JP6573920B2 - Insulator electrode and device for low frequency electrical stimulation - Google Patents

Description

The present invention relates to an insulator electrode and device for low-frequency electrical stimulation that applies low-frequency electrical stimulation to a human body.

Low frequency electrical stimulation devices that are widely used in the world include low frequency electrical therapy devices, low frequency electrical therapy devices using interference waves, and muscle strengthening devices (EMS: Electronic Muscle Stimulation) using electrical stimulation to muscles. . These devices have at least a pair of conductive electrodes for energizing the human body (see Patent Documents 1 and 2). In addition, an electrode plate made of stainless steel is used in an electric bath that gives electric stimulation to a bather (see Patent Document 3).

On the other hand, Patent Document 4 discloses an example in which an insulator electrode having a high relative dielectric constant is brought into contact with the human head. By applying a high frequency alternating current of 50 kHz to 500 kHz between the insulator electrodes, the impedance of the insulator electrodes is lowered, an effective electric field is applied to the tumor cells existing between the electrodes, and the tumor cells are destroyed. However, there is no description of a technique for applying low-frequency electrical stimulation to the human body.

Japanese Patent No. 4605679 Patent No. 5860323 Patent No. 4057409 USP 8170684

When applying low-frequency electrical stimulation to the human body, a conductive electrode is brought into contact with the human skin, and a voltage is applied between the electrodes to pass a current. The stratum corneum is an insulator film having a capacitance, but the pores and sweat glands serve as resistance paths through which current flows. In particular, when the skin is wet with sweating or the like, an electric current easily flows. The current passing through the resistance path causes transfer of electrons on the surface of the conductive electrode, and causes an electrochemical reaction such as electrolysis of water. Thereby, when used for a long time, there is a concern about an adverse effect on the skin due to a pH change of moisture on the skin surface. In addition, since the sweat glands and pores of the skin have a relatively low resistance value, when the conductive electrode surface is brought into direct contact with the skin, the current concentrates and there is a risk of causing strong irritation and burns. In addition, when a direct current is erroneously output due to a failure of the power supply circuit, there is a concern that the direct current voltage is directly applied to the human body.

Stainless steel electrodes are used in electric baths, but the electrodes are insulated with openings because there is a risk of electrolysis of water when the electrodes are brought close together and strong irritation when directly touching the skin. It is spaced apart and fixed to the bathtub wall together with the body cover. For this reason, the electrode is freely brought into contact with the body part desired by the user and cannot receive electrical stimulation.

The present invention has been made to solve these problems, and an electrochemical reaction does not occur even when the electrode surface is wet, and even if the electrode surface is in direct contact with the skin, it can be applied to the low resistance portion of the skin. The purpose is to provide an electrode that does not cause current concentration, can be used in contact with the skin safely even in water, and can block DC outflow even if DC is accidentally output between the electrodes for some reason. It is said.

In the invention according to claim 1 of the present invention, a conductive electrode part, an insulator electrode film covering the surface of the conductive electrode part, an energization line electrically connected to the conductive electrode part, and the conductive For low-frequency electrical stimulation, comprising: an insulating covering that covers at least the conductive electrode portion and the energization line and that covers a part or all of the insulating electrode film in the previous period. An insulator electrode was obtained. In the invention according to claim 2, the electrostatic capacity per unit area of the low-frequency electrical stimulation insulator electrode film is set to 0.063 [nF / cm ² ] or more.

In the invention according to claim 3, the low-frequency electrical stimulation according to claim 1 or 2, further comprising a capacitor connected in series with the insulator electrode film in the path of the energization line. An insulator electrode was obtained. According to a fourth aspect of the present invention, there is provided a composite per unit area obtained by dividing a composite electrostatic capacitance of the insulator electrode film and a capacitor connected in series with the insulator electrode film by an electrode area of the insulator electrode film. 4. The low-frequency electrical stimulation insulator electrode according to claim 3, wherein the capacitance is 0.063 [nF / cm ² ] or more.

The invention according to claim 5 includes one or more push switches that enable connection and release of the energization line, and the low-frequency electricity according to any one of claims 1 to 4 A stimulation electrode was obtained. According to a sixth aspect of the present invention, there is provided the insulator electrode for low-frequency electrical stimulation according to the fifth aspect, wherein two or more push switches are provided and all the push switches are connected in parallel. The low frequency electrical stimulation according to any one of claims 1 to 6, wherein a surface of the insulator electrode film faces the bottom of the water and floats on water. An insulator electrode was obtained. Furthermore, in Claim 8, it provided with the draining elastic body which has a divergent opening so that the circumference | surroundings of the said insulator electrode film might be enclosed, The low of Claim 1 thru | or 7 characterized by the above-mentioned. Insulator electrodes for high frequency electrical stimulation.

The invention according to claim 9 includes at least two low-frequency electrical stimulation insulator electrodes according to any one of claims 1 to 8, and at least a peak value between the low-frequency electrical stimulation insulator electrodes. A low-frequency electrical stimulation device characterized by having a control device capable of outputting a square wave pulse voltage of 4 [V] or more. The invention according to claim 10 is the low-frequency electrical stimulation device according to claim 9, wherein a second capacitor is connected in series with the circuit at the output end of the control device. Further, in the invention according to claim 11, the output terminal of the circuit of the control device has a value twice as large as the combined capacitance in series of the second capacitor and the pair of insulator electrode films connected in series with the circuit. The low-frequency electrical stimulation device according to claim 10, wherein a capacitance per unit area obtained by dividing the above by an electrode area of the insulator electrode film is larger than 0.063 [nF / cm ² ]. did.

The invention according to claim 12 is the low-frequency electrical stimulation electrode according to any one of claims 1 to 8, wherein the electrostatic capacity per unit area is 4.1 [nF / cm ² ] or more. An even number of the low-frequency electrical stimulation insulator electrodes are provided, and the control device can output an alternating current having a frequency of 2 [kHz] or higher. Further, in the thirteenth aspect, the low-frequency electric stimulation device according to any one of the ninth to twelfth aspects is characterized in that the electric stimulation device has a waterproof structure.

The effect of the invention obtained by the above means will be described. According to the invention of claim 1, even when the electrode surface is wet or even in water, no electrochemical reaction such as pH change, gas generation or metal elution occurs on the electrode surface. A safe and comfortable electrode can be realized that does not cause pain or burns due to current concentration even if it directly contacts the electrode, and can prevent direct current outflow even if direct current outflow occurs due to an accident.

According to the inventions according to claims 2 to 4, the peak current value and the effective value current that can be passed through the human body can be used to the maximum within the range of the stimulation intensity that the human body can tolerate. Further, the invention according to claim 3 can suppress the increase in the voltage applied to the human body even when the dielectric breakdown of the insulator electrode film occurs for some reason.

