WO2019035552A1

WO2019035552A1 - Excreta detection device for diaper and excreta detection reader

Info

Publication number: WO2019035552A1
Application number: PCT/KR2018/007317
Authority: WO
Inventors: 곽병재
Original assignee: 주식회사 큐유아이
Priority date: 2017-08-14
Filing date: 2018-06-28
Publication date: 2019-02-21

Abstract

Provided are an excreta detection device that is for a diaper and capable of detecting excreta present in the diaper, and an excreta detection reader for transmitting and receiving signals to and from the excreta detection device for the diaper and notifying a user about whether excreta is present. Since the large scale of a resonant frequency is determined on the basis of a capacitor which is isolated from the excreta and not affected by the excreta and the small scale of the resonant frequency that changes due to the excreta may be determined on the basis of a capacitor having a permittivity that changes due to the excreta, the excreta may be detected even when a relatively narrow frequency band is swept. In addition, since excreta sensing is not performed at only a specific resonant frequency but is also performed by comparing resonant frequencies before and after defecation, the excreta sensing can be performed regardless of the state of the excreta.

Description

Disposer Detector for Diapers and Manure Detector

The present invention relates to a manure detection apparatus and a manure detection reader for a diaper, and more particularly, to a manure detection apparatus for detecting a target substance (for example, manure or the like) present in a diaper, and a manure detection reader for informing a user of manure information to be.

Infants, the elderly, and patients with uncomfortable mobility who can not handle the toilet themselves usually wear diapers to solve the defecation problem. Most of the users wearing diapers are not able to wear new diapers themselves because their cognitive ability, communication ability or body ability is poor, and it is often difficult to notify their caregivers about the status of bowel movements. If new diapers are not worn, manure remaining in the diaper causes diseases such as erythema and erythema. To prevent this, the guardians often observe the outside of the diaper through tactile, visual, or olfactory You should check yourself. However, it is difficult for the caregivers to check the condition of the diaper from time to time, and it takes a lot of time for one person's guardian to confirm the defecation status of a large number of users. Furthermore, in recent years, as the tightness of the diaper increases, it becomes more difficult to confirm whether the diaper is defecated without detaching the diaper. In order to solve this problem, a device based on a semiconductor device in which the resonance frequency of the resonance circuit varies as the permittivity is changed by the manure and the manure is determined to exist if a certain frequency is included in the changing resonance frequency range, There is a problem that a manufacturing cost is high and power must be supplied for driving. A device for measuring the change in resonance frequency based on a change in capacitance through a switching method that is switched on and off by the manure can also be used for manure detection but a switch that is turned on and off to change the capacitance depending on the presence of manure The structure is complicated and the manufacturing cost is also high. Although a device for detecting a change in resonance frequency based on a continuous change in the permittivity of a capacitor due to manure can also be used for detecting manure, the permittivity difference of the capacitor is extremely large depending on whether the compartment is defecated. It is necessary to sweep the frequency of < / RTI >

It is possible to provide a manure detection device having a small size and a low manufacturing cost because it is supplied with wireless power without having to provide its own power source.

The change in resonance frequency before and after defecation is determined based on the change in capacitance of the capacitor caused by the manure in the diaper, so that it is possible to provide a manure detection apparatus of a relatively simple structure without a switch structure.

It is possible to provide a manure detection device having a structure capable of narrowing the sweep frequency range for measuring the resonance frequency and a manure detection reader that can be used with the same.

A manure detection apparatus according to an embodiment of the present invention includes at least one inductance element; At least one fixed capacitance element configured so that capacitance does not change even if manure is present in the diaper; And at least one variable capacitance element electrically connected to the at least one fixed capacitance element and arranged such that capacitance changes when manure is present in the diaper, wherein the at least one inductance element, the at least one fixed capacitance element And at least one first resonant frequency may be determined based on the at least one variable capacitance element.

Wherein the at least one variable capacitance element changes its dielectric constant when it absorbs manure to change the capacitance of the at least one variable capacitance element; And spaced conductors sandwiching the absorber.

Furthermore, the at least one variable capacitance element may further include at least one insulating layer between the absorber and the conductors to prevent direct exposure of the conductors to the manure absorbed by the absorber. At this time, the insulating layer may exist irrespective of whether the absorber is present or irrespective of the arrangement of the absorber.

The capacitance of said at least one variable capacitance element changes when manure is present in the diaper, and at least one of said at least one inductance element, said at least one fixed capacitance element and said capacitance is changed at least based on said at least one variable capacitance element One second resonant frequency is determined, and the at least one first resonant frequency and the at least one second resonant frequency may be different from each other.

