Electrosurgical devices having sesquipolar electrode structures incorporated therein

• US 4,043,342 A
• Filed: 02/26/1976
• Issued: 08/23/1977
• Est. Priority Date: 08/28/1974
• Status: Expired due to Term

• Current Assignee: Valleylab Inc. (Medtronic Plc)
• Original Assignee: Valleylab Inc. (Medtronic Plc)
• Inventors: Morrison, Charles F. Jr.
• Primary Examiner(s): Michell, Robert W.
• Assistant Examiner(s): Cohen, Lee S.
• Application Number:
  US05/661,555
• Time in Patent Office: 544 Days
• Field of Search: 128/303.13-303.18, 128/404, 128/405
• US Class Current: 606/48
• CPC Class Codes: A61B 18/1402 Probes for open surgery
• CPC Class Codes: A61B 18/1815 using microwaves
• CPC Class Codes: A61B 2018/1475 Electrodes retractable in or deployable from a housing
• CPC Class Codes: A61N 1/04 Electrodes electrosurgical electrodes A61B18/14

Abstract

An electrosurgical device adapted for connection to an electrical generator having active and return output terminals, the device being used to cut, coagulate, or otherwise treat organic tissue or the like, the device comprising: an insulative support connectors; an active electrode responsive to the active output terminal and a return electrode responsive to the return output terminal, the electrodes being supported by the electrode support connectors, the return electrode being symmetrically disposed completely about the active electrode, the active electrode extending as far as or beyond the distal end of the return electrode, both the electrodes being adapted for electrical connection to the tissue, the ratio of the return electrode area adapted to electrically connect to the tissue to the active electrode area adapted to electrically connect to the tissue being in the range of approximately 2 to 200; and connectors for connecting the active electrode to the active output terminal and the return electrode to the return output terminal. Embodiments are also disclosed where the active electrode is spring biased with respect to the return electrode and vice versa.

Claims

1. An electrosurgical device adapted for connection to an electrical generator having active and return output terminals, said device being used to cut, coagulate, or otherwise treat organic tissue or the like, said device comprising:

an insulative support means;

an active electrode having a distal end and being responsive to said active output terminal and a return electrode having a distal end and being responsive to said return output terminal, said electrodes being supported by said electrode support means, means for maintaining a fixed spacing between the active electrode and the return electrode, said return electrode being electrically insulated from and symmetrically disposed completely about said active electrode, said active electrode extending at least as far as the distal end of said return electrode, both said electrodes being adapted for electrical connection to said tissue, the ratio of the return electrode area adapted to electrically connect to said tissue to the active electrode area adapted to electrically connect to said tissue being in the range of approximately 2 to 200;

means for connecting said active electrode to said active output terminal and said return electrode to said return output terminal; and

means for so biasing said return electrode with respect to the active electrode that the return electrode is normally disposed at a first position where the return electrode extends as far as the distal end of the active electrode and a retracted position where the return electrode is retracted from the distal end of the active electrode in response to said active electrode being inserted into said tissue.

2. A method of treating tissue by fulguration with an electrosurgical device, said device being connected to an electrical generator having active and return output terminals, said device including an insulative support means;

an active electrode having a distal end and being responsive to said active output terminal and a return electrode having a distal end and being responsive to said return output terminal, said electrodes being supported by said electrode support means, means for maintaining a fixed spacing between the active electrode and the return electrode, said return electrode being electrically insulated from and symmetrically disposed completely about said active electrode, the distal end of said active electrode extending at least as far as the distal end of said return electrode, both said electrodes being adapted for electrical connection to said tissue, the ratio of the return electrode area adapted to electrically connect to said tissue to the active electrode area adapted to electrically connect to said tissue being in the range of approximately 2 to 200;

means for connecting said active electrode to said active output terminal and said return electrode to said return output terminal, and means for so biasing said return electrode with respect to the active electrode that the return electrode is normally disposed at a first position where the return electrode extends as far as the distal end of the active electrode and a retracted position where the return electrode is retracted from the distal end of the active electrode in response to said active electrode being inserted into said tissue, said method comprising the steps of

applying electrical energy from said generator to said active and return electrodes;

initially contacting said tissue, subsequent to said applying step, with said return electrode so that said fulguration initially occurs from said active electrode.