Method and apparatus for creating a bi-polar virtual electrode used for the ablation of tissue

• US 6,962,589 B2
• Filed: 01/08/2004
• Issued: 11/08/2005
• Est. Priority Date: 07/07/1998
• Status: Expired due to Term

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Hoey, Michael F., Mulier, Peter M. J.
• Primary Examiner(s): Cohen, Lee S.
• Application Number:
  US10/754,768
• Publication Number:
  US 20040143259A1
• Time in Patent Office: 670 Days
• Field of Search: 606/41, 606/48, 606/50, 604/114, 607/99, 607/105, 607/11
• US Class Current: 606/41
• CPC Class Codes: A61B 18/14 Probes or electrodes therefor
• 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 2018/00005 Cooling or heating of the probe or tissue immediately surrounding the probe
• CPC Class Codes: A61B 2018/00053 Mechanical features of the instrument of device
• CPC Class Codes: A61B 2018/00291 using suction
• CPC Class Codes: A61B 2018/00642 with feedback, i.e. closed loop control
• CPC Class Codes: A61B 2018/00702 Power or energy
• CPC Class Codes: A61B 2018/00791 Temperature
• CPC Class Codes: A61B 2018/00875 Resistance or impedance
• CPC Class Codes: A61B 2018/126 bipolar
• CPC Class Codes: A61B 2018/1472 for use with liquid electrolyte, e.g. virtual electrodes
• CPC Class Codes: A61B 2218/002 Irrigation
• CPC Class Codes: A61B 2218/007 Aspiration

Abstract

A method and apparatus for creating a virtual electrode to ablate bodily tissue. The apparatus includes an outer tube, a first electrode, an inner tube and a second electrode. The outer tube is fluidly connected to a source of conductive fluid and defines a proximal end and a distal end. The distal end includes an opening for delivering conductive fluid from the outer tube. The first electrode is disposed at the distal end of the outer tube for applying a current to conductive fluid delivered from the outer tube. The inner tube is coaxially received within the outer tube and is connected to a source of conductive fluid. The inner tube defines a proximal end and a distal end, with the distal end forming an opening for delivering conductive fluid from the inner tube. Finally, the second electrode is disposed at the distal end of the inner tube for applying a current to conductive fluid delivered from the inner tube. With this configuration, upon final assembly, the distal end of the outer tube is axially spaced from the distal end of the inner tube such that the first electrode is spaced from the second electrode. As a result, a bi-polar virtual electrode can be established.

Claims

1. A method for treating a tissue comprising:

providing a suction apparatus for treating tissue, the suction apparatus comprising;

a first electrode spaced from a second electrode,

a first flow passage opening positioned to dispense electrically conductive fluid adjacent the first electrode,

a second flow passage opening positioned to dispense electrically conductive fluid adjacent the second electrode, and

a vacuum aperture positioned between the first and second electrodes;

positioning the first and second electrodes adjacent the tissue;

providing suction to the vacuum aperture to draw the tissue adjacent the aperture into contact with the apparatus;

dispensing an electrically conductive fluid from the first and second flow passage openings; and

providing an electric current to the first and second electrodes for treating the tissue.

2. The method of claim 1, wherein the electrically conductive fluid is provided from a fluid source.

3. The method of claim 1, wherein the electrically conductive fluid comprises an electrically conductive solution.

4. The method of claim 3, wherein the electrically conductive solution comprises saline.

5. The method of claim 1, wherein the electric current comprises radiofrequency alternating current provided from a radiofrequency generator.

6. The method of claim 1, wherein suction is provided from a vacuum source.

7. A method for ablating a tissue comprising:

providing an apparatus, the apparatus comprising a first electrode, a second electrode and a vacuum aperture positioned between the first and second electrodes;

altering a spacing between the vacuum aperture and at least one of the first and second electrodes;

positioning the first and second electrodes adjacent the tissue;

providing suction to the vacuum aperture to draw the tissue into contact with the apparatus; and

providing an electric current to the first and second electrodes for ablating the tissue.

8. The method of claim 7, wherein the apparatus further comprises:

a first tube, the first tube providing a first tube flow passage and a first tube flow passage opening, the first tube flow passage opening positioned adjacent the first electrode; and

a second tube, the second tube providing a second tube flow passage and a second tube flow passage opening, the second tube flow passage opening positioned adjacent the second electrode.

9. The method of claim 8, further comprising:

dispensing an electrically conductive fluid through the first and second tube flow passage openings.

10. The method of claim 9, and further wherein:

the first tube and the second tube are coaxially arranged; and

the distal end of the first tube is axially spaced from the distal end of the second tube.

11. The method of claim 9, wherein the electrically conductive fluid is provided from a fluid source.

12. The method of claim 9, wherein the electrically conductive fluid comprises an electrically conductive solution.

13. The method of claim 12, wherein the electrically conductive solution comprises saline.

14. The method of claim 7, wherein the electric current comprises radiofrequency alternating current provided from a radiofrequency generator.

15. The method of claim 7, wherein suction is provided from a vacuum source.

16. A method for ablating bodily tissue comprising:

providing an ablation system for ablating bodily tissue, the system comprising;

a vacuum source for providing suction,

a fluid source for delivering an electrically conductive fluid,

a radiofrequency generator for supplying an electric current,

a suction apparatus coupled to the vacuum source, the fluid source and the radiofrequency generator, the suction apparatus comprising;

a first electrode spaced from a second electrode,

a first flow passage opening positioned to deliver electrically conductive fluid from the fluid source adjacent the first electrode,

a second flow passage opening positioned to deliver electrically conductive fluid from the fluid source adjacent the second electrode, and

a vacuum aperture positioned between the first and second electrodes;

positioning the first and second electrodes adjacent the bodily tissue;

providing suction from the suction source to the vacuum aperture to draw into contact the bodily tissue adjacent the aperture;

delivering the electrically conductive fluid from the fluid source through the first and second flow passage openings; and

providing the electric current from the radiofrequency generator to the first and second electrodes for ablating the bodily tissue.

17. The method of claim 16, wherein the electrically conductive fluid comprises an electrically conductive solution.

18. The method of claim 17, wherein the electrically conductive solution comprises saline.

19. The method of claim 16, wherein:

a first bolus of electrically conductive fluid is delivered from the fluid source through the first flow passage opening; and

a second bolus of electrically conductive fluid is delivered from the fluid source through the second flow passage opening, the second bolus being spaced from the first bolus.

20. The method of claim 19, wherein the first and second boluses are delivered substantially simultaneously.