Electrosurgical instrument

Patent metadata

Field	Value
Publication number	US-9820809-B2
Application number	US-201414313156-A
Country	US
Kind code	B2
Filing date	Jun 24, 2014
Priority date	Jun 24, 2013
Publication date	Nov 21, 2017
Grant date	Nov 21, 2017

Abstract

An electrosurgical instrument is provided for the treatment of tissue, the instrument ( 3 ) including a shaft ( 14 ) and a tip portion including at least one electrode ( 16 ), located at the distal end of the shaft. A fluid impermeable sheath ( 25 ) covers at least a proportion of the shaft and extends to the tip portion where it terminates in a distal end portion ( 26 ). A metallic shroud ( 29 ) is provided, comprising an annular ring portion ( 30 ) and a rearwardly extending cylindrical portion ( 31 ). The ring portion ( 30 ) is connected to the tip portion, and the cylindrical portion ( 31 ) overlies the distal end portion ( 26 ) of the sheath ( 25 ) so as to prevent ingress of fluids at the distal end portion of the sheath.

First claim

The invention claimed is:

1. An electrosurgical instrument, including:
a) a shaft having a longitudinal axis defining a proximal and a distal direction,
b) a tip portion located at a distal end of the shaft, the tip portion including at least one active tissue treatment electrode,
c) a fluid impermeable sheath covering at least a portion of an outside of the shaft and extending to the tip portion where it terminates in a distal end portion, the fluid impermeable sheath forming an external fluid impermeable boundary over the portion of the outside of the shaft covered by the fluid impermeable sheath, and
d) a metallic shroud comprising an annular ring portion and a rearwardly extending cylindrical portion,
the annular ring portion being connected to the tip portion, and the rearwardly extending cylindrical portion overlying the distal end portion of the fluid impermeable sheath so as to prevent ingress of fluids at the distal end portion of the fluid impermeable sheath, a cross-sectional thickness of the annular ring portion being greater than a cross-sectional thickness of the rearwardly extending cylindrical portion, thereby allowing clearance for the distal end portion of the fluid impermeable sheath to be received under the rearwardly extending cylindrical portion of the metallic shroud so that the rearwardly extending cylindrical portion overlies the distal end portion so as to prevent the ingress of the fluids at the distal end portion.

2. The electrosurgical instrument according to claim 1 , wherein the annular ring portion is connected to the tip portion at a location distal of a point where the fluid impermeable sheath terminates in a distal end portion.

3. The electrosurgical instrument according to claim 1 , wherein the annular ring portion is connected to the tip portion by a process involving heating the ring portion.

4. The electrosurgical instrument according to claim 3 , wherein the annular ring portion is welded to the tip portion.

5. The electrosurgical instrument according to claim 4 , wherein the annular ring portion is laser welded to the tip portion.

6. The electrosurgical instrument according to claim 3 , wherein the fluid impermeable sheath is melted in a region of the rearwardly extending cylindrical portion of the metallic shroud so as to be sealed against the rearwardly extending cylindrical portion.

7. The electrosurgical instrument according to claim 1 , wherein the tip portion includes a bipolar electrode assembly comprising the at least one active tissue treatment electrode and at least one return electrode.

8. The electrosurgical instrument according to claim 7 , wherein the annular ring portion is connected to the return electrode.

9. The electrosurgical instrument according to claim 1 , wherein the electrosurgical instrument is an endoscopic surgical instrument.

10. The electrosurgical instrument according to claim 1 , wherein the at least one active tissue treatment electrode comprising a hemispherical end face and a cylindrical side face.

11. The electrosurgical instrument according to claim 10 , wherein the hemispherical end face is provided with a single aperture located at a center of the hemispherical end face, and wherein the cylindrical side face is provided with a plurality of apertures spaced at equal distances around a circumference of the cylindrical side face.

12. The electrosurgical instrument according to claim 10 , wherein the at least one active tissue treatment electrode is located on a ceramic component and held in place by a split ring retainer which is laser welded in place.

13. The electrosurgical instrument according to claim 12 , wherein the at least one active tissue treatment electrode and the ceramic component are both hollow so as to form a suction lumen, and also to accommodate a lead for supplying radio frequency (RF) energy to the at least one active tissue treatment electrode.

14. A method of manufacturing the electrosurgical instrument according to claim 1 , the method comprising the steps of:
a) providing the shaft, the tip portion including the at least one active tissue treatment electrode, the fluid impermeable sheath, and the metallic shroud comprising the annular ring portion and the rearwardly extending cylindrical portion,
b) securing the tip portion at the distal end of the shaft,
c) applying the fluid impermeable sheath to the shaft such that it covers at least a proportion of the shaft and extends to the tip portion where it terminates in a distal end portion,
d) applying the metallic shroud such that the cylindrical portion covers the distal end portion of the sheath, and
e) welding the annular ring portion to the tip portion such that it is secured thereto, in such a way that heat from the welding process also heats the cylindrical portion and melts the fluid impermeable sheath in the location thereof, sealing the fluid impermeable sheath to the cylindrical portion.

Assignees

• Gyrus Medical Ltd

Inventors

• Hoodless Richard John
• Keogh Richard John

Classifications

• A61B2018/1472

  for use with liquid electrolyte, e.g. virtual electrodes · CPC title

• A61B2017/00526

  Methods of manufacturing · CPC title

• Y10T29/49117

  Conductor or circuit manufacturing · CPC title

• B23P17/00

  Metal-working operations, not covered by a single other subclass or another group in this subclass · CPC title

• A61B2018/162

  located on the probe body · CPC title