BIPOLAR CANNULA FOR USE WITH AN ELECTRODE ASSEMBLY HAVING A SEPARATE SUPPLY ELECTRODE

• US 20110160723A1
• Filed: 03/08/2011
• Published: 06/30/2011
• Est. Priority Date: 04/29/2005
• Status: Active Grant

• Current Assignee: Stryker Corporation
• Original Assignee: Stryker Corporation
• Inventors: Cramlet, Eland, Fickes, Nicole, Staats, Andy, Staunton, Douglas Alan, Gamhewage, Chamara, Tullis, Philip James
• Granted Patent: US 8,852,182 B2
• Time in Patent Office: Days
• US Class Current: 606/41
• CPC Class Codes: A61B 18/1477 Needle-like probes
• CPC Class Codes: A61B 2017/00212 using remote controls
• CPC Class Codes: A61B 2017/00867 shape memory effect for prostheses A61F2210/0014
• CPC Class Codes: A61B 2018/00434 Neural system
• CPC Class Codes: A61B 2018/0044 Spinal cord
• CPC Class Codes: A61B 2018/00821 measured by a thermocouple
• CPC Class Codes: C08L 2201/12 Shape memory

Abstract

An electrosurgical system preferably used for denervation procedures of nerve tissue has a control unit and a pluggable electrode assembly. The electrode assembly has a preferably disposable cannula and a preservable supply electrode assembly. The cannula has a tubular body that projects axially from a preferably pointed distal end for piercing tissue to a proximal end engaged to a first coupling assembly of the cannula. The body carries a first contact exposed directly to the nerve tissue and connected electrically to a terminal of the first coupling assembly. The supply electrode assembly has a second coupling assembly and a supply electrode that projects axially and removably into a through-bore of the body when the tool is in an operating state. The second coupling assembly carries a terminal that abuts the first coupling assembly when the coupling assemblies are mated. Preferably the supply electrode carries a temperature sensor for temperature measurement of the targeted tissue and processing by the control unit. Preferably, the electrode assembly also includes a stylet having a rod that fits into the through-bore of the body when the supply electrode assembly is removed and the tool is in a tissue penetrating state.

Claims

1. An electrode assembly comprising:

a cannula having;

a first coupling assembly with a hub; and

an elongated tubular body having a proximal end mounted to said hub of said first coupling assembly and projecting outward to a distal end, first and second spaced apart and oppositely charged contacts disposed adjacent to said distal end, and a first conductive terminal seated in said hub and electrically connected to said second active contact; and

a supply electrode assembly having;

a supply electrode having spaced apart proximal and distal ends;

a second coupling assembly attached to said proximal end of said supply electrode; and

a second conductive terminal attached to said second coupling assembly;

said supply electrode is dimensioned to be slidably inserted in said elongated tubular body so as to be positioned to electrically contact said first active contact;

said first and second coupling assemblies are configured to releasably interlock; and

said first and second conductive terminals are collectively positioned so that when said coupling assemblies interlock, said conductive terminals abut.

2. The electrode assembly set forth in claim 1 wherein said elongated tubular body includes an inner tube having said first active contact with a through-bore defined by and extending co-axially with said inner tube.

3. The electrode assembly set forth in claim 2 wherein said supply electrode is disposed at least in-part in said through-bore.

4. The electrode assembly set forth in claim 2 further comprising an outer cylindrical shell of said supply electrode being in electrical contact with an inner cylindrical wall of said inner tube.

5. The electrode assembly set forth in claim 4 wherein a clearance between said outer cylindrical shell and said inner cylindrical wall is less than 0.025 mm.

6. The electrode assembly set forth in claim 2 wherein said through-bore communicates through said distal end of said elongated tubular body.

7. The electrode assembly set forth in claim 1 wherein said distal end of said supply electrode is generally axially aligned to said distal end of said elongated tubular body when said first and second coupling assemblies are interlocked.

8. The electrode assembly set forth in claim 7 further comprising a temperature sensor orientated in said supply electrode near said distal end of said supply electrode for measuring tissue temperature.

9. The electrode assembly set forth in claim 7 further comprising first and second stops carried by said respective first and second coupling assemblies for maintaining consistent axial alignment of said distal end of said supply electrode with said distal end of said elongated tubular body.

10. The electrode assembly as set forth in claim 1 wherein said supply electrode is formed from a nickel titanium alloy.

11. The electrode assembly as set forth in claim 1 wherein said first coupling assembly includes an alcove formed in said cannula hub and wherein said second coupling assembly of said supply electrode includes a housing from which said supply electrode extends and a tab that extends from said housing, said tab dimensioned to seat in said hub alcove.

12. The electrode assembly as set forth in claim 11 wherein said first conductive terminal is seated in said cannula hub alcove and wherein said second conductive terminal is mounted in said housing so that when said tab seats in said alcove, said second conductive terminal abuts said first conductive terminal.

13. The electrode assembly as set forth in claim 1 wherein said cannula includes a memory that contains data describing the characteristics of said cannula and wherein said supply electrode assembly includes a contactor positioned to mate with said cannula memory when said coupling assemblies interlock.

14. An electrode assembly comprising:

a cannula having;

a first coupling assembly having a first circumferential indexing feature; and

an elongated tubular body having a proximal end mounted to said first coupling assembly and projecting outward to a distal end, first and second spaced apart and oppositely charged contacts disposed adjacent to said distal end, and a first conductive terminal seated in said first coupling assembly and electrically connected to said second contact; and

a supply electrode assembly having;

a supply electrode having spaced apart proximal and distal ends;

a second coupling assembly attached to said proximal end of said supply electrode and having a second circumferential indexing feature; and

a second conductive terminal attached to said second coupling feature;

said supply electrode is dimensioned to be slidably inserted in said elongated tubular body so as to be positioned to electrically contact said first active contact; and

said first and second coupling assemblies are configured to releasably interlock such that said first and second circumferentially indexing features mate to prevent circumferential misalignment.

15. The electrode assembly set forth in claim 14 wherein said elongated tubular body includes an inner tube having said first active contact with a through-bore defined by and extending co-axially with said inner tube.

16. The electrode assembly set forth in claim 15 further comprising an outer cylindrical shell of said supply electrode being in electrical contact with an inner cylindrical wall of said inner tube.

17. The electrode assembly set forth in claim 16 wherein a clearance between said outer cylindrical shell and said inner cylindrical wall is less than 0.025 mm.

18. The electrode assembly set forth in claim 14 further comprising a temperature sensor orientated in said supply electrode near said distal end of said supply electrode for measuring tissue temperature.

19. An electrode assembly comprising:

a cannula having;

a first coupling assembly with a hub having a proximal end and defining a bore; and

an elongated tubular body having a proximal end mounted to said hub of said first coupling assembly and projecting outward to a distal end, first and second spaced apart and oppositely charged contacts disposed adjacent to said distal end, and a first conductive terminal seated in said hub and electrically connected to said second contact; and

a supply electrode assembly having;

a supply electrode having spaced apart proximal and distal ends;

a second coupling assembly attached to said proximal end of said supply electrode; and

a second conductive terminal attached to said second coupling assembly;

said elongated tubular body defines a through-bore open to said hub bore and dimensioned to receive said supply electrode;

said hub bore decreases in diameter from said proximal end toward said through-bore for facilitating insertion of said supply electrode into said through-bore when mating said supply electrode assembly with said cannula; and

said hub has a collar with a cross sectional area less than that of said proximal end and said collar extends rearwardly from said hub proximal end.