Medical device

Abstract

Provided is a flexible medical device that is excellent in hygiene, has high safety in post-disposal treatment even when disposable, and is disposable. 【Solution means】One medical device 100 of the present invention includes an elastic layer 10 made of conductive polyurethane, and a first electrode layer 20 containing silver, silver chloride, and a resin on at least a part of one first surface of the elastic layer 10. In addition, this medical device 100 is a medical device capable of flowing a current between the surface of the first electrode layer 20 and the other second surface of the elastic layer 10.

Description

Technical Field

[0001] The present invention relates to a medical device.

Background Art

[0002] So far, as an electrode for a living body or a device including the electrode, a laminated structure having a resin or a paper molding sheet as one layer has been developed. In addition to the selection of the type or material of the layer, a plurality of devices for improving the conductivity from both sides of the resin layer have been disclosed in the prior art (Patent Documents 1 to 3).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the development and realization of a medical device for a living body including a laminated structure using a material (typically, a material as a base material) having all the characteristics shown in the following (a1) to (f1) are still in an intermediate stage.

[0005] (a1) From the viewpoint of hygiene, disposable medical devices are widely adopted. For example, it is environmentally friendly such that the safety of disposal after use (for example, incineration) is easily ensured and / or silver recycling is possible.

[0006] (b1) It has little odor for patients sensitive to odor.

[0007] (c1) It has flexibility that is hardly affected by the temperature during use. For example, when it is arranged to contact a part of a human body (e.g., the skin), or when it is pasted, it can easily follow the curved surfaces of parts such as the human head, neck, arm, chest, abdomen, thigh, and foot, or can easily follow the movement even when each part moves.

[0008] (d1) For example, it is easy to use even for patients with sensitive skin, such as children, women, or the elderly.

[0009] (e1) It has good air permeability and is easy to use even in a high-humidity environment.

[0010] (f1) It can be manufactured at a low cost.

[0011] Also, when a medical device having the above-described laminated structure is used as an electrode, there remains much room for research and development on materials or structures having all of the characteristics shown in the following (a2) to (b2).

[0012] (a2) It has low electrical resistance.

[0013] (b2) Even if it is a weak electrical signal (typically, a biological signal), it can be detected with high accuracy.

Means for Solving the Problems

[0014] The present invention can greatly contribute to the realization of a medical device for a living body that can also be used as a constituent member of an electrode by solving a plurality of the above-described technical problems.

[0015] The inventor conducted repeated research and analysis to create materials and structures that can solve the above-described technical problems. Specifically, the inventor learned that in manufacturing a medical device as a laminate structure, the material and its structure that mainly serve as a base material can greatly affect the solution of the above-described technical problems. As a result of further research and development by the inventor, it has been found that a urethane resin (polyurethane) imparted with conductivity is most suitable as a material that mainly serves as a base material.

[0016] In addition, when appropriately exerting the function as an electrode in a medical device, the inventor learned that appropriately selecting metal particles that can contribute to the detection of an electrical signal (typically, a biological signal) disposed on or above the above-described base material, and / or devising the shape of the metal particles can contribute to overcoming the above-described technical problems. The present invention was created from the above-described respective viewpoints.

[0017] One medical device of the present invention includes an elastic layer made of conductive polyurethane, and a first electrode layer containing silver, silver chloride, and a resin on at least a part of one first surface of the elastic layer. In addition, this medical device is a medical device capable of passing an electric current between the surface of the above-described first electrode layer and the other second surface of the above-described elastic layer.

[0018] According to this medical device, since an elastic layer made of conductive polyurethane is adopted as a material that mainly serves as a base material, and has a structure in which a first electrode layer containing silver, silver chloride, and a resin and the elastic layer are laminated, at least the problems (a1), (b1), and (c1) among the above-described technical problems can be solved.

[0019] In the above invention, the silver being whisker-shaped silver particles is a preferred embodiment because it can greatly contribute to solving particularly the problems (a2) and (b2) among the above technical problems. Further, as long as the conductivity in each thickness direction of the above elastic layer and the first electrode layer is obtained to a degree useful as a medical device, the thickness of each of the elastic layer and the first electrode layer is not limited. In addition, as long as the conductivity in the thickness direction is obtained to a degree useful as a medical device, the type of the above resin is also not limited.

