Electrosurgical working end for controlled energy delivery

• US 7,070,597 B2
• Filed: 08/19/2003
• Issued: 07/04/2006
• Est. Priority Date: 10/18/2001
• Status: Expired due to Term

• Current Assignee: Ethicon Endo-Surgery, Inc. (Johnson & Johnson)
• Original Assignee: SurgRx, Inc. (Johnson & Johnson)
• Inventors: Shadduck, John H., Truckai, Csaba
• Primary Examiner(s): Cohen, Lee
• Assistant Examiner(s): ROANE, AARON F
• Application Number:
  US10/643,787
• Publication Number:
  US 20040215185A1
• Time in Patent Office: 1,050 Days
• Field of Search: 600/373, 606/32, 606/37, 606/38, 606/41, 606/42, 607/115
• US Class Current: 606/41
• CPC Class Codes: A61B 18/1442 Probes having pivoting end effectors, e.g. forceps
• CPC Class Codes: A61B 2018/00077 high, i.e. electrically conducting
• CPC Class Codes: A61B 2018/00083 low, i.e. electrically insulating
• CPC Class Codes: A61B 2018/00148 with metal
• CPC Class Codes: A61B 2018/0063 Sealing

Abstract

An electrosurgical working end for automatic modulation of active Rf density in a targeted tissue volume. The working end of the probe of the present invention defines a tissue-engagement surface of an elastomeric material with conductive elements that extend therethrough. In one embodiment, the expansion of the elastomeric material can de-couple the conductive elements from an interior electrode based temperature to modulate current flow. In another embodiment, the elastomeric material can couple and de-couple the conductive elements from an interior electrode based engagement pressure to modulate current flow.

Claims

1. An electrosurgical probe for delivering energy to tissue, the probe comprising:

a body having a working end comprising an interior conductor covered by a surface layer comprising a substantially insulative material;

at least one conductive element extending though the surface layer, wherein the conductive element has an exposed first end and an interior second end disposed proximate to the interior conductor;

wherein the surface layer has a thermal expansion coefficient configured such that the surface layer at a first lower temperature maintains said second end of the conductive element in contact with the interior conductor, and at a second higher temperature moves said second end away from contact with the interior conductor.

2. The working end of claim 1, further comprising an electrical energy source operatively coupled to said interior conductor.

3. The working end of claim 1, further comprising a return electrode carried about an exterior of the probe and spaced apart from the surface layer.

4. The working end of claim 3, further comprising a resistor disposed between the interior conductor and the return electrode.

5. The working end of claim 1, wherein the surface layer comprises a resilient material.

6. The working end of claim 1, wherein the surface layer comprises a polymer.

7. The working end of claim 1, wherein the surface layer comprises a polymer having a positive temperature coefficient.

8. The working end of claim 7, wherein the surface layer is configured to minimize tissue dehydration from Rf energy delivery.

9. The working end of claim 7, wherein the surface layer is configured to utilize Rf energy to actively and passively heat tissue.

10. The working end of claim 9, wherein the surface layer comprises a resistive material configured to be heated by Rf current.

11. The working end of claim 9, wherein the surface layer and the interior electrode have a thermal mass configured to passively conduct heat to tissue to maintain a tissue volume at a selected temperature.

12. The working end of claim 1, further comprising a resistor disposed proximal to the surface layer.

13. The working end of claim 1, wherein the surface layer comprises a ceramic.

14. The working end of claim 1, wherein the surface layer extends around a perimeter of the probe exterior.

15. The working end of claim 1, wherein the surface layer has an open cell structure.

16. The working end of claim 1, wherein the surface layer has a closed cell structure.

17. A working end of a surgical probe for pressure-controlled Rf energy application to tissue, the working end comprising:

an interior electrode having an elastomeric surface layer;

at least one conductive element extending through the elastomeric surface layer, the element having a first exposed end and a second end disposed proximate to the interior electrode;

the second end being movable into or away from electrical contact with the interior electrode responsive to a selected pressure on the surface layer.

18. The working end of claim 17, further comprising an Rf energy source operatively coupled to said interior electrode.

19. The working end of claim 17, further comprising a return electrode carried about an exterior of the probe.

20. The working end of claim 19, further comprising a resistor disposed intermediate the interior electrode and the return electrode.

21. The working end of claim 17, wherein the surface layer comprises a non-conductive polymer.

22. The working end of claim 17, wherein the surface layer comprises a polymer having a positive temperature coefficient.

23. The working end of claim 17, wherein the surface layer comprises silicone doped with a conductive composition.

24. The working end of claim 17, wherein the surface layer extends around a perimeter of the probe exterior.