Biological sensor

Abstract

A biological sensor according to the present invention is attached to a living body and comprises: a sensor body that acquires biological information; a cover member having a cavity in which at least a part of the sensor body is accommodated and an opening that forms the cavity; a base material provided on the opening side of the cover member; a sensor-supporting base material that is provided on the side of the sensor body opposite the cover member side and on which the sensor body is installed; and a water absorption layer that is provided on a surface side of the sensor-supporting base material different from the cover member side and has an attachment surface to be attached to the living body. The water absorption layer is composed of a porous body, and in a plan view, at least a portion of the outer periphery of the water absorption layer has a first protruding portion protruding from the outer peripheries of the cover member, the base material, and the sensor-supporting base material.

Description

biosensor

[0001] The present invention relates to a biosensor.

[0002] Biosensors that measure bioinformation such as electrocardiogram waveforms, pulse waves, electroencephalograms, and electromyography are used in medical institutions such as hospitals and clinics, nursing homes, homes, etc. When measuring bioinformation, the biosensor is attached to the skin of a subject to acquire electrical signals related to the subject's bioinformation, thereby measuring the bioinformation.

[0003] As such a biosensor, for example, a biosensor has been disclosed that has a sensor body, electrodes, a first layer member formed by laminating a cover on an upper sheet so that the sensor body can be stored therein, and a second layer member attached to the surface of the first layer member facing the living body, in which the sensor body is installed and the electrodes are exposed (see, for example, Patent Document 1).

[0004] In this biosensor, a surface for attachment to the living body is formed by a first layer member, a second layer member, and an electrode, and a first adhesive layer provided on the surface of the first layer member facing the living body and a second adhesive layer provided on the surface of the second layer member facing the living body are attached to the skin, and bioinformation is acquired by an electrode attached to the first adhesive layer while exposed from the second layer member.

[0005] Japanese Patent No. 6947955

[0006] Here, with conventional biosensors such as the biosensor of Patent Document 1, if sweat generated from the skin accumulates between the skin and the attachment surface of the biosensor without being released, the adhesive strength of the first adhesive layer provided on the first layer member and the second adhesive layer provided on the second layer member will decrease, making the biosensor more likely to peel off from the skin, which may affect the attachment of the biosensor. Also, with conventional biosensors, when the biosensor is attached to the skin of a subject, sweat or the like may accumulate between the attachment surface of the biosensor and the skin, which may cause discomfort such as itching to the subject.

[0007] In order for a biosensor to remain attached to the subject's biological surface, such as the skin, and acquire electrical signals related to biological information while reducing discomfort to the subject, it is important that moisture such as sweat does not accumulate between the skin and the attachment surface of the biosensor, thereby reducing discomfort such as itching to the subject and keeping the sensor attached to the biological surface.

[0008] An object of one aspect of the present invention is to provide a biosensor that reduces discomfort to a subject during use and maintains adhesion to the surface of a living body.

[0009] One aspect of the present invention is a biosensor to be attached to a living body, comprising: a sensor body that acquires bioinformation; a cover member having a recess in which at least a portion of the sensor body is accommodated and an opening that forms the recess; a base material provided on the opening side of the cover member; a sensor support base material provided on the side opposite the cover member side of the sensor body and on which the sensor body is placed; and a water absorption layer provided on a side of the sensor support base material that is different from the cover member side and has an attachment surface to be attached to the living body, wherein the water absorption layer is made of a porous material, and has a first protrusion portion that protrudes beyond the outer periphery of the cover member, the base material, and the sensor support base material in at least a part of the outer periphery of the water absorption layer in a plan view.

[0010] One aspect of the biosensor according to the present invention can reduce discomfort felt by the subject during use and maintain adhesion to the surface of the living body.

[0011] FIG. 1 is a perspective view showing the overall configuration of a biosensor according to an embodiment of the present invention. FIG. 2 is a plan view showing examples of components of the biosensor. FIG. 3 is a longitudinal cross-sectional view of the biosensor, taken along II-I in FIG. 1. FIG. 4 is a plan view showing a schematic view of the biosensor. FIG. 5 is a lateral cross-sectional view of the biosensor, taken along II-II in FIG. 1. FIG. 6 is a diagram showing a portion of a bottom view of the biosensor. FIG. 7 is a partially enlarged view showing an example of a bottom view of an attachment layer. FIG. 8 is an explanatory view showing a state in which the biosensor of FIG. 1 is attached to the chest of a subject. FIG. 9 is a cross-sectional view showing an example of another configuration of the biosensor.

[0012] Hereinafter, embodiments of the present invention will be described in detail. To facilitate understanding of the description, the same components in each drawing are denoted by the same reference numerals, and duplicate descriptions will be omitted. The scale of each component in the drawings may differ from the actual scale. In this specification, unless otherwise specified, the symbol "to" indicating a range of values ​​means that the values ​​before and after it are included as the lower and upper limits.

[0013] <Biosensor> A biosensor according to an embodiment of the present invention will be described. Note that a biosensor refers to a human body (person) and animals such as cows, horses, pigs, chickens, dogs, and cats. The biosensor according to this embodiment can be suitably used for biosensors, particularly for human bodies. In this embodiment, a case where the biosensor is a human will be described as an example.

[0014] The biosensor according to this embodiment is a stick-on biosensor that is attached to a part of a living body (for example, the skin, scalp, or forehead) to measure biometric information. In this embodiment, a case will be described in which the biosensor is attached to human skin to measure an electrical signal (biological signal) related to the biometric information of the human.

[0015] FIG. 1 is a perspective view showing the overall configuration of a biosensor according to this embodiment. The left side of FIG. 1 shows the appearance of the biosensor according to this embodiment, and the right side of FIG. 1 shows the biosensor according to this embodiment in an exploded state, with each component of the biosensor. FIG. 2 is a plan view showing an example of each component of the biosensor. FIG. 3 is a longitudinal cross-sectional view of the biosensor, taken along line II of FIG. 1.

[0016] As shown in Figures 1 and 2, the biosensor 1 is a plate-like (sheet-like) member that is substantially rectangular in plan view and has arc-shaped longitudinal ends. As shown in Figures 2 and 3, the biosensor 1 includes a first layer member 10, an electrode 20, a sensor unit 30, a second layer member 40, and a water-absorbing layer 50. The first layer member 10, the electrode 20, the second layer member 40, and the water-absorbing layer 50 are stacked in this order from the first layer member 10 side toward the water-absorbing layer 50 side. In the biosensor 1, the electrode 20 and the water-absorbing layer 50 form an attachment surface for contacting skin 2, an example of a living body. The biosensor 1 attaches the attachment surface to the skin 2 and measures the potential difference (polarization voltage) between the skin 2 and the electrode 20 to measure an electrical signal (biological signal) related to the subject's biological information.

[0017] 1 to 3, a three-dimensional Cartesian coordinate system is used in three axes (X-axis, Y-axis, and Z-axis), with the widthwise direction of the biosensor 1 defined as the X-axis direction, the lengthwise direction defined as the Y-axis direction, and the height direction (thickness direction) defined as the Z-axis direction. The direction opposite (outside) the side of the biosensor 1 that is attached to a living organism (subject) (attachment side) is defined as the +Z-axis direction, and the attachment side is defined as the -Z-axis direction. In the following explanation, for convenience of explanation, the +Z-axis direction may be referred to as the upper side or top, and the -Z-axis direction may be referred to as the lower side or bottom, but this does not represent a universal vertical relationship.

[0018] The biological signal is an electrical signal that represents, for example, an electrocardiogram waveform, an electroencephalogram, a pulse, or the like.

[0019] Furthermore, the biosensor 1 does not need to include the electrodes 20 as long as the sensor unit 30 can measure a biosignal using infrared rays or the like. In this case, the storage space S may be formed by being surrounded by the first layer member 10 and the second layer member 40.

[0020] In manufacturing the biosensor 1, the present inventors noticed that in a biosensor including a first layer member 10 and a second layer member 40, moisture such as sweat is likely to accumulate between the second layer member 40 and the skin 2 depending on the moisture permeability of the second layer member 40, causing discomfort such as itching to the subject and affecting the adherence to the surface of the skin 2. After extensive study, the present inventors have found that a highly moisture permeable water-absorbent layer 50 is provided as an attachment layer for the skin 2 that is located closest to the skin 2 of the biosensor 1, and the outer shape of the water-absorbent layer 50 is made larger than the outer shapes of the first layer member 10 and the second layer member 40 in a plan view of the biosensor 1, so that the biosensor 1 is formed in a stepped shape so that the area increases from the first layer member 10 side to the water-absorbent layer 50 side in a side view. The inventors of the present application have discovered that if the sweat generated from the skin 2 is absorbed by the water-absorbing layer 50, it is possible to prevent moisture from remaining between the water-absorbing layer 50 and the skin 2, making it easier to release the moisture to the outside, and also to prevent a decrease in the adhesive strength of the water-absorbing layer 50. As a result, the inventors of the present application have found that it is possible to obtain a biosensor 1 that can be maintained attached to the skin 2 while reducing discomfort caused to the subject by moisture such as sweat.

[0021] 1 and 2, the first layer member 10 includes a cover member 11 and a cover sheet 12 laminated in this order. The first layer member 10 has an internal space so as to cover the sensor body 32 included in the sensor unit 30, and has a shape that protrudes in a generally dome-like shape in the height direction (+Z-axis direction) in Fig. 1. The cover sheet 12 has a shape that is larger than the cover member 11 in a plan view.

[0022] 3, the cover member 11 is located at the outermost position (+Z-axis direction) of the biosensor 1 and is adhered to the upper surface of the cover sheet 12. The cover member 11 has a protruding portion 111 in the center in the longitudinal direction (Y-axis direction) that protrudes in a generally dome shape toward the height direction (+Z-axis direction) in FIG. 1, and flat portions 112A and 112B provided on both ends in the longitudinal direction (Y-axis direction) of the cover member 11. The upper and lower surfaces of the protruding portion 111 and the upper and lower surfaces of the flat portions 112A and 112B are formed flat.

[0023] The protruding portion 111 has an opening formed on its inner side (adhering side) so as to have a recess 111a formed in a concave shape on the skin 2 side. The recess 111a may have a size sufficient to accommodate at least a part of the sensor unit 30. On the inner side (adhering side) of the protruding portion 111, the recess 111a on the inner surface of the protruding portion 111, the through-hole 12a of the cover sheet 12, and the second layer member 40 form a storage space S for accommodating the sensor unit 30.

[0024] The cover member 11 may generally be formed using a flexible material such as cross-linked rubber. Examples of cross-linked rubber include silicone rubber, fluororubber, urethane rubber, natural rubber, acrylic rubber, butadiene rubber, isoprene rubber, styrene-butadiene copolymer rubber, nitrile rubber, hydrogenated nitrile rubber, chloroprene rubber, ethylene-propylene copolymer rubber, chlorinated polyethylene rubber, chlorosulfonated polyethylene rubber, butyl rubber, and halogenated butyl rubber. The cover member 11 may also be formed by laminating the above-mentioned flexible material onto the surface of a base resin such as polyethylene terephthalate (PET) as a support. By forming the cover member 11 using the above-mentioned flexible material, the sensor unit 30 placed in the storage space S of the cover member 11 is protected, and impacts applied to the biosensor 1 from the top surface are absorbed, thereby softening the impact on the sensor unit 30.

[0025] The thickness of the top surface and side walls of the protruding portion 111 may be thicker than the thickness of the flat portions 112A and 112B, which allows the flexibility of the protruding portion 111 to be lower than the flexibility of the flat portions 112A and 112B, and makes it possible to protect the sensor unit 30 from external forces applied to the biosensor 1.

[0026] The thickness of the top surface and sidewall of the protruding portion 111 can be designed as appropriate and may be, for example, 1.5 mm to 3.0 mm. The thickness of the flat portions 112A and 112B can also be designed as appropriate and may be, for example, 0.5 mm to 1.0 mm.

