Stress measurement system

Abstract

To provide a stress measurement system and a stress measurement method that are capable of measuring the stress level of a subject without taking time and effort.SOLUTION: A stress measurement system 1 comprises: a sensor unit 31 that detects a plurality of detection target gases based on substances contained in a specimen of a subject and outputs a plurality of detection values corresponding to respective detection results of the plurality of detection target gases; and a control unit that determines a stress level of the subject, based on a combination of the plurality of detection values. The substances contained in the specimen include a substance serving as a raw material for a brain neurotransmitter.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] (Cross - reference to related applications) This application claims the priority of Japanese Patent Application No. 2019 - 213551 (filed on November 26, 2019), and the entire disclosure of the said application is incorporated herein by reference for reference purposes.

[0002] This disclosure relates to a stress measurement system and a stress measurement method.

Background Art

[0003] Conventionally, as methods for measuring the stress state of a subject, evaluation based on cortisol in blood or the like, and evaluation based on changes in exhalation or heartbeat are known. Further, as another method, a stress measurement device that determines the stress of a speaker by using voice data of both parties during conversation has been proposed (for example, Patent Document 1 below).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

[0005] A stress measurement system according to one embodiment of the present disclosure includes a sensor unit that detects a plurality of detected gases based on substances contained in a specimen of a subject and outputs a plurality of detection values corresponding to the detection results of each of the plurality of detected gases, and a control unit that determines the degree of stress of the subject based on a combination of the plurality of detection values.

[0006] Also, a stress measurement method according to one embodiment of the present disclosure detects a plurality of detected gases and the concentration of each of the plurality of detected gases from a specimen of a subject, and determines the degree of stress of the subject based on a combination of the concentrations of the plurality of detected gases.

Brief Description of the Drawings

[0007]

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Embodiments for Carrying Out the Invention

[0008] Hereinafter, embodiments according to the present disclosure will be described with reference to the drawings. Each drawing is schematically shown.

[0009] [Configuration Example of Stress Measurement System] The stress measurement system 1 shown in FIG. 1 detects a gas based on a substance contained in a specimen of a subject, and determines the degree of stress of the subject based on the detection value. Here, the specimen of the subject is an object to be examined used for determining the degree of stress. The specimen of the subject can be, for example, a part of the subject's tissue or urine, etc., but in this embodiment, it is the subject's feces. Further, the stress measurement system 1 is also a gas detection system that detects a gas from a specimen for determining the degree of stress.

[0010] As shown in FIG. 1, the stress measurement system 1 is installed, for example, in a toilet bowl 2 for flushing. The toilet bowl 2 includes a toilet bowl 2A and a toilet seat 2B. The stress measurement system 1 may be installed at any location of the toilet bowl 2. As an example, the stress measurement system 1 may be arranged from between the toilet bowl 2A and the toilet seat 2B to the outside of the toilet bowl 2 as shown in FIG. 1. A part of the stress measurement system 1 may be embedded in the toilet seat 2B. Feces of the subject can be discharged into the toilet bowl 2A of the toilet bowl 2. The stress measurement system 1 can acquire, as a sample gas, a gas generated from the feces discharged into the toilet bowl 2A. The stress measurement system 1 can detect the concentrations, etc. of a plurality of gases based on a specific substance contained in the sample gas. The stress measurement system 1 can transmit the detection result and the determined degree of stress of the subject, etc. to the electronic device 3. Here, the specific substance is contained in feces and is a substance that is decomposed and excreted without being absorbed by the intestine as a raw material for neurotransmitters in the brain in the body. Details of the specific substance will be described later. Also, the housing 10, the first suction hole 20, the second suction hole 21, and the discharge path 22 will be described later.

[0011] The toilet 2 can be installed in a toilet room of a house or a hospital. Also, the electronic device 3 is, for example, a smartphone used by the subject. However, the electronic device 3 is not limited to a smartphone and may be any electronic device. The electronic device 3 may be inside the toilet room or outside the toilet room.

[0012] The electronic device 3 can receive the detection result from the stress measurement system 1 by wireless communication or wired communication. The electronic device 3 can display the received detection result on the display unit 3A. The display unit 3A may be configured to include a display capable of displaying characters and the like and a touch screen capable of detecting contact of a finger or the like of the user (subject). The display may be configured to include a display device such as a liquid crystal display (LCD), an organic EL display (OELD), or an inorganic EL display (IELD). The detection method of the touch screen may be any method such as a capacitance method, a resistive film method, a surface acoustic wave method (or ultrasonic method), an infrared method, an electromagnetic induction method, or a load detection method.

[0013] As shown in FIG. 2, the stress measurement system 1 includes a housing 10, a first suction hole 20, a second suction hole 21, a discharge path 22, flow paths 23, 24, a chamber 30, a first storage tank 40, a second storage tank 41, a first supply unit 50, a second supply unit 51, and a circuit board 60. The flow path 23 includes a flow path 23-1 and a flow path 23-2. The flow path 24 includes a flow path 24-1 and a flow path 24-2. The stress measurement system 1 may include a valve 20B and a valve 21B. The stress measurement system 1 may include valves 25, 26, a flow path 27, a flow path 28, and a third supply unit 52. The flow path 27 includes a flow path 27-1, a flow path 27-2, and a flow path 27-3.

[0014] As shown in FIG. 3, the circuit board 60 of the stress measurement system 1 includes a storage unit 61, a communication unit 62, and a control unit 64. The stress measurement system 1 may include a sensor unit 63. Further, the stress measurement system 1 may include a battery, a speaker, and the like.

[0015] The housing 10 houses various components of the stress measurement system 1. The housing 10 may be made of any material. For example, the housing 10 may be made of a material such as metal or resin.

[0016] As shown in FIG. 1, the first suction hole 20 can be exposed inside the toilet bowl 2A. A part of the first suction hole 20 may be embedded in the toilet seat 2B. The first suction hole 20 sucks the gas generated from the feces discharged into the toilet bowl 2A as a sample gas. The sample gas sucked by the first suction hole 20 is supplied to and stored in the first storage tank 40 via the valve 20B shown in FIG. 2. As shown in FIG. 1, one end of the first suction hole 20 may be directed inside the toilet bowl 2A. As shown in FIG. 2, the other end of the first suction hole 20 may be connected to the first storage tank 40. The first suction hole 20 may be composed of a tubular member such as a resin tube or a metal or glass pipe.

[0017] As shown in FIG. 2, a blower 20A may be provided outside the first suction hole 20. The blower 20A may be composed of a fan and a motor. The blower 20A is controlled by the control unit 64. When the motor is driven and the fan rotates, the sample gas is drawn into the vicinity of the first suction hole 20.

[0018] The valve 20B is located between the first suction hole 20, the first storage tank 40, and the flow path 28. The valve 20B includes a connection port connected to the first suction hole 20, a connection port connected to the inlet portion of the first storage tank 40, and a connection port connected to the flow path 28. The valve 20B may be composed of a valve such as electromagnetic drive, piezo drive, or motor drive.

[0019] By controlling the valve 20B by the control unit 64, the connection state between the first suction hole 20, the first storage tank 40, and the flow path 28 is switched. For example, the control unit 64 switches the connection state between them to a state where the first suction hole 20 and the first storage tank 40 are connected, a state where the first storage tank 40 and the flow path 28 are connected, or a state where the first suction hole 20, the first storage tank 40, and the flow path 28 are not connected to each other.

[0020] When the first suction hole 20 sucks the sample gas, the control unit 64 controls the valve 20B to make the state where the first suction hole 20 and the first storage tank 40 are connected. Further, when the sample gas is stored in the first storage tank 40, the control unit 64 controls the valve 20B to make the state where the first suction hole 20, the first storage tank 40, and the flow path 28 are not connected to each other. Since the first storage tank 40 is not connected to the first suction hole 20, the probability that the sample gas in the first storage tank 40 comes into contact with the outside air can be reduced.

[0021] As shown in FIG. 1, the second suction hole 21 may be exposed to the outside of the toilet bowl 2A. A part of the second suction hole 21 may be embedded in the toilet seat 2B. The second suction hole 21 sucks, for example, the air (environmental gas) in the toilet room outside the toilet bowl 2A as purge gas. The purge gas sucked by the second suction hole 21 is supplied to and stored in the second storage tank 41 via the valve 21B shown in FIG. 2. As shown in FIG. 1, one end of the second suction hole 21 may be directed to the outside of the toilet 2. As shown in FIG. 2, the other end of the second suction hole 21 may be connected to the second storage tank 41. The second suction hole 21 may be composed of a tubular member such as a resin tube or a metal or glass pipe.

[0022] As shown in FIG. 2, a blower 21A may be provided outside the second suction hole 21. The blower 21A may be configured to include a fan and a motor. The blower 21A is controlled by the control unit 64. When the motor is driven and the fan rotates, the purge gas is drawn into the vicinity of the second suction hole 21.

[0023] Valve 21B is located between the second suction hole 21 and the second storage tank 41. Valve 21B includes a connection port connected to the second suction hole 21 and a connection port connected to the inlet portion of the second storage tank 41. Valve 21B may be constituted by a valve such as electromagnetic drive, piezo drive or motor drive.

