Wetness sensor sheets, wetness detection sensor kits, and absorbent articles

Abstract

This technology provides a way to reliably detect wetting of absorbent materials and determine the amount of urine excreted, while keeping costs down. [Solution] A wet sensor sheet (1) is detachable from a transmitting unit (2) configured to transmit to an external computer and is formed as part of an absorbent article or can be attached to an absorbent article. The wet sensor sheet (1) comprises a water-permeable sheet (10) and a circuit section provided on the water-permeable sheet and supplied with power from the transmitting unit (2). The circuit section includes a power receiving section that receives power from the transmitting unit and a sensor circuit section (12) that is electrically connected to the power receiving section and printed in a position that comes into contact with urination. The sensor circuit section (12) is configured such that the circuit constant changes in stages according to the amount of urination.

Description

Technical Field

[0001] The present invention relates to a technique for detecting wetness of absorbent articles.

Background Art

[0002] Currently, various techniques for detecting wetness of absorbent articles such as diapers have been proposed. Such techniques include a method of detecting wetness without directly touching urine (hereinafter referred to as an indirect detection method) and a method of detecting wetness by directly touching urine (hereinafter referred to as a direct detection method). Examples of the indirect detection method include a method of measuring temperature or humidity, a method of detecting odor, a method of detecting a change in capacitance, etc. Examples of the direct detection method include a method disclosed in Patent Document 1 below.

[0003] In the method disclosed in Patent Document 1 below, a pair of electrode pieces are provided so as to cover substantially the entire area where the absorbent is disposed, and by using the fact that the dielectric constant of the absorbent changes by absorbing urine, the presence or absence of urine is detected by detecting a change in impedance between the pair of electrode pieces. Further, Patent Document 2 below discloses a method in which an RFID (Radio Frequency Identification) tag is mounted on a diaper, and a moisture detection device detects the presence or absence of urination according to the communication status (such as reception efficiency and signal strength) with the RFID tag.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] Each of the conventional technologies described above has the following problems: For example, indirect detection methods are inferior to direct detection methods in terms of detection accuracy. Furthermore, while the method disclosed in Patent Document 2 mentioned above is promising in terms of detection accuracy because it employs a direct detection method, it has problems in terms of cost. In the direct detection method, the sensor part detects wetness by directly touching urine, and therefore it is assumed that it will be discarded each time the diaper is changed. However, since the sensor part employs a circuit that includes an active element such as an RFID tag, the cost of the sensor part itself becomes high. Furthermore, while the method disclosed in Patent Document 1 mentioned above may be able to detect the presence or absence of urine, it is difficult to detect the amount of urine excreted. Therefore, even if the user is informed of the presence or absence of urine using this method, they cannot determine whether an amount of urine has been excreted that requires a diaper change.

[0006] This invention has been made in view of these circumstances, and provides a technology that can reliably detect wetting of absorbent articles and determine the amount of urine excreted while keeping costs down. [Means for solving the problem]

[0007] According to the present invention, a wet sensor sheet is provided which is detachable from a transmitting unit configured to transmit to an external computer and is formed as part of an absorbent article or is formed to be attached to an absorbent article, comprising a water-permeable sheet and a circuit section provided on the water-permeable sheet and supplied with power from the transmitting unit, wherein the circuit section includes a power receiving section that receives power from the transmitting unit and a sensor circuit section that is electrically connected to the power receiving section and printed on a position that comes into contact with urination, and the sensor circuit section is configured such that the circuit constant changes in stages according to the amount of urination.

[0008] Furthermore, according to the present invention, a wetness detection sensor kit is provided, comprising a wetness sensor sheet and a transmitting unit separated from the wetness sensor sheet, wherein the transmitting unit includes a power supply, a power supply coil that receives power from the power supply, a resonant capacitor that forms a resonant circuit together with the power supply coil, a detection unit that measures parameter values ​​that enable the detection of changes in the circuit constants of the circuit portion of the wetness sensor sheet, and a transmitting processing unit that transmits information enabling the detection of changes in the circuit constants of the circuit portion to an external computer based on the detection by the detection unit.

[0009] Furthermore, according to the present invention, there is an absorbent article comprising the above-mentioned wet sensor sheet, wherein the absorbent article includes a connector for detachably connecting the transmitting unit, the power receiving section is a power receiving terminal that receives power from the transmitting unit, and the connector includes a wiring section that electrically connects the output terminal of the transmitting unit and the power receiving terminal when the transmitting unit is connected. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a technology that can reliably detect wetting of absorbent articles and determine the amount of urine excreted while keeping costs down. [Brief explanation of the drawing]

[0011] [Figure 1] This is a plan view showing an example of attaching the wet sensor sheet (this sensor sheet) according to the first embodiment to an absorbent article. [Figure 2] This figure shows the side of the wet sensor sheet (this sensor sheet) according to the first embodiment on which the circuit section is provided. [Figure 3] This is a schematic diagram showing an example of attaching the transmitting unit according to the first embodiment to an absorbent article. [Figure 4] This is a schematic block diagram showing the detailed configuration of the transmission unit according to the first embodiment. [Figure 5]This is a schematic diagram showing an example of attaching a transmission unit to an absorbent article including a wet sensor sheet (this sensor sheet) according to the second embodiment. [Figure 6] This figure shows the side of the wet sensor sheet (this sensor sheet) according to the second embodiment on which the circuit section is provided. [Modes for carrying out the invention]

[0012] The following describes embodiments of the present invention (hereinafter sometimes referred to as "these embodiments"). Note that the embodiments listed below are illustrative, and the present invention is not limited to the configurations of the embodiments described below.

[0013] First, we will describe the general configuration of the wetness detection sensor kit according to this embodiment (hereinafter sometimes referred to as "this kit"). This kit consists of a separable wet sensor sheet and a transmitting unit. Hereafter, the wet sensor sheet may be abbreviated as "this sensor sheet." "Separable" means that each component is formed in such a way that it can be separated into separate parts. The sensor sheet and the transmitting unit may, for example, be formed separately from each other and be used connected by a detachable connector, or they may be used in a completely separated state.

[0014] The transmitting unit is configured to transmit signals directly or indirectly to an external computer. That is, the transmitting unit may be configured to transmit signals directly to an external computer, or it may be configured to transmit signals to an external computer via a relay device (such as a cradle) that relays communications. In the former case, transmission to an external computer can be done using any communication method, such as short-range wireless communication methods like Wi-Fi (Local Area Network), Bluetooth®, or infrared communication. In the latter case, between the transmitting unit and the relay device, by adopting a low-power communication method such as Bluetooth Low Energy (BLE) (Bluetooth is a registered trademark), the power consumption of the transmitting unit can be reduced. Since the relay device only needs to receive power supply from a power source, various communication methods can be adopted between the relay device and an external computer. Note that in this case, the relay device may be configured to supply power to the transmitting unit. Also, the transmitting unit can detect changes in the circuit constants of the sensor sheet while supplying power to the sensor sheet, and transmit information based on this detection to the external computer. The external computer is a computer located outside the kit, and may be a portable user terminal such as a smartphone, a smartwatch, or a tablet terminal, or may be a stationary terminal such as a server device.

