Breath measurement device
By designing a pipeline structure in the breath measurement equipment with the introduction tube that does not extend to the gas diffusion area and a built-in gas sensor, the problem of lower sensor output and high power consumption in existing equipment is solved, achieving more efficient gas detection and power savings.
Patent Information
- Application Number
- JP2023184523
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2023-10-27
- Publication Date
- 2025-05-13
AI Technical Summary
When used, existing breath measuring equipment is difficult to effectively reflect the components in the breathing air, resulting in the sensor output being lower than necessary and the power consumption is high.
A breath measuring device is designed, and its pipeline structure includes a guide tube that does not extend to the gas diffusion area, and a gas sensor built in the runner section, so that effective gas extraction and power saving can be achieved by controlling the opening and closing of the valve.
Effectively reduces power consumption and prevents sensor output from being lower than necessary, ensuring accurate detection of specific gases in breathing.
Smart Images
Figure 2025073600000001_ABST
Abstract
Description
[Technical field]
[0001] The present invention relates to a breath measuring device. [Background technology]
[0002] Conventionally, there is known a breath measuring device that measures the concentration of a specific gas contained in the breath (see, for example, Patent Document 1). Such a breath measuring device includes an attachment into which a person's breath is blown, a flow path tube that is connected to the attachment and has a larger diameter than the outlet of the attachment and through which the breath passes, an introduction tube whose tip protrudes inside the flow path tube, and a gas sensor (second gas sensor) that is connected to the introduction tube and detects the concentration of the specific gas contained in the breath. In addition, the gas sensor is connected to a solenoid valve, and the breath measuring device is configured to draw the breath in the flow path tube to the gas sensor side by the operation of the solenoid valve. [Prior art documents] [Patent documents]
[0003] [Patent Document 1] Patent No. 6671008 Summary of the Invention [Problem to be solved by the invention]
[0004] In the breath measuring device according to Patent Document 1, the tip of the introduction tube protrudes to a portion of the flow path tube that is an extension region of the outlet of the attachment. However, the present inventors have found that when the tip of the introduction tube protrudes to the extension portion, the following problems arise.
[0005] First, when the breath measurement device draws breath into the gas sensor side by the solenoid valve, the breath measurement device draws in the breath in the flow tube when the solenoid valve is off, from the viewpoint of reducing the amount of power required for the operation of the solenoid valve. Therefore, when the breath measurement device draws in breath during measurement by the gas sensor, first, the solenoid valve is turned on to discharge gas from the introduction tube to the flow tube side, and then the solenoid valve is turned off to draw the breath in the flow tube to the alcohol sensor side. As a result, the breath measurement device only needs to turn on the solenoid valve for a relatively short time, such as momentarily, and then turn it off, and can draw in the breath with only the amount of power required for the relatively short time of on. In other words, if the breath measurement device is configured to draw in breath when the solenoid valve is on, it is necessary to maintain the on state from the start of the measurement of the alcohol concentration until the measurement is completed, which increases the power consumption. However, if the breath measurement device is configured to draw in breath when the solenoid valve is off, the on state can be maintained for a relatively short time, which reduces the power consumption.
[0006] However, in a breath measuring device that is configured to have a relatively short on-state from the viewpoint of power saving, if the tip of the inlet tube is extended to the above-mentioned extension portion, the gas exhaled when the solenoid valve is turned on will be sucked in more when the solenoid valve is turned off afterwards. Therefore, the breath measuring device has a problem that the components of the breath are not easily reflected in the sensor output, and the sensor output becomes lower than necessary even if a specific gas is contained in the breath.