[0024] By the control unit 64 controlling valve 21B, the connection state between the second suction hole 21 and the second storage tank 41 is switched. For example, the control unit 64 switches the connection state between them to a state where the second suction hole 21 and the second storage tank 41 are connected, or a state where the second suction hole 21 and the second storage tank 41 are not connected.

[0025] When the second suction hole 21 sucks the purge gas, the control unit 64 controls valve 21B to bring it into a state where the second suction hole 21 and the second storage tank 41 are connected. Further, when the purge gas is stored in the second storage tank 42, the control unit 64 controls valve 21B to bring it into a state where the second suction hole 21 and the second storage tank 41 are not connected. Since the second storage tank 41 is not connected to the second suction hole 21, the probability of the purge gas in the second storage tank 41 coming into contact with the outside air can be reduced.

[0026] As shown in FIG. 1, a part of the discharge path 22 may be exposed to the outside of the toilet bowl 2A. The discharge path 22 discharges the exhaust gas from the chamber 30 to the outside. This exhaust gas may include the sample gas and the purge gas after the detection process. Further, the discharge path 22 can discharge the residual gas in the first storage tank 40 to the outside through the flow path 23-1, the valve 25, the flow paths 27-1, 27-3 and the third supply unit 52. Further, the discharge path 22 can discharge the residual gas in the second storage tank 41 to the outside through the flow path 24-1, the valve 26, the flow paths 27-2, 27-3 and the third supply unit 52. The discharge path 22 may be constituted by a tubular member such as a resin tube or a metal or glass pipe.

[0027] One end of the flow path 23-1 is connected to the outlet of the first storage tank 40. The other end of the flow path 23-1 is connected to the valve 25. One end of the flow path 23-2 is connected to the valve 25. The other end of the flow path 23-2 is connected to the chamber 30 via the first supply unit 50. The flow path 23 may be composed of a tubular member such as a resin tube or a metal or glass pipe.

[0028] One end of the flow path 24-1 is connected to the outlet of the second storage tank 41. The other end of the flow path 24-1 is connected to the valve 26. One end of the flow path 24-2 is connected to the valve 26. The other end of the flow path 24-2 is connected to the chamber 30 via the second supply unit 51. The flow path 24 may be composed of a tubular member such as a resin tube or a metal or glass pipe.

[0029] The valve 25 is located between the flow path 23-1, the flow path 23-2, and the flow path 27-1. The valve 25 includes a connection port connected to the flow path 23-1, a connection port connected to the flow path 23-2, and a connection port connected to the flow path 27-1. The valve 25 may be composed of a valve such as an electromagnetic drive, a piezo drive, or a motor drive.

[0030] By controlling the valve 25 by the control unit 64, the connection state between the flow path 23-1, the flow path 23-2, and the flow path 27-1 is switched. For example, the control unit 64 switches the connection state between them to a state where the flow path 23-1 and the flow path 23-2 are connected, or a state where the flow path 23-1 and the flow path 27-1 are connected.

[0031] The valve 26 is located between the flow path 24-1, the flow path 24-2, the flow path 27-2, and the flow path 28. The valve 26 includes a connection port connected to the flow path 24-1, a connection port connected to the flow path 24-2, a connection port connected to the flow path 27-2, and a connection port connected to the flow path 28. The valve 26 may be composed of a valve such as an electromagnetic drive, a piezo drive, or a motor drive.

[0032] By controlling the valve 26 by the control unit 64, the connection state among the flow path 24-1, the flow path 24-2, the flow path 27-2, and the flow path 28 is switched. For example, the control unit 64 switches the connection state among them to a state where the flow path 24-1 and the flow path 24-2 are connected, a state where the flow path 24-1 and the flow path 27-2 are connected, or a state where the flow path 24-1 and the flow path 28 are connected.

[0033] One end of the flow path 27-1 is connected to the valve 25. The other end of the flow path 27-1 is connected to one end of the flow path 27-3. One end of the flow path 27-2 is connected to the valve 26. The other end of the flow path 27-2 is connected to one end of the flow path 27-3. One end of the flow path 27-3 is connected to the other end of the flow path 27-1 and the other end of the flow path 27-2. The other end of the flow path 27-3 is connected to the discharge path 22 via the third supply unit 52. The flow path 27 may be composed of a tubular member such as a resin tube or a metal or glass pipe.

[0034] One end of the flow path 28 is connected to the valve 20B. The other end of the flow path 28 is connected to the valve 26. The flow path 28 may be composed of a tubular member such as a resin tube or a metal or glass pipe. When the control unit 64 controls the valve 20B and the valve 26 and the flow path 24-1, the flow path 28, and the first storage tank 40 are connected, the purge gas in the second storage tank 41 is supplied to the first storage tank 40. At this time, the sample gas in the first storage tank 40 is pushed out into the flow path 23-1.

[0035] Chamber 30 has, inside thereof, a sensor unit 31 that is different from the above-described sensor unit 63. Chamber 30 may have a plurality of sensor units 31. Sensor units 31-1, 31-2, and 31-3 are part of the plurality of sensor units 31. Chamber 30 may be divided into a plurality. Each sensor unit 31 may be arranged in each of the divided chambers 30. The divided chambers 30 may be connected to each other. Chamber 30 is connected to flow path 23-2 via first supply unit 50. Sample gas is supplied to chamber 30 from flow path 23-2. Also, chamber 30 is connected to flow path 24-2 via second supply unit 51. Purge gas is supplied to chamber 30 from flow path 24-2. Further, chamber 30 is connected to discharge path 22. The exhaust from chamber 30 containing the sample gas and the purge gas after the detection process is discharged through discharge path 22.

[0036] The sensor unit 31 is disposed within the chamber 30. The sensor unit 31 outputs a detection value corresponding to the detection result of the gas to be detected which is the object of detection. In the present embodiment, the sensor unit 31 outputs a voltage corresponding to the concentration of the gas to be detected to the control unit 64. In the present embodiment, the sensor unit 31 outputs a plurality of detection values for each of a plurality of gases to be detected. Here, the gas supplied to the chamber 30 includes the gas to be detected and the gas other than the object of detection. For example, the sample gas includes methane, hydrogen, carbon dioxide, methyl mercaptan, hydrogen sulfide, acetic acid, trimethylamine, ammonia, water, and the like. Further, the sample gas includes a gas based on phenols including phenol and cresol, and a gas based on indoles including indole and skatole. Here, phenol and cresol are decomposition substances of tyrosine which is a raw material of noradrenaline, and substances which have been confirmed to be contained in fecal odor. Further, indole and skatole are decomposition substances of tryptophan which is a raw material of serotonin, and substances which have been confirmed to be contained in fecal odor. Hereinafter, the gas based on phenols and the gas based on indoles are simply described as phenols and indoles, respectively. In the present embodiment, the gas to be detected includes at least phenols and indoles. Further, when the gas generated from feces is targeted, since ammonia is a component contained in urine and water is a component contained in urine and washing water, at least ammonia and water are gases other than the object of detection.

[0037] As shown in FIG. 4, the sensor unit 31 includes a sensor element 31S and a resistance element 31R. The sensor element 31S and the resistance element 31R are connected in series between the power supply terminal P1 and the ground terminal P2. A constant voltage value V C is applied between the power supply terminal P1 and the ground terminal P2. The same current value I S flows through each of the sensor element 31S and the resistance element 31R. The current value I S can be determined according to the resistance value R S of the sensor element 31S and the resistance value R L of the resistance element 31R. The voltage output by the sensor unit 31 is the voltage value V applied to the sensor element 31SS may be, or the voltage value V applied to the resistance element 31R RL may be.

[0038] The power supply terminal P1 shown in FIG. 4 is connected to a power supply such as a battery included in the stress measurement system 1. The ground terminal P2 is connected to the ground of the stress measurement system 1.

[0039] One end of the sensor element 31S shown in FIG. 4 is connected to the power supply terminal P1. The other end of the sensor element 31S is connected to one end of the resistance element 31R. The sensor element 31S is a semiconductor sensor. However, the sensor element 31S is not limited to a semiconductor sensor. For example, the sensor element 31S may be a catalytic combustion type sensor or a solid electrolyte sensor or the like.

[0040] The sensor element 31S includes a gas sensing part. The gas sensing part includes a metal oxide semiconductor material according to the type of the sensor part 31. As an example of the metal oxide semiconductor material, one or more selected from tin oxide (such as SnO2), indium oxide (such as In2O3), zinc oxide (such as ZnO), tungsten oxide (such as WO3), iron oxide (such as Fe2O3), etc. are included. By appropriately adding impurities to the metal oxide semiconductor material of the gas sensing part, the gas detected by the sensor element 31S can be appropriately selected. The sensor element 31S may further include a heater for heating the gas sensing part.

[0041] When the sensor element 31S is exposed to the purge gas, oxygen contained in the purge gas can be adsorbed on the surface of the gas sensing part of the sensor element 31S. Oxygen adsorbed on the surface of the gas sensing part can capture free electrons on the surface of the gas sensing part. When free electrons are captured by oxygen adsorbed on the surface of the gas sensing part, the resistance value R S of the sensor element 31S increases, and the voltage value V S applied to the sensor element 31S may increase. That is, when the purge gas is supplied to the sensor part 31, the voltage value V S applied to the sensor element 31S may increase. Here, the voltage value V S and the voltage value V RLThe combined value of these is constant. Therefore, when purge gas is supplied to the sensor unit 31, the voltage value V RL can decrease.

