Biosensors

Abstract

To provide a biosensor that can be sealed internally with a simple configuration and is also waterproof. [Solution] The biosensor according to the present invention is a biosensor attached to a living body, comprising: a sensor body for acquiring biological information; a flexible first substrate; a first housing provided on the side of the living body; and a second housing provided on the side opposite to the living body, wherein one or both of the first housing and the second housing have projections that are inserted into through holes in the first substrate, and one or both of the first housing and the second housing have locking portions that engage the projections, and the first substrate is pressed by the first housing and the second housing with the projections engaged with the locking portions.

Description

[Technical Field]

[0001] This invention relates to a biosensor. [Background technology]

[0002] Wearable biosensors are used in medical institutions such as hospitals and clinics, nursing homes, and homes to acquire biological information such as electrocardiogram waveforms, pulse waves, electroencephalograms, and electromyograms. These biosensors are equipped with bioelectrodes that come into contact with the body to acquire the subject's biological information. When measuring biological information, the biosensor is attached to the subject's skin, and the electrical signals related to the biological information are acquired by the bioelectrodes, thereby measuring the biological information.

[0003] As such a biosensor, for example, a physiological monitoring device has been disclosed that has two housings, a flexible body connected to the housings, and two gaskets sandwiched between the housings and the flexible body, and the flexible body is composed of two substrate layers, an electrode sheet placed between the substrate layers, and an electrode attached to the bottom surface of the bottom substrate layer (see, for example, Patent Document 1).

[0004] In physiological monitoring devices, electrodes make equiangled contact with the patient's surface to detect physiological signals from the patient, and electrical signals are transmitted from the electrodes to electronic equipment housed in a housing. A gasket facilitates the attachment of the flexible body to the housing and also provides waterproofing for the housing. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Patent No. 6198849 [Overview of the project] [Problems that the invention aims to solve]

[0006] However, the physiological monitoring device described in Patent Document 1 had the problem that, in addition to the housing and flexible body, it required many components to make up the device, such as providing two gaskets to ensure waterproofing.

[0007] One aspect of the present invention aims to provide a biosensor that can be sealed internally with a simple configuration and is also waterproof. [Means for solving the problem]

[0008] One aspect of the biosensor according to the present invention is: A biosensor that is attached to a living body, The sensor unit that acquires biometric information, A first substrate having flexibility, The first housing provided on the biological side, A second housing is provided on the opposite side of the living organism, Equipped with, One or both of the first housing and the second housing have a projection that is inserted into a through hole in the first substrate, One or both of the first housing and the second housing have a locking portion for engaging the projection, The first substrate is a biosensor that is pressed by the first housing and the second housing while the projection is locked to the locking portion. [Effects of the Invention]

[0009] One embodiment of the biosensor according to the present invention can be sealed internally with a simple configuration and can also be waterproof. [Brief explanation of the drawing]

[0010] [Figure 1] This is a perspective view showing the appearance of a biosensor according to an embodiment of the present invention. [Figure 2] This is a perspective view showing the individual components of a biosensor in a disassembled state. [Figure 3] This is another perspective view showing the individual components of the biosensor in a disassembled state. [Figure 4] It is a sectional view taken along the line I-I of FIG. 1. [Figure 5] It is a sectional view taken along the line II-II of FIG. 1. [Figure 6] It is an explanatory view showing a state where the biosensor of FIG. 1 is attached to the chest of a living body.

Mode for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present invention will be described in detail. For ease of understanding the description, the same reference numerals are given to the same components in each drawing, and duplicate descriptions are omitted. Also, the scales of the members in the drawings may be different from the actual ones. In this specification, "~" indicating a numerical range means including the numerical values described before and after it as the lower limit value and the upper limit value, unless otherwise specified.

[0012] <Biosensor> The biosensor according to this embodiment will be described. Here, the living body refers to a human body (person), as well as animals such as cows, horses, pigs, chickens, dogs, and cats. The biosensor according to this embodiment can be preferably used for living bodies, especially for human bodies. In this embodiment, as an example, the case where the living body is a person will be described.

[0013] The biosensor according to this embodiment is an adhesive type biosensor that is attached to a part of a living body (for example, skin, scalp, forehead, etc.) to measure biological information. In this embodiment, the case where the biosensor is attached to a person's skin and measures an electrical signal (bio-signal) related to the person's biological information will be described. The bio-signal is, for example, an electrical signal representing an electrocardiogram waveform, electroencephalogram, pulse, etc.

[0014] FIG. 1 is a perspective view showing the appearance of the biosensor according to this embodiment, FIG. 2 is a perspective view showing the state where the components of the biosensor are disassembled, FIG. 3 is another perspective view showing the state where the components of the biosensor are disassembled, FIG. 4 is a sectional view in the longitudinal direction of the biosensor, which is the sectional view taken along the line I-I of FIG. 1, and FIG. 5 is a sectional view taken along the line II-II of FIG. 1.

[0015] As shown in Figure 1, the biosensor 1 is a plate-like (sheet-like) member formed in a substantially rectangular shape in plan view, with both ends in the longitudinal direction formed in an arc shape, and the central part in the longitudinal direction being wider in the width direction. As shown in Figures 2 and 3, the biosensor 1 has a first base material 10, an electrode 20, a second layer member 30, a pair of housings 40, and a sensor part 50. As shown in Figure 4, the biosensor 1 is formed by stacking the first base material 10, the electrode 20, and the second layer member 30 in this order and sandwiching them between a pair of housings 40. In the biosensor 1, the electrode 20, the second layer member 30, and one of the housings 40 form the surface that is attached to the skin 2, which is a living organism. The biosensor 1 measures electrical signals (biosignals) related to the subject's biological information by attaching the attachment surface to the skin 2 and measuring the potential difference (polarization voltage) between the skin 2 and the electrode 20.

[0016] In Figures 1 to 5, a three-dimensional Cartesian coordinate system with three axes (X-axis, Y-axis, and Z-axis) is used. The short side of the biosensor is the X-axis, the long side is the Y-axis, and the height direction (thickness direction) is the Z-axis. The side of the biosensor 1 that is attached to the living body (subject) (attachment side) is designated as the +Z-axis direction (outside), and the attachment side is designated 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 up, and the -Z-axis direction as the lower side or down, but this does not represent a universal up-down relationship.

[0017] The inventors of the present invention manufactured a biosensor 1 in which a first base material 10, an electrode 20, and a second layer member 30 are stacked, and a pair of housings 40 are fixed by sandwiching them between the outside of the first base material 10 and the outside of the second layer member 30. The inventors of the present invention realized that by using a flexible base material for the first base material 10, the housings 40 placed on the first base material 10 can bite into and press against the surface of the first base material 10, thereby preventing a gap from forming between one of the housings 40 and the first base material 10. As a result, the inventors of the present invention found that the housing space S formed by the first base material 10, the electrode 20, and the second layer member 30 within the biosensor 1 can be sealed with a simple configuration and exhibit waterproof properties.

[0018] [First base material] As shown in Figures 2 and 3, the first substrate 10 is provided on the side opposite to the skin 2 relative to the electrode 20. The first substrate 10 is formed in a sheet shape. In a plan view of the biosensor 1, the first substrate 10 may be formed so that both ends in the longitudinal direction are arc-shaped, and the central part is wider in the width direction.

[0019] The first base material 10 has an opening 11 at a position facing the pair of housings 40. Preferably, the opening 11 is formed to be larger than or equal to the outer shape of the sensor portion 50 at a position corresponding to the housing 40 in a plan view of the biosensor 1. The opening 11 allows the sensor portion 50 to be housed in the storage space S formed by the recess 42a on the inner surface of the second housing 42, the opening 11, and the second layer member 30 without being obstructed by the first base material 10, and also allows the sensor portion 50 to be connected to the electrode 20.

[0020] The first substrate 10 has a through hole 12 in a plan view of the biosensor 1 at a position corresponding to the projection 412 of the first housing 41. The through hole 12 may be formed to be large enough for the projection 412 of the first housing 41 to pass through.

[0021] The shape of the through-hole 12 is not particularly limited as long as the projection 412 can pass through it, and it may be rectangular, circular, or the like.

[0022] The through-holes 12 are provided in the first substrate 10 in a plan view of the biosensor 1 so as to correspond to the protrusions 412, but the number of through-holes 12 can be three or fewer, or five or more, as long as they are in positions corresponding to the protrusions 412.

[0023] The first base material 10 is held in place by a pair of housings 40, with the projection 412 of the first housing 41 of the pair of housings 40 locked into the locking portion 421 of the second housing 42 of the pair of housings 40, and the second housing 42 pressing against and biting into the surface of the first base material 10.