[0015] The wetness sensor sheet is formed as part of an absorbent article or is attachable to an absorbent article. "Absorbent article" means an article capable of absorbing liquid, such as disposable diapers, urine pads, menstrual pads, panty liners, toilet sheets for pets, etc. Therefore, the term "wearer" means a human or animal (pet) wearing an absorbent article or a wetness sensor sheet. However, the absorbent articles for which wetness is detected by the wetness sensor sheet are not limited to such examples.

[0016] The sensor sheet only needs to be arranged to come into contact with urine. It may be pre-incorporated (formed) as part of such an absorbent article, or may be formed separately from the absorbent article and attached to the absorbent article during use. For example, when the absorbent article is a urine pad, the sensor sheet may be housed inside the urine pad, or may be attached on the surface of the urine pad (the surface facing the wearer during use) or between the back surface of the urine pad and the underwear or diaper so as to fit within the plane of the urine pad in plan view.

[0017] This sensor sheet comprises at least a water-permeable sheet and a circuit section provided on the water-permeable sheet, which is powered by a transmitting unit. The circuit section includes a power receiving section that receives power from the transmitting unit, and a sensor circuit section that is electrically connected to the power receiving section and printed at a position that comes into contact with urination. The sensor circuit section is configured such that the circuit constants change in stages according to the amount of urine excreted. "A location that comes into contact with urination" means any location that comes into contact with urine, whether directly or indirectly. This includes, for example, a location that comes into direct contact with urination immediately after the wearer has urinated, and a location that, after the wearer has urinated, the urination overflows from the absorbent material of the absorbent article and comes into contact with the surface of the absorbent article or the wearer's skin. In this specification, when "comes into contact with urination" or "comes into contact with urine" is used, it means any location that comes into contact with urine, whether directly or indirectly. Furthermore, the amount of urine that triggers a gradual change in the circuit constants is the amount of urine excreted by the wearer, the amount of urine that overflows because it cannot be absorbed by the absorbent material of the absorbent product, or the amount of urine that passes through the permeable sheet of this sensor sheet. Therefore, "the circuit constant changes in stages according to the amount of urine excreted" means that, if the amount of urine excreted refers to the amount of urine excreted by the wearer or the amount of urine that passes through the permeable sheet, the circuit constant does not substantially change until it reaches a certain amount, and then changes in stages once it exceeds that amount; and if the amount of urine excreted refers to the amount of urine that overflows because it cannot be absorbed by the absorbent material of the absorbent article, then the circuit constant changes in stages according to the amount of overflowing urine.

[0018] In this sensor kit, the circuit constant of the wet sensor sheet changes when it comes into contact with urine. This change is detected by the transmission unit, and the information based on this detection is transmitted to an external computer. As a result, the user can reliably determine the wetness of the wearer's absorbent items based on the information received by the external computer. Furthermore, since the circuit section of this sensor sheet is configured so that the circuit constants change in stages according to the amount of urine excreted, the transmission unit can detect and transmit these staged changes in the circuit constants. As a result, the user can also understand the wetness of the absorbent material in accordance with the amount of urine excreted by the wearer.

[0019] Furthermore, this sensor kit achieves a lower cost for the sensor sheet, which is disposable due to direct contact with urination, by employing so-called passive circuits such as a power receiving unit and a printed sensor circuit section, rather than incorporating circuits containing active elements into the sensor sheet itself. On the other hand, expensive circuits (active circuits) such as the function of transmitting to an external computer and the power supply that provides power to the sensor sheet are mounted in a transmitting unit, and this transmitting unit is made separable from the disposable sensor sheet, enabling repeated use. This sensor kit allows for the use of inexpensive sensor sheets along with absorbent materials as disposable items, while the transmitting unit can be reused repeatedly, thereby reducing running costs.

[0020] Hereafter, we will provide specific examples to explain the details of the wetness detection sensor kit (this sensor kit) according to this embodiment. In the following examples, we will use the case where the absorbent item is a diaper and this sensor sheet is attached to the surface of the diaper (the side that faces the wearer when worn). In the following explanation, the position and orientation of each component of this sensor sheet and absorbent material will be indicated based on the correct wearing condition of the absorbent material. Specifically, the side that comes into contact with the wearer's skin will be referred to as the "wearer side," the opposite side as the "outside," the left-right direction of the wearer as the "left-right direction" or "width direction," and the front-to-back direction of the wearer as the "front-to-back direction."

[0021] [First Embodiment] In the wetness detection sensor kit according to the first embodiment, the sensor sheet and the transmitting unit are formed separately from each other and are used in a completely isolated state. Specifically, the sensor sheet is attached to the surface of the diaper (absorbent material) on the wearer's side so that it fits within the surface of the diaper when viewed from above, and the transmitting unit is attached to the outside of the diaper so as not to come into contact with urine.

[0022] <Wetness Sensor Sheet> Figure 1 is a plan view showing an example of attaching the wet sensor sheet (this sensor sheet) 1 according to the first embodiment to an absorbent article. In the example shown in Figure 1, the sensor sheet 1 is attached to a diaper 50, which is an absorbent item. Figure 1 shows the sides of the sensor sheet 1 and the diaper 50 that face the wearer.

[0023] The diaper 50 has an abdominal portion 51, a dorsal portion 52, and a connecting portion 53 that connects the abdominal portion 51 and the dorsal portion 52. The diaper is worn so that the abdominal portion 51 is located on the wearer's abdominal side, the dorsal portion 52 is located on the wearer's back side, and the connecting portion 53 is located in the wearer's crotch area. The abdominal portion 51 and the dorsal portion 52 are provided with side flaps that protrude on both the left and right sides, while the connecting portion 53, which is located in the wearer's crotch area, does not have side flaps. As a result, the connecting portion 53 is formed to be narrower than the abdominal portion 51 and the dorsal portion 52. A pair of fastening tapes 54 are provided at the ends of each side flap of the dorsal portion 52. When wearing the diaper, the fastening tapes 54 on both sides are wrapped around from each side of the waist to the outer surface of the ventral portion 51 and fastened to the outer surface of the ventral portion 51. Although Figure 1 shows an example of a tape-type diaper with fastening tapes 54, this sensor sheet 1 can also be attached to non-tape type pull-up diapers.

