CA1153427A - Tape electrode - Google Patents
Tape electrodeInfo
- Publication number
- CA1153427A CA1153427A CA000341593A CA341593A CA1153427A CA 1153427 A CA1153427 A CA 1153427A CA 000341593 A CA000341593 A CA 000341593A CA 341593 A CA341593 A CA 341593A CA 1153427 A CA1153427 A CA 1153427A
- Authority
- CA
- Canada
- Prior art keywords
- electrode according
- mixtures
- water
- salts
- additional
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/24—Detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof
- A61B5/25—Bioelectric electrodes therefor
- A61B5/251—Means for maintaining electrode contact with the body
- A61B5/257—Means for maintaining electrode contact with the body using adhesive means, e.g. adhesive pads or tapes
- A61B5/259—Means for maintaining electrode contact with the body using adhesive means, e.g. adhesive pads or tapes using conductive adhesive means, e.g. gels
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J133/00—Adhesives based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Adhesives based on derivatives of such polymers
- C09J133/24—Homopolymers or copolymers of amides or imides
- C09J133/26—Homopolymers or copolymers of acrylamide or methacrylamide
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L2666/00—Composition of polymers characterized by a further compound in the blend, being organic macromolecular compounds, natural resins, waxes or and bituminous materials, non-macromolecular organic substances, inorganic substances or characterized by their function in the composition
- C08L2666/28—Non-macromolecular organic substances
- C08L2666/34—Oxygen-containing compounds, including ammonium and metal salts
Abstract
ABSTRACT
An improved medical electrode particularly adap-table to tape-like configurations for use in sensing and stimulation applications in which the electrode is applied to the skin. An essential electrode component comprises a mixture of a polymerized form of 2-acrylamido-2-methylpro-panesulfonic acid or one of its salts with water and/or an alcohol. The mixture possesses electrically conductive properties, flexible properties and adhesive properties, particularly lending itself to skin contact and adhesion.
An improved medical electrode particularly adap-table to tape-like configurations for use in sensing and stimulation applications in which the electrode is applied to the skin. An essential electrode component comprises a mixture of a polymerized form of 2-acrylamido-2-methylpro-panesulfonic acid or one of its salts with water and/or an alcohol. The mixture possesses electrically conductive properties, flexible properties and adhesive properties, particularly lending itself to skin contact and adhesion.
Description
~5~
TAPE ~LECTRODE
I. DESCRIP~ION.
-Background of Prior Art In its preferred embodiments this invention is directed to medical electrodes for application to the skin.Skin electrodes are of varying types and may be used either as transmission electrodes or sensing electrodes. A wide variety of design configurations have been provided in the past ~or these kinds of electrodes. A desirable skin elec-trode is one which maintains good electrical oontact withthe skin and is free of localized current "hot spots". For example, a prior art electrode utilizing karaya gum tends to creep ~n use and flatten out exposing the skin ~o pos-sible direct contact with the current distribution member or lead wire.
It is a~ ~bject of this invention to provide electrodes in which the oomponent contacting the skin po~-sesses superior adhesive properties. The adhesive pro-perties are not appreciably affected by skin moisture, allowing the electrodes ~D be used for several days at a time. It is also substantially homogeneous and creep re-sistant and is thus able to avoid the development of "hot spots". The skin contacting component is also inherently electrically conductive, not requiring electrically conduc-tive additives.
It is a further object of this invention to pro-vide electrodes having desirable elastic properties and wherein the skin-contacting component does not foster the ~L~S3~2~
growth of bacteria or other micro-organisms between the electrode and the skin.
The present invention provides an electrode including:
an adhesive, electrica11y conductive self-supporting gel member comprising as essential components thereof a polymer component selected from the group consis~ing of po1ymerized 2-acrylamido-2-methylpropanesulfonic acid, its salts, copolymers of said acid, copolymers of the salts of said acid, and mixtures thereof, and a second component selected -From the gr~up consisting of water, alcohols and mixtures thereof, sufficient relative amounts of the polymer component and the second component being included to provide adhesiveness and flexibility to the member, and electrical contact means connected to the conductive member.
The present invention also provides an electrode for establishing electrical connection to skin including:
an electrically conductive current distribution member;
electrical terminal means attached to the member, and a self-supporting gel substrate attached to the current distribution member having adhesive, electrically conductive and flexible properties for adhering to the skin and including a polymer component selected from the group consisting of polymerized 2-acrylamido-2-methylpropanesulfonic acid, its salts, copolymers of said acid, copolymers of the salts of said acid, and mixtures thereof and a second component selected from the group consist-ing of water, alcohols and mixtures thereof, sufficient relative amounts of the polymer component and the second component being included to provide adhesiveness and flexibility to the member, the substrate being compatible with normal skin.
Preferably the substrate comprises about 25% to 65% by weight of polymer component and about 75% to 35% by weight water. Alternatively the - substrate preferably comprises either about 30% to 70% by weight of polymer component and about 70% to 30% by weight alcohol or about 30% to 70% by weight polymer component, about 30% to 70% by weight water and about 30%
to 70% by weight alcohol.
TAPE ~LECTRODE
I. DESCRIP~ION.
-Background of Prior Art In its preferred embodiments this invention is directed to medical electrodes for application to the skin.Skin electrodes are of varying types and may be used either as transmission electrodes or sensing electrodes. A wide variety of design configurations have been provided in the past ~or these kinds of electrodes. A desirable skin elec-trode is one which maintains good electrical oontact withthe skin and is free of localized current "hot spots". For example, a prior art electrode utilizing karaya gum tends to creep ~n use and flatten out exposing the skin ~o pos-sible direct contact with the current distribution member or lead wire.
It is a~ ~bject of this invention to provide electrodes in which the oomponent contacting the skin po~-sesses superior adhesive properties. The adhesive pro-perties are not appreciably affected by skin moisture, allowing the electrodes ~D be used for several days at a time. It is also substantially homogeneous and creep re-sistant and is thus able to avoid the development of "hot spots". The skin contacting component is also inherently electrically conductive, not requiring electrically conduc-tive additives.
It is a further object of this invention to pro-vide electrodes having desirable elastic properties and wherein the skin-contacting component does not foster the ~L~S3~2~
growth of bacteria or other micro-organisms between the electrode and the skin.
The present invention provides an electrode including:
an adhesive, electrica11y conductive self-supporting gel member comprising as essential components thereof a polymer component selected from the group consis~ing of po1ymerized 2-acrylamido-2-methylpropanesulfonic acid, its salts, copolymers of said acid, copolymers of the salts of said acid, and mixtures thereof, and a second component selected -From the gr~up consisting of water, alcohols and mixtures thereof, sufficient relative amounts of the polymer component and the second component being included to provide adhesiveness and flexibility to the member, and electrical contact means connected to the conductive member.
The present invention also provides an electrode for establishing electrical connection to skin including:
an electrically conductive current distribution member;
electrical terminal means attached to the member, and a self-supporting gel substrate attached to the current distribution member having adhesive, electrically conductive and flexible properties for adhering to the skin and including a polymer component selected from the group consisting of polymerized 2-acrylamido-2-methylpropanesulfonic acid, its salts, copolymers of said acid, copolymers of the salts of said acid, and mixtures thereof and a second component selected from the group consist-ing of water, alcohols and mixtures thereof, sufficient relative amounts of the polymer component and the second component being included to provide adhesiveness and flexibility to the member, the substrate being compatible with normal skin.
Preferably the substrate comprises about 25% to 65% by weight of polymer component and about 75% to 35% by weight water. Alternatively the - substrate preferably comprises either about 30% to 70% by weight of polymer component and about 70% to 30% by weight alcohol or about 30% to 70% by weight polymer component, about 30% to 70% by weight water and about 30%
to 70% by weight alcohol.
- 2 -~ 27 Preferably, the electrode includes a polymer foam backing member overlying the above current distribution member.
- 2a -~ 5~
Preferably the electrically conductive member or the substrate includes an additional thickening constituent and/or conductivity improving constituent.
Preferably, the alcohol is selected from glycerol and propylene glycol.
According to another aspect of the present invention there is provided a method of forming a conductive member of an electrode, e.g. skin electrode, out of poly-2-acrylamido-2-methylpropanesulfonic acid, its salts, copolymers of the acid, copolymers of the salts of the acids and mixtures thereof. The electrode can for example be formed in situ, i.e. the electrode is formed at the same time as the polymer is formed.
Thus, the present invention in particular provides a method of preparing a conductive member for an electrode, the member containing as an essential component a polymer selected from the group consisting of 2-acryl-amido-2-methylpropanesulfonic acid, its salts, copolymers of the acid~ co-polymers of the salts of the acid and mixtures thereof wherein the polymer component is formed simultaneously with the formation of the member.
The present invention also provides a method of preparing conduc-tive material for skin contacting electrodes comprising:
dissolving a polymerizable material selected from the group con-sisting of 2-acrylamido-2-methylpropanesulfonic acid, its salts and mixtures thereof in a solvent selected from the group consisting of water, alcohols and mixtures thereof, and polymerizing the polymerizable material in the solvent to form the conductive material.
Accordingly, the electrodes of this invention essentially comprise electrical lead means contacting a mixture of polymerized 2-acrylamido-2-methylpropanesulfonic acid or one of its salts with water and/or an alcohol.
Polymer mixtures and copolymers may also be used as described below in detail.
Tlle mixture gels and takes the form of a self-supporting flexible material having adhesive properties. Additionally, it has inherent electrically con-~5~ 7 ductive properties. Other constituents may optionally be included in the mixture and various components such as backing supports and differing elec-trical lead arrangements may be used.
Thus the present invention provides an electrically conductive electrode having adhesive ability (especially over long periods) and compati-bility with normal skin.
In drawings which illustrate a particular embodiment of the present invention;
Figure 1 is a schematic perspective view of an electrode according to the invention.