[0024] The first substrate 10 is a flexible substrate. The first substrate 10 may be formed from a substrate that exhibits flexibility, waterproofing, and breathability, as long as it is flexible. Because the first substrate 10 is flexible, waterproofing, and breathability, it becomes easier to stretch when in contact with the skin 2 and can maintain contact with the skin 2. In addition, water vapor from sweat etc. generated from the skin 2 to which the biosensor 1 is attached can be released to the outside of the biosensor 1 through the first substrate 10. Therefore, the first substrate 10 can easily maintain adhesive durability.

[0025] The moisture permeability of the first substrate 10 is not particularly limited, but is 100 g / (m²). 2 • day) ~ 5000g / (m 2 The moisture permeability of the first substrate 10 may be set to 100 g / (m²). 2 • day) ~ 5000g / (m 2 By doing this (day), the first substrate 10 can allow water vapor that has entered from one side to pass through the first substrate 10 and be stably released from the other side.

[0026] The method for calculating the moisture permeability of the first substrate 10 is not particularly limited and a general method can be used. For example, it can be calculated using the following procedure. (1) Prepare a weighing bottle having an opening with a predetermined area S, and pour enough water into the weighing bottle so that the liquid level is below the opening. (2) Place a part or all of the first substrate 10 as a measurement sample on the entire surface of the opening of the weighing bottle so that no tension is generated on the first substrate 10, fix the measurement sample in the weighing bottle, and seal the weighing bottle. (3) Measure the total mass M1 of the sample, water, and weighing bottle immediately after sealing. (4) Leave the sealed weighing bottle at 40°C and 30% RH for 24 hours. (5) Measure the total mass M2 of the sample, water, and weighing bottle after 24 hours of standing. (6) Calculate the moisture permeability P from the following formula (1). Moisture permeability P=(total mass M1-total mass M2) / predetermined area S...(1)

[0027] The compression ratio of the first substrate 10 is preferably 10% to 40%, more preferably 10% to 30%, and even more preferably 10% to 20%. If the compression ratio of the first substrate 10 is 10% to 40%, warping of the first substrate 10 is suppressed, and the first substrate 10 can be made waterproof.

[0028] The compressibility ratio refers to the percentage of shrinkage when a constant load is applied to the first base material 10. The compressibility ratio of the first base material 10 is the percentage of the difference (T1-T0) between the thickness T1 of the first base material 10 after compression and the thickness T0 of the first base material 10 before compression, as shown in formula (2) below. The compressibility ratio may be measured using a general compressibility measuring device. Compression ratio [%] = {(T1-T0) / T0} × 100 ... (2) (In the formula, T0 represents the thickness of the first substrate 10 before compression, and T1 represents the thickness of the first substrate 10 after compression.)

[0029] The bending rigidity of the first base material 10 is 150 N·mm 2 Preferably, it is 100 N·mm 2 More preferably, the following is true: 30 N·mm 2 It is even more preferable that the bending rigidity of the first base material 10 is 150 N·mm 2 The first substrate 10 can be guaranteed to have sufficient flexibility if the following conditions are met.

[0030] The bending stiffness of the first base material 10 can be determined by performing a three-point bending test in accordance with JIS K 7074 to calculate the bending modulus of the first base material 10, and then multiplying the calculated bending modulus by the second moment of area of ​​the first base material 10.

[0031] Specifically, a test piece is prepared by setting the first substrate 10 to a predetermined size (for example, length 150 mm × width 50 mm × thickness 1 mm). A three-point bending test is performed using the test piece, and the flexural modulus of the test piece is calculated from the initial gradient of the linear portion of the flexural deflection amount-flexural load curve obtained when the flexural deflection amount (unit: mm) is set as the X-axis and the flexural load (unit: N) is set as the Y-axis, according to the following formula (3). The initial gradient is obtained by dividing the change amount ΔF of the flexural load by the change amount Δs of the flexural deflection (ΔF / Δs). When performing the three-point bending test using the test piece, the distance between the two fulcrums for installing the test piece and the descending (compression) speed of the indenter can be appropriately selected according to the size of the test piece, etc. For example, when the size of the test piece is length 150 mm × width 50 mm × thickness 1 mm, the distance between the fulcrums may be 40 mm and the compression speed may be 5 mm / min. E = L 3 / (4bh 3 )×(ΔF / Δs) ···(3) (In formula (3), E is the flexural modulus, L is the distance between the fulcrums, b is the width (50 mm) of the test piece of the first substrate 10, and h is the thickness of the test piece of the first substrate 10.)

[0032] Also, the second moment of area of the test piece is obtained from the following formula (4). I = bh 3 / 12 ···(4) (In the formula, I is the second moment of area, b is the width (50 mm) of the test piece of the first substrate 10, and h is the thickness of the test piece of the first substrate 10.)

[0033] Next, the flexural rigidity of the first substrate 10 is calculated by multiplying the calculated flexural modulus by the second moment of area of the test piece according to the following formula (5). Flexural rigidity = E × I ···(5) (In the formula, E is the flexural modulus of the test piece of the first substrate 10, and I is the second moment of area of the test piece of the first substrate 10.)

[0034] When preparing a plurality of test pieces, the flexural rigidity of the first substrate 10 may be the average value of the flexural rigidities of the plurality of test pieces.

[0035] The first base material 10 is preferably a base material that is flexible and can exhibit pliability, waterproofing, and moisture permeability. The first base material 10 may be formed from a base material that does not have a porous structure, or from a base material that has a porous structure.

[0036] As materials for forming a substrate that does not have a porous structure, thermoplastic resins such as polyurethane resins, polystyrene resins, polyolefin resins, silicone resins, acrylic resins, vinyl chloride resins, and polyester resins can be used. When the first substrate 10 is formed from a substrate that does not have a porous structure, the first substrate 10 may be, for example, a polyurethane sheet such as Esmer URS manufactured by Nippon Matai.

[0037] The substrate having a porous structure may be formed using a porous material that is flexible, waterproof, and breathable. As the porous material, for example, a foamed material (foam) having a cellular structure such as open-cell, closed-cell, or semi-closed-cell can be used. This allows water vapor from sweat etc. generated from the skin 2 to which the biosensor 1 is attached to be released to the outside of the biosensor 1 via the first substrate 10.

[0038] As the material for forming the porous body, thermoplastic resins such as polyurethane resins, polystyrene resins, polyolefin resins, silicone resins, acrylic resins, vinyl chloride resins, and polyester resins can be used, as described above. When the first base material 10 is formed from a porous body, for example, FOLEC manufactured by Inoac Corporation may be used as the first base material 10.

[0039] The thickness of the first base material 10 can be set as appropriate, for example, preferably 0.5 mm to 1.5 mm, more preferably 0.55 mm to 1.0 mm, and even more preferably 0.60 mm to 0.9 mm. If the thickness of the first base material 10 is 0.5 mm to 1.5 mm, the first base material 10 can suppress the intrusion of moisture from the outside, ensure waterproofness, and also have flexibility and breathability, which is preferable.

[0040] In this specification, the thickness of the first substrate 10 refers to the length perpendicular to the main surface of the first substrate 10. The thickness of the first substrate 10 may be, for example, the thickness measured at any point in the cross-section of the first substrate 10, or it may be the average value of measurements taken at several points in any location. Hereafter, the definition of thickness will be the same for other components.

[0041] [electrode] As shown in Figure 4, the electrode 20 is provided on the lower surface 101 of the first substrate 10, which is the attachment side (-Z axis direction), and on the skin 2 side of the sensor portion 50. The electrode 20 is sandwiched between the first substrate 10 and the second layer member 30, with a terminal (not shown) of the sensor portion 50 in contact with a part of the electrode 20 on the sensor portion 50 side. The electrode 20 contacts the skin 2 at the exposed portion 30a of the second layer member 30. When the biosensor 1 is attached to the skin 2, the electrode 20 comes into contact with the skin 2, allowing for the detection of a biological signal. Alternatively, the electrode 20 may be embedded in the second substrate 31 in a state where it is exposed and can contact the skin 2.

[0042] The electrode 20 consists of a pair of electrodes 20A and 20B. As shown in Figures 2 and 3, electrode 20A is positioned on the left side in the figures, and electrode 20B is positioned on the right side in the figures. One end (inside) of electrode 20A in its longitudinal direction (Y-axis direction) is in contact with a terminal (not shown) of the sensor unit 50, and one end (inside) of electrode 20B in its longitudinal direction (Y-axis direction) is in contact with a terminal (not shown) of the sensor unit 50. The pair of electrodes 20A and 20B may have substantially the same shape.

[0043] Furthermore, one end of electrode 20A that contacts a terminal (not shown) of sensor unit 50 is designated as opposing portion 201A, and one end of electrode 20B that contacts a terminal (not shown) of sensor unit 50 is designated as opposing portion 201B. On electrode 20A, the side of the exposed portion 30a of the second layer member 30 is designated as exposed portion 202A, and on electrode 20B, the side of the exposed portion 30a of the second layer member 30 is designated as exposed portion 202B.