[0024] The diaper 50 has an absorbent body 55 between a water-permeable top sheet on the wearer's side and a water-impermeable back sheet on the outside, which is configured to absorb liquids (such as urine) discharged from the wearer. The absorbent body 55 extends in the front-to-back direction (longitudinal direction) from the ventral side 51 through the dorsal side 52 to the connecting part 53. Furthermore, the diaper 50 has a pair of three-dimensional gathers 57 extending in the longitudinal direction of the absorbent body 55 at both ends in the left-to-right direction (width direction) of the absorbent body 55. These three-dimensional gathers 57 prevent leakage of the diaper 50 in the width direction.

[0025] The sensor sheet 1 is attached to the wearer-side surface of the diaper 50 so as to fit within the plane of the absorbent material 55 in a plan view and extend from the crotch area of ​​the absorbent material 55 to one end in the longitudinal direction. In the example shown in Figure 1, the sensor sheet 1 is attached so as to extend from the crotch area of ​​the absorbent material 55 to the end of the ventral portion 51, but it may also be attached so as to extend from the crotch area to the end of the dorsal portion 52. As will be explained in more detail later, as shown by the dashed line in Figure 1, the sensor sheet 1 is installed so that the receiving coil 11 is positioned so as not to come into contact with urine (near the end of the ventral or dorsal portion 51 or 52 of the diaper 50), and the sensor circuit 12 is positioned so as to come into contact with urine.

[0026] When the diaper 50 is worn with the sensor sheet 1 attached in this manner, if the wearer urinates, the urine will pass through the sensor sheet 1 and be absorbed by the absorbent material 55 of the diaper 50. At this time, the urine will be absorbed by the absorbent material 55 from the area closest to the wearer's urination site, and any urine that cannot be absorbed and overflows will propagate to the area surrounding the absorbent material 55 and be absorbed thereafter. At this time, the sensor circuit portion of the sensor sheet 1 will come into contact with the urine, causing a change in the circuit constant. By detecting this change with the transmission unit, the wetness of the diaper 50 can be detected. In other words, the sensor sheet 1 can detect the wetness of absorbent items such as diapers 50 and can be used as a urination sensor to notify caregivers when it is time to change them. However, the diaper 50 to which this sensor sheet 1 is attached is not limited to the configuration shown in the example in Figure 1. This sensor sheet 1 can be used with diapers or urine pads of various configurations having an absorbent material 55.

[0027] Next, we will describe the detailed configuration of this sensor sheet 1. Figure 2 shows the side of the wet sensor sheet (this sensor sheet) 1 according to the first embodiment on which the circuit section is provided. This sensor sheet 1 comprises a water-permeable sheet 10 and a circuit section provided on one side of the water-permeable sheet 10.

[0028] The permeable sheet 10 is formed in a thin sheet shape and has a roughly rectangular planar shape. The permeable sheet 10 has the same external shape as the sensor sheet 1. The permeable sheet 10 has good water permeability and can be printed with the sensor circuit section 12 described later; its material and manufacturing method are not limited. However, the material of the permeable sheet 10 is preferably a synthetic fiber such as polyethylene, polypropylene, or polyethylene terephthalate that does not retain moisture. For example, the permeable sheet 10 is preferably made of a nonwoven fabric of 100% synthetic fibers with low water retention, such as spunbond nonwoven fabric, thermal bond nonwoven fabric, or air-through nonwoven fabric, and is hydrophilized to improve water permeability. The water-permeable sheet 10 is preferably made of a material that has water permeability equal to or greater than that of the top sheet on the wearer side of the absorbent article.

[0029] The circuit section is provided on the side of the sensor sheet 1 opposite to the wearer's side (the side with the diaper 50). However, the entire circuit section does not have to be provided on the same side of the sensor sheet 1, and the circuit section may be provided so as to be sandwiched between the water-permeable sheet 10. Thus, the form of the circuit section relative to the water-permeable sheet 10 is not limited.

[0030] The circuit section consists of the power receiving coil 11, which serves as the power receiving section, and the sensor circuit section 12, as described above. The power receiving coil 11 is located near one end of the permeable sheet 10 in the longitudinal direction (upper end in Figure 2), and the sensor circuit section 12 is connected to the power receiving coil 11 and extends from the power receiving coil 11 to the other end of the permeable sheet 10 in the longitudinal direction (lower end in Figure 2). In the example shown in Figure 1, the sensor sheet 1 is attached to the diaper 50 such that the receiving coil 11 is positioned near the end of the ventral portion 51 of the diaper 50. However, since it is sufficient that the receiving coil 11 is positioned so as not to come into contact with urine, the sensor sheet 1 may also be attached to the diaper 50 such that the receiving coil 11 is positioned near the end of the dorsal portion 52 of the diaper 50. In this way, the receiving coil 11 is positioned so as not to come into contact with urine, while the sensor circuit 12 is positioned so as to come into contact with urine.

[0031] The receiving coil 11 is powered using a magnetic field from the power supply coil 201 of the transmitting unit 2, which will be described later. As shown in Figure 2, the receiving coil 11 is provided on one side of the permeable sheet 10 such that the coil's central axis is perpendicular to the sheet surface of the permeable sheet 10. This allows the receiving coil 11 to receive the magnetic field generated by the current of the power supply coil of the transmitting unit 2, as will be described later, and generate an induced electromotive force.

[0032] The sensor circuit section 12 is connected to both ends of the power receiving coil 11 and includes a plurality of wiring pattern sections 13 and a plurality of specific circuit elements 15. The multiple wiring pattern sections 13 are printed on the water-permeable sheet 10 with conductive ink and are arranged in multiple stages to form parallel circuits with respect to the power receiving coil 11. In the example shown in Figure 2, seven stages of wiring pattern sections 13 are provided. Furthermore, the multi-stage configuration of the multiple wiring pattern sections 13 is arranged in the longitudinal direction of the sensor sheet 1. That is, the multiple wiring pattern sections 13 are arranged in multiple stages in the direction from the crotch area of ​​the wearer toward the ventral or dorsal side when the diaper 50 to which the wet sensor sheet 1 is attached is worn.

[0033] In this embodiment, the plurality of wiring pattern sections 13 include those that include a specific circuit element 15 (denoted as a specific wiring pattern section 14) and those that do not have a specific circuit element 15 and maintain a conductive state with the power receiving coil 11 (denoted as a conductive wiring pattern section 17). In the example in Figure 2, there are six specific wiring pattern sections 14 (denoted as reference numerals 14(1) to 14(6)) and one conductive wiring pattern section 17.

