Gas detection system, gas detection device, and gas detection method

Abstract

To provide an improved gas detection system.SOLUTION: A gas detection system comprises: a first sensor unit that outputs a voltage according to the concentration of a specific gas; and a control unit that can control the flow rate of a sample gas and a purge gas supplied to the first sensor unit. The control unit performs control such that, in supplying the sample gas to the first sensor unit, after the lapse of a first time from the start of supply of the sample gas to the first sensor unit, the flow rate of the sample gas becomes smaller than the flow rate at the start of supply of the sample gas.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to Japanese Patent Application No. 2019-083066, filed on April 24, 2019, the entire disclosure of which is incorporated herein by reference. [Technical Field]

[0002] The present disclosure relates to gas detection systems. [Background technology]

[0003] BACKGROUND ART Conventionally, a system for detecting odorous gases generated from feces excreted by a subject is known (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-67538 Summary of the Invention

[0005] A gas detection system according to an embodiment of the present disclosure includes: a first sensor unit that outputs a voltage corresponding to the concentration of a specific gas; a control unit capable of controlling the flow rates of the sample gas and the purge gas supplied to the first sensor unit, When supplying the sample gas to the first sensor unit, the control unit controls the flow rate of the sample gas to be smaller than the flow rate at the start of supplying the sample gas to the first sensor unit after a first time has elapsed since the start of supplying the sample gas to the first sensor unit.

[0006] A gas detection system according to an embodiment of the present disclosure includes: a first sensor unit that outputs a voltage corresponding to the concentration of a specific gas; a control unit capable of controlling the flow rates of the sample gas and the purge gas supplied to the first sensor unit, When supplying the sample gas to the first sensor unit, the control unit stops supplying the sample gas to the first sensor unit after a first time has elapsed since the supply of the sample gas to the first sensor unit began. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is an external view of a gas detection system according to an embodiment of the present disclosure. [Figure 2] 2 is a schematic diagram of the inside of a housing provided in the gas detection system shown in FIG. 1. FIG. [Figure 3] FIG. 2 is a functional block diagram of the gas detection system shown in FIG. [Figure 4] FIG. 3 is an explanatory diagram (part 1) showing the gas flow in the partial configuration shown in FIG. 2. [Figure 5] FIG. 3 is an explanatory diagram (part 2) showing the gas flow in the partial configuration shown in FIG. 2. [Figure 6] 3 is an explanatory diagram (part 3) showing the gas flow in the partial configuration shown in FIG. 2. FIG. [Figure 7] FIG. 4 is an explanatory diagram (part 4) showing the gas flow in the partial configuration shown in FIG. 2. [Figure 8] 5 is an explanatory diagram showing the gas flow in the partial configuration shown in FIG. 2; FIG. [Figure 9] 2 is a flowchart showing the operation of the gas detection system shown in FIG. [Figure 10] 4 is a flowchart showing an operation of the gas detection system shown in FIG. 1 when supplying purge gas. [Figure 11] 4 is a flowchart showing the operation of the gas detection system shown in FIG. 1 when supplying a sample gas. [Figure 12] 3 is a diagram showing another example of the second chamber shown in FIG. 2. FIG. [Figure 13] FIG. 3 is a diagram showing another example 1 of the partial configuration shown in FIG. 2. [Figure 14] FIG. 3 is a diagram showing another example 2 of the partial configuration shown in FIG. [Figure 15] 2. FIG. 4 is a diagram showing another example 3 of the partial configuration shown in FIG. [Figure 16] 2. FIG. 5 is a diagram showing another example 4 of the partial configuration shown in FIG. [Figure 17] 2. FIG. 5 is a diagram showing another example 5 of the partial configuration shown in FIG. [Figure 18] FIG. 10 is a functional block diagram of a gas detection system according to another embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0008] Conventional systems leave room for improvement.

[0009] The present disclosure relates to providing an improved gas detection system.

[0010] According to one embodiment of the present disclosure, an improved gas detection system may be provided.

[0011] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0012] [Gas detection system configuration example] As shown in FIG. 1, the gas detection system 1 is installed in a toilet 2. The toilet 2 may be, but is not limited to, a flush toilet. The gas detection system 1 may be installed in any location on the toilet 2. The toilet 2 includes a toilet bowl 2A and a toilet seat 2B. As an example, the gas detection system 1 may be arranged between the toilet bowl 2A and the toilet seat 2B and outside the toilet 2, as shown in FIG. 1. A portion of the gas detection system 1 may be embedded inside the toilet seat 2B. A subject's feces may be discharged into the toilet bowl 2A of the toilet 2. The gas detection system 1 may acquire, as a sample gas, gas generated from the feces discharged into the toilet bowl 2A. The gas detection system 1 may detect the type and concentration of gas contained in the sample gas. The gas detection system 1 may transmit the detection results to an electronic device 3. The gas detection system 1 as shown in FIG. 1 is also referred to as a "gas detection device."

[0013] The uses of the gas detection system 1 are not limited to those described above. For example, the gas detection system 1 may be installed in a refrigerator. In this case, the gas detection system 1 may acquire gases generated from food as sample gases. As another use, for example, the gas detection system 1 may be installed in a factory or laboratory. In this case, the gas detection system 1 may acquire gases generated from chemicals or the like as sample gases.

[0014] The toilet 2 can be installed in a toilet room in a home, a hospital, or the like. The toilet 2 can be used by a subject. As described above, the toilet 2 includes a toilet bowl 2A and a toilet seat 2B. The subject's feces can be excreted into the toilet bowl 2A.

[0015] 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. When the subject brings the electronic device 3 into the toilet room, the electronic device 3 may be located inside the toilet room as shown in FIG. 1 . However, when the subject does not bring the electronic device 3 into the toilet room, the electronic device 3 may be located outside the toilet room. The electronic device 3 may receive detection results from the gas detection system 1 via wireless or wired communication. The electronic device 3 may display the received detection results on the display unit 3A. The display unit 3A may include a display capable of displaying characters and the like and a touch screen capable of detecting touch by a user (subject)'s finger or the like. The display may include a display device such as a liquid crystal display (LCD), an organic electroluminescence display (OLED), or an inorganic electroluminescence 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, an ultrasonic method, an infrared method, an electromagnetic induction method, or a load detection method.

[0016] As shown in FIG. 2, the gas detection system 1 includes a housing 10, a suction hole 20, a suction hole 21, a discharge path 22, and flow paths 23A, 23B, 23C, 24A, 24B, 24C, 25A, 25B, 25C, 25D, 25E, and 25F. The gas detection system 1 includes a first chamber 30, a second chamber 32, a third chamber 33, a fourth chamber 35, a fifth chamber 37, valves 40, 41, 42, 43, 44, and 45, and supply units 50, 51, and 52. The gas detection system 1 includes multiple sensor units 34 within the third chamber 33. As shown in FIG. 3, the gas detection system 1 includes a circuit board 60. The gas detection system 1 includes a memory unit 61, a communication unit 62, and a control unit 64 within the circuit board 60. The gas detection system 1 includes a sensor unit 63. Furthermore, the gas detection system 1 may include a battery, a speaker, and the like.

[0017] The housing 10 accommodates various components of the gas detection 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.

[0018] As shown in FIG. 1, the suction hole 20 may be exposed to the inside of the toilet bowl 2A. A portion of the suction hole 20 may be embedded in the toilet seat 2B. The suction hole 20 draws in gas generated from feces discharged into the toilet bowl 2A as sample gas. The sample gas drawn by the suction hole 20 is supplied to and stored in the first chamber 30. As shown in FIG. 1, one end of the suction hole 20 may be directed toward the inside of the toilet bowl 2A. As shown in FIG. 2, the other end of the suction hole 20 may be connected to the first chamber 30. The suction hole 20 may be composed of a tubular member such as a resin tube or a metal or glass pipe.

[0019] As shown in FIG. 2, the suction hole 20 may have a blower 20A on its outside. The blower 20A may include a fan and a motor. The blower 20A may rotate the fan by driving the motor under the control of the control unit 64. By rotating the fan, the blower 20A draws gas generated from the feces into the vicinity of the suction hole 20. When the blower 20A draws the gas generated from the feces into the vicinity of the suction hole 20 and the supply unit 50 is further driven, the suction hole 20 can suck in the gas generated from the feces in the toilet bowl 2A.

[0020] As shown in FIG. 1, the suction hole 21 may be exposed to the outside of the toilet bowl 2A. A portion of the suction hole 21 may be embedded in the toilet seat 2B. The suction hole 21, for example, draws in the air (environmental gas) in the toilet room outside the toilet bowl 2A as purge gas. The purge gas drawn in by the suction hole 21 is supplied to the fourth chamber 35 via the flow paths 24A and 24C and stored therein. The purge gas drawn in by the suction hole 21 is supplied to the first chamber 30 via the flow paths 23A and 23B. As shown in FIG. 1, one end of the suction hole 21 may face the outside of the toilet bowl 2. As shown in FIG. 2, the other end of the suction hole 21 may be connected to one end of the flow path 23A and one end of the flow path 24A. The suction hole 21 may be formed of a tubular member such as a resin tube or a metal or glass pipe.

