JP6806294B2 - Liquid detection sensor and liquid detection device - Google Patents

Description

The present invention relates to a liquid detection sensor using a wireless tag that is attached to, for example, a diaper and detects a state such as urination due to incontinence, and a liquid detection device that detects the state of the liquid detection sensor.

With the progress of aging in recent years, the number of care recipients who need diapers is increasing. In particular, with the onset of dementia and the like, the situation in which the care recipient cannot convey the urinary intention to the caregiver is increasing due to reasons such as the inability to achieve satisfactory communication with the caregiver. Under such circumstances, it is necessary to change the diaper at a predetermined time or at regular intervals.
However, the care recipient may incontinence immediately after changing the diaper, and if time elapses in this state, the odor due to urination or the like may fill up, or the care recipient may develop so-called diaper rash while this overlaps. Sometimes it happens.

In addition, since the caregiver cannot grasp the condition if the diaper is opened, the diaper of the care recipient who is not incontinent must be opened and put on again.
Therefore, unnecessary labor is generated for the caregiver, and further, the sleep of the care recipient is disturbed. For this reason, an incontinence detection sensor that can detect incontinence without the caregiver opening the diaper has been proposed.

As a conventional incontinence detection sensor, for example, as disclosed in Patent Document 1, a sensor using a resonance circuit having resonance characteristics for a specific frequency by combining a coil and a capacitor has been proposed.
As this resonance circuit, a metal such as copper or aluminum produced by etching is used, and whether or not the dielectric arranged between the pair of electrodes forming the capacitor has absorbed, for example, urine. Is configured to detect.

That is, a configuration is adopted in which the detection device (reader) side detects that the resonance frequency decreases due to the increase in the relative permittivity due to the dielectric absorbing water in urine.
The feature of Patent Document 1 is that the incontinence detection sensor can be reused by washing it with water and drying it.

Further, as a conventional incontinence detection sensor, a sensor using a passive RFID tag is disclosed in Patent Document 2. An IC chip is mounted on the RFID tag, and a configuration is adopted in which the detection device (reader) detects that the inductance of the antenna coil of the tag fluctuates due to, for example, urine adhering to the RFID tag.

In addition, in Patent Document 2, in order to use this RFID tag to monitor multiple incontinences of a care recipient over time, urine that has once penetrated and adhered to the RFID tag is collected from the tag. It also discloses the form of a package that wraps an RFID tag devised so that it can be discharged immediately.

The incontinence detection sensor disclosed in Patent Document 1 described above has a technical problem that the stability of the frequency change is poor because the change in the dielectric constant due to the moisture content of the dielectric is used. Further, since all of the incontinence detection sensors disclosed in Patent Document 2 can be reused, the unit price as a sensor is expensive by mounting an IC chip. Therefore, the sensor cannot be thrown away each time and must be reused inevitably.

Therefore, the Applicant applied the printed electronics manufacturing technology, which has been attracting attention in recent years, to a liquid in which a resonance circuit including a coil and a capacitor is mounted on a flexible film by coating or printing with a conductive ink. The detection sensor has been proposed earlier, and this is disclosed in Patent Document 3.
According to this, it is possible to provide a liquid detection sensor that is much cheaper than a sensor equipped with an IC chip, and by attaching this liquid detection sensor to, for example, a diaper, it is suitably used as an incontinence detection sensor. Moreover, it is possible to adopt an operation mode in which the product is disposable each time.

Japanese Unexamined Patent Publication No. 2004-85277 Japanese Unexamined Patent Publication No. 2011-67619 JP-A-2015-114213

By the way, the liquid detection sensor disclosed in Patent Document 3 for which the applicant has filed a patent application earlier receives water such as urine due to incontinence by attaching it to a diaper, and a printed capacitor and coil conductor. We are paying attention to the fact that the resonance circuit is broken. That is, the state of incontinence is detected by making the resonance circuit of the sensor inoperable.

However, since the resonance circuit described above can be formed in a relatively small area on the film substrate, when the liquid detection sensor is attached to a diaper, it is not always the case that water such as urine comes into contact with the main part of the sensor. Not exclusively. In addition, there is a problem that the reliability as a sensor is lacking in practical use, such as the difference between men and women in the place where the diaper gets wet.

