JPH06189919A - Electrode for living body - Google Patents

Abstract

PURPOSE:To provide an electrode for a living body, which is low-priced and hardly generates polarized voltage and enables stable diagnosis or medical treatment for a long time by forming a metal thin film on a high polymer base material and stacking a conductive self-adhesive layer thereon. CONSTITUTION:A metal thin film layer formed on a high polymer base material 2 is composed of a single metal or an alloy selected from the group of Ag, Au, Cu, Pd, Ni, Cr, Pt and Al. The film thickness thereof is 5-500 angstrom, preferably 50-300 angstrom. Preferably, at least one side of the metal thin film layer 3 is covered with a thin film 4 of 10-50 angstrom Ti, C, Ni or the like. The formation of the metal thin film layer 3 is performed by evaporation, sputtering, ion plating or spray method As the conductive adhesive layer 5, an acrylic conductive hydrogel, and an ion conducting gel which is a complex of segmented polyether urethane self-adhesive agent and LiClO4, for example, are known, and both can be used.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a biomedical electrode.
The electrical or other biological phenomenon occurring inside the living body is extracted to the outside as an electrical phenomenon and used for diagnosis, for example, as an electrocardiogram, an electroencephalogram, an electromyogram, or the like. The present invention relates to an electrode used at that time, or an electrode used for treatment of a low frequency treatment device or the like.

Particularly, in recent years, disposable electrodes have been attracting attention from the viewpoints of reducing the mental burden on patients, preventing cross-infection, and hygienic. The present invention provides an electrode for a living body that is optimal for such requirements. .

[0003]

2. Description of the Related Art As a conventional disposable electrode, for example, a round or prismatic biomedical electrode obtained by attaching a conductive adhesive to a metal body obtained by sintering Ag / AgCl for an electrocardiogram and a polymer base material such as a polyester film. There is known a prismatic biomedical electrode in which carbon is printed on the surface of which a Ag / AgCl paste is printed and a conductive adhesive is attached. However, these electrodes have the drawback of high performance but high price.

[0004]

DISCLOSURE OF THE INVENTION The inventors of the present invention have arrived at the present invention as a result of earnest research on an electrode for a living body which is inexpensive, hardly causes a polarization voltage, and can be stably diagnosed or treated for a long time.

[0005]

That is, the present invention is a biomedical electrode in which a metal thin film formed on a polymer substrate and a conductive adhesive layer further laminated thereon.

In particular, the metal thin film layer is Ag, Au, Cu, P
d, Ni, Cr, Pt, or Al selected from the group consisting of alloys, and particularly preferably, the metal thin film layer has a thickness of 5
The biomedical electrode is ~ 500 Å.

Next, the present invention will be described in detail.

The polymer base material used in the present invention includes:
Although not particularly limited, a film-shaped material such as polyester resin, polycarbonate resin, nylon resin, polystyrene resin, polypropylene resin, polysulfone resin, polyarylate resin, or polyimide resin is usually used. A film thickness of 5 to 500 μm, preferably 10 to 200 μm is preferably used from the viewpoints of laminating a metal thin film layer, processing of a conductive adhesive layer, handling during diagnosis / treatment, and conformability to a living body.

In the present invention, the metal thin film layer formed on the polymer base material is Ag, Au, Cu, Pd, Ni,
It is a single alloy or an alloy selected from the group consisting of Cr, Pt, and Al. Their film thickness is 5 to 500 angstroms, preferably 50 to 300 angstroms. If it is less than 5 angstroms, the conductivity becomes small and it becomes insufficient to take out the electricity generated from the living body. If it exceeds 500 angstroms, the conductivity becomes large, but the cost is increased, which is not preferable. The above range is preferably selected from the relationship between conductivity and cost.