[0021] As shown in FIG. 2, the suction hole 21 may have a blower 21A on its outside. The blower 21A may include a fan and a motor. The blower 21A can rotate the fan by driving the motor under the control of the control unit 64. The blower 21A draws air from within the toilet room into the vicinity of the suction hole 21 by rotating the fan. The blower 21A draws air from within the toilet room into the vicinity of the suction hole 21, and then either the supply unit 51 or the supply unit 52 is driven, whereby the suction hole 21 can suck in the air from within the toilet room as purge gas.

[0022] The discharge path 22 as shown in FIG. 2 discharges exhaust air from the first chamber 30 to the outside via flow path 25A. The discharge path 22 discharges exhaust air from the second chamber 32 to the outside via flow paths 25B and 25F. The discharge path 22 discharges exhaust air from the third chamber 33 to the outside via flow paths 25E and 25F. The discharge path 22 discharges exhaust air from the fourth chamber 35 to the outside via flow paths 25D, 25E, and 25F. One end of the discharge path 22 is exposed from the toilet seat 2B as shown in FIG. 1. The other end of the discharge path 22 is connected to one end of flow path 25A and one end of flow path 25F as shown in FIG. 2. The discharge path 22 may be composed of a tubular member such as a resin tube or a metal or glass pipe.

[0023] 2, one end of flow path 23A is connected to suction hole 21 and one end of flow path 24A. The other end of flow path 23A is connected to one end of flow path 23B and one end of flow path 23C. One end of flow path 23B is connected to one end of flow path 23A and one end of flow path 23C. The other end of flow path 23B is connected to a connection port of valve 40. One end of flow path 23C is connected to one end of flow path 23A and one end of flow path 23B. The other end of flow path 23C is connected to a connection port of valve 41. Flow paths 23A to 23C may be formed of tubular members such as resin tubes or metal or glass piping.

[0024] 2, one end of flow path 24A is connected to suction hole 21 and one end of flow path 23A. The other end of flow path 24A is connected to one end of flow path 24B and one end of flow path 24C. One end of flow path 24B is connected to one end of flow path 24A and one end of flow path 24C. The other end of flow path 24B is connected to a connection port of valve 45. One end of flow path 24C is connected to one end of flow path 24A and one end of flow path 24B. The other end of flow path 24C is connected to a connection port of valve 44. Flow paths 24A to 24C may be formed of tubular members such as resin tubes or metal or glass piping.

[0025] As shown in FIG. 2, one end of flow path 25A is connected to a connection port of valve 41. The other end of flow path 25A is connected to discharge path 22 and one end of flow path 25F. One end of flow path 25B is connected to a connection port of valve 42. The other end of flow path 25B is connected to one end of flow path 25E and one end of flow path 25F. One end of flow path 25C is connected to a connection port of valve 43. The other end of flow path 25C is connected to one end of flow path 25D and one end of flow path 25E. One end of flow path 25D is connected to a connection port of valve 45. The other end of flow path 25D is connected to one end of flow path 25C and one end of flow path 25E. One end of flow path 25E is connected to one end of flow path 25C and one end of flow path 25D. The other end of flow path 25E is connected to one end of flow path 25B and one end of flow path 25F. One end of flow path 25F is connected to one end of flow path 25B and one end of flow path 25E. The other end of flow path 25F is connected to one end of flow path 25A and discharge path 22. Flow paths 25A to 25F may be configured with tubular members such as resin tubes or metal or glass piping.

[0026] The first chamber 30 as shown in Figure 2 may be cylindrical. The first chamber 30 may be linear. The first chamber 30 includes an inlet 30a and an outlet 30b at both ends. The first chamber 30 may be made of a material such as glass, metal, or resin.

[0027] Sample gas is supplied to the first chamber 30 shown in Figure 2 through the suction hole 20 (see Figure 4). The first chamber 30 can store the supplied sample gas. The sample gas supplied to the first chamber 30 can be supplied to the second chamber 32 (see Figure 5).

[0028] An adsorbent 31 may be disposed inside the first chamber 30. The adsorbent 31 may contain any material depending on the application. For example, the adsorbent 31 may contain at least one of activated carbon, silica gel, zeolite, and molecular sieve. The adsorbent 31 may be of multiple types, or may contain a porous material.

[0029] The adsorbent 31 may adsorb gases contained in the sample gas that are not to be detected. When the sample gas is a gas generated from feces, examples of specific gases that are not to be detected include ammonia and water. Examples of the adsorbent 31 that adsorbs gases that are not to be detected include silica gel and zeolite. The sample gas may also be concentrated in the first chamber 30. In this case, the adsorbent 31 may adsorb a gas that is to be detected that is contained in the sample gas. When the sample gas is a gas generated from feces, examples of specific gases that are to be detected include methane, hydrogen, carbon dioxide, methyl mercaptan, hydrogen sulfide, acetic acid, and trimethylamine. Examples of the adsorbent 31 that adsorbs a gas that is to be detected include activated carbon and molecular sieves. However, these combinations may be changed as appropriate depending on the polarity of the gas molecules to be adsorbed.

[0030] As shown in FIG. 2, the second chamber 32 is located between the first chamber 30 and the third chamber 33. In other words, the second chamber 32 is located between the first chamber 30 and the sensor unit 34. The second chamber 32 may be cylindrical. The second chamber 32 may be linear. The second chamber 32 includes an inlet 32a and an outlet 32b at both ends. In a cross section perpendicular to the gas flow direction of the first chamber 30, the area of ​​the second chamber 32 is smaller than the area of ​​the first chamber 30. In the present disclosure, the "gas flow direction of the first chamber 30" refers to the direction in which gas flows from the first chamber 30 to the second chamber 32. For example, the gas flow direction of the first chamber 30 may be the direction in which sample gas flows from the first chamber 30 to the second chamber 32, as shown in FIG. 5. In addition, in the present disclosure, the "area of ​​a chamber" refers to the area of ​​the portion of the chamber that contains gas, rather than the area of ​​the chamber itself. When both the first chamber 30 and the second chamber 32 are cylindrical, the cross-sectional area of ​​the second chamber 32 may be smaller than the cross-sectional area of ​​the first chamber 30. The second chamber 32 may be made of a material such as glass, metal, or resin.

[0031] After the sample gas is supplied from the first chamber 30 to the second chamber 32, a purge gas is supplied from the flow path 23C. The purge gas supplied from the flow path 23C to the second chamber 32 pushes the sample gas in the second chamber 32 into the third chamber 33 (see FIG. 7). With this configuration, the sample gas in the second chamber 32 is supplied to the third chamber 33 and then to the sensor unit 34.

[0032] The volume of the second chamber 32 may be equal to or less than the volume of the first chamber 30 and may be greater than the volume of the third chamber 33 in which the sensor unit 34 is disposed. By making the volume of the second chamber 32 equal to or less than the volume of the first chamber 30, the degree to which the sample gas is diluted by the purge gas in the first chamber 30 can be reduced. Furthermore, by making the volume of the second chamber 32 greater than the volume of the third chamber 33, the sample gas in the second chamber 32 can be supplied to the third chamber 33 at least once or multiple times.

[0033] As shown in FIG. 2, the third chamber 33 is located between the second chamber 32 and the flow path 25C. The third chamber 33 is cylindrical. The third chamber 33 may be linear. The third chamber 33 includes an inlet 33a and an outlet 33b at both ends. The sensor unit 34 is disposed in the third chamber 33. The third chamber 33 may be made of a material such as glass, metal, or resin.

[0034] Purge gas is supplied to the third chamber 33 from the fifth chamber 37 (see FIG. 6). Sample gas is supplied to the third chamber 33 from the second chamber 32 (see FIG. 7). The purge gas and sample gas supplied to the third chamber 33 are supplied to the sensor unit 34, and then discharged to the outside from the flow path 25C via the discharge path 22.

[0035] The sensor unit 34 shown in FIG. 2 is disposed within the third chamber 33. The sensor unit 34 outputs a voltage corresponding to the concentration of a specific gas to the control unit 64. The specific gas includes a specific gas to be detected and a specific gas that is not to be detected. When the sample gas is a gas generated from feces, examples of the specific gas to be detected include methane, hydrogen, carbon dioxide, methyl mercaptan, hydrogen sulfide, acetic acid, and trimethylamine. When the sample gas is a gas generated from feces, examples of the specific gas that is not to be detected include ammonia and water. Each of the multiple sensor units 34 can output a voltage corresponding to the concentration of at least one of these gases to the control unit 64. The sensor unit 34 may be configured to include any of a semiconductor sensor, a catalytic combustion sensor, an electrochemical sensor, or the like.

[0036] 2 is cylindrical. The fourth chamber 35 may be linear. The fourth chamber 35 includes an inlet 35a and an outlet 35b at both ends. The fourth chamber 35 may be made of a material such as glass, metal, or resin.