[0027] The thin flat portions 112A and 112B are more flexible than the protruding portions 111, and therefore, when the biosensor 1 is attached to the skin 2, they are more likely to deform in accordance with deformation of the surface of the skin 2 due to bodily movements such as stretching, bending, and twisting. This makes it possible to alleviate the stress applied to the flat portions 112A and 112B when the surface of the skin 2 is deformed, and makes it difficult for the biosensor 1 to peel off from the skin 2.

[0028] The outer peripheries of the flat portions 112A and 112B may have a shape in which the thickness gradually decreases toward the edges. This can further increase the flexibility of the outer peripheries of the flat portions 112A and 112B, and improve the wearing comfort when the biosensor 1 is attached to the skin 2 compared to when the thickness of the outer peripheries of the flat portions 112A and 112B is not thin. As will be described later, the cover sheet 12 can reduce the stress applied to the flat portions 112A and 112B when the surface of the skin 2 is deformed.

[0029] The moisture permeability of the cover member 11 is not particularly limited, but is preferably 350 g / (m ２ ·day) or less. The moisture permeability of the cover member 11 is preferably 350 g / (m ２ If the time is less than 10 days, when water vapor generated by sweat or the like from the skin 2 to which the biosensor 1 is attached reaches the cover member 11, the water vapor can be released to the outside of the biosensor 1 through the cover member 11.

[0030] The method for measuring the moisture permeability of the cover member 11 is not particularly limited and any common method can be used. For example, the moisture permeability can be calculated by the following procedure. (1) Prepare a weighing bottle with an opening having a predetermined area A, and pour sufficient water into the weighing bottle so that the liquid level is below the opening. (2) Place part or all of the cover member 11 as a measurement sample over the entire opening of the weighing bottle, so as not to generate tension in the cover member 11, and secure the measurement sample to the weighing bottle, then seal the weighing bottle. (3) Measure the total mass M1 of the measurement sample, water, and weighing bottle immediately after sealing. (4) Leave the sealed weighing bottle for 24 hours under conditions of 40°C and 30% RH. (5) Measure the total mass M2 of the measurement sample, water, and weighing bottle after leaving it for 24 hours. (6) Calculate the moisture permeability P1 using the following formula (I): Moisture permeability P1 = (total mass M1 - total mass M2) / predetermined area A (I)

[0031] The moisture permeability measurement method may be similarly used for other components constituting the biosensor 1 unless otherwise specified.

[0032] The hardness (strength) of the cover member 11 can be designed to any appropriate value, for example, 10 to 40. If the hardness of the cover member 11 is within the above-mentioned preferred range, when the skin 2 stretches due to body movement, the cover sheet 12, the electrodes 20, and the second layer member 40 can easily deform in accordance with the movement of the skin 2 without being affected by the cover member 11. Note that hardness refers to Shore A hardness. In this specification, Shore A hardness refers to hardness measured in accordance with ISO 7619 (JIS K 6253-3:2012). As described in JIS K 6253-3:2012, "Vulcanized rubber and thermoplastic rubber - Determination of hardness - Part 3: Durometer hardness," the Shore A hardness measured by preparing a sheet sample of the cover member 11 can be used as the Shore A hardness of the cover member 11.

[0033] The cover member 11 preferably has a higher tensile strength than the cover adhesive layer 122 of the cover sheet 12. That is, the cover member 11 preferably has lower stretchability than the cover base material 121.

[0034] The method for measuring the tensile strength of the cover member 11 is not particularly limited, and a common method can be used. For example, a sample piece is prepared by cutting the cover member 11 to a predetermined size (e.g., 10 mm wide x 50 mm long). Next, both ends of the test piece in the longitudinal direction are clamped with a chuck so that the longitudinal length of the test piece is 20 mm. Then, using a common tensile tester, a peel test is performed in which the test piece is pulled under conditions of 23°C, a peel angle of 180°, and a peel rate of 300 mm / min. The test piece is pulled until the longitudinal length of the test piece reaches 22 cm, and the force (tensile force) applied to both ends of the test piece at 10% elongation (strain 0.1) is measured as the tensile strength (unit: N).

[0035] The same method for measuring the tensile strength may be used for other members constituting the biosensor 1 in the same way.

[0036] 3 , the cover sheet 12 is adhered to the underside of the cover member 11. The cover sheet 12 has a through hole 12a at a position facing the protrusion 111 of the cover member 11. The through hole 12a allows the sensor body 32 of the sensor unit 30 to be stored in the storage space S formed by the depression 111a on the inner surface of the cover member 11, the through hole 12a, and the second layer member 40 without being obstructed by the cover sheet 12.

[0037] The covering sheet 12 has a second protruding portion 12P that is larger outward than the outer periphery of the covering member 11 and smaller than the outer periphery of the water absorption layer 50 in a plan view, and is formed to have a shape that is larger outward than the outer periphery of the covering member 11 and smaller than the outer periphery of the water absorption layer 50. That is, the second protruding portion 12P is the outer periphery of the covering substrate 121 that is not covered by the covering member 11 in a plan view, and is larger than the outer periphery of the covering member 11 when the covering member 11 is attached and smaller than the outer periphery of the water absorption layer 50.

[0038] Since the second protruding portion 12P protrudes outward from the outer periphery of the cover member 11, the area of ​​attachment to the water-absorbing layer 50 can be made larger than when the cover sheet 12 is formed to the same size as the cover member 11.

[0039] Furthermore, because second protruding portion 12P is located at a position that protrudes outward from the outer periphery of cover member 11, when skin 2 deforms, the edge of the outer periphery of cover member 11 can be prevented from hitting second protruding portion 12P and coming into direct contact with skin 2. Furthermore, by preventing irritation to skin 2 by the outer periphery of cover member 11, the occurrence of pain or itching on skin 2 can be prevented.

[0040] Furthermore, when skin 2 stretches due to body movement, second protruding portion 12P functions as a buffer material that absorbs the stretch of skin 2 and can absorb some of the stretch of skin 2, thereby reducing stretching of the outer periphery of cover member 11. In other words, when skin 2 stretches due to body movement, second protruding portion 12P located on the outer periphery of cover sheet 12 stretches in response to the stretch of skin 2, thereby alleviating the stress applied to cover member 11, and therefore, the stretching of the outer periphery of cover member 11 can be reduced.

[0041] In this embodiment, the second protruding portion 12P protrudes from the entire outer periphery of the cover member 11, but only a portion of the second protruding portion 12P may protrude from the outer periphery of the cover member 11. In other words, the second protruding portion 12P may be provided only in a position on the biosensor 1 that is likely to peel off from the skin 2 due to body movement or the like.

[0042] The protrusion length (protrusion width, protrusion length) of the second protrusion portion 12P from the outer periphery of the cover sheet 12 is preferably 3 mm to 10 mm, more preferably 5 mm to 8 mm. A protrusion length of 3 mm to 10 mm of the second protrusion portion 12P can increase the adhesive area between the cover sheet 12 and the water-absorbent layer 50, thereby preventing delamination between the cover sheet 12 and the water-absorbent layer 50. Furthermore, the larger the adhesive area between the second protrusion portion 12P and the water-absorbent layer 50, the more moisture permeability in the thickness direction (Z direction) of the water-absorbent layer 50 is reduced, preventing sufficient sweat escape and reducing the effectiveness of reducing the itching experienced by the subject. A protrusion length of 5 mm to 8 mm of the second protrusion portion 12P can simultaneously prevent delamination between the cover sheet 12 and the water-absorbent layer 50 and reduce the itching experienced by the subject.

[0043] The protrusion length of the second protrusion portion 12P may be the length of protrusion from the outer periphery of the cover member 11. Furthermore, if there is a recess or protrusion on the outer periphery of the cover member 11 when the biosensor 1 is viewed in plan, the protrusion length of the second protrusion portion 12P may be the shortest distance.

[0044] The cover sheet 12 has a cover base material 121 as a base material, and cover adhesive layers 122 on both the top and bottom surfaces of the cover base material 121 .

[0045] The cover adhesive layer 122 has a first cover adhesive layer 122A to which the electrode 20 is attached on one side (lower side) of the cover base material 121 facing the electrode 20, and a second cover adhesive layer 122B provided on the side (upper side) opposite the one side facing the electrode 20 of the cover base material 121.

[0046] The cover sheet 12 may be configured as an adhesive tape including a cover substrate 121 and at least one of a first cover adhesive layer 122A and a second cover adhesive layer 122B.

[0047] The second protruding portion 12P may be composed of two components: a second protruding portion 121P of the cover substrate 121 and a second protruding portion 122P of the cover adhesive layer 122, which constitute the cover sheet 12. The second protruding portion 12P may be formed to include the second protruding portion 121P of the cover substrate 121. For example, the second protruding portion 12P may be composed of only the second protruding portion 121P. The second protruding portion 12P may also be composed of three layers: the second protruding portion 121P, the second protruding portion 122P, and a protruding portion of the second cover adhesive layer 122B. To prevent the second protruding portion 12P from sticking to clothing or the like or from attracting dirt and other debris, it is preferable that the second protruding portion 12P does not include a protruding portion of the second cover adhesive layer 122B.

[0048] (Cover Base Material) As shown in FIG. 3, the cover base material 121 is provided on the attachment side, which is the opening side, of the cover member 11. As shown in FIG. 1, the cover base material 121 is formed in a sheet shape. The cover base material 121 is flexible, waterproof, and breathable. The cover base material 121 being flexible, waterproof, and breathable makes it easy to stretch, and even if the water absorption layer 50 deforms in accordance with the deformation of the skin 2, the cover base material 121 can easily deform and maintain contact with the water absorption layer 50. In addition, water vapor generated by sweat, etc., from the skin 2 can be released to the outside of the biosensor 1 through the cover base material 121. This makes it easier for the cover sheet 12 to maintain its adhesion durability.

[0049] The cover substrate 121 may be a non-porous material without a porous structure, or a porous material with a porous structure, as long as it is flexible, waterproof, and moisture-permeable. If the cover substrate 121 is a non-porous material, it is easier to maintain the thin film and strength of the cover substrate 121, which is preferable. If the cover substrate 121 is a porous material, it is easier to release water vapor generated by sweat or the like from the skin 2 to which the biosensor 1 is attached to the cover substrate 121 to the outside of the biosensor 1, which is preferable.

[0050] As the non-porous body, a molded body formed into a sheet shape can be used.

[0051] The porous body may have a cell structure such as open cells, closed cells, or semi-closed cells. That is, the porous body may be a porous body manufactured by foam molding to form open cells (a porous body having an open cell structure), a porous body manufactured by foam molding to form closed cells (a porous body having a closed cell structure), or a porous body manufactured by foam molding to form semi-closed cells (a porous body having a semi-closed cell structure). Among these, a porous body having a closed cell structure is preferred in terms of achieving higher waterproofing while maintaining thinness and strength. Examples of porous bodies that can be used include foam sheets and nonwoven fabric sheets.

[0052] Examples of materials that can be used to form the cover substrate 121 include thermoplastic resins such as polyurethane resins, polystyrene resins, polyolefin resins, silicone resins, acrylic resins, vinyl chloride resins, and polyester resins, and flexible materials such as thermoplastic elastomers.

[0053] Examples of thermoplastic elastomers include polyurethane-based thermoplastic elastomers, polystyrene-based thermoplastic elastomers, polyolefin-based thermoplastic elastomers, polyester-based thermoplastic elastomers, polyvinyl chloride-based thermoplastic elastomers, polyamide-based thermoplastic elastomers, nitrile-based thermoplastic elastomers, nylon-based thermoplastic elastomers, fluororubber-based thermoplastic elastomers, polybutadiene-based thermoplastic elastomers, ethylene-vinyl acetate-based thermoplastic elastomers, chlorinated polyethylene-based thermoplastic elastomers, styrene-butadiene block copolymers or hydrogenated products thereof, and styrene-isoprene block copolymers or hydrogenated products thereof. These may be used alone or in combination of two or more. Among these, polyurethane-based thermoplastic elastomers are preferred.

