JPH05200007A - Pad for living body electrode - Google Patents

Abstract

PURPOSE:To provide a pad for a living body electrode excellent in a fixing property to the living body electrode and operability. CONSTITUTION:A pad for a living body electrode is composed of a hydrous gel layer 2 formed on the upper surface of a base member 1, an effusion hydrous gel layer 3 formed on the opposed lower surface and connected electrically to the hydrous gel layer 2 and an adhesive layer 4 formed on the vicinity of the effusion hydrous gel layer 3. The adhesive layer 4 is formed to have nearly same thickness as that of the effusion hydrous gel layer 3. Thus, the pad makes firm intimate contact with and sure fixation to the living body electrode to provide excellent reliability on an electric connection. Also, a separator is easily stripped to improve the operability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a biomedical electrode pad that is fixed to the surface of a living body and electrically connects the living body to various electric devices outside the living body.

[0002]

2. Description of the Related Art Conventionally, a device that introduces an electric signal such as a weak current due to a low frequency or an electromagnetic wave due to a high frequency into the body from the outside of the living body to promote blood flow, and mainly treats the massage effect, etc. There are known devices such as an electrocardiograph, an electroencephalograph, and an electromyography that take out electrical signals from the living body for treatment, and take out electrical signals from the living body for measurement. Is used. Such a bioelectrode pad is required to have conductivity, as well as adhesion to a living body surface and skin followability, and in recent years, a pad using a hydrous gel base material has been adopted.

The pad using the gel base material has a relatively thick gel layer formed on both surfaces of a base material such as a non-woven fabric in order to improve the adhesion to the living body surface. However, if the gel layer fixed to the biomedical electrode is too thick, the signal / noise ratio (S / N ratio) deteriorates, which may adversely affect the conductivity. In addition, when used as a bioelectrode of a measuring device such as a diagnostic device, accurate measurement may not be possible.

Therefore, if a gel layer is formed on one surface of the base material and the gel layer is exuded to the other surface through the voids of the base material to form a bioelectrode pad, the above-mentioned problem of conductivity is solved. The gel layer exuding on the other surface of the base material is too thin to obtain the adhesion to the bioelectrode, and the bioelectrode pad cannot be sufficiently fixed.

On the other hand, the gel layer is covered with a separator in order to prevent contamination from the outside air. However, if this separator is the same size as the gel layer, or if the gel layer is provided with an adhesive layer that reinforces the adhesion to the biological surface, the separator is difficult to peel off when using the bioelectrode pad, There is an inconvenience that it is inferior in nature.

[0006]

DISCLOSURE OF THE INVENTION The present invention solves the problems of the above-mentioned conventional bioelectrode pads, and an object thereof is to provide a bioelectrode pad excellent in fixability and operability to the bioelectrode. To do.

[0007]

Means for Solving the Problems As a result of intensive studies for achieving the above-mentioned object, the present inventors have found that when a pressure-sensitive adhesive layer is formed on the peripheral portion on the back surface side of a base material, the adhesion between a living body and a biological electrode The present invention has been completed based on the finding that the property is improved, the diffusion of the hydrous gel exuding to the back surface side of the substrate can be prevented, and a thick gel layer can be formed between the pressure-sensitive adhesive layers.

That is, the bioelectrode pad of the present invention is
Hydrous gel layer formed in the central portion of the upper surface of the substrate, exuded hydrous gel layer conducting with the hydrous gel layer formed in the central portion of the lower surface facing the substrate, and the exuded hydrous gel layer It is characterized in that it is composed of a pressure-sensitive adhesive layer formed on a peripheral portion and a separator having at least the same size as that of the base material covering the surfaces of these exposed layers.

To explain the present invention in more detail, the base material used for the bioelectrode pad is not particularly limited in its material, and is a woven fabric made of polyester, rayon, polypropylene, nylon, vinylon, cotton, cotton, etc., Non-woven fabric,
A cloth base material such as a knitted cloth or a net-like (net-like) cloth is used.
In such a substrate, since the hydrous gel surely exudes to the back surface through the inside and conducts, the average diameter of the effective voids is 0.1
mm or more, particularly about 0.1 to 5 mm is preferable, and a net-shaped cloth is preferably used. Since the size of the bioelectrode pad is usually about 5 to 80 cm, the basis weight of the hydrous gel is 10 to 100 g / m ² , preferably about 30 to 70 g / m ² .

In the present invention, the water-containing gel layer formed on one surface of the above-mentioned cloth base material is interposed between the bioelectrode and the biosurface so as to be electrically conducted, and has adhesiveness to the biosurface. Those having are preferable. Examples of the base material for forming such a gel layer include karaya gum, gelatin, polyacrylic acid or a salt thereof, other various water-soluble or water-dispersible acrylic polymers, polyacrylamide, polyvinyl alcohol, carboxymethyl cellulose, polyurethane and the like. And water-soluble or water-dispersible polymers thereof. It is preferable to add a polyhydric alcohol such as glycerin, water, an electrolyte, etc. to these base materials, if necessary, and appropriately apply a crosslinking means. Particularly preferable base material is polyacrylic acid or polyacrylic acid salt mixed with glycerin, water, etc. from the viewpoints of quality stability, skin adhesion (adhesiveness), conductivity, shape retention, etc. An example is a hydrogel-like base material obtained by applying a crosslinking means.