[0034] Each specific circuit element 15 is a circuit element that, upon contact with urine, short-circuits or disconnects the wiring pattern section 13 on which the specific circuit element 15 is provided. In the example in Figure 2, a short-circuit section that short-circuits the wiring pattern section 13 is exemplified as a specific circuit element 15, and one specific circuit element 15 is provided for each specific wiring pattern section 14. If each specific circuit element 15 is a disconnection function that disconnects the wiring pattern section 13 when it comes into contact with urine, this disconnection function will break, damage, dissolve, or weaken the conductor portion of the wiring pattern section 13 when it comes into contact with urine. The disconnection function may be realized as a conductor portion that dissolves when it comes into contact with urine, or it may be realized as a material that can apply an external force to the conductor portion of the wiring pattern section 13 when it comes into contact with (absorbs) urine, such as a water-absorbing and expanding material, and the conductor portion may be physically broken, damaged, or weakened by applying the external force.

[0035] As described above, each specific wiring pattern section 14 is arranged in multiple stages in the longitudinal direction of the sensor sheet 1, that is, from the crotch area of ​​the wearer toward the ventral or dorsal side. Therefore, each specific circuit element 15 is also arranged in multiple stages in the same direction.

[0036] Here, urination begins to be absorbed by the absorbent material 55 from the crotch area of ​​the wearer (near the wearer's urinary area), and any urine that cannot be absorbed in that area of ​​the absorbent material 55 overflows and is gradually propagated and absorbed towards the ventral or dorsal side, depending on the amount of urine. For this reason, in the specific circuit elements 15 which are arranged in multiple stages in the direction from the crotch area toward the ventral or dorsal side of the wearer, the specific circuit elements 15 in stages closer to the crotch area (stages farther from the receiving coil 11) come into contact with the urine in stages according to the amount of urine. As a result, the specific wiring pattern section 14 in stages closer to the crotch area (stages farther from the receiving coil 11) will be short-circuited or disconnected in stages according to the amount of urine. In the example in Figure 2, the specific circuit elements 15(6) to 15(1) come into contact with the urine in stages, and the specific wiring pattern section 14(6) to 14(1) will be short-circuited or disconnected in stages.

[0037] As described above, the multiple wiring pattern sections 13 are wiring patterns printed with conductive ink and do not contain active elements, so they can also be called passive circuit patterns. By printing the wiring pattern section 13 with conductive ink, the resistance value corresponding to the length of the wiring pattern section 13 can be made higher compared to copper foil wiring. As conductive inks, for example, those in which conductive fine particles of metal or carbon are dispersed in an organic solvent containing a dissolved thermoplastic resin can be used. However, the materials of the conductive ink are not limited in any way. Furthermore, the resistance of each wiring pattern section 13 increases in proportion to its wiring length. Since each wiring pattern section 13 is arranged in multiple stages in the longitudinal direction of the sensor sheet 1, that is, in the direction away from the power receiving coil 11, the longer the wiring distance from the power receiving coil 11, the higher the resistance of the wiring pattern section 13 (the wiring pattern section 13 located at the bottom of the page in Figure 2).

[0038] Therefore, depending on the amount of urine excreted, the total resistance value of the sensor circuit section 12 changes in stages according to the amount of urine excreted by gradually short-circuiting or opening the specific wiring pattern section 14 in the stage closest to the crotch area (stage farther from the power receiving coil 11). Specifically, if the specific circuit element 15 is implemented as a short-circuited section, the resistance value of the sensor circuit section 12 decreases as the amount of urine excreted increases, and if the specific circuit element 15 is implemented as an open section, the resistance value of the sensor circuit section 12 increases as the amount of urine excreted increases. In this embodiment, by detecting the stepwise change in the resistance value of the sensor circuit 12 using the transmission unit 2 described later, it becomes possible to determine not only the wetness of the diaper 50 but also the amount of urine excreted.

[0039] Furthermore, in this embodiment, the plurality of wiring pattern sections 13 include a conductive wiring pattern section 17 that does not have a specific circuit element 15 and maintains a conductive state with the power receiving coil 11. In the example in Figure 2, the conductive wiring pattern section 17 is provided at the position furthest from the power receiving coil 11, i.e., at or closest to the wearer's crotch. By providing at least one conductive wiring pattern section 17 in this manner, the sensor circuit section 12 can be kept in a conductive state both when none of the wiring pattern sections 13 are in contact with urine and when all of the wiring pattern sections 13 are in contact with urine. In this embodiment, one conductive wiring pattern section 17 is provided, but multiple conductive wiring pattern sections 17 may be provided. Alternatively, a configuration without conductive wiring pattern sections 17 may be provided. In this case, the sensor circuit section 12 will be in an open state when none of the wiring pattern sections 13 are in contact with urine, or when all of the wiring pattern sections 13 are in contact with urine, and the transmitting unit 2 may be configured to detect this.

[0040] Furthermore, in this embodiment, each specific circuit element 15 is distributed in the width direction (left-right direction) of the sensor sheet 1. In the example in Figure 2, specific circuit elements 15(1), 15(3), and 15(5) are located near one end of the sensor sheet 1 in the width direction (the left edge of the page in Figure 2), and specific circuit elements 15(2), 15(4), and 15(6) are located near the other end of the sensor sheet 1 in the width direction (the right edge of the page in Figure 2). As a result, even if the location of urine absorption and overflow propagation is shifted to the left or right depending on the wearer's body orientation, one of the specific circuit elements 15 will come into contact with the urine, thus reliably detecting that the diaper 50 is wet.

[0041] "Distributed arrangement" means that each specific circuit element 15 is arranged so that they are not aligned at the same position in the width direction (left-right direction) of the sensor sheet 1. This is not limited to placing each specific circuit element 15 near either the left edge or the right edge, as in the example in Figure 2, and there may also be specific circuit elements 15 placed in the center in the width direction. However, each specific circuit element 15 will come into contact with urine when it passes through the sensor sheet 1 before it is absorbed by the absorbent material 55. In this case, the change in circuit constant may not be maintained for a long time, and detection by the transmitting unit 2 may be temporary. Therefore, it is preferable that each specific circuit element 15 is not placed in a location that is likely to come into contact with urine passing through the sensor sheet 1, i.e., not in the center or its vicinity in the width direction of the sensor sheet 1, as illustrated in Figure 2.

[0042] However, it is preferable that each specific circuit element 15 is arranged such that adjacent specific circuit elements 15 in the direction of their multi-stage configuration, i.e., in the longitudinal direction of the sensor sheet 1, are not aligned at the same or adjacent positions in the width direction (left-right direction) of the sensor sheet 1. In particular, it is more preferable that the multiple specific circuit elements 15 included in each of the multiple wiring pattern sections 13 adjacent to each other in the longitudinal direction of the sensor sheet 1 be provided at positions on opposite sides in the width direction, with the center in the width direction of the sensor sheet 1 in between. In the example of Figure 2, the specific circuit element 15(2) is provided at the opposite side (near the right edge of the page) of the center of the specific wiring pattern section 14(2) on which it is provided, with respect to the left-right position (near the left edge of the page) of the specific circuit elements 15(1) and 15(3) adjacent to it in the multi-stage configuration direction (longitudinal direction). In the example of Figure 2, the adjacent specific circuit elements 15 are arranged in symmetrical positions, but each arrangement does not have to be symmetrical.

