Skin electrode

• US 6,845,272 B1
• Filed: 05/25/1999
• Issued: 01/18/2005
• Est. Priority Date: 05/25/1999
• Status: Expired due to Fees

• Current Assignee: Medicotest A/S
• Original Assignee: Medicotest A/S
• Inventors: Nielsen, Brian, Thomsen, Steen, Gothjælpsen, Laila Busk
• Primary Examiner(s): EVANISKO, GEORGE ROBERT
• Application Number:
  US09/979,270
• Time in Patent Office: 2,065 Days
• Field of Search: 607/153, 607/397, 607/115, 607/142, 607/149, 600/372, 600/382, 600/386, 600/391, 600/392, 600/395, 600/396, 600/397
• US Class Current: 607/153
• CPC Class Codes: A61B 5/259 using conductive adhesive means, e.g. gels
• CPC Class Codes: A61B 5/28 for electrocardiography [ECG]
• CPC Class Codes: A61N 1/0452 Specially adapted for transcutaneous muscle stimulation [TMS]
• CPC Class Codes: A61N 1/0456 Specially adapted for transcutaneous electrical nerve stimulation [TENS]
• CPC Class Codes: A61N 1/046 Specially adapted for shock therapy, e.g. defibrillation
• CPC Class Codes: A61N 1/048 Electrodes characterised by a specific connection between lead and electrode
• CPC Class Codes: A61N 1/0496 characterised by using specific chemical compositions, e.g. hydrogel compositions, adhesives

Abstract

An electrode for establishing electrical contact with the skin is disclosed, said electrode having a low impedance and comprising an electrically conductive metallic layer (4) and an electrically conductive gel (12) attached to said metallic layer, wherein the pH of the electrically conductive gel (12) is chosen so as to provide a corrosion of the metallic layer (4).

Claims

1. A defibrillation or electrocardiogram electrode for establishing electrical contact with the skin, said electrode comprising an electrically conductive metallic layer having a high sensitivity to acid and an electrically conductive gel attached to said metallic layer, thereby providing an interface between said gel and said metallic layer, wherein said electrically conductive gel has a pH between 1 and 3 so as to provide corrosion of said metallic layer, wherein a high concentration of ions are etched from said metallic layer, generating a concentration of metallic ions at the interface between the gel and said metallic layer, said concentration of metallic ions contributing to the availability of current carriers when a current is impressed on the electrode, and wherein said defibrillation or electrocardiogram electrode is adapted for administering an electric shock to a patient or monitoring the electrocardiogram of said patient when connected to a defibrillator or an electrocardiogram apparatus.

2. An electrode according to claim 1, wherein the electrically conductive metallic layer is selected from the group consisting of tin, aluminium, zinc and lead.

3. An electrode according to claim 2, wherein said electrically conductive metallic layer comprises tin.

4. An electrode according to claim 3, wherein said electrically conductive metallic layer consists of tin having a purity of 99% by weight or more.

5. An electrode according to claim 1, wherein said electrically conductive gel is a hydrogel.

6. An electrode according to claim 1, wherein said electrically conductive gel comprises a polymer containing ionizable groups in a polymer structure.

7. An electrode according to claim 6, wherein said electrically conductive gel comprises a polymer containing acid groups.

8. An electrode according to claim 7, wherein said electrically conductive gel comprises a copolymer of acrylic acid or a homopolymer of acrylic acid.

9. An electrode according to claim 1, wherein said electrically conductive gel comprises an ionized salt homogeneously distributed therein.

10. An electrode according to claim 9, wherein said salt is selected from the group consisting of KCl, KBr, NaCl, AgCl and SnCl₂.

11. An electrode according to claim 1, wherein said electrically conductive metallic layer on the face opposite the face attached to the electrically conductive gel is covered by an electrically insulating cover.

12. An electrode according to claim 1, wherein said electrically conductive metallic layer is connected to a point adapted to mate with a corresponding portion of a connector.

13. An electrode according to claim 1, wherein said electrically conductive gel on the face opposite the metallic layer is covered by one or more electrically conductive gel layers.

14. An electrode according to claim 13, wherein said one or more electrically conductive gel layers has a pH of 5-9.

15. An electrode according to claim 1, wherein said electrically conductive gel contains above 50 percent by weight of water.

16. An electrode according to claim 1, wherein said electrically conductive gel contains above 70 percent by weight of water.

18. A method of improving the shelf-life of the electrode according claim 1 or and 17 wherein, during storage, the metallic layer is connected to a sacrificial electrode.

17. A defibrillation and electrocardiogram electrode for establishing electrical contact with the skin, said electrode comprising an electrically conductive metallic layer having a high sensitivity to acid and an electrically conductive gel attached to said metallic layer, thereby providing an interface between said gel and said metallic layer, wherein said electrically conductive gel has a pH between 1 and 3 so as to provide corrosion of said metallic layer, wherein a high concentration of ions are etched from said metallic layer, generating a concentration of metallic ions at the interface between the gel and said metallic layer, said concentration of metallic ions contributing to the availability of current carriers when a current is impressed on the electrode, wherein said electrode is adapted to be a combined defibrillation and electrocardiogram electrode, and wherein said combined defibrillation and electrocardiogram electrode is adapted for administering an electric shock to a patient and monitoring the electrocardiogram of said patient when connected to a defibrillator and an electrocardiogram apparatus.