Figure 2 is an elevational view of the electrode of Figure 1.
Figura 3 is a cross-sectional view taken along line 3-3 of Figure 2.
As previously pointed out, this invention particularly lends it-self to medical electrodes of varying shapes and configurations. For exem-plary purposes herein, a skin electrode 10 is shown in one of the more common rectangular configurations.
Electrode 10 includes flexible, adhesive and conductive member 12 for contacting the skin. An electrical lead 14, including a conductive member 14a and an insulating sheath or covering 14b electrically contacts member 12.
In its most preferred form, as shown in the Figures, the electrode also includes an electrical current distribution member 16 which also elec-trically contacts electrical conductor 14a and member 12. In this configura-tion, member 12 is referred to as a substrate. Current distribution member 16 is preferably formed of a metallic foil, such as stainless steel foil, which is readily available in very thin configuration or form such as .001 inches. Such a foil may be included in the electrode without having any substantial effect on its flexibility. Due to the adhesive nature of the sub-strate 12, the foil readily adheres thereto. A separate adhesive such as is described below may be used for this purpose and in some instances may be - 3a -~5~7 preferred. Other forms of distribution member 16 may be used, such as wire mesh, conductive cloth or the like.
The preferred embodiment of the electrode as shown in the Figures also includes a support or backing 18, the chief purpose of which is to provide a protective and supportive member for the electrode. A preferred backing material is a polymer foam e.g. polyethylene foam. One such mater-ial is commercially available from Fasson, Inc., a division of Avery International of Paynesville, Ohio~ under the trade designation MED 416.
The material is a four pound density cross-linked polyethylene foam coated with a tacky adhesive material of an acrylic type. The foam is 1/16th of an inch thick. However, various thicknesses may be used. The foam need not be coated with the adhesive since it will in most instances, readily adhere to substrate 12 which, as previously pointed out, is adhesive itself. How-ever, the preferred embodiment makes use of the adhesive coated foam, the stainless steel foil current distribution member 16 and the subtrate member 12. The substrate member may be of various thicknesses, about .025 to .250 inches being preferred. Greater thicknesses may be used as dimension is not critical as long as resistance is not excessive for the particular use involved.
~0 In operation and use, electrode 10 is applied with conductive substrate 12 in direct contact with the - 3b -skin. The adhesive pr~perties of substrate 12 eliminate the need for separate adhesive ~ape or any other separate securing measures to h~ld electrode 10 in continuous con-tact with the ski~. Upon prolonged exposure or use, the substrate may be wiped with water or alcohol to increase its adhesiveness. Electrical signals either to ~r from the skin are conducted ~hrough substrate member 12 and the electrical lead means, such as the current distribution member 16 and wire 14, 14 shown in the Figures~
The composition of conductive member 12 i5 unique to the invention. As previously stated, it includes poly-merized 2-acrylamido-2-methylpropanesulfonic acid or a soluble salt thereof mixed with water and/or an alcohol, preferably glycerol or propylene glycol, in flexible sheet-like form. Copolymers of it may also be used and it may be blended with additional polymeric thickeners and the like.
Other alcohols may be used too. The components are pro-vided in such relative amounts as to form a flexible, self-supporting material which has adhesive properties and is electrically conductive.
The 2-acrylamido-2-methylpropanesulfonic acid or its soluhle salt may be incorporated into the mixture in the nomer form and then polymerized. Alternatively, the polymerized acid or its soluble polymeri~ed salt may be in- ~
corporated into the mixture directly. Both approaches are illustrated in the examples below.
In the principal preferred embodiments, the mem-ber 12 is a sheet of polymerized material formed from 2-acrylamido-2-methylpropanesulfonic acid monomer purchased from The Lubrizol Corporation and sold under the tradename AMPS, a registered trademark. The monomer upon being dis-solved in water, is polymerized to attain a sheet-like form which is flexible, conductive and adhesive. It is pre-ferred that the monomer be "refined" grade as per the Lub-rizol "Process For The Manuacture of Refined AMPS" datedDecember 14, 1976. Briefly, refined monomer is made b~
dissolving reaction grade monomer in methanol and recrystal-.. .... .. .. .
lizing it. Examples 1-9 are of this type~
The term "polymer" as t~ed nereinbelow refers to polymers of 2-acrylamido-2-me~hylpropanesulfonic acid or its soluble salts and, where appropriate, it i5 further S characterized by "acid" or "salt" for additional specifi-city. The term "monomer" herein refers to the monomeric form of the compounds.
50 g. of the commercially available acid monomer were dissolved in 50 g. of distilled water. The mixture was purged with nitrogen for about 10 minutes before adding the initiators. Initiator was added. The Lubrizol Corp.
recommends ferrous sulfate and hydrogen peroxide in small amounts eg., .01 9. ferrous sulfate heptahydrate and .25 g.
hydrogen peroxide in a .05% solution, which was used in this example. Upon addition of the initiator, the mixture was poured into a tray in an enclosed nitrogen atmosphere to form a rectangular sheet having a thickness of about .125 inches. .25 inch thick sheets have also been prepared in this way. After pouring, the mixture rapidly gelled to a flexible material with adhesive conductive gualities.
25g. of the acid monomer were dissolved in 25 ml.
of deionized water. 4.24 g. of ammonium hydroxide were then dissolved in this mixture. The solution was purged with nitrogen for about 10 minutes and polymerization ini-tiator was then added. The initiator was 1 ml. of a .38 g./100 ml. solution of potassium bisulfite, 1 ml~ of a .38 g./lOQ ml. solution of potassium persulfate and 1 ml. of a .24 g.~100 ml. solution of ferrous sulfate heptahydrate.
15 seconds was allowed for mixing then the mixture was poured into a mold under a nitrogen atmosphere to ~orm the sheet material, The mixture rapidly gelled as in Example 1. .
EXA~DPLE 3 Same as Example 2 except 4.50 g. of lithium car-bonate were substituted for the ammonium hydroxide. The resistance of the sheet was 7.5 kilo ohms for a sheet sam-ple 1.5 X 1 X .12S inches.
~AMPLE 4 Same as Example 2 e~cept 8.36 g. of potassiumcarbonate were substituted for the ammonium hydroxide. The resistance of the sheet was 2.1 kilo ohms for a sheet sample 1.5 X 1 X .125 inches.
Same as Example ~ except 10.16 g. of sodium bi-carbonate were substituted for the ammonium hydroxide. The resistance of the sheet was 2.1 kilo ohms for a sheet sample 1.~ X 1 X .125 inches.
EXAMPL~ 6 Another example of polymerizing the monomer and forming the sheet simul~aneously was provided by mixing 50 g. of the monomer with 35 ml. of distilled water and 15 ml. of glycerol. The primary purpose of the addition of an alcohol such as glycerol is to retard drying of the polymerized sheet. The mixture was purged with nitrogen by bubbling about 10 minutes to substantially remove oxygen.
Initiator in the form of 1 ml. of a .15~ hydrogen peroxide solution was added. The mixture was then poured onto re-lease paper (a silicone ooated paper) under a nitrogen atmosphere and it very quickly gelled to be self-supporting.
It was then placed in an oven at 50C for two hours to remove sur-face moisture. -When placed in the oven o~ernight at 50C, the material lost substantial tackiness. However, the surface of the material which was against the release paper retained good adhesive properties.
_ . . . . , . . . . . , . . , .. _ ,. ,. . . .. . _ The same procedure was used as in Example 6 except that 10 ml. of glycerol and 4n ml. of water were used.
The resulting sheet was more firm than that of Example 6.
Another sheet electrode was prepared as in Example 1. After polymerization, the electrode surface was wiped with glycerol and left exposed to ambient environment.
Wiping was fcund to retard drying for at least 7 days~
Ho~ever, storage in sealed plastic bags was also found to be effective in preventing drying of the polymer sheet.
Eight sheet-like pads of polymerized material were prepared as in Example 1 e~cept the initiator used was: 1 ml. of a .38 g./lOO ml solution of potassium bisul-fite, 1 ml of a .38 g./lOO ml solution of potassium persul-fate and 1 ml of a .24 g./100 ml solution of ferrous sul-fate heptahydrate. Each pad was about 4.5 X 7 X 0.125 inches in size. They were tested for skin irritation on both laboratory animals and humans with no primary skin irritation resulting.
The typical electrical resistivity of the poly-merized sheet prepared and described in Examples 1 and 6-~
was about 3 X 102 ohm-cm. and the sheet was substantially colorless and substantially transparent in appearance.
The monomer and its salts may be polymerized in aqueous solutions by common water soluble radical initiators~
or redox systems. It can also be polymerized in emulsion, rather than in solution, using o~mmon vinyl polymerization techniques. The molecular weight of the polymer may be varied by changing the initiator o~ncentration, the monomer concentration, the temperature or by the use of a chain transfer agent such as a mercaptan.
The molecular weight of the polymer formed for use herein is not-critical so long as it is high enough to form a self-supporting gel. The higher the molecular weight, the easier the material is to handle and the better its performance, such as resistance to creep and dehydration.
Since the polymer itself ie., poly-2-acrylamido-2-methylpropanesulfonic acid and many of its polymerized salts are water soluble, the substrate member may also be prepared by dissolving already formed polymer in water or other suitable solvents such as alcohols and forming sheet or film of desired thickness by compression forming or by solut~on casting and evaporating.
10 Additional constituents may be mixed with the polymer in such preparations also. Examples of such mix-tures or "blends" are included below. Sheets of each were prepared and tested. The mixtures, in the amounts indicated below, were stirred together, placed between two pieces of mylar, pressed to desired thickness to form sheet or film, and dried overnight in an oven at 50C.