[0054] When the cover substrate 121 is non-porous, specifically, a polyurethane sheet such as Esmar URS manufactured by Nippon Matai Co., Ltd. may be used.

[0055] The cover substrate 121 has a second protruding portion 121P. The second protruding portion 121P is a part of the second protruding portion 12P, and may protrude outward from the longitudinal and lateral peripheries of the cover member 11 and the second layer member 40 at the longitudinal and lateral peripheries of the cover substrate 121. Note that the second protruding portion 121P may protrude outward only from the longitudinal or lateral periphery of the cover substrate 121.

[0056] By including the second protruding portion 121P, the cover substrate 121 can have a larger contact area with the water absorption layer 50 than when the cover substrate 121 is formed to the same size as the cover member 11. Furthermore, because the cover substrate 121 is moisture permeable, it is easy to release water vapor generated by sweat or the like to the outside from the second protruding portion 121P. This prevents moisture such as sweat from accumulating between the cover substrate 121 and the first cover adhesive layer 122A, and prevents peeling between the cover substrate 121 and the first cover adhesive layer 122A.

[0057] The cover substrate 121 has low moisture permeability, which can prevent moisture such as sweat from entering the storage space S from between the cover member 11 and the cover substrate 121 through the second protruding portion 121P. Furthermore, the cover substrate 121 absorbs moisture, which can prevent deterioration of the cover substrate 121, and therefore can prevent peeling between the cover member 11 and the cover substrate 121.

[0058] The moisture permeability of the cover substrate 121 may be higher than that of the cover member 11, for example, 3600 g / (m ２ ·day) or less. The lower limit of the moisture permeability of the cover substrate 121 is 100 g / (m ２ The moisture permeability of the cover substrate 121 is 3600 g / (m ２ If the temperature is below 100°C (days), water vapor can be prevented from entering from the outside.

[0059] The method for measuring the moisture permeability of the cover substrate 121 is not particularly limited, and the same measuring method as that for the moisture permeability of the cover member 11 may be used.

[0060] The thickness of the cover substrate 121 can be set appropriately depending on the type, etc., but is preferably thicker than the thickness of the flat portions 112A and 112B of the cover member 11. If the thickness of the cover substrate 121 is thicker than the thickness of the flat portions 112A and 112B, it is possible to reduce irritation caused by the flat portions 112A and 112B coming into contact with the skin 2. The thickness of the cover substrate 121 is preferably 10 μm to 1.5 mm, for example.

[0061] When the cover substrate 121 is formed of a porous material such as a foam sheet, the thickness of the cover substrate 121 is preferably, for example, 0.5 mm to 1.5 mm.

[0062] When the cover substrate 121 is formed of a non-porous material such as a polyurethane sheet, the thickness of the cover substrate 121 is preferably, for example, 10 μm to 300 μm.

[0063] 3, the cover substrate 121 has a through hole 121a at a position facing the protruding portion 111 of the cover member 11. By providing the first cover adhesive layer 122A and the second cover adhesive layer 122B on the surface of the cover substrate 121 other than the through hole 121a, the through holes 122a and 122b can also be formed in the first cover adhesive layer 122A and the second cover adhesive layer 122B. The through holes 121a, 122a, and 122b form the through hole 12a.

[0064] ((Adhesive Layer for Cover)) As shown in FIG. 3 , the adhesive layer for cover 122 is provided on both the upper and lower surfaces of the base material for cover 121 .

[0065] As described above, the cover adhesive layer 122 has the first cover adhesive layer 122A and the second cover adhesive layer 122B.

[0066] 3, the first cover adhesive layer 122A is provided in a state of being attached to one surface of the cover substrate 121 that faces the electrode 20. The first cover adhesive layer 122A is located on the surface of the cover substrate 121 facing the skin 2 (in the −Z axis direction), and has the functions of adhering the cover substrate 121 and the electrode 20, adhering the cover substrate 121 and the sensor support substrate 41, and adhering the water absorption layer 50 and the cover substrate 121.

[0067] The first cover adhesive layer 122A may be moisture permeable, allowing water vapor generated by sweat or the like from the skin 2 to which the biosensor 1 is attached to be released to the cover substrate 121 or to the outside through the first cover adhesive layer 122A. This reduces the accumulation of sweat or water vapor at the interface between the first cover adhesive layer 122A and the electrode 20, thereby preventing the adhesive strength of the first cover adhesive layer 122A from decreasing due to moisture accumulated at the interface between the first cover adhesive layer 122A and the electrode 20.

[0068] The moisture permeability of the first cover adhesive layer 122A can be set arbitrarily, for example, to 1 g / (m ２ ·day) or more. The moisture permeability of the first cover adhesive layer 122A is preferably 10,000 g / (m ２ The moisture permeability of the first cover adhesive layer 122A may be 1 g / (m ２ If the first cover adhesive layer 122A is kept at 1 / 2 day or more, when the biosensor 1 is attached to the skin 2, sweat and the like transmitted through the first cover adhesive layer 122A can be transmitted to the outside.

[0069] The method for measuring the moisture permeability of the first cover adhesive layer 122A is not particularly limited, and the same measuring method as that for measuring the moisture permeability of the cover member 11 may be used.

[0070] The material for forming the first cover adhesive layer 122A may be a pressure-sensitive adhesive material, such as an acrylic adhesive or a silicone adhesive, and is preferably an acrylic adhesive.

[0071] The first cover adhesive layer 122A may be configured as an adhesive tape made of the above-mentioned material.

[0072] The first cover adhesive layer 122A may have a wavy pattern (web pattern) formed on its surface, in which recesses whose thickness is thinner than other portions (or zero thickness) are repeatedly and alternately arranged. For example, an adhesive tape having a web pattern formed on its surface may be used as the first cover adhesive layer 122A. By having a web pattern on its surface, the first cover adhesive layer 122A has both areas where the adhesive is likely to come into contact with the skin 2 and areas where it is unlikely to come into contact with the skin 2. Since the first cover adhesive layer 122A has both areas where the adhesive is present and areas where the adhesive is not present, the surface of the first cover adhesive layer 122A can be dotted with areas that are likely to come into contact with the skin 2. The moisture permeability of the first cover adhesive layer 122A tends to increase as the adhesive becomes thinner. Therefore, by forming a web pattern on the surface of the first cover adhesive layer 122A and having portions where the thickness of the adhesive is partially thin, it is possible to improve moisture permeability while maintaining adhesive strength compared to when the web pattern is not formed. Note that the shape of the recesses may be linear or circular, in addition to a wavy shape.

[0073] The thickness of the first cover adhesive layer 122A can be set arbitrarily, and is preferably 10 μm to 300 μm, for example. If the thickness of the first cover adhesive layer 122A is 10 μm to 300 μm, the biosensor 1 can be made thinner.

[0074] The first cover adhesive layer 122A has a second protruding portion 122P. The second protruding portion 122P is a part of the second protruding portion 12P and protrudes outward from the outer periphery of the cover member 11. This allows the covering sheet 12 to have a larger adhesion area to the water absorption layer 50 than when the covering sheet 12 is formed to the same size as the cover member 11.

[0075] 3, the second cover adhesive layer 122B is provided in a state of being attached to the surface (upper surface) opposite to the surface facing the electrode 20 of the cover substrate 121. The second cover adhesive layer 122B is attached to the upper surface of the cover substrate 121 at a position corresponding to the flat surface on the attachment side of the cover member 11 (in the −Z axis direction), and has the function of adhering the cover substrate 121 and the cover member 11 together.

[0076] The second cover adhesive layer 122B may be moisture permeable, similar to the first cover adhesive layer 122A. This allows water vapor generated by sweat or the like from the skin 2 to which the biosensor 1 is attached to be released to the outside through the second cover adhesive layer 122B. This reduces the accumulation of sweat or water vapor at the interface between the cover base material 121 and the second cover adhesive layer 122B, thereby preventing a decrease in the adhesive strength of the second cover adhesive layer 122B due to moisture accumulated at the interface between the cover base material 121 and the second cover adhesive layer 122B.

[0077] The moisture permeability of the second cover adhesive layer 122B can be set arbitrarily, for example, to 1 g / (m ２ The moisture permeability of the second cover adhesive layer 122B is preferably 10,000 g / (m ２ ·day) or less. ２ If the second cover adhesive layer 122B is kept at 100° C. for 10 days or more, when the biosensor 1 is attached to the skin 2, sweat and the like transmitted through the second cover adhesive layer 122B can be transmitted to the outside.

[0078] The method for measuring the moisture permeability of the second cover adhesive layer 122B is not particularly limited, and the same measuring method as that for measuring the moisture permeability of the cover member 11 may be used.

[0079] The second cover adhesive layer 122B is formed from a biocompatible material, such as an acrylic adhesive, a silicone adhesive, or a silicone tape, and is preferably a silicone adhesive.

[0080] The thickness of the second cover adhesive layer 122B can be set appropriately, and may be, for example, 10 μm to 300 μm.

[0081] 3, the electrode 20 is attached to the underside (-Z axis direction) of the first cover adhesive layer 122A, with a portion of the electrode 20 on the sensor body 32 side connected to the wiring 331A and 331B, sandwiched between the first cover adhesive layer 122A and the sensor connecting adhesive layer 42. The portion of the electrode 20 that is not sandwiched between the first cover adhesive layer 122A and the sensor connecting adhesive layer 42 comes into contact with a living body. When the biosensor 1 is attached to the skin 2, the electrode 20 comes into contact with the skin 2, thereby detecting a biological signal. The electrode 20 may be embedded in the sensor support base material 41 in an exposed state so as to be able to come into contact with the skin 2.

[0082] The electrode 20 is composed of a pair of electrodes 20A and 20B. As shown in Fig. 3, the electrode 20A is disposed on the left side of the drawing, and the electrode 20B is disposed on the right side of the drawing. One end (inner side) of the electrode 20A in the longitudinal direction (Y-axis direction) is in contact with the terminal portion 332A, and one end (inner side) of the electrode 20B in the longitudinal direction (Y-axis direction) is in contact with the terminal portion 332B. The pair of electrodes 20A and 20B have substantially the same shape.

[0083] One end of electrode 20A that contacts terminal 332A of sensor unit 30 and one end of electrode 20B that contacts terminal 332B of sensor unit 30 are referred to as facing portions 201A and 201B. The portions of electrode 20A that do not contact terminal 332A and the portions of electrode 20B that do not contact terminal 332B (the other end sides (outside) in the longitudinal direction (Y-axis direction)) are referred to as exposed portions 202A and 202B.

[0084] The electrode 20 may have any shape, such as a sheet shape.

[0085] The shape of the electrode 20 in a plan view is not particularly limited and may be designed into any shape appropriate for the application, etc. As shown in FIG. 2 , the electrode 20 may have, in a plan view, facing portions 201A and 201B at one end formed in a rectangular shape and exposed portions 202A and 202B at the other end formed in a semicircular shape. The length of the facing portions 201A and 201B in the width direction (Y-axis direction) is preferably greater than the maximum length of the exposed portions 202A and 202B in the width direction (Y-axis direction). This allows the areas of the facing portions 201A and 201B in contact with the terminal portions 332A and 332B of the sensor unit 30 to be reduced, while the areas of the exposed portions 202A and 202B in contact with the skin 2 to be increased.