[0044] The electrode 20 may have any shape, such as a sheet.

[0045] The shape of electrode 20 in plan view is not particularly limited and may be designed to any shape as appropriate depending on the application. As shown in Figures 2 and 3, electrodes 20A and 20B may have rod-shaped opposing portions 201A and 201B at one end (inside) and circular exposed portions 202A and 202B at the other end (outside) in plan view of the biosensor 1. The connecting portions 203A and 203B between opposing portions 201A and 201B and exposed portions 202A and 202B may be formed in a substantially trapezoidal shape that narrows in diameter from the opposing portion 201A and 201B side to the exposed portion 202A and 202B side.

[0046] The shape and size of the exposed portions 202A and 202B are not particularly limited as long as they do not fall into the exposed portion 30a of the second layer member 30. It is preferable that the exposed portions 202A and 202B are formed to be larger than the exposed portion 30a of the second layer member 30 in a plan view of the biosensor 1. If the shape of the exposed portions 202A and 202B in a plan view is larger than the exposed portion 30a of the second layer member 30, it is possible to prevent the exposed portions 202A and 202B from falling into the exposed portion 30a. Since the exposed portions 202A and 202B are formed to be substantially circular, it is sufficient that the diameter of the exposed portions 202A and 202B is larger than the diameter of the exposed portion 30a. It is preferable that the exposed portions 202A and 202B are formed to be large enough that their outer circumferences remain sandwiched between the first base material 10 and the second layer member 30.

[0047] 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, etc. In particular, from the viewpoint of biosafety, 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 a conductive composition.

[0048] 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 their derivatives, as well as composites thereof. Among these, a composite obtained by doping polyaniline as a dopant to polythiophene is preferred. Among the composites of polythiophene and polyaniline, it is more preferable to use PEDOT / PSS, which is obtained by doping poly(3,4-ethylenedioxythiophene) (also called PEDOT) as the polythiophene and polystyrene sulfonic acid (poly4-styrene sulfonate; PSS) as the polyaniline, because it has a lower contact impedance with living organisms and higher conductivity.

[0049] The binder resin can be a water-soluble polymer or a water-insoluble polymer. As a water-soluble polymer, hydroxyl group-containing polymers such as polyvinyl alcohol (PVA) and modified PVA can be used.

[0050] The conductive composition may contain various common additives such as crosslinking agents and plasticizers in appropriate proportions. Examples of crosslinking agents include aldehyde compounds such as sodium glyoxylate. Examples of plasticizers include glycerin, ethylene glycol, and propylene glycol.

[0051] Common metals and alloys such as Au, Pt, Ag, Cu, and Al can be used as metals and alloys.

[0052] Alternatively, the electrode 20 may be an adhesive electrode formed in a sheet shape (adhesive electrode). If the electrode 20 is adhesive, it is attached to the lower surface 101 of the first substrate 10. The adhesive electrode may be formed using a conductive composition containing a conductive polymer, an aqueous emulsion adhesive, a humectant, and a neutralizing agent.

[0053] The conductive polymer contained in the adhesive electrode is the same as described above, so details are omitted.

[0054] The water-based emulsion adhesive contained in the adhesive electrode is used as a binder resin for the adhesive electrode. The water-based emulsion adhesive has the function of improving the adhesiveness and flexibility of the adhesive electrode. Therefore, by including the water-based emulsion adhesive in the adhesive electrode, the adhesive electrode can be made less elastic and its ability to conform to the irregularities on the surface of the skin 2 can be improved.

[0055] As the water-based emulsion adhesive, it is preferable to use an acrylic emulsion adhesive.

[0056] For acrylic emulsion adhesives, it is preferable to use a silane-based emulsion adhesive that contains a water-dispersible copolymer and an organic liquid component compatible with the water-dispersible copolymer.

[0057] Water-dispersible copolymers are polymers obtained by copolymerizing a monomer mixture containing an alkyl (meth)acrylate with a silane monomer copolymerizable with the alkyl (meth)acrylate.

[0058] A monomer mixture containing alkyl methacrylate is a monomer mixture that contains alkyl methacrylate as the main component, preferably in an amount of 50 wt% to 100 wt%.

[0059] As the alkyl (meth)acrylate ester, a linear or branched alkyl ester having 1 to 15 carbon atoms in the alkyl group, preferably 1 to 9 carbon atoms, is used. Specifically, examples include alkyl (meth)acrylate esters having a linear or branched alkyl group, such as methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, and tridecyl (meth)acrylate. These can be used alone or in combination of two or more.

[0060] A monomer mixture containing an alkyl (meth)acrylate may also contain a carboxyl group-containing monomer copolymerizable with the alkyl (meth)acrylate.

[0061] The carboxyl group-containing monomer copolymerizable with alkyl (meth)acrylate is not particularly limited as long as it is a polymerizable compound containing a carboxyl group in its structure and copolymerizable with alkyl (meth)acrylate, but examples include (meth)acrylic acid, itaconic acid, maleic acid, maleic anhydride, and 2-methacryloyloxyethyl succinic acid. Acrylic acid is particularly preferred.

[0062] From the viewpoint of hydrolysis of the silane monomer and adjustment of the resulting viscosity, it is preferable to include the carboxyl group-containing monomer in an amount of 0.1 wt% to 10 wt% relative to 100 wt% of the monomer mixture containing the alkyl (meth)acrylate.

[0063] Silane monomers copolymerizable with alkyl (meth)acrylates are not particularly limited as long as they are polymerizable compounds having silicon atoms and copolymerizable with alkyl (meth)acrylates. However, silane compounds having a (meth)acryloyl group, such as (meth)acryloyloxyalkylsilane derivatives, are preferred because they exhibit excellent copolymerizability with alkyl (meth)acrylates. Examples of silane monomers include 3-(meth)acryloyloxypropyltrimethoxysilane, 3-(meth)acryloyloxypropyltriethoxysilane, 3-(meth)acryloyloxypropylmethyldimethoxysilane, and 3-(meth)acryloyloxypropylmethyldiethoxysilane. These silane monomers can be used individually or in combination of two or more.

[0064] In addition, other silane monomers that can be used include, for example, vinyltrimethoxysilane, vinyltriethoxysilane, 4-vinylbutyltrimethoxysilane, 4-vinylbutyltriethoxysilane, 8-vinyloctyltrimethoxysilane, 8-vinyloctyltriethoxysilane, 10-methacryloyloxydecyltrimethoxysilane, 10-acryloyloxydecyltrimethoxysilane, 10-methacryloyloxydecyltriethoxysilane, and 10-acryloyloxydecyltriethoxysilane.

[0065] It is preferable to copolymerize the silane monomer with a monomer mixture containing an alkyl (meth)acrylate at a concentration of 0.005 wt% to 2 wt% per 100 wt% of the monomer mixture containing the alkyl (meth)acrylate.

[0066] By copolymerizing silane monomers with a monomer mixture containing alkyl (meth)acrylate esters, the silane compounds that act as crosslinking points are uniformly distributed within the molecules of the resulting copolymer. As a result, the aqueous emulsion adhesive, despite being water-dispersible, exhibits excellent cohesiveness because the inside and outside of the particles are uniformly crosslinked. In addition to being low in skin irritation due to the addition of organic liquid components, it also possesses excellent fixation and sweat-resistant properties.

[0067] The water-dispersible copolymer may, if necessary, be obtained by copolymerizing monomers copolymerizable with alkyl (meth)acrylates other than the silane monomers and carboxyl group-containing monomers mentioned above. Monomers copolymerizable with alkyl (meth)acrylates other than silane monomers and carboxyl group-containing monomers can be used for purposes such as adjusting the cohesive force of adhesive electrodes when forming water-based emulsion adhesives into sheets, or improving compatibility with organic liquid components. The amount used can be arbitrarily set according to the purpose by substituting a portion of the alkyl (meth)acrylate content.

[0068] Monomers copolymerizable with alkyl (meth)acrylates other than silane monomers and carboxyl group-containing monomers include, for example, sulfoxyl group-containing monomers such as styrene sulfonic acid, allyl sulfonic acid, sulfopropyl (meth)acrylate, (meth)acryloyloxynaphthalene sulfonic acid, and acrylamide methylpropane sulfonic acid; hydroxyl group-containing monomers such as hydroxyethyl (meth)acrylate and hydroxypropyl (meth)acrylate; amide group-containing monomers such as (meth)acrylamide, dimethyl (meth)acrylamide, N-butylacrylamide, N-methylol(meth)acrylamide, and N-methylolpropane(meth)acrylamide; alkylaminoalkyl (meth)acrylates such as aminoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, and tert-butylaminoethyl (meth)acrylate; and methoxypropyl (meth)acrylate. Examples include ethyl esters, ethoxyethyl (meth)acrylate alkoxyalkyl esters such as (meth)acrylate, methoxyethylene glycol (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, methoxyethylene glycol (meth)acrylate, methoxydiethylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, methoxypolypropylene glycol (meth)acrylate, etc., containing alkoxy groups (or ether links in the side chain), vinyl monomers such as (meth)acrylonitrile, vinyl acetate, vinyl propionate, N-vinyl-2-pyrrolidone, methylvinylpyrrolidone, vinylpyridine, vinylpiperidine, vinylpyrimidine, vinylpiperazine, vinylpyrazine, vinylpyrrole, vinylimidazole, vinylcaprolactam, vinyloxazole, and vinylmorpholine. These can be used alone or in combination of two or more.