According to the inventions according to claims 5 and 6, even when the insulator electrode for low-frequency electrical stimulation is used in water, energization is stopped when the user stops using the electrode, and the electrode remains energized. Since the situation of being left in water can be prevented, accidents in which an unintended electrical stimulus is suddenly received by inadvertently touching the electrode can be prevented.

With the invention according to claim 7, the convenience in use in the one-handed holding system in water is improved. When using the one-handed system, the electrode that is not held in the hand may be located anywhere in the water, but if it is sinking to the bottom of the water, it is difficult to know where it is, and there is a risk of stepping on it. When floating on the surface of the water, it is easy to use without such problems. According to the eighth aspect of the present invention, even when the electrode is lifted on the water surface while the push switch is being pressed, the formation of the water dripping passage communicating with the arm that holds the electrode does not occur, and unintentional electrical stimulation is generated on the arm. Can be prevented.

According to the ninth aspect of the present invention, a low-frequency electrical stimulation device that can output a square wave pulse voltage having a peak value of 4 [V] or more between the insulator electrodes for low-frequency electrical stimulation can be sensed with the minimum applied voltage. A lower limit stimulus can be given. In the invention according to claim 10, a capacitor is connected in series with the circuit at the output terminal of the control device of the low frequency electrical stimulation device, which makes it necessary to incorporate a series capacitor inside the insulator electrode for low frequency electrical stimulation. The insulator electrode for low frequency electrical stimulation can be made compact. In addition, multiple capacitors can be arranged and selected in the device, and variable capacitors can be arranged, increasing design flexibility and selecting a wider output voltage and RMS current. become able to. According to the invention of claim 11, the peak current value and the effective value current that can be passed through the human body can be used to the maximum within the range of the stimulation intensity that the human body can tolerate.

According to the twelfth aspect of the invention, the insulator electrode for low frequency electrical stimulation can be used even in an interference wave type low frequency electrical stimulation device using an alternating current carrier wave. Furthermore, in the invention which concerns on Claim 13, since the low frequency electrical stimulation apparatus of the said Claim 9 thru | or 12 is made into the waterproof structure, it can be used safely also in the use in water or bathing.

The basic composition of the insulator electrode for low frequency electrical stimulation of the present invention is shown. The basic composition of the low frequency electrical stimulation device of the present invention is shown. An example of the usage form during bathing of the insulator electrode for low frequency electrical stimulation is shown. An equivalent circuit when the insulator electrode for low frequency electrical stimulation is brought into contact with the skin and a current waveform when a square wave pulse voltage is applied are shown. The equivalent circuit when the insulator electrode for low frequency electrical stimulation which has a series capacitor | condenser is contact | abutted on skin, and the electric potential profile at the time of applying a square wave pulse voltage are shown. The relationship between the allowable upper limit voltage and the sensing lower limit voltage and the capacitance per unit area of the electrode during bathing when the electrode area is 3.6 [cm ² ] is shown. The usage form (both-hand holding system) during bathing of the insulator electrode for low frequency electrical stimulation is shown. The usage form (one hand holding method) during bathing of the insulator electrode for low frequency electrical stimulation is shown. The usage mode (support fixing method) during bathing of the insulator electrode for low frequency electrical stimulation is shown. The usage pattern (wall surface fixing method) during bathing of the insulator electrode for low frequency electrical stimulation is shown. The structural example of the insulator electrode for low frequency electrical stimulation which has a push switch of this invention, a draining elastic body, and a buoyancy body is shown. The insulator electrode for low frequency electrical stimulation which concerns on Example 1 is shown. The insulator electrode for low frequency electrical stimulation which concerns on Example 2 is shown. The measurement result of the relationship between the sensing lower limit voltage when changing an electrode area and the electrostatic capacitance per unit area is shown. The relationship between the sensing lower limit voltage and the electrode area when the capacitance per unit area is 1 [nF / cm ² ] is shown. The insulator electrode for low frequency electrical stimulation which concerns on Example 3 is shown. The measurement result of the relationship between the allowable upper limit voltage and the sensing lower limit voltage and the capacitance per unit area at an electrode area of 50 [cm ² ] is shown. An enlarged vertical axis near the origin of the measurement results. The horizontal axis near the origin of the measurement result is enlarged. The circuit main part of the control apparatus which incorporated the series capacitor | condenser in the output terminal is shown.

[Basic electrode configuration]
Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 shows a basic configuration of an insulator electrode 1 for low-frequency electrical stimulation according to the present invention. Reference numeral 2 denotes an insulator film that functions as an electrode surface in the low-frequency electrical stimulation insulator electrode 1 and is hereinafter referred to as an insulator electrode film. A conductive electrode portion 3 is formed on the back surface of the insulator electrode film 2. The conductive electrode portion 3 may be formed of a plurality of layers. The core wire 4001 of the energization line 4 is electrically connected to the conductive electrode portion 3 at an electrical connection point 4002. A conductive portion which is a charged portion of the low-frequency electrical stimulation insulator electrode 1 is covered with an insulating covering 5. The insulating covering may cover the end of the insulating electrode film and a part of the surface.

The insulator electrode film 2 is made of an insulator having a relative dielectric constant of about 3 to tens of thousands. For example, high dielectric constant ceramics typified by barium titanate have a dielectric constant as high as several thousand to several tens of thousands, but withstand voltage per unit film thickness is as low as several [V / μm]. It can be used by securing a withstand voltage and mechanical strength by increasing the thickness. On the other hand, in the case of resin thin films such as polyvinylidene fluoride (PVDF) and polyphenylene sulfide (PPS), the relative dielectric constant is as low as 3 to 10, but the withstand voltage per unit film thickness is several tens [V] to several hundreds [ V / μm] can be used with a thin film thickness. Inorganic thin films such as TiO2, HfO2, Ta2O5 and diamond-like carbon are also candidates.

[Basic configuration of low frequency electrical stimulation device]
2a and 2b show the basic configuration of the low-frequency electrical stimulation device. The low frequency electrical stimulation device 50 includes a power switch 51, a display unit 52, an instruction operation unit 53, and the like, and a control device 54 that can output a square wave pulse or alternating current, and at least a pair of insulator electrodes for low frequency electrical stimulation. It consists of 1 etc. In the instruction operation unit 53, the user can select the type and intensity of electrical stimulation. This instruction is transmitted to the control unit, and a voltage, a frequency, a waveform, and the like corresponding to the instruction are generated by the boosting unit and the waveform generating unit, and applied to the pair of low frequency electrical stimulation insulator electrodes 1. The output voltage of the control device 54 is 200 [V] or less for home use and 500 [V] or less for medical use. The fundamental frequency is generally 1200 [Hz] or less. In the case of using an interference wave, an alternating current of about 2 [kHz] to 10 [kHz] is used for the carrier wave. When a pulse voltage is output, the pulse width is generally several tens [μ seconds] to several hundreds [μ seconds]. The low frequency electrical stimulator is preferably waterproof. A waterproof connector or a waterproof gland is used for the take-in portion of the energization line 4, and the control device has a waterproof structure using existing technologies such as a waterproof portable electronic device, a bath controller, or a camera waterproof case. can do.