[0086] The electrode 20 can be formed using a cured product of a conductive composition containing a conductive polymer and a binder resin, a metal, an alloy, or the like. Among these, from the viewpoint of subject safety, such as preventing allergic reactions when the electrode 20 is applied to a living body, it is preferable to form the electrode 20 using a cured product of the conductive composition. The electrode 20 may also be an adhesive electrode sheet in which a cured product of the conductive composition is formed into a sheet shape.

[0087] Examples of conductive polymers that can be used include polythiophene-based conductive polymers, polyaniline-based conductive polymers, polyacetylene-based conductive polymers, polypyrrole-based conductive polymers, polyphenylene-based conductive polymers, and derivatives thereof, as well as composites of these. Among these, composites in which polythiophene is doped with polyaniline as a dopant are preferred. Among composites of polythiophene and polyaniline, it is more preferred to use PEDOT / PSS, in which poly(3,4-ethylenedioxythiophene) (also referred to as PEDOT) is doped as the polythiophene with polystyrene sulfonic acid (poly4-styrenesulfonate; PSS) as the polyaniline, because of its lower contact impedance with a living body and high conductivity.

[0088] The binder resin may be a water-soluble polymer or a water-insoluble polymer, etc. Examples of the water-soluble polymer include hydroxyl group-containing polymers such as polyvinyl alcohol (PVA) and modified PVA.

[0089] The conductive composition may contain various general additives such as a crosslinking agent and a plasticizer in any appropriate proportion. Examples of the crosslinking agent include aldehyde compounds such as sodium glyoxylate. Examples of the plasticizer include glycerin, ethylene glycol, and propylene glycol.

[0090] As the metal and alloy, general metals and alloys such as Au, Pt, Ag, Cu, and Al can be used.

[0091] The thickness of the electrode 20 may be any appropriate value, for example, 10 μm to 100 μm. When the thickness of the electrode 20 is within the above preferred range, the electrode 20 can have sufficient strength and flexibility.

[0092] The thickness of the electrode 20 refers to the length in the direction perpendicular to the surface of the electrode 20. The thickness of the electrode 20 is, for example, the thickness measured at an arbitrary location on the cross section of the electrode 20, and when measurements are taken at multiple locations at the same location, the thickness may be the average value of the thicknesses at these measurement locations.

[0093] (Sensor Section) As shown in FIG. 2, the sensor section 30 has a flexible substrate 31, a sensor body 32, and connection sections 33A and 33B connected to the sensor body 32.

[0094] The flexible substrate 31 is a resin substrate on which various components for acquiring biometric information are mounted, and a sensor body 32 and connection portions 33A and 33B are arranged on the flexible substrate 31. Note that the flexible substrate 31 may be configured integrally with the connection portions 33A and 33B.

[0095] As shown in FIG. 2, the sensor main body 32 has a component mounting section 321 which is a control section, and a battery mounting section 322, and acquires biological information.

[0096] The component mounting unit 321 has various components mounted on the flexible substrate 31, such as a CPU and integrated circuit that process biosignals acquired from a living body to generate biosignal data, a switch SW that activates the biosensor 1, a flash memory that stores the biosignals, and a light-emitting element, and acquires bioinformation. Circuit examples using the various components are omitted. The component mounting unit 321 operates using power supplied from a battery 34 mounted in the battery mounting unit 322.

[0097] The component mounting unit 321 transmits the information to an external device such as an operation checking device that checks the initial operation and a reading device that reads the biometric information from the biometric sensor 1 via wired or wireless communication.

[0098] The battery mounting section 322 is disposed between the connection section 33A and the component mounting section 321, and supplies power to the integrated circuits and the like mounted on the component mounting section 321. As shown in FIG. 2, a battery 34 is mounted in the battery mounting section 322.

[0099] The connection portions 33A and 33B have wirings 331A and 331B respectively connected to the sensor body 32 in the longitudinal direction (Y-axis direction) of the sensor body 32, and terminal portions 332A and 332B provided at the tip side of the wirings 331A and 331B and connected to the electrodes 20.

[0100] As shown in Fig. 3, one end of the wires 331A and 331B is connected to the terminal portions 332A and 332B, respectively. As shown in Fig. 2, the other end of the wire 331A is connected to a switch SW or the like mounted on the component mounting portion 321 along the outer periphery of the sensor main body 32. The other end of the wire 331B is connected to a switch SW or the like mounted on the component mounting portion 321.

[0101] As shown in Figure 3, the terminal portions 332A and 332B are arranged in a state where one end is connected to the wiring 331A and 331B, and the upper surface of the other end is in contact with the electrode 20 and is sandwiched between the first layer member 10 and the second layer member 40.

[0102] A known battery can be used as the battery 34. For example, a coin-type battery such as CR2025 can be used as the battery 34.

[0103] [Second Layer Member] As shown in Fig. 3 , the second layer member 40 is provided on the attachment surface side of the electrode 20 and the sensor unit 30 and is a support substrate on which the sensor unit 30 is installed. As shown in Figs. 1 and 2 , the outer shape of both sides of the second layer member 40 in the width direction (X-axis direction) may be substantially the same as the outer shape of both sides of the first layer member 10 in the width direction (X-axis direction). The length (Y-axis direction) of the second layer member 40 is shorter than the lengths (Y-axis direction) of the cover member 11 and the cover sheet 12. As shown in Fig. 3 , both longitudinal ends of the second layer member 40 are positioned so that the wiring 331A and 331B of the sensor unit 30 are sandwiched between the second layer member 40 and the cover sheet 12 and overlap with a portion of the electrode 20.

[0104] 4 , the second layer member 40 has a third protrusion 40P on the outer periphery of the second layer member 40 in the width direction (X-axis direction) that is larger than the outer periphery of the cover member 11 and smaller than the outer periphery of the covering sheet 12 in a plan view. The third protrusion 40P is larger than the outer periphery of the cover member 11 and smaller than the outer periphery of the covering sheet 12. That is, the third protrusion 40P is the outer periphery of the second layer member 40 that is not covered by the covering member 11 in a plan view, and is larger than the outer periphery of the cover member 11 and smaller than the outer periphery of the covering sheet 12 when the covering member 11 is attached. The third protrusion 40P is provided over the entire outer periphery of the second layer member 40 in the width direction (X-axis direction), but may be provided only on a portion of the outer periphery of the second layer member 40 in the width direction (X-axis direction).

[0105] Since the third protrusion portion 40P protrudes outward from the outer periphery of the cover member 11 in the width direction (X-axis direction), the adhesive area between the second layer member 40 and the cover sheet 12 can be increased compared to when the cover sheet 12 is formed to approximately the same size as the cover member 11.

[0106] In this embodiment, the third protrusion portion 40P protrudes from the entire outer periphery of the cover member 11 in the width direction (X-axis direction), but only a portion of the third protrusion portion 40P may protrude from the outer periphery of the cover member 11.

[0107] The protrusion length of the third protrusion 40P from the outer periphery of the cover member 11 is preferably 3 mm to 10 mm, more preferably 5 mm to 8 mm. A protrusion length of 3 mm to 10 mm of the third protrusion 40P can increase the adhesive area between the second layer member 40 and the cover sheet 12, thereby preventing delamination between the cover sheet 12 and the second layer member 40. Furthermore, the larger the adhesive area between the third protrusion 40P and the cover member 11, the more moisture permeability in the thickness direction (Z direction) of the second layer member 40 is reduced, preventing sufficient sweat escape and reducing the effectiveness of reducing the itching experienced by the subject. A protrusion length of 5 mm to 8 mm of the third protrusion 40P can simultaneously prevent delamination between the cover sheet 12 and the second layer member 40 and reduce the itching experienced by the subject.

[0108] The protrusion length of the third protrusion portion 40P may be the protrusion length from the outer periphery of the cover member 11, similar to the second protrusion portion 12P. Furthermore, if there is a recess or protrusion on the outer periphery of the cover member 11 when the biosensor 1 is viewed in plan, the protrusion length of the third protrusion portion 40P may be the shortest distance.

[0109] 5 , the second layer member 40 includes a sensor support substrate 41, a sensor connecting adhesive layer 42 provided on the upper surface of the sensor support substrate 41, and a sensor supporting adhesive layer 43 provided on the lower surface of the sensor support substrate 41. The sensor support substrate 41, the sensor connecting adhesive layer 42, and the sensor supporting adhesive layer 43 may be formed to have the same shape in a plan view. The waterproof property and moisture permeability, and adhesive property can be varied depending on the types of the sensor support substrate 41, the sensor connecting adhesive layer 42, and the sensor supporting adhesive layer 43, the area of ​​the second layer member 40 in a plan view, and the like. The second layer member 40 can have different waterproof property and moisture permeability, as well as different adhesive properties, depending on the area of ​​the attachment surface of the sensor connecting adhesive layer 42 and the sensor supporting adhesive layer 43.

[0110] As shown in Figure 5, the third protrusion portion 40P may be composed of three components: a third protrusion portion 41P of the sensor support base material 41 that constitutes the second layer member 40, a third protrusion portion 42P of the sensor connecting adhesive layer 42, and a third protrusion portion 43P of the sensor support adhesive layer 43.

[0111] (Sensor Supporting Base) The sensor supporting base 41 can be formed using a flexible resin having appropriate stretchability, flexibility, and toughness. Examples of materials that can be used to form the sensor support substrate 41 include polyester-based resins such as polyethylene terephthalate (PET), polybutylene terephthalate, polytrimethylene terephthalate, polyethylene naphthalate, and polybutylene naphthalate; acrylic resins such as polyacrylic acid, polymethacrylic acid, polymethyl acrylate, polymethyl methacrylate (PMMA), polyethyl methacrylate, and polybutyl acrylate; polyolefin-based resins such as polyethylene and polypropylene; polystyrene-based resins such as polystyrene, imide-modified polystyrene, acrylonitrile-butadiene-styrene (ABS) resin, imide-modified ABS resin, styrene-acrylonitrile copolymer (SAN) resin, and acrylonitrile-ethylene-propylene-diene-styrene (AES) resin; polyimide-based resins; polyurethane-based resins; silicone-based resins; and thermoplastic resins such as polyvinyl chloride and vinyl chloride-vinyl acetate copolymer resins. Among these, polyolefin-based resins and PET are preferred. These thermoplastic resins are waterproof and do not allow moisture or water vapor to pass through (have low moisture permeability). Therefore, by forming the sensor support base material 41 using these thermoplastic resins, it is possible to prevent sweat or water vapor generated from the skin 2 from passing through the sensor support base material 41 and entering the flexible substrate 31 of the sensor unit 30 when the biosensor 1 is attached to the skin 2.

[0112] The sensor support base material 41 is preferably formed in a flat plate shape because the sensor unit 30 is placed on the upper surface thereof via the sensor connecting adhesive layer 42 .

[0113] The thickness of the sensor support substrate 41 can be selected as appropriate and may be, for example, 1 μm to 300 μm.

[0114] The sensor support base 41 has a third protrusion 41P. The third protrusion 41P is a part of the third protrusion 40P, and may protrude outward from the outer periphery of the sensor support base 41 in the short side direction beyond the outer periphery of the cover member 11 in the short side direction.

[0115] By having the third protrusion portion 41P, the sensor support substrate 41 can increase the adhesive area between the second layer member 40 having the sensor support substrate 41 and the cover sheet 12 compared to when the sensor support substrate 41 is formed to the same size as the cover member 11.

[0116] (Sensor-Connecting Adhesive Layer) As shown in FIG. 3 , the sensor-connecting adhesive layer 42 is provided on the surface (upper surface) of the sensor support substrate 41 facing the cover member 11 (in the +Z-axis direction), and the sensor unit 30 is adhered thereto. Both longitudinal ends of the sensor-connecting adhesive layer 42 of the second layer member 40 are provided in positions facing the facing portions 201A and 201B of the electrode 20. This allows the facing portions 201A and 201B of the electrode 20 and the terminal portions 332A and 332B to be sandwiched between the cover sheet 12 and the second layer member 40 in a pressed state, thereby establishing electrical continuity between the electrode 20 and the terminal portions 332A and 332B. The sensor-connecting adhesive layer 42 is not necessarily required or even optional.