[0037] Purge gas is supplied to the fourth chamber 35 via the flow path 24C. The fourth chamber 35 can store the supplied purge gas. The purge gas supplied to the fourth chamber 35 can be supplied to the fifth chamber 37.

[0038] An adsorbent 36 may be disposed inside the fourth chamber 35. The adsorbent 36 may include any material depending on the application. For example, the adsorbent 36 may include at least one of activated carbon, silica gel, zeolite, and molecular sieve. The adsorbent 36 may be of multiple types or may include a porous material.

[0039] The adsorbent 36 may include one that adsorbs non-target gases mixed in the purge gas. Examples of the adsorbent 36 that adsorbs non-target gases include silica gel and zeolite. The adsorbent 36 may also include one that adsorbs target gases mixed in the purge gas. Examples of the adsorbent 36 that adsorbs target gases include activated carbon and molecular sieves. However, the combination of these may be changed as appropriate depending on the polarity of the gas molecules to be adsorbed. Here, if the air in the toilet room is contaminated, the purge gas may be contaminated with non-target gases and target gases. In this case, by disposing the adsorbent 36 in the fourth chamber 35, the contaminated air in the toilet room can be purified by the adsorbent 36. Purifying the air in the toilet room with the adsorbent 36 ensures a sufficient amount of purge gas in the fourth chamber 35.

[0040] As shown in FIG. 2, the fifth chamber 37 is located between the third chamber 33 and the fourth chamber 35. The fifth chamber 37 is cylindrical. The fifth chamber 37 may be linear. The fifth chamber 37 includes an inlet 37a and an outlet 37b at both ends. The fifth chamber 37 may be made of a material such as glass, metal, or resin.

[0041] 2, the valve 40 is located between the suction hole 20, the flow path 23B, and the inlet 30a of the first chamber 30. The valve 40 includes a connection port connected to the suction hole 20, a connection port connected to the flow path 23B, and a connection port connected to the inlet 30a. The valve 40 may be configured as an electromagnetically driven, piezoelectrically driven, motor-driven, or other valve.

[0042] The valve 40 switches the connection state between the suction hole 20, the flow path 23B, and the inlet 30a based on the control of the control unit 64. For example, the valve 40 switches the connection state among these to a state in which the suction hole 20 and the inlet 30a are connected, a state in which the flow path 23B and the inlet 30a are connected, or a state in which the suction hole 20, the flow path 23B, and the inlet 30a are not connected.

[0043] 2, valve 41 is located between flow path 23C, flow path 25A, outlet 30b of first chamber 30, and inlet 32a of second chamber 32. Valve 41 includes a connection port connected to flow path 23C, a connection port connected to flow path 25A, a connection port connected to outlet 30b, and a connection port connected to inlet 32a. Valve 41 may be configured as an electromagnetically driven, piezoelectrically driven, motor-driven, or other valve.

[0044] Valve 41 switches the connection state between flow path 23C, flow path 25A, outlet 30b, and inlet 32a based on the control of control unit 64. For example, valve 41 switches the connection state between these to a state in which flow path 23C and outlet 30b are connected, a state in which outlet 30b and inlet 32a are connected, or a state in which flow path 23C and inlet 32a are connected. Alternatively, valve 41 switches the connection state between these to a state in which flow path 23C, flow path 25A, outlet 30b, and inlet 32a are not connected.

[0045] 2, the valve 42 is located between the flow path 25B, the outlet 32b of the second chamber 32, the inlet 33a of the third chamber 33, and the outlet 37b of the fifth chamber 37. The valve 42 includes a connection port connected to the flow path 25B, a connection port connected to the outlet 32b, a connection port connected to the inlet 33a, and a connection port connected to the outlet 37b. The valve 42 may be an electromagnetically driven, piezoelectrically driven, motor-driven, or other type of valve.

[0046] Valve 42 switches the connection state between flow path 25B, outlet 32b, inlet 33a, and outlet 37b based on the control of control unit 64. For example, valve 42 switches the connection state between these to a state in which flow path 25B and outlet 32b are connected, a state in which inlet 33a and outlet 37b are connected, or a state in which outlet 32b and inlet 33a are connected. Alternatively, valve 42 switches the connection state between these to a state in which flow path 25B, outlet 32b, inlet 33a, and outlet 37b are not connected.

[0047] 2, valve 43 is located between flow path 25C and outlet 33b of third chamber 33. Valve 43 includes a connection port connected to flow path 25C and a connection port connected to outlet 33b. Valve 43 may be configured as an electromagnetically driven, piezoelectrically driven, motor-driven, or other valve.

[0048] The valve 43 switches the connection state between the flow path 25C and the outlet 33b based on the control of the control unit 64. For example, the valve 43 switches the connection state between the flow path 25C and the outlet 33b between a state in which the flow path 25C and the outlet 33b are connected and a state in which the flow path 25C and the outlet 33b are not connected.

[0049] 2, the valve 44 is located between the flow path 24C and the inlet 35a of the fourth chamber 35. The valve 44 includes a connection port connected to the flow path 24C and a connection port connected to the inlet 35a. The valve 44 may be configured as an electromagnetically driven, piezoelectrically driven, motor-driven, or other valve.

[0050] The valve 44 switches the connection state between the flow path 24C and the inlet 35a based on the control of the control unit 64. For example, the valve 44 switches the connection state between the flow path 24C and the inlet 35a between a state in which the flow path 24C and the inlet 35a are connected and a state in which the flow path 24C and the inlet 35a are not connected.

[0051] 2, valve 45 is located between flow path 24B, flow path 25D, outlet 35b of fourth chamber 35, and inlet 37a of fifth chamber 37. Valve 45 includes a connection port connected to flow path 24B, a connection port connected to flow path 25D, a connection port connected to outlet 35b, and a connection port connected to inlet 37a. Valve 45 may be configured as an electromagnetically driven, piezoelectrically driven, motor-driven, or other valve.

[0052] The valve 45 switches the connection state between the flow path 24B, the flow path 25D, the outlet 35b, and the inlet 37a based on the control of the control unit 64. For example, the valve 45 switches the connection state between these to a state in which the outlet 35b and the inlet 37a are connected, a state in which the flow path 25D and the outlet 35b are connected, a state in which the flow path 24B and the inlet 37a are connected, or a state in which the flow path 24B and the flow path 25D are connected. Alternatively, the valve 45 switches the connection state between these to a state in which the flow path 24B, the flow path 25D, the outlet 35b, and the inlet 37a are not connected.

[0053] 2 is attached to the suction hole 20. The supply unit 50 is capable of supplying sample gas from the suction hole 20 to the first chamber 30 under the control of the control unit 64. The arrow shown on the supply unit 50 indicates the direction in which the supply unit 50 sends the sample gas. The supply unit 50 may be configured as a piezo pump, a motor pump, or the like.

[0054] 2 is attached to flow path 24A. Based on the control of control unit 64, supply unit 51 can supply purge gas from suction hole 21 to at least one of flow path 24B and flow path 24C. The arrow shown on supply unit 51 indicates the direction in which supply unit 51 sends the purge gas. Supply unit 51 may be configured with a piezo pump or the like.

[0055] 2 is attached to flow path 23A. Based on the control of control unit 64, supply unit 52 supplies purge gas from suction hole 21 to at least one of flow path 23B and flow path 23C. The arrow shown on supply unit 52 indicates the direction in which supply unit 52 sends the purge gas. Supply unit 52 may be configured with a piezo pump or the like.

[0056] A circuit board 60 as shown in FIG. 3 is equipped with wiring for transmitting electrical signals, a storage unit 61, a communication unit 62, a control unit 64, and the like.

[0057] 3 is configured with, for example, a semiconductor memory or a magnetic memory. The storage unit 61 stores various types of information and programs for operating the gas detection system 1. The storage unit 61 may function as a work memory.

[0058] The communication unit 62 as shown in FIG. 3 is capable of communicating with the electronic device 3 as shown in FIG. 1. The communication unit 62 may be capable of communicating with an external server. A communication method used in communication between the communication unit 62 and the electronic device 3 and the external server may be a short-range wireless communication standard, a wireless communication standard connecting to a mobile phone network, or a wired communication standard. The short-range wireless communication standard may include, for example, Wi-Fi (registered trademark), Bluetooth (registered trademark), infrared, and NFC (Near Field Communication). The wireless communication standard connecting to a mobile phone network may include, for example, LTE (Long Term Evolution) or a fourth-generation or higher mobile communication system. Furthermore, the communication method used in communication between the communication unit 62 and the electronic device 3 and the external server may be, for example, a communication standard such as LPWA (Low Power Wide Area) or LPWAN (Low Power Wide Area Network).

[0059] 3 may be configured to include at least 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.

[0060] For example, if the sensor unit 63 is configured to include an infrared sensor, it can detect that the subject has entered the toilet room by detecting the reflected light of the infrared light irradiated by the infrared sensor from the object. As a detection result, the sensor unit 63 outputs a signal indicating that the subject has entered the toilet room to the control unit 64.