[0042] When the sensor element 31S is exposed to the sample gas, the detected gas contained in the sample gas and the oxygen adsorbed on the surface of the gas-sensitive part of the sensor element 31S can be replaced, and a reduction reaction can occur. When the reduction reaction occurs, the oxygen adsorbed on the surface of the gas-sensitive part can be removed. When the oxygen adsorbed on the surface of the gas-sensitive part is removed, the resistance value R S of the sensor element 31S decreases, and the voltage value V S applied to the sensor element 31S can decrease. That is, when the sample gas is supplied to the sensor unit 31, the voltage value V S applied to the sensor element 31S can decrease according to the concentration of the detected gas contained in the sample gas. Here, the combined value of the voltage value V S and the voltage value V RL is constant. Therefore, when the sample gas is supplied to the sensor unit 31, the voltage value V RL can increase according to the concentration of the detected gas contained in the sample gas.

[0043] The resistance element 31R is a variable resistance element. The resistance value R L of the resistance element 31R can be changed by a control signal from the control unit 64. One end of the resistance element 31R is connected to the other end of the sensor element 31S. The other end of the resistance element 31R is connected to the ground terminal P2.

[0044] By adjusting the resistance value R L of the resistance element 31R, the voltage value V S applied to the sensor element 31S can be adjusted. For example, when the resistance value R L is made equal to the resistance value R S of the sensor element 31S, the fluctuation range of the voltage value V S applied to the sensor element 31S can approach the maximum value.

[0045] The first storage tank 40 can store the sample gas. Inside the first storage tank 40, an adsorbent 40a, an adsorbent 40b, and an adsorbent 40c may be arranged. Also, in the first storage tank 40, the sample gas may be concentrated. In the present disclosure, "concentration of the sample gas" means increasing the concentration of the gas to be detected contained in the sample gas. Each of the adsorbent 40a, the adsorbent 40b, and the adsorbent 40c may each contain any material according to the application. Each of the adsorbent 40a, the adsorbent 40b, and the adsorbent 40c may contain, for example, at least one of activated carbon, silica gel, zeolite, MOF (Metal Organic Frameworks) material, molecular imprint material, and molecular sieve. The adsorbent 40a, the adsorbent 40b, and the adsorbent 40c may be of multiple types or may contain a porous material.

[0046] The adsorbent 40a may include at least one of, for example, silica gel and zeolite. Further, the adsorbent 40b may include at least one of, for example, activated carbon, MOF material, molecular imprint material, and molecular sieve. The adsorbent 40c may include at least one of, for example, activated carbon, MOF material, molecular imprint material, and molecular sieve. The configurations of the adsorbent 40a, the adsorbent 40b, and the adsorbent 40c are not limited to the above, and may be appropriately changed depending on the polarity of the gas molecules to be adsorbed. In the present embodiment, one of the adsorbent 40b and the adsorbent 40c adsorbs phenols. The other of the adsorbent 40b and the adsorbent 40c adsorbs indoles. Generally, the boiling points of phenols and indoles are often higher than normal temperature (15 to 25 °C), and they may be contained in the sample gas only on the ppb order. In the present embodiment, in the first storage tank 40, the adsorbent 40b and the adsorbent 40c selectively adsorb phenols and indoles, and when the temperature reaches a predetermined temperature by heating with a heater, the phenols and indoles are desorbed. That is, the first storage tank 40 increases the concentration of the detected gas by heating and desorbing the phenols and indoles, which are the detected gases selectively adsorbed by the adsorbent 40b and the adsorbent 40c. Thus, in the first storage tank 40, the sample gas is concentrated. Further, the adsorbent 40a adsorbs noise gas that is neither phenols nor indoles. That is, the first storage tank 40 performs removal of noise gas. By the concentration and the removal of noise gas performed in the first storage tank 40, the sensor unit 31 can improve the detection accuracy of phenols and indoles. Here, the first storage tank 40 may perform only one of the concentration of the detected gas and the removal of noise gas. Specifically, the concentration of the sample gas described above is achieved, for example, by sequentially performing the following steps (1) to (3). (1) With the first suction hole 20, the first storage tank 40, the flow path 23-1, the flow path 27-1, the flow path 27-3, the third supply unit 52, and the discharge path 22 connected (communicated), the sample gas is adsorbed by the adsorbent 40a or the adsorbent 40b at normal temperature or a temperature higher than that. (2) With both the valve 20B and the valve 25 closed, heat the adsorbent 40a or the adsorbent 40b at a temperature higher than the temperature in the step (1) to desorb the sample gas. (3) With the second storage tank 41, the flow path 24-1, the flow path 28, the first storage tank 40, the flow path 23-1, the flow path 23-2, the first supply unit 50, the chamber 30, and the discharge path 22 connected (communicated), send the concentrated gas generated in the first storage tank 40 in the step (2) into the chamber 30.

[0047] In the first storage tank 40, the adsorbent 40a may be partitioned and arranged by a wall or the like. By partitioning the adsorbent 40a, the gas flow path in the first storage tank 40 can be lengthened. By lengthening the gas flow path in the first storage tank 40, the contact time between the gas and the adsorbent 40a can be lengthened. Similarly, in the first storage tank 40, the adsorbent 40b may be partitioned and arranged by a wall or the like. By partitioning the adsorbent 40b, the contact time between the gas and the adsorbent 40b in the first storage tank 40 can be lengthened. Also, similarly, in the first storage tank 40, the adsorbent 40c may be partitioned and arranged by a wall or the like. By partitioning the adsorbent 40c, the contact time between the gas and the adsorbent 40c in the first storage tank 40 can be lengthened.

[0048] In the first storage tank 40, the adsorbent 40a may be arranged on the side where the first storage tank 40 is connected to the first suction hole 20. In the first storage tank 40, the adsorbent 40c may be arranged on the side where the first storage tank 40 is connected to the flow path 23-1. Also, in the first storage tank 40, the adsorbent 40b may be arranged between the adsorbent 40a and the adsorbent 40c.

[0049] The first storage tank 40 may be composed of a rectangular parallelepiped shape, a cylindrical shape, a bag shape, or a tank or the like having a shape that fills the gaps between various parts housed inside the housing 10. The first storage tank 40 may be provided with a heater for heating at least one of the inner wall of the first storage tank 40, the adsorbent 40a, the adsorbent 40b, and the adsorbent 40c.

[0050] The entire first storage tank 40 may be partitioned by a wall or the like. By partitioning the entire first storage tank 40, in the first storage tank 40, the cross-sectional area of the gas flow path can be made smaller than the volume of the gas flow path. The cross-sectional area of the gas flow path becomes smaller than the volume of the gas flow path. As a result, when the sample gas is pushed out from the first storage tank 40 into the chamber 30, the contact area between the gas flowing into the first storage tank 40 from the valve 20B and the sample gas stored in the first storage tank 40 can be made smaller. The contact area between the gas flowing into the first storage tank 40 from the valve 20B and the sample gas stored in the first storage tank 40 becomes smaller. Thereby, it can be reduced that the gas flowing into the first storage tank 40 from the valve 20B is mixed with the sample gas in the first storage tank 40.

[0051] The second storage tank 41 can store purge gas. Inside the second storage tank 41, an adsorbent 41a, an adsorbent 41b, and an adsorbent 41c may be arranged. Each of the adsorbent 41a, the adsorbent 41b, and the adsorbent 41c may contain any material according to the application. Each of the adsorbent 41a, the adsorbent 41b, and the adsorbent 41c may contain at least one of, for example, activated carbon, silica gel, zeolite, MOF material, molecular imprint material, and molecular sieve. The adsorbent 41a, the adsorbent 41b, and the adsorbent 41c may be of multiple types or may contain a porous material.

[0052] The adsorbent 41a may contain at least one of, for example, silica gel and zeolite. Further, the adsorbent 41b may contain at least one of, for example, activated carbon, MOF material, molecular imprint material, and molecular sieve. The adsorbent 41c may contain at least one of, for example, activated carbon, MOF material, molecular imprint material, and molecular sieve. The configurations of the adsorbent 41a, the adsorbent 41b, and the adsorbent 41c are not limited to the above, and may be appropriately changed according to the polarity of the gas molecules to be adsorbed. For example, one of the adsorbent 41b and the adsorbent 41c may adsorb phenols. The other of the adsorbent 41b and the adsorbent 41c may adsorb indoles. The adsorbent 41a may adsorb noise gas that is neither phenols nor indoles.