[Usage example of insulator electrode for low frequency electrical stimulation]
FIG. 3 shows a state where the insulator electrode 1 for low-frequency electrical stimulation according to the present invention is used during bathing. An insulator electrode pair for low-frequency electrical stimulation is attached to a belt-like support 6, and the belt-like support is wrapped around the waist so that the insulator electrode film is in contact with the waist. Although low-frequency electrical stimulation is applied to the affected area at the same time as thermal stimulation, the effect and comfort are enhanced, but the JIS standard for household low-frequency treatment devices prohibits simultaneous application of electrical stimulation and heating. For this reason, devices such as electrical stimulation and thermal stimulation are devised alternately in products in the world. If the insulator electrode for low frequency electrical stimulation of the present invention is used during bathing, a thermal effect by bathing and a massage effect by electrical stimulation can be obtained at the same time, and a synergistic effect is obtained.

The insulator electrode for low frequency electrical stimulation of the present invention can be used indoors. In a room, like a normal conductive electrode, it can be used by attaching hydrogel to the electrode surface, or by contacting the skin with a water-absorbing cloth or sponge containing water.

[Explanation of equivalent circuit]
An equivalent circuit when the insulator electrode for low frequency electrical stimulation is brought into contact with the human body is shown in FIG. 4a. Cins [F] indicates the capacitance of the insulator electrode film, Cskin [F] indicates the capacitance of the skin, Rskin [Ω] indicates the resistance of the skin, and Rbody [Ω] indicates the resistance inside the human body. When a square wave b of E [V] is applied to this circuit, a current I [A] as shown in FIG. 4c flows. The current rises at the same time as the voltage is applied, and decays exponentially after a peak current (Ip = E / Rbody) flows. The time for the current to decay to 1 / e of Ip (e is about 2.7 at the base of natural logarithm) is called the time constant τ, but τ is approximately given by C (composite) × Rbody [seconds] . Here, C (synthesis) is a capacitance obtained by synthesizing all of Cins and Cskin in series. The current waveform in FIG. 4c shows a case where Cins is relatively large.

When C (synthesis) is decreased, the time constant τ is decreased, and the waveform becomes thin and sharp. When the applied voltage E is further increased, Ip increases while the time constant τ remains unchanged. Even if Cins is made much larger than Cskin, the value of C (synthesis) will only asymptotically approach Cskin and will not exceed the value of Cskin.

[Description of effects]
In Example 1 to be described later, an insulator electrode for low-frequency electrical stimulation having an electrode area of 3.6 [cm ² ] is made using a sintered film of barium titanate. Using this electrode, the electrode pair was brought into contact with the surface of the human body during bathing, and a low frequency pulse voltage was applied. As a result, it has been found that comfortable electrical stimulation can be obtained even when the insulator film is used as an electrode. The square wave peak voltage when the human body begins to feel electrical stimulation, that is, the voltage half of the output voltage, is defined as the lower limit of detection voltage per electrode on one side, and the square wave when the stimulation is strong and begins to feel a burden These voltages were measured by defining half of the peak value voltage, that is, the output voltage, as the allowable upper limit voltage per electrode on one side. The result is shown in FIG.

The horizontal axis represents the capacitance Cn [nF / cm ² ] per unit area of the electrode on one side, and the vertical axis represents the voltage [V] which is half of the output voltage. That is, a voltage twice this voltage is applied between the electrodes. Both the detection lower limit voltage and the allowable upper limit voltage rise rapidly when Cn decreases. Conversely, as Cn increases, the voltage drop saturates and levels off. In the case of the allowable upper limit voltage, when Cn becomes 3.6 [nF / cm ² ] or less, the voltage rapidly increases. Therefore, this is the practical minimum value in the electrode area 3.6 [cm ² ]. Conceivable. Similarly, in the detection lower limit voltage, 0.46 [nF / cm ² ] is considered to be the minimum value. On the other hand, the minimum value of the allowable upper limit voltage is about 30 [V], and the minimum value of the sensing lower limit voltage is about 7 [V].

In this measurement, the value of Cn was changed, but this did not change the relative dielectric constant or film thickness of barium titanate. In fact, it was synthesized by connecting a capacitor in series with the barium titanate electrode. It just changes the capacitance. That is, the capacitance per unit area of the one-side electrode on the horizontal axis in FIG. 6 means a value obtained by dividing the series composite value of the capacitance of the insulator electrode film and the capacitance of the capacitor by the electrode area. Yes. Even if such an operation is performed, the current waveform and the feeling of stimulation are exactly the same as when the low frequency electrical stimulation insulator electrode having the same value as the synthetic capacitance is used alone, and the electrode surface is insulated. As long as it is a body, the effect as an insulator electrode for low-frequency electrical stimulation does not change, such as not causing an electrochemical reaction on the electrode surface.

In this way, by synthesizing a low-capacitance capacitor in series with a low-frequency electrical stimulation insulator electrode having a large capacitance, the combined capacitance is reduced and the allowable upper limit voltage is increased. As a result, the peak current value, the effective value current, and the charging energy to the capacity component of the entire system by one pulse can be increased, and the acting force on the human body can be increased. Nevertheless, since the voltage applied to the low-frequency electrical stimulation insulator electrode is kept low, the withstand voltage of the low-frequency electrical stimulation insulator electrode is not threatened even if the allowable upper limit voltage increases. This also means that an increase in the voltage applied to the human body can be suppressed to a small level even if the insulator electrode film causes dielectric breakdown for some reason under a high allowable upper limit voltage.

This will be specifically described with reference to FIG. FIG. 5d shows an equivalent circuit when a capacitor C (straight) having a small capacitance is connected in series to an insulator electrode for low-frequency electrical stimulation having a large capacitance. FIG. 5e shows a potential profile in each component when the square wave pulse voltage E [V] shown in FIG. 4b is applied to the left end of the circuit. The line indicated by t = 0 is a profile at the moment when the square wave pulse voltage is applied, there is no voltage drop due to the capacitive component, and the voltage E is all applied to the human body resistance Rbody. At this time, the peak current Ip shown in FIG. 4C flows, but immediately decreases exponentially.

The line after t = full charge shows the potential profile after charging the capacitive component and further discharging Cskin. Since the capacitance of the capacitor C (straight) is small, the voltage after full charge drops almost at the capacitor C (straight), and the voltage drop at the insulator electrode for low frequency electrical stimulation is small. Also, since Cskin is after discharge, the voltage applied to the human body is zero.

  Now, in FIG. 5e, if the left-side low-frequency electrical stimulation insulator electrode Cins breaks down and becomes conductive, the voltage burdened by this Cins is applied to the human body (in Vbody). Show). However, since Vbody is a small value with respect to the output voltage E, the voltage applied to the human body can be kept low.

