JPH0621018Y2 - Sensor that can detect water content in diapers - Google Patents

Description

[Detailed Description of the Invention] Industrial Field of the Invention [0001] The present invention relates to a sensor capable of detecting the amount of water in a diaper, and in particular, it can be repeatedly used for ordinary cloth, paper or the like without adding a significant constitution to the diaper itself. Even in diapers or disposable diapers, by inserting the diaper at an appropriate place, when a bedridden elderly person, a sick person, etc. has a stool, a third party senses the water content and immediately replaces it as necessary. It relates to a sensor that can.

2. Description of the Related Art In recent years, with the progress of an aging society and the increase in longevity due to the progress of modern medicine, the so-called "sleeping old people" tend to increase. It is said that more than 30% of the elderly hospitals are occupied by the "sleeping old people".
In nursing these patients, the treatment of urine and feces is a major problem, and it is considered that if the urine and feces alone can be easily treated, the burden on the patient and the caregiver will be reduced.

Conventionally common urine treatment methods are roughly classified into treatment after natural urination using a diaper-based orthosis and continuous urination treatment by wearing an indwelling catheter such as a balloon catheter. Regarding the treatment with the above-mentioned brace, since it is unknown when the patient, the elderly or the infant performed the stool, it is common for the nurse to divide the time and change the diapers of many patients all at once. The current situation. Therefore, depending on the patient, the condition that they have been using the feces for a long time will continue, which causes discomfort and
This results in diaper rash, chills, bedsores, and other pain.

On the other hand, a good electric conductor such as an electric wire is installed in the diaper as a means for detecting feces by using the water contained in the excrement.
Attempts to issue a warning signal to the outside by detecting the change in the electric conductor (for example, Japanese Utility Model Publication No. 59-37555, Japanese Utility Model Publication No. 5).
9-37556). In the case of such a device, even if it is possible to determine the presence or absence of stool, it is not possible to detect the degree of wetness of the diaper. Therefore, the applicant of the present application has previously determined the moisture content shown in FIGS. 6 and 7. A diaper that can be sensed is invented and applied (Practical application Sho 59-7155)
No. 8 (see Jitsukai Sho 60-181311).

In the figure, 21 is a water-permeable top sheet, 22 is a water-absorbing layer, and 23 is a water-impermeable back sheet. One ends 23a and 23a of the back sheet 23 are bent so as to cover the water-absorbing layer 22. The metal layers 24, 24 are formed so as to be sandwiched from both sides thereof. Two
Reference numerals 5 and 25 are lead wires derived from the metal layers 24 and 24. According to such a configuration, the back sheet 23 sandwiching the water absorbing layer 22 and the metal layers 24, 24 form a capacitor, and the capacitance of the capacitor changes depending on the amount of water adsorbed by the water absorbing layer 22, so that the lead wire 25, If 25 is connected to a separately provided measuring device and the change in capacitance is measured, the amount of water adsorbed on the water absorption layer 22 can be quantitatively obtained.

Problems to be Solved by the Invention According to the conventional means as described above, when the former, i.e., when the orthoses are replaced all at once by dividing the time, depending on the patient, the state in which the stool is kept for a long time continues, This causes discomfort and causes discomfort such as diaper rash, coldness, and bedsores.

The latter, that is, the means utilizing the change in the capacitance of the capacitor, can determine the amount of water adsorbed to the water absorption layer 22, so that it is possible to replace only the diaper that needs to be replaced, and the patient is discomforted. Although there is an advantage that a usage state not given is obtained, the distance between the metal layers 24, 24 forming the electrodes of the capacitor may change depending on the usage state, and the measured capacitance may change. That is, the capacitance is proportional to the product of the areas of the metal layers 24 and 24 serving as the counter electrodes and the dielectric constant of the water absorbing layer 22, and is inversely proportional to the distance between the counter electrodes 24 and 24, and thus the above-described measurement result is obtained. It will be.