[0061] For example, if the sensor unit 63 is configured to include a pressure sensor, it can detect that the subject has sat on the toilet seat 2B by detecting the pressure applied to the toilet seat 2B as shown in Fig. 1. As a detection result, the sensor unit 63 outputs a signal indicating that the subject has sat on the toilet seat 2B to the control unit 64.

[0062] For example, if the sensor unit 63 is configured to include a pressure sensor, it can detect that the subject has stood up from the toilet seat 2B by detecting a decrease in pressure on the toilet seat 2B as shown in Fig. 1. As a detection result, the sensor unit 63 outputs a signal indicating that the subject has stood up from the toilet seat 2B to the control unit 64.

[0063] For example, if the sensor unit 63 is configured to include an image camera, a personal identification switch, etc., it collects data such as facial images, sitting height, and weight. The sensor unit 63 identifies and detects individuals from the collected data. As a detection result, the sensor unit 63 outputs a signal indicating the identified individual to the control unit 64.

[0064] For example, if the sensor unit 63 is configured to include a personal identification switch or the like, it identifies (detects) an individual based on the operation of the personal identification switch. In this case, personal information may be registered (stored) in advance in the storage unit 61. The sensor unit 63 outputs a signal indicating the identified individual to the control unit 64 as the detection result.

[0065] The control unit 64 as shown in FIG. 3 includes one or more processors. The processor may include at least one of a general-purpose processor that loads a specific program to execute a specific function and 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 one of a system-on-a-chip (SoC) and a system-in-a-package (SiP) in which one or more processors work together.

[0066] The control unit 64 controls the suction hole 21 shown in FIG. 2 to suck air in the toilet room as purge gas. The control unit 64 controls the suction hole 21 shown in FIG. 2 to store the purge gas in the fourth chamber 35. For example, the control unit 64 rotates the fan of the blower 21A shown in FIG. 2 to draw the purge gas near the suction hole 21. Furthermore, the control unit 64 connects the flow path 24C to the inlet 35a of the fourth chamber 35 using the valve 44, and connects the outlet 35b of the fourth chamber 35 to the flow path 25D using the valve 45. In addition, the control unit 64 controls the supply unit 51 to suck the purge gas drawn near the suction hole 21 by the blower 21A into the suction hole 21. The purge gas drawn by the suction hole 21 is supplied to the fourth chamber 35 via the flow paths 24A and 24C and stored therein. The control unit 64 may cause the suction hole 21 to suck in the purge gas after a predetermined time has elapsed since it was detected that the subject has stood up from the toilet seat 2B based on the detection result of the sensor unit 63.

[0067] When the purge gas is sucked into the suction hole 21, the control unit 64 may store the purge gas in the fourth chamber 35 if the cleanliness of the purge gas is high. For example, the control unit 64 may supply the purge gas to the sensor unit 34 of the third chamber 33 and determine whether the cleanliness of the purge gas is high based on the detection result of the sensor unit 34. When the control unit 64 determines that the cleanliness of the purge gas is high, the control unit 64 may store the purge gas in the fourth chamber 35. In this case, the gas detection system 1 may further include a flow path directly connecting the suction hole 21 and the third chamber 33, and an exhaust path directly exhausting the gas supplied to the third chamber 33 to the outside. Furthermore, the gas detection system 1 may further include a dedicated sensor unit for detecting the cleanliness of the purge gas, separate from the sensor unit 34. The dedicated sensor unit may be provided at the tip of the suction hole 21 as shown in FIG. 2 or between the suction hole 21 and the fourth chamber 35. In this case, the gas detection system 1 may further include an exhaust path for directly exhausting the gas supplied to the dedicated sensor unit to the outside.

[0068] The control unit 64 controls the suction hole 20 as shown in Fig. 2 to suck in the sample gas. For example, the control unit 64 rotates the fan of the blower 20A as shown in Fig. 2 to suck in the sample gas near the suction hole 20. The control unit 64 controls the supply unit 50 to suck the sample gas drawn into the suction hole 20 into the suction hole 20. The control unit 64 may cause the suction hole 20 to suck in the sample gas after a predetermined time has elapsed since it was detected that the subject has sat on the toilet seat 2B based on the detection result of the sensor unit 63.

[0069] The control unit 64 controls the sample gas drawn into the suction hole 20 so that it accumulates in the first chamber 30. For example, the control unit 64 connects the suction hole 20 to the inlet 30a of the first chamber 30 using a valve 40 as shown in FIG. 4. Furthermore, the control unit 64 connects the outlet 30b of the first chamber 30 to the flow path 25A using a valve 41 as shown in FIG. 4. The control unit 64 controls the supply unit 50 as shown in FIG. 2 to supply the sample gas from the suction hole 20 as shown in FIG. 2 to the first chamber 30 as shown in FIG. 4. The sample gas supplied from the suction hole 20 to the first chamber 30 via the inlet 30a pushes the residual gas in the first chamber 30 toward the outlet 30b. The residual gas pushed toward the outlet 30b is discharged from the flow path 25A to the outside via the exhaust path 22 as shown in FIG. 2. With this configuration, the sample gas accumulates in the first chamber 30 as shown in FIG. 4.

[0070] The control unit 64 controls the sample gas stored in the first chamber 30 to be supplied to the second chamber 32. For example, the control unit 64 connects the flow path 23B to the inlet 30a of the first chamber 30 using a valve 40 as shown in FIG. 5, and connects the outlet 30b of the first chamber 30 to the inlet 32a of the second chamber 32 using a valve 41 as shown in FIG. 5. Furthermore, the control unit 64 connects the outlet 32b of the second chamber 32 to the flow path 25B using a valve 42 as shown in FIG. 5. In addition, the control unit 64 controls the supply unit 52 as shown in FIG. 2 to supply purge gas from the suction hole 21 as shown in FIG. 2 to the first chamber 30 via the flow path 23B as shown in FIG. 5. The purge gas supplied from the flow path 23B to the first chamber 30 via the inlet 30a pushes the sample gas in the first chamber 30 toward the outlet 30b. The sample gas pushed out toward the outlet 30b is supplied to the second chamber 32 via the inlet 32a. The sample gas supplied to the second chamber 32 pushes the residual gas in the second chamber 32 out toward the outlet 32b. The residual gas pushed out toward the outlet 32b is discharged to the outside from the flow path 25B via the discharge path 22 as shown in FIG. 2. With this configuration, the sample gas stored in the first chamber 30 is supplied to the second chamber 32 as shown in FIG.

[0071] The control unit 64 controls the purge gas stored in the fourth chamber 35 to be supplied to the sensor unit 34 of the third chamber 33. For example, the control unit 64 connects the flow path 24D and the inlet 35a of the fourth chamber 35 using a valve 44 as shown in FIG. 6, and connects the outlet 35b of the fourth chamber 35 and the inlet 37a of the fifth chamber 37 using a valve 45 as shown in FIG. 6. Furthermore, the control unit 64 connects the inlet 33a of the third chamber 33 and the outlet 37b of the fifth chamber 37 using a valve 42 as shown in FIG. 6, and connects the outlet 33b of the third chamber 33 and the flow path 25C using a valve 43 as shown in FIG. 6. In addition, the control unit 64 controls the supply unit 51 as shown in FIG. 2 to supply the purge gas from the suction hole 21 as shown in FIG. 2 to the fourth chamber 35 as shown in FIG. 6. The purge gas supplied to the fourth chamber 35 through the suction hole 21 pushes the purge gas stored in the fourth chamber 35 into the fifth chamber 37. The purge gas pushed out to the fifth chamber 37 is supplied to the third chamber 33. The purge gas supplied from the fifth chamber 37 to the third chamber 33 through the inlet 33a is supplied to the sensor unit 34 in the third chamber 33. When the purge gas is supplied to the sensor unit 34, the sensor unit 34 outputs a voltage corresponding to the specific gas contained in the purge gas to the control unit 64. After the detection process, the purge gas is discharged to the outside from the outlet 33b and the flow path 25C via the discharge path 22 as shown in FIG. 2.

[0072] The control unit 64 controls the supply of sample gas to the sensor unit 34 of the third chamber 33. For example, the control unit 64 connects the flow path 23C and the inlet 32a of the second chamber 32 using a valve 41 as shown in FIG. 7, and connects the outlet 32b of the second chamber 32 and the inlet 33a of the third chamber 33 using a valve 42 as shown in FIG. 7. Furthermore, the control unit 64 connects the outlet 33b of the third chamber 33 and the flow path 25C using a valve 43 as shown in FIG. 7. In addition, the control unit 64 controls the supply unit 52 as shown in FIG. 2 to supply purge gas from the suction hole 21 as shown in FIG. 2 to the second chamber 32 through the flow path 23C as shown in FIG. 7. The purge gas supplied from the flow path 23C to the second chamber 32 via the inlet 32a pushes the sample gas in the second chamber 32 toward the outlet 32b. The sample gas pushed out toward outlet 32b is supplied from inlet 33a via outlet 32b to third chamber 33. The sample gas supplied to third chamber 33 is then supplied to sensor unit 34. When sample gas is supplied to sensor unit 34, sensor unit 34 outputs a voltage corresponding to the specific gas contained in the sample gas to control unit 64. After detection processing, the sample gas is discharged to the outside from outlet 33b and flow path 25C via discharge path 22 as shown in FIG. 2.