In this way, by connecting a capacitor having a capacitance smaller than that of the skin or the insulating electrode film in series, the peak current value, the effective value current, and the charging energy per pulse at the same stimulation intensity As well as increasing the voltage, even if the insulator electrode film breaks down, the increase in the voltage applied to the human body can be suppressed and the safety can be improved.

[Insulator electrode film material]
Examples of inorganic materials that can be used for the insulator electrode film include titanate materials such as CaTiO3, BaTiO3, SrTiO3, Bi2TiO5, Bi4Ti3O12, La2TiO5, CeTiO4, PbTiO3, ZrTiO3, etc., and stannate materials such as BaSnO3, SrSnO3 PbSnO3, etc., zirconate-based materials, BaZrO3, CaZrO3, Bi4Zr3O12, etc., niobate-based materials, MgNbO3, CaNbO3, SrNbO3, BaNbO3, PbNbO3, etc., tantalate-based materials, LiTaO3, TaTaO3Sr, MgTaO3, SrBi2Ta2O9, etc., Bi3TiNbO9, PbBi2Nb2O9, Bi4Ti3O12, Bi2SrTa2O9, Bi2SrNb2O9, Sr2Bi4Ti5O18, Ba2Bi4Ti5O18, etc.

Resin films and thin films are also candidates. A water-resistant resin that can be formed into a film like a film capacitor, a resin that can be thinned by coating, solvent casting, electric field spraying, electrodeposition, or the like, A resin that can be thinned to a micron order by a vacuum film forming process such as sputtering. Specifically, polyphenylene sulfide (PPS), polyethylene naphthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polyethylene naphthalate (PEN), polybutylene terephthalate (PBN), unsaturated Polyester (UP), Alkyd, Polyimide (PI), Polycarbonate (PC), Polyetherimide (PEI), Polyarylate (PAR), Polyamideimide (PAI), Epoxy (EP), Para aromatic polyamide, Methacryl (PMMA) ), Melamine (MF), expanded polypropylene (OPP), polyethylene (PE), polypropylene (PP), polyvinylidene chloride (PVDC), polyvinyl chloride (PVC), polymethylpentene (PMP), polyvinylidene fluoride (PVDF) , Polytetrafluoroethylene (PTFE), polychlorotrifluoroe Len (PCTFE), Silicone (SI), Acetylcellulose, Cellulose Propionate, Nitrocellulose, Ethylcellulose, Ionomer, Polystyrene (PS), Acrylonitrile Butadiene Styrene (ABS), Acrylonitrile Styrene (AS), Polyether Ether Ketone (PEEK), Polysulfone (PSU), phenol (PF), polyurethane (PUR), diallyl phthalate, furan, and the like can be selected.

In particular, materials that can be suitably used include polyvinylidene fluoride (PVDF) and PVDF-based copolymers such as P (VDF-TrFE) and P (VDF-VF) copolymers, and P (VDF-TrFE). ) -CFE), P (VDF-TrFE-CTFE) and other terpolymers. Other examples include polyvinylidene chloride (PVDC), polyphenylene sulfide (PPS), polyvinyl chloride (PVC), polyethylene terephthalate (PET), polyimide (PI) phenol, melamine, furan, and cellulose. However, since a thin film of about 1 [μm] is weak against mechanical external force, a thickness of 4 [μm] or more is desirable, and a thickness of 10 [μm] or more is more preferable. Other examples include TiO2, La2O3, HfO2, ZrO2, Ta2O5, HfSiO4, Y2O3, Nb2O3, ZrSiO4, mica, Si3N4, SiC, and diamond-like carbon.

[Conductive bonding layer]
The configuration of the conductive electrode portion 3 formed on the back surface of the insulator electrode film 2 differs depending on the material of the insulator electrode film and the manufacturing method. For example, when a compound containing barium titanate as a main component is used as the insulator electrode film, the insulating property can be enhanced by sintering in the air instead of in a reducing atmosphere. However, if the metal electrode part is simultaneously sintered in the atmosphere, the metal electrode part is oxidized, so that it is necessary to separately sinter the ceramic sintered film. For this reason, after sintering, a conductive bonding layer is formed on the back surface. In this case, a metal thin film of platinum, aluminum, nickel, titanium or the like can be formed by a vacuum film forming process such as sputtering or vapor deposition. Alternatively, a metal thin film may be formed by applying a paste in which conductive fine particles such as silver are dispersed and then baking at a high temperature to decompose and remove organic components.

Since a ceramic sintered film is easily broken, a strong support is required on the back surface. For example, when a metal plate such as copper is used as the support, the metal thin film formed on the back surface of barium titanate and the copper plate are bonded with a conductive adhesive. In this way, a conductive electrode part can be formed.

When using a resin film such as PVDF or PVDC as an insulator electrode film, a conductive bonding film is formed on the back surface of the resin film by sputtering or vapor deposition process, or an organic conductive ink such as PEDOT / PSS is used. Can be applied to form a conductive bonding layer. However, since the organic conductive ink has a high sheet resistance value, the conductive electrode portion can be formed by further laminating a conductive foil, a sheet or a substrate, or by applying a flexible conductive adhesive or the like. Can be formed. When an insulator film is directly formed on a conductive substrate by a vacuum process, coating, or the like, the conductive substrate itself functions as a conductive bonding portion and becomes a conductive electrode portion.

[Insulating coating]
The insulating cover covers the charged part such as the conductive electrode part through which electricity passes in the insulator electrode for low frequency electrical stimulation and the core line of the energizing line, and ensures insulation from moisture around the electrode, Has the role of mechanically protecting the electrodes. As shown in FIG. 1, it may be integrally molded using a resin or an elastomer, or may be configured using a plurality of resin parts, and an interface between resin parts or an insulator electrode surface for low-frequency electrical stimulation. The interface may be sealed with an adhesive or a sealant, or may be pressure-bonded by a screw or a press-fit locking mechanism with a packing or an O-ring interposed.

[About the energizing line]
For the energization line, an insulation coated electric wire or a vinyl cabtyre cable can be used. When using an insulation-coated electric wire in water, for example, a silicone tube or a soft fluororesin tube may be joined to the insulation coating as a waterproof protective pipe, and the insulation-coated electric wire may be inserted therethrough. The length of the energization line is about 2 m. However, when the insulation-coated electric wire is inserted into the silicone tube, it is difficult to insert the conductive line because the sliding resistance of the surface is large. When a fluorine-coated electric wire and / or a soft fluororesin tube is used, since the sliding resistance is small and it is easy to insert, it is not necessary to increase the inner diameter of the tube more than necessary.

[Usage of insulator electrode for low frequency electrical stimulation]
The insulator electrode for low-frequency electrical stimulation can be used indoors or in water or bathing. When used indoors, as with conventional conductive electrodes, hydrogel is applied to the electrode surface, or a water-absorbing cloth or sponge containing water is used to contact the skin. Can be used. The wet low-frequency electrical stimulation insulator electrode can be used even if it directly contacts the skin, but when the electrode surface and the skin are dried, electrical stimulation is not felt at all.