In the present invention, the types of the above-mentioned metal thin film layers are Ag and A in terms of both conductivity and cost.
u, Cu and Pt are preferably used. The metal thin film layer is used by being attached to a living body, but from the viewpoint of long-term stability, long-term storage stability, and durability during handling, it is 5 to 100 angstroms, preferably 10 to
A metal thin film layer coated on at least one side with 50 Å of Ti, C, Ni or the like is preferably used.
Further, instead of Ti, C and Ni, for example, In ₂ O ₃ , SnO ₄ , ITO having a film thickness of 50 to 500 Å,
It is also possible to coat at least one surface of the metal thin film layer with an oxide such as TiO ₂ or ZnO ₂ . In particular, conductive oxides such as In ₂ O ₃ , SnO ₄ , and ITO are preferable.

The metal thin film layer may be formed by any conventionally known method. Usually evaporation, sputtering,
It is performed by a method such as ion plating or a spray method.

On the metal thin film layer thus obtained, a conventionally known conductive adhesive layer is laminated by a conventionally known method.

Any conductive adhesive layer may be used as long as it has conductivity and is not harmful to the living body. Usually, acrylic conductive hydrogel, such as segmented polyether urethane adhesive, from the viewpoints of adhesive strength to living body, change in adhesive strength due to repeated application / peeling, storage stability, continuous electrical conductivity, and safety to skin. And LiClO
Ion conductive gels, which are composites of ₄ , are known and any of them can be used. Further, NaCl may be added to the above-mentioned or Poval type gel in order to impart conductivity.

[0014]

EXAMPLES Examples will be shown below, but the present invention is not limited thereto.

[0015]

Example 1 A thin film of silver / copper alloy (weight ratio: silver / copper = 90/10) was sputtered on a polyester film (125 μm) under a vacuum degree of 2.0 × 10 ⁻³ Torr. Then, a thin film of metallic titanium is added to 1.5 × 10 ⁻³
It was sputtered under Torr and laminated on the silver / copper thin film layer. The silver / copper thin film layer had a thickness of 160 Å, and the titanium layer had a thickness of 50 Å.
The surface resistance was 8Ω / □.

An acrylic conductive hydrogel having a thickness of 1 mm was laminated on the conductive film prepared as described above.

The electrode thus obtained has a size of 22 mm width × 5
It was cut to a length of 0 mm to prepare an electrode for electrocardiographic measurement as shown in FIG. The conductive gel has a size of 20 mm width × 30.
mm length.

The above electrodes were attached to the induction part of the human body shown in FIG. 2 using an electrocardiograph (ECG-6601 manufactured by Nihon Kohden Supply Co., Ltd.) and measured. The results are shown in Fig. 3.

Just like the conventional method of Comparative Example 1 described later,
Highly stable measurement results were obtained.

[0020]

Comparative Example 1 The same electrocardiograph as in Example 1 was used, and measurement was performed in exactly the same manner as in Example 1 using a conventional clip electrode (fast clip 2144-005553 manufactured by Nihon Kohden Supply Co., Ltd.) using nickel-white electrodes. The results are shown in Fig. 4.

[0021]

[Comparative Example 2] FIG. 5 shows the result of measurement in exactly the same manner as in Example 1 using a commercially available Fukuda Denshi disposable electrode (Fintax TE-119). In addition, the electrode is a silver layer 1
It had a thick film thickness of μm. Also, as seen in the measurement results, a drift was found in the baseline.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an electrocardiographic electrode showing an example of the present invention.

FIG. 2 represents a dielectric site with electrodes attached.

FIG. 3 shows results measured by an electrocardiograph using the electrodes of Example 1.

FIG. 4 shows the results obtained in Comparative Example 1.

FIG. 5 shows the results obtained in Comparative Example 2.

[Explanation of symbols]

 1 Overall view of electrode (cross section) 2 Polyester film 3 Silver / copper alloy thin film 4 Titanium thin film 5 Conductive adhesive layer

Claims (3)

[Claims] 1. A metal thin film layer formed on a polymer substrate,
A biomedical electrode further comprising a conductive adhesive layer formed thereon. 2. A metal thin film layer formed on a polymer base material is Ag, Au, Cu, Pd, Ni, Cr, Pt, Al.
The biomedical electrode according to claim 1, which is selected from the group consisting of: 3. The biomedical electrode according to claim 2, wherein the metal thin film layer formed on the polymer substrate has a thickness of 5 angstroms or more and 500 angstroms or less.