`EXAMPLE 10 -Xanthan gum (as additional thickener) 4.8 g.
acid polymer 0.2 g.
water 1.0 g.
glycerol 7 0 g flexibility-good, adhesion-good, residue*-marginal, elas-ticity-acceptable, compression**-excellent.
Karaya gum (as additional thickener) 2.4 g.
acid polymer 0.1 g.
glycerol 3.5 g.
water 0 5 g flexibility-excellent, adhèsion-very good, residue-very good, elasticity-excellent, compression-excellent.
*residue-tacky mat~rial left on skin after removal of electrode.
**compression-resistance to flow with pressure.
~3~7 _g E~AMP~E 12 Polyacrylamide-grafted corn starch (as additional ~hickener) 2.4 g.
acid polymer 0.1 g.
glycerol 3~5 g-water 0.5 g.
Adhesion-excellent, compression~excellent. Resistivity 1.56 X 10~4 ohm-cm.
Hydroxypropyl Guar 2 4 (as additional thickener) . g.
acid polymer 0.1 g.
glycerol 3.5 g.
water 0 5 g-Adhesion-good, compression-good, residue-very good. Resis-ti~ity 9.3`X 10 ohm-cm.
EXA~LE 14 Evànol (a polyvinyl alcohol, as 2 4 additional thickener) . g.
acid polymer 0.1 g.
glycerol 3.5 g.
water 0 5 g-Resistivity 6.89 X 103 ohm-cm.
Polyvinylpyrollidone (as additional thlckener) 2.5 g.
acid polymer 1.5 g.
glycerol 7. g.
Water 1. g.
30 Adhesion-very good. Resistivity 3.32 X 10 ohm-cm.
Polyvinylpyrollidone (as additional ~hickener3 3. g.
acid polymer 1. g.
glycerol 4. g.
methanol 10. g.
water 1. g.
Adhesion-very good. Other properties-average.
~XAMP~LE 17 Polyacrylamide-grafted corn starch (as an additional thickener) 2 g.
acid polymer 2 g.
water 4 g-glycerol 4 g' heat to 80C and press to sheet fQrm. Resistivity 1.56 X
10 ohm-cm.
Polyvinylpyrollidone ~as additional ~hickener) 2 g.
acid polymer 2 g.
water 4 g.
glycerol 4 g.
heat to 80C and press to sheet form. Resistivity 3.32 X
1o2 ohm cm.
Evanol ~a polyvinyl alcohol as additional thickener) 2 gO
acid polymer 2 g.
water 4 g glycerol 4 g~
heat to 80C add press to sheet orm. Resistivity 6.89 X
10 ohm-cm.
EXA~LE 20 Xanthan gum (as additional thickener) 2 g.
acid polymer 2 g.
water 4 g~
glycerol 4 g.
??~-~?~
heat to 80C and pressed to sheet form. Resistlvi~y 2.6 X
102 ohm-cm.
EXAMæ~F 21 Hydroxypropyl guar (as additional thickener) 2 g.
acid polymer 2 g.
water 4 Y~
glycerol 4 g.
heat to 80C and press to sheet form. Resistivity 9.39 X
10 10~ ohm-cm.
Xanthan gum 10 g.
polymer salt (lithium carbonate salt) 2 g.
glycerol 10 g.
water 10 g.
heat to 80~C and press to sheet form. Flexibility-accept~-able, adhesion-acceptable, residue-acceptable, elasticity-acceptable, compression-acceptable.
~ Guar gum 10 g.
polymer salt (lithium carbonate salt) 3 g.
glycerol 10 g.
water 10 g.
heat to 80C and press to sheet form. Flexibility-accept-able, adhesion-acceptable, residue-acceptable, elasticity-acceptable, compression-acceptable.
The Xanthan gum used herein was Galaxy XB Xanthan gum obtained from General Mills Chemicals as was the starch graft polymer used (SGP5025) and the hydroxypropyl guar used (HPG406). The Evanol was E.I. DuPont de Nemours and Co. grade 51-05 polyvinyl alcohol. The polyvinylpyrolli-done was obtained from General Aniline and Film Corp. con-trol No. 390.
~5 Copolymers of the polymerized monomer may also be used as the conductivP member 12. For example, copoly-mers have been successfully prepared with acrylamide, N-vinylpyrollidone and acrylic acid. Specific examples of copolymerization with acrylamide and with acrylic acid are as follows:
EXAM~E 24 Preparation and polymerizat.ion same as in Example ~1 .
~cid monomer 49.7 g.
acrylamide 17.04 g.
water ~ lO0 g.
potassium bisulfite (initiator) 2 ml of .38 ~. /100 solution potassium persulfate (initiator) 2 ml of .38 gO/100 solution ferrous Sulfate heptahydrate (initiator) 2 ml of .24 g./lO0 solution The resistance for a 1 X 1.5 X .125 inch sheet was 13 kilo ohms.
Acid monomer 25 g.
acrylic acid 4 g.
water 25 g.
potassium bisulfite (initiator) l ml of .38 g./lO0 solution potassium persulfate (initiator) l ml of .38 g./100 solution ferrous sulfate heptahydrate (initiator)l ml of .24 g. /100 solution Th~ resistance oî a 1 X 1~5 X .125 inch sheet was 1.5 kilo ohms .
In general, the pre Eerred relative amounts of the constituents to be used in forming the skin contacting member 12 are indicated below.
Nominal Amounts Range of IngredientsIngredients % by weight~ by weight Polymer~water about 50~50 about 25-65/75--polymer/alcohol about 70~30 about 30-70/70-.
polymer/water~alcohol about 33/33/33 about 30-70/30-As can be seen from the examples provided herein, a wide variety of additives may be included in the conduc-tive member 12, it only being necessary that it include in varying amounts, the essential polymer or copolymer of 2-acrylamido-2-methylpropanesulfonic acid or one of its solu-ble salts. Generally, any amoullt of polymer is satisfac-tory so long as a sufficient amount is included with water and/or alcohol to provide the requisite adhesive and flex-ible qualities. Various thicknesses may be used as desired and any electrode configuration with or without -backing support- and current distribution member may be used.
Many changes and embodiments of the invention will become apparent to those of ordinary skill in this art without departing from the scope of the invention. The description herein is -not intended to be limiting in any sense and the exclusive property rights claimed are defined hereinbelow.
t~
SUPPLE~ NTARY DISCLOSURE
As indicated in the prineipal disclosure the present invention relates to an electrode including:
an adhesive, electrically conductive member compTising as essential components thereof a polymer component selected from the group consisting of polymerized 2-acrylamido-2-methylpropanesulfonic acid, its salts, copolymers of said acid, copolymers of the salts of said acid, and mixtures thereof, and a second CQmpOnent selected from the group consisting of water, alcohols and mixtures thereof, sufficient relative amounts of the polymer component and the second component being included to provide adhesi~eness and flexibility to the member, ~nd electrical contact means connected to the conductive member.
The present invention also relates to an electrod~ for establishing electrical connection to skin including:
an electrically conductive current distribution member;
electrical terminal means attached to the member, and a substrate attached to the current distribution member having adhesive, eleetrical conductive and flexible properties for adhering to the skin and including a polymer component selected from the group consisting of polymerized 2-acrylamido-2-methylpropanesulfonic acid, its salts, copolymers of said acid, copolymers of the salts of said acid, and mixtures thereof and a second component selected from the group consisting o water, alcohols and ~ixtures thereof.
Preferably the substrate comprises about 25% to 65% by weight of polymer component and about 75% to 35% by weight water. Alte~natively the substrate preferably comprises either about 30% to 70% by weight of polymer component and about 70% to 30% by weight alcohol or about 30% to 70% by weight polymer component) about 30% to 70% by weight water and about 30% to 70% by weight alcohol.
Preferably, the electrode includes a polymer ~oam backing member overlying the above current distribution member.
:'~
~!Lq~ 7 Preferably the electrically conductive member or the substrate includes an additional thickening constituent.
Preferably, the alcohvl is selected from glycerol and propylene glycol.
Accordîng to another aspect the present invention relates to a method of forming a cond-lctive member of an electrode, e.g. skin electrode, out of poly-2-acrylamido-2-methylpropanesulfonic acid~ its sal~s, copolymers of the acid, copolymers of the salts of the acids and mixtures thereof. The electrode can for example be formed in situ, i.e. the electrode is formed at the same time as the polymer is fo~med.
Thus, the present invention in particular relates to a method of p~eparing a conductive member for an electrode, the member containing as an essential component a polymer selected from ~he group consisting of 2-acryl-amido-2-methylpropanesulfonic acid, its salts, copolymers of the acid, co-polymers of the salts of the acid and mixtures thereof wherein the polymer component is formed simultaneously with the formation of the member.
The present invention also relates to a method of preparing conduc-tive mateTial for skin contacting elec~rodes comprising:
dissolving a polymerizable material selected from the gTOUp con-2Q sisting of 2-acrylamido-2-methylpropanesulfonic acid, its salts and mixtures thereof in a solvent selected from the group consisting of water, alcohols and mixtures thereof, and polymerizing the polymerizable material in the solvent to form the conductive material.
Accosdingly, the electrodes of this invention essentially comprise electrical lead means contacting a mixture of polymerized 2-acrylamido-2-methylpropanesulfonic acid OT one of its salts with water andtor an alcohol.
Specific embodiments of the invention are described in the examples of the principal disclosure.
It is important to understand that all of ~he materials descTibed above by way of Example exhibit high conductivity. However, a conductivity improving constituent may be included in the electrically conductive ~5~ 7 member or substra~e. In particular, the addition of soluble, ionizable metal salts such as KCl and NaCl has an additional benefit in the electrical properties of sensing or monitoring type electrodes. Chloride salts are particularly prefeTred. While it is generally accepted ~hat salt addition to water soluble polymers improves conductivity, salt addition ~o the polymer impToves conductivity only slightly, not on an order of tenfold. Neverthe-less, it does provide unusually improved sensing properties as in EKG
testing for example.