[0053] In the second storage tank 41, the adsorbent 41a may be partitioned and arranged by a wall or the like. By partitioning the adsorbent 41a, the gas flow path in the second storage tank 41 can be lengthened. By lengthening the gas flow path in the second storage tank 41, the time for the gas to contact the adsorbent 41a can be lengthened. Similarly, in the second storage tank 41, the adsorbent 41b may be partitioned and arranged by a wall or the like. By partitioning the adsorbent 41b, the time for the gas to contact the adsorbent 41b in the second storage tank 41 can be lengthened. Also, similarly, in the second storage tank 41, the adsorbent 41c may be partitioned and arranged by a wall or the like. By partitioning the adsorbent 41c, the time for the gas to contact the adsorbent 41c in the second storage tank 41 can be lengthened.

[0054] In the second storage tank 41, the adsorbent 41a may be arranged on the side where the second storage tank 41 is connected to the second suction hole 21. In the second storage tank 41, the adsorbent 41c may be arranged on the side where the second storage tank 41 is connected to the flow path 24-1. Also, in the second storage tank 41, the adsorbent 41b may be arranged between the adsorbent 41a and the adsorbent 41c.

[0055] The second storage tank 41 may be composed of a rectangular parallelepiped shape, a cylindrical shape, a bag shape, or a tank or the like having a shape that fills the gaps between various parts housed inside the housing 10. The second storage tank 41 may be provided with a heater for heating at least one of the inner wall of the second storage tank 41, the adsorbent 41a, the adsorbent 41b, and the adsorbent 41c.

[0056] The entire second storage tank 41 may be partitioned by a wall or the like. By partitioning the entire second storage tank 41, in the second storage tank 41, the cross-sectional area of the gas flow path can be made smaller than the volume of the gas flow path. The cross-sectional area of the gas flow path becomes smaller than the volume of the gas flow path. As a result, when the purge gas is pushed out from the second storage tank 41 into the chamber 30, the contact area between the gas flowing into the second storage tank 41 from the valve 21B and the purge gas stored in the second storage tank 41 can be made smaller. The contact area between the gas flowing into the second storage tank 41 from the valve 21B and the purge gas stored in the second storage tank 41 becomes smaller. Thereby, the mixing of the gas flowing into the second storage tank 41 from the valve 21B with the purge gas in the second storage tank 41 can be reduced. With such a configuration, for example, when the gas near the second suction hole 21 is contaminated, the mixing of the contaminated gas with the purge gas in the second storage tank 41 can be reduced.

[0057] The first supply unit 50 is attached to the flow path 23-2. When the flow path 23-1 and the flow path 23-2 are connected, the first supply unit 50 can supply the sample gas stored in the first storage tank 40 to the chamber 30. The first supply unit 50 is driven or stopped according to the control of the control unit 64. The arrow on the first supply unit 50 in FIG. 2 indicates the direction in which the first supply unit 50 sends the sample gas. The first supply unit 50 may be composed of a piezo pump, a motor pump, or the like.

[0058] The second supply unit 51 is attached to the flow path 24-2. When the flow path 24-1 and the flow path 24-2 are connected, the second supply unit 51 can supply the purge gas stored in the second storage tank 41 to the chamber 30. The second supply unit 51 is driven or stopped according to the control of the control unit 64. The arrow on the second supply unit 51 in FIG. 2 indicates the direction in which the second supply unit 51 sends the purge gas. The second supply unit 51 may be composed of a piezo pump, a motor pump, or the like.

[0059] The third supply unit 52 is attached to the flow path 27-3. When the flow path 23-1 and the flow path 27-1 are connected, the third supply unit 52 can supply residual gas or the like in the first storage tank 40 to the discharge path 22. Also, when the flow path 24-1 and the flow path 27-2 are connected, the third supply unit 52 can supply residual gas or the like in the second storage tank 41 to the discharge path 22. The third supply unit 52 is driven or stopped according to the control of the control unit 64. The arrow on the third supply unit 52 in Fig. 2 indicates the direction in which the third supply unit 52 sends residual gas or the like. The third supply unit 52 may be composed of a piezo pump, a motor pump, or the like.

[0060] In addition, the third supply unit 52 also has a function of drawing in the sample gas and the purge gas into the first storage tank 40 and the second storage tank 41, respectively. When the first suction hole 20 and the first storage tank 40 are connected, and the flow path 23-1 and the flow path 27-1 are connected, the third supply unit 52 can supply the sample gas from the first suction hole 20 to the first storage tank 40. Also, when the second suction hole 21 and the second storage tank 41 are connected, and the flow path 24-1 and the flow path 27-2 are connected, the third supply unit 52 can supply the purge gas from the second suction hole 21 to the second storage tank 41.

[0061] As described above, the circuit board 60 includes a storage unit 61, a communication unit 62, a control unit 64, etc. (see Fig. 3). The storage unit 61 is composed of, for example, a semiconductor memory or a magnetic memory. The storage unit 61 stores various information and a program for operating the stress measurement system 1. The storage unit 61 may function as a work memory.

[0062] The storage unit 61 stores, for example, an algorithm for multiple regression analysis. The storage unit 61 stores, for example, a model formula in multiple regression analysis (for example, the model formula (2) described later). The storage unit 61 stores information regarding the standard gas described later. The storage unit 61 stores information regarding a prediction formula (for example, information on the prediction formula (1) described later) determined or updated in the stress measurement system 1 or an external server.

[0063] The communication unit 62 communicates with the electronic device 3 that shows the degree of stress of the subject measured by the control unit 64 to the subject, for example, by display on the display unit 3A or by voice. The communication unit 62 may be capable of communicating with an external server. The communication method used in the communication between the communication unit 62, the electronic device 3, and the external server may be a short-range wireless communication standard or a wireless communication standard for connecting to a mobile phone network, or may be a wired communication standard. The short-range wireless communication standard may include, for example, WiFi (registered trademark), Bluetooth (registered trademark), infrared, and NFC (Near Field Communication), etc. The wireless communication standard for connecting to a mobile phone network may include, for example, LTE (Long Term Evolution) or a mobile communication system of the fourth generation or higher. Also, the communication method used in the communication between the communication unit 62, the electronic device 3, and the external server may be a communication standard such as LPWA (Low Power Wide Area) or LPWAN (Low Power Wide Area Network).

[0064] The sensor unit 63 may be configured to include at least any one of an image camera, a personal identification switch, an infrared sensor, a pressure sensor, etc. The sensor unit 63 outputs the detection result to the control unit 64.

[0065] For example, when the sensor unit 63 includes an infrared sensor, the sensor unit 63 can detect that the subject has entered the toilet room by detecting the reflected light of the infrared rays irradiated by the infrared sensor from the object. The sensor unit 63 outputs a signal indicating that the subject has entered the toilet room to the control unit 64 as the detection result.

[0066] For example, when the sensor unit 63 includes a pressure sensor, the sensor unit 63 can detect that the subject has sat on the toilet seat 2B by detecting the pressure applied to the toilet seat 2B shown in FIG. 1. The sensor unit 63 outputs a signal indicating that the subject has sat on the toilet seat 2B to the control unit 64 as the detection result.

[0067] For example, when the sensor unit 63 includes a pressure sensor, it can detect that the subject has risen from the toilet seat 2B by detecting a reduction in the pressure applied to the toilet seat 2B shown in FIG. 1. The sensor unit 63 outputs, as a detection result, a signal indicating that the subject has risen from the toilet seat 2B to the control unit 64.

[0068] For example, when the sensor unit 63 includes an image camera, a personal identification switch, etc., it collects data such as face images, seat height, and weight. The sensor unit 63 identifies and detects an individual from the collected data. The sensor unit 63 outputs, as a detection result, a signal indicating the identified individual to the control unit 64.

[0069] For example, when the sensor unit 63 includes a personal identification switch, etc., it identifies (detects) an individual based on the operation of the personal identification switch. In this case, personal information may be registered (stored) in the storage unit 61 in advance. The sensor unit 63 outputs, as a detection result, a signal indicating the identified individual to the control unit 64.

[0070] The control unit 64 includes one or more processors. The processor may include at least either a general-purpose processor that reads a specific program and executes a specific function, or a dedicated processor specialized for a specific process. The dedicated processor may include an application-specific integrated circuit (ASIC). The processor may include a programmable logic device (PLD). The PLD may include a field-programmable gate array (FPGA). The control unit 64 may include at least either a system-on-a-chip (SoC) in which one or more processors cooperate, or a system-in-a-package (SiP). The control unit 64 may execute calculations (for example, processes for obtaining the type and concentration of gas, stress measurement processes, etc.) described later according to a program.

[0071] <Detection Process of Gas Type and Concentration> The control unit 64 stores the purge gas in the second storage tank 41, for example, by connecting the flow path 24-1 and the flow path 24-2 and driving the second supply unit 51. Then, the control unit 64 supplies the purge gas stored in the second storage tank 41 to the chamber 30. Here, when the purge gas near the second suction hole 21 is contaminated, the control unit 64 may close the valve 21B so that the purge gas is not introduced into the second storage tank 41. When the second storage tank 41 is made of, for example, resin or bellows structure and the internal volume can be changed, the control unit 64 may execute a process to prevent the above-mentioned introduction of the purge gas.

[0072] The control unit 64 stores the sample gas in the first storage tank 40, for example, by connecting the flow path 23-1 and the flow path 23-2 and driving the first supply unit 50. Then, the control unit 64 supplies the sample gas stored in the first storage tank 40 to the chamber 30. Here, when it is desired to suppress the mixing of the sample gas near the first suction hole 20 and the sample gas already stored in the first storage tank 40, the control unit 64 may close the valve 20B so that the sample gas is not introduced into the first storage tank 40. At this time, the control unit 64 controls the valve 20B and the valve 26 to connect the first storage tank 40 to the second storage tank 41 via the flow path 28 and the flow path 24-1 so that the purge gas stored in the second storage tank 41 is supplied to the first storage tank 40. When the first storage tank 40 is made of, for example, resin or bellows structure and the internal volume can be changed, the control unit 64 may execute a process to prevent the above-mentioned introduction of the sample gas.

[0073] The control unit 64 controls the second supply unit 51 and the first supply unit 50 to alternately supply the purge gas and the sample gas to the chamber 30. The control unit 64 acquires the voltage waveform output by the sensor unit 31 of the chamber 30. The control unit 64 acquires the voltage waveform shown in FIG. 5, for example, by acquiring the voltage value V RL applied to the resistance element 31R.

[0074] FIG. 5 is a diagram showing an example of the voltage waveform of the sensor unit 31. The horizontal axis of FIG. 5 indicates time. The vertical axis of FIG. 5 indicates voltage. The voltage value indicated by the voltage waveform V1 is the voltage value V applied to the resistance element 31R of the sensor unit 31-1 RL is. The voltage value indicated by the voltage waveform V2 is the voltage value V applied to the resistance element 31R of the sensor unit 31-2 RL is. The voltage value indicated by the voltage waveform V3 is the voltage value V applied to the resistance element 31R of the sensor unit 31-3 RL is.

[0075] The first period T1 is a period during which the sample gas stored in the first storage tank 40 is supplied to the chamber 30. When the sample gas is supplied to the sensor unit 31, the voltage value V of the resistance element 31R may increase according to the concentration of the gas to be detected contained in the sample gas RL can. Therefore, in the first period T1, the voltage values indicated by the voltage waveforms V1 to V3 increase

[0076] The second period T2 is a period during which the purge gas stored in the second storage tank 41 is supplied to the chamber 30. When the purge gas is supplied to the sensor unit 31, the voltage value V of the resistance element 31R RL can decrease. Therefore, in the second period T2, the voltage values indicated by the voltage waveforms V1 to V3 decrease

[0077] The control unit 64 detects the types and concentrations of gases contained in the sample gas based on a multiple regression analysis using the characteristics of the voltage waveform output by the sensor unit 31 as explanatory variables. As an example of the characteristics of the voltage waveform that can be explanatory variables, there are the slope, average value, median value of the voltage waveform in a predetermined interval, the differences between these numerical values, and the ratios of these numerical values between different sensor units 31. In the example shown in FIG. 5, the intervals t1 to t6 can be the predetermined intervals. The widths of the intervals t1 to t6 are the same. However, the widths of the intervals t1 to t6 may be different. Also, the slope of the voltage waveform in interval t1 can be one of the explanatory variables. The slopes of the voltage waveforms V1 to V3 in interval t1 are respectively described as "explanatory variable x11", "explanatory variable x12", and "explanatory variable x13". Also, the slope of the voltage waveform in interval t2 can be one of the explanatory variables. The slopes of the voltage waveforms V1 to V3 in interval t2 are respectively described as "explanatory variable x21", "explanatory variable x22", and "explanatory variable x23". Also, the average value of the voltage waveform in interval t3 can be one of the explanatory variables. The average values of the voltage waveforms V1 to V3 in interval t3 are respectively described as "explanatory variable x31", "explanatory variable x32", and "explanatory variable x33". Also, the slope of the voltage waveform in interval t4 can be one of the explanatory variables. The slopes of the voltage waveforms V1 to V3 in interval t4 are respectively described as "explanatory variable x41", "explanatory variable x42", and "explanatory variable x43". Also, the slope of the voltage waveform in interval t5 can be one of the explanatory variables. The slopes of the voltage waveforms V1 to V3 in interval t5 are respectively described as "explanatory variable x51", "explanatory variable x52", and "explanatory variable x53". Also, the average value of the voltage waveform in interval t6 can be one of the explanatory variables. The average values of the voltage waveforms V1 to V3 in interval t6 are respectively described as "explanatory variable x61", "explanatory variable x62", and "explanatory variable x63".

[0078] The control unit 64 detects the types and concentrations of the gases contained in the sample gas based on the prediction formula determined by multiple regression analysis and the explanatory variables used in the prediction formula among the explanatory variables. For example, the control unit 64 detects the types and concentrations of the gases contained in the sample gas based on the following prediction formula (1). The prediction formula (1) is an example of a prediction formula for predicting the concentration of a predetermined gas. The prediction formula (1) is determined by multiple regression analysis using a mixed gas with a known gas composition. The process of determining the prediction formula (1) will be described later.

Number

[0079] The control unit 64 may acquire information regarding the prediction formula from the outside via the storage unit 61 or the communication unit 62. The information regarding the prediction formula may include information on the prediction formula, information on the explanatory variables used in the prediction formula, information on a predetermined interval, and information on operations for acquiring the explanatory variables. The predetermined interval is an interval used when dividing the voltage waveform into a plurality of sections. The predetermined interval corresponds to the widths of the respective sections t1 to t6 shown in FIG. 5. For example, in the case of the prediction formula (1), the information regarding the prediction formula may include information on the prediction formula (1), information on the explanatory variables x11, x22, x33 used in the prediction formula (1), information on the predetermined interval, and information on operations for acquiring the explanatory variables x11, x22, x33. For example, when the control unit 64 acquires the information regarding the prediction formula, the control unit 64 divides the voltage waveform shown in FIG. 5 into a plurality of sections, i.e., sections t1 to t6, by dividing it at the predetermined interval along the time axis. Further, the control unit 64 acquires the explanatory variable x11 by calculating the slope of the voltage waveform V1 in the section t1 shown in FIG. 5 based on the information on the operations for acquiring the explanatory variables. Further, the control unit 64 acquires the explanatory variable x22 by calculating the average value of the voltage waveform V2 in the section t2 shown in FIG. 5. Further, the control unit 64 acquires the explanatory variable x33 by calculating the average value of the voltage waveform V3 in the section t3 shown in FIG. 5. The control unit 64 detects the concentration y1 of a predetermined gas by substituting the explanatory variables x11, x22, x33 into the above prediction formula (1).

[0080] Here, regarding the width of the interval corresponding to the explanatory variable, in the example shown in FIG. 5, the widths of intervals t1 to t6 do not have to be the same. For example, the widths of the intervals corresponding to the explanatory variable may be different. Also, in the intervals corresponding to the explanatory variable, some intervals may overlap. The intervals corresponding to the explanatory variable may include further subdivided intervals for obtaining a certain explanatory variable. The setting of the appropriate intervals corresponding to the explanatory variable may be appropriately selected in advance according to the data of the voltage waveform output by the sensor unit 31, the time interval for obtaining the voltage waveform, the magnitude or frequency of the noise included in the voltage waveform. Not all the data of the voltage waveform output by the sensor unit 31 has to be used for detecting the type and concentration of the gas. For example, among the voltage waveforms output by the sensor unit 31, only the necessary data, for example, by thinning out unnecessary parts, may be used for detecting the type and concentration of the gas.

[0081] The control unit 64 may use different prediction formulas according to the type of gas. By using different prediction formulas according to the type of gas, the control unit 64 can detect the concentration for each type of gas included in the sample gas. In other words, the control unit 64 can detect the type and concentration of the gas included in the sample gas.

[0082] The control unit 64 may transmit the detected type and concentration of the gas to the electronic device 3 via the communication unit 62. Also, after the detection process is completed, the control unit 64 may connect the flow path 23-1 and the flow path 27-1 and drive the third supply unit 52 to discharge the residual gas in the first storage tank 40 from the discharge path 22. Also, after the detection process is completed, the control unit 64 may connect the flow path 24-1 and the flow path 27-2 and drive the third supply unit 52 to discharge the residual gas in the second storage tank 41 from the discharge path 22.

[0083] <Determination process of prediction formula> The following determination process of the prediction formula may be executed before the shipment of the stress measurement system 1 or during maintenance, etc.

[0084] When the control unit 64 receives a control signal for instructing purge gas suction based on a pre - incorporated program or from the outside via the communication unit 62, it causes the purge gas to be sucked into the second suction hole 21 in the same manner as described above. The control signal for instructing purge gas suction can be transmitted to the stress measurement system 1 when determining a prediction formula before the shipment of the stress measurement system 1 or the like. By causing the purge gas to be sucked into the second suction hole 21, the control unit 64 stores the purge gas in the second storage tank 41.

[0085] When the control unit 64 receives a control signal for instructing sample gas suction based on a pre - incorporated program or from the outside via the communication unit 62, it causes the sample gas to be sucked into the first suction hole 20 in the same manner as described above. The control signal for instructing sample gas suction can be transmitted to the stress measurement system 1 when determining a prediction formula before the shipment of the stress measurement system 1 or the like. By causing the sample gas to be sucked into the first suction hole 20, the control unit 64 stores the sample gas in the first storage tank 40. Here, in the process of determining the prediction formula, a mixed gas with a known gas composition is used as the sample gas. That is, a mixed gas with a known gas composition is stored in the first storage tank 40. Hereinafter, a mixed gas with a known gas composition is also referred to as a "standard gas".

[0086] The control unit 64 acquires a model formula in multiple regression analysis from the storage unit 61 or from the outside via the communication unit 62. The control unit 64 acquires, for example, the following model formula (2).

Equation

[0087] The control unit 64 acquires information about the standard gas from the outside via the storage unit 61 or the communication unit 62. The information about the standard gas includes information on the type and concentration of the gas contained in the standard gas, and information on the acquisition of the explanatory variable, etc. For example, in the case of the model formula (2), the information on the type and concentration of the gas is the information on the type of gas n and the concentration yn. For example, in the case of the model formula (2), the information on the acquisition of the explanatory variable may include the information on interval i and the information on the calculation for acquiring the explanatory variable ij from interval i of the sensor unit 31j.

[0088] The control unit 64 acquires the voltage waveform output by the sensor unit 31 of the chamber 30 by alternately supplying the purge gas and the sample gas to the chamber 30 in the same manner as described above. The control unit 64 executes machine learning with teacher data on the voltage waveform of the sensor unit 31 to acquire effective explanatory variables and regression coefficients in the model formula (2). The control unit 64 determines the prediction formula for gas n by acquiring the effective explanatory variables and regression coefficients.

[0089] For example, in the case of the concentration y1 (n = 1) of a predetermined gas, the control unit 64 acquires the explanatory variables x11, x22, and x33 as effective explanatory variables. The control unit 64 acquires the coefficient A as the coefficient E111 of the explanatory variable x11. The control unit 64 acquires the coefficient B as the coefficient E221 of the explanatory variable x11. The control unit 64 acquires the coefficient C as the coefficient E331 of the explanatory variable x33. The control unit 64 acquires the constant D as the error F. By acquiring the effective explanatory variables x11, 22, x33, the coefficients A, B, C, and the constant D, the control unit 64 determines the above prediction formula (1) for the concentration y1 of the predetermined gas. The control unit 64 may store the effective explanatory variables x11, x22, x33, the coefficients A, B, C, and the constant D in the storage unit 61.

[0090] The control unit 64 can determine different prediction formulas according to the type of gas. Here, the control unit 64 does not have to learn all of the acquired voltage waveform data of the sensor unit 31. Also, the setting of the interval corresponding to the appropriate explanatory variable may be appropriately selected in advance according to the voltage waveform data output by the sensor unit 31, the time interval for acquiring the voltage waveform, the magnitude or frequency of the noise included in the voltage waveform. Alternatively, more effective explanatory variables may be extracted by multiple regression analysis including all conceivable explanatory variables.

[0091] <Stress measurement process> The brain and the gut communicate with each other (via neurotransmitters or hormones in the brain) and interact with each other. For example, it is known that symptoms such as irritable bowel syndrome occur due to stress. Also, some of the substances generated from proteins and lipids in the ingested food in the gut are transported to the brain and are known to be the raw materials for neurotransmitters in the brain. The raw material for the neurotransmitter norepinephrine in the brain is tyrosine. Also, the raw material for the neurotransmitter serotonin in the brain is tryptophan. For example, when tyrosine in the gut is transported from the gut to the brain via derivatives and the amount of tyrosine in the gut decreases, the amount of norepinephrine in the brain increases. When the amount of tyrosine in the gut decreases, the amount of phenols in the gut, which are its decomposition products, also decreases. Also, when tryptophan in the gut is transported from the gut to the brain via derivatives and the amount of tryptophan in the gut decreases, the amount of serotonin in the brain increases. When the amount of tryptophan in the gut decreases, the amount of indoles in the gut, which are its decomposition products, also decreases.

[0092] Here, stress disrupts the balance of the active states of the sympathetic and parasympathetic nerves. That is, by knowing the active states of the sympathetic and parasympathetic nerves, it is possible to measure the degree of stress. For example, when the degree of stress of the subject increases, the sympathetic nerve is activated and the sympathetic nerve becomes dominant over the parasympathetic nerve. At this time, in the gut, tyrosine, which is the raw material for norepinephrine, decreases, and accordingly, phenols also decrease. Also, when the degree of stress of the subject decreases, the parasympathetic nerve is activated, tryptophan, which is the raw material for serotonin, decreases, and accordingly, indoles also decrease.

[0093] FIG. 6 is a diagram illustrating the relationship between the detected values of the concentrations of phenols and indoles, which are the gases to be detected, and the degree of stress of the subject. The horizontal axis in FIG. 6 is the detected value of the concentration of indoles, that is, the voltage corresponding to the concentration of indoles. Further, the vertical axis in FIG. 6 is the detected value of the concentration of phenols, that is, the voltage corresponding to the concentration of phenols. When the degree of stress of the subject is sufficiently low, the balance between the amount of phenols and the amount of indoles in the intestine is maintained, and the detected value of the concentration of indoles and the detected value of the concentration of phenols are included in region R1. Region R1 is defined as a certain range centered on the reference value PO0 obtained as the measured value or calculated value of a person in a stress-free state. The reference value PO0 may be replaced with a reference value PO1 that takes into account individual differences for each subject, as will be described later. When the degree of stress of the subject increases, phenols decrease and indoles increase, so the detected value of the concentration of indoles and the detected value of the concentration of phenols are included in region R2. Region R2 is also defined by a range expanded from the reference value PO0 obtained as the measured value or calculated value of a person in a stress-free state. In FIG. 6, region R2 is surrounded by a line connecting the maximum value of the concentration of indoles in region R1 and the minimum value of the concentration of phenols in region R1, a line extended in the direction in which the concentration of phenols decreases from the maximum value of the concentration of indoles in region R1, and a line extended in the direction in which the concentration of indoles increases from the minimum value of the concentration of phenols in region R1. Here, regions R1 and R2 may be defined by a method such as deep learning, for example. As shown by the dotted arrow in FIG. 6, as the degree of stress of the subject increases, the concentration of indoles relatively increases. Therefore, it is possible to measure the degree of stress of the subject from the ratio of the concentrations of phenols and indoles. Here, when the detected value of the concentration of indoles and the detected value of the concentration of phenols are included in a region (region R3) excluding regions R1 and R2, the subject may be in an abnormal state. That is, when the combination of the concentrations of phenols and indoles is in region R3, the subject may, for example, have serotonin excess, serotonin syndrome, mania, schizophrenia, insomnia, or depression.

[0094] The control unit 64 acquires the detected values of the concentrations of phenols and indoles among the types and concentrations of the gas detected based on the above prediction formula (1). Here, in order to extract only the relationship between noradrenaline and serotonin, the control unit 64 may acquire the detected values of the concentrations of tyrosine and tryptophan.

[0095] The control unit 64 obtains a combination of the detected value of the concentration of phenols and the detected value of the concentration of indoles. The control unit 64 determines whether the obtained combination can be included in the region R1 and the region R2. When the detected value of the concentration of phenols and the detected value of the concentration of indoles obtained are included in the region R2, the control unit 64 determines that the higher the relative concentration of phenols in these ratios, the higher the degree of stress of the subject. Further, when the detected value of the concentration of phenols and the detected value of the concentration of indoles obtained are included in the region R1, the control unit 64 determines that the degree of stress of the subject is sufficiently low. The control unit 64 may convert the degree of stress of the subject into a score, which is a numerical value from 0 to 100, for example. The control unit 64 may transmit the measured degree of stress of the subject to the electronic device 3 via the communication unit 62.

[0096] <Individual difference correction process> The following individual difference correction process may be executed when a certain period has elapsed since the start of use of the stress measurement system 1 or during maintenance, etc.

[0097] The reference value PO0 is a general value determined at the time of designing the stress measurement system 1. Therefore, due to individual differences among subjects, particularly the presence ratio of bacteria in the intestine, it may be necessary to adjust the stress measurement of the control unit 64. For example, when the concentration of phenols is relatively high due to individual differences among subjects, there is a possibility that even if the degree of stress of the subject increases, it may be determined that the subject does not feel stress. By performing the correction process for individual differences, appropriate stress measurement can be performed for each subject. Here, the presence ratio of bacteria in the intestine of the subject may be the presence ratio or the ratio of the presence ratio with respect to the number of bacteria of specific intestinal bacteria of the subject. The specific intestinal bacteria may include at least one of Bifidobacterium, Lactobacillus, Corynebacterium, Staphylococcus, Walshia (Clostridium), Bacteroides, Escherichia coli, Enterobacter, Pseudomonas, and Candida. The number of bacteria of specific intestinal bacteria of the subject may be measured by examining the subject's feces by an inspection institution or the like.

[0098] When executing the stress measurement process, the control unit 64 stores the detected value of the concentration of phenols and the detected value of the concentration of indoles in the storage unit 61. The storage unit 61 accumulates the detected value of the concentration of phenols and the detected value of the concentration of indoles together with, for example, date and time information. The control unit 64 obtains a new reference value PO1 based on a plurality of past detected values stored in the storage unit 61, for example, when a certain period has elapsed since the start of use of the stress measurement system 1. For example, the control unit 64 may obtain a new reference value PO1 by statistically processing the past detected values of the concentration of phenols and the concentration of indoles. As the statistical process, the control unit 64 may obtain, for example, an average value or a median value. The original reference value PO0 is replaced with the reference value PO1 considering individual differences for each subject. As shown in FIG. 7, the regions R1 and R2 move according to the change from the original reference value PO0 to the new reference value PO1.

[0099] [Operation Example of Stress Measurement System] [Operation at the Time of Detecting Gas Type and Concentration] FIG. 8 is a flowchart showing an operation example when detecting the type and concentration of gas in the stress measurement system 1. The control unit 64 may start the process shown in FIG. 8 after a predetermined time has elapsed since detecting that the subject has risen from the toilet seat 2B based on the detection result of the sensor unit 63.

[0100] The control unit 64 causes the purge gas to be sucked into the second suction hole 21 (step S10). By causing the purge gas to be sucked into the second suction hole 21, the control unit 64 stores the purge gas in the second storage tank 41 (step S11).

[0101] After a predetermined time has elapsed since detecting that the subject has sat on the toilet seat 2B based on the detection result of the sensor unit 63, the control unit 64 causes the sample gas to be sucked into the first suction hole 20 (step S12). By causing the sample gas to be sucked into the first suction hole 20, the control unit 64 stores the sample gas in the first storage tank 40 (step S13).

[0102] The control unit 64 controls the second supply unit 51 and the first supply unit 50 to alternately supply the purge gas and the sample gas to the chamber 30 (step S14). The control unit 64 acquires the voltage waveform output by the sensor unit 31 in the chamber 30 (step S15).

[0103] The control unit 64 acquires various information from the outside, for example, via the storage unit 61 or the communication unit 62 (step S16). The various information includes information regarding the above prediction formula and the like.

[0104] The control unit 64 divides the voltage waveform output by the sensor unit 31 into a plurality of sections by dividing it at predetermined intervals along the time axis, for example (step S17).

[0105] The control unit 64 sets the resistance element 31R as an adjustment of the resolution of the sensor unit 31 (step S18). Details of the process of step S18 will be described later with reference to FIG. 12.

[0106] The control unit 64 executes the processes of steps S19 and S20 in the same manner as the processes of steps S14 and S15.

[0107] The control unit 64 executes the process of step S21 in the same manner as the process of step S17.

[0108] The control unit 64 acquires the explanatory variables used in the prediction formula based on the information on the operations for acquiring the explanatory variables included in the information on the prediction formula obtained in the process of step S16 (step S22).

[0109] The control unit 64 detects the concentration of a predetermined gas by substituting the explanatory variables acquired in the process of step S22 into the prediction formula (step S23). For example, the control unit 64 detects the concentration y1 of the predetermined gas by substituting the explanatory variables x11, x22, x33 into the above prediction formula (1).

[0110] The control unit 64 executes the process shown in FIG. 8 for each different prediction formula. By executing the process shown in FIG. 8 for each different prediction formula, the type and concentration of the gas can be detected.

[0111] Here, in the process of step S11, the control unit 64 may determine whether the cleanliness of the purge gas is high. Further, when the cleanliness of the purge gas is high, the control unit 64 may store the purge gas in the second storage tank 41. In this case, the control unit 64 may supply the purge gas to the chamber 30 by controlling the second supply unit 51. Further, the control unit 64 may determine whether the cleanliness of the purge gas is high based on the detection result of the sensor unit 31. Also, when the stress measurement system 1 includes a dedicated sensor unit for detecting the cleanliness of the purge gas, the control unit 64 may determine whether the cleanliness of the purge gas is high based on the detection result of the dedicated sensor unit.

[0112] <Operation at the time of determining the prediction formula> Figures 9 and 10 are flowcharts showing the operations during the determination of the prediction formula of the stress measurement system 1 shown in FIG. 1. The processes shown in FIGS. 9 and 10 may be executed before the stress measurement system 1 is shipped as a product. When the control unit 64 receives a control signal instructing purge gas suction from an external source based on a pre - incorporated program or via the communication unit 62, the process shown in FIG. 9 may be started. Here, when determining the prediction formula, a plurality of standard gases with maximized concentrations may be used as the sample gas.

[0113] The control unit 64 executes the processes of steps S30 and 31 in the same manner as the processes of steps S10 and S11 shown in FIG. 8.

[0114] When the control unit 64 receives a control signal instructing sample gas suction from an external source via the communication unit 62, the control unit 64 executes the processes of steps S32 and 33 in the same manner as the processes of steps S12 and S13 shown in FIG. 8.

[0115] The control unit 64 executes the processes of steps S34 and S35 in the same manner as the processes of steps S14 and S15 shown in FIG. 8. By using the standard gas with maximized concentration as described above, the amplitude of the voltage waveform of the sensor unit 31 obtained in the process of step S35 can be maximized.

[0116] The control unit 64 calibrates the sensor unit 31 based on the voltage waveform of the sensor unit 31 obtained in the process of step S35 (step S36). As described above, the amplitude of the voltage waveform of the sensor unit 31 obtained in the process of step S35 can be maximized. Therefore, in the process of step S36, the sensor unit 31 can be calibrated more accurately.

[0117] The control unit 64 executes the processes of steps S37 to S42 in the same manner as the processes of steps S30 to S35. As described above, when determining the prediction formula, a plurality of standard gases are used as the sample gas. Therefore, the control unit 64 repeats the processes of steps S37 to S42 as many times as the number of standard gases used.

[0118] The control unit 64 proceeds to the process shown in FIG. 10. The control unit 64 acquires various types of information from the outside via the storage unit 61 or the communication unit 62 (step S43). The various types of information include a model formula in multiple regression analysis (for example, the above model formula (2)), information regarding the standard gas, and the like.

[0119] The control unit 64 executes the process of step S44 in the same manner as the process of step S17 shown in FIG. 8.

[0120] The control unit 64 acquires effective explanatory variables and regression coefficients in the model formula (for example, the above model formula (2)) by performing machine learning with teacher data on, for example, the voltage waveform (step S45).

[0121] The control unit 64 sets the resistance element 31R as an adjustment of the resolution of the sensor unit 31 (step S46). Details of the process of step S46 will be described later with reference to FIG. 12.

[0122] The control unit 64 executes the processes of steps S47 to S52 in the same manner as the processes of steps S37 to S42 shown in FIG. 9. Similar to the processes of steps S37 to S42 shown in FIG. 9, the control unit 64 repeatedly executes the processes of steps S47 to S52 for the number of standard gases used when determining the prediction formula. The control unit 64 executes the processes of steps S53 and S54 in the same manner as the processes of steps S44 and S45.

[0123] The control unit 64 determines a prediction formula (for example, the above prediction formula (1)) for detecting the concentration of gas n (step S55).

[0124] Here, the control unit 64 does not need to execute the processes of steps S30 to S36 shown in FIG. 9. Further, when the control unit 64 executes the processes of steps S30 to S36 shown in FIG. 9, only a plurality of standard gases with maximized concentration may be used for the processes of steps S30 to S36.

[0125] In addition, the valid explanatory variables and regression coefficients obtained in the process of step S54 may be different from the valid explanatory variables and regression coefficients obtained in the process of step S45. In this case, the control unit 64 may execute the processes of steps S30 to S42 shown in FIG. 9 again, and then execute the processes of steps S44 and S45 again.

[0126] <Operation during stress measurement> FIG. 11 is a flowchart showing an operation example during stress measurement of the stress measurement system 1, that is, an example of a stress measurement method.

[0127] The control unit 64 acquires the detected values of the concentrations of phenols and indoles (step S60). The control unit 64 obtains a combination of the detected values of the concentrations of phenols and indoles (step S61). The control unit 64 measures the degree of stress of the subject based on the obtained combination and the relationship with the regions R1 to R3 (step S62). Here, the data or relational expression for defining the regions R1 to R3 may be stored in the storage unit 61. The control unit 64 transmits the determined degree of stress of the subject to the electronic device 3 via the communication unit 62 (step S63).

[0128] <Operation during individual difference correction> FIG. 12 is a flowchart showing the operation during individual difference correction of the stress measurement system.

[0129] When measuring stress, the control unit 64 stores the detected values of the concentrations of phenols and indoles in the storage unit 61 (step S70). If a certain period has not elapsed since the start of use (No in step S71), the control unit 64 returns to the process of step S70. When a certain period has elapsed since the start of use (Yes in step S71), the control unit 64 acquires a plurality of detected values from the storage unit 61 (step S72). The control unit 64 performs statistical processing on the acquired plurality of detected values (step S73). Based on the result of the statistical processing in step S73, the control unit 64 generates a reference value PO1 considering individual differences for each subject (step S74). The control unit 64 may update the data or relational expression that determines the regions R1 to R3 stored in the storage unit 61 based on the difference between the new reference value PO1 and the original reference value PO0.

[0130] As described above, in the stress measurement system 1 according to the present embodiment, the sensor unit 31 detects a plurality of detected gases based on the substances contained in the specimen of the subject, and outputs a plurality of detected values corresponding to the detection results of the plurality of detected gases. Then, the control unit 64 determines the degree of stress of the subject based on the combination of the plurality of detected values. In the stress measurement system 1 according to the present embodiment, since stress is measured using a plurality of detected gases from the specimen of the subject, the subject does not need to take the trouble of, for example, wearing a measuring device or having blood drawn. Therefore, according to the present embodiment, a stress measurement system 1 capable of measuring the degree of stress of the subject without taking trouble can be provided.

[0131] The drawings for explaining the embodiments according to the present disclosure are schematic. The dimensional ratios on the drawings do not necessarily match the actual ones.

[0132] Embodiments according to the present disclosure have been described based on the drawings and examples. However, it should be noted that those skilled in the art can easily make various modifications or corrections based on the present disclosure. Therefore, it should be noted that these modifications or corrections are included in the scope of the present disclosure. For example, functions included in each component or the like can be rearranged so as not to be logically contradictory, and a plurality of components or the like can be combined into one or divided.

[0133] For example, by separately heating and desorbing the adsorbent 40b and the adsorbent 40c, phenols and indoles can be concentrated as separate gases and separately fed into the chamber 30. That is, the measurement of the phenol-concentrated gas and the indole-concentrated gas can be performed in separate steps, and the phenol concentration can be estimated in the measurement step of the phenol-concentrated gas, and the indole concentration can be estimated in the measurement step of the indole-concentrated gas. This method exhibits the effect of improving the measurement accuracy when the gas sensor unit 31 does not include a gas sensor with a high gas sensor sensitivity to phenols with respect to indoles or a gas sensor with a high gas sensor sensitivity to indoles with respect to phenols.

[0134] For example, in the above embodiment, as shown in FIG. 3, the stress measurement system 1 has been described as one device. However, the stress measurement system of the present disclosure is not limited to one device and may include a plurality of independent devices. The stress measurement system of the present disclosure may have a configuration as shown in FIG. 13, for example.

[0135] The stress measurement system 1B shown in FIG. 13 includes a stress measurement device 4 and a server device 5. The stress measurement device 4 and the server device 5 can communicate via a network 6. A part of the network 6 may be wired or wireless. The configuration of the stress measurement device 4 is the same as that of the stress measurement system 1 shown in FIGS. 2 and 3. The server device 5 includes a storage unit 5A, a communication unit 5B, and a control unit 5C. The control unit 5C can execute the processing of the control unit 64 shown in FIG. 3 described above. For example, the control unit 5C can acquire the voltage waveform output by the sensor unit 31 shown in FIG. 2 via the communication unit 5B and the network 6. Further, the control unit 5C can detect the type and concentration of the gas contained in the sample gas based on the multiple regression analysis using the characteristics of the voltage waveform as explanatory variables.

[0136] For example, after the voltage measurement of the gas by the sensor unit 31, purge gas may be introduced into the first storage tank 40, the second storage tank 42, or the sensor unit 31 until the next suction period. Further, during this period, there may be a period of heating at least one of the heaters of the first storage tank 40 and the second storage tank 41. With such a configuration, the first storage tank 40 and the adsorbents 40a, 40b, 40c, and the second storage tank 41 and the adsorbents 41a, 41b, 41c can be refreshed.

[0137] In the present disclosure, descriptions such as "first" and "second" are identifiers for distinguishing the configurations. The configurations distinguished by the descriptions such as "first" and "second" in the present disclosure can have their numbers in the configuration exchanged. For example, the first suction hole can have the identifiers "first" and "second" exchanged with the second suction hole. The exchange of the identifiers is performed simultaneously. The configurations are still distinguishable after the exchange of the identifiers. The identifiers may be deleted. The configurations with the identifiers deleted are distinguished by reference numerals. Based only on the descriptions of the identifiers such as "first" and "second" in the present disclosure, the order of the configurations should not be interpreted, nor should it be used as a basis for the existence of the identifier with the smaller number.

[0138] Unless otherwise specified, the network used here includes the Internet, ad hoc network, LAN (Local Area Network), WAN (Wide Area Network), MAN (Metropolitan Area Network), cellular network, WWAN (Wireless Wide Area Network), WPAN (Wireless Personal Area Network), PSTN (Public Switched Telephone Network), terrestrial wireless network or other networks or any combination thereof. The components of a wireless network include, for example, access points (e.g., Wi-Fi access points) and femtocells. Further, the wireless communication device can be connected to a wireless network using Wi-Fi, Bluetooth, cellular communication technologies (e.g., CDMA (Code Division Multiple Access), TDMA (Time Division Multiple Access), FDMA (Frequency Division Multiple Access), OFDMA (Orthogonal Frequency Division Multiple Access), SC-FDMA (Single-Carrier Frequency Division Multiple Access) or other wireless technologies and / or technical standards).The network can adopt one or more technologies, and such technologies include, for example, UTMS (Universal Mobile Telecommunications System), LTE (Long Term Evolution), EV-DO (Evolution-Data Optimized or Evolution-Data Only), GSM (Global System for Mobile communications), WiMAX (Worldwide Interoperability for Microwave Access), CDMA-2000 (Code Division Multiple Access-2000) or TD-SCDMA (Time Division Synchronous Code Division Multiple Access).

[0139] Also, a system is disclosed herein as having various modules and / or units that perform specific functions, and these modules and units are shown schematically for the purpose of briefly explaining their functionality and are not necessarily indicative of specific hardware and / or software. It should be noted that in that sense, these modules, units, and other components may be hardware and / or software implemented to substantially perform the specific functions described herein. The various functions of the different components may be in any combination or separation of hardware and / or software and can be used separately or in any combination. Also, input / output or I / O devices or user interfaces, including but not limited to keyboards, displays, touchscreens, pointing devices, etc., can be connected to the system directly or via an intervening I / O controller. Thus, various aspects of the present disclosure can be implemented in many different ways. All of those aspects are included within the scope of the present disclosure.

Explanation of Signs

[0140] 1,1B Stress Measurement System 2 Toilet 2A Toilet Bowl 2B Toilet Seat 3 Electronic Device 3A Display Unit 4 Stress Measurement Device 5 Server Device 5A Storage Unit 5B Communication Unit 5C Control Unit 6 Network 10 Housing 20 First Suction Hole 21 Second Suction Hole 20A,21A Blower 20B,21B Valve 22 Discharge Path 23,23-1,23-2,24,24-1,24-2,27,27-1,27-2,27-3,28 Flow Path 25,26 Valve 30 Chamber 31,31-1,31-2,31-3 Sensor Unit 31S Sensor Element 31R Resistance Element 40 First Reservoir 41 Second Reservoir 40a,40b,40c,41a,41b,41c Adsorbent 50 First Supply Unit 51 Second Supply Unit 52 Third Supply Unit 60 Circuit Board 61 Storage Unit 62 Communication Unit 63 Sensor Unit 64 Control Unit P1 Power Terminal P2 Grounding Terminal

Claims

1. A sensor unit that detects a detected gas caused by the feces of a subject and outputs a detection value according to the detection result of the detected gas; A control unit that determines the degree of stress of the subject based on the detection value, and The detected gas includes a first gas related to the activity state of the sympathetic nerve and a second gas related to the activity state of the parasympathetic nerve, and The control unit determines the degree of stress of the subject based on the detection value of the first gas and the detection value of the second gas. A stress measurement system.

2. The sensor unit detects a plurality of detected gases and outputs a plurality of detection values according to the detection results of the plurality of detected gases, and The control unit determines the degree of stress of the subject based on a combination of the plurality of detection values. The stress measurement system according to claim 1.

3. The sensor unit outputs a detection value according to the concentration of the detected gas. The stress measurement system according to claim 1 or 2.

4. The stress measurement system according to any one of claims 1 to 3, further comprising a display unit that displays the detection value and the degree of stress of the subject.

5. A storage unit that stores the plurality of detection values, and The control unit adjusts the degree of stress to be determined based on the plurality of past detection values stored in the storage unit. The stress measurement system according to claim 2.

6. The control unit determines the degree of stress of the subject using a reference value, and corrects the reference value according to the individual differences of the subject. The stress measurement system according to any one of claims 1 to 5.

7. The control unit determines the degree of stress of the subject using a reference value, and adjusts the reference value based on information related to the intestinal bacteria of the subject. The stress measurement system according to any one of claims 1 to 6.

8. A first suction unit that sucks the detected gas, and A first flow path that connects the first suction unit and the sensor unit. The stress measurement system according to any one of claims 1 to 7.

9. The stress measurement system according to claim 8, further comprising a storage tank that is located between the first suction unit and the sensor unit and can store the detected gas.

10. A second suction unit that sucks a purge gas, and a second flow path that connects the second suction unit and the sensor unit. The stress measurement system according to claim 8.

11. The sensor unit alternately detects the detected gas and the purge gas, and outputs a detection value during a period in which the detected gas and the purge gas are alternately detected. The stress measurement system according to claim 10, wherein the control unit determines the degree of stress of the subject based on detection values during a period in which the detected gas and the purge gas are alternately detected.

12. The stress measurement system according to any one of claims 1 to 11, wherein the sensor unit includes a plurality of sensors.

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