On the other hand, when used in water or bathing, there are unique circumstances due to being underwater. First, typical usage patterns will be described. As shown in FIG. 7, the first usage mode is one in which both hands are held one by one, and both electrodes are in contact with or in close proximity to the site to which electrical stimulation is to be applied (two-hand holding method). ). Second, as shown in FIG. 8, one electrode is left in water or on the surface of the water, and the other is held in contact with or close to a human body part (one-hand holding method). As shown in FIG. 9, the third is a form in which the electrode pair is fixed to the support and is brought into contact with the skin (support fixing method). And the 4th is a system (wall surface fixing system) which fixes an electrode to a bathtub wall etc. and contacts skin there, as shown in FIG.

The two-handed system is convenient for applying electrical stimulation to the chest, abdomen, legs, and the like. In electrical stimulation in water, even if the electrode surface is not in contact with the skin, electrical stimulation can be felt only by bringing it close to the skin. When the stimulus is strong, the stimulus is softened by moving the electrode a little away from the skin. That is, a comfortable stimulation intensity can be easily found by moving the electrodes closer or away without changing the output voltage.

When you want to apply electrical stimulation to parts such as the arms, elbows, hands, and fingertips, you can't have an electrode with both hands, and you can only give stimulation with one hand. In the one-handed system, the electrode on the side to be left may be in water, and the electrodes may be separated by 1 [m] or more. The electrode on the side to be left may be attached to the bathtub wall, or the electrode surface may face down and float on the water surface. When using a conductive electrode indoors, it was difficult to contact the electrode with a large curvature such as a fingertip or a joint, but in the water, finding a comfortable stimulation condition by moving the hand electrode closer to the finger little by little be able to.

It is difficult to abut on the back, shoulder or back of the neck with the electrode in hand. In such a case, an electrode is attached to a belt-like support 6 as shown in FIG. 9c2 and wound around the body, or a cushion-like support 7 shown in FIG. 9c1 or a chair backrest-like support is used. You can attach and press your back against it. Alternatively, the electrode pair may be fixedly installed on the bathtub wall or the upper surface of the bathtub (FIG. 10), and the neck, shoulder or back may be pressed there.

[Push switch]
As described above, when used in water, the current flows even if the electrode is separated from the skin. Therefore, the control device cannot determine whether or not the use is finished. Even if the user leaves the electrode in water with the output intensity kept high, output continues to be output. If a third party inadvertently touches the electrode surface without knowing it, there is a risk of receiving a strong impact. In order to prevent such an accident, a mechanism for stopping the electrical stimulation output when the user does not use is necessary.

FIG. 11 shows a low-frequency electrical stimulation insulator electrode 104 having a push switch on the surface of the insulating covering. Reference numeral 9 denotes a hand-held push switch provided on the side surface of the insulating cover 504. When the user holds the electrode in his hand, the output circuit is connected by pressing the electrode with his fingertip, and when the user releases the hand, the output circuit is disconnected. Reference numeral 10 denotes a contact push switch provided on the back surface of the insulating covering. In a state where the electrode is attached to the electrode support, the human body senses a pressing force against the electrode surface and connects the output circuit. When the pressing force is released, the output circuit is disconnected. By providing such a switch, the output circuit can be disconnected when the user does not use it.

In the pair of insulators for low-frequency electrical stimulation, the switch may be provided on both electrodes, but since there is a one-handed method, it may be provided only on one electrode. Either one of the hand-held push switch 9 and the contact push switch 10 may be provided on one electrode, or both of them may be provided. Further, a plurality of hand-held push switches and contact push switches may be provided. When two or more switches are provided on one electrode, the switches are all connected in parallel, and when one of them is turned on, the output circuit is connected. When all the switches are turned off, the output circuit is turned on. Configure to disconnect.

Reference numeral 4044 in FIG. 11 denotes a terminal block provided in the insulator electrode 104 for low-frequency electrical stimulation, and the lead wire 4043 connected to the conductive electrode portion 304 and the core wire 4041 of the energization line are connected in parallel to each other. The hand-held push switch 9 and the contact push switch 10 are connected. A waterproof momentary push switch is suitable for the push switch, but the push switch is not limited thereto. When the insulator electrode for low frequency electrical stimulation is fixed to the bathtub wall, the contact push switch may be provided on the electrode surface or the bathtub wall surface.

[Condenser for series synthesis]
The insulator electrode for low frequency electrical stimulation can be used without connecting a capacitor for series synthesis, but can also be used with a capacitor connected. Reference numeral 13 in FIG. 11 denotes a capacitor for series synthesis. The terminal block 4044 is connected in series to the output circuit. The withstand voltage and the capacitance are determined according to the target synthetic capacitance, and can be appropriately selected from general-purpose film capacitors.

[Draining to prevent dripping electric shock]
When using an insulator electrode for low frequency electrical stimulation in water, it may happen that the electrode is lifted onto the water surface while holding the handheld push switch. At this time, water on the electrode surface flows down to the water surface along the arm. At the moment when a water passage is formed in communication between the electrode surface and the water surface, an electric current may flow to cause a tingling stimulus. In order to avoid this, as shown in FIG. 11, it is possible to avoid this by providing a diverging drainer 11 so that the dropping flow from the electrode surface is divided and does not communicate. The draining material is preferably an insulating elastomer molded body such as silicone rubber. The drainer needs to spread out. Even if the wall is perpendicular to the electrode surface as long as the water communication is only blocked, the electric field does not spread even if the electrode is slightly separated from the skin, and it is difficult to adjust the stimulation intensity. In the case of a divergent shape, since the electric field spreads by separating the electrode from the skin, the stimulation intensity can be easily adjusted.

[Buoyancy body]
As described above, in the one-handed system, one electrode may be used while being floated on water. Therefore, when at least one electrode is floated with the electrode surface down, the usability is improved. In order to give buoyancy, buoyancy may be given by providing a space inside the electrode, or a material having a specific gravity smaller than 1 may be used for the insulating covering. Moreover, as shown in FIG. 11, you may affix the buoyancy body 12 to the back surface of an electrode. The buoyancy body 12 is fixed so as to cover the contact push switch 10, but can receive the pressing force to push the contact push switch. Buoyant body materials are polyurethane resin, polystyrene resin, polyethylene resin, polypropylene resin, ethylene vinyl acetate copolymer, polyethylene terephthalate resin, phenol resin, silicone resin, polyvinyl chloride resin, urea resin, acrylic resin, polyimide resin, ethylene It can be selected from closed cell foams such as propylene diene rubber (EPDM). In particular, a polystyrene closed cell foam excellent in buoyancy is suitable. In order to attach the buoyancy body to the back surface of the electrode, water-resistant adhesive, magic tape, double-sided tape, and other fixing using a fixing member can be appropriately selected.

