Electrodes possessing change indicator

• US 8,275,441 B2
• Filed: 10/30/2008
• Issued: 09/25/2012
• Est. Priority Date: 11/02/2007
• Status: Active Grant

• Current Assignee: Kpr U.S., LLC (Cardinal Health, Inc.)
• Original Assignee: Tyco Healthcare Group LP (Medtronic Plc)
• Inventors: Copp, Warren, Garstka, Erick, Hyatt, Christopher, Tremblay, Kathleen, Meyer, Peter, Coggins, Scott, Burnes, Lee, Selvitelli, David
• Primary Examiner(s): Cohen, Lee S
• Assistant Examiner(s): Cardinal, Erin M
• Application Number:
  US12/261,134
• Publication Number:
  US 20090270710A1
• Time in Patent Office: 1,426 Days
• Field of Search: 600/382, 600/392, 600/395, 600/396, 252/500, 252/510
• US Class Current: 600/396
• CPC Class Codes: A61B 2560/0276 Determining malfunction
• CPC Class Codes: A61B 2560/028 Arrangements to prevent overuse, e.g. by counting the number of uses
• CPC Class Codes: A61B 2562/0215 Silver or silver chloride containing
• 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: A61N 1/0428 Specially adapted for iontophoresis, e.g. AC, DC or including drug reservoirs
• 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 1/0464 Specially adapted for promoting tissue growth
• CPC Class Codes: A61N 1/0468 Specially adapted for promoting wound healing
• 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

The present disclosure provides electrodes that possess components capable of indicating to an end-user when the electrode is in need of replacement. The electrode includes a substrate and a conductive composition on at least a portion of a surface of the substrate. The conductive composition includes at least one hydrogel and at least one component that precipitates from the hydrogel after repeated use of the electrode, thereby providing an indication to replace the electrode.

Claims

1. A medical electrode comprising:

a substrate; and

a conductive composition on at least a portion of a surface of the substrate, the conductive composition comprising at least one hydrogel and at least one thermochromic material which will change its color or opacity on exposure to heat, thereby providing an indication to replace the electrode.

2. The medical electrode of claim 1, wherein the hydrogel comprises a component selected from the group consisting of gelatin, polysaccharides, crosslinked acrylamide polymers, hydroxyethylmethacrylate polymers, crosslinked polyhydroxyethylacrylate, polymerized, crosslinked 2-acrylamido-2-methylpropane sulfonic acid polymers, crosslinked polyvinylpyrrolidone, polyacrylic acid, copolymers of the foregoing, one or more salts thereof, and combinations thereof.

3. The medical electrode of claim 1, wherein the hydrogel comprises a copolymer comprising a first monomer comprising a mixture of acrylic acid and a salt thereof, present in an amount of from about 8 weight % to about 85 weight % of the hydrogel, and a second monomer of the formula CH₂═

CHC(O)XR, in which X is O or NH and R is an unsubstituted or substituted alkyl group of from 1 to about 5 carbon atoms present in an amount of from about 15 weight % to about 92 weight % of the hydrogel.

4. The medical electrode of claim 1, wherein the hydrogel further comprises an electrolyte present in an amount of from about 0.5% by weight to about 10% by weight of the hydrogel, and optionally a neutralizer selected from the group consisting of ammonium hydroxide, sodium hydroxide, potassium hydroxide, lithium hydroxide, and combinations thereof, optionally further comprises a cross linking agent selected from the group consisting of N-N′

-methylene bis-acrylamide, diethylene glycol diacrylate, diethylene glycol dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, ethoxylated trimethylolpropane triacrylate, ethoxylated trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, and combinations thereof, and optionally further comprises a polymerization initiator selected from the group consisting of 2,2-azobisisobutyronitrile, 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2-hydroxy-1-[4-(2-hydroxyethoxy)phenyl]-2-methyl-1-propan-1-one, 2,2-dimethoxy-2-phenylacetophenone, benzophenone, and combinations thereof.

5. The medical electrode of claim 1, wherein the at least one thermochromic material comprises a liquid crystal selected from the group consisting of cholesteryl nonanoate, cyanobiphenyls, and combinations thereof, present in an amount of from about 0.1% by weight of the hydrogel to about 10% by weight of the hydrogel.

6. The medical electrode of claim 1, wherein the indication to replace the electrode comprises a symbol or message, and wherein the electrode optionally further comprises a conductive layer possessing a coating of silver or silver/silver-chloride on at least a portion of a surface of the conductive layer.