[0069] Aqueous dispersible polymers can be prepared, for example, by subjecting a mixture of monomers containing an alkyl (meth)acrylate ester and a silane monomer to conventional emulsion polymerization, thereby producing an aqueous dispersion of an alkyl (meth)acrylate copolymer.

[0070] Common polymerization methods such as batch polymerization, continuous dropwise polymerization, and segmented dropwise polymerization can be employed, and the polymerization temperature is, for example, 20°C to 100°C.

[0071] The polymerization initiator used in polymerization is not particularly limited, and general components used as polymerization initiators can be used.

[0072] A chain transfer agent may be used to adjust the degree of polymerization. The chain transfer agent is not particularly limited, and general components used as chain transfer agents can be used.

[0073] In addition to the method described above, the water-dispersible copolymer may also be prepared by obtaining a copolymer of a monomer mixture containing (meth)acrylic acid ester and a silane monomer by a method other than emulsion polymerization, and then dispersing it in water with an emulsifier.

[0074] The organic liquid components contained in the acrylic emulsion adhesive, when incorporated into a water-dispersible copolymer, maintain good adhesion to the surface of the skin 2, reduce keratin damage during peeling from the surface of the skin 2, and also reduce pain during peeling.

[0075] The organic liquid component is preferably liquid at room temperature and has good compatibility with the water-dispersible copolymer. "Compatibility" refers to a state where the organic liquid component is uniformly dissolved and incorporated into the water-dispersible copolymer, and separation cannot be observed visually.

[0076] Examples of organic liquid components include esters of monobasic or polybasic acids with 8 to 18 carbon atoms and branched alcohols with 14 to 18 carbon atoms, and esters of unsaturated fatty acids or branched acids with 14 to 18 carbon atoms and alcohols with tetrahydride or less.

[0077] Examples of esters of monobasic or polybasic acids with 8 to 18 carbon atoms and branched alcohols with 14 to 18 carbon atoms include isostearyl laurate, isocetyl myristate, octyldodecyl myristate, isostearyl palmitate, isocetyl stearate, octyldodecyl oleate, diisostearyl adipate, diisocetyl sebacate, trioleyl trimellitate, and triisocetyl trimellitate.

[0078] Examples of unsaturated or branched fatty acids with 14 to 18 carbon atoms include myristoleic acid, oleic acid, linoleic acid, linolenic acid, isopalmitic acid, and isostearic acid.

[0079] Examples of alcohols with a tetravalent or lower valency include ethylene glycol, propylene glycol, glycerin, trimethylolpropane, pentaerythritol, and sorbitan.

[0080] The content of the organic liquid component can be arbitrarily set as appropriate depending on the type of water-dispersible copolymer and organic liquid component, for example, it may be 20 wt% to 80 wt% relative to 100 wt% of the water-dispersible copolymer.

[0081] When the acrylic emulsion adhesive is a silane emulsion adhesive, the acrylic emulsion adhesive can specifically be a silane emulsion adhesive containing 2-ethylhexyl acrylate, methyl methacrylate, acrylic acid, and 3-methacrylateoxypropyltrimethoxysilane.

[0082] Furthermore, acrylic emulsion adhesives can be two- or three-component acrylic emulsion adhesives containing a monomer mixture including an alkyl (meth)acrylate ester and a carboxyl group-containing monomer. These may contain solvents and other components in appropriate amounts within a range that allows them to perform effectively.

[0083] The monomer mixtures containing alkyl (meth)acrylates in two- or three-component acrylic emulsion adhesives are similar to the monomer mixtures containing alkyl (meth)acrylates in the silane-based emulsion adhesives described above, so details are omitted.

[0084] The carboxyl group-containing monomer is preferably a carboxyl group-containing monomer copolymerizable with alkyl (meth)acrylate. Since the carboxyl group-containing monomer copolymerizable with alkyl (meth)acrylate is the same as the carboxyl group-containing monomer included in the above-mentioned monomer mixture containing alkyl (meth)acrylate, details are omitted.

[0085] Specifically, as a two-component acrylic emulsion adhesive, an adhesive can be used that contains 2-ethylhexyl acrylate, which is a monomer mixture containing an alkyl (meth)acrylate ester, and acrylic acid, which is a monomer mixture containing a carboxyl group.

[0086] Specifically, as a three-component acrylic emulsion adhesive, an adhesive can be used that contains 2-ethylhexyl acrylate and methyl methacrylate, which are monomer mixtures containing alkyl (meth)acrylate esters, and acrylic acid, which is a monomer mixture containing carboxyl groups.

[0087] The average particle size of the aqueous emulsion adhesive is preferably 100 nm to 1.0 μm, more preferably 100 nm to 500 nm, and even more preferably 100 nm to 300 nm. When the average particle size is within the above preferred range, adhesive strength and water resistance can be imparted to the adhesive electrode.

[0088] The shape of the aqueous emulsion adhesive is not particularly limited and may be spherical, ellipsoidal, fusiform, crushed, plate-like, columnar, etc.

[0089] The average particle diameter refers to the volume-average particle diameter based on the effective diameter. The average particle diameter is the particle diameter (median diameter) at which the cumulative amount of the smallest particles accounts for 50% of the volume in the particle size distribution curve obtained by measuring the particle size distribution of an emulsion adhesive or acrylic emulsion adhesive using methods such as laser diffraction / scattering or dynamic light scattering.

[0090] The content of the aqueous emulsion adhesive is preferably 35 wt% to 90 wt%, more preferably 40 wt% to 85 wt%, and even more preferably 50 wt% to 80 wt%, based on 100 wt% of the adhesive electrode. When the content of the aqueous emulsion adhesive is within the above preferred range, it is possible to impart adhesive strength and flexibility to the adhesive electrode while suppressing a decrease in conductivity.

[0091] The neutralizing agent contained in the adhesive electrode exhibits a neutralizing effect on the conductive polymer, neutralizing the conductive polymer and improving its flexibility. If the conductive polymer is, for example, PEDOT-PSS, even if PEDOT-PSS has acidic properties, the neutralizing effect can be effectively exerted on PEDOT-PSS, thereby effectively neutralizing PEDOT-PSS.

[0092] Suitable neutralizing agents include, for example, imidazole compounds.

[0093] Imidazole compounds are organic structures containing an imidazole group. The imidazole group in imidazole compounds acts as a neutralizing agent, for example, in the pH range of 3.5 to 6.5. Examples of imidazole compounds include heterocyclic amines.

[0094] Examples of heterocyclic amines include imidazole, 2-methylimidazole, 2-propylimidazole, 2-undecylimidazole, 2-phenylimidazole, N-methylimidazole, 1-(2-hydroxyethyl)imidazole, 2-ethyl-4-methylimidazole, 1,2-dimethylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, and 1-cyanoethyl Examples include 2-ethyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 1-acetylimidazole, 4,5-imidazole dicarboxylic acid, 4,5-imidazole dicarboxylic acid dimethyl, benzimidazole, 2-aminobenzimidazole, 2-aminobenzimidazole-2-sulfonic acid, 2-amino-1-methylbenzimidazole, 2-hydroxybenzimidazole, and 2-(2-pyridyl)benzimidazole. Among these, imidazole is preferred. The neutralizing agent and imidazole compounds may be used individually or in combination of two or more.

[0095] The neutralizing agent content is preferably 0.5 wt% to 2.4 wt%, more preferably 0.7 wt% to 2.2 wt%, and even more preferably 1.0 wt% to 2.0 wt%, based on 100 wt% of the adhesive electrode.

[0096] The humectant contained in the adhesive electrode has the function of improving the conductivity of the adhesive electrode, as well as improving its adhesive strength and flexibility.

[0097] Examples of humectants include glycerin, ethylene glycol, propylene glycol, sorbitol, polyol compounds such as polymers thereof, N-methylpyrrolidone (NMP), dimethylformaldehyde (DMF), N-N'-dimethylacetamide (DMAc), dimethyl sulfoxide (DMSO), and other aprotic compounds. These may be used individually or in combination of two or more. Among these, glycerin is preferred from the viewpoint of compatibility with other components.