Follo~ing are examples o electrodes in which salt has beer, added.
The same purging treatment and initiator were used as described above for E~ample 2. Thickness of the substrate materiai was about .100 inches.
89.3 grams of a 56% sodium salt solution of monomer were mixed with 7.7 grams of polyacrylic acid and 2.2 grams of 1% methylene-bis-acrylamide solution. To this solution~ 1.0 grams of NaCl was added. The resultant polymerized product consisted of cross-linked polymer blended with polyacrylic acid and showed enhanced electrical conductivity properties. In sensing applications, decreased motion artifacts were noted i.e., less background noise as opposed to the same formulation without NaCl.
EXAMPLE 2?
114 grams of a 56% sodium salt solution of monomer were mixed with 6 grams of glycerine and 2 milliliters of a 1% solution of me~hylene-bis-acrylamide. To this solution, 1 gram of NaCl was added. Again, the resultant polymerized product had enhanced properties as in Example 25 that were not present befoTe the addition of NaCl.
The polyacrylic acid added to the adhesiveness of the material and the methylene-bis-acrylamide caused cross-linking of the polymer.
~t~
- 2a -~ 5~
Preferably the electrically conductive member or the substrate includes an additional thickening constituent and/or conductivity improving constituent.
Preferably, the alcohol is selected from glycerol and propylene glycol.
According to another aspect of the present invention there is provided a method of forming a conductive member of an electrode, e.g. skin electrode, out of poly-2-acrylamido-2-methylpropanesulfonic acid, its salts, copolymers of the acid, copolymers of the salts of the acids and mixtures thereof. The electrode can for example be formed in situ, i.e. the electrode is formed at the same time as the polymer is formed.
Thus, the present invention in particular provides a method of preparing a conductive member for an electrode, the member containing as an essential component a polymer selected from the group consisting of 2-acryl-amido-2-methylpropanesulfonic acid, its salts, copolymers of the acid~ co-polymers of the salts of the acid and mixtures thereof wherein the polymer component is formed simultaneously with the formation of the member.
The present invention also provides a method of preparing conduc-tive material for skin contacting electrodes comprising:
dissolving a polymerizable material selected from the group con-sisting of 2-acrylamido-2-methylpropanesulfonic acid, its salts and mixtures thereof in a solvent selected from the group consisting of water, alcohols and mixtures thereof, and polymerizing the polymerizable material in the solvent to form the conductive material.
Accordingly, the electrodes of this invention essentially comprise electrical lead means contacting a mixture of polymerized 2-acrylamido-2-methylpropanesulfonic acid or one of its salts with water and/or an alcohol.
Polymer mixtures and copolymers may also be used as described below in detail.
Tlle mixture gels and takes the form of a self-supporting flexible material having adhesive properties. Additionally, it has inherent electrically con-~5~ 7 ductive properties. Other constituents may optionally be included in the mixture and various components such as backing supports and differing elec-trical lead arrangements may be used.
Thus the present invention provides an electrically conductive electrode having adhesive ability (especially over long periods) and compati-bility with normal skin.
In drawings which illustrate a particular embodiment of the present invention;
Figure 1 is a schematic perspective view of an electrode according to the invention.
Figure 2 is an elevational view of the electrode of Figure 1.
Figura 3 is a cross-sectional view taken along line 3-3 of Figure 2.
As previously pointed out, this invention particularly lends it-self to medical electrodes of varying shapes and configurations. For exem-plary purposes herein, a skin electrode 10 is shown in one of the more common rectangular configurations.
Electrode 10 includes flexible, adhesive and conductive member 12 for contacting the skin. An electrical lead 14, including a conductive member 14a and an insulating sheath or covering 14b electrically contacts member 12.
In its most preferred form, as shown in the Figures, the electrode also includes an electrical current distribution member 16 which also elec-trically contacts electrical conductor 14a and member 12. In this configura-tion, member 12 is referred to as a substrate. Current distribution member 16 is preferably formed of a metallic foil, such as stainless steel foil, which is readily available in very thin configuration or form such as .001 inches. Such a foil may be included in the electrode without having any substantial effect on its flexibility. Due to the adhesive nature of the sub-strate 12, the foil readily adheres thereto. A separate adhesive such as is described below may be used for this purpose and in some instances may be - 3a -~5~7 preferred. Other forms of distribution member 16 may be used, such as wire mesh, conductive cloth or the like.
The preferred embodiment of the electrode as shown in the Figures also includes a support or backing 18, the chief purpose of which is to provide a protective and supportive member for the electrode. A preferred backing material is a polymer foam e.g. polyethylene foam. One such mater-ial is commercially available from Fasson, Inc., a division of Avery International of Paynesville, Ohio~ under the trade designation MED 416.
The material is a four pound density cross-linked polyethylene foam coated with a tacky adhesive material of an acrylic type. The foam is 1/16th of an inch thick. However, various thicknesses may be used. The foam need not be coated with the adhesive since it will in most instances, readily adhere to substrate 12 which, as previously pointed out, is adhesive itself. How-ever, the preferred embodiment makes use of the adhesive coated foam, the stainless steel foil current distribution member 16 and the subtrate member 12. The substrate member may be of various thicknesses, about .025 to .250 inches being preferred. Greater thicknesses may be used as dimension is not critical as long as resistance is not excessive for the particular use involved.
~0 In operation and use, electrode 10 is applied with conductive substrate 12 in direct contact with the - 3b -skin. The adhesive pr~perties of substrate 12 eliminate the need for separate adhesive ~ape or any other separate securing measures to h~ld electrode 10 in continuous con-tact with the ski~. Upon prolonged exposure or use, the substrate may be wiped with water or alcohol to increase its adhesiveness. Electrical signals either to ~r from the skin are conducted ~hrough substrate member 12 and the electrical lead means, such as the current distribution member 16 and wire 14, 14 shown in the Figures~
The composition of conductive member 12 i5 unique to the invention. As previously stated, it includes poly-merized 2-acrylamido-2-methylpropanesulfonic acid or a soluble salt thereof mixed with water and/or an alcohol, preferably glycerol or propylene glycol, in flexible sheet-like form. Copolymers of it may also be used and it may be blended with additional polymeric thickeners and the like.
Other alcohols may be used too. The components are pro-vided in such relative amounts as to form a flexible, self-supporting material which has adhesive properties and is electrically conductive.
The 2-acrylamido-2-methylpropanesulfonic acid or its soluhle salt may be incorporated into the mixture in the nomer form and then polymerized. Alternatively, the polymerized acid or its soluble polymeri~ed salt may be in- ~
corporated into the mixture directly. Both approaches are illustrated in the examples below.
In the principal preferred embodiments, the mem-ber 12 is a sheet of polymerized material formed from 2-acrylamido-2-methylpropanesulfonic acid monomer purchased from The Lubrizol Corporation and sold under the tradename AMPS, a registered trademark. The monomer upon being dis-solved in water, is polymerized to attain a sheet-like form which is flexible, conductive and adhesive. It is pre-ferred that the monomer be "refined" grade as per the Lub-rizol "Process For The Manuacture of Refined AMPS" datedDecember 14, 1976. Briefly, refined monomer is made b~
dissolving reaction grade monomer in methanol and recrystal-.. .... .. .. .
lizing it. Examples 1-9 are of this type~
The term "polymer" as t~ed nereinbelow refers to polymers of 2-acrylamido-2-me~hylpropanesulfonic acid or its soluble salts and, where appropriate, it i5 further S characterized by "acid" or "salt" for additional specifi-city. The term "monomer" herein refers to the monomeric form of the compounds.
50 g. of the commercially available acid monomer were dissolved in 50 g. of distilled water. The mixture was purged with nitrogen for about 10 minutes before adding the initiators. Initiator was added. The Lubrizol Corp.
recommends ferrous sulfate and hydrogen peroxide in small amounts eg., .01 9. ferrous sulfate heptahydrate and .25 g.
hydrogen peroxide in a .05% solution, which was used in this example. Upon addition of the initiator, the mixture was poured into a tray in an enclosed nitrogen atmosphere to form a rectangular sheet having a thickness of about .125 inches. .25 inch thick sheets have also been prepared in this way. After pouring, the mixture rapidly gelled to a flexible material with adhesive conductive gualities.
25g. of the acid monomer were dissolved in 25 ml.
of deionized water. 4.24 g. of ammonium hydroxide were then dissolved in this mixture. The solution was purged with nitrogen for about 10 minutes and polymerization ini-tiator was then added. The initiator was 1 ml. of a .38 g./100 ml. solution of potassium bisulfite, 1 ml~ of a .38 g./lOQ ml. solution of potassium persulfate and 1 ml. of a .24 g.~100 ml. solution of ferrous sulfate heptahydrate.
15 seconds was allowed for mixing then the mixture was poured into a mold under a nitrogen atmosphere to ~orm the sheet material, The mixture rapidly gelled as in Example 1. .
EXA~DPLE 3 Same as Example 2 except 4.50 g. of lithium car-bonate were substituted for the ammonium hydroxide. The resistance of the sheet was 7.5 kilo ohms for a sheet sam-ple 1.5 X 1 X .12S inches.
~AMPLE 4 Same as Example 2 e~cept 8.36 g. of potassiumcarbonate were substituted for the ammonium hydroxide. The resistance of the sheet was 2.1 kilo ohms for a sheet sample 1.5 X 1 X .125 inches.
Same as Example ~ except 10.16 g. of sodium bi-carbonate were substituted for the ammonium hydroxide. The resistance of the sheet was 2.1 kilo ohms for a sheet sample 1.~ X 1 X .125 inches.