Further, since the above-mentioned means has a structure in which a metal layer or the like for forming an electric wire or a capacitor is adhered and formed in the diaper as a structure of the diaper itself, each diaper is manufactured by a dedicated diaper. The purpose cannot be achieved without it. Therefore, a processing step of attaching the above-mentioned electric wire or metal layer to the inside of a large number of mainly disposable diapers is required. In addition, the prevalence of disposable diapers for adults such as bedridden elderly people is still low, and reusable diapers such as cloth are often used.

Therefore, the present invention has been made in view of the above,
Even if you use not only a dedicated diaper for sensing the amount of water but also a normal cloth repeatable diaper or disposable paper diaper, a sensor separate from the diaper body is inserted in the diaper. It is intended to provide a means by which the degree of stool can be sensed by inserting.

Means for Solving the Problems In order to achieve the above-mentioned object, the present invention is a sensor for detecting the amount of water in a diaper that can be repeatedly used or a disposable diaper. A back sheet, two rows of metal layers formed in parallel with each other while maintaining a constant distance along the longitudinal direction of the back sheet, and an electric insulating layer coated on the surface of one metal layer, A moisture-permeable topsheet that covers the tops of both metal layers,
It is composed of a lead wire derived from the end portions of both metal layers, and by applying an AC voltage between the both metal layers,
It is intended to provide a sensor for detecting a change in capacitance of a capacitor formed by both metal layers, an electric insulating layer and a surface sheet, and confirming a degree of water adsorption state of a diaper.

Action By inserting the above sensor into a diaper that can be repeatedly used or a disposable diaper, a capacitor is formed by the electric insulation layer and the surface sheet that cover the surfaces of the two rows of metal layers and the metal layer on one side. To be done. Therefore, when the moisture is adsorbed on the moisture-permeable surface sheet of the sensor by the stool, the area of the metal layer that does not cover the electric insulation tank as an electrode is expanded by the moisture, and both the metal layer and the electric insulation layer. And the electrostatic capacitance of the capacitor formed by the surface sheet changes.

Therefore, by measuring this capacitance, the amount of water, that is, the degree of water adsorption state of the diaper can be confirmed. Moreover, since the metal layer is adhered and formed in parallel along the longitudinal direction of the water-impermeable backsheet at a constant interval, the distance of the metal layer does not change depending on the use condition and is stable. Can measure.

Since the sensor is separate from the body of the diaper, any diaper such as a cloth diaper that can be used repeatedly and a simple disposable diaper can be used by simply inserting it.

Embodiment Hereinafter, a detailed description of the present invention will be given with reference to the drawings.

FIG. 1 is a plan view showing an embodiment of a sensor capable of detecting the amount of water according to the present invention, and FIG. 2 is a sectional view taken along line II-II of FIG. In the figure, 1 is a water-impermeable backsheet, 2 and 3 are metal layers deposited in parallel on the backsheet 1, 4 is an electrical insulating layer covering the top of the metal layer 2, and 5 is a water-permeable It is a surface sheet. The back sheet 1 is a plastic film made of polypropylene, polyethylene, polyester, vinyl chloride or the like having a substantially rectangular shape with a thickness of 3 to 30 μm. The metal layers 2 and 3 are made of a material such as aluminum, zinc, copper or tin, and are formed by lamination or vapor deposition in parallel along the longitudinal direction of the backsheet 1 with a constant space.

The width of the metal layers 2 and 3 is 5 to 20 mm and the thickness is 15 μm.
It is preferable that the thickness is less than or equal to m and the distance between the two metal layers 2 and 3 is about 2 to 20 mm.

The electric insulating layer 4 is formed of silicon resin, acrylic resin, polyamide resin, polyimide resin, nitrile rubber, wax, sodium silicate, polyvinyl alcohol, vinyl acetate or the like into a thin film having a thickness of 20 μm or less. Or thickness 2
Lamination may be performed using a plastic film of 20 μm polypropylene, polyethylene, polyester, polyamide or the like.