[0020] In the present application, "layer" and "film" have the same meaning. Further, the "layer" in the present application is not limited to a continuous layer with a uniform thickness. Therefore, the "layer" in the present application includes continuous layers with different thicknesses. Furthermore, the "layer" in the present application includes, for example, those formed such that, on a certain substrate, the material to be targeted is in a discontinuous state where it is, so to speak, in a plurality of island-like forms with substantially the same thickness or different thicknesses.

Advantages of the Invention

[0021] According to one medical device of the present invention, at least the problems (a1), (b1), and (c1) described above can be solved.

Brief Description of the Drawings

[0022]

Figure 1

Figure 2

Figure 3

Figure 4

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Figure 6

Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0023] Hereinafter, embodiments of the present invention will be described in detail based on the accompanying drawings. In this description, throughout all the figures, unless otherwise particularly noted, common reference numerals are assigned to common parts. Also, in the figures, the elements of this embodiment are not necessarily shown to scale. Further, for ease of viewing each drawing, some reference numerals and shapes may be omitted.

[0024] <First Embodiment> [Configuration of the Medical Device of the Present Embodiment and Its Modification Example (1)] FIG. 1 is a cross-sectional view showing the configuration of the medical device 100 of the present embodiment. As shown in FIG. 1, the medical device 100 is a laminated structure of an elastic layer 10 made of conductive polyurethane and a first electrode layer 20 containing silver (Ag), silver chloride (AgCl), and resin. Further, FIG. 2 is a cross-sectional view showing the configuration of a medical device 100a which is one modification example (1) of the medical device 100 of the present embodiment. In the medical device 100a which is the modification example (1), since it has the same configuration as the medical device 100 except that the arrangement of the first electrode layer 20 is different from that of the first electrode layer 20 of the medical device 100 of the present embodiment, duplicate explanations may be omitted.

[0025] As shown in FIG. 1, in the medical device 100, a state is shown in which the first electrode layer 20 is uniformly arranged so as to substantially cover the entire surface (the first surface 12 in FIG. 2) of the elastic layer 10 and has substantially the same thickness.

[0026] On the other hand, as shown in FIG. 2, on the elastic layer 10 of the medical device 100a which is the modification (1), the first electrode layer 20 is formed so as to cover a part of the surface (the first surface 12) of the elastic layer 10 in one or more island-like states with substantially the same thickness.

[0027] Here, from the viewpoint of being easy to process into a shape that can follow the shape or movement of human skin or each part, it is a preferable aspect that the first electrode layer 20 is uniformly arranged so as to cover all of the surface of the elastic layer 10 and has substantially the same thickness, like the medical device 100. On the other hand, from the viewpoint that cracks or splits are less likely to occur in the first electrode layer 20 when following the shape or movement of human skin or each part, it is a preferable aspect that the first electrode layer 20 is arranged so that a part of the surface of the elastic layer 10 is not covered, like the medical device 100a which is the modification (1).

[0028] Next, the elastic layer 10 and the first electrode layer 20 constituting the medical device 100 of the present embodiment and the medical device 100a of the modification (1) thereof will be described.

[0029] Polyurethane, which is the main material of the elastic layer 10 that plays the role of a base material in the medical device 100 and the medical device 100a, has high flexibility such that when arranged to contact a part of a human (for example, the skin), or when pasted, it can follow the curved surfaces of parts such as the human head, neck, arm, chest, abdomen, thigh, and foot, or follow the movement and the curved surfaces even when each part moves.

[0030] Therefore, when the medical device 100 is used as an electrode, in order to make use of its high flexibility, it is a preferable aspect that the thicknesses of the first electrode layers 20 arranged on the elastic layer 10 are substantially the same. Also, it is another aspect that can be adopted that the first electrode layer 20 is formed so that a part or all of the surface (the first surface 12) of the elastic layer 10 is covered in a discontinuous state with different thicknesses of the first electrode layer 20.