[0073] The control unit 64 alternately supplies the purge gas and the sample gas to the sensor unit 34 of the third chamber 33, for example, a predetermined number of times. For example, the control unit 64 alternately repeats the control described with reference to FIG. 6 and the control described with reference to FIG. 7, for example, a predetermined number of times. The control unit 64 acquires a voltage waveform from the sensor unit 34 by alternately supplying the purge gas and the sample gas to the third chamber 33. The control unit 64 detects the type and concentration of gas contained in the sample gas, for example, by machine learning on the voltage waveform acquired from the sensor unit 34. The control unit 64 may transmit the detected type and concentration of gas as a detection result to the electronic device 3 via the communication unit 62.

[0074] The control unit 64 controls the first chamber 30 so that the sample gas remaining in the first chamber 30 is discharged from the first chamber 30, for example, after the detection process. For example, the control unit 64 connects the flow path 23B to the inlet 30a of the first chamber 30 using a valve 40 as shown in FIG. 8, and connects the outlet 30b of the first chamber 30 to the flow path 25A using a valve 41 as shown in FIG. 8. Furthermore, the control unit 64 controls the supply unit 52 as shown in FIG. 2 to supply purge gas from the suction hole 21 as shown in FIG. 2 to the first chamber 30 from the flow path 23B as shown in FIG. 8. The purge gas supplied from the flow path 23B to the first chamber 30 via the inlet 30a pushes the sample gas remaining in the first chamber 30 toward the outlet 30b. The sample gas pushed toward the outlet 30b is discharged from the flow path 25A to the outside via the exhaust path 22 as shown in FIG. 2.

[0075] Here, the control unit 64 can control the flow rate of the sample gas supplied to the third chamber 33. In other words, the control unit 64 can control the flow rate of the sample gas supplied to the sensor unit 34. For example, the control unit 64 controls the flow rate of the purge gas supplied to the second chamber 32 from the flow path 23C as shown in FIG. 7 by using a piezo pump or motor pump of the supply unit 52 as shown in FIG. 2. The control unit 64 controls the flow rate of the purge gas supplied to the second chamber 32 as shown in FIG. 7, thereby controlling the flow rate of the sample gas pushed from the second chamber 32 to the third chamber 33 by the purge gas. The control unit 64 may appropriately control the flow rate of the sample gas when supplying the sample gas to the third chamber 33 and then to the sensor unit 34.

[0076] The control unit 64 may control the flow rate of the sample gas at the start of supply to the sensor unit 34 so that it is greater than the first flow rate. The flow rate at the start of supply to the sensor unit 34 may be determined appropriately, taking into consideration the effect on the output voltage of the sensor unit 34 when the gas supplied to the sensor unit 34 is switched from purge gas to sample gas. Here, when the gas supplied to the sensor unit 34 is switched from purge gas to sample gas or from sample gas to purge gas, the output voltage of the sensor unit 34 may fall or rise and then become a constant value. The greater the flow rate at the start of supply to the sensor unit 34, the more likely this fall or rise of the output voltage of the sensor unit 34 is to be due to a reaction of the sensor unit 34 itself. The more the output voltage of the sensor unit 34 is due to a reaction of the sensor unit 34 itself, the more accurately the gas detection system 1 can detect the type and concentration of gas. That is, by making the flow rate of the sample gas at the start of supply to the sensor unit 34 larger than the first flow rate, the output voltage of the sensor unit 34 can approach that due to the reaction of the sensor unit 34 itself. With this configuration, the gas detection system 1 can detect the type and concentration of gas with higher accuracy.

[0077] The control unit 64 may control the flow rate of the sample gas to be smaller than the flow rate at the start of the supply of the sample gas to the sensor unit 34 after a first hour has elapsed since the start of the supply of the sample gas to the sensor unit 34. Alternatively, the control unit 64 may stop the supply of the sample gas to the sensor unit 34 after a first hour has elapsed since the start of the supply of the sample gas to the sensor unit 34. For example, the control unit 64 may control the supply unit 52 shown in FIG. 2 so that the flow rate of the purge gas supplied from the flow path 23C shown in FIG. 7 to the second chamber 32 is smaller than the flow rate at the start of the supply of the purge gas after the first hour has elapsed. By reducing the flow rate of the purge gas supplied from the flow path 23C shown in FIG. 7 to the second chamber 32, the flow rate of the sample gas pushed from the second chamber 32 to the third chamber 33 shown in FIG. 7 by the purge gas can be reduced. Alternatively, after the first time period has elapsed, the control unit 64 may control the supply unit 52 shown in FIG. 2 to stop the supply of purge gas from the flow path 23C to the second chamber 32 shown in FIG. 7. Stopping the supply of purge gas from the flow path 23C to the second chamber 32 shown in FIG. 7 may stop the supply of sample gas from the second chamber 32 to the third chamber 33 shown in FIG. 7. Here, the sample gas is gas generated from feces. Therefore, the amount of sample gas that can be obtained may be limited. In particular, the amount of sample gas decreases when the sample gas is concentrated. Even in this case, the control unit 64 can continue to supply the sample gas to the sensor unit 34 for a longer period than when the flow rate is not reduced by, for example, reducing the flow rate of the sample gas after the first time period has elapsed compared to the flow rate at the start of the sample gas supply. This configuration allows the sensor unit 34 to stably output a voltage corresponding to the specific gas contained in the sample gas. The first time period may be appropriately set taking into account the amount of sample gas that can be stored in the first chamber 30.

[0078] After the above-mentioned first time period has elapsed, the control unit 64 may perform control such that a reduction in the flow rate of the sample gas and a stoppage of the supply of the sample gas to the sensor unit 34 are alternately repeated. In this case, the control unit 64 may perform control such that a reduction in the flow rate of the sample gas and a stoppage of the supply of the sample gas to the sensor unit 34 are alternately repeated according to the amount of sample gas stored in the first chamber 30.

[0079] Here, the control unit 64 can control the flow rate of the purge gas supplied to the third chamber 33. In other words, the control unit 64 can control the flow rate of the purge gas supplied to the sensor unit 34. For example, the control unit 64 controls the flow rate of the purge gas supplied to the third chamber 33 by controlling the flow rate of the purge gas supplied from the fifth chamber 37 as shown in FIG. 6 to the third chamber 33 using a piezo pump of the supply unit 51 as shown in FIG. 2. The control unit 64 may appropriately control the flow rate of the purge gas when supplying the purge gas to the sensor unit 34 of the third chamber 33.

[0080] The control unit 64 may control the flow rate of the purge gas at the start of supply to the sensor unit 34 to be greater than the second flow rate. Similar to the first flow rate described above, the flow rate at the start of supply to the sensor unit 34 may be appropriately determined taking into consideration the effect on the output voltage of the sensor unit 34 of switching the gas supplied to the sensor unit 34. As described above, when switching the gas supplied to the sensor unit 34, the output voltage of the sensor unit 34 either rises or falls. The greater the flow rate at the start of supply to the sensor unit 34, the closer this fall or rise in the output voltage is to a reaction of the sensor unit 34 itself. As described above, the closer the output voltage of the sensor unit 34 is to a reaction of the sensor unit 34 itself, the more accurately the gas detection system 1 can detect the type and concentration of the gas. In other words, similar to the first flow rate described above, by setting the flow rate of the purge gas at the start of supply to the sensor unit 34 greater than the second flow rate, the output voltage of the sensor unit 34 can be closer to a reaction of the sensor unit 34 itself. With this configuration, the gas detection system 1 can detect the type and concentration of gas with higher accuracy.

[0081] The control unit 64 may control the flow rate of the purge gas to be equal to or lower than the flow rate at the start of the supply of purge gas to the sensor unit 34 after a second time has elapsed since the start of the supply of purge gas to the sensor unit 34. Alternatively, the control unit 64 may stop the supply of purge gas to the sensor unit 34 after the second time has elapsed. For example, the control unit 64 may control the supply unit 51 shown in FIG. 2 after the second time has elapsed, thereby controlling the flow rate of the purge gas supplied from the fifth chamber 37 to the third chamber 33 as shown in FIG. 6 to be equal to or lower than the flow rate at the start of the supply of purge gas. Alternatively, the control unit 64 may control the supply unit 51 shown in FIG. 2 after the second time has elapsed, thereby stopping the supply of purge gas from the fifth chamber 37 to the third chamber 33 as shown in FIG. 7. Here, when the gas detection system 1 is installed in a toilet room, the air in the toilet room may be contaminated. In this case, the amount of purge gas that can be obtained may be limited. Even in this case, the control unit 64 can continue to supply the purge gas to the sensor unit 34 for a longer period of time than when the flow rate is not reduced, for example, by reducing the flow rate of the purge gas after the second time has elapsed to a value equal to or lower than the flow rate at the start of the purge gas supply. With this configuration, the sensor unit 34 can stably output a voltage corresponding to the specific gas contained in the purge gas. The second time period may be set appropriately taking into account the amount of purge gas that can be stored in the fourth chamber 35.