[0043] In this way, each specific circuit element 15 is alternately distributed to the left and right in the direction in which they are lined up (the direction of the multi-stage configuration). As a result, even if the absorption position of urination is biased to the left or right, the circuit constants will change in stages according to the amount of urination, and the amount of urination can be determined by detecting this change.

[0044] <Transmission Unit> Figure 3 is a schematic diagram showing an example of attaching the transmission unit 2 according to the first embodiment to an absorbent article. In Figure 3, the absorbent article is the diaper 50 shown in Figure 1. As shown in Figure 3, the transmission unit 2 is detachably attached to the outside of the ventral portion 51 of the diaper 50. The transmitting unit 2 is equipped with a fastening means (not shown) on one side of the outer case that houses the circuit board, power supply, etc., and is detachably attached to the outer surface of the ventral portion 51 of the diaper 50 via this fastening means. The fastening means is not limited in any way, but can be implemented, for example, by adhesive material such as hook-and-loop fasteners or double-sided tape. As will be explained in more detail later, the transmitting unit 2 is mounted in a position where the power supply coil 201 of the transmitting unit 2 (described later) and the power receiving coil 11 of the sensor sheet 1 face each other.

[0045] Next, we will describe the detailed configuration of the transmission unit 2. Figure 4 is a schematic block diagram showing the detailed configuration of the transmitter unit 2 according to the first embodiment. Each component illustrated in Figure 4 is formed on a substrate housed in the outer casing shown in Figure 3, for example. As illustrated in Figure 4, the transmission unit 2 includes a power supply circuit 20, a battery 21, a control unit 22, a detection unit 23, a transmission processing unit 24, a notification unit 25, an operation unit 26, and the like.

[0046] The power supply circuit 20 receives power from the battery 21 and generates a magnetic field based on that power, thereby transmitting (supplying) power to the circuit section (power receiving coil 11) of the sensor sheet 1. The power supply circuit 20 consists of a power supply coil 201, a resonant capacitor 202, a switching circuit 205, and the like. The power supply coil 201 forms a resonant circuit together with the resonant capacitor 202. In the example in Figure 4, the power supply coil 201 and the resonant capacitor 202 are connected in parallel to form a parallel resonant circuit, but they may also be connected in series to form a series resonant circuit.

[0047] The switching circuit 205 is connected to the resonant circuit and performs switching operations based on a drive signal from the control unit 22. The switching circuit 205 includes multiple switching elements and switches these switching elements in response to the drive signal from the control unit 22. As a result, a resonant current flows through the resonant circuit, generating a magnetic field in the power supply coil 201. Then, an induced electromotive force is generated in the power receiving coil 11 of the sensor sheet 1, which is positioned opposite the power supply coil 201, in accordance with this magnetic field.

[0048] In this embodiment, wireless power is supplied using electromagnetic induction from the power supply coil 201 of the mutually separated transmitting unit 2 to the power receiving coil 11 of the sensor sheet 1. Since power is supplied from the transmitting unit 2 to the sensor sheet 1 by wireless power transfer using a magnetic field, the circuit configuration of the power supply circuit 20 is not limited to the example shown in Figure 4. The circuit configuration of the power supply circuit 20 may include other circuit elements not shown in Figure 4.

[0049] Battery 21 is a DC power source and may be a primary battery or a secondary battery configured to store energy from an external power source connected via external terminals (not shown). In the latter case, battery 21 may be configured to store energy from an external power source by contactless power supply.

[0050] The detection unit 23 is configured to detect changes in the circuit constants of the circuit section (sensor circuit section 12) of the sensor sheet 1. The detection unit 23 sequentially measures the electrical characteristic values ​​of the resonant circuit formed by the power supply coil 201 and the resonant capacitor 202, and can detect changes in the circuit constants through changes in these electrical characteristic values. Examples of the electrical characteristics of the resonant circuit include the impedance and resonant frequency when viewing the circuit section of the sensor sheet 1 from the resonant circuit side. For example, the detection unit 23 sequentially measures the AC voltage and AC current in the power supply coil 201 of the power supply circuit 20, sequentially calculates the impedance when viewing the circuit section of the sensor sheet 1 from the power supply coil 201 side based on the measured AC voltage and AC current, and can detect changes in the circuit constants through changes in the calculated impedance. The detection unit 23 can also measure the resonant frequency of the resonant circuit and detect changes in the circuit constants through changes in that resonant frequency. However, the detection method for changes in circuit constants by the detection unit 23 is not limited to this example.

[0051] The detection unit 23 can also store parameter values ​​for detecting changes in the circuit constants of the sensor sheet 1's circuit section as reference values ​​when the operation unit 26, described later, is operated. For example, when the detection unit 23 is notified by the control unit 22 that the operation unit 26 has been operated, it may store the electrical characteristic values ​​(AC voltage, AC current, resonant frequency, etc.) of the resonant circuit measured at that time as the reference values, or it may store the circuit constants (impedance values, etc.) of the sensor sheet 1 derived from these electrical characteristic values ​​as the reference values. Thereafter, the detection unit 23 can detect changes in the circuit constants by comparing the stored reference values ​​with the measured electrical characteristic values ​​of the resonant circuit or the circuit constants derived from the measured values.

[0052] Here, the change in the electrical characteristics of the resonant circuit formed by the power supply coil 201 and the resonant capacitor 202 occurs not only in accordance with the change in the circuit constants on the secondary side when the power supply coil 201 is the primary side and the circuit portion of the sensor sheet 1 is the secondary side, but also in addition to the change in the positional relationship between the power supply coil 201 and the power receiving coil 11 of the sensor sheet 1. The coupling coefficient between coils changes depending on the relative positions of the coils, i.e., the distance between coils and axial misalignment. When the coupling coefficient decreases, the power transmission efficiency between coils also decreases. Therefore, when the relative positions of the coils result in a small coupling coefficient, the amount of change in the electrical characteristics of the resonant circuit due to changes in the circuit constants of this sensor sheet 1 becomes small, making it difficult to detect changes in the circuit constants.

[0053] Therefore, the detection unit 23 is configured to detect the positional relationship between the power supply coil 201 and the power receiving coil 11 of the sensor sheet 1. For this reason, the detection unit 23 can also be called a position detection unit. For example, the detection unit 23 holds a threshold value for the electrical characteristic value of the resonant circuit in which changes in the circuit constants of the sensor sheet 1 can be detected, and can determine whether the positional relationship between the power supply coil 201 and the power receiving coil 11 is appropriate by comparing the measured electrical characteristic value of the resonant circuit with the threshold value. An appropriate positional relationship is one in which changes in the circuit constants of the sensor sheet 1 can be detected, and an inappropriate positional relationship is one in which such changes cannot be detected. However, the detection unit 23 may indicate the degree of appropriateness with a level value rather than making a binary determination of whether the positional relationship is appropriate or not. The specific method for detecting the positional relationship is not limited in any way.