[0031] In addition, it is a preferred embodiment from the viewpoint of highly sensitively detecting an electric signal (typically, a biological signal) to a degree useful as a medical device that the amount of carbon blacks (including conductive carbon black, Ketjen black, graphite, and mesoporous carbon), carbon nanotubes, graphene, graphene mesosponge, or acetylene black, which is a conductive material contained in the polyurethane, is adjusted so that the surface resistance value of the elastic layer 10 is 0.1 Ω or more and 100 Ω or less (more preferably, 5 Ω or more and 70 Ω or less).

[0032] In addition, it is a preferred embodiment from the viewpoint of obtaining conductivity in the thickness direction to a degree useful as a medical device and, as a result, highly sensitively detecting an electric signal (typically, a biological signal) that the amount of each of the above-described conductive materials contained in the polyurethane is adjusted so that the resistance value in the thickness direction of the elastic layer 10 is 0.1 Ω or more and 1000 Ω or less (more preferably, 1 Ω or more and 100 Ω or less).

[0033] In addition, as described above, since the main material of the elastic layer 10 of the present embodiment is polyurethane, for example, when the elastic layer 10 is arranged to contact human skin, using the elastic layer 10 made of conductive polyurethane is a preferred embodiment from the viewpoint of easily maintaining the function as a medical device because it can achieve high hygroscopicity with respect to human sweat. Further, it is a preferred embodiment from the viewpoint of realizing an elastic layer 10 having higher flexibility and followability with higher accuracy that the tensile elongation rate of the elastic layer 10 is 50% or more (more preferably, 70% or more, still more preferably 100% or more) and / or the glass transition temperature (Tg) of the elastic layer 10 is less than 70°C (more preferably, 50°C or less).

[0034] Further, from the perspective of more accurately realizing that the medical devices 100 and 100a follow along the curved surface of each part of the human body, the resin, which is one of the materials constituting the first electrode layer 20, is preferably a resin having flexibility and followability, similar to the polyurethane that bears the above-described flexibility and followability in the elastic layer 10. Examples of typical such resins (hereinafter referred to as "first resins") are acrylic resins, acrylic copolymers, epoxy resins, urethane resins, silicone resins, or polyester resins. Note that it is a preferred embodiment from the perspective of more accurately realizing the first electrode layer 20 having flexibility and followability that the resin is an acrylic resin or an acrylic copolymer having a molecular weight of 5,000 or more and 300,000 or less, and / or the glass transition temperature (Tg) is 100°C or less.

[0035] Further, the thickness of the elastic layer 10 is not limited as long as the conductivity required for the medical device or according to the purpose can be exhibited. From the perspective of obtaining a state that is easy to follow even when, for example, the elastic layer 10 is arranged to contact a part of the human body (for example, the skin) or when it is pasted, and follows the undulations, unevenness, turning parts, bending parts, or stretching parts on the surface of the human skin with high accuracy, the thickness is preferably 250 μm or less (more preferably 100 μm or less). This is because when the thickness of the elastic layer 10 exceeds 250 μm, cracks may be formed in the elastic layer 10 when following the movements of parts such as the head, neck, arm, chest, abdomen, thigh, and foot of the human body. On the other hand, from the perspective of obtaining sufficient strength as a medical device, the thickness of the elastic layer 10 that can play the role of a base material is preferably 40 μm or more.

[0036] Next, the mass ratio of the total of silver (Ag) and silver chloride (AgCl) to the resin in the first electrode layer 20 is not limited as long as the conductivity required for the medical device or according to the purpose can be exhibited. From the perspective of reducing the environmental load or achieving cost reduction, the ratio of the total mass of silver (Ag) and silver chloride (AgCl) to the mass of the resin is preferably such that the mass of the resin is 0.05 or more and 0.45 or less (more preferably 0.15 or more and 0.25 or less) when the total mass is set to 1.