EXAMPL~ 6 Another example of polymerizing the monomer and forming the sheet simul~aneously was provided by mixing 50 g. of the monomer with 35 ml. of distilled water and 15 ml. of glycerol. The primary purpose of the addition of an alcohol such as glycerol is to retard drying of the polymerized sheet. The mixture was purged with nitrogen by bubbling about 10 minutes to substantially remove oxygen.
Initiator in the form of 1 ml. of a .15~ hydrogen peroxide solution was added. The mixture was then poured onto re-lease paper (a silicone ooated paper) under a nitrogen atmosphere and it very quickly gelled to be self-supporting.
It was then placed in an oven at 50C for two hours to remove sur-face moisture. -When placed in the oven o~ernight at 50C, the material lost substantial tackiness. However, the surface of the material which was against the release paper retained good adhesive properties.
_ . . . . , . . . . . , . . , .. _ ,. ,. . . .. . _ The same procedure was used as in Example 6 except that 10 ml. of glycerol and 4n ml. of water were used.
The resulting sheet was more firm than that of Example 6.
Another sheet electrode was prepared as in Example 1. After polymerization, the electrode surface was wiped with glycerol and left exposed to ambient environment.
Wiping was fcund to retard drying for at least 7 days~
Ho~ever, storage in sealed plastic bags was also found to be effective in preventing drying of the polymer sheet.
Eight sheet-like pads of polymerized material were prepared as in Example 1 e~cept the initiator used was: 1 ml. of a .38 g./lOO ml solution of potassium bisul-fite, 1 ml of a .38 g./lOO ml solution of potassium persul-fate and 1 ml of a .24 g./100 ml solution of ferrous sul-fate heptahydrate. Each pad was about 4.5 X 7 X 0.125 inches in size. They were tested for skin irritation on both laboratory animals and humans with no primary skin irritation resulting.
The typical electrical resistivity of the poly-merized sheet prepared and described in Examples 1 and 6-~
was about 3 X 102 ohm-cm. and the sheet was substantially colorless and substantially transparent in appearance.
The monomer and its salts may be polymerized in aqueous solutions by common water soluble radical initiators~
or redox systems. It can also be polymerized in emulsion, rather than in solution, using o~mmon vinyl polymerization techniques. The molecular weight of the polymer may be varied by changing the initiator o~ncentration, the monomer concentration, the temperature or by the use of a chain transfer agent such as a mercaptan.
The molecular weight of the polymer formed for use herein is not-critical so long as it is high enough to form a self-supporting gel. The higher the molecular weight, the easier the material is to handle and the better its performance, such as resistance to creep and dehydration.
Since the polymer itself ie., poly-2-acrylamido-2-methylpropanesulfonic acid and many of its polymerized salts are water soluble, the substrate member may also be prepared by dissolving already formed polymer in water or other suitable solvents such as alcohols and forming sheet or film of desired thickness by compression forming or by solut~on casting and evaporating.
10 Additional constituents may be mixed with the polymer in such preparations also. Examples of such mix-tures or "blends" are included below. Sheets of each were prepared and tested. The mixtures, in the amounts indicated below, were stirred together, placed between two pieces of mylar, pressed to desired thickness to form sheet or film, and dried overnight in an oven at 50C.
`EXAMPLE 10 -Xanthan gum (as additional thickener) 4.8 g.
acid polymer 0.2 g.
water 1.0 g.
glycerol 7 0 g flexibility-good, adhesion-good, residue*-marginal, elas-ticity-acceptable, compression**-excellent.
Karaya gum (as additional thickener) 2.4 g.
acid polymer 0.1 g.
glycerol 3.5 g.
water 0 5 g flexibility-excellent, adhèsion-very good, residue-very good, elasticity-excellent, compression-excellent.
*residue-tacky mat~rial left on skin after removal of electrode.
**compression-resistance to flow with pressure.
~3~7 _g E~AMP~E 12 Polyacrylamide-grafted corn starch (as additional ~hickener) 2.4 g.
acid polymer 0.1 g.
glycerol 3~5 g-water 0.5 g.
Adhesion-excellent, compression~excellent. Resistivity 1.56 X 10~4 ohm-cm.
Hydroxypropyl Guar 2 4 (as additional thickener) . g.
acid polymer 0.1 g.
glycerol 3.5 g.
water 0 5 g-Adhesion-good, compression-good, residue-very good. Resis-ti~ity 9.3`X 10 ohm-cm.
EXA~LE 14 Evànol (a polyvinyl alcohol, as 2 4 additional thickener) . g.
acid polymer 0.1 g.
glycerol 3.5 g.
water 0 5 g-Resistivity 6.89 X 103 ohm-cm.
Polyvinylpyrollidone (as additional thlckener) 2.5 g.
acid polymer 1.5 g.
glycerol 7. g.
Water 1. g.
30 Adhesion-very good. Resistivity 3.32 X 10 ohm-cm.
Polyvinylpyrollidone (as additional ~hickener3 3. g.
acid polymer 1. g.
glycerol 4. g.
methanol 10. g.
water 1. g.
Adhesion-very good. Other properties-average.
~XAMP~LE 17 Polyacrylamide-grafted corn starch (as an additional thickener) 2 g.
acid polymer 2 g.
water 4 g-glycerol 4 g' heat to 80C and press to sheet fQrm. Resistivity 1.56 X
10 ohm-cm.
Polyvinylpyrollidone ~as additional ~hickener) 2 g.
acid polymer 2 g.
water 4 g.
glycerol 4 g.
heat to 80C and press to sheet form. Resistivity 3.32 X
1o2 ohm cm.
Evanol ~a polyvinyl alcohol as additional thickener) 2 gO
acid polymer 2 g.
water 4 g glycerol 4 g~
heat to 80C add press to sheet orm. Resistivity 6.89 X
10 ohm-cm.
EXA~LE 20 Xanthan gum (as additional thickener) 2 g.
acid polymer 2 g.
water 4 g~
glycerol 4 g.
??~-~?~
heat to 80C and pressed to sheet form. Resistlvi~y 2.6 X
102 ohm-cm.
EXAMæ~F 21 Hydroxypropyl guar (as additional thickener) 2 g.
acid polymer 2 g.
water 4 Y~
glycerol 4 g.
heat to 80C and press to sheet form. Resistivity 9.39 X
10 10~ ohm-cm.
Xanthan gum 10 g.
polymer salt (lithium carbonate salt) 2 g.
glycerol 10 g.
water 10 g.
heat to 80~C and press to sheet form. Flexibility-accept~-able, adhesion-acceptable, residue-acceptable, elasticity-acceptable, compression-acceptable.
~ Guar gum 10 g.
polymer salt (lithium carbonate salt) 3 g.
glycerol 10 g.
water 10 g.
heat to 80C and press to sheet form. Flexibility-accept-able, adhesion-acceptable, residue-acceptable, elasticity-acceptable, compression-acceptable.
The Xanthan gum used herein was Galaxy XB Xanthan gum obtained from General Mills Chemicals as was the starch graft polymer used (SGP5025) and the hydroxypropyl guar used (HPG406). The Evanol was E.I. DuPont de Nemours and Co. grade 51-05 polyvinyl alcohol. The polyvinylpyrolli-done was obtained from General Aniline and Film Corp. con-trol No. 390.
~5 Copolymers of the polymerized monomer may also be used as the conductivP member 12. For example, copoly-mers have been successfully prepared with acrylamide, N-vinylpyrollidone and acrylic acid. Specific examples of copolymerization with acrylamide and with acrylic acid are as follows:
EXAM~E 24 Preparation and polymerizat.ion same as in Example ~1 .
~cid monomer 49.7 g.
acrylamide 17.04 g.
water ~ lO0 g.
potassium bisulfite (initiator) 2 ml of .38 ~. /100 solution potassium persulfate (initiator) 2 ml of .38 gO/100 solution ferrous Sulfate heptahydrate (initiator) 2 ml of .24 g./lO0 solution The resistance for a 1 X 1.5 X .125 inch sheet was 13 kilo ohms.
Acid monomer 25 g.
acrylic acid 4 g.
water 25 g.
potassium bisulfite (initiator) l ml of .38 g./lO0 solution potassium persulfate (initiator) l ml of .38 g./100 solution ferrous sulfate heptahydrate (initiator)l ml of .24 g. /100 solution Th~ resistance oî a 1 X 1~5 X .125 inch sheet was 1.5 kilo ohms .
In general, the pre Eerred relative amounts of the constituents to be used in forming the skin contacting member 12 are indicated below.
Nominal Amounts Range of IngredientsIngredients % by weight~ by weight Polymer~water about 50~50 about 25-65/75--polymer/alcohol about 70~30 about 30-70/70-.
polymer/water~alcohol about 33/33/33 about 30-70/30-As can be seen from the examples provided herein, a wide variety of additives may be included in the conduc-tive member 12, it only being necessary that it include in varying amounts, the essential polymer or copolymer of 2-acrylamido-2-methylpropanesulfonic acid or one of its solu-ble salts. Generally, any amoullt of polymer is satisfac-tory so long as a sufficient amount is included with water and/or alcohol to provide the requisite adhesive and flex-ible qualities. Various thicknesses may be used as desired and any electrode configuration with or without -backing support- and current distribution member may be used.
Many changes and embodiments of the invention will become apparent to those of ordinary skill in this art without departing from the scope of the invention. The description herein is -not intended to be limiting in any sense and the exclusive property rights claimed are defined hereinbelow.
t~
SUPPLE~ NTARY DISCLOSURE
As indicated in the prineipal disclosure the present invention relates to an electrode including:
an adhesive, electrically conductive member compTising as essential components thereof a polymer component selected from the group consisting of polymerized 2-acrylamido-2-methylpropanesulfonic acid, its salts, copolymers of said acid, copolymers of the salts of said acid, and mixtures thereof, and a second CQmpOnent selected from the group consisting of water, alcohols and mixtures thereof, sufficient relative amounts of the polymer component and the second component being included to provide adhesi~eness and flexibility to the member, ~nd electrical contact means connected to the conductive member.
