Biological signal detection device

Abstract

To provide a biological signal detector that achieves heightened sensitivity.SOLUTION: A biological signal detector includes a first electrode part 12A having a proximal 12A1 having a surface 12AF and a side face 12AS connected to the surface 12AF, and a stylet 12A2 projecting from the surface 12AF; a first wiring part 11A softer than the proximal 12A1; and a conductive adhesion layer 14 softer than the proximal 12A1, for connecting the proximal 12A1 to the first wiring part 11A.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a biological signal detection device. [Background technology]

[0002] A medical device for diagnosing a pathology in the skin of a subject is known. The medical device measures an impedance value in the skin and diagnoses a lesion present in the skin of the subject using the measured value. The medical device includes a conductive probe having a plurality of electrodes. Each electrode includes a base substrate and a plurality of microneedles formed integrally with the base substrate. The base substrate is a silicon wafer in an SOI wafer, and the microneedles are formed from the silicon wafer. Each microneedle has a length sufficient to penetrate the stratum corneum. When the impedance value in the skin is measured, each electrode is placed on the skin of the subject, and then each electrode is pressed against the skin, causing the microneedles to penetrate the stratum corneum (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2009-519062 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the skin of a living body, which is the target of puncturing with the microneedle, has elasticity. Therefore, when an external force for puncturing the microneedle acts on the skin by pressing the microneedle, the skin deforms according to the external force acting on the skin. In this respect, the base substrate formed of a silicon wafer has high rigidity, so it cannot sufficiently follow the deformation of the skin when puncturing with the microneedle. This causes the microneedle to not puncture the skin sufficiently, or the microneedle to easily come off during measurement. As a result, a significant amount of useful components are removed in the signal processing that removes unnecessary components from the detected biosignal, and useful components having sufficient strength for evaluation cannot be obtained. [Means for solving the problem]

[0005] To solve the above problem, a biosignal detection device includes an electrode portion having a base having a surface and a side connected to the surface, and a needle-shaped body protruding from the surface, a wiring portion softer than the base, and a conductive adhesive layer softer than the base and connecting the base to the wiring portion.

[0006] According to the above-mentioned biosignal detection device, since the wiring portion and the conductive adhesive layer are softer than the base portion, the wiring portion and the conductive adhesive layer for connecting the base portion to the wiring portion can deform to conform to the target to be punctured by the needle-shaped body. This makes it easier for the needle-shaped body to be punctured to the required depth compared to when the wiring portion and the conductive adhesive layer do not deform. Therefore, it is possible to increase the detection sensitivity of the biosignal detection device.

[0007] The above biosignal detection device may further include a substrate having a first surface and a second surface and being softer than the base, the wiring portion being located on the second surface, the substrate having a hole opening to the first surface, and the base being located inside the hole. According to this biosignal detection device, the wiring portion and the electrode portion are supported by the substrate, and the mechanical strength of the substrate makes it easier to maintain the connection between the electrode portion and the wiring portion.

[0008] In the above-mentioned biosignal detection device, the device may have a first surface and a second surface, and further include a substrate softer than the base, the wiring portion being located on the second surface, the biosignal detection device having a hole formed by a part of the wiring portion and a part of the substrate, the base being located inside the hole, and the conductive adhesive layer may connect the base to the part of the wiring portion.

[0009] According to the biosignal detection device, since the base is connected to a part of the wiring that forms the inner surface of the hole, the connection between the base and the wiring is located inside the hole, and therefore the connection between the part of the wiring and the base is more easily maintained than when the connection between the part of the wiring and the base is exposed to the outside.

[0010] In the biosignal detection device, the conductive adhesive layer may connect the side of the base to the inner surface of the hole. According to this biosignal detection device, the side of the base is connected to the inner surface of the hole by the soft conductive adhesive layer, so that when the base material deforms along the object to be punctured, the portion of the conductive adhesive layer located between the side of the base and the inner surface of the hole deforms, thereby maintaining the connection between the side of the base and the inner surface of the hole.

[0011] In the above biosignal detection device, the front surface and the first surface may be flush with each other. According to this biosignal detection device, the length of the part of the needle-shaped body protruding from the first surface of the base material can be maintained long, making it easier for the needle-shaped body to pierce the skin. Effect of the Invention

[0012] According to the present invention, the sensitivity of the biological signal detection device can be improved. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a plan view showing the structure of a biological signal detection device according to a first embodiment. [Diagram 2] 2 is a cross-sectional view showing the structure of the biological signal detection device shown in FIG. 1. [Diagram 3]3 is an enlarged cross-sectional view showing a part of the biosignal detection device shown in FIG. 2. [Figure 4] 5A to 5C are diagrams illustrating the operation of the biological signal detection device. [Diagram 5] 5A to 5C are diagrams illustrating the operation of the biological signal detection device. [Figure 6] 3A to 3C are process diagrams illustrating a manufacturing method of the biological signal detection device according to the first embodiment. [Figure 7] 3A to 3C are process diagrams illustrating a manufacturing method of the biological signal detection device according to the first embodiment. [Figure 8] 3A to 3C are process diagrams illustrating a manufacturing method of the biological signal detection device according to the first embodiment. [Figure 9] 3A to 3C are process diagrams illustrating a manufacturing method of the biological signal detection device according to the first embodiment. [Figure 10] FIG. 6 is a cross-sectional view showing the structure of a biological signal detection device according to a second embodiment. [Figure 11] 11 is an enlarged cross-sectional view showing a part of the biosignal detection device shown in FIG. 10. [Figure 12] 10A to 10C are process diagrams illustrating a manufacturing method of a biological signal detection device according to a second embodiment. [Figure 13] 10A to 10C are process diagrams illustrating a manufacturing method of a biological signal detection device according to a second embodiment. [Figure 14] 10A to 10C are process diagrams illustrating a manufacturing method of a biological signal detection device according to a second embodiment. [Figure 15] FIG. 11 is a cross-sectional view showing the structure of a biological signal detection device according to a third embodiment. [Figure 16] 16 is an enlarged cross-sectional view showing a part of the biological signal detection device shown in FIG. 15. [Figure 17] 10A to 10C are process diagrams illustrating a manufacturing method of a biological signal detection device according to a third embodiment. [Figure 18] FIG. 11 is a plan view showing a first modified example of the biological signal detection device. [Figure 19] FIG. 11 is a plan view showing a second modified example of the biological signal detection device. [Figure 20] FIG. 11 is a plan view showing a third modified example of the biological signal detection device. [Figure 21] FIG. 11 is a cross-sectional view showing a modified example of the biological signal detection device of the third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] [First embodiment] A first embodiment of a biosignal detection device will be described with reference to Figures 1 to 9. The structure of the biosignal detection device, the action of the biosignal detection device, and a manufacturing method for the biosignal detection device will be described below in order.