[0117] The sensor connecting adhesive layer 42 can be formed using the same material as the sensor supporting adhesive layer 43, and therefore details thereof will be omitted.

[0118] The sensor-connecting adhesive layer 42 preferably has pressure-sensitive adhesive properties, which allows the electrode 20 and the sensor unit 30 to be easily attached by pressing them against the sensor-connecting adhesive layer 42.

[0119] The material of the sensor connecting adhesive layer 42 is not particularly limited as long as it is a material having pressure-sensitive adhesive properties, and examples thereof include an acrylic pressure-sensitive adhesive, a silicone pressure-sensitive adhesive, etc. Preferably, an acrylic pressure-sensitive adhesive or the like can be used.

[0120] The acrylic pressure-sensitive adhesive preferably contains an acrylic polymer as a main component. The acrylic polymer can function as a pressure-sensitive adhesive component. As the acrylic polymer, a polymer obtained by polymerizing a monomer component containing a (meth)acrylic acid ester such as isononyl acrylate or methoxyethyl acrylate as a main component and optionally containing a monomer copolymerizable with the (meth)acrylic acid ester such as acrylic acid can be used.

[0121] The acrylic pressure-sensitive adhesive preferably further contains a carboxylic acid ester. The carboxylic acid ester functions as a pressure-sensitive adhesive strength adjuster that reduces the pressure-sensitive adhesive strength of the acrylic polymer and adjusts the pressure-sensitive adhesive strength of the sensor-connecting adhesive layer 42. The carboxylic acid ester may be a carboxylic acid ester that is compatible with the acrylic polymer. Examples of the carboxylic acid ester that may be used include triglycerides of fatty acids.

[0122] The acrylic pressure-sensitive adhesive may contain a crosslinking agent, if necessary. The crosslinking agent is a crosslinking component that crosslinks the acrylic polymer. Examples of crosslinking agents include polyisocyanate compounds (polyfunctional isocyanate compounds), epoxy compounds, melamine compounds, peroxide compounds, urea compounds, metal alkoxide compounds, metal chelate compounds, metal salt compounds, carbodiimide compounds, oxazoline compounds, aziridine compounds, and amine compounds. Among these, polyisocyanate compounds are preferred. These crosslinking agents may be used alone or in combination.

[0123] The sensor connecting adhesive layer 42 may be formed of an adhesive tape made of the above-mentioned material.

[0124] The sensor connecting adhesive layer 42 may be moisture permeable, allowing water vapor and the like generated from the skin 2 to which the biosensor 1 is attached to escape to the outside from the side surfaces of the sensor connecting adhesive layer 42.

[0125] The moisture permeability of the sensor connecting adhesive layer 42 is not particularly limited and can be set appropriately, for example, to 300 g / (m ２ ・day)~10000g / (m ２If the moisture permeability of sensor-connecting adhesive layer 42 is within the above-mentioned preferred range, sweat generated from skin 2 or water vapor generated by sweat can be transmitted from sensor-connecting adhesive layer 42 to the outside.

[0126] The method for measuring the moisture permeability of the sensor-connecting adhesive layer 42 is not particularly limited, and a general measuring method may be used, and a measuring method similar to the method for measuring the moisture permeability of the cover member 11 may be used.

[0127] The adhesive strength of the sensor connecting adhesive layer 42 is sufficient to maintain the adhesion of the electrode 20 and the sensor unit 30, and is preferably, for example, 2.5 N / 10 mm to 5.0 N / 10 mm. If the adhesive strength of the sensor supporting adhesive layer 43 is within the above-mentioned preferred range, the electrode 20 and the sensor unit 30 can be maintained in a state where they are stably attached to the sensor supporting adhesive layer 43.

[0128] The method for measuring the adhesive strength of the sensor-connecting adhesive layer 42 is not particularly limited, and a general measuring method may be used, and a measuring method similar to the method for measuring the adhesive strength of the cover member 11 may be used.

[0129] The adhesive strength of the sensor-linking adhesive layer 42 may be measured, for example, as follows. That is, a laminate having the sensor-linking adhesive layer 42 formed on one main surface of the sensor-supporting substrate 41 is cut to cut out a sample piece (10 mm wide x 50 mm long) in which the sensor-linking adhesive layer 42 is laminated to the sensor-supporting substrate 41. Next, a laminator is used to bond the adhesive sheet side of the sample piece to a resin plate (Bakelite board). A peel test is performed using a tensile tester at 23°C, a peel angle of 180°, and a peel speed of 300 mm / min, in which the backing tape of the sample piece on the resin plate is pulled, and the adhesive strength (peel force) (unit: N / 10 mm) of the test piece to the resin plate at 23°C is measured.

[0130] The thickness of the sensor connecting adhesive layer 42 can be selected as appropriate and is preferably 10 μm to 300 μm. If the thickness of the sensor connecting adhesive layer 42 is 10 μm to 300 μm, the biosensor 1 can be made thinner.

[0131] 5 , the sensor connecting adhesive layer 42 has a third protruding portion 42P. The third protruding portion 42P is a part of the third protruding portion 40P, and may protrude outward from the outer periphery of the sensor connecting adhesive layer 42 in the short side direction beyond the outer periphery of the cover member 11 in the short side direction. By having the sensor connecting adhesive layer 42 have the third protruding portion 42P, it is possible to increase the adhesion area between the second layer member 40 having the sensor connecting adhesive layer 42 and the cover sheet 12, compared to when the sensor connecting adhesive layer 42 is formed to be approximately the same size as the cover member 11.

[0132] (Sensor Support Adhesive Layer) As shown in Figure 3, the sensor support adhesive layer 43 is provided on the surface (lower surface) of the sensor support base material 41 on the attachment side (-Z axis direction), and is a layer that comes into contact with the water absorption layer 50.

[0133] The sensor support adhesive layer 43 preferably has pressure-sensitive adhesive properties, so that the biosensor 1 can be easily attached to the water-absorbing layer 50 by pressing it against the skin 2.

[0134] The sensor supporting adhesive layer 43 can be formed using the same material as the sensor connecting adhesive layer 42, and therefore details thereof will be omitted.

[0135] The material of the sensor supporting adhesive layer 43 is not particularly limited as long as it is a material having pressure-sensitive adhesive properties, and the same material as that of the sensor connecting adhesive layer 42 can be used, so details will be omitted. Like the sensor connecting adhesive layer 42, the sensor supporting adhesive layer 43 may be formed of an adhesive tape made of the above-mentioned material.

[0136] The sensor support adhesive layer 43 is preferably moisture-permeable, allowing water vapor and the like generated from the skin 2 to which the biosensor 1 is attached to escape to the outside from the side surfaces of the sensor support adhesive layer 43. This prevents sweat or water vapor from accumulating at the interface between the sensor support adhesive layer 43 and the water absorption layer 50. As a result, it is possible to prevent a decrease in the adhesive strength of the sensor support adhesive layer 43 due to moisture accumulating at the interface.

[0137] The moisture permeability of the sensor supporting adhesive layer 43 is, for example, 300 g / (m ２・day)~10000g / (m ２ If the moisture permeability of sensor supporting adhesive layer 43 is within the above-mentioned preferred range, even when sensor supporting adhesive layer 43 is attached to water absorption layer 50, sweat generated from skin 2 or water vapor generated by sweat can be transmitted from sensor supporting adhesive layer 43 to the outside.

[0138] The adhesive strength of the sensor supporting adhesive layer 43 may be any strength that allows it to maintain adhesion to the water absorption layer 50, and is preferably, for example, 2.5 N / 10 mm to 5.0 N / 10 mm. If the adhesive strength of the sensor supporting adhesive layer 43 is within the above-mentioned preferred range, the sensor supporting adhesive layer 43 can be maintained in a state where it is stably attached to the water absorption layer 50.

[0139] The moisture permeability and adhesive strength of the sensor supporting adhesive layer 43 may be measured by the same measuring method as that for the sensor connecting adhesive layer 42 .

[0140] The thickness of the sensor supporting adhesive layer 43 can be selected as appropriate and is preferably 10 μm to 300 μm. If the thickness of the sensor supporting adhesive layer 43 is 10 μm to 300 μm, the biosensor 1 can be made thinner.

[0141] 5 , the sensor support adhesive layer 43 has a third protruding portion 43P. The third protruding portion 43P is a part of the third protruding portion 40P, and may protrude outward from the outer periphery of the sensor support adhesive layer 43 in the short side direction beyond the outer periphery of the cover member 11 in the short side direction. By having the sensor support adhesive layer 43 have the third protruding portion 43P, it is possible to increase the adhesion area between the second layer member 40 having the sensor support adhesive layer 43 and the cover sheet 12, compared to when the sensor support adhesive layer 43 is formed to be approximately the same size as the cover member 11.

[0142] [Water-Absorbing Layer] As shown in FIG. 3 , the water-absorbing layer 50 is attached to the underside of the second layer member 40 and the underside of the first cover adhesive layer 122A of the first layer member 10, and has an attachment surface 501 that is the underside that is attached to the skin 2. The periphery of the water-absorbing layer 50 may be attached to the underside of the first cover adhesive layer 122A of the first layer member 10. The periphery may be located at a position corresponding to the second protruding portion 12P of the cover sheet 12 in a bottom view, or may be located at a position corresponding to the second protruding portion 12P and other areas. This may be determined depending on the size of the biosensor 1 and the water-absorbing layer 50, etc. As shown in FIGS. 1 and 2 , the outer shape of the water-absorbing layer 50 may be substantially the same as the outer shape of the second layer member 40. It is preferable that the water-absorbing layer 50 be formed so that the outer shape of the water-absorbing layer 50 is substantially the same as the outer shape of the second layer member 40 when attached to the underside of the first cover adhesive layer 122A. Furthermore, the water absorption layer 50 may have the first cover adhesive layer 122A attached to an area other than the area to which the second layer member 40 is attached in a plan view.

[0143] 3 , the water-absorbing layer 50 has an exposure opening 50a at a position corresponding to the electrode 20, which exposes the electrode 20 to the attachment surface 501. By exposing the electrode 20 to the attachment surface 501 through the exposure opening 50a, the water-absorbing layer 50 can bring the electrode 20 into contact with the surface of the skin 2.

[0144] 6, the exposure opening 50a has a size and is formed so as not to come into contact with the electrode 20 when the water absorption layer 50 is attached to the lower surfaces of the first layer member 10 and the second layer member 40 in a bottom view. Since only a portion of the electrode 20 is exposed to the water absorption layer 50 side by the second layer member 40 in a bottom view, the exposure opening 50a only needs to be formed so that the electrode 20 exposed from the second layer member 40 does not come into contact with the inner wall of the exposure opening 50a in a bottom view, creating a gap.

[0145] The water absorption layer 50 preferably has a lower tensile strength than the cover member 11 and the cover adhesive layer 122 of the cover sheet 12. That is, the water absorption layer 50 preferably has higher elasticity than the cover member 11 and the cover base material 121. If the water absorption layer 50 has a lower tensile strength than the cover member 11 and the cover base material 121, it is more likely to deform in response to deformation of the skin 2, thereby preventing pain, itchiness, and the like from occurring on the skin 2.

[0146] The moisture permeability of the water absorption layer 50 is not particularly limited and can be set appropriately. For example, ２ ·day) or more, and ２ ·day) or more, and 3000 g / (m ２ It is more preferable that the moisture permeability of the water absorption layer 50 is 1000 g / (m ２ The upper limit of the moisture permeability in the thickness direction of the water absorption layer 50 is not particularly limited, but from the viewpoint of the strength and shape retention of the water absorption layer 50, it is set to 8000 g / (m ２ ・day) or less is sufficient.