The manure detection reader according to an embodiment of the present invention includes a power source unit for generating a first alternating magnetic field whose frequency changes in order to induce an electromotive force in the manure detection apparatus; A sensor unit for sensing a parameter related to a second alternating magnetic field generated by inducing the electromotive force by the manure detection device; A controller for determining whether or not manure is present based on parameters related to a second alternating magnetic field sensed by the sensor; And an output unit for informing the user whether or not the manure is present.

The power supply unit may generate a first alternating magnetic field whose frequency varies within a frequency band including the at least one first resonance frequency and the at least one second resonance frequency.

The parameter may be an amplitude or an impedance of an induction current or induction voltage for each frequency.

The controller may determine a resonance frequency based on the parameter value, and compare the resonance frequency with at least one first resonance frequency or at least one second resonance frequency to determine whether or not manure is present.

The control unit may determine the resonance frequency before the presence of manure and the resonance frequency after the presence of manure based on the parameter values and compare the resonance frequency before the presence of the manure and the resonance frequency after the presence of the manure to determine whether or not the manure exists .

An apparatus for detecting the presence of a target material includes at least one fixed capacitance element configured to prevent a change in capacitance even in the presence of a target material; And at least one variable capacitance element electrically connected to the at least one fixed capacitance element and arranged such that a capacitance changes when manure is present in the diaper; Wherein at least one first resonant frequency can be determined based on the at least one fixed capacitance element and the at least one variable capacitance element.

The manure detection device according to the present invention is small in size and low in manufacturing cost because it is supplied with a wireless power source without having to have its own power source.

The manure detection device according to the present invention is a relatively simple structure without a switch structure because it judges a change in resonance frequency before and after defecation based on a change in capacitance of a capacitor (in particular, a variable capacitor) caused by manure in a diaper.

The manure detection apparatus according to the present invention and the manure detection reader that can be used therewith have a structure capable of narrowing the sweep frequency range for measuring the resonance frequency.

1 is a view for explaining a manure detection apparatus and a manure detection reader according to an embodiment.

2 is an example of a graph showing parameter values sensed by the sensor unit of the manure detection reader.

3 is a view for explaining a conventional manure detection device.

4 is an example for explaining a manure detection apparatus according to the embodiment.

5 is another example for explaining a manure detection apparatus according to the embodiment.

6 is another example for explaining a manure detection device according to the embodiment.

Figs. 7 to 13 are views for explaining the structure of a capacitor element.

Fig. 14 shows an embodiment in which the interdigital capacitor shown in Fig. 13 is used as a variable capacitance element.

Fig. 15 shows an equivalent circuit for the embodiment shown in Fig.

16 shows an embodiment in which the parasitic capacitance of the inductor is used as a variable capacitance element.

17 shows an equivalent circuit for the embodiment shown in Fig.

Hereinafter, specific embodiments among various embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, this specific embodiment does not limit or limit the invention. The same reference numerals denote the same elements regardless of the reference numerals in the drawings, and a duplicate description will be omitted.

Embodiments of the present invention can be applied to a technique for detecting manure present in a diaper, but the present invention is not necessarily limited to such techniques. That is, those skilled in the art can easily derive a technique for detecting various substances from the technical idea of the present invention. For example, the embodiments of the present invention can be applied to detecting the presence or absence of any substance having various forms such as liquid, gas and solid. Hereinafter, the present invention will be exemplified on the assumption that the subject substance is manure present in the diaper.

1, the manure detection apparatus 100 may include a resonant circuit 110 and the resonant circuit 110 includes an inductance element 131, a fixed capacitance element 132, and a variable capacitance element 133 .

The variable capacitance element 133 varies in capacitance when manure is present in the diaper, and an absorber (not shown) for absorbing the manure may be present between the two conductors for this purpose. The presence of an absorber between two conductors means that the absorber is located where it can affect the capacitance formed by the two conductors. That is, not only when the absorber exists in the space between the conductors but also when the absorber is present around each conductor and can affect the capacitance.

When the inductance element 131 is practically implemented, a capacitance component (for example, a parasitic capacitance component) exists in the inductance element 131. Since the permeability, which affects the inductance of the inductance element, is a relatively less affected by the manure, the inductance changes relatively less even if the manure is located near the inductance element, but the capacitance of the capacitance element is close to It changes to such a degree that it can not be ignored as the permittivity changes. Rather than designing / arranging the variable capacitance element 133 as a separate element from the inductance element 131, it is possible to use a capacitance element (for example, a parasitic capacitance element) generated when the actual inductance element 131 is implemented To serve as a variable capacitance element.

In this case, the embodiment of the present invention can allow the element to have a desired capacitance and inductance in the process of designing a specific element. For example, by intentionally structuring the conductors included in a particular device, it is possible to make the device have the desired capacitance and inductance in a desired process.

In this specification, the variable capacitance element 133 is defined as a term including such a design parasitic capacitance component.