[0015] [structure] FIG. 1 shows the planar structure of a biosignal detection device as viewed from a viewpoint opposite to the plane on which a base material of the biosignal detection device extends.

[0016] 1, the biosignal detection device 10 includes wiring portions 11A and 11B, electrode portions 12A and 12B, and a base material 13. When viewed from a viewpoint facing the plane on which the base material 13 extends, the wiring portions 11A and 11B are located in a part of the base material 13. The wiring portions 11A and 11B have a linear shape. The wiring portions 11A and 11B have an expanded width in the portions connected to the electrode portions 12A and 12B compared to other portions.

[0017] The biosignal detection device 10 further includes a detection unit 20. The detection unit 20 detects an electrical signal generated in a living body. The detection unit detects, for example, a brain wave, which is an example of an electrical signal. The detection unit 20 receives an electrical signal via the electrode units 12A and 12B and the wiring units 11A and 11B.

[0018] FIG. 2 shows a cross-sectional structure of the biosignal detection device 10 along a plane that is perpendicular to the base material 13 and extends along the wiring portions 11A and 11B. As shown in FIG. 2, the biosignal detection device 10 includes a first wiring section 11A, a second wiring section 11B, a first electrode section 12A, and a second electrode section 12B. The first electrode section 12A is connected to the first wiring section 11A, and the second electrode section 12B is connected to the second wiring section 11B. The biosignal detection device 10 includes a first terminal 15A and a second terminal 15B. The first wiring section 11A is connected to the first terminal 15A, and the second wiring section 11B is connected to the second terminal 15B. Each of the terminals 15A and 15B is made of a material having electrical conductivity. Each of the terminals 15A and 15B is located on the substrate 13.

[0019] The detection unit 20 includes a main body 21, a first terminal 22A, and a second terminal 22B. Each of the terminals 22A and 22B is formed from a material having electrical conductivity. The first terminal 22A is connected to a first terminal 15A connected to the first wiring portion 11A. The second terminal 22B is connected to a second terminal 15B connected to the second wiring portion 11B. The first terminal 22A is configured to be able to be connected to the first terminal 15A and to be disconnected from the first terminal 15A. The second terminal 22B is configured to be able to be connected to the second terminal 15B and to be disconnected from the second terminal 15B. The first terminal 22A may be configured to be unable to be disconnected from the first terminal 15A, and the second terminal 22B may be configured to be unable to be disconnected from the second terminal 15B.

[0020] The main body 21 is capable of detecting electrical signals generated in a living body. The main body 21 may be capable of detecting brain waves as described above. Note that brain waves are minute electrical signals generated in the brain. The main body 21 may be capable of detecting, for example, a weak electric field generated in a muscle. Alternatively, the main body 21 may be capable of detecting minute electrical signals generated in the heart.

[0021] The main body 21 is equipped with a power source. The power source includes a battery and a DC / DC converter. The DC / DC converter converts the input voltage from the battery to a predetermined output voltage and supplies it to the functional units of the main body 21. When the main body 21 is driven by a battery, there is no need to connect the biosignal detection device 10 to an external power supply cable when measuring the subject's electrical signal, so it is possible to measure the biosignal without restricting the subject's movements.

[0022] The battery is preferably a secondary battery. The secondary battery may be, for example, a lithium secondary battery or an electric double layer capacitor. When a secondary battery is used, it is possible to supply power from an external source to the secondary battery located in the main body 21, thereby charging the secondary battery. Therefore, the secondary battery does not require battery replacement as in the case of using a primary battery, and the convenience of the biosignal detection device 10 can be improved.

[0023] The method of supplying power to the secondary battery may be a contact power supply method or a non-contact power supply method. When the contact power supply method is used, for example, a USB (universal serial bus) cable may be used to supply power to the secondary battery. The non-contact power supply method may be any of an electromagnetic induction method, an electrolytic coupling method, and a magnetic resonance method. From the viewpoint of improving the waterproofness of the biosignal detection device 10, it is preferable that the biosignal detection device 10 does not have an external terminal on its outer surface, and therefore it is preferable to adopt a non-contact power supply method as the power supply method.

[0024] The main body 21 includes a control unit. The control unit includes, for example, a CPU (central processing unit). The control unit controls the driving of the biological signal detection device 10. The control unit performs various processes on the signals input to the main body 21.

[0025] The main body 21 may include a display unit. When the main body 21 includes a display unit, the display unit is preferably located on the surface of the main body 21 opposite to the surface facing the base material 13. The display unit displays, for example, information related to the biosignal detected by the main body 21. The display unit may be, for example, a liquid crystal display panel.