[0147] The method for measuring the moisture permeability of the water absorption layer 50 is not particularly limited, and a general method can be used, and the same measuring method as the method for measuring the moisture permeability of the cover member 11 may be used.

[0148] The water absorption layer 50 may be an adhesive layer formed including a porous body having a porous structure.

[0149] The water-absorbing layer 50 has an attachment base material 51 and an attachment adhesive layer 52 provided on the lower surface of the attachment base material 51. At least one of the attachment base material 51 and the attachment adhesive layer 52 of the water-absorbing layer 50 may be formed of a porous material. The water-absorbing layer 50 may further have an attachment adhesive layer on the upper surface of the attachment base material.

[0150] When the water absorption layer 50 is composed of an attachment base material 51 and an attachment adhesive layer 52 , the exposed opening 50 a of the water absorption layer 50 is composed of an exposed opening 51 a of the attachment base material 51 and an exposed opening 52 a of the attachment adhesive layer 52 .

[0151] (Attachment Base Material) The attachment base material 51 has flexibility, waterproofness, and moisture permeability. Like the cover base material 121, the attachment base material 51 may be a non-porous material or a porous material as long as it has flexibility, waterproofness, and moisture permeability.

[0152] The porous body can be the same as the porous body used in the cover substrate 121, and may have a cell structure such as open cells, closed cells, or semi-closed cells. That is, the porous body may be a porous body having an open cell structure, a porous body having a closed cell structure, or a porous body having a semi-closed cell structure. Among these, a porous body having a closed cell structure is preferred because it exhibits higher moisture permeability. Examples of the porous body that can be used include a foam sheet and a nonwoven fabric sheet.

[0153] The material for forming the attachment substrate 51 may be, for example, a thermoplastic resin such as a polyurethane resin, a polystyrene resin, a polyolefin resin, a silicone resin, an acrylic resin, a vinyl chloride resin, or a polyester resin, or a flexible material such as a thermoplastic elastomer. The thermoplastic elastomer may be the same as that used for the cover substrate 121.

[0154] (Attachment Adhesive Layer) The attachment adhesive layer 52 can be formed using a pressure-sensitive adhesive material, similar to the first cover adhesive layer 122 A. Examples of pressure-sensitive adhesive materials that can be used include acrylic adhesives and silicone adhesives, and it is preferable to use an acrylic adhesive.

[0155] The adhesive layer 52 for application may be an adhesive tape made of the above-mentioned material.

[0156] The adhesive layer 52 may be formed of a porous material. An example of the configuration of the adhesive layer 52 formed of a porous material is shown in FIG. 7 . As shown in FIG. 7 , the adhesive layer 52 may have an adhesive portion 521 having adhesiveness and a non-adhesive ventilation portion 522 on the attachment surface 501. The adhesive portion 521 is a region where the adhesive forming the water-absorbing layer 50 is present. The ventilation portion 522 is a region where the adhesive forming the water-absorbing layer 50 is absent or where the adhesive is present in less amount than the adhesive portion 521 and does not exhibit adhesiveness. The moisture permeability of the water-absorbing layer 50 tends to increase as the adhesive is thinner. Therefore, the water-absorbing layer 50 has both portions where the adhesive is present and portions where the adhesive is not present in the planar direction (XY direction) of the attachment surface 501. This allows the adhesive portion 521 to maintain its adhesive strength while the ventilation portion 522 exhibits moisture permeability.

[0157] The adhesive portions 521 and the ventilation portions 522 may be arranged alternately. Since there are both areas where the adhesive is present and areas where the adhesive is not present, the adhesive can be scattered on the surface of the water absorption layer 50. By providing the water absorption layer 50 with the adhesive portions 521 and the ventilation portions 522 arranged alternately, it is possible to improve moisture permeability while maintaining adhesive strength.

[0158] The cross section of the ventilation portion 522 in the width direction may be formed into a generally concave or V-shape, etc., and the ventilation portion 522 may be formed into a generally concave or V-shape, etc. when viewed along its extension direction, i.e., in a cross section perpendicular to the extension direction of the ventilation portion 522. Note that the extension direction is the left-right direction in Figure 7.

[0159] The adhesive portion 521 is a region where an adhesive that forms the water absorption layer 50 is present. The adhesive portion 521 is a region formed in a substantially convex shape in a cross-sectional view of the adhesive layer 52 for application.

[0160] The ventilation section 522 is a region where there is no adhesive or where the height is lower than the adhesive section 521. The ventilation section 522 is a region where the surface of the adhesive layer 52 for application is penetrated and the application base material 51 is exposed, or a region formed in a substantially concave shape in a cross-sectional view of the adhesive layer 52 for application.

[0161] 7, the ventilation sections 522 may be arranged in a wave pattern at substantially equal intervals in a bottom view. The ventilation sections 522 may be arranged linearly along the short-side or long-side direction of the water absorption layer 50 in a plan view, or may be arranged in a lattice pattern along the long-side and short-side directions of the water absorption layer 50.

[0162] The width of ventilation section 522 is not particularly limited and may be any appropriate size. The width of ventilation section 522 should be sufficient to ensure the space necessary for sweat generated from skin 2 or water vapor generated by sweat to pass through, provide breathability, and exhibit moisture permeability. In addition, it should be sufficient to prevent a decrease in the adhesive strength of water-absorbing layer 50 and a decrease in the adhesiveness necessary for attachment to skin 2.

[0163] The water-absorbing layer 50 may be formed of an adhesive tape as long as it has a porous body. The adhesive tape may be a single-sided adhesive tape having adhesive properties on one side or a double-sided adhesive tape having adhesive properties on both sides. The water-absorbing layer 50 may be formed of, for example, an adhesive nonwoven tape.

[0164] The thickness of the water-absorbing layer 50 can be set as appropriate and is preferably 50 μm to 500 μm, for example. The thickness of the water-absorbing layer 50 is more preferably 100 μm or more, and even more preferably 150 μm or more. The thickness of the water-absorbing layer 50 is more preferably 450 μm or less, and even more preferably 400 μm or less. If the thickness of the water-absorbing layer 50 is within the above-mentioned preferred range, it can exhibit adhesion to the skin 2 and waterproof properties.

[0165] As shown in FIG. 3 , the water-absorbing layer 50 has a first protruding portion 50P. The first protruding portion 50P may be composed of a first protruding portion 51P of the attachment base material 51 and a first protruding portion 52P of the attachment adhesive layer 52. In plan view, the first protruding portion 50P is larger than the second protruding portion 12P of the cover sheet 12 and protrudes outward from the outer periphery of the cover sheet 12. Because the first protruding portion 50P protrudes further outward from the outer periphery of the cover sheet 12 in plan view, similar to the cover sheet 12, the area of ​​adhesion to the skin 2 can be increased compared to when the water-absorbing layer 50 is formed to the same size as the cover member 11. This improves the adhesion of the biosensor 1 to the skin 2. Furthermore, the adhesive strength of the water-absorbing layer 50 may be weaker than when the water-absorbing layer 50 is formed to the same size as the cover member 11. By reducing the adhesive force per unit area of ​​the water absorption layer 50, the biosensor 1 can be easily peeled off from the skin 2 without reducing the adhesive performance of the biosensor 1 to the skin 2. Therefore, the biosensor 1 can be peeled off from the skin 2 without causing pain to the subject.

[0166] Furthermore, because first protruding portion 50P is located at a position that protrudes outward from the outer periphery of cover member 11, when skin 2 deforms, the edge of the outer periphery of cover member 11 can be prevented from hitting water-absorbing layer 50 and coming into direct contact with skin 2. Furthermore, by preventing irritation to skin 2 from the outer periphery of cover member 11, the occurrence of pain or itching on skin 2 can be reduced. Therefore, the wearing comfort of biosensor 1 to the subject can be improved when it is attached to skin 2.

[0167] Furthermore, when the skin 2 stretches due to body movement, the first protruding portions 50P function as a buffer material that absorbs the stretch of the skin 2, and can absorb a portion of the stretch of the skin 2, thereby reducing stretching of the outer peripheries of the cover member 11 and the cover sheet 12. In other words, when the skin 2 stretches due to body movement, the first protruding portions 50P located on the outer periphery of the water-absorbing layer 50 stretch in response to the stretch of the skin 2, thereby reducing the stress applied to the cover member 11 and the cover sheet 12, and therefore reducing stretching of the outer peripheries of the cover member 11 and the cover sheet 12.

[0168] In this embodiment, the first protruding portion 50P protrudes from the entire outer periphery of the cover sheet 12, but only a portion of the first protruding portion 50P may protrude from the outer periphery of the cover sheet 12. In other words, the first protruding portion 50P may be provided only in a position of the biosensor 1 that is likely to peel off from the skin 2 due to body movement or the like.

[0169] For example, when the biosensor 1 is attached to the subject P (see FIG. 8) so that the flat portion 112A of the cover member 11 is positioned on the ventral side of the subject P (see FIG. 8), the ventral position is more likely to be displaced by body movement than the flat portion 112B side, and the biosensor 1 is more likely to peel off than the flat portion 112B side. For this reason, it is preferable to provide the first protruding portion 50P at least on the end of the cover member 11 on the flat portion 112A side.

[0170] Furthermore, the longitudinal (Y-axis) ends of the biosensor 1 are more likely to be displaced by body movement than the width (X-axis) ends, and are therefore more likely to peel off. For this reason, it is preferable to provide the first protrusions 50P only at both longitudinal (Y-axis) ends of the biosensor 1.

[0171] The protrusion length of first protrusion portion 50P is preferably 20 mm or less, more preferably 15 mm or less, and even more preferably 10 mm or less, of the outer shape of cover member 11. If the protrusion length of first protrusion portion 50P is 20 mm or less of the outer shape of cover member 11, first protrusion portion 50P can have a sufficient area to allow sweat and the like generated on skin 2 to be released to the outside.

[0172] 1 and 2 , when the biosensor 1 is not in use, it is preferable to attach a release liner 60 to the adhesive surfaces of the electrodes 20 and the water-absorbing layer 50 that are in contact with the skin 2 in order to protect the electrodes 20 and the water-absorbing layer 50 until use. When in use, the release liner 60 is peeled off from the electrodes 20 and the water-absorbing layer 50, and the adhesive surface of the biosensor 1 can be attached to the skin 2. By leaving the release liner 60 attached to the adhesive surface, the adhesive strength of the electrodes 20 and the water-absorbing layer 50 can be maintained even when the biosensor 1 is stored for a long period of time. Therefore, by peeling the release liner 60 from the electrodes 20 and the water-absorbing layer 50 when in use, the adhesive surface can be securely attached to the skin 2 for use.

[0173] The method for manufacturing the biosensor 1 is not particularly limited, and any appropriate method can be used for manufacturing the biosensor 1. An example of the method for manufacturing the biosensor 1 will be described below.

[0174] 1 and 2, a first layer member 10, an electrode 20, a sensor unit 30, a second layer member 40, and a water absorption layer 50 are prepared. The first layer member 10, the electrode 20, the sensor unit 30, the second layer member 40, and the water absorption layer 50 can be manufactured by any suitable manufacturing method without any particular limitation, as long as the method can be used to manufacture each of them.

[0175] After preparing the first layer member 10, electrodes 20, sensor unit 30, second layer member 40, and water absorption layer 50 that constitute the biosensor 1 shown in Fig. 1, the sensor unit 30 is placed on the second layer member 40. Then, the first layer member 10, electrodes 20, sensor unit 30, and second layer member 40 are stacked in this order from the first layer member 10 side toward the second layer member 40 side to create a laminate. Then, the underside of the laminate facing the second layer member 40 is placed on the water absorption layer 50. This completes the biosensor 1 shown in Fig. 1.

