Systems and methods systems related to electrosurgical wands with screen electrodes

Patent metadata

Field	Value
Publication number	US-9526556-B2
Application number	US-201414192978-A
Country	US
Kind code	B2
Filing date	Feb 28, 2014
Priority date	Feb 28, 2014
Publication date	Dec 27, 2016
Grant date	Dec 27, 2016

Abstract

An electrosurgical wand for treating tissue at a target site within or on a patient's body is described, having an elongate shaft with a handle and a distal end portion. The distal end portion has an active electrode, an insulative spacer body and a return electrode; the active electrode supported by the insulative spacer body and spaced away from the return electrode. The active electrode has both lateral and medial edge surfaces. The insulative spacer body has an aspiration cavity fluidly connected with an aspiration lumen, and at least one tapered aperture extending beyond at least one of the electrode medial edge surfaces and directed to the aspiration cavity.

First claim

What is claimed is:

1. An electrosurgical wand for treating tissue at a target site within or on a patient's body comprising:
an elongate shaft having a handle end and a distal end portion, the distal end portion comprising an active electrode, an insulative spacer body and a return electrode, wherein the active electrode is supported on the insulative spacer body and is spaced away from the return electrode;
wherein the active electrode defines a peripheral edge surface;
wherein the insulative spacer body defines an aspiration cavity fluidly connected with an aspiration lumen and terminating with a cavity aperture having a perimeter, wherein the active electrode partially cover the cavity aperture so as to define at least one aspiration aperture having an aspiration aperture perimeter that is defined by the cavity aperture perimeter and the active electrode peripheral edge surface.

2. The electrosurgical wand of claim 1 wherein the peripheral edge surface defines at least one active electrode lateral edge surface portion free of any asperities and spaced away from the cavity aperture.

3. The electrosurgical wand of claim 1 wherein the active electrode further comprises an electrode aperture in fluid communication with the aspiration cavity and spaced away from the active electrode peripheral edge surface.

4. The electrosurgical wand of claim 1 , wherein the at least one aspiration aperture comprises at least two aspiration apertures each having a perimeter defined by the active electrode peripheral edge surface and the cavity aperture perimeter.

5. The electrosurgical wand of claim 4 wherein the at least two aspiration apertures comprise a first and second aspiration aperture, the first aspiration aperture smaller than the second aspiration aperture.

6. The electrosurgical wand of claim 5 wherein the first aspiration aperture has a perimeter defined by a portion of the peripheral edge surface having at least one internal cusp with a first depth and the second aspiration aperture has a perimeter defined by a portion of the peripheral edge surface having at least one internal cusp with a second depth and wherein the first cusp depth is significantly smaller than the second cusp depth and wherein the cusps are configured to create an internal point of higher current density and preferential vapor layer formation.

7. The electrosurgical wand of claim 1 wherein the peripheral edge surface further comprises at least one internal cusp, configured to create a point of high current density for preferential vapor layer formation.

8. The electrosurgical wand of claim 7 wherein the at least one internal cusp is defined by an intersection between two adjacent curved portions, the intersection characterized by an internal pointed feature.

9. The electrosurgical wand of claim 1 further comprising at least one securing wire of conductive material, electrically coupled to and mechanically secured to a tissue contacting surface of the active electrode and wherein the at least one securing wire is disposed along a path defined by at least one active electrode wire aperture, at least one spacer body wire conduit and the elongate shaft and wherein the at least one securing wire is in electrical communication with a high frequency energy source.

10. The electrosurgical wand of claim 1 wherein the aspiration cavity is characterized by an elongate funnel shape so that the cavity aperture defines a first dimension and second dimension that is less than the first dimension.

11. The electrosurgical wand of claim 10 wherein the aspiration cavity tapers so as to define a maximum gap within the aspiration cavity, the gap configured so as to trap any larger tissue fragments within the aspiration cavity so that the tissue fragments are further ablated by a portion of the active electrode before allowing the fragments to pass into the aspiration lumen.

12. The electrosurgical wand of claim 1 wherein the aspiration cavity has a tapered surface.

13. An electrosurgical wand for treating tissue at a target site within or on a patient's body comprising:
an elongate shaft having a handle end and a distal end portion, the distal end portion comprising an active electrode, an insulative spacer body and a return electrode, wherein the active electrode is disposed on a first surface of the insulative spacer body and is spaced away from the return electrode;
wherein the active electrode comprises an outer edge surface defining first and second lateral and medial edge surface portions;
wherein the insulative spacer body defines an aspiration cavity fluidly connected with an aspiration lumen and at least one aspiration aperture, the at least one aspiration aperture having a perimeter at least partially defined by at least one of the medial edge surface portions.

14. The electrosurgical wand of claim 13 , the at least one aspiration aperture comprising a first and second aspiration aperture, the first aspiration aperture having a perimeter at least partially defined by the first medial edge portion and the second aspiration aperture having a perimeter at least partially defined by the second medial edge surface portion.

15. The electrosurgical wand of claim 14 wherein the first and second medial edge surface portions of the active electrode each further comprise at least one internal cusp, wherein at least one internal cusp is configured so as to create a preferential point of vapor layer formation, and wherein the at least one internal cusp is disposed along at least one of the first and second aspiration aperture perimeters.

16. The electrosurgical wand of claim 14 wherein the first aspiration aperture extends a first distance beyond the first medial edge surface portion and the second aspiration aperture extends a second distance beyond the second medial edge surface portion of the active electrode and wherein the first distance is smaller than the second distance.

17. The electrosurgical wand of claim 14 wherein the first medial edge surface portion of the active electrode has at least one internal cusp with a first depth and the second medial edge surface portion of the active electrode has at least one internal cusp with a second depth and wherein the first cusp depth is significantly smaller than the second cusp depth.

18. The electrosurgical wand of claim 13 wherein the aspiration cavity is characterized by an elongate funnel shape.

19. An electrosurgical wand for treating tissue at a target site within or on a patient's body comprising:
an elongate shaft defining a handle end and a distal end portion, the distal end portion comprising an active electrode, an insulative spacer body and a return electrode, wherein the active electrode is disposed on a distal surface of the insulative spacer body and is spaced away from the return electrode;
wherein the active electrode defines a peripheral edge surface defining distal and proximal edge surfaces;
wherein the insulative spacer body defines an aspiration cavity fluidly connected with an aspiration lumen and configured to aspirate fluid and plasma by-products therethrough, the aspiration cavity terminating on the distal surface of the spacer body with at least one cavity aperture, and wherein the active electrode covers a portion of the cavity aperture so as to define at least one aspiration aperture, the at least one aspiration aperture having a perimeter lying on a plane defined by the spacer body distal surface and defined by the active electrode peripheral edge surface and a perimeter of the cavity aperture.

Assignees

• Arthrocare Corp

Inventors

• Goode Johnson E
• Bieberich Mark
• Tetzlaff Philip M
• Woloszko Jean

Classifications

• A61B2218/007

  Aspiration · CPC title

• A61B18/14 Primary

  Probes or electrodes therefor · CPC title

• A61B2018/1405

  Electrodes having a specific shape · CPC title

• A61B18/042 Primary

  using additional gas becoming plasma · CPC title

• A61B2018/162

  located on the probe body · CPC title