[0098] The humectant content is preferably 2 wt% to 60 wt%, more preferably 3 wt% to 50 wt%, and even more preferably 5 wt% to 35 wt%, relative to 100 wt% of the adhesive electrode. If the humectant content is within the above preferred range, the adhesive strength of the adhesive electrode can be improved, maintaining high adhesion to the surface of the skin 2, while also reducing the storage modulus and increasing viscoelasticity, thereby suppressing the magnitude of noise generated during use. In addition, the adhesive electrode can suppress water absorption from the outside and prevent swelling.

[0099] The thickness of the electrode 20 may be any height as appropriate, for example, 10 μm to 100 μm. When the thickness of the electrode 20 is within the above preferred range, sufficient strength and flexibility can be provided to the electrode 20.

[0100] [Second layer member] As shown in Figure 4, the second layer member 30 is provided on the skin 2 side of the electrode 20 and sensor unit 50, and serves as a support substrate for installing the electrode 20 and sensor unit 50, as well as forming a part of the surface that adheres to the skin 2. By installing the sensor unit 50 on its upper surface 301 via the electrode 20, the contact of sweat generated on the skin 2 with the sensor unit 50 can be reduced. As shown in Figures 2 and 3, the external shape of the second layer member 30 may be substantially the same as the external shape of the first base material 10.

[0101] As shown in Figure 4, the second layer member 30 has exposed portions 30a on both ends in its longitudinal direction that expose a part of the electrode 20.

[0102] The exposed portion 30a is formed in a substantially circular shape in a plan view of the biosensor 1 and may be smaller than the exposed portions 202A and 202B of the electrode 20. The shape of the exposed portion 30a in a plan view is such that the exposed portions 202A and 202B of the electrode 20 do not fall into the exposed portion 30a and parts other than the electrode 20 are not exposed. In addition to a substantially circular shape, it may be other shapes such as a substantially elliptical or substantially rectangular shape.

[0103] The second layer member 30 may have a second base material 31, a first adhesive layer 32 provided on the upper surface 311 of the second base material 31, and a second adhesive layer 33 provided on the lower surface 312 of the second base material 31. The second base material 31, the first adhesive layer 32, and the second adhesive layer 33 may be formed to have the same shape in a plan view. The second adhesive layer 33 of the second layer member 30 and the electrode 20 form an adhesive surface to be attached to the skin 2. Depending on the area of ​​the electrode 20 and the second adhesive layer 33, and depending on the position of the adhesive surface, the waterproofness and breathability and adhesiveness can be made to differ. Therefore, depending on the area of ​​the adhesive surface of the second adhesive layer 33, the waterproofness and breathability, as well as the adhesiveness, can be made to differ.

[0104] The second layer member 30, like the first base material 10, has through holes 30b in a plan view of the biosensor 1 at positions corresponding to the protrusions 412 of the first housing 41. The through holes 30b are composed of through holes 31b in the second base material 31, through holes 32b in the first adhesive layer 32, and through holes 33b in the second adhesive layer 33. The through holes 30b only need to be large enough for the protrusions 412 of the first housing 41 to pass through.

[0105] The through-hole 30b is formed in a substantially rectangular shape in a plan view of the biosensor 1, but it is sufficient for the projection 412 to pass through, and it may be formed in other shapes such as a substantially circular or substantially elliptical shape.

[0106] Four through holes 30b are provided in the second layer member 30 so as to correspond to the projections 412, but the number of through holes 30b can be three or fewer, or six or more, as long as they are in positions corresponding to the projections 412.

[0107] (Second base material) The second base material 31 can be formed using a flexible resin having appropriate elasticity, flexibility, and toughness. Examples of materials that can be used to form the second base material 31 include polyester resins such as polyethylene terephthalate (PET), polybutylene terephthalate, polytrimethylene terephthalate, polyethylene naphthalate, and polybutylene naphthalate; acrylic resins such as polyacrylic acid, polymethacrylic acid, polymethyl polyacrylate, polymethyl methacrylate (PMMA), polyethyl polymethacrylate, and polybutylene acrylate; polyolefin resins such as polyethylene and polypropylene; polystyrene 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 resins; polyurethane resins; silicone resins; and polyvinyl chloride resins such as polyvinyl chloride and vinyl acetate copolymer resins. Among these, polyolefin resins and PET are preferably used. These thermoplastic resins have waterproof properties that do not allow moisture and water vapor to pass through (low moisture permeability). Therefore, by forming the second substrate 31 using these thermoplastic resins, when the biosensor 1 is attached to the skin 2 of a living body, it is possible to prevent sweat or water vapor generated from the skin 2 from passing through the second substrate 31 and entering the flexible substrate 51 side of the sensor part 50.

[0108] The second substrate 31 is preferably formed in a flat plate shape because the electrode 20 and sensor portion 50 are installed on its upper surface 311 side via the first adhesive layer 32.

[0109] The thickness of the second substrate 31 can be arbitrarily selected as appropriate, for example, from 1 μm to 300 μm.

[0110] The second substrate 31 has a first adhesive layer 32 on its upper surface 311 and a second adhesive layer 33 on its lower surface 312, but the first adhesive layer 32 and the second adhesive layer 33 do not necessarily have to be provided on the second substrate 31. In this case, it is preferable that the second substrate 31 has adhesive on at least one of its upper surface 311 and lower surface 312. If the second substrate 31 has adhesive on its upper surface 311 and lower surface 312, the second substrate 31 can be attached to the first substrate 10 and the electrode 20, and can also be attached to the skin 2.

[0111] (1st adhesive layer) As shown in Figure 4, the first adhesive layer 32 is provided on the upper surface 311 of the second base material 31 on the second housing 42 side (+Z axis direction), and the first base material 10, electrode 20, and sensor part 50 are bonded to it. Both ends of the first adhesive layer 32 of the second layer member 30 are provided in positions facing the opposing portions 201A and 201B of the electrode 20. This allows the opposing portions 201A and 201B of the electrode 20 and the terminals (not shown) of the sensor part 50 to be pressed and sandwiched between the first base material 10 and the second layer member 30, and enables electrical contact between the electrode 20 and the terminals (not shown) of the sensor part 50.

[0112] Since the first adhesive layer 32 can be made of the same material as the second adhesive layer 33 described later, details will be omitted.

[0113] Furthermore, the first adhesive layer 32 does not necessarily need to be provided on the second substrate 31, and may be omitted.

[0114] (2nd adhesive layer) As shown in Figure 4, the second adhesive layer 33 is provided on the lower surface 312 of the second substrate 31 on the adhesive side (-Z axis direction) and is the layer that comes into contact with the skin 2.

[0115] The second adhesive layer 33 preferably has pressure-sensitive adhesive properties. The pressure-sensitive adhesive properties of the second adhesive layer 33 allow the biosensor 1 to be easily attached to the skin 2 by pressing it against the skin 2 of a living body.

[0116] The material of the second adhesive layer 33 is not particularly limited as long as it is a pressure-sensitive adhesive material, and biocompatible materials are also available. Examples of materials for forming the second adhesive layer 33 include acrylic pressure-sensitive adhesives and silicone pressure-sensitive adhesives. Preferably, an acrylic pressure-sensitive adhesive is used.

[0117] Acrylic pressure-sensitive adhesives preferably contain an acrylic polymer as their main component. The acrylic polymer can function as a pressure-sensitive adhesive component. As the acrylic polymer, a polymer can be used that contains (meth)acrylic acid esters such as isononyl acrylate and methoxyethyl acrylate as the main component, and polymers obtained by polymerizing monomer components that can copolymerize with (meth)acrylic acid esters such as acrylic acid as optional components.

[0118] The acrylic pressure-sensitive adhesive preferably further contains a carboxylic acid ester. The carboxylic acid ester functions as a pressure-sensitive adhesive strength modifier that reduces the pressure-sensitive adhesive strength of the acrylic polymer and adjusts the pressure-sensitive adhesive strength of the second adhesive layer 33. The carboxylic acid ester can be a carboxylic acid ester that is compatible with the acrylic polymer. Examples of carboxylic acid esters include triglycerides.

[0119] Acrylic pressure-sensitive adhesives may contain a crosslinking agent as needed. 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.

[0120] The second adhesive layer 33 preferably has excellent biocompatibility. For example, when the second adhesive layer 33 is subjected to a keratin exfoliation test, the keratin exfoliation area ratio is preferably 0% to 50%. If the keratin exfoliation area ratio is within the range of 0% to 50%, the load on the skin 2 can be suppressed even when the second adhesive layer 33 is applied to the skin 2.