[0026] The main body 21 may include a communication unit. The communication unit transmits data related to the biosignal detected by the main body 21 to an external device. The communication unit may be a mechanism for wired transmission or a mechanism for wireless transmission. When the communication unit is a mechanism for wireless transmission, the biosignal detection device 10 does not need to be connected to an external device by wire, so the subject's behavior is not restricted. Therefore, for example, it is possible to transmit the biosignal obtained from the subject to an external device in real time. The external device may be, for example, a personal computer, a mobile phone, or the like.

[0027] From the viewpoint of improving the waterproofness of the biosignal detection device 10, it is preferable that the biosignal detection device 10 does not have an external terminal on its outer surface, and therefore the communication unit is preferably a mechanism for wireless transmission. The communication unit may be, for example, a wireless communication module IC compatible with Bluetooth (registered trademark).

[0028] 3 shows the first electrode unit 12A and the surrounding structure of the first electrode unit 12A in the biosignal detection device 10. Note that the second electrode unit 12B and the surrounding structure of the second electrode unit 12B are located in a different position from the first electrode unit 12A in the biosignal detection device 10, but are structurally equivalent to the first electrode unit 12A. Therefore, detailed description of the second electrode unit 12B and the surrounding structure of the second electrode unit 12B will be omitted below.

[0029] As shown in FIG. 3, the first electrode portion 12A includes a base portion 12A1 and a needle-shaped body 12A2. In the example shown in FIG. 3, the first electrode portion 12A includes a plurality of needle-shaped bodies 12A2. The base portion 12A1 includes a front surface 12AF, a back surface 12AB opposite to the front surface 12AF, and a side surface 12AS connected to the front surface 12AF. The needle-shaped body 12A2 protrudes from the front surface 12AF. The first wiring portion 11A is softer than the base portion 12A1. The biosignal detection device 10 further includes a conductive adhesive layer 14. The conductive adhesive layer 14 is softer than the base portion 12A1, and connects the base portion 12A1 to the first wiring portion 11A.

[0030] The substrate 13 has a first surface 13F1 and a second surface 13F2. The second surface 13F2 is the surface opposite to the first surface 13F1. The substrate 13 is softer than the base portion 12A1. The first wiring portion 11A is located on the second surface 13F2. The substrate 13 has a hole 13H that opens to the first surface 13F1. The base portion 12A1 is located inside the hole 13H.

[0031] In the example shown in Fig. 3, the hole 13H penetrates the base material 13 in the thickness direction of the base material 13. As a result, the biosignal detection device 10 has a hole formed by a part of the first wiring portion 11A and a part of the base material 13. In detail, of the surfaces that define the hole, the bottom surface is a part of the first wiring portion 11A, and the side surface is a surface that defines the hole 13H of the base material 13. The base portion 12A1 is located inside the hole. The conductive adhesive layer 14 connects the base portion 12A1 to a part of the first wiring portion 11A.

[0032] The conductive adhesive layer 14 connects the side surface 12AS of the base 12A1 to the inner surface of the hole. The conductive adhesive layer 14 includes a portion located between the side surface 12AS of the base 12A1 and the side surface defining the hole 13H of the substrate 13. In this way, the conductive adhesive layer 14 connects the side surface of the base 12A1 to the side surface defining the hole. The conductive adhesive layer 14 further includes a portion located between the back surface 12AB of the base 12A1 and a part of the first wiring portion 11A. In this way, the conductive adhesive layer 14 connects the back surface 12AB of the base 12A1 to the bottom surface defining the hole.

[0033] In the biosignal detection device 10, the surface 12AF of the base 12A1 and the first surface 13F1 of the substrate 13 are flush with each other. In the present disclosure, flush with each other means that in a cross section perpendicular to the first surface 13F1, the distance between the surface 12AF and the first surface 13F1 is smaller than the height of the needle-shaped body 12A2. In the example shown in Fig. 3, the surface 12AF and the first surface 13F1 are located on the same plane.

[0034] As described above, the first wiring portion 11A and the substrate 13 are softer than the base portion 12A1 of the first electrode portion 12A. In the present disclosure, soft means that it is easy to expand and contract under load. Conversely, hard means that it is difficult to expand and contract under load. That is, soft means that at least the elasticity is relatively high, while hard means that at least the elasticity is relatively low. Therefore, the first wiring portion 11A and the substrate 13 have higher elasticity than the base portion 12A1. In the present disclosure, elasticity means tensile modulus of elasticity, i.e., Young's modulus. The tensile modulus of elasticity is measured by a method conforming to JIS K 7161-1:2015.

[0035] The conductive adhesive layer 14 may be softer than the first wiring portion 11A, or may be harder than the first wiring portion 11A. Alternatively, the conductive adhesive layer 14 may have the same softness as the first wiring portion 11A.

[0036] The substrate 13 is a sheet formed from a synthetic resin. The synthetic resin may be, for example, a silicone resin or a urethane resin. The thickness of the substrate 13 may be, for example, 10 μm or more and 1000 μm or less. The tensile modulus of the substrate 13 may be, for example, 10 MPa or less. The breaking elongation of the substrate 13 may be 0% or more and 100% or less. The breaking elongation is measured by a method conforming to the A method (strip method) specified in JIS L 1096:2010. When the substrate 13 has a length of 1 cm, it may have a degree of softness such that it has a distortion of 0.1 mm or more and 5 mm or less when a load of 4 kgf is applied to both ends.

[0037] The first wiring portion 11A is formed from a material having biocompatibility and conductivity. The first wiring portion 11A is formed from, for example, a silver paste. The silver paste contains a silicone resin and silver particles. In the silver paste, the silver particles are dispersed in the silicone resin. For example, when the entire silver paste is 100 mass %, the silver paste preferably contains 70 mass % or more of silver particles. The thickness of the first wiring portion 11A may be, for example, 0.001 μm or more and 1000 μm or less.