[0082] The control unit 64 may control the flow rate of the purge gas supplied to the sensor unit 34 so that it is greater than the flow rate of the sample gas supplied to the sensor unit 34. For example, the control unit 64 may control the flow rate of the purge gas supplied to the third chamber 33 via the fourth chamber 35 and the fifth chamber 37 as shown in FIG. 6 so that it is greater than the flow rate of the sample gas supplied from the second chamber 32 to the third chamber 33 as shown in FIG. 7. The amount of sample gas generated from feces may be more limited than the amount of purge gas, which is the air in the toilet room. In particular, the amount of sample gas decreases when the sample gas is concentrated. Furthermore, by increasing the flow rate of the purge gas, the target gas attached to the sensor unit 34 by the purge gas can be more quickly removed from the sensor unit 34. With this configuration, the gas detection system 1 can conserve sample gas while quickly removing the target gas attached to the sensor unit 34 from the sensor unit 34.

[0083] The control unit 64 may control the flow rate of the purge gas supplied to the first chamber 30 via the flow path 23B as shown in Fig. 5 so that it is greater than the flow rate of the purge gas supplied to the second chamber 32 from the flow path 23B as shown in Fig. 7. Increasing the flow rate of the purge gas supplied to the first chamber 30 from the flow path 23B as shown in Fig. 5 can reduce mutual diffusion of the sample gas and the purge gas within the first chamber 30. Furthermore, increasing the flow rate of the purge gas supplied to the first chamber 30 from the flow path 23B as shown in Fig. 5 can supply the sample gas to the second chamber 32 in a shorter time.

[0084] [Example of gas detection system operation] Fig. 9 is a flowchart showing the operation of the gas detection system 1 shown in Fig. 1. The control unit 64 may start the processing shown in Fig. 9 after a predetermined time has elapsed since it was detected that the subject has stood up from the toilet seat 2B based on the detection result of the sensor unit 63.

[0085] The control unit 64 controls the suction hole 21 to suck in the purge gas (step S10). The control unit 64 controls the suction hole 21 to store the purge gas in the fourth chamber 35 (step S11).

[0086] The control unit 64 controls the suction hole 20 to suck in the sample gas after a predetermined time has elapsed since it was detected that the subject sat on the toilet seat 2B based on the detection result of the sensor unit 63 (step S12). The control unit 64 controls the sample gas from the suction hole 20 to be stored in the first chamber 30 (step S13) (see FIG. 4). The control unit 64 controls the sample gas stored in the first chamber 30 to be supplied to the second chamber 32 (step S14) (see FIG. 5).

[0087] The control unit 64 controls the supply of purge gas to the third chamber 33 via the fifth chamber 37 (step S15) (see FIG. 6). That is, in the process of step S15, the control unit 64 controls the supply of purge gas to the sensor unit 34. Details of the process of step S15 will be described later with reference to FIG.

[0088] The control unit 64 controls the sample gas to be supplied to the third chamber 33 (step S16) (see FIG. 7). That is, in the process of step S16, the control unit 64 controls the sample gas to be supplied to the sensor unit 34. Details of the process of step S16 will be described later with reference to FIG.

[0089] The control unit 64 alternately executes the process of step S15 and the process of step S16, for example, a predetermined number of times. The control unit 18 acquires a voltage waveform from the sensor unit 34 (step S17).

[0090] The control unit 64 detects the type and concentration of gas contained in the sample gas, for example, by machine learning on the voltage waveform acquired from the sensor unit 34 (step S18). In the processing of step S18, the control unit 64 may transmit the detected type and concentration of gas as a detection result to the electronic device 3 via the communication unit 62.

[0091] As described above with reference to FIG. 8, the control unit 64 controls the sample gas remaining in the first chamber 30 so that it is discharged from the first chamber 30 (step S19).

[0092] After completing the process of step S14, the control unit 64 may execute the process of step S18 in parallel with the process of step S15.

[0093] Fig. 10 is a flowchart showing the operation of the gas detection system 1 shown in Fig. 1 when supplying purge gas. The process shown in Fig. 10 corresponds to details of the process of step S15 shown in Fig. 9. The control unit 64 may start the process shown in Fig. 10 after executing the process of step S14 shown in Fig. 9.

[0094] The control unit 64 controls the supply of the purge gas to the third chamber 33 at a flow rate greater than the second flow rate (step S30). In other words, the control unit 64 controls the flow rate of the purge gas at the start of supply to the sensor unit 34 to be greater than the second flow rate.

[0095] The control unit 64 determines whether a second time has elapsed since the supply of purge gas to the sensor unit 34 started (step S31). When the control unit 64 determines that the second time has elapsed since the supply of purge gas to the sensor unit 34 started (step S31: Yes), the control unit 64 proceeds to the processing of step S32. On the other hand, when the control unit 64 does not determine that the second time has elapsed since the supply of purge gas to the sensor unit 34 started (step S31: No), the control unit 64 repeatedly executes the processing of step S31.

[0096] In the process of step S32, the control unit 64 controls the flow rate of the purge gas so that it is equal to or lower than the flow rate at the start of the supply of the purge gas, or stops the supply of the purge gas to the sensor unit .

[0097] Fig. 11 is a flowchart showing the operation of the gas detection system 1 shown in Fig. 1 when supplying sample gas. The process shown in Fig. 11 corresponds to details of the process of step S16 shown in Fig. 9. The control unit 64 may start the process shown in Fig. 11 after executing the process of step S15 shown in Fig. 9.

[0098] The control unit 64 controls the sample gas to be supplied to the third chamber 33 at a flow rate greater than the first flow rate (step S40). In other words, the control unit 64 controls the flow rate at the start of supply of the sample gas to the sensor unit 34 to be greater than the first flow rate.

[0099] The control unit 64 determines whether a first time has elapsed since the supply of sample gas to the sensor unit 34 started (step S41). When the control unit 64 determines that the first time has elapsed since the supply of sample gas to the sensor unit 34 started (step S41: Yes), the control unit 64 proceeds to the processing of step S42. On the other hand, when the control unit 64 does not determine that the first time has elapsed since the supply of sample gas to the sensor unit 34 started (step S41: No), the control unit 64 repeatedly executes the processing of step S41.

[0100] In the process of step S42, the control unit 64 controls the flow rate of the sample gas to be smaller than the flow rate at the start of the supply of the sample gas, or stops the supply of the sample gas to the sensor unit 34.

[0101] As described above, in the gas detection system 1 according to this embodiment, the area of ​​the second chamber 32 is smaller than the area of ​​the first chamber 30 in a cross section perpendicular to the gas flow direction of the first chamber 30. Here, the purge gas and the sample gas can come into contact with each other in the second chamber 32 by implementing, for example, the configuration shown in FIG. 5 and the configuration shown in FIG. 7 . In this embodiment, by making the area of ​​the second chamber 32 smaller than the area of ​​the first chamber 30 in a cross section perpendicular to the gas flow direction of the first chamber 30, the area of ​​the boundary where the purge gas and the sample gas come into contact can be reduced. By reducing the area of ​​the boundary where the purge gas and the sample gas come into contact, it is possible to make it difficult for the purge gas and the sample gas to mix in the second chamber 32. As described above, in this embodiment, by making the cross-sectional area of ​​the second chamber 32 smaller than the cross-sectional area of ​​the first chamber 30, it is possible to make it difficult for the purge gas and the sample gas to mix in the second chamber 32. In this embodiment, the purge gas and the sample gas are less likely to mix, so the type and concentration of the gas can be detected with higher accuracy.

[0102] Furthermore, in the gas detection system 1 according to this embodiment, the control unit 64 controls the flow rate of the sample gas to the sensor unit 34 so that the flow rate after a first time has elapsed since the start of the supply of the sample gas to the sensor unit 34 is smaller than the flow rate at the start of the supply of the sample gas. Alternatively, the control unit 64 stops the supply of the sample gas to the sensor unit 34 after the first time has elapsed. As described above, the sample gas is a gas generated from feces. Therefore, the amount of sample gas that can be obtained may be limited. In particular, the amount of sample gas decreases when the sample gas is concentrated. Even in this case, the control unit 64 can continue to supply the sample gas to the sensor unit 34 for a longer period of time than when the flow rate is not reduced, for example, by reducing the flow rate of the sample gas after the first time has elapsed compared to the flow rate at the start of the supply of the sample gas. This configuration allows the sensor unit 34 to stably output a voltage corresponding to the specific gas contained in the sample gas. Because the sensor unit 34 can stably output a voltage, the gas detection system 1 can more accurately detect the type and concentration of the gas. Furthermore, with this configuration, the gas detection system 1 can detect the type and concentration of gas even with a small amount of sample gas. This allows the size of the gas detection system 1 to be reduced. In other words, the gas detection system 1 can be made smaller while maintaining detection accuracy.