[0176] 8 is an explanatory diagram showing the biosensor 1 of FIG. 1 attached to the chest of a subject P. As shown in FIG. 8, for example, the biosensor 1 is attached to the skin of the subject P with its longitudinal direction (Y-axis direction) aligned with the sternum of the subject P, one electrode 20 on the upper side, and the other electrode 20 on the lower side. The biosensor 1 is attached to the skin of the subject P via the water-absorbing layer 50, and the electrodes 20 are pressed against the skin of the subject P, and the biosensor 1 acquires biosignals such as electrocardiogram signals from the subject P via the electrodes 20. The biosensor 1 stores the acquired biosignal data in a non-volatile memory such as a flash memory mounted on the component mounting section 321.

[0177] Thus, the biosensor 1 includes a first layer member 10, a sensor unit 30, a second layer member 40, and a water-absorbing layer 50. The first layer member 10 includes a cover member 11 and a cover substrate 121, and the second layer member 40 includes a sensor support substrate 41. The water-absorbing layer 50 is formed of a porous material and is therefore breathable. Furthermore, the water-absorbing layer 50 has a first protruding portion 50P, which allows for a large contact area with the outside. Therefore, the biosensor 1 can easily release moisture, such as sweat, generated from the skin 2 through the water-absorbing layer 50 and to the outside through the first protruding portion 50P. Furthermore, the biosensor 1 can prevent sweat and other moisture generated from the skin 2 from accumulating between the attachment surface 501 of the water-absorbing layer 50 and the skin 2, thereby reducing the likelihood of itching in the subject. The water-absorbing layer 50 has the first protruding portion 50P, which allows the outer periphery of the water-absorbing layer 50 to be larger than the outer peripheries of the first layer member 10 and the second layer member 40 in a planar view, and allows the outer shape of the water-absorbing layer 50 in a planar view to be larger than the outer shapes of the cover member 11 and the cover substrate 121 in a planar view. This allows the water-absorbing layer 50 to have a larger adhesion area with respect to the skin 2, making it easier to maintain its adhesion to the skin 2. Therefore, the biosensor 1 can reduce discomfort to the subject and maintain its adhesion to the skin 2.

[0178] Furthermore, by providing the first protruding portion 50P in the water-absorbing layer 50, the area of ​​adhesion between the water-absorbing layer 50 and the skin 2 is increased compared to when the water-absorbing layer 50 is formed to be approximately the same size as the cover member 11, and this prevents the water-absorbing layer 50 from peeling off from the skin 2. This allows the water-absorbing layer 50 to be stably attached to the skin 2 for a longer period of time, thereby extending the measurement time for bioinformation.

[0179] Furthermore, by providing the first protruding portion 50P in the water-absorbing layer 50, the biosensor 1 can, similarly to the second protruding portion 12P, prevent the outer peripheral edge of the cover member 11 from coming into direct contact with the skin 2 when the skin 2 is deformed due to body movement, thereby reducing irritation to the skin 2 caused by contact with the outer peripheral of the cover member 11.

[0180] Furthermore, by providing the first protruding portion 50P in the water-absorbing layer 50, the contact area of ​​the water-absorbing layer 50 with the skin 2 can be increased, so that even if the adhesive strength of the water-absorbing layer 50 is weakened, the water-absorbing layer 50 can be easily attached to the skin 2, and after use, it can be easily peeled off from the skin 2 without causing pain to the subject.

[0181] Furthermore, by providing the second layer member 40 to the biosensor 1, even if sweat or the like from the skin 2 passes through the water-absorbing layer 50 and reaches the second layer member 40, the second layer member 40 can prevent the sweat or the like from entering the storage space S, thereby preventing condensation or the like from occurring in the sensor unit 30.

[0182] In the biosensor 1, the protruding length of the first protruding portion 50P can be set to 20 mm or less, which is the outer shape of the cover member 11. This allows the biosensor 1 to more reliably release moisture such as sweat generated from the skin 2 to the outside through the first protruding portion 50P, thereby more reliably preventing sweat generated from the skin 2 from accumulating between the attachment surface 501 and the skin 2. Therefore, the biosensor 1 can more reliably reduce discomfort such as itching in the subject, and also suppress a decrease in the adhesive strength of the water-absorbing layer 50, making it easier to maintain adhesion to the skin 2.

[0183] The biosensor 1 can be provided with a second protrusion 121P on the cover substrate 121. A cover adhesive layer 122 corresponding to the shape of the cover substrate 121 is provided on the water absorption layer 50 side of the cover substrate 121, and the second protrusion 121P and the second protrusion 122P of the cover adhesive layer 122 form a second protrusion 12P of the cover sheet 12. By providing the second protrusion 12P, the cover sheet 12 can have at least a portion of its outer periphery sized between the outer periphery of the cover member 11 and the outer periphery of the water absorption layer 50 in a plan view. Therefore, the biosensor 1 can have a stepped structure in which the outer dimensions of the cover member 11, cover sheet 12, and water absorption layer 50 increase in order from the cover member 11 side toward the water absorption layer 50 side. The biosensor 1 can increase the contact area between the cover sheet 12 and the water-absorbing layer 50, making it difficult for the cover sheet 12 to peel off from the water-absorbing layer 50 and preventing delamination between the cover sheet 12 and the water-absorbing layer 50. As a result, the biosensor 1 can easily maintain the airtightness of the storage space S and prevent water from seeping in between the layers, thereby preventing the sensor unit 30 from coming into contact with water or other moisture. Therefore, the biosensor 1 can exhibit waterproofing while improving adhesion to the skin 2.

[0184] Furthermore, the biosensor 1 is provided with a second protruding portion 12P on the cover sheet 12, which reduces the occurrence of delamination between the cover sheet 12 and the water-absorbing layer 50. This prevents the electrodes 20 from coming into contact with the water-absorbing layer 50 due to separation between the cover sheet 12 and the water-absorbing layer 50 during measurement of biological information, thereby preventing large noise from being generated. This allows the biosensor 1 to improve the detection accuracy of biological signals.

[0185] Furthermore, by providing second protrusion 12P on cover sheet 12, biosensor 1 can prevent the outer peripheral edge of cover member 11 from directly contacting skin 2 when skin 2 deforms due to body movement, thereby reducing irritation to skin 2 caused by contact with the outer periphery of cover member 11. In particular, when cover substrate 121 has high flexibility, deformation of skin 2 makes it easier for the edge of the outer periphery of cover member 11 to face skin 2. Even in such cases, biosensor 1 can reduce the pressing force on skin 2 by the outer periphery of cover member 11 with second protrusion 12P, thereby reducing irritation to skin 2.

[0186] In the biosensor 1, the protrusion length of the second protrusion portion 121P of the cover substrate 121 can be 10 mm or less of the outer shape of the cover member 11. As described above, the second protrusion portion 121P and the second protrusion portion 122P of the cover adhesive layer 122 provided on the water absorption layer 50 side of the cover substrate 121 constitute the second protrusion portion 12P of the cover sheet 12. Therefore, the protrusion length of the second protrusion portion 12P of the cover sheet 12 can be 10 mm or less of the outer shape of the cover member 11, similar to the cover substrate 121. In the biosensor 1, a stepped structure can be more reliably formed in which the outer shapes of the cover member 11, cover sheet 12, and water absorption layer 50 increase in order from the cover member 11 side toward the water absorption layer 50 side, and a contact area of ​​the cover sheet 12 with the water absorption layer 50 can be ensured. This makes it difficult for delamination to occur between the cover sheet 12 and the water-absorbing layer 50 in the biosensor 1, thereby preventing water from seeping in between the layers and ensuring waterproofing.

[0187] The biosensor 1 can be provided with a third protruding portion 41P on the sensor support substrate 41. A sensor connecting adhesive layer 42 corresponding to the shape of the sensor support substrate 41 is provided on the first layer member 10 side of the sensor support substrate 41, and a sensor supporting adhesive layer 43 corresponding to the shape of the sensor support substrate 41 is provided on the water absorption layer 50 side of the sensor support substrate 41. The third protruding portion 41P, the third protruding portion 42P of the sensor connecting adhesive layer 42, and the third protruding portion 43P of the sensor supporting adhesive layer 43 form a third protruding portion 40P of the second layer member 40. Because the third protruding portion 40P is provided at a position sandwiched between the first layer member 10 and the water absorption layer 50, external exposure of the third protruding portion 40P is prevented, and interlayer delamination between the second layer member 40 and the first layer member 10 and between the second layer member 40 and the water absorption layer 50 can be prevented. Therefore, the biosensor 1 can easily maintain the airtightness of the storage space S and can prevent water from seeping in between the layers, thereby preventing the sensor unit 30 from coming into contact with water or other moisture. Therefore, the biosensor 1 can have improved waterproofing.

[0188] In the biosensor 1, the protrusion length of the third protrusion portion 41P of the sensor support substrate 41 can be set to 10 mm or less of the outer shape of the cover member 11. As described above, the third protrusion portion 40P of the second layer member 40 is composed of the third protrusion portion 41P, the third protrusion portion 42P, and the third protrusion portion 43P. Therefore, the protrusion length of the third protrusion portion 40P of the cover sheet 12 can be set to 10 mm or less of the outer shape of the cover member 11 in the width direction. As a result, the third protrusion portion 43P prevents the adhesion area of ​​the second protrusion portion 12P of the cover sheet 12 with the water absorption layer 50 from becoming narrower, thereby preventing delamination between the first layer member 10 and the water absorption layer 50 while maintaining the second layer member 40 sandwiched between the first layer member 10 and the water absorption layer 50. Therefore, the biosensor 1 is able to prevent delamination from occurring between the cover sheet 12 sandwiched between the second layer member 40 and the water-absorbing layer 50, thereby preventing water from seeping in between the layers and ensuring waterproofing.

[0189] The biosensor 1 has an electrode 20 provided on the surface of the first layer member 10 facing the water-absorbing layer 50 so as to be connected to the sensor body 32, and an exposed opening 50a can be provided in the water-absorbing layer 50. This allows the electrode 20 of the biosensor 1 to be exposed on the attachment surface 501 of the water-absorbing layer 50 through the exposed opening 50a of the water-absorbing layer 50. Because the electrode 20 of the biosensor 1 can be brought into contact with the surface of the skin 2 through the exposed opening 50a of the water-absorbing layer 50, the biosensor 1 can detect a biosignal using the electrode 20 while the biosensor 1 is attached to the skin 2. Therefore, during use, the biosensor 1 can measure the biosignal by sending the detected biosignal via the electrode 20 to the sensor body 32.

[0190] In the biosensor 1, the cover substrate 121 has a through-hole 121a on the surface facing the cover member 11. The cover substrate 121 and cover adhesive layers 122, which have a shape corresponding to the cover substrate 121 on both the top and bottom surfaces of the cover substrate 121, form a cover sheet 12, which has a through-hole 12a on the surface facing the cover member 11. The cover member 11 and the cover sheet 12 form a storage space S within the first layer member 10. This allows the biosensor 1 to house the sensor unit 30 therein, thereby reducing the thickness of the biosensor 1.

[0191] The cover substrate 121 of the biosensor 1 can be formed using a polyurethane-based thermoplastic elastomer. By forming the cover substrate 121 from a polyurethane-based thermoplastic elastomer, the moisture permeability can be increased by adjusting the thickness of the cover substrate 121 to a desired thickness. This prevents the sensor unit 30 from coming into contact with water, thereby improving the waterproofing of the biosensor 1. Furthermore, adjusting the thickness of the cover substrate 121 to a desired thickness makes it easier to control the adhesive strength to the skin 2. Therefore, the biosensor 1 can prevent peeling between the cover member 11 and the cover substrate 121, thereby improving waterproofing and making it easier to maintain stable adhesion to the skin 2 even when the surface of the skin 2 deforms due to body movement.