[Water holder]
As described above, the low-frequency electrical stimulation insulator electrode of the present invention can provide electrical stimulation to the skin as long as the wet contact is ensured at the interface between the electrode surface and the skin, even if it is not in water. However, when the wet contact is lost between the electrode surface and the skin, no irritation is felt at that portion. When the electrodes are brought into contact with the back of the neck or shoulder while bathing as shown in FIG. 9, these portions are usually on the water surface. While the skin is wet, electrical stimulation can be felt, but by providing a water holding body such as an open cell foam or a water absorbent cloth on the electrode surface, electrical stimulation can be received more stably. In addition, when the insulator electrode for low frequency electrical stimulation is brought into contact with water, the insulator film is used in contact with the skin directly. However, when the insulator film is separated from the skin by several millimeters, the stimulus becomes soft and comfortable. . Although it is difficult to maintain this separation distance by hand, the separation distance can be easily maintained by disposing a water holding body on the surface of the insulator film.

The material of the water holding member can be selected from open-cell foams, water-absorbing fibers, or a material in which a small amount of water-absorbing polymer is supported on water-absorbing fibers. The thickness may be about 1 mm to 10 mm. Open-cell foams include water-absorbing sponge made of polyurethane, polystyrene resin, polyethylene resin, polypropylene resin, ethylene vinyl acetate copolymer, polyethylene terephthalate resin, phenol resin, silicone resin, polyvinyl chloride resin, urea resin, acrylic resin Open-cell foams such as polyimide resin and ethylene propylene diene rubber (EPDM) can be selected. In particular, an open-cell foamed body of a polyether-based urethane resin is suitable because of its excellent elasticity and low hydrolyzability.

As the water-absorbing fiber, polyester, nylon, rayon, polypropylene, cellulose, cotton, or a fiber made of a mixture of these can be selected. . Further, water-absorbing fibers obtained by hydrolyzing and modifying acrylic fibers, water-absorbing fibers obtained by partially mixing or cross-linking sulfonic acids with carboxylic acids such as acrylic acid can be selected. A small amount of water-absorbing polymer supported on water-absorbing fibers can also be selected. As the water-absorbing polymer, starch acrylic acid polymer, polyacrylic acid sodium salt cross-linked product, polyethylene oxide cross-linked product and the like can be selected.

[Electrode support]
If the material of the cushioning support 7 as shown in FIG. 9C1 is an open-cell foam, it absorbs water and becomes heavy, making it difficult to handle. If it is a closed cell foam, it will float in water and will be difficult to sink. A net-like elastic body obtained by knitting a filter sponge or fiber in a three-dimensional shape is preferable. In particular, a three-dimensional structured random loop of continuous filaments made of a thermoplastic elastomer having rubber elasticity is suitable. It is convenient because it has good water crispness and sufficient elasticity, and it can also be abutted on the neck to put a pillow on the corner of the bathtub. In the case of the wrapping type support shown in FIG. 9C2, an electrode is attached to a belt made of a stretch material made of polyurethane elastic fiber and the like is wound around a back or a shoulder. A locking mechanism such as a magic tape or a hook can be used for attaching the electrode.

The insulator electrode 101 for low frequency electrical stimulation shown in FIG. 12 was manufactured using the sintered film of the complex oxide which has barium titanate as a main component for an insulator electrode film. High dielectric constant type barium titanate powder (Y5V-180, manufactured by Kyoritsu Material Co., Ltd.) was sintered in the air to produce an insulator electrode film 201 having a diameter of 3 [cm] and a thickness of 100 [μm]. A conductive paste (Noritake Co., Ltd., NP-4311A) was applied to the back surface of the insulator electrode film 201 and baked to form a conductive bonding layer 3011 having a thickness of about 15 [μm]. Next, the conductive electrode part 301 was comprised by adhere | attaching with the electroconductive board | substrate 3013 which consists of a copper plate of thickness 2 [mm] using Fujikura Kasei Co., Ltd. Dotite XA-874 as the electroconductive adhesive layer 3012. Lead wires 4013 were soldered to the back surface of the conductive substrate 3013 and connected to the terminal block 4014. A lead wire 4011 of an energization line 401 made of a lead wire and a fluorine-coated electric wire is connected by a terminal block 4014. The energization line 401 is housed in a soft fluorine tube 4015 as a waterproof pipe. The waterproof pipe 4015 is inserted into a waterproof gland (manufactured by Takachi Denki Kogyo Co., Ltd., IP68 resin) 4016 that is screwed and attached to the side of a housing 5011 made of hard vinyl chloride, and is waterproofly fixed. The conductive charging portion of the electrode is covered with a housing 5011, a cover ring 5012, and a waterproof sealant 5013 that form an insulating covering 501 and is housed in a waterproof structure.

The effective area of this insulator electrode film was 3.6 [cm ² ]. The capacitance in water at 40 ° C. was 417 [nF] on average when the square wave peak value was 15 [V] or less, and 405 [nF] on average between 15 [V] and 30 [V]. The relative dielectric constant of barium titanate (Y5V-180) decreases remarkably when the temperature rises above room temperature. Furthermore, the relative dielectric constant is also greatly reduced by increasing the applied DC voltage (so-called DC bias characteristics). However, in an environment of 40 ° C, the DC bias characteristic is relaxed and becomes a relatively flat characteristic.

[Measurement 1: Measurement of sensing lower limit voltage and allowable upper limit voltage in bathing]
Using this barium titanate electrode pair, low frequency electrical stimulation was given in water to a subject taking a bath at a water temperature of 40 ° C. Applying a pulse voltage while gradually increasing the peak value, the voltage half of the output voltage (sensing lower limit voltage) when you first feel an electrical stimulus, and the half of the output voltage when the stimulus intensity feels the upper limit of the allowable range Was measured by changing the capacitance Cn [nF / cm ² ] per unit area of the electrode on one side from 0.46 to 113 [nF / cm ² ] in 10 steps.

The on-time of the square wave pulse is 300 [μs], the frequency is 50 [Hz], the same polarity pulse is generated 200 times, then the 0.5 [second] pause period is inserted, and then the opposite polarity pulse is 200 times The waveform was generated and repeated thereafter. In the case of an insulator electrode for low-frequency electrical stimulation, the sensing lower limit voltage is almost constant even when the frequency is changed from 5 [Hz] to 1200 [Hz]. Therefore, the standard frequency is set to 50 [Hz]. The contact point of the insulator electrode for low frequency electrical stimulation is the part where the electrode up to 100 [cm ² ] can stably contact, and the most common contact part is the waist (lower back) Left and right across the spine. The capacitance per unit area was changed by synthesizing capacitors in series with the barium titanate electrode as described above. The measurement results are as described in FIG.