Even if the fixed capacitance element is disposed at a position that is hardly influenced by the manure or is designed to have a structure that minimizes the effect of manure or waterproofed so as to be hardly influenced, The capacitance of the fixed capacitance element can be changed finely. In the present specification, for the sake of convenience of explanation, it is described that the change of the minute capacitance is excluded, and the capacitance of the fixed capacitance element does not change by the manure.

The number of inductance elements and capacitance elements may be different from those shown in Fig. The combination of the inductance element and the capacitance element for obtaining a desired resonance frequency may be various, so that the number of the inductance element and the capacitance element may vary depending on the design.

The manure detection reader 140 may include a power source unit 150, a sensor unit 160, a control unit 170, and an output unit 180. 1 is described as including a power source unit 150, a sensor unit 160, a control unit 170 and an output unit 180. The power source unit 150, the sensor unit 160 At least one of the control unit 170 and the output unit 180 may be separated into separate modules. For example, the power supply unit 150 may be a module separated from the sensor unit 160, the control unit 170, and the output unit 180.

The power supply unit 150 can generate a first alternating magnetic field 191 having a specific frequency band by passing a current through the coil. The frequency band may be set to a band including the resonance frequency of the resonance circuit 110. [ An alternating magnetic field is a magnetic field generated by a coil through which an alternating current flows, which changes in magnitude and direction with time. An alternating magnetic field can be generated by causing a sinusoidal alternating current to flow through the coil.

The number of magnetic fluxes connected to the inductance element 131 of the resonance circuit 110 changes under the influence of the first alternating magnetic field 191 and an induced current flows in the resonance circuit 110. [ The inductance element 131 can generate the second alternating magnetic field 192 different from the first alternating magnetic field 191 when the induction current flows in the resonant circuit 110.

Since the impedance of the resonance circuit 110 varies depending on the frequency even if the amplitude of the first alternating magnetic field 191 is constant in all the frequency bands, the amplitude of the current also varies with frequency and ultimately the amplitude of the second alternating magnetic field 192 It will not be constant. Further, the resonance circuit 110 has the largest induced current at the resonance frequency, and the amplitude of the second alternating magnetic field generated by the induced current is the largest. That is, when the amplitude of the first alternating magnetic field 191 is constant in all the frequency bands, if the frequency band of the first alternating magnetic field 191 is swept and the second alternating magnetic field 192 is sensed, The amplitude of the magnetic field 192 is the largest.

At this time, the amplitude of the first alternating magnetic field 191, which is the input, can be made constant to measure the amplitude change of the second alternating magnetic field 192 and grasp the resonant frequency. Further, by increasing the selectivity (Quality Factor, Q) of the resonance circuit 110, it is possible to reliably confirm the characteristics of the amplitude at the vicinity of the resonance frequency.

The coil of the sensor unit 160 senses the second alternating magnetic field 192 and a current is induced in the sensor unit 160 by the second alternating magnetic field 192. When the amplitude of the first alternating magnetic field 191 is constant, the resonance frequency can be found using the amplitude of the second alternating magnetic field 192. Therefore, if the current induced by the second alternating magnetic field 192 is analyzed, It is possible to grasp which resonant frequency the antenna 110 has. A detailed embodiment is illustrated in Fig. The parameters for determining the resonant frequency can be voltage, impedance, etc., as well as the current.

For convenience of explanation, the coils of the power unit 150 and the sensor unit 160 are expressed differently, but the power unit 150 and the sensor unit 160 may have the same coil.

As used herein, the term " first resonance frequency " is a reference frequency indicating that no manure is present, and there may be one or more. The first resonant frequency may be a theoretical or experimentally determined resonant frequency value based on the element values of the inductance element, the variable capacitance element, and the fixed capacitance element in the absence of manure. In one example, the first resonant frequency may be determined based on the element value by the producer of the manure detection device or reader. In another example, the user may determine the first resonant frequency by determining the first resonant frequency by directly inputting the frequency value, or by measuring the resonant frequency after depressing the 'no manure present' button of the manure detection reader.

The 'second resonant frequency' may be one or more. The second resonant frequency is a reference frequency indicating the presence of manure. The resonance frequency value determined theoretically or experimentally based on the element values of the inductance element, the variable capacitance element and the fixed capacitance element in the presence of manure.

In one embodiment, when the resonance circuit in which the capacitance of the variable capacitance element 133 is not changed due to absence of manure in the diaper is referred to as a first resonance circuit, the first resonance frequency of the first resonance circuit is equal to the resonance frequency of the inductance element 131 ), The fixed capacitance element 132 and the variable capacitance element 133. In this case, when the power source unit 150 generates the first alternating magnetic field 191, the resonant circuit 110 generates the second alternating magnetic field 192 in response thereto, and the sensor unit 160 generates the second alternating magnetic field 192, Lt; / RTI > The controller 170 may measure the resonance frequency at that time and determine that the first resonance frequency and the first resonance frequency are the same within the error range to determine that no manure is present in the diaper.

