JPH04132536A - Biomedical electrode - Google Patents

Abstract

PURPOSE:To obtain an electrode with limited variations and stable with limited change in handling by providing a metal conducting layer at a part contacting a connection device on a carbonaceous conducting layer while the connection device and the metal layer is kept from contacting a conductive pressure- sensitive adhesive directly. CONSTITUTION:A conducting ink is applied on one surface of a PET film by screen printing and dried to obtain a laminate of the PET and a conducting layer 2. A conducting silver ink is further printed circular on the laminate and dried. A hole is made at the center of the silver printed part, a snap having brass plated with nickel is inserted into the hole and a vinyl tape (black) is stuck form the side of the conducting layer to fix. Then, a conducting water- containing gel 3 internally reinforced with a polyester net prepared separately is applied on the work and a peeling film of PET treated non-adhesive with a releasing agent is applied thereon. The laminate thus obtained is cut in square containing the snap to form an electrode. Thus, an electrode is obtained which is low in impedance while being stable with limited variations.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a biomedical electrode made of a skin-compatible conductive adhesive and equipped with a connector such as a snap.

<Prior art> As biomedical electrodes, conventional methods include an electrode plate, a means for electrically connecting the electrode plate and a hood, and a conductive cream or skin for improving the electrical conductivity between the skin and the electrode plate. Conductive adhesives that are compliant with

Silver-silver chloride electrodes are conventionally known as particularly preferable electrode plates, but metals such as aluminum can also be used. Further, as the conductive adhesive, various hydrogels in which an electrolyte is dissolved are used. Metal snaps are used as means for electrically connecting the electrode plate and the cord so that they can be easily attached and detached.

<Problems to be Solved by the Invention> However, if a metal electrode plate, a connector such as a metal snap, and a hydrous gel in which an electrolyte is dissolved are left in contact with each other for a long time, the electrode plate or the connector will corrode. There was a problem. Although the above-mentioned problems can be greatly improved by using a conductive carbonaceous coated body as an electrode plate, it is still insufficient.

This corrosion problem is overcome by breaking contact between the metal connector and the electrolyte-containing hydrogel.

Conventionally, as shown in FIG. 2, the connector and the hydrous gel were arranged at different positions so as not to connect with each other. However, if the position of the adhesive part and the connector are misaligned, the resistance against twisting of the connection cord is weak (there was a problem that the conductor could easily come off).Also, the snap was placed inside the hydrogel in the plan view. By pasting an insulating film on the soil of the snap as shown in Figure 3 and cutting off contact with the hydrous gel, the corrosion problem can be solved without shifting the position of the hydrous gel and the connecting tool.However, this method Another problem arises in that electrical conduction between the snap and the electrode plate made of carbonaceous material is not reliable, and electricity may or may not flow due to slight misalignment of the connector.

<Means for Solving the Problems> The above problems are solved by the electrode of the present invention, that is, as shown in FIG. An electrically conductive carbonaceous conductive layer made of carbon and a binder, a conductive layer adhesive layer made of a water-containing gel with good skin adaptability, and a carbonaceous conductive layer and an external cord. A biomedical electrode consisting of a metal connecting device that penetrates a film provided for electrical connection with a carbonaceous conductive layer and has a head facing the non-conductive side of the film. This is achieved by providing a conductive layer made of metal on the part that comes into contact with the connector, and partially adhering a film to isolate the connector and the metal layer so that they do not come into direct contact with the conductive adhesive, and further separating the metal from the metal. The conductive layer is made of silver, aluminum, or nickel, the connection is a snap, and the film separating the conductive adhesive and metal is substantially the same color as the carbonaceous layer. , more preferably achieved.

<Function> The present invention has a film made of a non-conductive material provided with an electrically conductive carbonaceous material on one side, and a connector such as a snap that controls conduction to the outside and an adhesive that controls conduction with the skin. It has a structure. Non-conductive films include polyethylene terephthalate (PET), polyvinyl chloride (PVC), polyethylene, and polypropylene, all of which can be used, but there are issues with film strength, ease of conductive ink printing process, etc. From P
ET is preferred. Conductive ink is known to be a mixture of conductive carbon particles, in some cases silver particles, and binder and a medium, and is coated onto the non-conductive film mentioned above by a method such as screen printing. It can be a laminate. As the connector, a metal such as copper or brass, or a metal plated with nickel, silver, etc., is preferably used, and the shape of the connector is appropriately selected as required. In particular, snaps are a preferred form because they can be easily attached and detached. The snap is attached with its head facing the non-conductive side of the film and its collar facing the conductive adhesive side. At this time, the installation may be done by caulking. Since there is a risk of deformation of the film, it is also possible to simply insert it and press it with a film.

The first feature of the electrode of the present invention is that a film is interposed between the connector and the conductive adhesive in order to avoid direct contact between the connector and the conductive hydrogel adhesive. The film is there to prevent the connector from coming into contact with the conductive hydrogel adhesive, so it does not need to be conductive, but it does need to be non-corrosive. It is preferable to attach it to a conductive film with adhesive to ensure isolation.

This film may be of any material, but PVC, PET, etc. are used. This film needs to have a sufficiently large area for isolation, but if it is too large, problems will arise in conductive performance, so it is preferable not to make it unnecessarily large. From the viewpoint of appearance, it is preferable that the color of this film be the same color as the conductive layer (substantially black).