[0038] The first electrode portion 12A is formed of a main body portion 12AR and a conductive layer 12AM. The main body portion 12AR is formed of a first portion and a second portion. The first portion and the second portion are integrally molded. The first portion is a portion for forming the above-mentioned base portion 12A1, and is a portion having a flat plate shape. The second portion is a portion for forming the above-mentioned needle-shaped body 12A2, and is a portion protruding from the first portion. The main body portion 12AR is formed of a synthetic resin. The synthetic resin forming the main body portion 12AR is preferably biocompatible. The biocompatible synthetic resin may be, for example, polycarbonate, polystyrene, epoxy resin, polyethylene, polymethyl methacrylate, polyglycolic acid, polylactic acid, or the like.

[0039] In the main body 12AR, the thickness of the first portion may be, for example, 10 μm or more and 1000 μm or less. When viewed from a viewpoint facing the rear surface 12AB of the first electrode portion 12A, the area of ​​the first portion is, for example, 0.04 cm 2 More than 4cm 2 It may be the following:

[0040] The length of the second portion may be, for example, 50 μm to 300 μm, and the outer diameter of the second portion may be, for example, 10 μm to 250 μm. The distance between adjacent second portions may be, for example, 100 μm to 1400 μm, and is preferably 100 μm to 400 μm. The density of the second portions may be, for example, 10 fibers / cm. 2 More than 2000 pieces / cm 2 may be less than 200 fibers / cm2 More than 2000 pieces / cm 2 It is preferable that:

[0041] The second portion may have a shape that tapers away from the first portion. In a cross section taken along a plane perpendicular to the direction in which the second portion extends, the second portion may have a circular, elliptical, or polygonal shape. Examples of polygonal shapes include a star, a square, a triangle, and the like.

[0042] The conductive layer 12AM covers the entire body portion 12AR. The conductive layer 12AM may be formed of a metal, a semiconductor, an organic material, or a conductive polymer. Among these, the metal may be, for example, a nickel-titanium alloy, medical stainless steel, gold, titanium, nickel, iron, platinum, tin, chromium, copper, or the like. The semiconductor may be, for example, silicon. The organic material may be, for example, capacitive carbon, graphite, or the like. The conductive polymer may be, for example, highly conductive PEDOT.

[0043] The thickness of the conductive layer 12AM may be, for example, 0.05 μm or more and 5 μm or less. The base 12A1 of the first electrode portion 12A is formed from a first portion of the main body portion 12AR and a portion of the conductive layer 12AM that covers the first portion of the main body portion 12AR. Since the first portion is sufficiently thick compared to the conductive layer 12AM, the softness of the base 12A1 is determined by the softness of the first portion. In addition, since the thickness of the conductive layer 12AM is sufficiently thin compared to the length of the second portion of the main body portion 12AR, the length of the needle-shaped body 12A2 can be considered to be equal to the length of the second portion of the main body portion 12AR.

[0044] The conductive adhesive layer 14 is formed from various types of adhesives having conductivity. The adhesive includes a material having adhesiveness and a material having conductivity. The material having adhesiveness may be a synthetic resin. The synthetic resin may be, for example, an acrylic polymer material. The material having conductivity may be a metal paste or conductive particles. The metal paste may be, for example, a silver paste. The conductive particles may be metal particles or carbon particles. The metal particles may be, for example, copper-based particles, nickel-based particles, or silver-based particles. The silver-based particles may be, for example, silver particles or silver chloride particles. The carbon particles may be, for example, graphite or carbon nanotubes. From the viewpoints of conductivity, corrosion resistance, productivity, and the like, it is preferable that the conductive particles are silver particles.

[0045] [Effect] The operation of the biological signal detection device 10 will be described with reference to FIGS. 4, when the biosignal detection device 10 is used, the detection unit 20 is connected to the first wiring portion 11A and the second wiring portion 11B. The biosignal detection device 10 is placed on the skin Sk of the subject so that the first surface 13F1 of the base material 13 faces the skin Sk of the subject.

[0046] Next, as shown in Fig. 5, the first electrode portion 12A and the second electrode portion 12B are pressed against the skin Sk, so that the first electrode portion 12A and the second electrode portion 12B puncture the skin Sk. Since the wiring portions 11A, 11B and the conductive adhesive layer are softer than the base, the wiring portions 11A, 11B and the conductive adhesive layer for connecting the base to the wiring portions 11A, 11B can deform so as to conform to the skin Sk, which is the target of the needle-shaped body to puncture. This makes it easier for the needle-shaped body to puncture to the desired depth, compared to when the wiring portions 11A, 11B and the conductive adhesive layer are not deformed. Therefore, it is possible to increase the detection sensitivity of the biosignal detection device 10.

[0047] Moreover, in the biosignal detection device 10, the wiring parts 11A, 11B and the electrode parts 12A, 12B are supported by the substrate 13, so that the mechanical strength of the substrate 13 makes it easier to maintain the connection between the electrode parts 12A, 12B and the wiring parts 11A, 11B. Also, the base is connected to a part of the wiring parts 11A, 11B that forms the inner surface of the hole, so that the connection part between the base and the wiring parts 11A, 11B is located inside the hole. Therefore, the connection between the part of the wiring parts 11A, 11B and the base is easier to maintain than when the connection part between the part of the wiring parts 11A, 11B and the base is exposed to the outside. On the other hand, the side of the base is connected to the inner surface of the hole by the soft conductive adhesive layer. Therefore, when the substrate 13 is deformed along the skin Sk, the part of the conductive adhesive layer that is located between the side of the base and the inner surface of the hole is deformed, so that the connection between the side of the base and the inner surface of the hole is easier to maintain.

[0048] In addition, since the surface of the base 12A1 and the first surface 13F1 of the substrate 13 are flush with each other, it is possible to maintain a long length of the portion of the needle-shaped body protruding from the first surface 13F1 of the substrate 13. This makes it easier for the needle-shaped body to pierce the skin.