[0103] Therefore, according to this embodiment, an improved gas detection system 1 can be provided.

[0104] The drawings illustrating the embodiments of the present disclosure are schematic, and the dimensional ratios and the like in the drawings do not necessarily correspond to the actual ones.

[0105] Although the embodiments of the present disclosure have been described based on the drawings and examples, it should be noted that those skilled in the art would easily be able to make various modifications or alterations based on the present disclosure. Therefore, it should be noted that these modifications and alterations are included within the scope of the present disclosure. For example, the functions included in each component may be rearranged so as not to cause logical inconsistencies, and multiple components may be combined or divided into one.

[0106] For example, in the above-described embodiment, the second chamber 32 has been described as extending along a straight line as shown in FIG. 2. However, the second chamber of the present disclosure is not limited to extending along a straight line. For example, the second chamber of the present disclosure may have a shape as shown in FIG. 12. The second chamber 132 as shown in FIG. 12 has a curved portion. The shape of the curved portion is, for example, a serpentine shape. The second chamber 132 includes an inlet 132a and an outlet 132b at both ends. The inlet 132a can be connected to the outlet 30b of the first chamber 30 as shown in FIG. 2. The outlet 132b can be connected to the inlet 33a of the third chamber 33 as shown in FIG. 2. The cross-sectional area of ​​the second chamber 132 as shown in FIG. 12 is smaller than the cross-sectional area of ​​the first chamber 30 as shown in FIG. 2. The second chamber 132 as shown in FIG. 12 can have a cross-sectional area that is smaller than the cross-sectional area of ​​the first chamber 30 while maintaining its volume and the occupied volume of the second chamber 132 by having a curved portion, for example, by having a serpentine shape.

[0107] For example, in the above embodiment, the first chamber 30 shown in FIG. 2 has been described as storing sample gas as shown in FIG. 4. However, the use of the first chamber 30 is not limited to this. The first chamber 30 may be used to concentrate the sample gas. In this case, the adsorbent 31 may adsorb the target gas contained in the sample gas. Examples of the adsorbent 31 that adsorbs the target gas include activated carbon and molecular sieves. However, the combination of these may be changed as appropriate depending on the polarity of the gas molecules to be adsorbed. Furthermore, a heater may be provided on the outside of the first chamber 30.

[0108] For example, in the above-described embodiment, the configuration of the gas detection system 1 is described as being as shown in Fig. 2. However, the configuration of the gas detection system 1 is not limited to the configuration shown in Fig. 2. For example, the gas detection system 1 may have configurations such as those shown in Figs. 13 to 17.

[0109] 13 includes a flow path 26 instead of the fourth chamber 35 and the fifth chamber 37 shown in FIG. 2. The gas detection system 1A includes a supply unit 50 and supply units 53A, 53B, and 53C as the supply unit. The flow path 26 directly connects the suction hole 21 shown in FIG. 2 with the connection port of the valve 42. The flow path 26 may be configured as a tubular member such as a resin tube or a metal or glass pipe. The supply unit 53A is attached to the flow path 23B. The supply unit 53B is attached to the flow path 23C. The supply unit 53C is attached to the flow path 26. The arrows on each of the supply units 53A to 53C indicate the direction in which the respective supply units 53A to 53C send gas. Each of the supply units 53A to 53C may be configured as a piezo pump, a motor pump, or the like.

[0110] 13, the control unit 64 connects the flow path 23B and the inlet 30a of the first chamber 30 using the valve 40, and controls the supply unit 53A to supply the purge gas from the suction hole 21 shown in FIG. 2 to the first chamber 30. The control unit 64 also connects the flow path 23C and the inlet 32a of the second chamber 32 using the valve 41, and controls the supply unit 53B to supply the purge gas from the suction hole 21 shown in FIG. 2 to the second chamber 32. The control unit 64 also connects the flow path 26 and the inlet 33a of the third chamber 33 using the valve 42, and controls the supply unit 53C to supply the purge gas from the suction hole 21 shown in FIG. 2 to the third chamber 33.

[0111] 14 includes flow paths 23D, 23E, and 23F instead of flow path 23C, fourth chamber 35, and fifth chamber 37 as shown in FIG. 2. Gas detection system 1B includes supply units 50 and 54 as supply units. One end of flow path 23D is connected to one end of flow path 23A and one end of flow path 23B. The other end of flow path 23D is connected to one end of flow path 23E and one end of flow path 23F. One end of flow path 23E is connected to one end of flow path 23D and one end of flow path 23F. The other end of flow path 23E is connected to a connection port of valve 42. One end of flow path 23F is connected to one end of flow path 23D and one end of flow path 23E. The other end of flow path 23F is connected to a connection port of valve 41. Flow paths 23D, 23E, and 23F may be formed of tubular members such as resin tubes or metal or glass piping. The supply unit 54 is attached to the flow path 23A. The arrow shown on the supply unit 54 indicates the direction in which the supply unit 54 sends gas. The supply unit 54 may be configured with a piezo pump or the like.

[0112] 14, the control unit 64 connects the flow path 23B and the inlet 30a of the first chamber 30 using the valve 40, and further controls the supply unit 54 to supply the purge gas from the suction hole 21 shown in FIG. 2 to the first chamber 30. The control unit 64 also connects the flow path 23F and the inlet 32a of the second chamber 32 using the valve 41, and further controls the supply unit 54 to supply the purge gas from the suction hole 21 shown in FIG. 2 to the second chamber 32. The control unit 64 also connects the flow path 23E and the inlet 33a of the third chamber 33 using the valve 42, and further controls the supply unit 54 to supply the purge gas from the suction hole 21 shown in FIG. 2 to the third chamber 33.

[0113] Gas detection system 1C as shown in FIG. 15 includes flow paths 23D, 23E, and 23F, similar to the configuration shown in FIG. 14. Gas detection system 1 includes flow path 27. Gas detection system 1C includes supply unit 55 as a supply unit. One end of flow path 27 is connected to the connection port of valve 40. The other end of flow path 27 is connected to inlet 30a of first chamber 30. Flow path 27 may be composed of a tubular member such as a resin tube or metal or glass piping. Supply unit 55 is attached to flow path 27. An arrow shown on supply unit 55 indicates the direction in which supply unit 55 sends gas. Supply unit 55 may be composed of a piezo pump, a motor pump, or the like.

[0114] Gas detection system 1D as shown in FIG. 16 includes flow path 26, similar to the configuration shown in FIG. 13. Gas detection system 1D includes supply units 56A, 56B, and 56C as supply units. Supply unit 56A is attached to flow path 25A. Supply unit 56B is attached to flow path 25B. Supply unit 56C is attached to flow path 25C. Arrows shown on each of supply units 56A to 56C indicate the direction in which each of supply units 56A to 56C sends gas. Each of supply units 56A to 56C may be configured as a piezoelectric pump, a motor pump, or the like.

[0115] 16, the control unit 64 connects the suction hole 20 and the inlet 30a of the first chamber 30 with the valve 40, and connects the outlet 30b of the first chamber 30 and the flow path 25A with the valve 41. Furthermore, the control unit 64 controls the supply unit 56A to supply the sample gas from the suction hole 20 to the first chamber 30.

[0116] In the configuration shown in FIG. 16 , the control unit 64 connects the suction hole 20 and the inlet 30a of the first chamber 30 using the valve 40, and connects the outlet 30b of the first chamber 30 and the inlet 32a of the second chamber 32 using the valve 41. Furthermore, the control unit 64 connects the outlet 32b of the second chamber 32 and the flow path 25B using the valve 42. Additionally, the control unit 64 controls the supply unit 56B to supply purge gas from the suction hole 21 shown in FIG. 2 to the first chamber 30 via the flow path 23B. The purge gas supplied to the first chamber 30 pushes the sample gas in the first chamber 30 into the second chamber 32. With this configuration, the sample gas in the first chamber 30 is supplied to the second chamber 32.

[0117] In the configuration shown in FIG. 16 , the control unit 64 connects the flow path 23C to the inlet 32a of the second chamber 32 using the valve 41, and connects the outlet 32b of the second chamber 32 to the inlet 33a of the third chamber 33 using the valve 42. Furthermore, the control unit 64 connects the outlet 33b of the third chamber 33 to the flow path 25C using the valve 43. Additionally, the control unit 64 controls the supply unit 56C to supply purge gas from the suction hole 21 shown in FIG. 2 to the second chamber 32 via the flow path 23C. The purge gas supplied from the flow path 23C to the second chamber 32 pushes the sample gas in the second chamber 32 into the third chamber 33. With this configuration, the sample gas in the second chamber 32 is supplied to the third chamber 33 and then to the sensor unit 34.

[0118] 16, the control unit 64 connects the flow path 26 to the inlet 33a of the third chamber 33 using the valve 42, and connects the outlet 33b of the third chamber 33 to the flow path 25C using the valve 43. Furthermore, the control unit 64 controls the supply unit 56C to supply the purge gas from the suction hole 21 as shown in FIG. 2 to the third chamber 33 via the flow path 26.