Assuming that the resonance circuit in which the capacitance of the variable capacitance element 133 is changed in the manure present in the diaper is the second resonance circuit, the second resonance frequency of the second resonance circuit is the inductance element 131, the fixed capacitance element 132 And the variable capacitance element 133 whose capacitance has been changed, as compared with the first resonance frequency.

The control unit 170 measures the changed resonance frequency through the information received from the sensor unit 160 and determines that the second resonance frequency and the second resonance frequency are the same within the error range to determine that the manure exists in the diaper. The control unit 170 may cause the output unit 180 to provide a manure detection alarm to the user.

The first resonance frequency and the second resonance frequency may be included in the frequency band of the first alternating magnetic field 191 to measure the same first resonance frequency and the second resonance frequency within the error range.

The variable capacitance element 133 can be located close to the manure discharge position since the capacitance must be changed by the manure. In the case where the portion of the variable capacitance element excluding the absorber and the portion of the resonance circuit other than the absorber directly come into contact with the manure, the unexpected capacitance or change of the inductance or the parasitic resistance component may occur, , And further, the resonance circuit portion excluding the absorber can be insulated or waterproofed.

Although the spaced conductors (metal plates) in FIG. 1 are shown as substantially parallel flat plates, one embodiment of the present invention may include spaced apart metal plates of any structure that may have a capacitance. For convenience of explanation, the present invention will be described using parallel flat plates. Here, " conductor " or " metal plate " is not necessarily limited to a plane, but means an object or circuit made of a conductive material having any structure. For example, a circuit made of conductive ink or a circuit formed of a conductive material through etching should also be understood to be included in the category of a 'conductor' or a 'metal plate' as used herein.

Specifically, a graph 210 of the parameter value sensed by the sensor unit 160 through the first resonant circuit and a graph 220 of the parameter value sensed by the second resonant circuit are shown.

The graph 210 of the parameter value sensed by the sensor unit 160 through the first resonance circuit can confirm that the rate of change of the parameter value at f ₁ in the specific frequency band B is closest to zero. The control unit 170 can obtain the frequency at which the rate of change of the parameter value is closest to zero. The point at which the rate of change of the parameter value is closest to zero means a peak value in the graph shown in FIG. 2, so that the frequency at this point can be determined to obtain the resonance frequency. As shown in FIG. 2, f ₁ is obtained when no manure is present, and f ₂ when manure is present.

In one example, the controller 170 may determine that manure exists if the measured resonance frequency f ₁ and the measured resonance frequency f ₂ differ by more than a threshold value. For example, when the user obtains 1 MHz by measuring the resonance frequency of the manure detection device through the manure detection reader and then obtains 2 MHz by measuring the resonance frequency of the manure detection device again, It can be judged that manure exists.

The user can make sure that the control unit obtains f ₁ by measuring the resonance frequency after confirming that the manure is not reliably present in the diaper. For example, the user can input the 'no manure' input through an input unit (not shown) of the reader and then measure the resonance frequency so that f ₁ becomes the resonance frequency when there is no manure. Then, when the user measures the resonance frequency when manure is present in the diaper through the manure detection reader, the controller 170 can determine whether manure exists in comparison with f ₁ after obtaining f ₂ .

In one example, the controller 170 may determine that no manure is present in the diaper by determining that the measured resonance frequency, f _1, is equal to a first resonance frequency of the designed resonance circuit within a predetermined error range . For example, if the first resonance frequency is 1 MHz and f ₁ measured by the manure detection reader is 1.02 MHz, the controller 170 determines that the first resonance frequency and f ₁ are equal within a preset error range of 2% Lt; RTI ID = 0.0 > absence of manure. &Lt; / RTI > Likewise, the controller 170 determines that manure is present in the diaper by determining that the measured resonance frequency f ₂ is the same within a preset error range from the expected second resonance frequency when the variable capacitance is changed by the manure . For example, if the expected second resonance frequency is 3 MHz and f ₂ measured by the manure detection reader is 3.03 MHz, the controller 170 determines that the second resonance frequency and f ₂ are equal within a preset error range of 1% Thereby making it possible to determine that manure is present in the diaper.

In one example, the controller 170 judges the resonance frequency calculated theoretically based on the theoretical element value of the variable capacitance element, the fixed capacitance element, and the inductance element or the actual element value as the first resonance frequency or the second resonance frequency In addition to this, when the user desires, for example, the 'resonance frequency measured after depressing the' no manure 'button may be determined as the first resonance frequency.