Another embodiment will be described with reference to FIG. In this example, a polyphenylene sulfide film (Torelina (registered trademark) manufactured by Toray Industries, Inc.) having a thickness of 1.2 [μm] was used as the insulator electrode film 202. On the back surface of this film, a Ni thin film is deposited as a conductive bonding layer 3021. A low-viscosity conductive adhesive was applied as a conductive adhesive layer 3022 on a stainless steel substrate as the conductive substrate 3023, and a Ni thin film surface deposited on a polyphenylene sulfide film was bonded thereon. A core wire 4021 of the energization line 402 was connected to the back surface of the stainless steel substrate 3023 using a conductive adhesive, and an electrical connection point 4022 was obtained. A vinyl cab tire cable was used for the energization line 402. A clamp 4023 is attached to the end of the energization line so that the pulling force to the energization line can be received. A through hole is provided on the side surface of the electrode housing 5021, and a rubber bushing 4024 is fitted and fixed. The energization line 402 was inserted into the rubber bushing. A low-viscosity epoxy is potted inside the electrode housing 5021, and an electrode plate composed of the insulator electrode film 202 and the conductive electrode portion 302 is placed thereon so that the end face and the end of the surface of the electrode plate are covered. A low-viscosity epoxy was filled to form a waterproof seal 5022.

The capacitance of this electrode was measured. After wetting the electrode surface with water, place a metal electrode, apply a pulse voltage between the terminals, acquire a current waveform with an oscilloscope, grasp the amount of charging current by numerically processing this, and apply a pulse wave at room temperature The capacitance at the time was measured. As a result, 2.5 [nF / cm ² ] was obtained.

[Measurement of electrode area and feeling of stimulation]
Next, using this electrode, the effective area of the electrode is 5 [cm ² ], 10 [cm ² ], 30 [cm ² ], 50 [cm ² ], 70 [cm ² ], and 100 [cm ² ]. In each case, when the capacitance Cn [nF / cm ² ] per unit area of the electrode on one side was changed, a voltage (sensing lower limit voltage) at which an electric stimulus was first felt was measured. This measurement was performed indoors, not in water. A water absorbent cloth having a thickness of about 1 [mm] was placed on the surface of the electrode, and it was in contact with the waist in a state where water was sufficiently absorbed. The effective area was changed by placing a resin sheet having an opening corresponding to each effective area on the electrode surface. Other measurement conditions are the same as those in Example 1.

The measurement results are shown in FIG. It can be seen that if the capacitance Cn per unit area of the electrode on one side is the same, the sensing lower limit voltage decreases as the electrode area increases. However, the change from 30 [cm ² ] to 100 [cm ² ] is small and the decreasing tendency is saturated. When the approximate curve is obtained by using the power curve by the least square method for each electrode area data, the R square value is 0.98 or more, and a good approximation is obtained. FIG. 15 shows the result of obtaining the sensing lower limit voltage when Cn is 1 [nF / cm ² ] using these curves. From this result, it is considered that the detection lower limit voltage does not change when the electrode area is 50 [cm ² ] or more. That is, when the electrode area is set to 50 [cm ² ], it can be seen that the measurement can be performed under the conditions that are most easily felt.

This embodiment will be described with reference to FIG. Nine barium titanate sintered films 203 with an outer dimension of 28 mm mm are prepared, juxtaposed on the same plane, and electrically connected in parallel to provide insulation for low-frequency electrical stimulation with an electrode area of 50 cm ² A body electrode 103 was constructed. A conductive electrode portion 303 was created with the same material structure as in Example 1. Lead wires 4033 were soldered to the back surfaces of these conductive electrode portions 303 to form electrical connection points 4032. Nine lead wires 4033 were connected to the terminal block 4034 and connected to the core wire 4031 of the energization line 403. As in the first embodiment, the energization line 403 is inserted into a waterproof pipe 4035 made of a soft fluorine tube, and the soft fluorine tube is fixed to the resin electrode housing 5031 by a waterproof gland 4036. Nine electrode plates were placed on the upper surface of the electrode housing and fixed with an epoxy adhesive 5033.

[Measurement of stimulation with electrode area of 50 cm ² ]
In the same manner as in Example 1, the sensing lower limit voltage and the allowable upper limit voltage when the capacitance Cn per unit area of the electrode on one side was changed were measured. The result is shown in FIG. The vertical axis is half of the output voltage [V], and the horizontal axis is the unit of one side of the low-frequency electrical stimulation insulator electrode or the series of the low-frequency electrical stimulation insulator electrode and capacitor on one side. The capacitance per area is Cn [nF / cm ² ]. ● is the allowable upper limit voltage, and ▲ is the detection lower limit voltage. The maximum value of Cn is 200 [nF / cm ² ]. This is the capacitance at room temperature of the barium titanate film. The maximum value of one-side applied voltage is applied up to 255 [V].

FIG. 18 is an enlarged view of the vertical axis near the origin of FIG. The detection lower limit voltage is constant at about 2 [V] above 44 [nF / cm ² ]. On the other hand, the allowable upper limit voltage is constant at about 9 [V] above 94 [nF / cm ² ]. That is, from the viewpoint of lowering the allowable upper limit voltage, increasing Cn beyond this is not effective. FIG. 19 is an enlarged view of the horizontal axis near the origin of FIG. Both the detection lower limit voltage and the allowable upper limit voltage rapidly increase as Cn decreases.

For the lower limit of detection voltage (U [V]), a power approximation curve was obtained by the least square method for data of 5 subjects in a range where Cn was smaller than 4 [nF / cm ² ]. As a result, the formula (2) was obtained.
U = 17.7 * Cn ^ -0.861 (2)
(R ^ 2 = 0.9551)

If Cn is decreased, the detection lower limit voltage rises rapidly, which is not desirable from the viewpoint of safety and effectiveness. The JIS standard also specifies that the maximum output voltage is 500 [V]. That is, the practical maximum voltage of U is considered to be 250 [V]. Cn = 0.063 [nF / cm ² ] is obtained by calculating Cn when U = 250V using the above equation (2). It can be said that this value is the minimum capacitance per unit area of the electrode on one side, which is necessary for applying electrical stimulation to the human body using the low-frequency pulse voltage.

On the other hand, the allowable upper limit voltage is 255 [V] when Cn is 0.36 [nF / cm ² ]. Therefore, the minimum Cn necessary to feel the stimulus up to the upper limit is considered to be about 0.36 [nF / cm ² ]. At this time, a peak value 510 [V] is applied between the electrodes, and the peak current reaches 2.3 [A], but the time constant is about 1 [μsec] and the human body is damaged. That doesn't happen.

When Cn is 200 [nF / cm ² ] and 0.36 [nF / cm ² ], the waveform data of charge / discharge current when the allowable upper limit voltage is applied is taken into the digital oscilloscope, and the effective value current is obtained by calculation. When it is 200 [nF / cm ² ], it is about 11 [mA], and when it is 0.36 [nF / cm ² ], it is about 25 [mA], increasing about 2.5 times.