The present invention also relates to an electrod~ for establishing electrical connection to skin including:
an electrically conductive current distribution member;
electrical terminal means attached to the member, and a substrate attached to the current distribution member having adhesive, eleetrical conductive and flexible properties for adhering to the skin and including a polymer component selected from the group consisting of polymerized 2-acrylamido-2-methylpropanesulfonic acid, its salts, copolymers of said acid, copolymers of the salts of said acid, and mixtures thereof and a second component selected from the group consisting o water, alcohols and ~ixtures thereof.
Preferably the substrate comprises about 25% to 65% by weight of polymer component and about 75% to 35% by weight water. Alte~natively the substrate preferably comprises either about 30% to 70% by weight of polymer component and about 70% to 30% by weight alcohol or about 30% to 70% by weight polymer component) about 30% to 70% by weight water and about 30% to 70% by weight alcohol.
Preferably, the electrode includes a polymer ~oam backing member overlying the above current distribution member.
:'~
~!Lq~ 7 Preferably the electrically conductive member or the substrate includes an additional thickening constituent.
Preferably, the alcohvl is selected from glycerol and propylene glycol.
Accordîng to another aspect the present invention relates to a method of forming a cond-lctive member of an electrode, e.g. skin electrode, out of poly-2-acrylamido-2-methylpropanesulfonic acid~ its sal~s, copolymers of the acid, copolymers of the salts of the acids and mixtures thereof. The electrode can for example be formed in situ, i.e. the electrode is formed at the same time as the polymer is fo~med.
Thus, the present invention in particular relates to a method of p~eparing a conductive member for an electrode, the member containing as an essential component a polymer selected from ~he group consisting of 2-acryl-amido-2-methylpropanesulfonic acid, its salts, copolymers of the acid, co-polymers of the salts of the acid and mixtures thereof wherein the polymer component is formed simultaneously with the formation of the member.
The present invention also relates to a method of preparing conduc-tive mateTial for skin contacting elec~rodes comprising:
dissolving a polymerizable material selected from the gTOUp con-2Q sisting of 2-acrylamido-2-methylpropanesulfonic acid, its salts and mixtures thereof in a solvent selected from the group consisting of water, alcohols and mixtures thereof, and polymerizing the polymerizable material in the solvent to form the conductive material.
Accosdingly, the electrodes of this invention essentially comprise electrical lead means contacting a mixture of polymerized 2-acrylamido-2-methylpropanesulfonic acid OT one of its salts with water andtor an alcohol.
Specific embodiments of the invention are described in the examples of the principal disclosure.
It is important to understand that all of ~he materials descTibed above by way of Example exhibit high conductivity. However, a conductivity improving constituent may be included in the electrically conductive ~5~ 7 member or substra~e. In particular, the addition of soluble, ionizable metal salts such as KCl and NaCl has an additional benefit in the electrical properties of sensing or monitoring type electrodes. Chloride salts are particularly prefeTred. While it is generally accepted ~hat salt addition to water soluble polymers improves conductivity, salt addition ~o the polymer impToves conductivity only slightly, not on an order of tenfold. Neverthe-less, it does provide unusually improved sensing properties as in EKG
testing for example.
Follo~ing are examples o electrodes in which salt has beer, added.
The same purging treatment and initiator were used as described above for E~ample 2. Thickness of the substrate materiai was about .100 inches.
89.3 grams of a 56% sodium salt solution of monomer were mixed with 7.7 grams of polyacrylic acid and 2.2 grams of 1% methylene-bis-acrylamide solution. To this solution~ 1.0 grams of NaCl was added. The resultant polymerized product consisted of cross-linked polymer blended with polyacrylic acid and showed enhanced electrical conductivity properties. In sensing applications, decreased motion artifacts were noted i.e., less background noise as opposed to the same formulation without NaCl.
EXAMPLE 2?
114 grams of a 56% sodium salt solution of monomer were mixed with 6 grams of glycerine and 2 milliliters of a 1% solution of me~hylene-bis-acrylamide. To this solution, 1 gram of NaCl was added. Again, the resultant polymerized product had enhanced properties as in Example 25 that were not present befoTe the addition of NaCl.
The polyacrylic acid added to the adhesiveness of the material and the methylene-bis-acrylamide caused cross-linking of the polymer.
~t~
Claims (37)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. An electrode including:
an adhesive, electrically conductive self-supporting gel member comprising as essential components thereof a polymer component selected from the group consisting of polymerized 2-acrylamido-2-methylpropanesulfon-ic acid, its salts, copolymers of said acid, copolymers of the salts of said acid, and mixtures thereof, and a second component selected from the group consisting of water, alcohols and mixtures thereof, sufficient relative amounts of the polymer component and the second component being included to provide adhesiveness and flexibility to the member, and electrical contact means connected to the conductive member.
an adhesive, electrically conductive self-supporting gel member comprising as essential components thereof a polymer component selected from the group consisting of polymerized 2-acrylamido-2-methylpropanesulfon-ic acid, its salts, copolymers of said acid, copolymers of the salts of said acid, and mixtures thereof, and a second component selected from the group consisting of water, alcohols and mixtures thereof, sufficient relative amounts of the polymer component and the second component being included to provide adhesiveness and flexibility to the member, and electrical contact means connected to the conductive member.
2. The electrode of Claim 1 wherein the alcohol is glycerol.
3. The electrode of Claim 1 wherein the alcohol is propylene glycol.
4. An electrode for establishing electrical connection to skin including:
an electrically conductive current distribution member;
electrical terminal means attached to the member, and a self-supporting gel substrate attached to the current distribu-tion member having adhesive, electrically conductive and flexible properties for adhering to the skin and including a polymer component selected from the group consisting of polymerized 2-acrylamido-2-methylpropanesulfonic acid, its salts, copolymers of said acid, copolymers of the salts of said acid, and mixtures thereof and a second component selected from the group consisting of water, alcohols and mixtures thereof, sufficient relative amounts of the polymer component and the second component being included to provide adhesiveness and flexibility to the member, the substrate being compatible with normal skin.
an electrically conductive current distribution member;
electrical terminal means attached to the member, and a self-supporting gel substrate attached to the current distribu-tion member having adhesive, electrically conductive and flexible properties for adhering to the skin and including a polymer component selected from the group consisting of polymerized 2-acrylamido-2-methylpropanesulfonic acid, its salts, copolymers of said acid, copolymers of the salts of said acid, and mixtures thereof and a second component selected from the group consisting of water, alcohols and mixtures thereof, sufficient relative amounts of the polymer component and the second component being included to provide adhesiveness and flexibility to the member, the substrate being compatible with normal skin.
5. An electrode according to Claim 4 wherein the substrate comprises about 25% to 65% by weight of said polymer component and about 75% to 35%
by weight of water.
by weight of water.
6. An electrode according to Claim 4 wherein the substrate comprises about 30% to 70% by weight of said polymer component and about 70% to 30%
by weight of the alcohol.
by weight of the alcohol.
7. An electrode according to Claim 4 wherein the substrate comprises about 30% to 70% by weight of said polymer component, about 30% to 70% by weight of water and about 30% to 70% by weight of the alcohol.
8. An electrode according to Claim 6 wherein the alcohol is glycol.
9. An electrode according to Claim 7 wherein the alcohol is glycerol.
10. An electrode according to Claim 4 including a polymer foam backing member overlying the current distribution member.
11. An electrode according to Claim 4 wherein the substrate is in sheet form, ranging in thickness from about .025 to .25 inches.
12. An electrode according to any of the preceding Claims 1, 2 or 3, wherein the electrically conductive member includes an additional thickening constituent.
13. An electrode according to any of the preceding claims 4, 5 or 6 wherein the substrate includes an additional thickening constituent.
14. An electrode according to any of the preceding Claims 7, 8 or 9 wherein the substrate includes an additional thickening constituent.
15. An electrode according to either of the preceding claims 10 or 11 wherein the substrate includes an additional thickening agent.
16. An electrode according to any of the preceding Claims l, 2 or 3 wherein the electrically conductive member includes an additional conductivity improving constituent.
17. An electrode according to any of the preceding claims 4, 5 or 6 wherein the substrate includes an additional conductivity improving con-stituent.
18. An electrode according to any of the preceding claims 7, 8 or 9 wherein the substrate includes an additional conductivity improving constituent.
19. An electrode according to either of the preceding claims 10 or 11 wherein the substrate includes an additional conductivity improving constituent.
20. An electrode according to any of the preceding claims l, 2 or 3, wherein the polymerization which forms the polymer component of the conduc-tive member was caused to take place simultaneously with the formation of the conductive member itself.
21. An electrode according to any of the preceding claims 4, 5 or 6 wherein the polymerization which forms the polymer component of the sub-strate was caused to take place simultaneously with the formation of the substrate itself.
22. An electrode according to any of the preceding claims 7, 8 or 9 wherein the polymerization which forms the polymer component of the sub-strate was caused to take place simultaneously with the formation of the substrate itself.
23. An electrode according to either of the preceding claims 10 or ll wherein the polymerization which forms the polymer component of the sub-strate was caused to take place simultaneously with the formation of the substrate itself.
24. An electrode according to claim 4 wherein the polymer component is a member selected from the group consisting of polymerised 2-acrylamido -2- methylpropanesulfonic acid, ammonium salt thereof, alkali metal salts thereof and mixtures thereof.
25. An electrode according to claim 4 wherein the polymer component is a copolymer formed by copolymerization of monomers consisting of (a) at least one member selected from the group consisting of 2-acrylamido-2-methylpropanesulfonic acid, its salts and mixtures thereof and (b) at least a member selected from the group consisting of acrylamido, N-vinylpyrollidone and acrylic acid.