[0049] The stratum corneum of the skin Sk has an electrical resistance of about several MΩ. According to the biosignal detection device 10 of the present embodiment, the wiring parts 11A and 11B, the base material 13, and the conductive adhesive layer 14 are soft, and therefore can deform in accordance with the skin Sk, making it easy for the electrode parts 12A and 12B to puncture the skin Sk. This makes it possible to reduce the electrical resistance of the skin Sk to a level where the stratum corneum can be regarded as not being present. For example, it is possible to reduce the electrical resistance of the skin Sk to 10 kΩ or less.

[0050] Since the stratum corneum has a thickness of 10 μm or more and 20 μm or less, it is possible to reduce the electrical resistance of the skin Sk by puncturing the electrode parts 12A, 12B to a depth of 20 μm or more. However, if the puncture depth of the electrode parts 12A, 12B exceeds 1000 μm, the needle-shaped body may reach the subcutaneous tissue, which may cause the subject to feel pain. Therefore, it is preferable that the puncture depth of the electrode parts 12A, 12B is a depth that penetrates the stratum corneum but does not reach the subcutaneous tissue.

[0051] A conductive hydrogel may be used when the electrodes 12A and 12B are inserted into the skin of the subject. In this case, the conductive hydrogel is applied to the part of the skin Sk of the subject where the electrodes 12A and 12B are inserted. Then, the electrodes 12A and 12B are pressed against the part of the skin Sk to which the conductive hydrogel is applied. The conductive hydrogel swells the skin, making it easier to transmit electrical signals between the skin and the electrodes 12A and 12B.

[0052] [Manufacturing method] A method for manufacturing the biosignal detection device 10 will be described with reference to Figures 6 to 9. In the following, only matters related to the process of fixing the electrode units 12A and 12B to the base material 13 will be described in detail from the method for manufacturing the biosignal detection device 10. In the following, a process of fixing the first electrode unit 12A of the two electrode units 12A and 12B to the base material 13 will be described, but the second electrode unit 12B is also fixed to the base material 13 in the same manner as the first electrode unit 12A.

[0053] 6, the first electrode portion 12A is prepared. When preparing the first electrode portion 12A, first, a main body portion 12AR made of synthetic resin is formed. Next, a conductive layer 12AM is formed on the main body portion 12AR so as to cover the entire main body portion 12AR.

[0054] When forming the main body portion 12AR, first, an original plate of the main body portion 12AR is formed. Next, a duplicate plate is formed by transferring the original plate. Then, the main body portion 12AR is formed by transferring the duplicate plate. The material for forming the original plate may be at least one selected from the group consisting of metal, ceramic, semiconductor, organic material, and resin. Various methods can be used for forming the original plate. When forming the original plate, for example, a photolithography method, an etching method, an electroplating method, an electroless plating method, a screen printing method, a photolithography method, a laser ablation method, etc. can be used. The method for forming the conductive layer 12AM may be, for example, a vapor deposition method, a sputtering method, a CVD method, an epitaxy method, an electroplating method, a screen printing method, etc.

[0055] 9, the base material 13 on which the first wiring portion 11A is formed is prepared. In this process, the base material 13 is first prepared. Next, the first wiring portion 11A is formed on the second surface 13F2 of the base material 13. The method for forming the first wiring portion 11A may be, for example, an inkjet method, an etching method, a screen printing method, a dispenser method, or the like. Then, a hole 13H is formed in the base material 13, thereby exposing a part of the first wiring portion 11A to the hole 13H.

[0056] When fixing the first electrode portion 12A to the substrate 13, first, the conductive adhesive Ad is applied onto the substrate Sb (see FIG. 6). Next, the conductive adhesive Ad is spread over the entire substrate Sb using a scraper Sc (see FIG. 7). Then, the first electrode portion 12A is brought into contact with the conductive adhesive Ad so that the base portion 12A1 of the first electrode portion 12A is buried in the conductive adhesive Ad (see FIG. 8). After the first electrode portion 12A is lifted up from the conductive adhesive Ad, the first electrode portion 12A is placed together with the conductive adhesive Ad in the hole 13H (see FIG. 9). Next, the conductive adhesive Ad is cured to form a conductive adhesive layer 14 from the conductive adhesive Ad. As a result, the side surface 12AS of the base portion 12A1 is connected to the side surface defining the hole 13H, and the back surface 12AB of the base portion 12A1 is connected to a part of the first wiring portion 11A.

[0057] As described above, according to the first embodiment of the biological signal detection device, the following effects can be obtained. (1-1) The wiring parts 11A, 11B and the conductive adhesive layer 14 for connecting the base to the wiring parts 11A, 11B can be deformed to conform to the skin Sk that is the target of the needle-shaped body to be punctured. Therefore, the needle-shaped body can be easily punctured to the required depth compared to when the wiring parts 11A, 11B and the conductive adhesive layer are not deformed.

[0058] (1-2) Due to the mechanical strength of the base material 13, the connection between the electrode portions 12A, 12B and the wiring portions 11A, 11B is easily maintained. (1-3) Since the connection portions between the base and wiring portions 11A, 11B are located inside the holes, the connection between parts of wiring portions 11A, 11B and the base is easily maintained.

[0059] (1-4) When the substrate 13 deforms along the skin Sk, the portion of the conductive adhesive layer 14 located between the side of the base and the inner surface of the hole deforms, making it easier to maintain the connection between the side of the base and the inner surface of the hole.

[0060] (1-5) Since the length of the portion of the needle-shaped structure protruding from the first surface 13F1 of the base material 13 can be maintained long, the needle-shaped structure can be easily pierced into the skin. [Second embodiment] A second embodiment of the biosignal detection device will be described with reference to Figures 10 to 14. The second embodiment differs from the first embodiment in that the biosignal detection device has a hole penetrating the substrate and the wiring section. Therefore, while these differences will be described in detail below, structures in the second embodiment that are common to the first embodiment will be given the same reference numerals as in the first embodiment, and detailed descriptions of these structures will be omitted. The structure of the biosignal detection device and the manufacturing method will be described in order below.