A second feature of the electrode of the present invention is that a conductive metal layer is provided at the portion of the carbonaceous conductive layer that comes into contact with the connector. This metal layer can be provided by printing a metal ink such as silver paste on the carbonaceous layer or partially vapor depositing metal, and by providing this layer, the carbonaceous conductive Electrical conduction between the layer and the connector is ensured. This is especially dangerous when an electric signal is sent from the outside to the human body, such as a low-frequency treatment device, and continuity is uncertain, as there is a risk that the current may suddenly turn on during handling from a state where no electricity is flowing. be. Although any conductive adhesive can be used, it is preferable to use a hydrogel in which an electrolyte such as common salt is dissolved. In addition, the conductive adhesive may be made in advance in a sheet form elsewhere and attached to the above-mentioned material, or a precursor of the conductive adhesive may be placed on the aforementioned laminate and the adhesive material will react with it. You may try to change it.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

<Example 1> Conductive ink JEF-114 manufactured by Nippon Acheson Co., Ltd. was screen printed on one side of a 75 μm thick PET film using a lOO mesh screen, and dried to form a PET film.
A laminate of T and a conductive layer was obtained. The thickness of the conductive paint layer was approximately 5 microns, and the surface resistivity was 120 Ω/hole. On top of this conductive ink layer, a conductive silver ink (ED-42 manufactured by Acheson Japan) is applied to a diameter of 8■■.
7SS) was printed in a circular shape and dried at 75°C for 30 minutes. Drill a hole with a diameter of 4ml in the center of this silver printed part,
Insert a snap made of nickel-plated brass (Gondola Kogyo 111NT-7 lower model (SIZE7-m, ='ykel) with the head facing the non-conductive side of the film laminate and place it on the conductive layer side. Karakamoto Chemical Vinyl Tape (Black)
It was pasted and fixed. On top of this, a conductive water-containing gel with a thickness of 2 lines reinforced with a polyester net was pasted on the inside that was prepared separately, and a 75 μm thick PET release film treated with a release agent to make it non-adhesive was pasted on top of it. Ta. This laminate was cut into a 3 cs x 3 cm square including a snap to make a biomedical electrode.

At this time, the snap position was set so that the center of the snap was located at a position 8 cm from the corner of the rectangle. The release film of this electrode was peeled off, the electrode was attached to a stainless steel plate, and an AC voltage of IkHz, IV PP was applied between the snap and the stainless steel plate, and the impedance was measured to be 35Ω. When 50 electrodes with an open configuration were prepared and their impedances were measured in the same manner, the average value was 38Ω and the standard deviation was 3Ω, and there were no electrodes with significantly large impedances. Furthermore, although the snap portion was repeatedly attached and detached 100 times, no abnormally high impedance was observed. This electrode was left in an atmosphere of 60° C. and 55% RH for 30 hours (1 hour), but no change in appearance such as corrosion was observed.

<Example 2> Conductive paint containing nickel instead of silver ink as the conductive ink in Example 1 (Toa Paint Co., Ltd.)
The biological material was prepared in exactly the same way, except that Doorlex (manufactured by Doorex = 5000) was applied with a brush and allowed to dry, black polyester tape made by Building Block Chemical was used instead of vinyl tape made by Building Block Chemical, and the position of the snap was placed in the center. Created medical electrodes. The snap cover film was not clearly visible from the surface and had a good appearance. Example 1
When the impedance was measured in the same manner as above, the average value was 45Ω, the standard deviation was 4Ω, and the stability was also good.

<Comparative Example> Fifty electrodes were made in the same manner as in Example 1 except that silver ink having a diameter of 8 mm was not printed.

When I measured the impedance of these, three of them were I
It was more than MΩ, and 7 pieces were more than 1Ω. Also lk
Even when the resistance was less than Ω, the average value was 180Ω with a standard deviation of 20Ω, which was a large value. Further, even if the impedance shows an average value, when the snap is repeatedly attached and detached, the impedance value changes greatly and sometimes exceeds IMΩ.

<Effects> As is clear from the above Examples and Comparative Examples, the electrode of the present invention has low impedance and little variation, and is a stable electrode with little change during handling. Also, there is no change in appearance or performance due to corrosion such as snaps. In particular, when a black adhesive tape is used as the cover film, the appearance is good because it has the same color as the carbonaceous conductive layer. Furthermore, since the adhesive layer and the connector are located close to each other, the fit to the skin is also good.

[Brief explanation of the drawing]

FIG. 1 is a plan view and a sectional view showing an example of the electrode of the present invention, FIG. 2 is a plan view and a sectional view showing a conventional electrode, and FIG. 3 is a plan view of a partially improved electrode. and a cross-sectional view. In each drawing, 1 is a base film, 2 is a conductive layer made of silver, 2 is a layer of conductive carbon, 3 is a layer of conductive adhesive made of hydrogel, and 4 is a conductive adhesive tape based on aluminum. , 4° is insulating adhesive tape, 5 is Suna・
A connector is a knob, 6 is a gold rR (silver) conductive layer, and 7 is a release film.

Claims (4)

[Claims] (1) A film made of a substantially non-conductive material, an electrically conductive carbonaceous conductive layer made of carbon and a binder provided on one side of the film, and a skin provided on the carbonaceous conductive layer. A conductive adhesive layer made of a flexible hydrous gel and a film provided for electrically connecting the carbonaceous conductive layer and an external cord are penetrated and the external connection is connected to the non-conductive layer of the film. A biomedical electrode consisting of a metal connector facing toward the side, wherein a conductive layer made of metal is provided on a carbonaceous conductive layer at a portion that contacts the connector, and the connector and the conductive layer made of metal are provided. A biomedical electrode characterized in that it is isolated by partially adhering a film to prevent direct contact with a conductive adhesive. (2) The biomedical electrode according to claim 1, wherein the metal in the conductive layer is silver, aluminum, copper, or nickel. (3) The biomedical electrode according to claim 1 or 2, wherein the connector is a snap. (4) The biomedical electrode according to any one of claims 1 to 3, wherein the film separating the conductive adhesive and the metal has substantially the same color as the carbonaceous layer.