[0037] Further, the mass ratio of silver (Ag) to silver chloride (AgCl) in the first electrode layer 20 is not limited as long as the conductivity required for the medical device or according to the purpose can be exhibited. Similar to the above, from the viewpoint of reducing the environmental load or realizing cost reduction, or from the viewpoint of highly accurately detecting an electrical signal (typically, a biological signal) even when the medical device is bent, the mass ratio of silver (Ag) to silver chloride (AgCl) is such that when silver (Ag) is 1, silver chloride (AgCl) is 0.05 or more and 2.5 or less (more preferably, 0.1 or more and 1.6 or less), which is a preferred embodiment.

[0038] Also, regarding the thickness of the first electrode layer 20, similar to the thickness of the elastic layer 10, it is not limited as long as the conductivity required for the medical device or according to the purpose can be exhibited. From the viewpoint of highly accurately detecting an electrical signal (typically, a biological signal), the thickness is preferably 2 μm or more (more preferably, 3 μm or more, still more preferably, 3.5 μm or more). On the other hand, from the viewpoint of obtaining a state that can easily follow even when, for example, placed in contact with a part of a human body (for example, the skin) or pasted, the thickness is preferably 30 μm or less (more preferably, 15 μm or less). This is because when the thickness of the first electrode layer 20 exceeds 30 μm, there is a possibility that cracks or splits may be formed in the first electrode layer 20 when following the movements of parts such as the head, neck, arm, chest, abdomen, thigh, and foot of a human body.

[0039] <Modification Example (2) of the First Embodiment> Incidentally, the shape of silver (Ag) in the first electrode layer 20 is not limited to a substantially spherical shape, and it is also a suitable embodiment that can be adopted that the silver is, so to speak, flaky particles. Therefore, in this modification, it can be adopted that the silver (Ag) contains the flaky silver particles. An example of the average particle diameter (D50) of the typical flaky particles that can be adopted in this modification is about 2 μm or more and about 7 μm or less (more narrowly, about 3.5 μm or more and about 5 μm or less). In this embodiment, the average particle diameter is the cumulative median diameter (Median diameter) at which the cumulative curve becomes 50% by volume when the total volume of the powder population is set to 100% and the cumulative curve is obtained. The average particle diameter can be measured using the dynamic light scattering method.

[0040] Further, the silver (Ag) is not limited to the case where it exists as the silver (Ag) alone. For example, it is also an embodiment that can be adopted that the silver is silver covering potassium titanate. Therefore, in this modification, it can be adopted that the silver (Ag) contains silver covering potassium titanate. Incidentally, the fact that the silver is flaky particles, or that the potassium titanate covered with the silver has a so-called whisker-like structure with a predetermined (typically 10 or more and 240 or less (more narrowly, 15 or more and 100 or less)) aspect ratio can greatly contribute to enhancing the conductivity of the first electrode layer 20, that is, being able to detect an electrical signal (typically a biological signal) with high sensitivity. In this embodiment, silver covering potassium titanate having the aforementioned predetermined aspect is referred to as "silver covering whisker-like potassium titanate".

[0041] Here, the fact that the first electrode layer 20 contains at least one selected from the group of the aforementioned flaky silver particles and silver covering the aforementioned whisker-like potassium titanate that can be adopted in this modification means that, compared with substantially spherical silver (Ag) particles, even if silver chloride (AgCl) is granular such as substantially spherical, the unevenness on the surface of the first electrode layer 20 is more accurate. In other words, more unevenness with a large height difference is formed. As a result, the surface area of the entire first electrode layer 20 becomes substantially larger.

[0042] Then, for example, even if the area of the elastic layer 10 that mainly serves as a base material is the same, compared with the medical devices 100 and 100a that do not contain at least one selected from the group of silver covering the flaky silver particles and the whisker-shaped potassium titanate described above, the area in contact with the human skin will substantially expand. As a result, it is particularly worthy of note that an electrical signal (typically, a biological signal) can be obtained with higher accuracy. In addition, the fact that the first electrode layer 20 described above contains silver covering whisker-shaped potassium titanate can reduce the amount of silver used in the entire first electrode layer 20, and thus can also greatly contribute to reducing the cost of the entire medical device.