CLAIMS SUPPORTED BY SUPPLEMENTARY DISCLOSURE:
CLAIMS SUPPORTED BY SUPPLEMENTARY DISCLOSURE:
26. An electrode according to any of the preceding claims 1, 2 or 3 wherein the electrically conductive member includes an additional con-ductivity improving constituent selected from suitable salts which are soluble in water, said alcohols or mixtures thereof.
27. An electrode according to any of the preceding claims 4, 5 or 6 wherein the substrate includes an additional conductivity improving constituent selected from suitable salts which are soluble in water, said alcohols or mixtures thereof.
28. An electrode according to any of the preceding claims 7, 8 or 9 wherein the substrate includes an additional conductivity improving constituent selected from suitable salts which are soluble in water, said alcohols or mixtures thereof.
29. An electrode according to either of claims 10 or 11 wherein the substrate includes an additional conductivity improving constituent selected from suitable salts which are soluble in water, said alcohols or mixtures thereof.
30. An electrode according to any of the preceding claims 1, 2 or 3 wherein the electrically conductive member includes an additional con-ductivity improving constituent selected from suitable chloride salts which are soluble in water, said alcohols or mixtures thereof.
31. An electrode according to any of the preceding claims 4, 5 or 6 wherein the substrate includes an additional conductivity improving constituent selected from suitable chloride salts which are soluble in water, said alcohols or mixtures thereof.
32. An electrode according to any of the preceding claims 7, 8 or 9 wherein the substrate includes an additional conductivity improving constituent selected from suitable chloride salts which are soluble in .
water, said alcohols or mixtures thereof.
water, said alcohols or mixtures thereof.
33. An electrode according to either of the preceding claims 10 or 11 wherein the substrate includes an additional conductivity improving constituent selected from suitable chloride salts which are soluble in water, said alcohols or mixtures thereof.
34. An electrode according to any of the preceding claims 1, 2 or 3 wherein the electrically conductive member includes an additional con-ductivity improving constituent consisting of NaCl.
35. An electrode according to any of the preceding claims 4, 5 or 6 wherein the substrate includes an additional conductivity improving constituent consisting of NaCl.
36. An electrode according to any of the preceding claims 7, 8 or 9 wherein the substrate includes an additional conductivity improving constituent consisting of NaCl.
37. An electrode according to either of the preceding claims 10 or 11 wherein the substrate includes an additional conductivity improving constituent consisting of NaCl.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US96848978A | 1978-12-11 | 1978-12-11 | |
| US968,489 | 1978-12-11 | ||
| US06/121,387 US4391278A (en) | 1978-12-11 | 1980-02-14 | Tape electrode |
| US121,387 | 1987-11-16 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1153427A true CA1153427A (en) | 1983-09-06 |
Family
ID=26819409
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000341593A Expired CA1153427A (en) | 1978-12-11 | 1979-12-10 | Tape electrode |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US4391278A (en) |
| CA (1) | CA1153427A (en) |
Families Citing this family (85)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU543967B2 (en) * | 1980-01-23 | 1985-05-09 | Minnesota Mining And Manufacturing Company | Conductive adhesive and biomedical electrode |
| US4524087A (en) * | 1980-01-23 | 1985-06-18 | Minnesota Mining And Manufacturing Company | Conductive adhesive and biomedical electrode |
| US4539996A (en) * | 1980-01-23 | 1985-09-10 | Minnesota Mining And Manufacturing Company | Conductive adhesive and biomedical electrode |
| JPS5933361Y2 (en) * | 1980-03-14 | 1984-09-18 | 日東電工株式会社 | electrode pad |
| US4768523A (en) * | 1981-04-29 | 1988-09-06 | Lifecore Biomedical, Inc. | Hydrogel adhesive |
| AU4198785A (en) * | 1984-05-07 | 1985-11-14 | Lloyd A. Ferreira | Conductive material and biomedical electrode |
| US4679564A (en) * | 1984-10-04 | 1987-07-14 | Sessions Robert W | Monitoring electrode attachable to a patient |
| DE3507301A1 (en) * | 1985-03-01 | 1986-09-04 | Arbo GmbH Medizin-Technologie, 38100 Braunschweig | BIOELECTRIC ELECTRODE |
| US4643193A (en) * | 1985-06-04 | 1987-02-17 | C. R. Bard, Inc. | ECG electrode with sensing element having a conductive coating in a pattern thereon |
| US4722354A (en) * | 1985-06-14 | 1988-02-02 | Jens Axelgaard | Electrical stimulation electrode |
| US4867166A (en) * | 1985-06-14 | 1989-09-19 | Jens Axelgaard | Electrical stimulation electrode |
| US4669479A (en) * | 1985-08-21 | 1987-06-02 | Spring Creek Institute, Inc. | Dry electrode system for detection of biopotentials |
| US4717378A (en) * | 1986-03-31 | 1988-01-05 | Medtronic, Inc. | Methods for detecting dehydration of a biomedical hydrogel |
| US4848353A (en) * | 1986-09-05 | 1989-07-18 | Minnesota Mining And Manufacturing Company | Electrically-conductive, pressure-sensitive adhesive and biomedical electrodes |
| US4736752A (en) * | 1986-11-28 | 1988-04-12 | Axelgaard Manufacturing Co., Ltd. | Transcutaneous medical electrode |
| US4893626A (en) * | 1986-12-11 | 1990-01-16 | Henley Ernest J | Electrode for electrotherapy, electrosurgery and monitoring |
| US5080646A (en) * | 1988-10-03 | 1992-01-14 | Alza Corporation | Membrane for electrotransport transdermal drug delivery |
| US4860754A (en) * | 1987-04-01 | 1989-08-29 | E. R. Squibb & Sons, Inc. | Electrically conductive adhesive materials |
| US4846185A (en) * | 1987-11-25 | 1989-07-11 | Minnesota Mining And Manufacturing Company | Bioelectrode having a galvanically active interfacing material |
| CA1326063C (en) * | 1988-01-04 | 1994-01-11 | David Rolf | Electrode with hydrogel matrix for medical use |
| US4870969A (en) * | 1988-09-16 | 1989-10-03 | Somatics, Inc. | Electrode application system and method for electroconvulsive therapy |
| US5496266A (en) * | 1990-04-30 | 1996-03-05 | Alza Corporation | Device and method of iontophoretic drug delivery |
| US4927408A (en) * | 1988-10-03 | 1990-05-22 | Alza Corporation | Electrotransport transdermal system |
| US5169382A (en) * | 1988-10-03 | 1992-12-08 | Alza Corporation | Membrane for electrotransport transdermal drug delivery |
| US5147296A (en) * | 1988-10-03 | 1992-09-15 | Alza Corporation | Membrane for electrotransport transdermal drug delivery |
| US4890622A (en) * | 1988-10-27 | 1990-01-02 | Ferrari Robert K | Disposable biomedical electrode |
| US4924880A (en) * | 1988-11-16 | 1990-05-15 | Sion Technology, Inc. | Dental anesthesia apparatus |
| US5234992A (en) * | 1989-02-09 | 1993-08-10 | Alza Corporation | Electrotransport adhesive |
| US5240995A (en) * | 1989-02-09 | 1993-08-31 | Alza Corporation | Electrotransport adhesive |
| FR2643271B1 (en) * | 1989-02-17 | 1991-05-24 | Gerard Ramond | CONTACT BLOCK FOR WALNUT IN ELECTRICALLY CONDUCTIVE MOLDING FOR ELECTRICAL TREATMENT OF SKIN FOR THERAPEUTIC OR AESTHETIC PURPOSE |
| US5167616A (en) * | 1989-12-14 | 1992-12-01 | Alza Corporation | Iontophoretic delivery method |
| US5124076A (en) * | 1990-01-19 | 1992-06-23 | Contour Electrodes, Inc. | Rapid, curing, electrically conductive adhesive |
| US5183599A (en) * | 1990-01-19 | 1993-02-02 | Smuckler Jack H | Rapid curing, electrically conductive adhesive |
| US5038797A (en) * | 1990-02-20 | 1991-08-13 | Romaine, Incorporated | Electrical stimulation treatment device and method of use |
| WO1991015260A1 (en) * | 1990-03-30 | 1991-10-17 | Alza Corporation | Device and method for iontophoretic drug delivery |
| DE69115471T2 (en) * | 1990-03-30 | 1996-05-02 | Alza Corp | DEVICE FOR IONTOPHORETIC ADMINISTRATION OF MEDICINES |
| US5121090A (en) * | 1990-04-09 | 1992-06-09 | Tektronix, Inc. | Balun providing dual balanced outputs |
| US5130139A (en) * | 1990-07-06 | 1992-07-14 | Alza Corporation | Reduction or prevention of skin irritation by drugs |
| US5160741A (en) * | 1990-07-06 | 1992-11-03 | Alza Corporation | Reduction or prevention of skin irritation by drugs |
| US5120545A (en) * | 1990-08-03 | 1992-06-09 | Alza Corporation | Reduction or prevention of sensitization to drugs |
| US5149539A (en) * | 1990-08-03 | 1992-09-22 | Alza Corporation | Reduction or prevention of sensitization to drugs |
| US5173302A (en) * | 1990-09-28 | 1992-12-22 | Medtronic, Inc. | Hydrophilic pressure sensitive adhesive for topical administration of hydrophobic drugs |
| DE4039780C1 (en) * | 1990-12-13 | 1992-08-06 | Lohmann Gmbh & Co Kg, 5450 Neuwied, De | |
| WO1993000857A1 (en) * | 1991-07-12 | 1993-01-21 | Ludlow Corporation | Biomedical electrode |