In one example, the controller 170 may determine a frequency at which the rate of change of the parameter value is closest to zero, and then compare the frequency with a preset frequency threshold value to determine whether manure is present. For example, it can be determined that f ₁ , measured at ₁ MHz, is greater than a preset threshold of 0.9 MHz to determine that manure is absent.

In one example, the controller 170 may determine whether f ₁ is between a predetermined frequency threshold range and determine that no manure exists. For example, it can be determined that f ₁ , measured at ₁ MHz, is less than 0.9 MHz and less than 1.2 MHz, which is a predetermined frequency range, to determine that no manure exists.

The output unit 180 may provide information to the user that manure is not present through a display, sound, or the like.

Figure 2, f _1> f _2, but as shown, in accordance with the design of the resonance circuit may be a f ₁ <f _2. In addition to the method of determining the frequency at which the rate of change of the parameter value is the closest to zero in the method of finding the resonance frequency, a method of judging the frequency at which the rate of change of the parameter value is largest as the resonance frequency, The resonance frequency is measured using a parameter value such as a method of determining the frequency at which the parameter value is maximized and a method of determining the frequency at which the parameter value is maximized as the resonance frequency, and the presence or absence of the manure is judged according to an embodiment of the present invention.

In one embodiment, the manure detection reader can measure multiple resonance frequencies in each of the states before and after defecation, using multiple resonance frequencies, even with one circuit, depending on the structure of the resonant circuit, By comparing the difference with a predetermined threshold value, it is possible to judge each state before and after defecation.

For example, if the first resonant circuit generates two resonant frequencies, the manure detection reader measures the two resonant frequencies of the first resonant circuit and compares the difference between the two resonant frequencies with a predetermined threshold to determine that manure is absent . In the same way, the manure detection reader can determine that manure is present in the diaper by comparing the difference between at least two resonance frequencies of the second resonant circuit to a predetermined threshold.

If a physical external force is applied to the resonance circuit, physical deformation may occur in the inductance element or the capacitance element, which jointly affect each of the two resonance frequencies. At this time, in each of the resonance frequencies of the first resonance circuit or the second resonance circuit, each of the resonance frequencies largely changes in value due to deformation of the inductance element, the capacitance element, and the like, More stable manure detection is possible.

In addition, embodiments of the present invention may be modified in various ways. For example, there may be two resonant frequencies before the presence of manure, but the number of resonant frequencies may vary, such as when there is one resonant frequency in the presence of manure, It is possible to detect a change in the number of frequencies. On the contrary, the embodiment of the present invention is also applicable to the case where there exists one resonance frequency before the presence of manure but there are two resonance frequencies in the presence of manure.

Furthermore, not only the change in the number of resonant frequencies, but also the frequency shift of the resonant frequency can be detected. For example, two resonant frequencies for manure prior to the presence of manure can be reduced or increased while maintaining the spacing between manure and manure, and embodiments of the present invention can be applied to such cases.

3 is a view for explaining a conventional manure detection system.

Referring to FIG. 3, the conventional manure detection apparatus 310 includes a resonant circuit 320, and the resonant circuit 320 includes an inductor 330 and a variable capacitor 340. The variable capacitor 340 includes an absorber whose permittivity changes when exposed to manure, and the variable capacitance varies in accordance with the change of the permittivity. When the capacitance of the variable capacitor 340 changes, the resonance frequency determined by the inductor 330 and the variable capacitor 340 changes. The manure detection reader 350 measures the changed resonance frequency of the resonance circuit 320 to determine the presence or absence of manure in the diaper. For example, if the permittivity of the variable capacitor 340 is increased by 100 times by manure, the capacitance of the variable capacitor 340 is increased by 100 times according to the following equation (1).

[Relational expression 1] C _v =? S / d

ε is the permittivity of the material between the metal plates, d is the distance between the parallel metal plates, and S is the width of the metal plate. At this time, since the resonance frequency can be expressed by the following relational expression 2, if the capacitance is increased by 100 times, the resonance frequency is reduced to 1/10 by the manure.

[Expression _{2] f r = 1 / {} 2π (LC v 1/2}

For example, when the inductance of the inductor 330 is 1 (mH) and the capacitance of the variable capacitor 340 before the presence of manure is 1 (μF), the resonant frequency is 5033 Hz according to the relationship (2). If manure is present in the diaper and the capacitance of the variable capacitor 340 increases by 100 times, the resonance frequency becomes 503.3 Hz according to the relationship (2).

In general, when the dielectric that affects the capacitance is affected by the manure and the dielectric constant changes, the resonance frequency is greatly reduced because the dielectric constant may increase by several tens of times. The manure detection reader 350 measures both the first resonant frequency in the absence of manure in the diaper and the second resonant frequency in the presence of manure in the diaper. Thus, the manure detection reader 350 must sweep in a frequency range that includes the first resonant frequency and the second resonant frequency. In this case, if the dielectric constant is increased by several tens of times and the resonance frequency is greatly reduced, the frequency range to be swept is widened, so that the manure detection reader implementation becomes complicated and the manure detection speed may be slowed down.

4 is an example for explaining a manure detection system according to an embodiment.

4, a manure detection apparatus 410 according to an embodiment of the present invention includes a resonance circuit 420. The resonance circuit 420 includes an inductance element 430, a fixed capacitance element 440, And may include a capacitance element 450. The inductance element 430, the fixed capacitance element 440 and the variable capacitance element 450 are shown one by one for convenience of explanation, and the resonance circuit 420 may include one or more respective elements. A resonant circuit may be designed by a parallel connection, a series connection, or a combination thereof using one or more respective elements, but for convenience of explanation, one embodiment of the present invention will be described through a parallel resonant circuit.

The resonance frequency of the resonance circuit 420 is determined by the inductance element 430, the fixed capacitance element 440, and the variable capacitance element 450 according to the following relational expression (3).

[Expression _{3] f r = 1 / {} 2π (LC f + C v) 1/2}

When the capacitance of the variable capacitance element 450 is much smaller than the capacitance of the fixed capacitance element 440, the first resonance frequency can be expressed by the following relational expression (4).

(Relational expression 4) f _r _? 1 / {2? (LC _f ) ^1/2 } (C _f ? C _v )

For example, if the inductance is 1 (mH), the capacitance of the fixed capacitance element 440 is 1 (μF), and the capacitance of the variable capacitance element 450 is 1 (nF), the first resonance frequency Is about 5030 Hz. That is, the first resonance frequency is determined by the fixed capacitance element 450. The width of the parallel metal plates of the variable capacitance element 450 is set to be parallel to the fixed capacitance element 440 in accordance with the relational expression 1 in order to make the capacitance of the variable capacitance element 450 much smaller than the capacitance of the fixed capacitance element 440. [ The distance between the parallel metal plates of the variable capacitance element 450 may be much larger than the distance between the parallel metal plates of the fixed capacitance element 440. In addition, (At this time, decreasing the width of the metal plates or increasing the distance of the metal plates means that the effect of narrowing the width of the metal plates or increasing the distance of the metal plates on the equivalent circuit occurs. The concrete method may vary.)

The fixed capacitance element 440 has no change in capacitance even if manure is present in the diaper. Therefore, when the manure is present in the diaper, only the capacitance of the variable capacitance element 450 is changed, so that it is possible to reduce the width at which the resonance frequency changes by manure as compared with the conventional manure detection apparatus.

For example, if manure is present in the diaper and the permittivity of the peripheral dielectric material of the variable capacitance element 450 is increased by 100 times, the capacitance of the variable capacitance element 450 increases by 100 times to 100 (nF) The resonance frequency in the case where manure is present is about 4799 Hz according to the relational expression (1). When the capacitance of the variable capacitance element 450 is increased by 100 times due to the presence of the fixed capacitance element 440, the conventional manure detection apparatus has a 90% reduction in the magnitude of the resonance frequency, There is a 4.59% reduction in manure detection. Therefore, even if the range of the frequency sweep for measuring the resonance frequency is reduced, both the resonance frequency before and after the defecation can be measured, and the manure detection speed can be improved.

As another example, when the variable coffee saturation element is designed to refer to an absorber, if the manure is present in the diaper and the permittivity of the absorber of the variable capacitance element 450 is increased by a factor of 100, the capacitance of the variable capacitance element 450 is increased by a factor of 100 (NF), the resonance frequency when the manure is present in the diaper is about 4799 Hz according to the relational expression (1). When the dielectric constant of the variable capacitance element 450 is increased by 100 times due to the presence of the fixed capacitance element 440, the size of the resonance frequency of the conventional manure detection apparatus is reduced by 90%, while in the conventional manure detection apparatus, There is a 4.59% reduction in manure detection. Therefore, even if the range of the frequency sweep for measuring the resonance frequency is reduced, both the resonance frequency before and after the defecation can be measured, and the manure detection speed can be improved.

The fixed capacitance element 440 can be used to set the first resonance frequency by making the magnitude of the fundamental capacitance of the variable capacitance element 450 much smaller than the magnitude of the fundamental capacitance of the fixed capacitance element 440, , And the variable capacitance element 450 can be used to determine the second resonance frequency.

The manure detection reader 460 may be a separate device for detecting manure, but may be a mobile device such as a smart phone, a PDA, a tablet PC, etc. having the functions described above.

5 is an example for explaining a manure detection apparatus according to an embodiment.

Referring to FIG. 5, the variable capacitance element 550 may further include an absorber 510 that absorbs manure. The absorber 510 may be positioned between the parallel metal plates of the variable capacitance element 550.

The 'spaced-apart metal plates' in the present invention include substantially parallel metal plates, as well as parallel planar metal plates as well as parallel coaxial cylindrical metal plates, metal plates spaced apart from one another in roll form, And may include any type of metal plates that may have capacitances, such as metal plates of any shape.

The presence of an absorber between two metal plates means that the absorber is located where it can affect the capacitance formed by the two metal plates. That is, not only when the absorber exists in the space between the metal plates, but also when the absorber exists around each metal plate and can affect the capacitance.

The absorbent body 510 may extend outside the parallel metal plate to absorb manure in the diaper well. For example, even if the manure is located remotely from the variable capacitor element 550, the manure absorbed by the absorber portion extending outside the parallel metal plate can reach the absorber portion between the parallel metal plates, To help change the permittivity.

The variable capacitance element 550 may be exposed to the manure without a separate insulation part because it is a part that must be affected by manure.

In one example, if the manure directly touches the variable capacitance element 550, it may cause unexpected changes in parasitic capacitance or inductance due to conduction properties of manure, or parasitic resistance components may occur, The plate portion can be insulated or waterproofed.

In one example, at least a portion of the resonant circuit other than the absorber 510 may be insulated or waterproofed to prevent at least a portion of the resonant circuit portion other than the absorber 510 from being affected by the manure. The fixed capacitance element 540 may be integrally connected to the variable capacitance element 550, as shown in FIG. In this case, since the permittivity of the fixed capacitance element 540 should not be changed when the absorber 510 between the variable capacitance elements 550 absorbs the manure, there is a gap between the fixed capacitance element 540 and the variable capacitance element 550, (520) may be present. That is, reliability of the dielectric constant of the fixed capacitance element 540 can be maintained through the separator 520.

When the absorber 510 absorbs and expands the manure to expand the distance between the parallel metal plates, the capacitance of the variable capacitance element 550 can be reduced by the relational expression (1). The distance between the metal plates due to the expansion of the absorber 510 can be increased in consideration of the rate of expansion of the absorber 510, the manure absorption rate or the degree to which the two parallel metal plates withstand the expansion of the absorber 510, If the distance between one metal plate increases by a factor of two, the dielectric constant increases several tens of times and the overall capacitance increases.

In order to emphasize that there is a dielectric between the parallel metal plates of the fixed capacitance element 540, the variable capacitance element 550 is the only portion where the dielectric constant changes in the present invention, And the dielectric is omitted.

Referring to FIG. 6, the fixed capacitance element 540 and the variable capacitance element 550 are electrically connected by a connection portion 610. Unlike the case where the fixed capacitance element 540 and the variable capacitance element 550 are located close to each other and unlike the intention of the absorber 510 to absorb manure to change only the permittivity of the variable capacitance element 550, The element 540 may also be affected by manure to change its dielectric constant. In order to prevent this, the inductance element 530 and the fixed capacitance element 540 may be located far away from the variable capacitance element 550 and the manure discharge position so as not to be affected by manure. In one example, at least a portion of the resonant circuit other than the absorber 510 may be waterproofed to prevent at least a portion of the resonant circuit portion other than the absorber 510 from being affected by the manure.

Figs. 7 to 13 are views for explaining the structure of a capacitor element.

7 shows a capacitance element having a structure in which cylindrical plates are arranged in parallel. Referring to FIG. 7, two

cylindrical plates

710 and 720 having different diameters may be arranged parallel to each other.

8 shows a capacitance element having a roll-shaped structure. Referring to FIG. 8, at least two

plates

810 and 820 may have alternately coiled shapes.

9 shows a capacitance element having a structure in which

metal plates

910 and 920 having arbitrary curved surfaces are arranged in parallel, FIG. 10 shows a capacitance element having a bent parallel plate structure including two

metal plates

1010 and 1020, Fig. 11 shows a capacitance element including a thick metal plate 1110 and a bent plate 1120, Fig. 12 shows a capacitance element including a thin metal plate 1210 and a bent plate 1220, Fig. Fig. 8 is a view for explaining a capacitance element. Fig.

Fig. 13 is a view for explaining a capacitance element having a concavo-convex shape (finger shape). The capacitance can be controlled by using the gap (G), the end gap (G _E ), the width (W), the length (L), and the number of fingers as variables. The irregular-shaped capacitance element shown in FIG. 13 may also be referred to as an interdigital capacitor.

Referring to FIG. 14, the manure detector of the present invention does not include a separate absorber. When the manure is absorbed by the

absorbers

1410 and 1420 of the diaper, the dielectric constant of the

absorbers

1410 and 1420 of the diaper changes Occurs. The change in the dielectric constant of the

absorbers

1410 and 1420 of the diaper results in a change in the capacitance of the interdigital capacitor 1430 used as the variable capacitor. The manure detector of the present invention can sense the changed capacitance of the interdigital capacitor 1430.

Fig. 15 shows an equivalent circuit for the embodiment shown in Fig. 15, the interdigital capacitor 1430 is equivalently represented as the variable capacitor 1510 in Fig. 15, and the

absorbers

1410 and 1420 of the diaper are connected to the dielectric 1520 of the variable capacitor 1510 in an equivalent circuit And thus the change in the dielectric constant of the

absorbers

1410 and 1420 of the diaper is caused by a change in the dielectric constant of the dielectric 1520 of the variable capacitor 1510 of the equivalent circuit.

Referring to FIG. 16, the manure detector of the present invention does not include a separate absorber. When the manure is absorbed by the

absorbers

1610 and 1620 of the diaper, the dielectric constant of the

absorbers

1610 and 1620 of the diaper changes Occurs. The change in the permittivity of the

absorbers

1610 and 1620 of the diaper results in a change in the capacitance of the parasitic capacitance of the inductor 1630 used as the variable capacitor. The manure detector of the present invention can sense the changed capacitance of the parasitic capacitance of the inductor 1630.

17 shows an equivalent circuit for the embodiment shown in Fig. 17, the parasitic capacitance of the inductor 1630 is equivalently represented as the variable capacitor 1710 of Fig. 17, and the

absorbers

1610 and 1620 of the diaper are connected to the dielectric (not shown) of the variable capacitor 1710 The change in the dielectric constant of the

wedge bodies

1610 and 1620 of the diaper is caused by the change in the dielectric constant of the dielectric 1720 of the variable capacitor 1710 of the equivalent circuit.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

An apparatus for detecting manure in a diaper,

At least one inductance element;

At least one fixed capacitance element configured so that capacitance does not change even if manure is present in the diaper; And

At least one variable capacitance element electrically connected to the at least one fixed capacitance element and arranged such that capacitance changes when manure is present in the diaper;

Including the

Wherein at least one first resonant frequency is determined based on the at least one inductance element, the at least one fixed capacitance element and the at least one variable capacitance element.
The method according to claim 1,

The at least one variable capacitance element

An absorber for absorbing manure to change a capacitance of the at least one variable capacitance element; And

At least one spaced conductor < RTI ID = 0.0 >

Wherein the manure detection device comprises:
3. The method of claim 2,

The at least one variable capacitance element

Further comprising at least one insulating layer between the absorber and the at least one conductor to prevent direct exposure of the conductors to the manure absorbed by the absorber.
The method according to claim 1,

The capacitance of the at least one variable capacitance element changes when manure is present in the diaper,

At least one second resonant frequency is determined based on the at least one inductance element, the at least one fixed capacitance element and the at least one variable capacitance element whose capacitance is changed,

Wherein the at least one first resonant frequency and the at least one second resonant frequency are different from each other.
A power source for generating a first alternating magnetic field whose frequency changes in order to induce an electromotive force in the manure detecting device according to any one of claims 1 to 4;

A sensor unit for sensing a parameter related to a second alternating magnetic field generated by inducing the electromotive force by the manure detection device;

A controller for determining whether or not manure is present based on parameters related to a second alternating magnetic field sensed by the sensor; And

An output unit for informing the user whether or not the manure is present;

A manure detection reader.
6. The method of claim 5,

The power supply unit,

And generates a first alternating magnetic field whose frequency varies within a frequency band including the at least one first resonance frequency and the at least one second resonance frequency.
6. The method of claim 5,

Wherein the parameter comprises:

Wherein the frequency is an amplitude or an impedance of an induction current or induction voltage for each frequency.
6. The method of claim 5,

Wherein,

Wherein the controller determines the resonance frequency based on the parameter value and compares the resonance frequency with at least one first resonance frequency or at least one second resonance frequency to determine whether or not manure is present.
6. The method of claim 5,

Wherein,

Determining a resonance frequency before the presence of at least one manure and a resonance frequency after the presence of at least one manure based on the parameter value and determining a resonance frequency based on the resonance frequency before the presence of the at least one manure and after the presence of the at least one manure Thereby determining whether or not manure is present.
An apparatus for detecting the presence of a substance of interest,

At least one fixed capacitance element configured so that capacitance does not change even in the presence of a target material; And

At least one variable capacitance element electrically connected to the at least one fixed capacitance element and arranged such that capacitance changes when manure is present in the diaper;

Including the

Wherein at least one first resonant frequency is determined based on the at least one fixed capacitance element and the at least one variable capacitance element.