[0043] In addition, typical potassium titanate that can be adopted in this modification example is substantially columnar, substantially conical, substantially polygonal frustum-shaped or substantially polygonal columnar, with a maximum diameter (maximum width) of about 0.1 μm or more and about 1 μm or less (more narrowly, about 0.2 μm or more and about 0.6 μm or less), and a length (height) of about 8 μm or more and about 24 μm or less (more narrowly, about 10 μm or more and about 20 μm or less). In addition, the film thickness of silver (Ag) covering the potassium titanate is about 0.05 μm or more and about 0.3 μm or less (more narrowly, about 0.08 μm or more and about 0.26 μm or less).

[0044] In addition, the first electrode layer 20 is not limited to containing only one of the flaky silver particles described above or silver particles of other shapes (for example, substantially spherical) (hereinafter referred to as "flaky silver particles, etc.") and silver covering the whisker-shaped potassium titanate described above. For example, it is also a suitable other aspect that both the flaky silver particles described above and silver covering the whisker-shaped potassium titanate described above are included in the first electrode layer 20.

[0045] In addition, another preferred aspect that can be adopted is that the above-mentioned silver is substantially spherical silver (Ag) particles, and a part of at least one of the substantially spherical silver (Ag) particles is embedded in the elastic layer 10. Further, another preferred aspect that can be adopted is that the above-mentioned silver is flaky silver particles or the like, and a part of at least one of the flaky silver particles or the like is embedded in the elastic layer 10, and / or the above-mentioned silver is silver covering potassium titanate (particularly, silver covering whisker-shaped potassium titanate), and a part of at least one of the silver covering potassium titanate (particularly, silver covering the whisker-shaped potassium titanate) is embedded in the elastic layer 10.

[0046] Specifically, the substantially spherical silver (Ag) particles, the flaky silver particles, and / or the silver covering potassium titanate (particularly, silver covering whisker-shaped potassium titanate) can play a role as a so-called "key" between the elastic layer 10 and the first electrode layer 20, thereby enhancing the integrity (bonding strength) between the elastic layer 10 and the first electrode layer 20 and further enhancing the conductivity of the entire medical devices 100, 100a.

[0047] Figures 7 and 8 are each an example of a cross-sectional SEM photograph showing a laminated structure of an elastic layer made of conductive polyurethane and a first electrode layer containing silver, silver chloride, and a resin (in this example, an acrylic resin). Note that "A" in Figures 7 and 8 indicates silver chloride (AgCl), "B" indicates substantially spherical silver (Ag) particles, and "C" indicates silver covering whisker-shaped potassium titanate.

[0048] As shown in Figures 7 and 8, it can be observed that a part of the substantially spherical silver (Ag) particles and / or a part of the silver covering potassium titanate enter the elastic layer side from the interface between the first electrode layer and the elastic layer. Therefore, since a state is formed in which a part of the substantially spherical silver (Ag) particles and / or a part of the silver covering potassium titanate are embedded in the elastic layer, it can be seen that a part of the substantially spherical silver (Ag) particles and / or a part of the silver covering potassium titanate can play a role as a so-called "key" between the elastic layer and the first electrode layer.

[0049] Also, FIGS. 7 and 8 show that when the first electrode layer covers substantially spherical silver (Ag) particles and / or silver covering potassium titanate, the distribution in the thickness direction of the substantially spherical silver (Ag) particles and / or the silver covering the potassium titanate in the first electrode layer is observed not to be localized. Further, upon analyzing other examples, it can be observed that when the first electrode layer contains flaky silver particles, the distribution in the thickness direction of the flaky silver particles in the first electrode layer is not localized.

[0050] Regarding the above-mentioned flaky silver particles and the like, it is a preferable embodiment that can be adopted that the thickness of the first electrode layer 20 is 2 μm or more (more preferably, 3 μm or more, still more preferably, 3.5 μm or more), and the mass ratio of the flaky silver particles and the like is 0.25 or more and 0.95 or less when the total amount of the flaky silver particles and the like and the above-mentioned silver chloride (AgCl) is taken as 1. The first electrode layer 20 having this feature can highly sensitively detect an electrical signal (typically, a biological signal) that may be generated by the movement of the surface undulations, unevenness, turning parts, bending parts, or stretching parts of the skin when the medical devices 100, 100a are arranged to contact the human skin.