The topsheet 5 is a paper having a thickness of 15 to 150 μm or a non-woven fabric such as rayon, polypropylene or polyester fiber having a basis weight of 120 g / m ² or less, and the backsheet 1 including the metal layers 2 and 3 and the electrical insulation layer 4. Is formed by covering the entire upper surface of the. The topsheet 5 has a structure capable of absorbing water to form a continuous phase of water. Then, the lead wires 6 and 7 are led out from the end portions of the metal layers 2 and 3.

The sensor 8 configured as described above preferably has a width of about 100 mm and a length of 600 mm or less from the viewpoint of use.

FIG. 3 shows a state in which the sensor 8 according to the present invention is inserted into an ordinary cloth diaper 9. By connecting the lead wires 6 and 7 to a measuring circuit (not shown), the change in capacitance is read, the water content is sensed, and the alarm device is activated.

In the sensor 8 according to the present invention, a capacitor is formed by the two rows of metal layers 2 and 3, the electric insulating layer 4 covering the surface of the metal layer 2 on one side, and the moisture permeable surface sheet 5, and thus, according to convenience. When moisture is adsorbed by the moisture-permeable surface sheet 5 of the sensor 8 inserted in the diaper 9, the area of the metal layer 3 not covering the electrical insulating layer 4 as an electrode is expanded by the moisture, Metal layers 2 and 3 and electrical insulation layer 4
The capacitance of the capacitor formed by and changes. Then, the capacitance of the capacitor, which changes according to the state of water adsorption from the diaper 9 to the sensor 8, is measured, so that the sensing of the amount of water, that is, the degree of the state of water adsorption of the diaper can be confirmed.

There are various means for measuring the electrostatic capacitance, but as a main method, the AC bridge method defined in JIS-C-5102 (Testing method for fixed capacitors for electronic devices),
A parallel resonance method and a series resonance method are used. FIG. 4 illustrates a measurement circuit based on the series resonance method. In the figure, 11 is a capacitor formed in the diaper based on the above configuration, 12 is a tuning variable capacitor, 13 is an electronic voltmeter,
14 is a coil of constant inductance, 15 is a coupling resistance,
Reference numeral 16 is a high frequency ammeter, and 17 is an AC power supply. The capacitance Qx of the capacitor 11 is measured as follows. First, the coil 14 having an inductance corresponding to the frequency of the AC power supply 17 is selected and adjusted so that the frequency of the AC power supply 17 becomes a specific value, and then the tuning variable capacitor 12 is adjusted so that the electronic voltmeter 13 operates. The maximum point Q1 is obtained, and the electrostatic capacitance C1 of the variable capacitor 12 at that time is read.
Next, after connecting the capacitor 11 and the variable capacitor 12 in parallel, a point Q2 at which the electronic voltmeter 13 becomes maximum is obtained in the same manner as above, and the electrostatic capacitance C2 of the variable capacitor 12 at that time is read. As a result, the capacitance Q of the capacitor 11
x is calculated | required by Qx = C1-C2 ... (1).

The value of the capacitance Qx measured as described above varies depending on the amount of water adsorbed on the sensor 8. That is, the capacitance is proportional to the product of the area of the metal layers 2 and 3 to be the counter electrodes and the dielectric constant of the surface sheet 5, and is inversely proportional to the distance of the counter electrodes. When water is adsorbed on the water-permeable topsheet 5 of No. 8, the area of the metal layer 3 not covering the electric insulating layer 4 as an electrode is expanded by the water, and the electric insulation between both metal layers 2 and 3 is achieved. The capacitance of the capacitor formed by the layer 4 and the topsheet 5 changes. Therefore, as shown in Fig. 5, the water content (8%)
The correlation graph between Qx and Qx is obtained, and the value of the capacitance Qx differs depending on the wetness of the sensor 8.