[0061] [structure] The structure of the biosignal detection device will be described with reference to Figures 10 and 11. Figure 10 shows a cross-sectional structure of the biosignal detection device along a plane perpendicular to the plane on which the base material 13 extends.

[0062] As shown in FIG. 10, the biosignal detection device 30 includes wiring parts 11A and 11B, electrode parts 12A and 12B, a substrate 13, and a detection part 20, similar to the biosignal detection device 10 of the first embodiment. The biosignal detection device 30 further includes a first covering substrate 31A, a second covering substrate 31B, a first conductive part 32A, and a second conductive part 32B. The first covering substrate 31A covers the first wiring part 11A. The second covering substrate 31B covers the second wiring part 11B. It is preferable that each covering substrate 31A and 31B covers the entire wiring parts 11A and 11B covered by the covering substrate 31A and 31B, but only a part of the wiring parts 11A and 11B may be covered.

[0063] In a cross section perpendicular to the plane in which the base material 13 extends, the first conductive portion 32A is located between the first covering base material 31A and the first electrode portion 12A. In a cross section perpendicular to the plane in which the base material 13 extends, the second conductive portion 32B is located between the second covering base material 31B and the second electrode portion 12B.

[0064] 11 shows the first electrode unit 12A and the surrounding structure of the first electrode unit 12A in the biosignal detection device 30. Note that the second electrode unit 12B and the surrounding structure of the second electrode unit 12B are located in a different position from the first electrode unit 12A in the biosignal detection device 30, but are structurally equivalent to the first electrode unit 12A. Therefore, detailed description of the second electrode unit 12B and the surrounding structure of the second electrode unit 12B will be omitted below.

[0065] 11, in the biosignal detection device 30, the base material 13 has a hole 13H, and the first wiring portion 11A has a hole 11H. The hole 11H of the first wiring portion 11A is connected to the hole 13H of the base material 13. As a result, the two holes 11H, 13H form a through hole that penetrates the laminate of the first wiring portion 11A and the base material 13 in the thickness direction of the base material 13. In the biosignal detection device 30, the first wiring portion 11A is covered with the first covering base material 31A, so that a part of the first covering base material 31A is exposed in the through hole of the laminate described above.

[0066] The first electrode portion 12A is located in the hole 13H of the substrate 13. The first conductive portion 32A is located in the portion of the first covering substrate 31A exposed to the hole 11H of the first wiring portion 11A. The first conductive portion 32A is located in the hole 11H of the first wiring portion 11A. The conductive adhesive layer 34 is filled in the portion of the through hole where the first electrode portion 12A and the first conductive portion 32A are not located. As a result, the side surface 12AS of the base portion 12A1 is connected to the hole 13H of the substrate 13, and the back surface 12AB of the base portion 12A1 is connected to the first conductive portion 32A. The conductive adhesive layer 34 is softer than the base portion 12A1, similar to the conductive adhesive layer 14 of the first embodiment.

[0067] The first covering substrate 31A is softer than the base portion 12A1 of the first electrode portion 12A. The first covering substrate 31A is a sheet formed of a synthetic resin, similar to the substrate 13. The synthetic resin may be, for example, a silicone resin or a urethane resin. The thickness of the first covering substrate 31A may be, for example, 10 μm or more and 1000 μm or less. The tensile modulus of the first covering substrate 31A may be, for example, 10 MPa or less. The breaking elongation of the first covering substrate 31A may be, for example, 0% or more and 100% or less. The breaking elongation is measured by a method conforming to the A method (strip method) specified in JIS L 1096:2010.

[0068] The first conductive portion 32A is softer than the base portion 12A1 of the first electrode portion 12A. The first conductive portion 32A is formed from a material having biocompatibility and conductivity. The first conductive portion 32A is formed from, for example, a silver paste. The silver paste contains a silicone resin and silver particles. In the silver paste, the silver particles are dispersed in the silicone resin. For example, when the entire silver paste is 100 mass %, the silver paste preferably contains 70 mass % or more of silver particles. The thickness of the first conductive portion 32A may be, for example, 0.001 μm or more and 1000 μm or less.

[0069] [Manufacturing method] 12 to 14, a method for manufacturing the biosignal detection device 30 will be described. In the following, only matters related to the process of fixing the electrode units 12A and 12B to the base material 13 will be described in detail in the method for manufacturing the biosignal detection device 30. In the following, a process of fixing the first electrode unit 12A of the two electrode units 12A and 12B to the base material 13 will be described, but the second electrode unit 12B is also fixed to the base material 13 in the same manner as the first electrode unit 12A.

[0070] Prior to the step shown in FIG. 13, the first electrode portion 12A is prepared in the same manner as in the manufacturing method of the first embodiment. Then, the conductive adhesive Ad is applied around the first electrode portion 12A in the same manner as in the manufacturing method of the first embodiment. Prior to the step shown in FIG. 14, the base material 13 on which the first wiring portion 11A is formed is prepared in the same manner as in the manufacturing method of the first embodiment. Next, the hole 11H in the first wiring portion 11A and the hole 13H in the base material 13 are simultaneously formed to form a through hole penetrating the first wiring portion 11A and the base material 13 along the thickness direction of the base material 13. In the manufacturing method of this embodiment, since a through hole penetrating both the first wiring portion 11A and the base material 13 is formed, it is easier to form the through hole than when forming the hole 13H that penetrates only the base material 13.