[0051] Similarly, regarding the thickness of the first electrode layer 20 when silver covering the potassium titanate described above (especially silver covering the whisker-shaped potassium titanate) is adopted, similar to the thickness of the elastic layer 10, it is not limited as long as the required or purpose-appropriate conductivity as a medical device can be exhibited. From the viewpoint of highly sensitive detection of an electrical signal (typically, a biological signal), it is preferable that the thickness is 2 μm or more (more preferably 3 μm or more, still more preferably 3.5 μm or more). Further, when the total amount of the silver covering the potassium titanate (especially silver covering the whisker-shaped potassium titanate) and the above-described silver chloride (AgCl) is set to 1, a mass ratio of the silver covering the potassium titanate (especially silver covering the whisker-shaped potassium titanate) of 0.25 or more and 0.95 or less is a preferable embodiment that can be adopted. The first electrode layer 20 having this feature can highly sensitively detect an electrical signal (typically, a biological signal) that may be generated by the movement of the unevenness, concavity and convexity, turning part, bending part, or stretching part of the surface of the skin when the medical device 100 of this modified example or the medical device 100a of the modified example is arranged so as to contact the human skin.

[0052] In addition, the silver in the first electrode layer 20 being flaky silver particles or the like and / or silver covering potassium titanate, and the distribution of the silver in the thickness direction in the first electrode layer 20 being substantially uniform can also contribute to enhancing the conductivity of the first electrode layer 20 and thus the conductivity of the medical devices 100 and 100a.

[0053] In addition, an example of the average particle diameter (D50) of silver chloride (AgCl) in this modified example is about 1 μm or more and about 6 μm or less (more narrowly, about 1.5 μm or more and about 4.5 μm or less).

[0054] [Manufacturing method of the medical devices of the present embodiment and its respective modified examples] Next, a manufacturing method of the medical device 100 of the present embodiment and the medical device 100a of its modified example will be described.

[0055] [Step of forming the elastic layer 10 made of conductive polyurethane] First, a method for manufacturing the elastic layer 10 will be described. In order to incorporate the above-described conductive material (alternatively, conductive carbon black) into the polyurethane that mainly serves as a base material in the elastic layer 10, a means of mechanically stirring and mixing a composition for forming polyurethane (typically, organic polyisocyanate, polyol, catalyst) and the conductive material can be adopted.

[0056] [Forming step of the first electrode layer 20] The method for forming the first electrode layer 20 on one surface (the first surface 12) of the elastic layer 10 is not particularly limited. For example, after dissolving the above-mentioned silver (Ag), silver chloride (AgCl), and resin (typically, the first resin) in a glycol-based or ketone-based solvent, various coating methods or printing methods such as screen printing method, spin coating method, roll coating method, knife coating method, reverse roll coating method, bar coating method, blade coating method, spray coating method, etc. can be adopted.

[0057] As an example, the method for forming the first electrode layer 20 on the elastic layer 10 will be specifically described. FIG. 3 is a configuration diagram showing a part of the manufacturing apparatus 900 of the manufacturing process of the medical device 100 of the present embodiment. The manufacturing apparatus 900 shown in FIG. 3 is an example of an apparatus for forming the first electrode layer 20 with substantially the same thickness on the elastic layer 10.

[0058] As shown in FIG. 3, the manufacturing apparatus 900 of an example of the present embodiment is an apparatus that employs a film forming method called the knife coating method. The manufacturing apparatus 900 of the present embodiment includes a knife roll 93, a rotatable coating roll 92, and a storage unit 91 that stores a slurry 20a that is a raw material for the first electrode layer 20 in which silver (Ag), silver chloride (AgCl), and a resin (typically, the first resin) are mixed in the above-described solvent. Then, according to the manufacturing apparatus 900, as indicated by the dotted arrow, a layer of the slurry 20a is formed using the gap between the knife roll 93 and the coating roll 92 that is set to form the first electrode layer 20 with a predetermined thickness on one surface (the first surface 12) of the elastic layer 10 that is continuously fed by the rotation of the coating roll 92. After that, the first electrode layer 20 can be formed through a heat drying process (solvent removal and film forming process) of the slurry 20a. Note that the slurry 20a is supplied to the storage unit 91 according to the consumption amount as indicated by the white arrow.