Therefore, in order to improve the detection accuracy of incontinence, it is conceivable to form a large area of, for example, the conductor portion of the coil in the resonance circuit. However, in this case, the antenna (coil conductor part) when attached to the diaper is greatly affected by bending, etc., causing a deviation in the resonance frequency, and the detection function (information information) on the reader side that acquires information from the sensor. Another problem is that the reading function) is reduced.

The present invention has been made based on the above-mentioned practical problems and technical viewpoints, and is a routing capable of covering a large area, for example, in order to be attached to a diaper to improve the incontinence detection function. An object of the present invention is to provide a liquid detection sensor having improved reliability as a sensor by providing wiring.
In addition, the reader that acquires information from the liquid detection sensor can also verify the existence of the care recipient on the bed (presence of diapers) and whether or not it is incontinent, and the caregiver and the care recipient can also be verified. In both cases, it is an object to provide a liquid detection device that is less burdensome to handle.

The basic configuration of the liquid detection sensor according to the present invention made to achieve the above-mentioned problems is that a flexible sheet-like film is used as a base material, and a capacitor and a coil conductor are formed on the base material surface. A resonance circuit is formed in which the wiring connecting the capacitor and the coil conductor, which are arranged adjacent to each other, is laid on the surface of the base material for a long time by coating or printing with conductive ink. Further, between the base material and the routing wiring, a wiring breaking layer that cuts the routing wiring by expanding with moisture or by dissolving with moisture is arranged.

Then, according to a more preferable configuration of the liquid detection sensor according to the present invention, a capacitor and a coil conductor are formed on the surface of the base material using a flexible sheet-like film as a base material, and are arranged adjacent to each other. A resonance circuit is formed by applying or printing two wires connecting the capacitor and the coil conductor on the base material surface together with the capacitor and the coil conductor using conductive ink. Is formed , and one of the two wirings is a routing wiring that connects the first electrode forming the capacitor and one end of the coil conductor formed in a spiral shape. The other of the wirings is a bypass wire connecting the second electrode forming the capacitor and the other end of the coil conductor, and the length dimension of the routing wiring on the substrate surface is a rectangular coil conductor. It is formed larger than the length of the long side of the conductor or the diameter of the circular coil conductor, and it expands with moisture or dissolves with moisture between the base material and the routing wiring. As a result, a wiring destruction layer that cuts the routing wiring is arranged, and the routing wiring is formed by a single conductor wiring that connects the outward wiring and the return wiring at the folded-back tip portion, and the outward wiring and the return wiring are formed. The wires are arranged adjacent to each other on the substrate surface .

Then, in the liquid detection sensor according to the present invention, the wiring breaking layer that expands or dissolves, preferably containing water, intersects the routing wiring in the longitudinal direction at a plurality of locations along the longitudinal direction of the routing wiring. It is arranged in this way.

Further, sodium polyacrylate is preferably used for the wiring breaking layer that expands with water, and polyacrylic acid having a relatively low degree of polymerization is preferably used for the wiring breaking layer that dissolves with water. , Polyvinyl alcohol is used.

On the other hand, one preferable form of the liquid detection device according to the present invention made to achieve the above-mentioned problems is that the state of the liquid detection sensor is non-contacted with the above-mentioned liquid detection sensor attached to an inspection target. A liquid detection device for detecting, a detection radio wave emitting means for sweeping and emitting a detection radio wave frequency from the liquid detection sensor, and the detection radio wave emitting means when the resonance frequency of the liquid detection sensor is matched. By detecting the change in the transmission side current in the above, a discriminating means for discriminating the wet or dry state due to the liquid in the inspection target is provided.