[0121] The second adhesive layer 33 preferably has moisture permeability. This allows water vapor and other substances generated from the skin 2 to which the biosensor 1 is attached to escape to the first substrate 10 side through the second adhesive layer 33. Furthermore, if the first substrate 10 is formed using a foam having a cellular structure as described above, water vapor can be released to the outside of the biosensor 1 through the second adhesive layer 33. This prevents sweat or water vapor from accumulating at the interface between the skin 2 to which the biosensor 1 is attached and the second adhesive layer 33. As a result, the moisture accumulated at the interface between the skin 2 and the second adhesive layer 33 weakens the adhesive force of the second adhesive layer 33, preventing the biosensor 1 from peeling off the skin 2.

[0122] The moisture permeability of the second adhesive layer 33 is, for example, 300 g / m². 2 • day) ~ 10000g / (m 2 It is preferable that the moisture permeability of the second adhesive layer 33 is within the above preferred range. If the second adhesive layer 33 is attached to the skin 2, sweat and other substances generated from the skin 2 can be appropriately permeated from the second adhesive layer 33 to the outside, thereby reducing the burden on the skin 2.

[0123] The thickness of the second adhesive layer 33 can be arbitrarily selected as appropriate, and is preferably between 10 μm and 300 μm. If the thickness of the second adhesive layer 33 is between 10 μm and 300 μm, the biosensor 1 can be made thinner.

[0124] [Cabinet] As shown in Figures 2 and 3, the pair of housings 40 are positioned so as to sandwich the first base material 10, the electrode 20, and the second layer member 30 between the upper surface 102 of the first base material 10 and the lower surface 302 of the second layer member 30. The pair of housings 40 has a first housing 41 provided on the skin 2 side (attachment side) and a second housing 42 provided on the opposite side (outside) from the skin 2. The first housing 41 and the second housing 42 sandwich the first base material 10, the electrode 20, and the second layer member 30 while pressing them together.

[0125] As shown in Figures 2 and 4, the first housing 41 is located on the outermost side (-Z axis direction) of the attachment side of the biosensor 1 and is in contact with the skin 2.

[0126] The first housing 41 has a plate-shaped base 411 and a projection 412 that protrudes from the base 411 toward the second housing 42.

[0127] The base body 411 has a flat main surface facing the second layer member 30, and may be formed in an elliptical shape in a plan view. The shape of the base body 411 in a plan view may be rectangular or the like.

[0128] The projections 412 may be provided in four positions that allow them to be inserted into the through-holes 12 of the first base material 10 and the through-holes 30b of the second layer member 30. As shown in Figure 5, the projections 412 have a height that allows them to penetrate the through-holes 12 and 30b and engage with the locking portion 421 of the second housing 42.

[0129] The projection 412 may have a flange 412a projecting from its tip edge in the circumferential direction, which is perpendicular to the height direction (Z-axis direction). The flange 412a may have a lower surface formed substantially parallel to the circumferential direction of the projection 412. The lower surface of the flange 412a is placed on the upper surface of the locking portion 421, and the projection 412 is locked to the locking portion 421 of the second housing 42, thereby enabling the first housing 41 to engage with the second housing 42.

[0130] The number of protrusions 412 is not particularly limited and may be any number as appropriate depending on the size of the base 411, etc.

[0131] As shown in Figures 2 and 4, the second housing 42 is located on the outermost side (+Z axis direction) of the biosensor 1 and is bonded to the upper surface 101 of the first substrate 10. The second housing 42 is formed in a roughly dome shape in the height direction (+Z axis direction) of Figure 1 so as to have space inside.

[0132] The second housing 42 has a recess 42a formed in a concave shape on its inner side (attachment side) facing the skin 2. On the inner side (attachment side) of the second housing 42, a storage space S for housing the sensor unit 50 is formed by the recess 42a on the inner surface of the second housing 42, the electrode 20, and the second layer member 30.

[0133] As shown in Figure 5, the second housing 42 has a locking portion 421 on the inner surface of its lower edge that engages with the projection 412. The locking portion 421 is formed on the inner surface of the lower edge of the second housing 42, protruding in a direction substantially perpendicular to the height direction (Z-axis direction), and is capable of contacting the lower surface of the flange portion 412a.

[0134] The number of locking portions 421 should be provided in accordance with the number of projections 412.

[0135] The first housing 41 and the second housing 42 press against the first base material 10, the electrode 20, and the second layer member 30 with their projections 412 locked to the locking portion 421. In this embodiment, the first housing 41 and the second housing 42 are locked together by the projection 412 of the first housing 41 and the locking portion 421 of the second housing 42, but other configurations are also acceptable as long as the first housing 41 and the second housing 42 can be locked together.

[0136] The material used to form the housing 40 may be a material with insulating properties and high strength, or a flexible material. By forming the housing 40 using the above-mentioned flexible material, the hardness of the housing 40 can be increased, thereby suppressing a decrease in the waveform accuracy of the measured biological signal when measuring the biological signal. In addition, the sensor unit 50, which is placed in the storage space S formed inside the second housing 42, is protected, and impacts applied to the biological sensor 1 from the top or bottom are absorbed, mitigating the impact applied to the sensor unit 50.

[0137] Examples of materials with insulating properties and high strength include polyester (PE) resins, polyacrylonitrile (PAN) resins, acrylic (PMMA) resins, polyimide (PE) resins, polycarbonate (PC) resins, polybutadiene (PBR) resins, polyethersulfone (PES) resins, polyetheretherketone (PEEK) resins, polysulfone (PS) resins, polyphenylene sulfide (PPS) resins, polyamide (PA) resins, polysiloxane resins, polystyrene (PS) resins, polyamideimide (PAI) resins, polyurethane (PU) resins, vinyl chloride (PVC) resins, polyvinylidene chloride (PVDC) resins, polypropylene (PP) resins, polytetrafluoroethylene (PTFE) resins, ABS resins, and polyphenylene oxide (PPO) resins. Among these, polycarbonate (PC) resins, polystyrene (PS) resins, and ABS resins are particularly noteworthy. These may be used individually or in combination of two or more types.

[0138] Flexible materials can include, for example, thermoplastic resins such as acrylic resins, polyurethane resins, polystyrene resins, polyolefin resins, silicone resins, vinyl chloride resins, and polyester resins, as well as thermoplastic elastomers and crosslinked rubbers.

[0139] 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 their hydrogenated derivatives, styrene-isoprene block copolymers or their hydrogenated derivatives, and the like. These may be used individually or in combination of two or more.

[0140] Examples of crosslinked rubbers 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 housing 40 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 housing 40 using the above-mentioned flexible material, the sensor part 50, which is placed in the storage space S formed inside the second housing 42, is protected, and the impact applied to the biosensor 1 from above is absorbed, mitigating the impact on the sensor part 50.

[0141] The thickness of the enclosure 40 can be designed as appropriate, for example, 1.5 mm to 3 mm.

[0142] The hardness of the second housing 42 can be designed to any appropriate size, for example, preferably between 10 and 40. The upper limit of the hardness is more preferably 30 or less. If the hardness of the second housing 42 is within the above preferred range, when the skin 2 is stretched due to body movement, the first base material 10, electrode 20, and second layer member 30 can be easily deformed in accordance with the movement of the skin 2 without being affected by the second housing 42. Note that hardness refers to Shore A hardness. In this specification, Shore A hardness refers to the hardness measured according to ISO 7619 (JIS K 6253-3:2012). As described in JIS K 6253-3:2012 "Vulcanized rubber and thermoplastic rubber - Method for determining hardness - Part 3: Durometer hardness", the measured value of Shore A hardness obtained by preparing a sheet sample of the second housing 42 can be taken as the Shore A hardness of the second housing 42.

[0143] [Sensor unit] As shown in Figures 2 and 3, the sensor unit 50 includes a flexible substrate 51, a sensor body 52, and a battery 53. The sensor unit 50 may have a connection portion (not shown) on the flexible substrate 51 that connects to the sensor body 52.

[0144] The flexible substrate 51 is a resin substrate on which various components for acquiring biological information are mounted, and the sensor body 52 and battery 53 may be placed on the flexible substrate 51.

[0145] The sensor body 52 acquires biological information and may have, for example, a component mounting section which is a control unit.

[0146] The component mounting section may include various components mounted on the flexible substrate 51, such as a CPU and integrated circuit that acquire biological information and process biological signals acquired from the body to generate biological signal data, a switch to activate the biological sensor 1, a flash memory for storing biological signals, and a light-emitting element. The component mounting section may transmit via wired or wireless connection to external devices such as an operation confirmation device for checking initial operation and a reading device for reading biological information from the biological sensor 1. Component mounting sections not shown may be powered by electricity supplied from a battery 53.

[0147] The unillustrated connection portion may, for example, include wiring (not shown) connected to the sensor body 52 in the longitudinal direction (Y-axis direction) of the sensor body 52, and a terminal portion (not shown) provided at one end (Y-axis direction) of the wiring (not shown) and connected to the electrode 20.

[0148] The battery 53 is installed on the flexible circuit board 51 and supplies power to an integrated circuit, etc., mounted on a component mounting section (not shown) of the sensor body 52. ​​The battery 53 may be a known battery. For example, a coin cell battery such as a CR2025 may be used as the battery 53.

