Selectively controlled active electrodes for electrosurgical probe

• US 20060095031A1
• Filed: 09/22/2005
• Published: 05/04/2006
• Est. Priority Date: 09/22/2004
• Status: Abandoned Application

• Current Assignee: ArthroCare Corporation (Smith & Nephew PLC)
• Original Assignee: ArthroCare Corporation (Smith & Nephew PLC)
• Inventors: Ormsby, Theodore C.
• Application Number:
  US11/233,556
• Publication Number:
  US 20060095031A1
• Time in Patent Office: Days
• US Class Current: 606/41
• CPC Class Codes: A61B 18/1233 with circuits for assuring patient safety
• CPC Class Codes: A61B 18/1445 at the distal end of a shaft, e.g. forceps or scissors at the end of a rigid rod
• CPC Class Codes: A61B 18/1482 having a long rigid shaft for accessing the inner body transcutaneously in minimal invasive surgery, e.g. laparoscopy
• CPC Class Codes: A61B 2018/124 switching the output to different electrodes, e.g. sequentially

Abstract

Electrosurgical systems, apparatus and methods for selectively applying electrical energy to body tissue in order to ablate, contract, coagulate, or otherwise modify a target tissue of a patient. An aspect of the invention includes an active electrode assembly having two active electrodes which may be controllably selected to vary the level of energy applied to the tissue. An electrosurgical apparatus of the invention includes a shaft having an articulated electrode support at a distal end of the shaft, the electrode support bearing at least one active electrode on a surface of the electrode support.

Claims

1. An electrosurgical system, comprising:

an electrode assembly comprising first and second active electrodes and a return electrode;

a power supply having first and second opposite poles, the active electrodes and the return electrode coupled to the first and second opposite poles, and the power supply adapted for applying a high frequency voltage between the active electrodes and the return electrode; and

an electronic switch coupled to the power supply and to the first and second active electrodes for switching the first and second active electrodes from an ablation mode to a sub-ablation mode.

2. The system of claim 1, wherein a high frequency voltage is applied to the first and second active electrodes when in the sub-ablation mode and wherein a high frequency voltage is applied to the first active electrode and not to the second active electrode when in the ablation mode.

3. The system of claim 1, wherein the first and second active electrodes are in a serial relationship with each other wherein, when the switch is an open state, the active electrodes are in the sub-ablation mode and, when the switch is in a closed state, the active electrodes are in the ablation mode.

4. The system of claim 1, wherein the first and second active electrodes are in a parallel relationship with each other wherein, when the switch is in open state, the active electrodes are in the ablation mode and, when the switch is in closed state, the active electrodes are in the sub-ablation mode.

5. The system of claim 1, further comprising a voltage sensor coupled to the power supply and the electronic switch for sensing the voltage across the switch.

6. The system of claim 1, further comprising means for switching the switch from a closed state to an open state and visa-versa.

7. The system of claim 1, further comprising a probe having a shaft distal end bearing an articulatable electrode support wherein the active electrodes are disposed on the support.

10. The probe of claim 1 wherein said at least two active electrodes collectively have a surface area about equal to that of the return electrode.

18. The probe of claim 10 wherein said at least two active electrodes have an unequal surface area.

8. A method of modifying a target tissue of a patient, the method comprising:

selectively controlling a switch to apply a high frequency voltage from a power supply to at least two active electrodes and a return electrode causing coagulation to the target tissue wherein said switch may be controlled to apply voltage to only one active electrode and the return electrode thereby causing ablation of said tissue.

9. The method of claim 8, further comprising sensing the voltage level of the switch.

11. An electrosurgical probe, comprising:

a shaft having a shaft distal end and a shaft proximal end;

an active electrode support articulatable with respect to the shaft distal end;

at least one active electrode disposed on a surface of the electrode support; and

a return electrode support extending distally from the shaft distal end, wherein the return electrode support is adapted for discharging and containing an electrically conductive fluid in apposition to the electrode support surface.

12. The probe of claim 11 wherein the at least one active electrode comprises a wire form.

13. The probe of claim 11 wherein the at least one active electrode comprises a screen configuration.

14. The probe of claim 11 wherein the return electrode support comprises a return electrode which forms at least a portion of the return electrode support.

15. The probe of claim 11 wherein the return electrode support has a hollowed or concave configuration.

16. The probe of claim 15 wherein the active electrode support is articulatable between an open and a closed position wherein the at least one active electrode extends within the hollowed return electrode support when the active electrode support is in a closed position.

17. The probe of claim 11 wherein the return electrode support comprises a return electrode comprising a wire form positioned on an outside surface of the return electrode support.