[0054] The operation unit 26 is configured to be operable by the user. For example, the operation unit 26 can be implemented as one or more push buttons. However, it is sufficient that user operations on the operation unit 26 can be detected by the control unit 22, and the number and specific configuration of the operation unit 26 are not limited in any way. For example, the operation unit 26 may be used as an operation button to instruct the start of wetness detection, or as an operation button to instruct the switching of the operating mode of the control unit 22. Examples of operating modes of the control unit 22 include an operating mode that causes the detection unit 23 to determine the positional relationship between the power supply coil 201 and the power receiving coil 11, and an operating mode that performs wetness detection. These operating modes will be described later.

[0055] The transmission processing unit 24 processes transmissions to external computers. The transmission processing unit 24 executes short-range wireless communication methods such as wireless LAN (Local Area Network), Bluetooth®, and infrared communication. The transmission processing unit 24 transmits information to the external computer that allows for the detection of changes in the circuit constants of the circuit section of the sensor sheet 1 based on the detection by the detection unit 23, using this communication method. The information transmitted by the transmission processing unit 24 only needs to be information that allows for the detection of changes in the circuit constants, and its specific content is not limited. For example, if the detection unit 23 derives the circuit constants (impedance, etc.) of the sensor sheet 1, the transmission processing unit 24 may transmit those circuit constants directly to the external computer. Also, if the detection unit 23 measures the electrical characteristic values ​​of the resonant circuit, the transmission processing unit 24 may transmit those electrical characteristic values ​​to the external computer. Furthermore, if the detection unit 23 is configured to detect stepwise changes in the circuit constants, the transmission processing unit 24 can also transmit information to the external computer indicating that the circuit constants have changed. The information transmitted in this case can be called wet detection information.

[0056] The notification unit 25 is a notification means that notifies the positional relationship between the power supply coil 201 detected by the detection unit 23 and the power receiving coil 11 of the sensor sheet 1. For example, the notification unit 25 includes a light-emitting element such as an LED (Light Emitting Diode), and emits light from the light-emitting element according to whether the positional relationship is appropriate or not, as determined by the detection unit 23. The notification unit 25 emits light from the light-emitting element when the positional relationship is appropriate, and does not emit light from the light-emitting element when it is not appropriate. It is also possible to change the color of the emitted light according to whether the positional relationship is appropriate or not, or the degree of appropriateness. When replacing the sensor sheet 1 along with the diaper 50, the transmission unit 2 is attached to the new diaper 50 to which the replaced sensor sheet 1 is attached. Even during such replacements, the notification unit 25 allows the transmission unit 2 to be easily attached to the correct position (a position where wetness can be detected).

[0057] The control unit 22 includes a processor such as a CPU (Central Processing Unit), MPU (Micro Processor Unit), or MCU (Micro Controller Unit), memory such as RAM (Random Access Memory) or ROM (Read Only Memory), and an input / output interface unit. The control unit 22 is powered by electricity supplied from the battery, and various controls are performed by reading and executing programs stored in memory using the processor. The detection unit 23 described above may be included in the control unit 22.

[0058] The control unit 22 controls the drive of the switching circuit 205 described above. Furthermore, the control unit 22 executes an operation mode in which the detection unit 23 determines the positional relationship between the power supply coil 201 and the power receiving coil 11 (hereinafter referred to as the position determination mode), an operation mode in which wetness detection is performed (hereinafter referred to as the wetness detection mode), and so on. In the wetness detection mode, the control unit 22 first instructs the detection unit 23 to maintain the above-mentioned reference value, and then executes the normal wetness detection process. In the wetness detection process, the control unit 22 causes the detection unit 23 to detect changes in circuit constants and transmits the detection result to the transmission processing unit 24.

[0059] For example, when the control unit 22 detects that the operation unit 26 has been pressed, it executes a position determination mode and instructs the detection unit 23 to determine the positional relationship. If the detection unit 23 determines that the positional relationship is correct, the control unit 22 instructs the detection unit 23 to maintain the aforementioned reference value, and thereafter executes the wetness detection mode. If the operation unit 26 that triggers the execution of the position determination mode and the operation unit 26 that triggers the execution of the wetness detection mode are provided separately, then the respective operation modes can be executed by detecting the pressing operation of each operation unit 26. In addition, a separate operation unit 26 corresponding to the maintenance of the reference value may be provided. Furthermore, the operation mode executed may be switched depending on how the operation unit 26 is operated (long press, short press, etc.).

[0060] [Second Embodiment] In the wetness detection sensor kit according to the first embodiment, the sensor sheet and the transmitting unit were used in a state where they were completely separated, but in the wetness detection sensor kit according to the second embodiment, the sensor sheet and the transmitting unit are used in a state where they are electrically connected. Furthermore, in the second embodiment, an example is shown in which the sensor sheet is formed as part of an absorbent article, and the wetness detection sensor kit according to the second embodiment consists of an absorbent article including the sensor sheet and a transmitting unit. The following description of the wetness detection sensor kit according to the second embodiment will focus on aspects that differ from the first embodiment, and explanations of aspects that are the same as the first embodiment will be omitted as appropriate.

[0061] <Absorbent articles including wetness sensor sheets> Figure 5 is a schematic diagram showing an example of attaching the transmission unit 2 to an absorbent article including the wet sensor sheet (this sensor sheet) 1 according to the second embodiment. The absorbent material shown in Figure 5 is a diaper 50, and the sensor sheet 1 is formed as part of the diaper 50. The diaper 50 is equipped with a connector 60 for detachably connecting the transmitting unit 2.

[0062] The connector 60 is provided to protrude from the outside of the ventral or dorsal portion 52 of the absorbent article. In the example shown in Figure 5, the connector 60 has two protrusions that protrude from the outside of the ventral portion 51 of the diaper 50. The transmitting unit 2 has fastening means (not shown) on one side of the outer case that houses the circuit board, power supply, etc., and is detachably attached to the outer surface of the ventral portion 51 of the diaper 50 by connecting the fastening means and the connector 60. The fastening means of the transmitting unit 2 may have a recess into which the protrusions of the connector 60 can be fitted. For example, the fastening means of the transmitting unit 2 may have a structure in which the protrusions of the connector 60 are fitted into the recess and locked by the spring mechanism, such as a snap-type fastening. However, the shape of the connector 60 is not limited to the example shown in Figure 5, and any shape that can connect (fasten) the transmitting unit 2 to the diaper 50 is acceptable.