From the above results, in the insulator for low frequency electrical stimulation that applies low frequency electrical stimulation to the human body, in order to give minimal sensing stimulation, 0.063 [nF / cm ² ] per unit area of the electrode on one side It can be concluded that a capacitance per unit area of one electrode of 0.36 [nF / cm ² ] or more is necessary to give an allowable upper limit stimulus. Further, the output voltage of the low-frequency electrical stimulation device requires an output voltage of 4 [V] or more to give a sensing lower limit stimulus and 18 [V] or more to give an allowable upper limit stimulus. I can conclude.

[Example of low-frequency electrical stimulation device]
The main part of a circuit in which a synthesis capacitor is connected in series with the circuit at the output terminal of the control device in the low-frequency stimulation device will be described with reference to FIG. A bipolar or unipolar square wave pulse is generated by the waveform generator and applied from the output terminal 56 to the pair of electrodes 1. A series synthesis capacitor 55 was connected in series immediately before the output terminal 56. In the figure, one capacitor is connected to each of the two output terminals, but the capacitor may be connected to either one. Further, a plurality of capacitors may be arranged in parallel so that a capacitor to be connected can be selected, or a capacitor whose capacitance can be varied may be connected. When the capacitor is connected to either one as described above, the value obtained by doubling the value of all the series combined capacitances of the capacitance of the pair of insulator electrode films and the capacitors connected in series is This is the capacitance per insulator electrode for low frequency electrical stimulation.

[AC applied]
In the present invention, it has been explained that a human body can feel electrical stimulation by applying a low-frequency square wave pulse voltage to an insulator electrode for low-frequency electrical stimulation. The merit that the current does not concentrate on the resistance portion is effective for a pulse wave other than a square wave or an alternating current. When alternating current is applied, the insulator electrode for low frequency electrical stimulation having the capacitance C [F] is simply a 1 / (2πfC) resistor. Here, f is a frequency [Hz]. In the interference wave type electrical stimulation apparatus, generally, an alternating current of 2 [kHz] to 10 [kHz] is used as a carrier wave. From this, it is possible to obtain the minimum capacitance per unit area that is required when the insulator electrode for low frequency electrical stimulation is used in the interference wave type electrical stimulation device.

For example, when the electrode area is 10 [cm ² ], the skin capacitance is 150 [nF], Rskin is 1440 [Ω], and Rbody is 300 [Ω]. Therefore, the skin impedance when an alternating current of 2 [kHz] is applied is 498 [Ω]. That is, it can be said that even when the skin impedance is 498 [Ω], the interference wave type electrical stimulation can be effectively applied to the human body. On the other hand, the skin impedance when an alternating current of 10 [kHz] is applied is 106 [Ω]. Therefore, at 10 [kHz], even if an impedance of 498−106 = 392 [Ω] is added to the outside of the skin, it can be used effectively. The capacitance when 392 [Ω] at 10 [kHz] is 41 [nF]. In other words, if the capacitance per unit area of the low-frequency electrical stimulation insulator electrode is 41 ÷ 10 = 4.1 [nF / cm ² ] or more, the low-frequency electrical stimulation insulator electrode is connected to the interference wave electrical stimulation. It can also be used in the apparatus. This result does not change even if the electrode area is changed.

  Even when the electrode is wet, or even while bathing or taking a bath, the electrode can be brought into contact with or close to a free position of the human body to apply low-frequency electrical stimulation. This makes it possible to achieve synergistic effects by performing low-frequency electrical therapy simultaneously with the thermal effect of bathing, and also to use muscle training by electrical stimulation while exercising in the pool, a new use that has never existed before The possibilities expand.

DESCRIPTION OF SYMBOLS 1 Insulator electrode 2 for low frequency electrical stimulation 2 Insulator electrode film 3 Conductive electrode part 4 Conductive line 5 Insulating coating body 6 Belt-like support body 7 Cushion support body 9 Hand-held push switch 10 Contact push switch 11 Draining Elastic body 12 Buoyant body 13 Series composition capacitor 50 Low frequency electrical stimulation device 54 Control device 55 Series composition capacitor 56 Output terminal

Claims (12)

At least a conductive electrode part, an insulator electrode film covering a surface of the conductive electrode part, an energization line electrically connected to the conductive electrode part, and the conductive electrode part and the energization line And an insulating covering for covering the insulating electrode film so as to expose a part or all of the insulating electrode film, wherein the unit area of the insulating electrode film is provided. An insulator electrode for low-frequency electrical stimulation that can be stimulated by the human body, characterized in that the per-capacitance is 0.36 [nF / cm ² ] or more.   The power supply line includes a capacitor that is connected in series with the insulator electrode film and that generates a combined capacitance with the insulator electrode film. The insulator electrode for low frequency electrical stimulation which the human body of claim | item 1 can feel irritation | stimulation. Per unit area obtained by dividing the combined capacitance of the capacitance of the insulator electrode film and the capacitance of a capacitor connected in series with the insulator electrode film by the electrode area of the insulator electrode film ^{3. The} low-frequency electrical stimulation insulator according to claim 2, wherein the human body can feel stimulation according to claim 2, wherein the synthetic capacitance is 0.36 [nF / cm ² ] or more.   The human body according to any one of claims 1 to 3, wherein the human body according to any one of claims 1 to 3 is provided with one or more momentary operation push switches that enable connection and release of the energization line. Insulator electrode for low frequency electrical stimulation.   5. The insulator electrode for low frequency electrical stimulation according to claim 4, wherein two or more push switches are provided, and all the push switches are connected in parallel. 5.   6. The low-frequency electricity that allows a human body to feel a stimulus according to claim 1, wherein the surface of the insulator electrode film faces the water surface and floats on water. Insulator electrode for stimulation.   The human body according to any one of claims 1 to 6, further comprising a draining elastic body having a divergent opening so as to surround the periphery of the insulator electrode film. Insulator electrode for low frequency electrical stimulation.   A square wave having at least two low-frequency electrical stimulation insulator electrodes according to any one of claims 1 to 7 and having a peak value of 4 [V] or more between the low-frequency electrical stimulation insulator electrodes. A low frequency electrical stimulation device comprising a control device capable of outputting a pulse voltage.   A second capacitor for generating a synthetic capacitance with the insulator electrode film is connected in series with the insulator electrode film, and is connected to the inside of the control device. The low frequency electrical stimulation device according to claim 8. In the low-frequency electrical stimulation device, a value twice the combined capacitance of the capacitance of the pair of insulator electrode films and the capacitance of the second capacitor is an electrode of the insulator electrode film. The low frequency electrical stimulation device according to claim 9, wherein the capacitance per unit area divided by the area is larger than 0.36 [nF / cm ² ]. The low-frequency electrical stimulation insulator electrode according to any one of claims 1 to 7, wherein the low-frequency electrical stimulation insulator electrode has a capacitance of 4.1 [nF / cm ² ] or more. A low frequency electrical stimulation device comprising an even number and capable of outputting an alternating current having a frequency of 2 [kHz] or higher. The low-frequency electrical stimulation device according to any one of claims 8 to 11, wherein the low-frequency electrical stimulation device has a waterproof structure.