Effect of the Invention The above has described in detail the sensor capable of sensing the water content in the diaper according to the present invention. However, the use of the present invention can bring about the following operational effects. That is, the capacitor is formed by the electric insulating layer and the surface sheet that cover the surfaces of the two rows of metal layers of the sensor that are configured separately from the diaper and the metal layer on one side, and the surface sheet is a part of the capacitor. Therefore, by measuring the capacitance of the capacitor, which changes according to the state of water adsorption to the sensor inserted in the diaper by the stool, the amount of water, that is, the state of water absorption of the diaper. The degree of can be detected.

Moreover, since the metal layer is adhered and formed in parallel on the same plane of the water-impermeable back sheet facing the water-permeable top sheet, the distance between the metal layers forming the electrodes of the capacitor changes depending on the use condition. Since it does not occur, the measured capacitance does not fluctuate, and accurate measurement results can always be obtained.

Since the present invention is a sensor separate from the diaper main body, any diaper such as a cloth diaper that can be repeatedly used or a simple disposable diaper can be used by simply inserting it. Further, since the two rows of metal layers are strongly adhered and formed by laminating or vapor deposition, wire breakage does not occur due to bending during movement or movement of the human body. Therefore, when the disposable diaper according to the present invention is used in a hospital or the like in which a large number of patients, elderly people, infants, etc. are accommodated, a convenience is provided by using a meter and an alarm device that can sense the water content for each individual. There is an advantage that it is possible to immediately determine whether or not the patient name and the amount of stool are enough to replace the diaper. Therefore, since the diaper only for the patient concerned can be replaced, the patient does not feel uncomfortable, a favorable usage condition is obtained from the viewpoint of hygiene, and unnecessary diaper operation is unnecessary, and the diaper itself. Since it may be a normal one, it is economically advantageous.

After use, only the sensor can be incinerated. If the diaper is made of normal cloth, only the used sensor can be discarded, the diaper can be washed and reused, and if the diaper is disposable such as paper, it can be incinerated as it is. Therefore, if the sensor according to the present invention is used,
It can be used regardless of whether it is a disposable diaper or a reusable diaper, and it is extremely effective when used in hospitals, clinics and the like. Moreover, since the sensor according to the present invention is manufactured separately from the diaper, the sensor is easier to manufacture than a conventional diaper in which a metal layer or the like for forming a capacitor is attached. It can be provided at low cost.

[Brief description of drawings]

FIG. 1 is a plan view showing a sensor capable of detecting the amount of water according to the present invention, FIG. 2 is a sectional view taken along line II-II of FIG. 1, and FIG. 3 is a perspective view showing a use state of the present invention. FIG. 4 is a circuit diagram for measuring capacitance, FIG. 5 is a characteristic graph showing the correlation between water content and capacitance, and FIG. 6 is a plan view showing a conventional disposable diaper capable of sensing water content. The drawing is a sectional view taken along the line II-II in FIG. 1 ... Back sheet, 2, 3 ... Metal layer 4 ... Electrical insulating layer, 5 ... Front sheet 6, 7 ... Lead wire, 8 ... Sensor

Claims (1)

[Scope of utility model registration request] 1. A sensor for detecting the water content of a diaper which is repeatedly inserted into a diaper or a disposable diaper, wherein the sensor is a substantially rectangular water-impermeable back sheet, and the back sheet. The two rows of metal layers that are formed in parallel along the lengthwise direction of the metal layer are formed in parallel with each other, the electrically insulating layer that is coated on the surface of the metal layer on one side, and the moisture that covers the upper surfaces of both metal layers. It is composed of a transparent surface sheet and lead wires led out from the end portions of both metal layers, and is formed by both metal layers, an electric insulating layer and a surface sheet by applying an AC voltage between the both metal layers. A sensor capable of detecting the amount of water in a diaper, which detects the change in the capacitance of a capacitor and confirms the degree of water absorption of the diaper.