Further, in another preferred embodiment of the liquid detection device according to the present invention, the above-mentioned liquid detection sensor is attached to an inspection target as a first liquid detection sensor, and a resonance frequency different from the resonance frequency of the first liquid detection sensor is set. A liquid that non-contactly detects the states of the first liquid detection sensor and the second liquid detection sensor with a second liquid detection sensor that is provided with a resonance circuit and whose resonance circuit is not destroyed by moisture. A detection device that sweeps the frequency of the detection radio wave and emits the first liquid detection sensor and the second liquid detection sensor, and the first liquid detection sensor and the second liquid detection sensor. By detecting changes in the transmitting side current in the detected radio wave emitting means when the resonance frequency of the above is matched, there is provided with a discriminating means for discriminating the presence or absence of the inspection target and the wet or dry state due to the liquid of the inspection target. Be done.

According to the liquid detection sensor according to the present invention described above, a capacitor and a coil conductor are formed on a flexible sheet-like film base material, and the wiring connecting both the capacitor and the coil conductor is based on the film with conductive ink. A long-running resonant circuit is formed on the material. Then, a configuration is adopted in which a wiring breaking layer that expands or dissolves by containing water is arranged between the base material and the routing wiring.
According to this configuration, since the routing wiring covering a wide area can be provided, it is possible to provide a liquid detection sensor having improved reliability of liquid detection without causing a deviation in the resonance frequency.

On the other hand, by attaching the liquid detection sensor to a diaper to be inspected, the liquid detection sensor can be used as an incontinence detection sensor.
According to the preferred first mode of the liquid detection device, whether the diaper is in a dry state or a wet state depending on the presence or absence of a change in the current on the transmitting side that transmits the detection radio wave to the liquid detection sensor attached to the diaper. Can be reliably determined.

Further, according to a preferred second mode of the liquid detection device, the above-mentioned liquid detection sensor in which the wiring is broken by the liquid is used as the first liquid detection sensor, and a resonance circuit having a resonance frequency different from that of the first liquid detection sensor is provided. In preparation, by attaching a second liquid detection sensor whose resonance circuit is not destroyed by moisture to the diaper to be inspected, the presence or absence of the diaper to be inspected (determination of whether the care recipient is on the bed) and the diaper Can be reliably determined whether is in a dry state or a wet state.

It is a schematic diagram explaining the example which used this invention as an incontinence detection device in a care facility. It is a schematic diagram explaining the arrangement relation of the liquid detection sensor attached to the diaper of a care recipient, and the antenna on the reader side. It is a block diagram which showed the structure of the liquid detection device which consists of a liquid detection sensor and a reader. It is a schematic diagram which showed an example of the film formation order by printing of a liquid detection sensor. It is a perspective view of the liquid detection sensor obtained by the film formation order shown in FIG. It is a perspective view which showed the other example of the liquid detection sensor. It is a graph which shows the detection state of the liquid detection sensor on the reader side in 1st Embodiment. It is a graph which shows the detection state of the liquid detection sensor on the reader side in the 2nd Embodiment. It is a flowchart explaining the determination operation on the reader side in 2nd Embodiment.

The liquid detection sensor and the liquid detection device according to the present invention will be described by taking as an example a case where the liquid detection sensor and the liquid detection device are used as an incontinence detection device in a nursing facility.
As shown in FIG. 1, a leader 11 is individually installed for each bed in the bed 1 of the care recipient in the nursing facility, and an antenna 12 extending from the leader 11 is provided between the bed 1 and the mattress on the bed, for example. Or, it is attached to the back side of the bed 1.

As shown in FIG. 2, a diaper 3 is attached to the care recipient 2 on the bed 1, and an incontinence detection sensor 21 (hereinafter, also simply referred to as a detection sensor) as a liquid detection sensor is housed in the diaper 3. ing.
The detection sensor 21 is equipped with a resonance circuit formed by the capacitor C1 and the coil L1, which will be described in detail later. Then, depending on whether or not this resonance circuit responds to the detection radio wave emitted from the antenna 12 connected to the reader 11, the state of the diaper 3 of the care recipient 2, that is, whether it is in a dry state or a wet state is described. It acts to detect in the reader 11.