[0149] As shown in Figures 2 and 3, when the biosensor 1 is not in use, it is preferable to attach the release liner 60 to the surfaces of the electrodes 20, second substrate 31, and second housing 42 that come into contact with the skin 2, in order to protect the electrodes 20, second substrate 31, and second housing 42 until use. When in use, the release liner 60 is peeled off from the electrodes 20, second substrate 31, and second housing 42, and the surface of the biosensor 1 is attached to the skin 2. By keeping the release liner 60 attached to the surface, the adhesive strength of the electrodes 20 and second layer member 30 can be maintained even if the biosensor 1 is stored for a long period of time. Therefore, when in use, the release liner 60 is peeled off from the electrodes 20, second substrate 31, and second housing 42, ensuring that the surface is securely attached to the skin 2 for use.

[0150] The method for manufacturing the biosensor 1 is not particularly limited and can be manufactured using any method as appropriate. An example of a method for manufacturing the biosensor 1 will be described below.

[0151] As shown in Figure 2, a first substrate 10, an electrode 20, a second layer member 30, a pair of housings 40, and a sensor unit 50 are prepared. Each of these components is not particularly limited as long as it can be manufactured using any method that is suitable for manufacturing them.

[0152] After preparing each component that makes up the biosensor 1 shown in Figure 2, the sensor unit 50 is placed on the second layer member 30. Then, the second layer member 30, the electrode 20, and the first base material 10 are stacked in that order from the second layer member 30 side toward the first base material 10 side, and sandwiched between a pair of housings 40. This results in the biosensor 1 shown in Figure 1.

[0153] Figure 6 is an explanatory diagram showing the biosensor 1 from Figure 1 attached to the chest of subject P. As shown in Figure 6, for example, the biosensor 1 is attached to the skin of subject P with its longitudinal direction (Y-axis direction) aligned with the sternum of subject P, with one electrode 20A on the upper side and the other electrode 20B on the lower side. The biosensor 1 is attached to the skin of subject P by the second adhesive layer 33 from Figure 4, and with the electrodes 20 pressed against the skin of subject P, it acquires biological signals such as electrocardiogram signals from subject P via the electrodes 20. The biosensor 1 stores the acquired biological signal data in a non-volatile memory such as a flash memory mounted on a component mounting section (not shown).

[0154] Thus, the biosensor 1 comprises a first substrate 10 and a pair of housings 40, the first housing 41 having a projection 412 and the second housing 42 having a locking portion 421. The biosensor 1 presses the first substrate 10 with the first housing 41 and the second housing 42 with the projection 412 locked to the locking portion 421. Because the first substrate 10 is flexible, by pressing the upper surface of the first substrate 10 from above with the first housing 41, the lower end of the second housing 42 can bite into the upper surface 101 of the first substrate 10, thereby locking the first housing 41 and the second housing 42. As a result, the biosensor 1 can prevent gaps from forming between the first substrate 10 and the second housing 42, thereby maintaining a sealed state of the housing space S inside the biosensor 1 and suppressing the intrusion of moisture from the outside. Therefore, the biosensor 1 can seal the housing space S inside the biosensor 1 with a simple configuration and exhibit waterproofness.

[0155] The biosensor 1 is equipped with electrodes 20, and the first base material 10 is provided on the side opposite to the skin 2 relative to the electrodes 20, and the projection 412 can be inserted into the through hole 12 of the first base material 10. By providing the electrodes 20 on the skin 2 side of the first base material 10 and inserting the projection 412 into the through hole 12 of the first base material 10, the first base material 10 and the electrodes 20 can be pressed while being sandwiched between the first housing 41 and the second housing 42. Therefore, even when the biosensor 1 is equipped with electrodes 20, it is possible to suppress the formation of a gap between the first base material 10 and the second housing 42, thereby maintaining a sealed state of the housing space S inside the biosensor 1 and suppressing the intrusion of moisture from the outside.

[0156] The biosensor 1 includes a second layer member 30 on the skin 2 side of the first base material 10 and electrode 20, and the second layer member 30 can be provided with an exposed portion 30a and a through hole 30b. The biosensor 1 can expose a part of the electrode 20 through the exposed portion 30a and insert a projection 412 into the through hole 30b. By exposing a part of the electrode 20 through the exposed portion 30a, the biosensor 1 can bring a part of the electrode 20 into contact with the skin 2. Furthermore, by inserting the projection 412 into the through hole 30b of the second layer member 30, the biosensor 1 can press the first base material 10, electrode 20 and second layer member 30 while sandwiched between the first housing 41 and the second housing 42. Therefore, even when the biosensor 1 is further equipped with a second layer member 30, it is possible to suppress the occurrence of a gap between the first base material 10 and the second housing 42, thereby maintaining a sealed state of the housing space S inside the biosensor 1 and suppressing the intrusion of moisture from the outside.

[0157] The biosensor 1 has a first adhesive layer 32 on the upper surface 311 of the second substrate 31 and a second adhesive layer 33 on the lower surface 312 of the second substrate 31, so that adhesive can be applied to both sides of the second substrate 31. This allows the biosensor 1 to improve the adhesion between the second substrate 31 and the first substrate 10 and the electrode 20. In addition, the second substrate 31 can be more firmly fixed in the second housing 42. As a result, the biosensor 1 can suppress displacement of the electrode 20 and maintain a stronger connection between the electrode 20 and the sensor body 52, thereby enabling stable measurement of biological signals.

[0158] The biosensor 1 can have a second substrate 31 that, in a plan view of the biosensor 1, has an external shape corresponding to the first substrate 10. As a result, the biosensor 1 can have a first adhesive layer 32 applied to the entire upper surface 311 of the second substrate 31, so that the entire upper surface 301 of the second layer member 30 can be attached to and joined to the first substrate 10. Since the interface between the first substrate 10 and the second layer member 30 is formed only on the side surface, external water is less likely to remain on the side surface between the first substrate 10 and the second layer member 30. Therefore, compared to the case where the interface between the first substrate 10 and the second layer member 30 is formed on the upper surface 301 of the second layer member 30, external water is less likely to penetrate from the interface between the first substrate 10 and the second layer member 30. Thus, the biosensor 1 can further enhance the waterproofness of the housing space S inside the biosensor 1.

[0159] The biosensor 1 can have its first substrate 10 made of a porous material. This allows the first substrate 10 to be made more flexible. As a result, when the surface of the skin 2 deforms due to body movement or the like, the biosensor 1 can easily deform the first substrate 10 in accordance with the deformation of the electrodes 20 and the second substrate 31. Therefore, the biosensor 1 can improve its ability to conform to the surface of the skin 2 and improve its adherence to the skin 2.

[0160] The biosensor 1 allows the first substrate 10 to be compressed by 10% to 40%. This suppresses warping of the first substrate 10, thereby reducing peeling from the skin 2 and improving adhesion to the skin 2. It also prevents gaps from forming between the housing 40 and the first substrate 10 or second layer member 30, thus maintaining waterproofness. Furthermore, when the surface of the skin 2 deforms due to body movement or the like, the biosensor 1 makes it easier to deform the first substrate 10 in accordance with the deformation of the electrodes 20 and the second layer member 30, thereby improving its conformability to the surface of the skin 2 and improving adhesion to the skin 2.

[0161] The biosensor 1 has a bending rigidity of 150 N·m 2The following can be achieved. As a result, the biosensor 1 can make the first substrate 10 softer and exhibit high flexibility, so when the surface of the skin 2 is deformed due to body movement, etc., the first substrate 10 can be easily deformed in accordance with the deformation of the electrode 20 and the second layer member 30. Therefore, the biosensor 1 can improve its conformability to the surface of the skin 2 and improve its adherence to the skin 2.

[0162] The biosensor 1 allows the thickness of the first substrate 10 to be 0.5 mm to 1.5 mm. This allows the first substrate 10 to be soft and highly flexible while maintaining waterproofness, and to be breathable. As a result, the biosensor 1 can improve its ability to follow the deformation of the skin surface 2 due to body movement, improve its adhesion to the skin 2, and suppress the formation of gaps between the housing 40 and the first substrate 10 or second layer member 30, thereby maintaining waterproofness. In addition, the biosensor 1 can improve the breathability of sweat produced on the skin 2, making it easier to release it to the outside.

[0163] The biosensor 1 has a first substrate 10 whose shape in plan view is formed with both ends in the longitudinal direction being arc-shaped. As a result, even if the surface of the skin 2 deforms in any direction due to body movement, the biosensor 1 can deform substantially the same way in all directions, and gaps between the skin 2 and the attachment surface of the biosensor 1 can be suppressed. Furthermore, even if the second layer member 30 deforms in accordance with the skin 2, the biosensor 1 can prevent sharp corners from forming on the outer shape of the second layer member 30 and piercing the skin 2, thereby reducing pain to the subject.