[0063] Furthermore, the connector 60 has an internal wiring section that electrically connects the transmitting unit 2 to the circuit section of the sensor sheet 1 when the transmitting unit 2 is connected. The electrical connection configuration between the transmitting unit 2 and the circuit section of the sensor sheet 1 will be described later.

[0064] Figure 6 shows the side of the wet sensor sheet (this sensor sheet) 1 according to the second embodiment on which the circuit section is provided. The wet sensor sheet 1 according to the second embodiment differs from the first embodiment only in that the power receiving coil 11 is replaced with two power receiving terminals 18. The power receiving terminal 18 may consist only of the end of the wiring connected to the sensor circuit section 12, or it may consist of the end and a conductive coating optionally laminated together. The power receiving terminal 18 is connected to the wiring section within the connector 60 described above, and is electrically connected to the output terminal of the transmitting unit 2 when the connector 60 is connected to the transmitting unit 2.

[0065] <Transmission Unit> As described above, the transmission unit 2 according to the second embodiment differs from the first embodiment in its connection configuration with the diaper 50, and also in the configuration of the power supply circuit 20. In the second embodiment, the power supply circuit 20 may have an output terminal (not shown) instead of the power supply coil 201, resonant capacitor 202, and switching circuit 205. In the second embodiment, the power supply circuit 20 outputs DC power supplied from the battery 21 to the circuit section of the sensor sheet 1 via this output terminal. The DC power output from the output terminal is transmitted to the power receiving terminal 18 of the sensor sheet 1 via the wiring section in the connector 60.

[0066] In this second embodiment, although the sensor sheet 1 and the transmitting unit 2 are formed separately, they are configured to be electrically connected using the connector 60. In this way, the mounting position of the transmitting unit 2 is clearly defined, making it easy to install. Furthermore, once the transmitting unit 2 is installed, it is electrically connected to the sensor sheet 1, allowing the transmitting unit 2 to reliably detect changes in the circuit constants of the sensor sheet 1.

[0067] [Differentiation] The details of each embodiment described above are merely examples and may be partially modified as appropriate. For example, the circuit section of the sensor sheet 1 described above may further include a resonant capacitor connected in parallel with the power receiving coil 11. By configuring the resonant circuit formed by the power receiving coil 11 and its resonant capacitor to have the same resonant frequency as the resonant circuit included in the power supply circuit 20 of the transmitting unit 2, wireless power supply using magnetic field resonance becomes possible, and power transmission can be performed even if the distance between the power receiving coil 11 and the power supply coil 201 is somewhat far, or if there is some misalignment of the coil axes. As a result, the restrictions on the relationship between the mounting position of the sensor sheet 1 and the transmitting unit 2 can be relaxed.

[0068] Furthermore, in the embodiments described above, examples were shown in which the sensor sheet 1 is attached to or formed as part of the diaper 50. However, the sensor sheet 1 may also be attached to or formed as part of a urine absorption pad worn together with the diaper 50. In this case, the transmitting unit 2 may be attached to the outside of the urine absorption pad, i.e., the side facing the diaper 50, or it may be attached to the outside of the diaper 50, as in the embodiments described above.

[0069] Furthermore, in the second embodiment described above, the power supply circuit 20 of the transmitting unit 2 supplied DC power to the circuit section of the sensor sheet 1, but it may also be configured to supply AC power. In this case, the power supply circuit 20 has a power supply coil 201, a resonant capacitor 202, and a switching circuit 205, similar to the first embodiment, and may further include a pair of output terminals connected to both ends of the power supply coil 201.

[0070] Furthermore, the aforementioned transmission unit 2 does not necessarily have to have a notification unit 25 and an operation unit 26. In this case, the functions of the notification unit 25 and the operation unit 26 may be implemented by an external computer. For example, the external computer may display operation buttons on the display unit to instruct the start of wet detection, operation buttons to instruct the determination of the positional relationship between the power supply coil 201 and the power receiving coil 11, or operation buttons to instruct the holding of a reference value for detecting changes in circuit constants, and in response to user operations on these operation buttons, the external computer may wirelessly notify the transmission unit 2 of the corresponding instructions. Furthermore, the transmission unit 2 may be configured to have a notification unit 25 and an operation unit 26, while also being capable of implementing the above-described wireless communication method with an external computer.

[0071] Furthermore, in each of the embodiments described above, the detection unit 23 of the transmitting unit 2 detected a change in the circuit constants of the sensor sheet 1 or a change in the electrical characteristics of the resonant circuit connected thereto. However, an external computer may be configured to detect the change in the circuit constants of the sensor sheet 1. In this case, the detection unit 23 may measure a parameter value that enables the detection of the change in the circuit constants (for example, the electrical characteristic value of the resonant circuit of the power supply circuit 20), and the transmitting processing unit 24 may transmit this parameter value to the external computer as information that enables the detection of the change in the circuit constants. In this case, the transmitting processing unit 24 may transmit a reference value for detecting the change in the circuit constants of the circuit section measured by the detection unit 23 to the external computer, and the external computer may detect the change in the circuit constants by comparing the reference value with the parameter values ​​that are received sequentially.

[0072] Furthermore, the transmitting unit 2 may also be equipped with an odor sensor. In this case, the transmitting unit 2 can detect wetness or urine volume by changes in circuit constants, and can distinguish between urination and defecation based on detection signals from the odor sensor. Furthermore, the sensor sheet 1 may also be equipped with a temperature sensor. In this case, the transmitting unit 2 can detect temperature changes based on the detection signal from the temperature sensor and infer whether or not there is wetness or urination from the temperature changes.

[0073] Some or all of the above embodiments and modifications may also be specified as follows; however, the above embodiments and modifications are not limited to those described below.