When the reader 11 detects that the diaper 3 of the care recipient 2 is in a wet state, the reader 11 sends the reader 11 to the host computer 5 installed in the monitoring center of the care facility as shown in FIG. On the other hand, the information is transmitted together with the bed address code by using, for example, a wireless LAN. Reference numeral 6 shown in FIG. 1 indicates a wireless LAN transmission / reception device installed on the monitoring center side.
Further, the host computer 5 operates so as to transmit information to the portable receiving device 8 possessed by the caregiver 7 by using the transmitting / receiving device 6 of the wireless LAN according to the set program.

FIG. 3 is a block diagram showing the overall configuration of the incontinence detection device 16 including the detection sensor 21 and the reader 11.
The detection sensor 21 described above is mounted in the diaper 3 worn on the care recipient, and the antenna 12 connected to the reader 11 is arranged on the bed of the care recipient as described above. The reader 11 is provided with a detection radio wave transmission device 13 for transmitting a detection radio wave to the antenna 12, and a discrimination device 14 connected to the detection radio wave transmission device 13. The discrimination device 14 discriminates the state of the detection sensor 21 mounted on the diaper 3 by detecting a change in the transmission side current in the detection radio wave transmission device 13, and a detailed description thereof will be described later.

4 and 5 show a first example of the liquid detection sensor 21 used in the present invention.
The liquid detection sensor 21 uses a flexible sheet-like film as a base material, and uses conductive ink on the base material to connect the capacitor C1 and the coil L1 and both to form a resonance circuit. Wiring is formed.
Further, in this embodiment, the capacitor C1 is expanded by containing moisture so as to intersect the dielectric and the routing wiring together with the conductive ink forming the conductor, or is dissolved by containing moisture. Then, a wiring breakage layer that cuts the routing wiring is formed.

Then, the film-forming materials of the conductive ink, the dielectric layer, and the wiring breaking layer described above are dissolved in an appropriate solvent and made into a liquid by gelling or the like, so that a coating method, screen printing, or printing such as an inkjet can be performed. The technique can be used to form a film on the substrate in any shape.
Further, since different materials can be laminated to form a structure, various devices can be formed in a plane or in a thickness direction in addition to the LC resonance circuit described below.

FIG. 4A shows an example in which the first electrode (lower electrode) 23 of the capacitor C1 is formed by printing on the film base material 22 using conductive ink. In this example, the lower electrode 23 of the capacitor C1 is formed in a comb-teeth shape. Then, the conductor connecting the comb-shaped lower electrode 23 is extended toward the center of the film base material 22, and the conductor end portion 23a is connected to the routing wiring described later.
Further, at the same time as the film formation of the first electrode (lower electrode) 23, the bypass line 24 is also formed by printing with the conductive ink. The bypass wire 24 functions to connect the upper electrode of the capacitor C1 to be described later and the inner end of the coil L1.

FIG. 4B shows a pattern of the dielectric layer 25 and the wiring breakage layer 26 of the capacitor C1 printed on the first electrode (lower electrode) 23 of the capacitor C1. Note that in FIG. 4B, the lower electrode 23 and the bypass line 24 of the capacitor C1 printed earlier are not shown because the drawing becomes complicated.

The wiring breakage layers 26 that expand or dissolve by containing water are formed in strips and are arranged in a rectangular shape so as to occupy a large area in the upper half of the film base material 22.
Each of these strip-shaped film-deposited wiring breakage layers 26 is arranged so as to intersect the routing wiring described later, which is overlaid on the wiring breakage layer 26.
Further, the insulating layer 27 is formed so as to cover a part of the bypass wire 24 described above. The insulating layer 27 functions to prevent the bypass wire 24 and the coil conductor described later from being short-circuited.
The dielectric layer 25, the wiring breakage layer 26, and the insulating layer 27 may be formed of the same material by printing once, or may be printed by printing another material twice or more.

FIG. 4C shows a second electrode (upper electrode) 28 of the capacitor C1 formed on the upper surface of the dielectric layer 25, and a spiral shape connected to the upper electrode 28 via the bypass wire 24. The pattern of the routing wiring 30 formed on the upper surface of the coil conductor 29 and the wiring breaking layer 26 connected in series to the coil conductor 29 and arranged in a strip shape is shown. ..