[0192] The biosensor 1 can have an adhesive layer 52 on the surface of the water-absorbing layer 50 that faces the skin 2. This allows the adhesive surface 501 of the biosensor 1 to be firmly attached to the skin 2, thereby improving the adhesion of the biosensor to the skin 2.

[0193] The biosensor 1 can include a cover adhesive layer 122 on both the opening side and the water-absorbing layer 50 side of the cover substrate 121. Because the cover adhesive layer 122 is adhesive, the biosensor 1 can bring the electrodes 20 into contact with the surface of the skin 2 while they are stably attached to the first layer member 10 by the cover adhesive layer 122. Therefore, even if the surface of the skin 2 deforms, the biosensor 1 can prevent the electrodes 20 from shifting in position and reduce noise, thereby improving the detection accuracy of biosignals. Furthermore, because the cover member 11 and the cover substrate 121 can be bonded together via the cover adhesive layer 122, even if the first layer member 10 is composed of multiple separate members, the first layer member 10 can be formed to have a storage space S in which the sensor body 32 is placed by bonding the individual members constituting the first layer member 10 together.

[0194] In the biosensor 1, the cover sheet 12 includes a cover substrate 121 and a cover adhesive layer 122. The cover substrate 121 and the cover adhesive layer 122 have through holes 121a and 122a at positions corresponding to the openings of the cover member 11 when viewed from the bottom of the biosensor 1, and the cover member 11, the cover substrate 121, and the cover adhesive layer 122 form a storage space S. The biosensor 1 can accommodate the sensor main body 32 within the storage space S, preventing contact of the sensor main body 32 with the outside and allowing the biosensor 1 to be compact. Furthermore, the biosensor 1 can bond the cover member 11 and the cover substrate 121 via the cover adhesive layer 122, preventing peeling between the cover member 11 and the cover substrate 121. Therefore, the biosensor 1 can be stably attached to the skin 2 even if the first layer member 10 is composed of multiple separate members.

[0195] The biosensor 1 can include an adhesive layer 52 for attachment of the water-absorbent layer 50, with adhesive portions 521 and ventilation portions 522 arranged alternately. This allows the biosensor 1 to easily allow sweat generated from the skin 2 to enter the gaps between the ventilation portions 522 and the skin 2 over a wide area of ​​the skin 2. This allows the biosensor 1 to release sweat generated from the skin 2 to the outside over a wide area of ​​the skin 2. Furthermore, the biosensor 1 can prevent sweat from accumulating at the interface between the attachment surface 501 of the water-absorbent layer 50 and the skin 2, thereby maintaining the adhesive force of the water-absorbent layer 50 to the skin 2 over a wide area of ​​the skin 2 and making it less likely to peel off from the skin 2. Therefore, the biosensor 1 can increase the moisture permeability in the planar direction while maintaining stable adhesive force over a wider area of ​​the water-absorbent layer 50, allowing for more stable attachment to the skin 2.

[0196] In the biosensor 1, the ventilation portions 522 of the water-absorbent layer 50 can be arranged in a wave-like pattern when viewed from the bottom. This allows water vapor generated by sweat from the skin 2 to easily move in the width direction (short direction) of the water-absorbent layer 50. Water vapor that has moved to the vicinity of both widthwise ends of the water-absorbent layer 50 can pass through both widthwise ends of the water-absorbent layer 50 and escape to the outside. The biosensor 1 can easily allow water vapor generated by sweat from the skin 2 to be more evenly released to the outside from the width direction of the water-absorbent layer 50 through the gap between the water-absorbent layer 50 and the skin 2. Therefore, the biosensor 1 can more effectively prevent sweat from accumulating between the attachment surface 501 of the water-absorbent layer 50 and the skin 2, thereby more stably maintaining the adhesive force of the water-absorbent layer 50 to the skin 2 and making it less likely to peel off from the skin 2. Therefore, the biosensor 1 can be more stably attached to the skin 2.

[0197] In the biosensor 1, the exposed opening 50a of the water-absorbing layer 50 can be provided so that the electrode 20 does not come into contact with the water-absorbing layer 50. Therefore, even if the surface of the skin 2 is deformed due to expansion and contraction of the skin 2 caused by body movement, the biosensor 1 can prevent the electrode 20 from coming into contact with the inner wall of the exposed opening 50a, etc., and can also prevent expansion and contraction of the electrode 20, thereby preventing noise from increasing when measuring biosignals. Therefore, the biosensor 1 can improve the measurement accuracy of biosignals.

[0198] In the biosensor 1, the sensor support substrate 41 can be provided on the underside of the cover substrate 121 so that the electrode 20 is exposed. This allows the electrode 20 to be exposed from the exposure opening 50a and come into contact with the skin 2 without being obstructed, even if the second layer member 40 is provided on the water absorption layer 50 side of the electrode 20.

[0199] As described above, the biosensor 1 can maintain its adherence to the skin 2 during use and can stably measure bioinformation from the skin 2 for a long period of time, and therefore can be effectively used as an adhesive biosensor that is attached to human skin 2, etc. The biosensor 1 can be suitably used, for example, in wearable healthcare devices that are attached to the skin 2, etc. of a subject and require high electrocardiogram detection sensitivity and high suppression of noise generated in the electrocardiogram.

[0200] In this embodiment, as shown in Figure 9, the first cover adhesive layer 122A and the second cover adhesive layer 122B do not have the second protruding portion 122P, and the outer shapes of the first cover adhesive layer 122A and the second cover adhesive layer 122B may be approximately the same as that of the cover member 11 when viewed in a plane.

[0201] Although the embodiments have been described above, they are presented as examples and the present invention is not limited to the above embodiments. The above embodiments can be implemented in various other forms, and various combinations, omissions, substitutions, modifications, etc. can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as set forth in the claims.

[0202] Examples of embodiments of the present invention are as follows: <1> A biosensor to be attached to a living organism, comprising: a sensor main body that acquires bioinformation; a cover member having a recess for accommodating at least a portion of the sensor main body and an opening that forms the recess; a base material provided on the cover member side of the opening; a sensor support base material provided on the side of the sensor main body opposite the cover member side and on which the sensor main body is placed; and a water absorption layer provided on a side of the sensor support base material opposite the cover member side and having an attachment surface to be attached to the living organism, wherein the water absorption layer is made of a porous material, and has a first protrusion portion that protrudes beyond the outer periphery of the cover member, the base material, and the sensor support base material in at least a part of the outer periphery of the water absorption layer in a plan view. <2> The biosensor according to <1>, wherein the protrusion length of the first protrusion portion is 20 mm or less of the outer diameter of the cover member. <3> The biosensor according to <1> or <2>, wherein the substrate has a second protruding portion in at least a part of the outer periphery of the substrate, in a plan view, which is larger than the outer periphery of the cover member and smaller than the outer periphery of the water absorption layer. <4> The biosensor according to <3>, wherein the protruding length of the second protruding portion is 10 mm or less of the outer shape of the cover member. <5> The biosensor according to any one of <1> to <4>, wherein the sensor support substrate has a third protruding portion in at least a part of the outer periphery of the sensor support substrate, in a plan view, which is larger than the outer periphery of the cover member and smaller than the substrate, and the third protruding portion is sandwiched between the substrate and the water absorption layer. <6> The biosensor according to <5>, wherein the protruding length of the third protruding portion is 10 mm or less of the outer shape of the cover member. <7> The biosensor according to any one of <1> to <5>, further comprising an electrode provided on the water absorption layer side of the base material and connected to the sensor body, the water absorption layer having an exposure opening for exposing a portion of the electrode to the attachment surface side. <8> The biosensor according to any one of <1> to <7>, further comprising a through-hole on a surface facing the cover member at a position corresponding to the opening, the cover member and the base material forming a storage space for accommodating the sensor body.<9> The biosensor according to any one of <1> to <8>, wherein the substrate contains a polyurethane-based thermoplastic elastomer. <10> The biosensor according to any one of <1> to <8>, wherein the water absorption layer has an adhesive layer on the surface facing the living body. <11> The biosensor according to any one of <1> to <10>, wherein the substrate has an adhesive covering layer on at least one of the surfaces facing the cover member and the water absorption layer. <12> The biosensor according to <7>, wherein the exposure opening is formed so that the electrode and the water absorption layer do not come into contact with each other. <13> The biosensor according to <7> or <12>, wherein the sensor support substrate is provided so as to expose the electrode on the underside of the substrate.

[0203] This application claims priority based on Japanese Patent Application No. 2023-150820, filed with the Japan Patent Office on September 19, 2023, and incorporates the entire contents of said application by reference.

[0204] REFERENCE SIGNS LIST 1 Biosensor 2 Skin 10 First layer member 11 Cover member 12 Cover sheet 12P, 121P, 122P Second protruding portion 12a, 121a, 122a Through-hole 20, 20A, 20B Electrode 30 Sensor portion 31 Flexible substrate 32 Sensor body 33A, 33B Connection portion 34 Battery 40 Second layer member 41 Sensor support substrate 40P, 41P, 42P, 43P Third protruding portion 42 Sensor connecting adhesive layer 43 Sensor support adhesive layer 44 Groove portion 50 Water absorption layer 50P, 51P, 52P First protruding portion 50a Exposure opening 51 Adhesive substrate 52 Adhesive layer for attachment 111 Protruding portion 111a Recess 112A, 112B Flat portion 121 Cover base material 122 Cover adhesive layer 122A First cover adhesive layer 122B Second cover adhesive layer 321 Component mounting portion 322 Battery mounting portion 331A, 331B Wiring 332A, 332B Terminal portion 501 Attachment surface 521 Adhesive portion 522 Ventilation portion

Claims

1. A biosensor to be affixed to a living organism, comprising: a sensor body for acquiring bioinformation; a cover member having a recess in which at least a portion of the sensor body is accommodated and an opening forming the recess; a base material provided on the opening side of the cover member; a sensor support base material provided on the side opposite the cover member side of the sensor body and on which the sensor body is placed; and a water absorption layer provided on a side of the sensor support base material different from the cover member side and having an attachment surface to be affixed to the living organism, wherein the water absorption layer is made of a porous body and has a first protruding portion that protrudes beyond the outer periphery of the cover member, the base material, and the sensor support base material in at least a part of the outer periphery of the water absorption layer in a plan view.

2. The biosensor according to claim 1, wherein the protruding length of said first protruding portion is 20 mm or less than the outer shape of said cover member.

3. The biosensor according to claim 1, wherein the substrate has, in a plan view, a second protruding portion on at least a portion of the outer periphery of the substrate, the second protruding portion being larger than the outer periphery of the cover member and smaller than the outer periphery of the water absorption layer.

4. The biosensor according to claim 3, wherein the protruding length of said second protruding portion is 10 mm or less of the outer shape of said cover member.

5. The biosensor described in claim 1, wherein the sensor support substrate has, in a plan view, a third protrusion portion on at least a part of the outer periphery of the sensor support substrate, which is larger than the outer periphery of the cover member and smaller than the substrate, and the third protrusion portion is sandwiched between the substrate and the water absorption layer.

6. The biosensor according to claim 5, wherein the protruding length of said third protruding portion is 10 mm or less than the outer shape of said cover member.

7. The biosensor according to claim 1, further comprising an electrode provided on the water-absorbing layer side of the substrate and connected to the sensor body, the water-absorbing layer having an exposure opening for exposing a portion of the electrode to the attachment surface side.

8. The biosensor as described in claim 1, wherein the base material has a through hole on the surface facing the cover member at a position corresponding to the opening, and the cover member and the base material form a storage space for accommodating the sensor body.

9. The biosensor according to claim 1, wherein the substrate comprises a polyurethane-based thermoplastic elastomer.

10. The biosensor according to claim 1, wherein the water-absorbing layer has an adhesive layer on the surface facing the living body.

11. The biosensor according to claim 1, wherein the base material has an adhesive layer for a cover on at least one of the surfaces facing the cover member and the water-absorbing layer.

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