[0119] A gas detection system 1E as shown in FIG. 17 includes a flow path 26, similar to the configuration shown in FIG. 13. The gas detection system 1E includes flow paths 28, 29A, 29B, and 29C instead of flow paths 25A, 25B, 25C, 25E, and 25F as shown in FIG. 2. The gas detection system 1E includes a supply unit 57 as a supply unit. One end of flow path 28 is connected to a connection port of valve 43. The other end of flow path 28 is connected to a discharge path 22. One end of flow path 29A is connected to a connection port of valve 41. The other end of flow path 29A is connected to one end of flow path 29B and one end of flow path 29C. One end of flow path 29B is connected to a connection port of valve 42. The other end of flow path 29B is connected to one end of flow path 29A and one end of flow path 29C. One end of flow path 29C is connected to one end of flow path 28 and discharge path 22. The other end of flow path 29C is connected to one end of flow path 29A and one end of flow path 29B. Flow paths 28, 29A to 29C may be configured with tubular members such as resin tubes or metal or glass piping. Supply unit 57 is attached to discharge path 22. An arrow shown on supply unit 57 indicates the direction in which supply unit 57 sends gas. Supply unit 57 may be configured with a piezo pump, a motor pump, or the like.

[0120] For example, in the above-described embodiment, the gas detection system 1 is described as being a single device, as shown in FIG. 4. However, the gas detection system of the present disclosure is not limited to a single device. The gas detection system of the present disclosure may include multiple independent devices. The gas detection system of the present disclosure may have a configuration as shown in FIG. 18, for example.

[0121] A gas detection system 1F as shown in FIG. 18 includes a gas detection apparatus 4 and a server apparatus 5. The gas detection apparatus 4 and the server apparatus 5 can communicate with each other via a network 6. A portion of the network 6 may be wired or wireless. The configuration of the gas detection apparatus 4 is similar to the configuration of the gas detection system 1 as shown in FIG. 2. The server apparatus 5 includes a storage unit 5A, a communication unit 5B, and a control unit 5C. The control unit 5C is capable of executing the processing of the control unit 64 as shown in FIG. 4 described above. For example, the control unit 5C is capable of controlling the flow rates of the sample gas and purge gas supplied to the sensor unit 34 as shown in FIG. 2 described above. When supplying the sample gas to the sensor unit 34, the control unit 5C controls the flow rate of the sample gas so that, after a first time has elapsed since the start of supplying the sample gas to the sensor unit 34, the flow rate of the sample gas becomes smaller than the flow rate at the start of supplying the sample gas. Alternatively, the control unit 5C stops the supply of the sample gas to the sensor unit 34 after the first time has elapsed. Furthermore, for example, when supplying purge gas to the sensor unit 34, the control unit 5C controls the flow rate of the purge gas so that the flow rate is equal to or lower than the flow rate at the start of supplying the purge gas after a second time has elapsed since the start of supplying the purge gas to the sensor unit 34. Alternatively, the control unit 5C stops supplying the purge gas to the sensor unit 34 after the above-mentioned second time has elapsed.

[0122] In this disclosure, descriptions such as "first" and "second" are identifiers for distinguishing the configuration. In this disclosure, the configurations distinguished by descriptions such as "first" and "second" can have their numbers interchanged. For example, the first terminal can have its identifiers "first" and "second" interchanged with the second terminal. The identifiers are interchanged simultaneously. The configurations remain distinguished even after the identifiers are interchanged. Identifiers may be deleted. A configuration from which an identifier has been deleted is distinguished by a symbol. The identifiers "first" and "second" in this disclosure should not be used solely to interpret the order of the configurations or to justify the existence of an identifier with a smaller number. [Explanation of symbols]

[0123] 1, 1A~1F Gas Detection System 2 toilets 2A Toilet Bowl 2B toilet seat 3 Electronic equipment 3A display section 4 Gas detection equipment 5. Server equipment 5A storage section 5B Communications Department 5C Control Unit 6 Network 10. Cabinet 20,21 Suction hole 20A, 21A blower 22 Exhaust channel 23A~23F, 24A~24D, 25A~25F, 26~28, 29A, 29B Flow path 30 First Chamber 31 Adsorbents 32,132 Second Chamber 33 Third Chamber 34 Sensor section 35 Fourth Chamber 36 Adsorbents 37 5th Chamber 30a,32a,33a,35a,37a,132a Entrance 30b,32b,33b,35b,37b,132b Exit 40~45 valves 50~52,53A~53C,54,55,56A~56C,57 Supply section 60 Circuit Board 61 Storage section 62 Communications Department 63 Sensor section 64 Control Unit

Claims

1. a first sensor unit that outputs a voltage corresponding to the concentration of the specific gas; a control unit capable of controlling the flow rates of the sample gas and the purge gas supplied to the first sensor unit, when the control unit supplies the sample gas to the first sensor unit, the control unit stops the supply of the sample gas to the first sensor unit after a first time has elapsed since the supply of the sample gas to the first sensor unit started, The control unit stores the sample gas in a chamber and supplies the sample gas stored in the chamber to the first sensor unit.

2. A first sensor unit that outputs a voltage corresponding to the concentration of a specific gas; a control unit capable of controlling the flow rates of the sample gas and the purge gas supplied to the first sensor unit, when the control unit supplies the sample gas to the first sensor unit, the control unit stops the supply of the sample gas to the first sensor unit after a first time has elapsed since the supply of the sample gas to the first sensor unit started, A gas detection system in which, after the first time has elapsed, the control unit alternately repeats control to stop the supply of the sample gas to the first sensor unit and control to make the flow rate of the sample gas smaller than the flow rate when the supply of the sample gas began.

3. 10. The gas detection system of claim 1, a second sensor unit capable of detecting that the subject has sat on the toilet seat; The control unit stores the sample gas in the chamber after a predetermined time has elapsed since the second sensor unit detected that the subject has sat on the toilet seat.

4. 4. A gas detection system according to claim 1, further comprising: The control unit controls the flow rate of the purge gas to be equal to or lower than the flow rate at the start of supplying the purge gas to the first sensor unit after a second time has elapsed since the start of supplying the purge gas to the first sensor unit.

5. 4. A gas detection system according to claim 1, further comprising: A gas detection system in which, when supplying the purge gas to the first sensor unit, the control unit stops supplying the purge gas to the first sensor unit after a second time has elapsed since the supply of the purge gas to the first sensor unit began.

6. 6. The gas detection system according to claim 4 or 5, The control unit alternately supplies the sample gas and the purge gas to the first sensor unit.

7. 7. A gas detection system according to any one of claims 1 to 6, The control unit controls the flow rate of the purge gas supplied to the first sensor unit so that the flow rate is greater than the flow rate of the sample gas supplied to the first sensor unit.

8. 8. A gas detection system according to any one of claims 1 to 7, The control unit starts supplying purge gas to the first sensor unit after a third time period that is longer than the first time period has elapsed.

9. A gas detection system according to claim 1 or any one of claims 3 to 8 dependent on claim 1, A gas detection system in which, after the first time has elapsed, the control unit alternately repeats control to stop the supply of the sample gas to the first sensor unit and control to make the flow rate of the sample gas smaller than the flow rate when the supply of the sample gas began.

10. a first sensor unit that outputs a voltage corresponding to the concentration of the specific gas; a control unit capable of controlling the flow rates of the sample gas and the purge gas supplied to the first sensor unit, A gas detection device in which, when supplying the sample gas to the first sensor unit, the control unit stops supplying the sample gas to the first sensor unit after a first time has elapsed since the supply of the sample gas to the first sensor unit began.

11. a toilet having a toilet bowl; a suction hole for sucking the sample gas from inside the toilet bowl; 11. The gas detection device according to claim 10, wherein the sample gas sucked through the suction hole is supplied to the first sensor portion.

12. supplying the sample gas to a first sensor unit that outputs a voltage corresponding to the concentration of the specific gas; A gas detection method for detecting a type and concentration of a gas contained in a sample gas based on an output of the first sensor unit, When the sample gas is supplied to the first sensor unit, the supply of the sample gas to the first sensor unit is stopped after a first time has elapsed since the supply of the sample gas to the first sensor unit was started; The gas detection method includes storing the sample gas in a chamber, and supplying the sample gas stored in the chamber to the first sensor unit.

13. A sample gas is supplied to a first sensor unit that outputs a voltage corresponding to the concentration of a specific gas; A gas detection method for detecting a type and concentration of a gas contained in a sample gas based on an output of the first sensor unit, When the sample gas is supplied to the first sensor unit, the supply of the sample gas to the first sensor unit is stopped after a first time has elapsed since the supply of the sample gas to the first sensor unit was started; A gas detection method that alternately repeats, after the first time has elapsed, control to stop the supply of the sample gas to the first sensor unit and control to make the flow rate of the sample gas smaller than the flow rate at the start of the supply of the sample gas.

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