By forming a pattern of the second electrode (upper electrode) 28 of the capacitor C1 shown in FIG. 4C, the spiral coil conductor 29, and the routing wiring 30 by printing conductive ink, the lower electrode described above is formed. A dielectric layer 25 is inserted between the 23 and the upper electrode 28 to form a capacitor C1. Further, the capacitor C1 and the coil conductor 29 are connected by a routing wire 30 to form a series resonance circuit. As a result, the liquid detection sensor 21 having the configuration shown in the perspective view of FIG. 5 can be obtained.

As shown in FIG. 5, in the liquid detection sensor 21, the routing wiring 30 is a loop formed in a rectangular shape and a connection arranged in parallel with each other for connecting the loop to the capacitor C1 and the coil L1. It is composed of lines 30a and 30b.
Then, the length dimension of the routing wiring 30 on the base material 22 surface, that is, in the example shown in FIG. 5, the total length including the rectangular loop of the routing wiring 30 and the connecting wires 30a and 30b. The vertical dimension is formed larger than the length dimension of the long side of the rectangular coil conductor 29. The coil conductor 29 shown in FIG. 5 is formed to be substantially square, and in this case, the length dimension of the long side of the coil conductor 29 is said to be the length dimension of one side of the square.

By increasing the length dimension of the routing wiring 30 in this way, the liquid detection area can be substantially expanded, and thus the detection range as the liquid detection sensor is expanded. Therefore, it can contribute to the improvement of reliability as a liquid detection sensor.
Moreover, the length of the routing wiring 30 has some influence on the decrease in the Q value of the resonance circuit described later, but does not affect the change in the resonance frequency.
The coil conductor 29 shown in FIG. 5 is formed to be substantially square as described above, but the outer shape of the coil conductor 29 can be formed into, for example, a circular shape. In this case, it is desirable that the length dimension of the routing wire is formed larger than the diameter of the circular coil conductor.

In the detection sensor 21 provided with the routing wiring 30 for connecting the capacitor C1 and the coil L1, the film is formed so that the wiring breaking layer 26 intersects the routing wiring 30 between the film base material 22 and the routing wiring 30. Has been done.
Then, in one preferable form, an expansion material layer that expands by containing water is used as the wiring breakage layer 26. According to the detection sensor 21 using this expansion material layer, when moisture invades the detection sensor 21, the expansion material layer as the wiring destruction layer 26 expands including moisture, and the wiring destruction layer (due to this expansion action) It acts to cut the routing wiring 30 formed on the expansion material layer) 26.

Further, in another preferable form, a dissolution material layer that contains and dissolves water is used as the wiring breakage layer 26. According to the detection sensor 21 using this dissolution material layer, when moisture invades the detection sensor 21, the dissolution material layer as the wiring breakage layer 26 contains moisture and dissolves. As a result, the routing wiring 30 formed on the wiring breaking layer (dissolved material layer) 26 is effectively cut by melting the dissolved material layer.
By utilizing the wiring destruction layer 26 that expands or dissolves due to the moisture, the LC resonance circuit of the detection sensor 21 stops functioning and does not react to the detection radio wave projected from the reader 11.

As the film base material 22 constituting the liquid detection sensor 21 described above, PET (polyethylene terephthalate) can be preferably used. This PET has excellent adhesion of conductive ink, is easily available at low cost, and can be suitably used because it has relatively good moldability.
Further, as the conductive ink, a silver paste, a silver copper nanopaste or the like having conductivity at a low temperature is used.

Further, in this embodiment, the same material can be used for the dielectric layer 25, the wiring breakage layer 26, and the insulating layer 27 constituting the capacitor C1, and the above-mentioned expansion material is used for these. For example, sodium polyacrylate can be preferably used. According to the super absorbent polymer using this sodium polyacrylate, it has a property of expanding to several tens of times its own weight by water absorption, and therefore, the water absorption ensures that the routing wiring 30 formed of conductive ink is secured. The function of the LC resonant circuit can be stopped.

When the above-mentioned dissolved material is used for the wiring breaking layer 26, low-polymerization polyacrylic acid, for example, polyacrylic acid having a molecular weight of 5000 or 25000, PVA (polyvinyl alcohol), starch, or the like can also be used. it can. These are easily dissolved in water, and therefore, water absorption can surely break the routing wiring 30 formed of the conductive ink and stop the function of the LC resonance circuit.

FIG. 6 shows a second example of the liquid detection sensor 21 used in the present invention. The formation order of the liquid detection sensor 21 is the same as that shown in FIG. 4, but the example shown in FIG. 6 is a routing wiring for connecting the capacitor C1 and the coil L1, and is an outward wiring at the folded-back tip portion 30e. It is formed by substantially one conductor wiring forming 30c and the return wiring 30d. The outbound wiring 30c and the inbound wiring 30d are arranged in parallel and adjacent to each other on the 22nd surface of the base material.

When the outbound wiring 30c and the inbound wiring 30d are arranged in parallel with each other (close to each other) in this way, the detection ability can be further improved because the wiring can be broken at the same place by either of the two back and forth wires. By adopting such an arrangement form of the routing wiring, the detection ability on the reader 11 side can be maintained in a high state.
In the example shown in FIG. 6, the outbound wiring 30c and the inbound wiring 30d are formed in an L shape and are formed along the upper surface of the wiring breaking layer 26. However, such a shape may be designed to be placed in a part of the diaper that is easily wet due to incontinence.

Further, also in the example shown in FIG. 6, the length dimension of the routing wiring by the outward wiring 30c and the return wiring 30d is formed to be larger than the length dimension of the long side of the rectangular coil conductor 29. By increasing the length dimension of the routing wiring 30, the liquid detection area can be substantially expanded as in the example shown in FIG. 5, which can contribute to the improvement of reliability as a liquid detection sensor.
In the liquid detection sensors shown in FIGS. 5 and 6, although not shown in the figure, a wiring breakage layer 26 is also provided between the base material 22 and the spiral conductor 29 forming the coil L1. By forming the film, the liquid detection area can be expanded to the formation region of the coil L1.

FIG. 7 describes the detection function of the detection sensor obtained on the reader 11 side by using the detection sensor 21 shown in FIGS. 5 and 6 as a wireless tag.
As the LC resonance circuit formed in the detection sensor 21, for example, one having a resonance characteristic in the vicinity of 11 MHz is used. Then, the detection radio wave transmission device 13 of the reader 11 shown in FIG. 3 supplies the detection radio wave whose frequency sweeps in the range of ± several MHz around 13.56 MHz to the antenna 12.
Therefore, the detection sensor 21 attached to the diaper 3 of the care recipient 2 on the bed 1 receives an electromagnetic wave whose frequency is swept from the antenna 12 laid on the bed 1.

In the graph shown in FIG. 7, the relationship between the frequency fG of the alternating magnetic field due to the electromagnetic wave whose frequency sweeps and the supply current IG supplied from the detection radio wave transmitting device 13 to the antenna 12 at this time is shown. The horizontal axis in FIG. 7 indicates the time t.
When the frequency fG of the AC magnetic field sweeps and matches the resonance frequency fR1 of the LC resonance circuit of the detection sensor 21 (fG1 = fR1), the LC resonance circuit of the detection sensor 21 generates resonance vibration. As a result, the antenna 12 acts to supply the energy required for the magnetic field, and the supply current IG to the antenna 12 increases.
This state can be captured as a decrease in the voltage of the oscillating coil (dip) on the detection radio wave transmission device 13 side of the reader 11, and this dip can be detected by the discrimination device 14 shown in FIG.

Therefore, as shown in FIG. 7, when the dip is detected, it is confirmed that the LC resonance circuit of the detection sensor 21 is operating, which means that the diaper 3 of the care recipient 2 on the bed 1 is operating. It can be determined that the state is dry.
Further, when the diaper 3 of the care recipient 2 is wet, at least a part of the above-mentioned routing wiring is destroyed and the LC resonance circuit becomes inoperable, so that the dip is not detected, and thus the subject is covered. The caregiver 2 can be determined to be incontinent.
When the reader 11 does not detect the dip, the information is transmitted from the reader 11 to the host computer 5 of the nursing facility together with the address code of the bed, for example, by using a wireless LAN, as shown in FIG. ..

By the way, in the first embodiment described with reference to FIG. 7, the dip cannot be detected when the care recipient 2 is away from the bed 1, and therefore the diaper of the care recipient 2 It is not possible to determine whether the 3 is wet or the care recipient 2 is away from the bed 1.
Therefore, in the second embodiment, the above-mentioned detection sensor whose part is partially destroyed by moisture is used as the first detection sensor, and has a resonance frequency different from the resonance frequency of the first detection sensor, and is resonated by moisture. A liquid detection device including a second detection sensor that does not break the circuit is provided.

That is, the first detection sensor and the second detection sensor are both mounted on the diaper 3, and the reader 11 is configured to detect the presence or absence of the resonance frequency of each detection sensor.
In this case, the first detection sensor and the second detection sensor may be configured on one film base material 22, or two independently configured detection sensors are individually mounted on the diaper 3. You may.

Although the second detection sensor is not particularly shown, a configuration in which the wiring breakage layer 26 shown in FIG. 4B is not formed is adopted. In addition, the dielectric layer 25 is printed using a material having a weak hydrophilicity that does not swell with a liquid, for example, urethane resin.
Further, as the second detection sensor, a sensor having the same configuration as the first detection sensor and having a resin coating on the sensor to block the influence of moisture can also be used.

FIG. 8 shows the detection characteristics adopted in the second embodiment, and the vertical and horizontal axes of the graph shown in FIG. 8 are the same as the graph shown in FIG. 7 described above.
The graph shown in FIG. 8 is configured to detect dip (fG2 = fR2) by the second detection sensor in addition to the detection characteristics of the graph shown in FIG. 7.
In this case, the resonance frequency fR2 of the LC resonance circuit of the second detection sensor 21 is preferably set to 14 MHz.

FIG. 9 is a flowchart illustrating a detection operation mainly performed by the discriminating device 14 in the reader 11 shown in FIG. 3 in the second embodiment. Hereinafter, the detection operation in the second embodiment will be described with reference to FIG.

The reader 11 transmits the detection radio wave in step S1. As a result, as shown in FIG. 8, an alternating magnetic field swept by the frequency fG is formed around the antenna 12.
In step S2, the discriminating device 14 in the reader 11 detects the presence or absence of the dip by the first and second detection sensors in this state.

Subsequently, in step S3, it is verified whether or not the dip exists in the vicinity of fR2. If it is determined in step S3 that the dip does not exist in the vicinity of fR2 (No), it is determined that the care recipient 2 is absent from the bed 1 as shown in step S4. If it is determined in step S3 that the dip exists in the vicinity of fR2 (Yes), it is verified in step S5 whether or not the dip exists in the vicinity of fR1.

When it is determined in step S5 that the dip exists in the vicinity of fR1 (Yes), as shown in step S6, the care recipient 2 is present in the bed 1 and the diaper 3 is in a dry state. to decide.
Further, in step S5, when it is determined that the dip does not exist in the vicinity of fR1 (No), the care recipient 2 exists in the bed 1 and the diaper 3 is in a wet state as shown in step S7. Judge that.

As described above, the determination result of any of the steps S4, S6, and S7 is transmitted from the reader 11 to the host computer 5 of the nursing facility together with the address code of the bed 1 using, for example, a wireless LAN.
In the operation flow shown in FIG. 9, the operations of steps S1 to S8 described above are repeated to perform the detection operation in real time, and the final step of the cycle is the predetermined waiting time shown in step S9. The process is inserted and the timing of the process operation is adjusted.

In the second embodiment described above, the diaper 3 is worn by installing the reader 11 and the antenna 12 at the entrance and exit of the facility and monitoring the dip near fR2 described above. It is possible to detect the behavior of the caregiver 2 going out without permission.

According to the liquid detection sensor and the liquid detection device according to the present invention described above, an inexpensive liquid detection sensor can be provided, and the state of the diaper worn by the care recipient can be reliably detected. It is possible to obtain the action and effect as described in the column of the effect of the invention.

Since the liquid detection device according to the present invention can be basically configured by a combination of the detection sensor 21 and the reader 11, it can be used not only in the above-mentioned nursing care facility but also in home care. It can exert its function.
Further, the liquid detection device according to the present invention can also be used as a liquid detection device for detecting a state of water leakage, for example, in addition to nursing care by utilizing the above-mentioned functions.

1 Bed 2 Care recipient 3 Diaper 5 Host computer 6 Wireless LAN transmitter / receiver 7 Caregiver 8 Portable receiver 11 Reader 12 Antenna 13 Detection radio wave transmitter 14 Discrimination device 16 Liquid detection device (incontinence detection device)
21 Liquid detection sensor (incontinence detection sensor)
22 Film base material 23 First electrode (lower electrode)
24 Bypass wire 25 Dielectric layer 26 Wiring breakage layer 27 Insulation layer 28 Second electrode (upper electrode)
29 Coil conductor 30 Route wiring 30a Connection line 30b Connection line 30c Outward wiring 30d Inbound wiring 30e Folded tip C1 capacitor L1 coil

Claims (5)

As a flexible substrate a sheet film, two connecting both with the capacitor and the coil conductor on the substrate surface is formed, in between the adjacent arranged the condenser and the coil conductor wiring, together with the capacitor and the coil conductor on the substrate surface, the resonant circuit is formed by being applied by coating or printing using a conductive ink,
One of the two wirings is a routing wiring that connects the first electrode forming the capacitor and one end of the coil conductor formed in a spiral shape.
The other of the two wires is a bypass wire connecting the second electrode forming the capacitor and the other end of the coil conductor.
The length dimension of the routing wiring on the substrate surface is formed to be larger than the length dimension of the long side of the rectangular coil conductor or the diameter of the circular coil conductor.
And between said substrate and said lead-out lines, by expanding contain water, or to dissolve contain water, the arranged wiring failure layer for cutting the lead wires Rutotomoni, the lead The wiring is formed by a single conductor wiring connecting the outward wiring and the return wiring at the folded-back tip portion, and the outward wiring and the return wiring are arranged adjacent to each other on the base material surface. Liquid detection sensor. A claim characterized in that the wiring breaking layer that expands or dissolves containing water is arranged at a plurality of locations along the longitudinal direction of the routing wiring so as to intersect in the longitudinal direction of the routing wiring. Item 1. The liquid detection sensor according to item 1 . It is characterized in that sodium polyacrylate is used for the wiring breaking layer that expands with water, and polyacrylic acid or polyvinyl alcohol with a low degree of polymerization is used for the wiring breaking layer that dissolves with water. The liquid detection sensor according to claim 1 or 2 . A liquid detection device that detects the state of the liquid detection sensor in a non-contact manner with the liquid detection sensor according to any one of claims 1 to 3 attached to an inspection target.
The detection radio wave emitting means that sweeps and emits the frequency of the detected radio wave to the liquid detection sensor and the change in the transmitting side current in the detected radio wave emitting means when the resonance frequency of the liquid detection sensor is matched are detected. As a result, the liquid detection device is provided with a discriminating means for discriminating a wet or dry state due to the liquid in the inspection target. The liquid detection sensor according to any one of claims 1 to 3 is attached to an inspection target as a first liquid detection sensor, and a resonance circuit having a resonance frequency different from the resonance frequency of the first liquid detection sensor is provided. It is a liquid detection device that detects the states of the first liquid detection sensor and the second liquid detection sensor in a non-contact manner with a second liquid detection sensor that is not destroyed by moisture and the resonance circuit is further attached to the inspection target. hand,
The detection radio wave emitting means that sweeps and emits the frequency of the detection radio wave to the first liquid detection sensor and the second liquid detection sensor matches the resonance frequency of the first liquid detection sensor and the second liquid detection sensor. A liquid characterized in that it is provided with a discriminating means for discriminating the presence or absence of the inspection target and the wet or dry state due to the liquid of the inspection target by detecting each change in the transmitting side current in the detection radio wave emitting means at the time. Detection device.

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