In the present invention, the water content of the hydrous gel layer is usually 5 to 50% by weight, preferably 10 to 30% by weight.
The degree is appropriate. Further, polyhydric alcohols such as glycerin, polyethylene glycol, and polypropylene glycol are added in an amount of 5 to 70 to impart skin adhesiveness and water retention.
It is desirable that the content is about 20% by weight, preferably about 20 to 50% by weight.

The thickness of the hydrous gel layer is 0.1 to 3.0 mm, preferably 0 on the side in contact with the living body surface, considering that skin conformability (flexibility) and uniform conductivity can be obtained. It is desirable to form it with a thickness of about 0.5 to 2.0 mm. The water-containing gel layer is preferably provided in the central portion of the base material, but it may be unevenly distributed at the end portion of the base material in consideration of the size, material, shape and the like of the base material.

The hydrous gel layer is formed on the substrate or the separator by a method such as a roll coater, a reverse coater, a gravure printer, a doctor blade and a bar coater.

The water-containing gel layer is provided on one surface of the base material, and the water-containing gel permeates the base material and exudes to the other surface side to conduct electricity. A pressure-sensitive adhesive layer for reinforcing the adhesion to the bioelectrode is formed on the base material near the exuded hydrous gel layer. The pressure-sensitive adhesive layer preferably surrounds the periphery of the exuded hydrous gel layer, but may be formed by being scattered around the periphery.

As such a pressure-sensitive adhesive layer, a known pressure-sensitive adhesive having excellent adhesion to a bioelectrode such as an acrylic type, a rubber type, a silicone type or a vinyl ether type can be used, and the base material has a thickness of about 20 to 200 μm. It is formed with thickness.

Further, since the surface of the hydrous gel layer exposed on both sides (front and back) of the substrate is coated with a separator to prevent contamination from the outside air, the exuding gel layer is the pressure-sensitive adhesive layer. As spacers (thickness forming material), which exudes between the base material and the separator (gap), and has substantially the same thickness as the pressure-sensitive adhesive layer. Therefore, the pressure-sensitive adhesive is appropriately selected within the above range depending on the desired thickness of the exuding gel layer.

The above-mentioned pressure-sensitive adhesive layer can be formed by using a known coating means, but when it is formed by various pattern coating using a gravure printer, the contact area with the separator is reduced and the separator is peeled off. It is preferable because it becomes easy. As the pattern shape, for example, a lattice pattern, a polka dot pattern, a striped pattern, a wave pattern, or the like can be used.

In the bioelectrode pad of the present invention, the size of the separator covering the exposed hydrous gel layer is
Preferably the same as or more than the substrate is used. When the size of the separator used is the same as or smaller than that of the base material, it is desirable to form notches of various shapes in the separator.

A straight line is a typical cut shape for the separator, but is a perforated shape, a one-dot chain line shape,
A wavy line shape, a sawtooth shape, or the like can be used. By using such a separator, when the bioelectrode pad of the present invention is attached and fixed to the bioelectrode, the separator can be easily peeled off and the operability is improved.

As the separator to be used, there can be used a plastic film or paper which is coated with a silicone resin or a fluorine-containing resin on one side or both sides and subjected to a peeling treatment.

When the biomedical electrode pad of the present invention does not have self-supporting property, that is, when it is so-called stiff and its handling property is not sufficient, a frame-shaped plastic sheet is used as an adhesive or a frame-shaped plastic sheet on the surface of the base material before gel layer formation. It is preferable to attach it by means of heat fusion. Examples of the material for such a frame material include plastic sheets such as polyvinyl chloride, polyester resin, polyolefin resin, polyurethane resin, and silicone resin, non-woven fabrics such as polyester resin, rayon, and polyolefin resin, and polyurethane resin and polyethylene. Examples thereof include foams and papers, and those having appropriate flexibility are used. The frame material preferably has a thickness of about 0.05 to 1 mm from the viewpoint of handleability.

In the bioelectrode pad of the present invention, for example, a separator having a hydrous gel layer formed on a separator, the hydrous gel layer is attached to one surface of a substrate, and then a pressure-sensitive adhesive layer is formed on the peripheral portion of the separator. It is manufactured by a method of laminating on the back surface of the substrate, a hydrous gel layer on the upper surface of the substrate, a pressure-sensitive adhesive layer separately or simultaneously on the peripheral portion of the lower surface, and a method of coating a separator on each surface. ..