| AU652494B2 (en) * | 1991-11-15 | 1994-08-25 | Minnesota Mining And Manufacturing Company | Solid state conductive polymer compositions, biomedical electrodes containing such compositions, and method of preparing same |
| DE4238263A1 (en) * | 1991-11-15 | 1993-05-19 | Minnesota Mining & Mfg | Adhesive comprising hydrogel and crosslinked polyvinyl:lactam - is used in electrodes for biomedical application providing low impedance and good mechanical properties when water and/or moisture is absorbed from skin |
| US5184620A (en) * | 1991-12-26 | 1993-02-09 | Marquette Electronics, Inc. | Method of using a multiple electrode pad assembly |
| US5264249A (en) * | 1992-03-20 | 1993-11-23 | Medtronic, Inc. | Method for making a conductive coated product |
| US5330526A (en) * | 1992-05-01 | 1994-07-19 | Zmd Corporation | Combined defibrillation and pacing electrode |
| US5407368A (en) * | 1992-12-15 | 1995-04-18 | Minnesota Mining And Manufacturing Company | Electrode connector |
| US5454739A (en) * | 1992-12-15 | 1995-10-03 | Minnesota Mining And Manufacturing Company | Electrode connector |
| US5298017A (en) * | 1992-12-29 | 1994-03-29 | Alza Corporation | Layered electrotransport drug delivery system |
| US5394877A (en) * | 1993-04-01 | 1995-03-07 | Axon Medical, Inc. | Ultrasound medical diagnostic device having a coupling medium providing self-adherence to a patient |
| US5506059A (en) * | 1993-05-14 | 1996-04-09 | Minnesota Mining And Manufacturing Company | Metallic films and articles using same |
| US5650060A (en) * | 1994-01-28 | 1997-07-22 | Minnesota Mining And Manufacturing Company | Ionically conductive agent, system for cathodic protection of galvanically active metals, and method and apparatus for using same |
| US5868136A (en) * | 1996-02-20 | 1999-02-09 | Axelgaard Manufacturing Co. Ltd. | Medical electrode |
| US6800278B1 (en) | 1996-10-28 | 2004-10-05 | Ballard Medical Products, Inc. | Inherently antimicrobial quaternary amine hydrogel wound dressings |
| US5800685A (en) * | 1996-10-28 | 1998-09-01 | Cardiotronics Systems, Inc. | Electrically conductive adhesive hydrogels |
| US5830136A (en) * | 1996-10-31 | 1998-11-03 | Nellcor Puritan Bennett Incorporated | Gel pad optical sensor |
| US6148233A (en) | 1997-03-07 | 2000-11-14 | Cardiac Science, Inc. | Defibrillation system having segmented electrodes |
| US6163720A (en) * | 1997-12-18 | 2000-12-19 | Alza Corporation | Layered rate controlling membranes for use in an electrotransport device |
| ATE406134T1 (en) * | 1999-02-08 | 2008-09-15 | Axelgaard Mfg Co Ltd | MEDICAL ELECTRODE |
| US6731965B2 (en) * | 2001-06-20 | 2004-05-04 | 3M Innovative Properties Company | Corrosion prevention in biomedical electrodes |
| GB0211529D0 (en) * | 2002-05-20 | 2002-06-26 | First Water Ltd | Ionic hydrogels with low aqueous fluid absorption |
| WO2004057057A1 (en) * | 2002-12-23 | 2004-07-08 | Council Of Scientific And Industrial Research | Process for manufacture of proton conductive polymer gel useful as backfill for sacrificial and impressed current anode systems |
| US7045559B2 (en) * | 2003-12-18 | 2006-05-16 | Kimberly-Clark Worldwide, Inc. | Electrically conductive adhesive hydrogels with solubilizer |
| US20050136023A1 (en) * | 2003-12-18 | 2005-06-23 | Kimberly-Clark Worldwide, Inc. | Electrically conductive adhesive hydrogels with a thermally activated chemical initiator |
| US20050136077A1 (en) * | 2003-12-18 | 2005-06-23 | Kimberly-Clark Worldwide, Inc. | Electrically conductive adhesive hydrogels with two initiators |
| GB0403510D0 (en) * | 2004-02-18 | 2004-03-24 | Mantra Internat Ltd | Bioadhesive compositions and their use in medical electrodes |
| US7066935B2 (en) * | 2004-04-30 | 2006-06-27 | Medtronic, Inc. | Ion eluting tuna device |
| US7668604B2 (en) * | 2004-06-16 | 2010-02-23 | Conmed Corporation | Packaging for medical pads and electrodes |
| US20070048249A1 (en) | 2005-08-24 | 2007-03-01 | Purdue Research Foundation | Hydrophilized bactericidal polymers |
| US7678716B2 (en) * | 2006-08-31 | 2010-03-16 | Kimberly-Clark Worldwide, Inc. | Hydrogel-web composites for thermal energy transfer applications and methods of making the same |
| US7816412B2 (en) * | 2007-02-23 | 2010-10-19 | Conmed Corporation | Electrically conductive hydrogels |
| WO2008150867A2 (en) | 2007-05-29 | 2008-12-11 | Innova Materials, Llc | Surfaces having particles and related methods |
| WO2009006397A2 (en) * | 2007-06-28 | 2009-01-08 | University Of Pittsburgh-Of The Commonwealth System Of Higher Education | Electrode systems and methods comprising a hydrophilic swollen polymer |
| US8275441B2 (en) * | 2007-11-02 | 2012-09-25 | Tyco Healthcare Group Lp | Electrodes possessing change indicator |
| US7774070B2 (en) * | 2008-01-10 | 2010-08-10 | Hill Laboratories Company | Medical electrode assembly for electrotherapy and phototherapy treatment |
| CA2734864A1 (en) * | 2008-08-21 | 2010-02-25 | Innova Dynamics, Inc. | Enhanced surfaces, coatings, and related methods |
| CN103155174B (en) | 2010-08-07 | 2017-06-23 | 宸鸿科技控股有限公司 | The device assembly of the additive with surface insertion and the manufacture method of correlation |
| WO2016080082A1 (en) * | 2014-11-17 | 2016-05-26 | 積水化成品工業株式会社 | Pad for electrodes |
| WO2018116161A1 (en) | 2016-12-19 | 2018-06-28 | Intento Sa | Electrode and connector assemblies for non-invasive transcutaneous electrical stimulation and biological signal sensing |
| US20180340046A1 (en) | 2017-05-27 | 2018-11-29 | Poly Group LLC | Dispersible antimicrobial complex and coatings therefrom |
| EP3638740A1 (en) | 2017-06-16 | 2020-04-22 | Poly Group LLC | Polymeric antimicrobial surfactant |
| CN107384229B (en) * | 2017-07-13 | 2021-12-17 | 东南大学 | Method for highly attaching flexible device to skin surface |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4136078A (en) * | 1971-05-21 | 1979-01-23 | The Lubrizol Corporation | Compositions comprising a plasticizer and an n-sulfohydrocarbon-substituted acrylamide polymer |
| US3946730A (en) * | 1972-01-21 | 1976-03-30 | Ndm Corporation | Biomedical electrode assembly |
| US3989050A (en) * | 1972-09-19 | 1976-11-02 | Gilbert Buchalter | Process for utilizing certain gel compositions for electrical stimulation |
| US3972329A (en) * | 1974-11-25 | 1976-08-03 | Kaufman John George | Body electrode for electro-medical use |
| US4094822A (en) * | 1974-12-26 | 1978-06-13 | Kater John A R | Bio-event electrode material |
| US3993049A (en) * | 1974-12-26 | 1976-11-23 | Kater John A R | Electrodes and materials therefor |
| US4125110A (en) * | 1975-11-25 | 1978-11-14 | Hymes Alan C | Monitoring and stimulation electrode |
| US4066078A (en) * | 1976-02-05 | 1978-01-03 | Johnson & Johnson | Disposable electrode |
| US4273135A (en) * | 1977-08-19 | 1981-06-16 | Minnesota Mining And Manufacturing Company | Biomedical electrode |
| US4174152A (en) * | 1978-02-13 | 1979-11-13 | American Cyanamid Company | Electrochromic devices with polymeric electrolytes |
-
1979
- 1979-12-10 CA CA000341593A patent/CA1153427A/en not_active Expired
-
1980
- 1980-02-14 US US06/121,387 patent/US4391278A/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| US4391278A (en) | 1983-07-05 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1153427A (en) | Tape electrode | |
| US4581821A (en) | Method of preparing tape electrode | |
| EP0012402B1 (en) | Tape electrode | |
| CA1181582A (en) | Electrically conductive compositions and electrodes utilizing same | |
| US7540979B2 (en) | Method for making a medical electrode polymer | |
| US5868136A (en) | Medical electrode | |
| US4777954A (en) | Conductive adhesive medical electrode assemblies | |
| US5800685A (en) | Electrically conductive adhesive hydrogels | |
| EP0255241B1 (en) | Medical electrode | |
| US4860754A (en) | Electrically conductive adhesive materials | |
| US20070293751A1 (en) | Medical electrode | |
| EP0564448A1 (en) | Non-stringy adhesive hydrophilic gels | |
| WO1981002097A1 (en) | Conductive adhesive and biomedical electrode | |
| JP2003501545A (en) | Conductive pressure-sensitive adhesive having hot-melt properties and biological electrode using the same | |
| US6115625A (en) | Medical electrode | |
| JPH08155040A (en) | Conductive tacky adhesive and electrode pad formed by using the same | |
| JP3429198B2 (en) | Self-crosslinkable polymer copolymer solution, polymer gel, and method for producing the same | |
| JPS61137539A (en) | Medical conductive pressure-sensitive agent and skin electrode using the same | |
| EP1158896B1 (en) | Medical electrode | |
| JPH0232892B2 (en) | ||
| WO2024070988A1 (en) | Electrode pad | |
| JPH0947437A (en) | Electrode for organism |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |