JP2001289806A - Excretion detecting method and apparatus therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the fatigue of a gas sensor by detecting urination and defecation by being distinguished. SOLUTION: Air (internal air) from a diaper cover 2 and outside air are guided alternately into a gas sensor 4 to detect defecation from increase in signal of the gas sensor 4 within the outside air.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to the detection of excretion.

[0002]

2. Description of the Related Art The inventors have been studying the detection of excretion by sucking the atmosphere in a diaper and guiding it to a gas sensor. In this process, it was found that the signal width was different between defecation and urination (Japanese Patent Laid-Open No. Hei 10-192324). However, it has been found that in the detection based on the peak width, urination and defecation are not completely distinguished, and that if the detection of excretion is continued, the gas sensor becomes fatigued and a satisfactory signal cannot be obtained.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to prevent the gas sensor from being fatigued due to the continuous detection of excretion. An additional object of the present invention is to provide a new method for detecting defecation. An additional object of the present invention is to detect both urination and defecation separately. An additional object of the invention according to claims 8 and 9 is to increase the sensitivity of the gas sensor to defecation. An additional object of the invention of claim 10 is to prevent the excretion odor from being trapped in the room in advance. An additional object of the present invention is to prevent a malfunction due to an increase in indoor gas concentration or the like.

[0004]

According to the present invention, the gas sensor is alternately exposed to an atmosphere near the diaper of the care recipient and to an atmosphere other than the diaper, and the excretion is obtained from the signal of the gas sensor while periodically switching the atmosphere touched by the gas sensor. A method for detecting excretion is provided (claim 1).

[0005] The present invention also provides a method for changing the atmosphere touched by the gas sensor between the atmosphere near the diaper of the care recipient and the other atmosphere, while increasing the signal of the gas sensor in the other atmosphere. An excretion detection method for detecting defecation is provided (claim 2). In the detection of defecation, a decrease in the return speed from the gas sensor signal in the inside air to the gas sensor signal in the outside air may be obtained, and this may be used as an index of defecation. For example, an increase in the sensor signal in the open air
This is an indication that the speed of return from the sensor signal in the inside air to the sensor signal in the outside air is reduced. The rate of change of the sensor signal when switching to outside air also indicates the speed at which the sensor signal returns from inside air to outside air. Further, extending the time of exposure to the outside air so that the sensor signal in the outside air becomes almost constant,
To shorten the time of exposure to shy atmosphere, or when introducing shy atmosphere,
If you change the dilution ratio between inside air and outside air,
The time of exposure to the outside air, the time of exposure to the inside air, the dilution ratio, etc.
It indicates the return speed from the gas sensor signal in the inside air to the gas sensor signal in the outside air. Preferably, urination is detected from the signal of the gas sensor in the atmosphere near the diaper.

According to the present invention, there is provided a means for alternately sucking an atmosphere in the vicinity of a diaper of a care recipient and another atmosphere to guide the atmosphere to a gas sensor, and periodically switching an atmosphere touched by the gas sensor by the means. And a means for detecting excretion from the signal of the gas sensor.

Further, according to the present invention, means for changing the atmosphere touched by the gas sensor between the atmosphere near the diaper of the care recipient and the other atmosphere, and the signal of the gas sensor in the other atmosphere are provided. Means for detecting defecation from the increase is provided (claim 6). In the detection of defecation, means is provided for determining a decrease in the return speed from the gas sensor signal in the inside air to the gas sensor signal in the outside air, and defecation is detected from the output of the means (claim 7). For example, an increase in the sensor signal in the outside air indicates that the speed of return from the sensor signal in the inside air to the sensor signal in the outside air has decreased. The rate of change of the sensor signal when switching to outside air also indicates the speed at which the sensor signal returns from inside air to outside air. In addition, extend the exposure time to the outside air, shorten the exposure time to the inside air, or change the dilution ratio between the inside air and the outside air when introducing the inside air so that the sensor signal in the outside air becomes almost constant. In this case, the time of exposure to the outside air, the time of exposure to the inside air, the dilution ratio, and the like indicate the rate of return from the gas sensor signal in the inside air to the gas sensor signal in the outside air. Preferably, a heater is provided in the gas sensor, and the heater power is periodically converted so that the gas sensor temperature is periodically changed. Preferably, the gas sensor is a polymer odor sensor. Preferably, an air conditioning request signal is output based on the detection of excretion. Also preferably, by comparing the signal of the gas sensor in an atmosphere near the diaper and the signal in other atmospheres, to detect an error from a predetermined condition, for example, that the outside air signal is larger than the inside air signal, Means are provided.

[0008] Here, the atmosphere near the diaper of the care recipient means the atmosphere inside the diaper, the atmosphere inside the blanket or futon in the bed at a position corresponding to the buttocks, the waist, or the like. Hereinafter, the atmosphere near the diaper is referred to as “atmosphere”, and the other atmosphere is referred to as “atmosphere”. The outside air may be room air sampled from the outside of the bed or the like, or may be air purified by an ozone deodorizer, an activated carbon deodorizer, a photocatalytic deodorizer, or the like. In this case, the atmosphere inside the diaper may be deodorized to be the outside air. The inside air may be diluted with outside air from the beginning and brought into contact with the gas sensor.

One cycle of the atmosphere switching is, for example, 10 seconds to 10 minutes, and the ratio of contact with the inside air and the ratio of contact with the outside air are, for example, about 2: 1 to 1:10 for inside: outside.
However, the cycle may be variable depending on the situation. The signal of the gas sensor is increased due to odor, and the magnitude of the signal may be opposite to the magnitude of the voltage representing the signal. The defecation is detected only when the increase in the gas sensor signal in the outside air or when both the increase in the inside air and the increase in the outside air are satisfied. The signal in the inside air or the signal in the outside air may be reconstructed by, for example, Fourier-transforming the sensor signal and combining a DC component with a primary component synchronized with switching between the inside and outside air.

It is preferable that the temperature of the gas sensor is periodically changed in order to increase the sensitivity to defecation. In particular, the gas sensor is heated in a pulsed manner for a short time (1 ms to 10 seconds), and the pulse heating time is set to one.
It is preferable to cool without applying power for 0 times or more. When excretion is detected, for example, it is preferable to accumulate the number of times of urination detection or detect defecation, output a signal for air conditioning, operate a deodorizer for indoor air, or encourage ventilation. When alcohol or the like is used indoors, the sensor signal in the outside air may exceed the sensor signal in the inside air, for example. In such a case, it is preferable to compare these signals and detect a defect when a predetermined condition is satisfied.

[0011]

According to the present invention, the gas sensor is exposed to the atmosphere near the diaper of the care recipient and the other atmosphere, and the atmosphere touched by the gas sensor is switched. With this configuration, it is possible to prevent abnormalities in the sensor signal when the gas sensor is continuously exposed to the atmosphere near the diaper for a long time. The reason why such an effect is obtained is not clear, but it is considered to be because it is possible to prevent odorous substances and the like contained in the atmosphere near the diaper from adhering and accumulating on the gas sensor.

If the gas sensor is alternately exposed to an atmosphere near the diaper (inside air) and another atmosphere (outside air), the signal in the inside air increases when urinating, and the signal in the outside air does not increase much. On the other hand, at the time of defecation, the sensor signal increases in both the inside air and the outside air, and the defecation can be detected from the increase in the sensor signal in the outside air.
3, 6, 7). Further, an increase in the sensor signal in the inside air corresponds to urination or defecation. Here, excretion of the urine can be detected except for an increase in the sensor signal in the outside air.
It should be noted that the detection of urination is not particularly meaningful in detecting only urination, but may be detected as urination or defecation (claim 4).

The gas sensor to be used is optional, but preferably the temperature of the gas sensor is changed periodically. Particularly preferably, the gas sensor is heated in a pulsed manner, and is left to cool during the rest of the time. . A gas sensor using a temperature change generally has high sensitivity to odor associated with defecation in a low temperature range, and a pulse heating type gas sensor generally has high sensitivity to odor associated with defecation near room temperature. Further, if an odor sensor utilizing the attachment of an odor substance to a polymer or the like is used, defecation can be easily detected. Such an odor sensor is, for example, provided with a polymer film on the surface of a quartz oscillator, and detects a change in weight due to the attachment of odor molecules to the film.

When urination or defecation is performed, the odor gradually gets trapped in the room. Therefore, when urination or defecation is detected, if an air conditioning request signal for requesting operation of ventilation and deodorizer under appropriate conditions is output to the outside, it is possible to prevent odors from being trapped in the room. When indoor air is used as outside air, if alcohol or the like is used indoors,
It becomes difficult to detect defecation. Therefore, an error is detected by satisfying a predetermined condition such that the sensor signal in the outside air has reached a predetermined ratio or more with respect to the sensor signal in the inside air. Here, the predetermined ratio may be changed according to the value of the sensor signal in the inside air or the outside air, or the like.

[0015]

1 to 18 show an embodiment and its modifications. FIG. 1 shows a block configuration of the excretion detecting device according to the embodiment. Numeral 2 denotes a diaper cover, and a diaper pad is mounted inside the diaper cover to be worn by bedridden nurses or the like. The diaper is sucked through the diaper cover 2.
Alternatively, the collection bag 3 or the like may be arranged at a position corresponding to the buttocks or waist in the bed, and the atmosphere may be sucked from the porous collection bag 3.

Reference numeral 4 denotes a gas sensor, which uses a gas sensor in which a metal oxide semiconductor is heated by a heater. However, instead of such a gas sensor, a sensor or the like in which a gas-adsorbing polymer is provided on the surface of a quartz oscillator or the like to detect a change in weight due to adsorption of odor molecules may be used. Reference numeral 6 denotes a valve, 8 denotes a suction pump, and 10 denotes a tube. By switching the direction of the valve 6, the atmosphere inside the diaper and the other atmosphere (here, room air).
Is sucked by switching, for example, every one minute in a two-minute cycle.

Reference numeral 12 denotes a microcomputer, and 14 denotes A
A D converter 16 is a timer for operating the valve 6, and its signal is used as a Timer signal. Reference numeral 18 denotes an inside air signal storage unit which stores an appropriate number of signals in the inside air or a value serving as a baseline of these signals.
Reference numeral 20 denotes an outside air signal storage unit which stores a signal in the outside air for an appropriate number of times, or stores a baseline of a sensor signal in the outside air. Detection of the baseline of a gas sensor signal is known in the field of air purifier control and the like. For example, when the actual gas sensor signal is larger than the baseline, the baseline is added. When the actual gas sensor signal is smaller than the baseline, the baseline is made to match the gas sensor signal. In this way, a baseline along the bottom of the gas sensor signal is obtained.
Various other methods for calculating the baseline are known.

Reference numeral 22 denotes a urination detection unit, which detects either urination or defecation without distinguishing between the urine and defecation since the signal of the gas sensor in the inside air has increased with respect to the baseline. Reference numeral 24 denotes a bowel movement detection unit, which detects bowel movement, for example, when the gas sensor signal in the outside air has increased by a predetermined ratio or more with respect to the baseline. In the detection of defecation, it may be determined that the sensor signal has increased with respect to the base line by a predetermined ratio or more in the inside air or the outside air.

Reference numeral 26 denotes a failure detection unit which detects an error when the sensor signal in the outside air is equal to or larger than the sensor signal in the inside air and the sensor signal in the inside air is equal to or less than a predetermined value. This corresponds to a case where the atmosphere in the diaper is not contaminated and the room air is contaminated for some reason. Instead of detecting the error by comparing the sensor signals of the outside air and the inside air, a second gas sensor 32 may be provided to monitor the contamination of the indoor air.

Reference numeral 30 denotes a reset unit which resets each time the diaper is replaced, thereby resetting the respective baselines stored in the inside air signal storage unit 18 and the outside air signal storage unit 20. The reset may be performed manually when the nurse changes the diaper, or may be automatically reset using a sudden change in the temperature in the diaper.

Reference numeral 28 denotes an external output, which outputs four kinds of signals to the outside: defecation, urination, air-conditioning request, and error. These signals are output by cable or infrared communication. And for example, defecation and urination are displayed by LED etc.,
The air conditioning request signal drives a ventilation fan, a deodorizer, and the like when they are provided in the room.

In the embodiment of FIG. 1, indoor air is used as the outside air. However, the air inside the diaper may be purified by some method and used as the outside air. 2 and 3 show such an example. In FIG. 2, reference numeral 40 denotes an ozone deodorizer, which may be another deodorizer. The ozone deodorizer 40 is turned on / off every minute, for example, by a Timer signal from the microcomputer 12. The signal of the gas sensor when the ozone deodorizer 40 is turned on may be regarded as a signal of the outside air.

In the modified example of FIG. 3, reference numeral 42 denotes an activated carbon deodorizer, and a photocatalytic deodorizer may be used in place of the activated carbon deodorizer. The difference from the ozone deodorizer 40 is not very suitable for on / off control. On the point. In FIG. 3, reference numeral 7 denotes a new valve, which drives the valves 6 and 7 by a Timer signal from the microcomputer 12. And activated carbon deodorizer 42
Is led to the gas sensor 4 and the atmosphere in the diaper purified by the activated carbon deodorizer 42 is led to the gas sensor 4 alternately.

Here, an example of numerical conditions will be described. The switching cycle of the atmosphere is, for example, 10 seconds to 10 minutes, with the total of the time of exposure to the inside air and the time of exposure to the outside air as one cycle.
Preferably, the period is 30 seconds to 5 minutes, and in the embodiment, the period is 2 minutes each. In addition, the ratio of contact with the inside air and the ratio of contact with the outside air are such that the greater the ratio of contact with the outside air, the less the fatigue of the gas sensor 4. Therefore, the ratio of the ratio of contact with the inside air and the ratio of contact with the outside air is, for example, about 2: 1 to 1:10. And preferably about 1: 1 to 1: 3.

FIG. 4 shows the structure of the gas sensor 4 used. 50 is a substrate of alumina or the like, 52 is a heater, 54
Is an insulating film, and 56 is a metal oxide semiconductor using SnO2. When the driving waveform of the gas sensor 4 is shown in FIG. 5, the heater voltage is shown by a solid line. For example, the heater 4 is turned on every 1 second for 14 msec, and the metal oxide semiconductor 56 is heated to a maximum temperature of 300 to 300 msec.
Heat to about 400 ° C. Accordingly, the output Vout of the gas sensor 4 changes as shown by a broken line in FIG. 5, and for example, a gas sensor signal immediately before pulse heating is sampled.

FIG. 6 shows a gas sensor 60 according to a modification.
2 is a bead of a metal oxide semiconductor such as SnO2, 64 is a heater coil, and 66 is a center electrode. Gas sensor 6
7, pulse driving is performed as shown in FIG. 7, and for example, power is applied to the heater coil 64 for 5 seconds for 60 seconds, and the output Vout consisting of the electrical conductivity between the heater coil 64 and the center electrode 66 is thereby changed as shown in FIG. It changes like a broken line. This output is sampled, for example, immediately before pulse heating. The time width of the pulse heating is preferably from 1 ms to 10 seconds, more preferably from 10 ms to 5 seconds, and the width of the time for allowing the heater to cool without applying power is preferably one pulse heating time.
0 times or more. And, although not particularly limited,
The gas sensor signal is sampled when power is not applied to the heater.

FIG. 8 shows a signal waveform of the gas sensor accompanying the switching between the inside and outside air. FIG. 8 (1) shows the switching of atmosphere between inside air and outside air. At the time of (2) urination, the signal in outside air does not increase so much, and the signal in inside air increases. On the other hand, at the time of defecation in (3), both the signal in the outside air and the signal in the inside air increase. The sampling of the signal in the outside air may be performed, for example, by Fourier-transforming the waveform of FIG. 8 and reconstructing the sum of the absolute values of the R1 and I1 components synchronized with the switching of the DC component and the atmosphere.

FIGS. 9 to 11 show changes in sensor signals between inside air and outside air for 24 hours. Unless otherwise specified, the gas sensor used is the gas sensor shown in FIG. 4 and the driving conditions are the same as those described with reference to FIG. The sampling of the sensor signals of the inside air and the outside air was performed immediately before the switching of the atmosphere. "Urine pad exchange" and the like in the figure indicate that the urine pad has been exchanged, and the quantity such as "+270 g" is an increase in the weight of the urine pad. The number of times of exchanging urine pats, diapers, etc. was eight in the range of FIGS. 9 to 11, of which three defecations were present. When there is no defecation, a peak is seen in the inside air, but almost no peak is seen in the outside air. This means that the sensor signal of the outside air hardly increases only by urination. When defecation occurs, both the inside air sensor signal and the outside air sensor signal increase. Therefore, defecation can be detected from an increase in the sensor signal in the outside air.

9 to 11, no abnormality is found in the sensor signal, and no fatigue of the gas sensor occurs. When the gas sensor was exposed alternately to inside air and outside air, no fatigue of the gas sensor was observed in a range of continuous use for about two weeks. Since the temperature, humidity, and the like in the diaper change, a baseline is provided along the bottom of the past sensor signal, and urination and defecation are detected in accordance with an increase from the baseline. Here, when there is bowel movement, the sensor signal does not readily decrease in both inside and outside air even if the diaper is replaced. Therefore, it is preferable to update the base by operating the reset unit 30 each time the diaper is changed.

FIG. 12 shows the waveform of the sensor signal for the same care recipient for 8 hours on another day. During this period, there was no defecation and only urination. Although many strong peaks occur in the inside air, there are almost no peaks in the outside air, and urination and defecation can be distinguished.

When a heater is provided, the gas sensor used preferably preferably changes the sensor temperature periodically.
More preferably, it is heated in a pulsed manner, and the others are allowed to cool to room temperature. 4 using a gas sensor similar to that of FIG. 4 and fixing the temperature of the metal oxide semiconductor to 400 ° C.
FIGS. 13 and 14 show waveforms of about 16 hours with the gas sensor of FIG. The right end of FIG. 13 is connected to the left end of FIG. During this time, the number of defecations is three, and there is another urination. In the pulse heating type gas sensor, the sensitivity to defecation is high, and the sensor signal in the outside air increases during defecation, so that defecation can be detected. In contrast, a sensor whose operating temperature is fixed at 400 ° C. has low sensitivity to defecation,
The increase in the gas sensor signal at the time of defecation is not always clear. Further, there is a case where the sensor signal in the outside air increases despite no defecation.

This is not limited to the cases of FIGS. 13 and 14, but is generally observed. The pulse heating type gas sensor has higher sensitivity to defecation than the fixed temperature type gas sensor, The increase in the outside air signal was also remarkable. Although the embodiment shows a metal oxide semiconductor gas sensor, defecation could be detected in the same manner in a quartz oscillator sensor having a polymer film for adsorbing hydrogen sulfide gas on the surface of the quartz oscillator.

When the gas sensor was continuously exposed to the inside air, fatigue of the gas sensor was observed. This fatigue was remarkable in the pulse heating type gas sensor, and was not so remarkable in the gas sensor heated to a constant temperature such as 400 ° C. 15 and 16 show waveforms when the metal oxide semiconductor gas sensor is used while being fixed at 400 ° C., and FIG. 16 is a waveform 48 hours after FIG. 15, in which the gas sensor is continuously exposed only to the inside air. Was. Baseline of gas sensor signal is 300-400
mV, which has not changed after 48 hours. However, in some cases, even with a gas sensor heated to a constant temperature, the baseline of the sensor signal increases in some cases and does not return as it is.

FIGS. 17 and 18 show operation waveforms of the pulse heating type gas sensor of FIG. 4, and FIG.
With the waveform after time, only inside air was continuously sucked during this time.
In FIG. 17, the baseline of the gas sensor signal is around 1V, and in FIG. 18, even if the diaper is replaced after a large amount of bowel movements, the gas sensor signal remains stuck at around 4V for several hours, and no meaningful detection is performed. It is now possible. Such a phenomenon is called gas sensor fatigue. Returning to FIG. 9 to FIG. 12, when the inside air and the outside air were brought into contact with the gas sensor 4 alternately, no fatigue of the gas sensor occurred.

FIG. 19 shows a modification in which the accuracy of defecation detection is increased. Initially, for example, switching between inside air and outside air every minute, and when the gas sensor output in outside air exceeds the threshold value, the atmosphere is switched to outside air, for example, only 5 to 10 minutes are brought into contact with outside air, and the heating condition of the sensor is changed. And heat clean. Next, switching between inside air and outside air is restarted, and defecation is detected from a sensor signal in the outside air thereafter. If you want to further increase the accuracy here, after switching between inside air and outside air again,
For example, if the threshold is not reached within 10 minutes to 30 minutes, urination is determined. Instead of limiting the time until the threshold value is reached after switching between inside air / outside air and restarting switching between inside air / outside air, the rate of increase of the sensor signal in outside air after restarting switching between inside air / outside air is determined by using a timer. Is also good.

In this manner, the fatigue of the sensor can be prevented by changing the atmosphere to the outside air and heat cleaning, and the sensor signal in the outside air after the resumption of the switching between the inside air and the outside air can be obtained.
Defecation can be reliably distinguished from urination and detected.

FIG. 20 shows a modification of updating the reference value in the inside air or the outside air. The sensor signals of inside air and outside air are close,
The fact that they are both small indicates that there is neither urination nor defecation, and there is no other noise. The fact that the sensor signals of the inside air and the outside air are both small can be indirectly detected by being within a predetermined range from the previous reference value. Therefore, when the difference or ratio of the sensor signal between the inside air and the outside air is within a predetermined range and within a predetermined range from the previous reference value or the like, the reference values of the inside air and the outside air are sampled, or only the inside air is sampled. However, it is preferable to sample the reference value. It is not necessary to update the reference value by 100% with the sampled value.
Statistical processing may be performed.

A feature in the detection of defecation is an increase in the gas sensor signal in the outside air. This can be expressed as that the response of the gas sensor signal to the change of the atmosphere from the inside air to the outside air is delayed, and the restoration of the sensor signal from the inside air to the outside air is delayed.
In other words, the responsiveness of the gas sensor signal to the change in the atmosphere from the inside air to the outside air is a characteristic of defecation. In order to detect the delay of the return, in addition to directly using the sensor signal in the outside air, a rate of change of the sensor signal due to the change from inside air to outside air, preferably a rate of change of the logarithm of the sensor signal, may be used. In order to keep the sensor signal in the outside air in a predetermined range with respect to the base value, how long the outside air introduction time should be or how short the inside air introduction time should be Further, how much the inside air may be diluted with the outside air and introduced may be used.
These are examples in which a sensor signal in the outside air is indirectly used.

As is apparent from the above description, periodically switching the atmosphere does not mean that the switching cycle is constant, but the cycle may be variable according to the situation.
"Alternating between inside air and outside air" does not preclude introducing a third atmosphere in between. The inside air may be diluted with outside air and guided to the outside, or the mixture ratio of the inside air and outside air may be changed periodically and guided to the gas sensor.

Although the embodiments have been described with reference to specific examples, the invention is not limited to these. In particular, the material and structure of the gas sensor are arbitrary, and a gas sensor that changes the temperature more than a continuous heating type, particularly a metal oxide semiconductor gas sensor, is preferable.
Further, the one in which the metal oxide semiconductor gas sensor is pulse-heated is most preferable. Two or more gas sensors may be used in combination. Further, the material and the like of the tube 10 are arbitrary, and it is arbitrary whether the atmosphere is sucked directly from the inside of the diaper or the air in the bed around the diaper is sucked. Although the inside air and the outside air are alternately guided, for example, the outside air may be constantly guided to the gas sensor, and the inside air may be intermittently sampled, mixed with the outside air, and guided to the gas sensor.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an arrangement of an embodiment.

FIG. 2 is a main part block diagram of a first modified example.

FIG. 3 is a block diagram of a main part of a second modified example.

FIG. 4 is a sectional view of a gas sensor used in the embodiment.

5 is an operation waveform diagram of the gas sensor of FIG.

FIG. 6 is a plan view of a gas sensor used in a modification.

FIG. 7 is an operation waveform diagram of the gas sensor of FIG. 6;

FIG. 8 is a waveform diagram showing changes in inside air / outside air and signal waveforms at the time of urination and defecation.

FIG. 9 is a characteristic diagram showing waveforms of inside air / outside air for 8 hours.

FIG. 10 is a characteristic diagram showing an 8-hour waveform following FIG. 9;

FIG. 11 is a characteristic diagram showing a waveform for 8 hours following FIG. 10;

FIG. 12 is a characteristic diagram showing a waveform for urination.

FIG. 13 is a characteristic diagram showing waveforms in the inside air / outside air between the pulse heating sensor and the constant temperature heating sensor.

FIG. 14 is a characteristic diagram showing a waveform following FIG. 13;

FIG. 15 is a characteristic diagram showing a waveform when the constant temperature heating sensor is exposed only to the inside air.

FIG. 16 is a characteristic diagram showing a waveform 48 hours after FIG. 15;

FIG. 17 is a characteristic diagram showing a waveform when the pulse heating sensor is exposed only to inside air.

FIG. 18 is a characteristic diagram showing a waveform 24 hours after FIG. 17;

FIG. 19 is a diagram showing detection of excretion in a modified example, wherein 1) shows the atmosphere of inside air / outside air and heat cleaning, and 2) switching between heat cleaning and outside air hold by increasing the outside air output, and switching between inside and outside air. , Detection of a timeout by a timer, and detection of an increasing gradient of a signal in the outside air after resumption of switching between inside and outside air.

FIG. 20 shows a modified example of updating a reference value for inside air or outside air, in which a difference between signals of inside air and outside air is small and signals of inside air and outside air are within a predetermined range as compared with a previous reference value. Shows that the reference value is updated.

[Explanation of symbols]

 2 Diaper cover 3 Collection bag 4 Gas sensor 6, 7 Valve 8 Suction pump 10 Tube 12 Microcomputer 14 AD converter 16 Timer 18 Inside air signal storage unit 20 Outside air signal storage unit 22 Urination detection unit 24 Defecation detection unit 26 Failure detection unit 28 External Output 30 Reset unit 32 Second gas sensor 40 Ozone deodorizer 42 Activated carbon deodorizer 50 Substrate 52 Heater 54 Insulating film 56 Metal oxide semiconductor 60 Gas sensor 62 Metal oxide semiconductor bead 64 Heater coil 66 Center electrode

Continuation of the front page (72) Inventor Yo Kato 1-3-5 Senba Nishi, Minoh City Inside Figaro Giken Co., Ltd. (72) Inventor Tomohiro Kawaguchi 1-3-5 Senba Nishi Mino City Inside Figaro Giken Co., Ltd. (72) Inventor Yasuhiro Setoguchi 1-3-5 Senba Nishi, Minoh City Inside Figaro Giken Co., Ltd. (72) Inventor Tatsuya Funai 3-16-4 Ishimaru Minoh City Forevers Inc. F-term (reference) 2G046 AA34 BA01 BA02 BB02 BC03 BC04 BE02 BE03 DA05 DB03 DB07 DC09 DC14 DC16 DC17 DC18 EB06 FB02 FE03 FE39 4C098 AA09 CC01 CD08 CE05 CE06

Claims (11)

[Claims] 1. An excretion detector for exposing a gas sensor to an atmosphere in the vicinity of a diaper of a care recipient and another atmosphere, and periodically changing an atmosphere touched by the gas sensor, and detecting excretion from a signal of the gas sensor. Method. 2. The defecation is detected from an increase in the signal of the gas sensor in the other atmosphere while changing the atmosphere touched by the gas sensor between the atmosphere near the diaper of the care recipient and the other atmosphere. Excretion detection method. 3. The return speed of the gas sensor signal in the inside air to the gas sensor signal in the outside air while changing the atmosphere touched by the gas sensor between the atmosphere near the diaper of the care recipient and the other atmosphere. An excretion detection method that detects defecation from a drop. 4. The excretion detection method according to claim 2, wherein urination is detected from a signal of a gas sensor in an atmosphere near the diaper. 5. A means for alternately sucking and guiding a gas sensor to an atmosphere near a diaper of a care recipient and another atmosphere for detecting excretion from a signal of the gas sensor. And an excretion detecting device provided with means. 6. A means for changing the atmosphere touched by the gas sensor between the atmosphere near the diaper of the care recipient and the other atmosphere, and defecation from an increase in the signal of the gas sensor in the other atmosphere. Excretion detection device, comprising: means for detecting 7. A means for changing an atmosphere touched by a gas sensor between an atmosphere near a diaper of a cared person and other atmospheres, and a method for changing a gas sensor signal from inside air to a gas sensor signal from outside air. An excretion detection device provided with means for determining a decrease in the return speed and means for detecting defecation from the output of the means. 8. The gas sensor according to claim 6, wherein a heater is provided in the gas sensor, and the heater power is periodically changed to periodically change the gas sensor temperature.
Or the excretion detection device of 7. 9. The excretion detecting device according to claim 6, wherein the gas sensor is a high molecular smell sensor. 10. The excretion detection device according to claim 5, wherein an air conditioning request signal is output based on the detection of excretion. 11. A means for comparing a signal of a gas sensor in an atmosphere near a diaper with a signal of another atmosphere to detect an error under a predetermined condition is provided. An excretion detection device according to any one of 5 to 10.