[0071] When fixing the first electrode portion 12A to the substrate 13, first, the first conductive portion 32A is formed on the first covering substrate 31A. The method for forming the first conductive portion 32A may be, for example, an inkjet method, an etching method, a screen printing method, a dispenser method, or the like, similar to the method for forming the first wiring portion 11A. Next, a conductive adhesive Ad is applied to at least the side surface of the first conductive portion 32A (see FIG. 12). The method for applying the conductive adhesive Ad to the first conductive portion 32A may be the same method as the method for applying the conductive adhesive Ad to the first electrode portion 12A.

[0072] Then, the first electrode portion 12A coated with the conductive adhesive Ad is attached to the first conductive portion 32A by the conductive adhesive Ad (see FIG. 13). Next, the first covering base material 31A is placed on the first wiring portion 11A so that the first electrode portion 12A and the first conductive portion 32A are located in the through hole formed by the two holes 11H, 13H (see FIG. 14). Thereafter, the conductive adhesive Ad is cured to form a conductive adhesive layer 34 from the conductive adhesive Ad. As a result, the base portion 12A1 of the first electrode portion 12A is connected to the side surface defining the hole 13H, and the back surface 12AB of the base portion 12A1 is connected to the first conductive portion 32A.

[0073] As described above, according to the second embodiment of the biological signal detection device, in addition to the effects (1-1) to (1-5), the following effects can be obtained. (2-1) Since a through hole is formed that penetrates both first wiring portion 11A and base material 13, it is easier to form the through hole than when hole 13H that penetrates only base material 13 is formed.

[0074] [Third embodiment] A third embodiment of the biosignal detection device will be described with reference to Fig. 15 to Fig. 17. The third embodiment differs from the first embodiment in that the biosignal detection device has a hole penetrating the substrate and the wiring portion. Therefore, the following will describe these differences in detail, while the same reference numerals as in the first embodiment are used for structures common to the first embodiment, and detailed description of these structures will be omitted. The following will also describe the structure of the biosignal detection device and the manufacturing method thereof.

[0075] [structure] The structure of the biosignal detection device will be described with reference to Figures 15 and 16. Figure 15 shows a cross-sectional structure of the biosignal detection device along a plane perpendicular to the plane on which the base material 13 extends.

[0076] 15, similar to the biosignal detection device 10 of the first embodiment, the biosignal detection device 40 includes wiring portions 11A and 11B, electrode portions 42A and 42B, a base material 13, and a detection portion 20. The electrode portions 42A and 42B are connected to both the base material 13 and the wiring portions 11A and 11B.

[0077] 16 shows the first electrode section 42A and the surrounding structure of the first electrode section 42A in the biosignal detection device 40. Note that the second electrode section 42B and the surrounding structure of the second electrode section 42B are located in a different position from the first electrode section 42A in the biosignal detection device 40, but are structurally equivalent to the first electrode section 42A. Therefore, detailed description of the second electrode section 42B and the surrounding structure of the second electrode section 42B will be omitted below.

[0078] 16, in the biosignal detection device 40, the base material 13 has a hole 13H, and the first wiring portion 11A has a hole 11H. The hole 11H of the first wiring portion 11A is connected to the hole 13H of the base material 13. As a result, the two holes 11H, 13H form a through hole that penetrates the laminate of the first wiring portion 11A and the base material 13 in the thickness direction of the base material 13.

[0079] The first electrode portion 42A is located in the through hole. In the first electrode portion 42A, the thickness of the base portion 42A1 is approximately equal to the depth of the through hole. Therefore, the back surface 42AB of the base portion 42A1 is flush with the surface of the first wiring portion 11A opposite to the surface in contact with the substrate 13. In addition, the front surface 42AF of the base portion 42A1 is flush with the first surface 13F1 of the substrate 13.

[0080] In the first electrode portion 42A, the thickness of the first portion of the main body portion 42AR is thicker than the thickness of the first portion of the main body portion 12AR in the first embodiment. Meanwhile, the thickness of the conductive layer 42AM is equal to the thickness of the conductive layer 12AM in the first embodiment. As a result, the thickness of the base portion 42A1 is almost equal to the depth of the through hole described above. Also, the length of the needle-shaped body 42A2 is equal to the length of the needle-shaped body 12A2 in the first embodiment.

[0081] A conductive adhesive layer 44 is located between the side surface 42AS of the base 12A1 and the inner surface of the hole 11H, and between the side surface 42AS of the base 12A1 and the inner surface of the hole 13H. As a result, the first electrode portion 42A is connected to the first wiring portion 11A in the through hole described above.

[0082] [Manufacturing method] The structure of the biosignal detection device 40 will be described with reference to Fig. 17. In the following, only matters related to the process of fixing the electrode parts 42A, 42B to the base material 13 and the first wiring part 11A in the manufacturing method of the biosignal detection device 40 will be described in detail. In the following, the process of fixing the first electrode part 42A of the two electrode parts 42A, 42B to the base material 13 and the first wiring part 11A will be described, but the second electrode part 42B is also fixed to the base material 13 in the same manner as the first electrode part 42A.

[0083] 17, the first electrode portion 42A is prepared in the same manner as in the manufacturing method of the first embodiment. Then, the conductive adhesive Ad is applied to the periphery of the first electrode portion 42A in the same manner as in the manufacturing method of the first embodiment. At this time, the conductive adhesive Ad is applied only to the side surface 12AS of the base portion 12A1.

[0084] 17, a base material 13 on which a first wiring portion 11A is formed is prepared by a method similar to that of the manufacturing method of the first embodiment. Then, a hole 11H in the first wiring portion 11A and a hole 13H in the base material 13 are simultaneously formed to form a through hole penetrating the first wiring portion 11A and the base material 13 along the thickness direction of the base material 13. In the manufacturing method of the present embodiment, since a through hole penetrating both the first wiring portion 11A and the base material 13 is formed, it is easier to form the through hole than when a hole 13H penetrating only the base material 13 is formed.

