Electrode systems, devices and methods

• US 9,955,881 B2
• Filed: 03/04/2014
• Issued: 05/01/2018
• Est. Priority Date: 06/28/2007
• Status: Active Grant

• Current Assignee: University of Pittsburgh of The Commonwealth System of Higher Education
• Original Assignee: University of Pittsburgh of The Commonwealth System of Higher Education
• Inventors: Cui, Xinyan, Alba, Nicolas Alexander, Sun, Mingui
• Primary Examiner(s): Dvorak, Linda
• Assistant Examiner(s): Cardinal, Erin M
• Application Number:
  US14/196,520
• Publication Number:
  US 20140187901A1
• Time in Patent Office: 1,519 Days
• CPC Class Codes: A61B 2562/0215 Silver or silver chloride containing
• CPC Class Codes: A61B 2562/0217 Electrolyte containing
• CPC Class Codes: A61B 2562/125 characterised by the manufacture of electrodes
• CPC Class Codes: A61B 5/24 Detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof
• CPC Class Codes: A61B 5/259 using conductive adhesive means, e.g. gels
• CPC Class Codes: A61B 5/291 for electroencephalography [EEG]
• CPC Class Codes: A61B 5/296 for electromyography [EMG]
• CPC Class Codes: A61N 1/0408 Use-related aspects
• CPC Class Codes: A61N 1/0472 Structure-related aspects
• CPC Class Codes: A61N 1/0484 Garment electrodes worn by the patient
• CPC Class Codes: A61N 1/0492 Patch electrodes A61N1/0412, A61N1/0428 take precedence
• CPC Class Codes: A61N 1/0496 characterised by using specific chemical compositions, e.g. hydrogel compositions, adhesives

Abstract

An electrode system include a flowable and cohesive surface contact element comprising a hydrophilic polymer swollen with an electrolyte fluid, the contact element having a Q′ ratio of at least 5 as defined by the equation

$Q^{\prime }=\frac{W_W}{W_G}$
wherein W_G is the dry weight of the hydrophilic polymer and W_W is weight of water in the sample after absorption of the electrolyte fluid comprising water and an electrolyte salt. The surface contact element can consist essentially of the hydrophilic polymer swollen by the electrolyte fluid. Another electrode system includes a contact element including a crosslinked hydrophilic polymer matrix. The contact element has a Q′ ratio of at least 5 as defined by the equation

$Q^{\prime }=\frac{W_W}{W_G}.$

The contact elements can also have a Q′ ratio of at least 6, at least 7, at least 10 or even at least 11.

Claims

1. A method of applying an electrode system including a conductive electrode element to a surface, comprising:

applying a flowable and cohesive contact element comprising a hydrophilic polymer swollen with an electrolyte fluid to the surface and placing the conductive electrode element in electrical connection with the contact element so that the contact element is positioned between the conductive electrode element and the surface, the contact element having a Q′

ratio of at least 5 as defined by the equation

2. The method of claim 1 wherein the contact element comprises individual particles of crosslinked hydrophilic polymer swollen by the electrolyte fluid.

3. The method of claim 2 wherein the crosslinked hydrophilic polymer comprises polyacrylate or a derivative of polyacrylate.

4. The method of claim 3 wherein the polyacrylate is sodium polyacrylate, potassium polyacrylate or lithium polyacrylate.

5. The method of claim 2 wherein the electrolyte fluid further comprises a penetration enhancer.

6. The method of claim 5 wherein the penetration enhancer comprises urea.

7. The method of claim 1 wherein the contact element Q′

ratio is least 6.

8. The method of claim 1 wherein the contact element Q′

ratio is least 7.

9. The method of claim 1 wherein the contact element Q′

ratio is least 10.

10. The method of claim 9 wherein the contact element has a Q′

ratio of at least 1.5 after drying in air at 37°

C. for 6 hours.

11. The method of claim 9 wherein the contact element has a Q′

ratio of at least 2.0 after drying in air at 37°

C. for 6 hours.

12. The method of claim 9 wherein the contact element has a Q′

ratio of at least 4.0 after drying in air at 37°

C. for 6 hours.

13. The method of claim 1 wherein the conductive electrode element is nonpolarizable.

14. The method of claim 1 wherein the conductive electrode element comprises a silver/silver chloride probe.

15. The method of claim 1 wherein the conductive electrode element comprises a conductive polymer.

16. The method of claim 15 wherein the conductive electrode element comprises a conductive substrate coated on at least a portion thereof with the conductive polymer.

17. The method of claim 1 wherein the conductive electrode element comprises a holder formed of a conductive material in which the contact element is at least partially positioned.