[0059] In addition, as a part of the manufacturing process of the medical device 100a of the modification example (1) of the present embodiment, when forming the first electrode layer 20 in one or more island-like shapes on the elastic layer 10, for example, instead of the above-described knife coating method, it is an aspect that can be adopted to employ a screen printing method that utilizes a high-precision screen mask.

[0060] <Second Embodiment> The medical device 200 of the present embodiment is the same as the medical device 100 of the first embodiment, except that the second electrode layer 30 is uniformly arranged so as to substantially cover all of the surface (the second surface 14 in FIG. 2) of the elastic layer 10 in the medical device 100 of the first embodiment that is different from the first surface 12 and has substantially the same thickness. Therefore, the description that overlaps with the description of the first embodiment can be omitted.

[0061] FIG. 4 is a cross-sectional view showing the configuration of the medical device 200 of the present embodiment. As shown in FIG. 4, the medical device 200 includes a first electrode layer 20 on one surface (first surface 12) of the elastic layer 10 and a second electrode layer 30 on the other surface (second surface 14) of the elastic layer 10. And a typical example of the second electrode layer 30 is a layer made of silver (Ag).

[0062] The thickness of the layer made of silver (Ag) as the second electrode layer 30 is not limited as long as it does not substantially impair the above-described flexibility and followability in the elastic layer 10. From the viewpoint of preventing interference by external electromagnetic waves, from the viewpoint of significantly enhancing the conductivity of the medical device 100, particularly in the thickness direction of the elastic layer 10, and / or from the viewpoint of reducing the manufacturing cost of the medical device 200, it is a preferred aspect that the thickness of the layer is 2 μm or more and 30 μm or less, and more preferably 3 μm or more and 15 μm or less.

[0063] In addition, as another example of the second electrode layer 30, as long as the material does not substantially impair the conductivity of the elastic layer 10 and does not substantially impair the above-described flexibility and followability in the elastic layer 10, the material of the second electrode layer 30 or the material included in the second electrode layer 30 is not limited. Therefore, for example, instead of a thin layer made of silver (Ag), adopting copper (Cu) or nickel (Ni) is another aspect of the present embodiment.

[0064] <The Third Embodiment> The medical device 300 of this embodiment is the same as the medical device 200 of the second embodiment, except that a conductive gel layer 40 (for example, a gel-like layer containing an alkali metal halide containing sodium chloride (NaCl) or potassium chloride (KCl) as an electrolyte) is disposed or formed on the first electrode layer 20. Further, the medical device 300a of a modification of this embodiment is the same as the medical device 100 of the first embodiment, except that a conductive gel layer 40 is disposed or formed on the first electrode layer 20 in the medical device 100 and the medical device 100a of the first embodiment or a modification thereof. Therefore, descriptions overlapping with those of the first embodiment or the second embodiment may be omitted.

[0065] FIG. 5 is a cross-sectional view showing the configuration of the medical device 300 of this embodiment. FIG. 6 is a cross-sectional view showing the configuration of the medical device 300a of a modification of this embodiment.

[0066] First, as shown in FIG. 5, the medical devices 300 and 300a have a configuration in which a conductive gel layer 40 (for example, a conductive gel disclosed in JP-A-06-181894) is disposed on the first electrode layer 20.

[0067] It is a preferred aspect to employ a self-adhesive conductive gel that is physiologically acceptable (particularly suitable for contact with human skin) as the conductive gel layer 40. Further, it is a preferred aspect to employ a conductive gel that adheres to and detaches from human skin that is physiologically acceptable (particularly suitable for contact with human skin) as the conductive gel layer 40. The aforementioned self-adhesive conductive gel or detachable conductive gel can serve as a conductive adhesive part as a medical device.