[0085] 17, the first electrode portion 42A coated with the conductive adhesive Ad is placed in a through hole formed by the hole 13H of the substrate 13 and the hole 11H of the first wiring portion 11A. Then, the conductive adhesive Ad is cured to form a conductive adhesive layer 44 from the conductive adhesive Ad.

[0086] As described above, according to the third embodiment of the biological signal detection device, in addition to the effects (1-1) to (1-5), the following effects can be obtained. (3-1) Since a through hole is formed that penetrates both first wiring portion 11A and base material 13, it is easier to form the through hole than when hole 13H that penetrates only base material 13 is formed.

[0087] [Example of change] The above-described embodiment can be modified and implemented as follows. [Wiring section] 18, each of the first wiring portion 51A and the second wiring portion 51B included in the biosignal detection device 50 may have a bent line shape. In this case, even if stress caused by deformation of the base material 13 acts on the wiring portions 51A and 51B, the wiring portions 51A and 51B are less likely to break, compared to when the wiring portions 51A and 51B have a straight line shape.

[0088] [Electrode part] 19, in the biosignal detection device 60, a plurality of electrode units 62A, 62B may be connected to the wiring units 11A, 11B. On the premise that the total area of ​​the electrode units 62A, 62B is the same, the smaller the area of ​​one of the electrode units 62A, 62B, the easier it is to deform the electrode units 62A, 62B.

[0089] As shown in FIG. 20, in the biosignal detection device 70, the wiring sections 71A and 71B may be bifurcated along the direction from the detection section 20 toward the electrode sections 12A and 12B. In this case, in the wiring sections 71A and 71B, one of the portions after the bifurcation is a first wiring element, and the other is a second wiring element. The biosignal detection device 70 includes two first electrode sections 12A. One of the first electrode sections 12A is connected to the first wiring element, and the other first electrode section 12A is connected to the second wiring element. The biosignal detection device 70 also includes two second electrode sections 12B. One of the second electrode sections 12B is connected to the first wiring element, and the other second electrode section 12B is connected to the second wiring element.

[0090] In the electrode portion, the needle-shaped body may be configured so as to be attachable to and detachable from the base portion. [Conductive adhesive layer] 21, the conductive adhesive layer 44 of the third embodiment may include, in addition to a first portion 44A covering the side surface 42AS of the base 42A1, a second portion 44B covering the back surface 42AB of the base 42A1 and covering a part of the first wiring portion 11A. This makes it possible to expand the connection portion between the first wiring portion 11A and the conductive adhesive layer 44 compared to when the conductive adhesive layer 44 includes only the first portion 44A.

[0091] [Adhesive] When the biosignal detection device is used, an adhesive may be applied to the first surface 13F1 of the base material 13. Alternatively, the biosignal detection device may include an adhesive layer located on the first surface 13F1 of the base material 13. This can increase the adhesion of the base material 13 to the skin Sk.

[0092] [Biological signal detection device] The biosignal detection device may include a measurement unit that measures the electrical resistance of the skin Sk. The electrical resistance measured by the measurement unit is an index of the depth of puncture by the electrode unit. The measurement unit measures the electrical resistance at a portion of the skin Sk that is located between the two needle-shaped bodies that have punctured the skin Sk.

[0093] [Application] The biosignal detection device of the present disclosure can be used to improve the convenience of medical devices. The biosignal detection device can be applied to, for example, health care support devices, game devices, music devices, pet communication tools, and devices to prevent drivers from falling asleep at the wheel. [Explanation of symbols]

[0094] 10, 30, 40...Biological signal detection device 11A…1st wiring section 11B…Second wiring section 12A, 42A…1st electrode part 12A1,42A1…Base 12A2,42A2…needle body 12AB,42AB…Back side 12AF,42AF…Surface 12AS,42AS…side 12B,42B…Second electrode part 13...Base material 14,34,44...Conductive adhesive layer 31A…First coated substrate 31B...Second coated substrate 32A…first conductive part 32B…Second conductive part

Claims

1. an electrode portion including a base portion having a surface and a side surface connected to the surface, and a needle-shaped body protruding from the surface; A wiring portion that is softer than the base portion; a conductive adhesive layer that is softer than the base and connects the base to the wiring portion; a substrate having a first surface and a second surface and being softer than the base; the wiring portion is located on the second surface, the base material has a hole that opens to the first surface, the base is located within the hole; The electrode portion includes a main body portion formed of a synthetic resin and a conductive layer covering the main body portion, The main body has a flat plate shape and includes a first portion included in the base and a second portion protruding from the first portion and included in the needle-shaped body, The thickness of the first portion is equal to or greater than 10 μm and equal to or less than 1000 μm, The area of ​​the first portion is 0.04 cm 2 or more and 4 cm 2 or less. Biosignal detection device.

2. An electrode portion including a base having a surface and a side surface connected to the surface, and a needle-shaped body protruding from the surface; A wiring portion that is softer than the base portion; a conductive adhesive layer that is softer than the base and connects the base to the wiring portion; a substrate having a first surface and a second surface and being softer than the base; the wiring portion is located on the second surface, a hole formed by a part of the wiring portion and a part of the base material; the base is located within the hole; the conductive adhesive layer connects the base to the portion of the wiring portion; The electrode portion includes a main body portion formed of a synthetic resin and a conductive layer covering the main body portion, The main body has a flat plate shape and includes a first portion included in the base and a second portion protruding from the first portion and included in the needle-shaped body, The thickness of the first portion is equal to or greater than 10 μm and equal to or less than 1000 μm, The area of ​​the first portion is 0.04 cm 2 or more and 4 cm 2 or less. Biosignal detection device.

3. The conductive adhesive layer connects the side surface of the base to the inner surface of the hole. The biological signal detection device according to claim 1 or 2.

4. The surface and the first surface are flush with each other. The biological signal detection device according to claim 1 .

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