[0164] The biosensor 1 can be formed by including a conductive polymer in the electrode 20. This is because if the electrode 20 is formed using metal or the like, it may cause metal allergies or other problems in the subject, which can be burdensome for the subject. By forming the electrode 20 of the biosensor 1 with a conductive polymer, irritation to the subject's skin 2 is suppressed, and the burden on the subject can be reduced.

[0165] The biosensor 1 has an adhesive electrode 20 that can be attached to the skin 2 side of the first substrate 10. This enhances the adhesion of the electrode 20 to the first substrate 10 and the skin 2, allowing the electrode 20 to be firmly fixed between the first substrate 10 and the second layer member 30. Furthermore, the biosensor 1 can stably maintain the electrode 20 attached to the skin 2, and can suppress displacement of the electrode 20 even when body movement occurs. As a result, the biosensor 1 suppresses the generation of noise during measurement of biological signals and can be attached to the skin 2 more stably. Thus, the biosensor 1 can improve the detection accuracy of biological signals during use while maintaining adhesion to the skin 2.

[0166] The biosensor 1 can have an opening 11 in the first substrate 10. In a plan view of the biosensor 1, the opening 11 is located at a position corresponding to the second housing 42 and is larger than the outer dimensions of the sensor portion 50, so the biosensor 1 can reliably house the sensor portion 50 within the housing space S.

[0167] The biosensor 1 can have a storage space S formed by the opening 11, the second layer member 30, and the recess 42a of the second housing 42. The sensor unit 50 has a flexible substrate 51, a sensor body 52, and a battery 53, and requires a certain height. Since the storage space S can be formed by the opening 11, the upper surface 301 of the second layer member 30, and the inside of the recess 42a of the second housing 42, the height of the biosensor 1 can be reduced compared to when the sensor unit 50 is installed on the upper surface 101 of the first base material 10. Therefore, the biosensor 1 can be made thinner and thus more compact.

[0168] The biosensor 1 can have its second housing 42 formed in a dome shape. This makes it easier to create space inside the second housing 42, thus increasing the size of the storage space S formed by the inner wall of the second housing 42, the opening 11, and the second layer member 30. Therefore, the biosensor 1 can easily accommodate the sensor unit 50 within the storage space S, making it easier to house the sensor unit 50 within the storage space S.

[0169] As described above, the biosensor 1 can stably measure biological information from the skin 2 for a long period of time during use, and therefore can be effectively used as an adhesive-type biosensor that is attached to human skin 2, etc. The biosensor 1 can be suitably used, for example, in healthcare wearable devices that are attached to the skin of a living person and require high sensitivity for detecting electrocardiograms and a high level of noise suppression effect in electrocardiograms.

[0170] In this embodiment, the first housing 41 has a projection 412 and the second housing 42 has a locking portion 421. However, the first housing 41 may have a locking portion and the second housing 42 may have a projection, and the projection of the second housing 42 may be locked to the locking portion of the first housing 41.

[0171] In this embodiment, the first housing 41 and the second housing 42 may each have a projection and a locking portion that engages with one of the projections. That is, the first housing 41 may have a projection 412 and a locking portion that engages with the projection of the second housing 42, and the second housing 42 may have a projection and a locking portion 421 that engages with the projection 412 of the first housing 41.

[0172] In this embodiment, the second layer member 30 is composed of a second base material 31, a first adhesive layer 32, and a second adhesive layer 33. However, if the second base material 31 has an adhesive on at least one surface, at least one of the first adhesive layer 32 and the second adhesive layer 33 may be omitted.

[0173] As described above, embodiments have been explained, but these embodiments are presented as examples only, and the present invention is not limited by these embodiments. The above embodiments can be implemented in various other forms, and various combinations, omissions, substitutions, and modifications are possible without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents.

[0174] The embodiments of the present invention are, for example, as follows. <1> A biosensor that is attached to a living body, The sensor unit that acquires biometric information, A first substrate having flexibility, The first housing provided on the biological side, A second housing is provided on the opposite side of the living organism, Equipped with, One or both of the first housing and the second housing have a projection that is inserted into a through hole in the first substrate, One or both of the first housing and the second housing have a locking portion for engaging the projection, A biosensor in which the first substrate is pressed by the first housing and the second housing with the projection engaged with the locking portion. <2> The sensor body is equipped with electrodes provided on the biological side, The first substrate is provided on the side opposite to the biological tissue with respect to the electrode, The projection is inserted into the through hole of the first substrate. <1> The biosensor described above. <3> The second substrate is provided on the biological side relative to the electrode and has an exposed portion that exposes a part of the electrode, The second substrate has a through hole into which the projection is inserted. <2> The biosensor described above. <4> The second substrate has an adhesive on at least one surface. <3> The biosensor described above. <5> The second substrate has an adhesive layer on at least one of the surfaces facing the first substrate and the surfaces facing the living organism. <3> or <4> The biosensor described above. <6> The second substrate has an external shape corresponding to the first substrate in a plan view of the biosensor. <3> ~ <5> A biosensor described in any one of the following. <7> The first substrate is a porous body containing closed cells. <1> ~ <6> A biosensor described in any one of the following. <8> The compressibility of the first substrate is 10% to 40%. <1> ~ <7> A biosensor described in any one of the following. <9> The bending rigidity of the first substrate is 150 N·m 2 The following is <1> ~ <8> A biosensor described in any one of the following. <10> The thickness of the first substrate is 0.5 mm to 1.5 mm. <1> ~ <9> A biosensor described in any one of the following. <11> In a plan view, the first substrate is formed with both ends in the longitudinal direction in an arc shape. <1> ~ <10> A biosensor described in any one of the following. <12> The electrode contains a conductive polymer. <2> ~ <11> A biosensor described in any one of the following. <13> The electrode is adhesive and is attached to the biological side of the first substrate. <2> ~ <12> A biosensor described in any one of the following. <14> The first substrate has an opening in a plan view of the biosensor that is larger than or equal to the outer dimensions of the sensor body, at a position corresponding to at least one of the first housing and the second housing. <1> ~ <13> A biosensor described in any one of the following. [Explanation of Symbols]

[0175] 1. Biosensor 2 skin 10 First base material 11 Opening 12, 30b, 31b, 32b, 33b, 204A, 204B through hole 20, 20A, 20B electrode 30 Second layer member 30a exposed part 31 Second base material 32 1st adhesive layer 33 Second adhesive layer 40 cabinets 41. First cabinet 412 Protrusion 42 Second cabinet 42a depression 421 Locking part 50 Sensor section 52 Sensor body S Containment space

Claims

1. A biosensor that is attached to a living body, The sensor unit that acquires biometric information, A first substrate having flexibility, The first housing provided on the biological side, A second housing is provided on the opposite side of the living organism, Equipped with, One or both of the first housing and the second housing have a projection that is inserted into a through hole in the first substrate, One or both of the first housing and the second housing have a locking portion for engaging the projection, A biosensor in which the first substrate is pressed by the first housing and the second housing with the projection engaged with the locking portion.

2. The sensor body is equipped with electrodes provided on the biological side, The first substrate is provided on the side opposite to the biological tissue with respect to the electrode, The biosensor according to claim 1, wherein the projection is inserted into the through hole of the first substrate.

3. The second substrate is provided on the biological side relative to the electrode and has an exposed portion that exposes a part of the electrode, The biosensor according to claim 2, wherein the second substrate has a through hole into which the projection is inserted.

4. The biosensor according to claim 3, wherein the second substrate has an adhesive on at least one surface.

5. The biosensor according to claim 4, wherein the second substrate has an adhesive layer on at least one of the surface facing the first substrate and the surface facing the living organism.

6. The biosensor according to claim 3, wherein the second substrate has an external shape corresponding to the first substrate in a plan view of the biosensor.

7. The biosensor according to claim 1, wherein the first substrate is a porous body containing closed cells.

8. The biosensor according to claim 1, wherein the compressibility of the first substrate is 10% to 40%.

9. The bending rigidity of the first substrate is 150 N·m ２ The biosensor according to claim 1, wherein the biosensor is as follows:

10. The biosensor according to claim 1, wherein the thickness of the first substrate is 0.5 mm to 1.5 mm.

11. The biosensor according to claim 1, wherein the first substrate has both ends in the longitudinal direction formed in an arc shape when viewed in plan.

12. The biosensor according to claim 2, wherein the electrode comprises a conductive polymer.

13. The biosensor according to claim 2, wherein the electrode is adhesive and is attached to the biological side surface of the first substrate.

14. The biosensor according to claim 1, wherein the first substrate has an opening in a plan view of the biosensor that is larger than or equal to the outer dimensions of the sensor body at a position corresponding to at least one of the first housing and the second housing.

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