[0068] Further, in an example of this embodiment, the conductive gel layer 40 can be disposed on the first electrode layer 20 by adopting various coating methods, lamination methods, transfer, pasting methods, or printing methods, similar to when the first electrode layer 20 is formed.

[0069] In the medical devices 300 and 300a, by adopting at least one selected from the group of silver covering the flaky silver particles and the whisker-shaped potassium titanate described above in the first embodiment for the first electrode layer 20, compared with substantially spherical silver (Ag) particles, even if silver chloride (AgCl) is granular such as substantially spherical, the unevenness on the surface of the first electrode layer 20 will be formed with higher accuracy. In particular, by adopting silver covering the whisker-shaped potassium titanate, the unevenness on the surface of the first electrode layer 20 will be formed with higher accuracy, in other words, more unevenness with a large height difference will be formed. As a result, the area of contact between the human skin and the conductive gel layer 40 will be substantially widened.

[0070] As a result, since the surface area of the entire first electrode layer 20 is substantially widened, electrolysis in the conductive gel layer 40, that is, conversion of an ion signal into an electronic signal becomes easier, so it is a preferable aspect that even a weaker biological signal can be acquired with high accuracy.

[0071] In addition, since the above-described first electrode layer 20 contains at least one selected from the group of silver covering the flaky silver particles and the whisker-shaped potassium titanate described above (among which, in particular, silver covering the whisker-shaped potassium titanate), it becomes possible to use the conductive gel with low skin irritation, so that the elderly, children, women, or patients with sensitive skin can continue to use it for a relatively long time.

[0072] The disclosure of each of the above embodiments and each of the above examples is for the purpose of explaining the embodiments and the examples, and is not for limiting the present invention. In addition, other modifications existing within the scope of the present invention including other combinations of the embodiments and the examples are also included in the scope of the claims.

Industrial Applicability

[0073] The medical device of the present invention can be widely applied to medical uses.

Explanation of Reference Numerals

[0074] 10 Elastic layer 12 First surface 14 Second surface 20 First electrode layer 30 Second electrode layer 40, 40a Conductive gel layer 91 Receiving part 92 Coating roll 93 Knife roll 100, 100a, 200, 300, 300a Medical device 900 Manufacturing apparatus for part of manufacturing process of medical device

Claims

1. An elastic layer made of conductive polyurethane, and a first electrode layer containing silver, silver chloride, and a resin on at least a part of one first surface of the elastic layer. A current can flow between the surface of the first electrode layer and the other second surface of the elastic layer. The silver includes silver covering potassium titanate. The potassium titanate has an aspect ratio of 10 or more and 240 or less, and A part of the silver covering at least one potassium titanate is buried in the elastic layer. A medical device.

2. The medical device according to claim 1, further comprising a second electrode layer made of silver on at least a part of the other second surface of the elastic layer. The medical device according to claim 1.

3. The silver includes flaky silver particles. The medical device according to claim 1 or claim 2.

4. The first electrode layer further comprises an adhesive portion that adhesively attaches to and detaches from the skin. The medical device according to claim 1 or claim 2.

5. The thickness of the first electrode layer is 2 μm or more and 30 μm or less. When the total amount of the flaky silver particles and the silver chloride is 1, the mass ratio of the flaky silver particles is 0.25 or more and 0.95 or less. The medical device according to claim 3.

6. The thickness of the first electrode layer is 2 μm or more and 30 μm or less. When the total amount of the silver covering potassium titanate and the silver chloride is 1, the mass ratio of the silver covering potassium titanate is 0.25 or more and 0.95 or less. The medical device according to claim 1 or claim 2.

7. The distribution of the silver covering potassium titanate in the thickness direction of the first electrode layer is not localized. The medical device according to claim 1 or claim 2.

8. The elastic layer has a tensile elongation rate of 50% or more. The medical device according to claim 1 or claim 2.

9. The glass transition temperature (Tg) of the elastic layer is less than 70°C. The medical device according to claim 1 or claim 2.

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