[0074] <1> A wet sensor sheet is detachable from a transmitting unit configured to transmit to an external computer, and is formed as part of an absorbent article or is formed to be attachable to an absorbent article, Permeable sheet and A circuit section provided in the permeable sheet and supplied with power from the transmitting unit, Equipped with, The circuit section includes a power receiving section that receives power from the transmitting unit, and a sensor circuit section that is electrically connected to the power receiving section and printed at a position that comes into contact with urination. The sensor circuit is configured such that the circuit constants change in stages according to the amount of urine excreted. Wetness sensor sheet. <2> The sensor circuit section is printed with conductive ink and includes a plurality of wiring pattern sections arranged in multiple stages to form parallel circuits with respect to the power receiving section, and a plurality of specific circuit elements provided in each wiring pattern section. Each of the aforementioned plurality of specific circuit elements short-circuits or disconnects the wiring pattern portion upon contact with urination. the above <1> The wetness sensor sheet described above. <3> The plurality of wiring pattern sections are arranged in multiple rows in a first direction from the crotch area of ​​the wearer toward the ventral or dorsal side when the absorbent article is worn. The aforementioned multiple specific circuit elements are also arranged in multiple stages in the first direction. the above <2> The wetness sensor sheet described above. <4> Each of the aforementioned plurality of specific circuit elements is distributed in a second direction intersecting the first direction. the above <3> The wetness sensor sheet described above. <5> The plurality of specific circuit elements, each included in the plurality of specific circuit elements adjacent to each other in the first direction, are each provided on opposite sides of the center of the second direction in the wet sensor sheet, in the second direction. the above <4> The wetness sensor sheet described above. <6> The plurality of wiring pattern sections include one or more specific wiring pattern sections that do not have the specific circuit element and maintain a conductive state with the power receiving section. the above <2> From the above <5> A wetness sensor sheet described in one of the following terms. <7> The transmitting unit has a power supply coil, The power receiving unit is a power receiving coil that is supplied with power from the power supply coil using a magnetic field, The power receiving coil is provided on the permeable sheet such that the coil's central axis is perpendicular to the sheet surface of the permeable sheet. the above <1> From the above <6> A wetness sensor sheet described in one of the following terms. <8> the above <7> The wetness sensor sheet described above, The transmitting unit, which is separated from the wet sensor sheet, Equipped with, The transmitting unit includes a power supply, a power supply coil that receives power from the power supply, a resonant capacitor that forms a resonant circuit together with the power supply coil, a detection unit that measures parameter values ​​that enable the detection of changes in the circuit constants of the circuit portion of the wet sensor sheet, and a transmitting processing unit that transmits information that enables the detection of changes in the circuit constants of the circuit portion to the external computer based on the detection by the detection unit. Wetness detection sensor kit. <9> The transmitting unit further includes a position detection unit that detects the positional relationship between the power supply coil and the power receiving coil of the wet sensor sheet, and a notification unit that notifies the positional relationship detected by the position detection unit. the above <8> The wetness detection sensor kit described above. <10> The transmission unit further includes an operating section that can be operated by the user, The detection unit, triggered by the operation of the operation unit, holds parameter values ​​for detecting changes in the circuit constants of the circuit section as reference values. the above <8> or the above <9> The wetness detection sensor kit described above. <11> the above <1> From the above <6> An absorbent article containing a wet sensor sheet as described in any one of the following, The aforementioned transmitting unit is equipped with a connector for detachably connecting the units. The power receiving unit is a power receiving terminal that receives power from the transmitting unit, The connector includes a wiring section that electrically connects the output terminal of the transmitting unit and the power receiving terminal when the transmitting unit is connected. Absorbent material. [Explanation of Symbols]

[0075] 1. Wet sensor sheet (this sensor sheet) 2 Transmitting Units 10 Permeable Sheet 11. Receiving coil 12 Sensor circuit section 13 Wiring pattern section 14. Specific wiring pattern section 15 Specific circuit elements 17 Conductive wiring pattern section 18 Power receiving terminal 20 Power supply circuit 21 batteries 22 Control Unit 23 Detection unit 24. Transmission Processing Unit 25 Hochi Department 26 Control section 50 diapers 51 Ventral part 52 Dorsal part 53 Connecting part 54 Fastening Tape 55 Absorbent 57 Three-dimensional gathers 60 connectors 201 Power supply coil 202 Resonant Capacitor 205 Switching Circuit

Claims

1. A wet sensor sheet is detachable from a transmitting unit configured to transmit to an external computer, and is formed as part of an absorbent article or is formed to be attachable to an absorbent article, Permeable sheet and A circuit section provided in the permeable sheet and supplied with power from the transmitting unit, Equipped with, The circuit section includes a power receiving section that receives power from the transmitting unit, and a sensor circuit section that is electrically connected to the power receiving section and printed at a position that comes into contact with urination. The sensor circuit is configured such that the circuit constants change in stages according to the amount of urine excreted. Wetness sensor sheet.

2. The sensor circuit section includes a plurality of wiring pattern sections, each printed with conductive ink and arranged in multiple stages to form parallel circuits with respect to the power receiving section, and a plurality of specific circuit elements provided in each wiring pattern section. Each of the aforementioned plurality of specific circuit elements short-circuits or disconnects the wiring pattern portion upon contact with urination. The wet sensor sheet according to claim 1.

3. The plurality of wiring pattern sections are arranged in multiple rows in a first direction from the crotch area of ​​the wearer toward the ventral or dorsal side when the absorbent article is worn. The aforementioned multiple specific circuit elements are also arranged in multiple stages in the first direction. The wet sensor sheet according to claim 2.

4. Each of the aforementioned plurality of specific circuit elements is distributed in a second direction intersecting the first direction. The wet sensor sheet according to claim 3.

5. The plurality of specific circuit elements, each included in the plurality of specific circuit elements adjacent to each other in the first direction, are each provided on opposite sides of the center of the second direction in the wet sensor sheet, in the second direction. The wet sensor sheet according to claim 4.

6. The plurality of wiring pattern sections include one or more specific wiring pattern sections that do not have the specific circuit element and maintain a conductive state with the power receiving section. A wet sensor sheet according to any one of claims 2 to 5.

7. The transmitting unit has a power supply coil, The power receiving unit is a power receiving coil that is supplied with power from the power supply coil using a magnetic field, The power receiving coil is provided on the permeable sheet such that the coil's central axis is perpendicular to the sheet surface of the permeable sheet. A wet sensor sheet according to any one of claims 1 to 5.

8. The wet sensor sheet according to claim 7, The transmitting unit, which is separated from the wet sensor sheet, Equipped with, The transmitting unit includes a power supply, a power supply coil that receives power from the power supply, a resonant capacitor that forms a resonant circuit together with the power supply coil, a detection unit that measures parameter values ​​that enable the detection of changes in the circuit constants of the circuit portion of the wet sensor sheet, and a transmitting processing unit that transmits information that enables the detection of changes in the circuit constants of the circuit portion to the external computer based on the detection by the detection unit. Wetness detection sensor kit.

9. The transmitting unit further includes a position detection unit that detects the positional relationship between the power supply coil and the power receiving coil of the wet sensor sheet, and a notification unit that notifies the positional relationship detected by the position detection unit. The wetness detection sensor kit according to claim 8.

10. The transmission unit further includes an operating section that can be operated by the user, The detection unit, triggered by the operation of the operation unit, holds parameter values ​​for detecting changes in the circuit constants of the circuit section as reference values. The wetness detection sensor kit according to claim 8.

11. An absorbent article comprising a wet sensor sheet according to any one of claims 1 to 5, The aforementioned transmitting unit is equipped with a connector for detachably connecting the units. The power receiving unit is a power receiving terminal that receives power from the transmitting unit, The connector includes a wiring section that electrically connects the output terminal of the transmitting unit and the power receiving terminal when the transmitting unit is connected. Absorbent material.

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