therapeutic response is desired, the solution comprising sufficient volume to permit immersion of at least the portion of the probe including the active electrode disposed within the elongated lumen and the return electrode;

positioning the active electrode in close proximity to the location wherein the therapeutic response is desired, the active electrode and return electrode being immersed in the aqueous salt ion solution; and

applying a high frequency voltage between the active electrode and return electrode, the voltage being less than that required to induce plasma ionization.

11. The method of claim 10, wherein acid-base shifts resulting from application of the high frequency voltage are partially contained within the lumen.

12. The method of claim 10, wherein the active electrode and return electrode separated by an insulator are disposed within the elongated lumen.

13. The method of claim 10, wherein the position of the active electrode along the long axis of the lumen is adjustable.

14. The method of claim 13, further comprising controlling the desired therapeutic response by adjusting the position of the active electrode along the long axis of the lumen.

15. The method of claim 10, wherein minimal tissue necrosis is induced at the site wherein the therapeutic response is desired.

16. The method of claim 10, wherein the active electrode further comprises an alloy that induces release of hydrogen.

17. The method of claim 16, wherein the alloy is a member selected from the group consisting of a magnesium alloy and a rare earth metal and nickel alloy.

18. The method of claim 10, wherein the aqueous salt ion solution comprises a salt ion selected from the group consisting of sodium chloride, calcium chloride, magnesium bromide, magnesium iodide, potassium iodide, potassium chloride, lithium bromide and lithium chloride.

19. The method of claim 10, wherein the high frequency voltage comprises radiofrequency (RF) energy.

20. The method of claim 10, wherein the insulator comprises an electrical and thermal insulator.

21. The method of claim 10, wherein the therapeutic response comprises a member selected from the group consisting of nerve ablation, tissue ablation, tissue cutting, tissue coagulation, tissue modification, and induction of host healing response.

22. A method for decreasing tissue necrosis at a site wherein high frequency voltage is applied to an active electrode immersed in an aqueous salt ion solution, the method comprising means for minimizing the acid-base shift at the site.

23. The method of claim 22, wherein the acid-base shift at the site does not cause deleterious alterations in tissue at the site.

24. The method of claim 22, wherein the means for minimizing the acid-base shift at the site comprises application of high frequency voltage less than that required to induce plasma ionization.

25. The method of claim 22, wherein the means for minimizing the acid-base shift at the site comprises application of high frequency voltage to an active electrode disposed within an elongated lumen, the active electrode being proximal the site.

26. The method of claim 25, wherein the active electrode is movably disposed along the long axis within the elongated lumen, the method further comprising minimizing the acid-base shift at the site by adjusting the position of the active electrode along the long axis of the lumen.

27. An apparatus for performing surgical procedures, the apparatus comprising:

first and second gas delivery channels disposed within an elongated housing having a proximal and distal end;

first and second gas connectors at the proximal end for connecting the first and second gas delivery channels to a first and second gas source;

a gas mixing plenum chamber with an inlet and an outlet at the distal end of the elongated housing, the first and second gas delivery channels being in fluid connection with the inlet; and

an active electrode connected to a current source, the active electrode proximal to the gas mixing plenum chamber outlet.

28. The apparatus of claim 27, further comprising a flame arrester positioned between the gas mixing plenum chamber outlet and the active electrode.

29. The apparatus of claim 27 wherein the gas mixing plenum chamber outlet further comprises an acceleration throat.

30. The apparatus of claim 27 wherein the active electrode comprises an alloy that induces release of hydrogen.

31. The apparatus of claim 30 wherein the alloy is a member selected from the group consisting of a magnesium alloy and a rare earth metal and nickel alloy.

32. The apparatus of claim 27 wherein the active electrode comprises a gas porous structure.

33. The apparatus of claim 27 further comprising a return electrode.

34. The apparatus of claim 33 wherein the return electrode is in a fixed position proximal the active electrode.

35. An electrosurgical apparatus comprising:

a housing having proximal and distal ends;

an active electrode disposed adjacent the distal end of the housing, the electrode comprising an alloy that induces release of hydrogen; and

an electrical connector extending from the active electrode to the proximal end of the housing for connecting the electrode to a source of current.

36. The apparatus of claim 35 wherein the alloy is a member selected from the group consisting of a magnesium alloy and a rare earth metal and nickel alloy.

37. The apparatus of claim 35 wherein the alloy induces release of hydrogen upon the application of current.

38. An electrosurgical apparatus comprising:

an elongated lumen having proximal and distal ends;

an active electrode adjustably positionable within and along the long axis of the lumen; and

an electrical connector extending from the active electrode connecting the electrode to a source of current.

39. The apparatus of claim 38, the apparatus further comprising a return electrode fixed in position relative to the active electrode.

40. The apparatus of claim 38 wherein the elongated lumen comprises an insulating material.

41. The apparatus of claim 40 wherein the insulating material is an electrically insulating material.

42. The apparatus of claim 40 wherein the insulating material is thermally insulating material.

43. The apparatus of claim 38 wherein the active electrode is movably adjustable within and along the long axis of the lumen during operation of the apparatus.

44. The apparatus of claim 38 wherein the active electrode is adjustably positionable beyond the distal end of the lumen.

45. The apparatus of claim 38 wherein the distal end of the lumen comprises a segment of a cone.

46. An apparatus for electrosurgery, comprising

an active electrode;

a return electrode fixed in position relative to the active electrode; and

a radiofrequency power supply in electrical connection with the active electrode and return electrode, the power supply generating less radiofrequency power than that required to induce plasma ionization;

whereby on immersion of the active electrode and return electrode in an aqueous salt ion environment, the application of radiofrequency power induces electrolysis of a portion of the aqueous salt ion environment thereby producing hydrogen and oxygen and further initiates a hydrogen and oxygen combustion reaction.