Biomedical electrode providing early detection of accidental detachment

• US 5,797,902 A
• Filed: 05/10/1996
• Issued: 08/25/1998
• Est. Priority Date: 05/10/1996
• Status: Expired due to Term

• Current Assignee: Minnesota Mining and Manufacturing Co (3M Company)
• Original Assignee: Minnesota Mining and Manufacturing Co (3M Company)
• Inventors: Netherly, Samuel G.
• Primary Examiner(s): Cohen, Lee S.
• Application Number:
  US08/644,799
• Time in Patent Office: 837 Days
• Field of Search: 606/32, 606/35, 607/142, 607/149, 607/152, 607/157
• US Class Current: 606/32
• CPC Class Codes: A61B 18/16 Indifferent or passive electrodes for grounding
• CPC Class Codes: A61N 1/05 for implantation or insertion into the body, e.g. heart electrode A61N1/06 takes precedence

Abstract

A biomedical electrode is disclosed, having a geometry of conductive plates along a longitudinal axis of the electrode such that interior edge(s) of the plate(s) adjoining the axis are curvilinear or otherwise non-parallel to the axis. The geometry permits the electrode to register an earlier detection of a CQM alarm condition if a portion of the electrode unpeels from contact with the body of a mammalian patient before the extent of unpeeling would otherwise cause a CQM alarm condition established by and issued from an electrosurgical generator.

Claims

1. A biomedical electrode, comprising:

an electrically non-conductive backing;

two conductive plates required for Contact Quality Monitoring circuitry separated from each other along a longitudinal axis of the backing, each conductive plate contacting the electrically non-conductive backing, and each conductive dilate having a curvilinear interior edge adjoining the longitudinal axis which edge is also symmetrical about an axis orthogonal to the longitudinal exit; and

optionally,

a field of conductive adhesive in contact with both the conductive plates, wherein

the minimum distance separating the conductive plates along the longitudinal axis at a first point distal from an outside edge of the biomedical electrode intersecting the longitudinal axis is substantially greater than the minimum distance separating the conductive plates at a second point more proximal to the outside edge of the biomedical electrode.

2. The biomedical electrode according to claim 1, further comprising a field of lossy dielectric material between the conductor plates and a surface of the electrode that can contact a body of a patient.

3. The biomedical electrode according to claim 1, wherein the conductive plates have a body contacting portion and wherein

the ratio between the minimum distance separating the conductive plates along the longitudinal axis at a point away from the outside edge of the body contact portion and the minimum distance separating the conductive plates at a point near the outside edge of the body contact portion is greater than about 2:

1.

4. The biomedical electrode, according to claim 3, wherein

the ratio between the minimum distance separating the conductive plates at a point away from the outside edge of the body contact portion and the minimum distance separating the conductive plates at a point near the outside edge of the body contact portion is between about 3:

1 and 15;

1.

5. The biomedical electrode, according to claim 4, wherein

the ratio between the minimum distance separating the conductive plates at a point away from the outside edge of the body contact portion and the minimum distance separating the conductive plates at a point near the outside edge of the body contact portion is between about 4:

1 and 10;

1.

6. An electrosurgical CQM circuit, comprising:

(a) an electrosurgical generator having CQM circuit;

(b) a biomedical electrode; and

(c) electrical connections between the generator and the electrode,

wherein the biomedical electrode, comprises an electrically nonconductive backing;

two conductive plates required for Contact Quality Monitoring circuitry separated from each other along a longitudinal axis of the backing, each conductive plate contacting the electrically non-conductive backing and each conductive plate having a curvilinear interior edge adjoining the longitudinal axis which edgei s also symmetrical about an axis orthogonal to the longitudinal axis; and

optionally,

a field of conductive adhesive in contact with both the conductive plates, wherein

the minimum distance separating the conductive plates along the longitudinal axis at a first point distal from an outside edge of the biomedical electrode intersecting the longitudinal axis is substantially greater than the minimum distance separating the conductive plates at a second point more proximal to the outside edge of the biomedical electrode.

7. An electrosurgical system, comprising:

(a) an electrosurgical generator having CQM circuitry;

(b) a biomedical electrode;

(c) an electrosurgical pencil electrically connected to the generator; and

(d) electrical connections between the generator and the electrode,

wherein the biomedical electrodes comprises an electrically non-conductive backing;

two conductive plates required for Contact Quality Monitoring circuitry separated from each other along a longitudinal axis of the backing, each conductive plate contacting the electrically non-conductive backing, and each conductive plate having a curvilinear interior edge adjoining the longitudinal axis which edge is also symmetrical about an axis orthogonal to the longitude axis; and

optionally,

a field of conductive adhesive in contact with both the conductive plates, wherein

the minimum distance separating the conductive plates along the longitudinal axis at a first point distal from an outside edge of the biomedical electrode intersecting the longitudinal axis is substantially greater than the minimum distance separating the conductive plates at a second point more proximal to the outside edge of the biomedical electrode.

8. A method of early detection of an electrosurgical CQM alarm condition, comprising the steps of:

(a) contacting a biomedical electrode to the body of a mammalian patient;

(b) sounding an alarm when a portion of the biomedical electrode separates from contact with the body of the patient,

wherein the portion of the biomedical electrode separated lies along a longitudinal axis of the biomedical electrode,

wherein the biomedical electrode comprises an electrically non-conductive backing and two conductive plates;

wherein the two conductive plates require for Contact Quality Monitoring circuitry are separated from each other alone the longitudinal axis, each conductive plate contacting the electrically non-conductive backing, and each conductive plate having a curvilinear interior edge adjoining longitudinal axis which edge is also symmetrical about an axis orthogonal to the longitudinal axis and

wherein a minimum distance separating the conductive plates along the longitudinal axis at a first point distal from an outside edge of the biomedical electrode intersecting the longitudinal axis is substantially greater than the minimum distance separating the conductive plates at a second point more proximal to the outside edge of the biomedical electrode.