[0023]

According to the structure of the present invention, a thick film exuding hydrous gel is formed on the lower surface of the base material of the bioelectrode pad with the adhesive layer serving as a spacer and conducting with the hydrous gel layer on the upper surface. Synergistic with the adhesive force of the agent layer, the fixability to the bioelectrode is improved. Moreover, since the pressure-sensitive adhesive layer is formed by pattern coating, the contact area with the separator is reduced, and the peelability of the separator is improved. Further, since the notch is formed in the separator, the separator's peelability is improved.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The bioelectrode pad of the present invention will be specifically described below with reference to the drawings showing one embodiment. FIG. 1 is a cross-sectional view showing the structure of the bioelectrode pad of the present invention. In the figure, A is a bioelectrode pad, including a base material 1, water-containing gel layers 2 and 3 formed on both upper and lower surfaces thereof, and an adhesive layer 4 formed on the peripheral portion of the water-containing gel layer 3 on the lower surface. The water-containing gel layer 2, the water-containing gel layer 3 and the pressure-sensitive adhesive layer 4 are coated with separators 5a and 5b, respectively.

The substrate 1 is made of a polyester cloth, and is obtained by partially crosslinking a composition comprising 20 parts of sodium polyacrylate, 40 parts of glycerin and 40 parts of water on the upper surface thereof with an epoxy crosslinking agent. Water-containing gel layer 2 was applied with a knife coater to a thickness of 2 mm.
Is formed.

The exuded water-containing gel layer 3 is formed by exuding the water-containing gel layer 2 from the polyester cloth substrate 1 and is electrically connected to the water-containing gel layer 2. At the peripheral portion of the lower surface of the base material 1, a pressure-sensitive adhesive layer 4 is formed by applying a hot-melt pressure-sensitive adhesive with a gravure printer in a wavy pattern to a thickness of 40 μm. Therefore, in the hydrous gel layer 2, the exudative hydrous gel layer 3 having the same thickness as the adhesive layer 4 was formed between the adhesive layers 4 and 4 by using the exudative adhesive layer 4 as a spacer.

The separators 5a and 5b are of the same size as the base material 1 and are made of a polyester film coated with a silicone resin. The hydrous gel layer 2, the exudative hydrous gel layer 3 and the adhesive layer 4 are used. The surface of each is covered. A linear cut 6 is formed in the center of the separator 5b.

According to the bioelectrode pad A having the above structure,
Since the pressure-sensitive adhesive layer 4 is formed on the peripheral portion of the exuding hydrous gel layer 3 to be bonded to the living body surface, the pad A can be firmly adhered and fixed to the living body electrode. In addition, the hydrous gel layer 2
Is covered with a separator 5a, and the surfaces of the exuded water-containing gel layer 3 and the pressure-sensitive adhesive layer 4 are covered with a separator 5b, respectively, so that the surfaces of the water-containing gel layers 2 and 3 can be protected from contamination of the outside air. In addition, the separator 5a is the hydrous gel layer 2
On the other hand, since a linear cut is formed in the separator 5b, when the pad A is attached and fixed to the biomedical electrode, the separators 5a and 5b can be easily peeled off and its operability is improved. improves.

FIG. 2 shows another embodiment of the present invention and is a partially enlarged view showing the shape of the pressure-sensitive adhesive layer. In the figure, (a) is a lattice pattern, (b) is a polka dot pattern,
(C) shows the striped pattern, and (d) shows the wavy pattern of the adhesive layer 4.

FIG. 3 shows another embodiment of the present invention and is a plan view showing a cut shape formed in the separator. In the figure, (a) shows perforations, (b) shows one-dot chain lines, (c) shows wavy lines, and (d) shows sawtooth-shaped cuts 6.

[0031]

EFFECT OF THE INVENTION Since the bioelectrode pad of the present invention can be firmly adhered and firmly fixed to the bioelectrode, excellent electrical connection reliability can be obtained. Further, when the biomedical electrode pad is used, the separator can be easily peeled off from the pad, and its handleability is improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a bioelectrode pad of the present invention.

FIG. 2 is a partially enlarged view showing a pattern shape of an adhesive layer showing another embodiment of the present invention.

FIG. 3 is a plan view showing a cut shape formed in a separator showing another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base material 2 Hydrous gel layer 3 Exudative hydrous gel layer 4 Adhesive layers 5a, 5b Separator 6 Notch part A Pad for bioelectrode

Claims (4)

[Claims] 1. A hydrous gel layer formed on the upper surface of a substrate,
It is composed of an exudative hydrous gel layer that is in conduction with the hydrous gel layer formed on the lower surface facing this, and an adhesive layer formed near the exudative hydrous gel layer, and the adhesive layer exudes A bioelectrode pad, which is formed to have substantially the same thickness as the hydrous gel layer. 2. The bioelectrode pad according to claim 1, wherein the pressure-sensitive adhesive layer is formed by pattern coating. 3. The bioelectrode pad according to claim 1, wherein the entire surface of the hydrous gel layer exposed on both surfaces of the base material is coated with a separator. 4. The bioelectrode pad according to claim 1, wherein a notch is formed in the separator that covers the hydrous gel layer exposed on the lower surface of the base material.