[0007] The present invention has been made to solve such problems, and its purpose is to provide a breath measuring device that reduces power consumption and prevents the sensor output from becoming unnecessarily low when a specific gas is present in the breath. [Means for solving the problem]
[0008] The breath measuring device of the present invention comprises a conduit into which a subject's breath is blown and which has a straight section extending in a straight shape at least on the outlet side, a flow path section which is connected to the conduit and has a large section whose inner diameter is larger at least on the inlet side than the outlet of the conduit and through which the blown breath passes, a gas sensor for measuring the concentration of a specific gas contained in the breath flowing into the flow path section, an introduction tube which introduces the breath in the flow path section to the gas sensor side, and a solenoid valve which performs a drawing operation to draw the breath in the flow path section to the gas sensor side, wherein before performing the drawing operation, the solenoid valve is energized to perform a discharge operation to discharge gas in the introduction tube into the flow path section, and the introduction tube protrudes beyond the inner wall of the large tube through the large tube, to a length such that its tip does not reach within an extension area which extends from the outlet of the conduit along the straight section. Effect of the Invention
[0009] According to the present invention, it is possible to provide a breath measuring device that reduces power consumption and prevents the sensor output from becoming unnecessarily low when a specific gas is contained in the breath. [Brief description of the drawings]
[0010] [Figure 1] 1 is a configuration diagram showing a breath measurement system including a breath measurement device according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a configuration diagram showing details of the breathalyzer shown in FIG. 1. [Diagram 3] 3A and 3B are diagrams showing the operation states of the solenoid valve shown in FIG. 2, in which (a) shows the retracted state and (b) shows the discharged state. [Figure 4] FIG. 3 is a cross-sectional view of the mouthpiece shown in FIG. [Diagram 5] 3A to 3C are diagrams showing the configuration of the flow passage pipe shown in FIG. 2, in which (a) is a side view, (b) is a top view, and (c) is a cross-sectional view of (a). [Figure 6] FIG. 4 is a cross-sectional view showing the connection relationship between a mouthpiece, a flow path tube, and an introduction tube. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0011] The present invention will be described below along with preferred embodiments. Note that the present invention is not limited to the embodiments shown below, and can be modified as appropriate within the scope of the present invention. In addition, in the embodiments shown below, some configurations are omitted from illustration and description, but it goes without saying that publicly known or well-known technologies are appropriately applied to the details of the omitted technologies within the scope of no contradiction with the contents described below.
[0012] Fig. 1 is a configuration diagram showing a breath measurement system including a breath measurement device according to this embodiment. As shown in Fig. 1, the breath measurement system 1 measures the concentration of a specific gas contained in the breath of a subject T. In this embodiment, the breath measurement system 1 measures the alcohol concentration contained in the breath of the subject T to determine whether the subject T is under the influence of alcohol. Such a breath measurement system 1 is configured to include an alcohol detector (breath measurement device) 10 and an imaging terminal 20.
[0013] The breathalyzer 10 has a main functional section for measuring an alcohol concentration, and transmits information on the measured alcohol concentration to the imaging terminal 20. The imaging terminal 20 is configured by a terminal such as a smartphone that has installed therein a program (application) that can operate as a part of the breath measurement system 1. The imaging terminal 20 prevents impersonation of the subject T by capturing an image of a person blowing into the breathalyzer 10.
[0014] Furthermore, the imaging terminal 20 transmits the alcohol concentration information received from the breathalyzer 10 and the captured image information of the subject T obtained by imaging to the external server 30. As a result, the external server 30 stores the alcohol concentration information and the captured image information. The measured alcohol concentration information is displayed on the display unit 10D of the breathalyzer 10 and the display unit 20D of the imaging terminal 20.
[0015] Fig. 2 is a configuration diagram showing the details of the breathalyzer 10 shown in Fig. 1. In Fig. 2, the housing 10b of the breathalyzer 10 is shown by a dashed line so that the internal configuration of the breathalyzer 10 can be seen.
[0016] As shown in Fig. 2, the breathalyzer 10 has a mouthpiece (pipe) MP and a detector main body 10a. The mouthpiece MP is held by the subject T in his / her mouth, and the subject T's breath is blown into it. The subject T may hold the mouthpiece MP in his / her mouth, but from a hygienic point of view, it is preferable that the mouthpiece MP has a detachable cylindrical member such as a straw. In this case, the subject T attaches the cylindrical member to the mouthpiece MP and then blows breath into the cylindrical member.
[0017] The detector body 10a has a flow path pipe (flow path portion) F inside the housing 10b. The flow path pipe F is in communication with the mouthpiece MP when the mouthpiece MP is attached to the detector body 10a. Therefore, the breath blown in by the subject T passes through the flow path pipe F via the mouthpiece MP (and further the cylindrical member).
[0018] The detector main body 10a also includes an alcohol sensor (gas sensor) 11, an introduction tube I, a pressure sensor 12, and a solenoid valve 13. The alcohol sensor 11 is for measuring the alcohol concentration (concentration of a specific gas) contained in the breath passing through the flow path tube F. The alcohol sensor 11 outputs a signal corresponding to the alcohol concentration to a control unit (not shown). The control unit measures the alcohol concentration in the breath based on the signal from the alcohol sensor 11.
[0019] The inlet pipe I is a flow path that guides the breath in the flow path pipe F to the alcohol sensor 11. One end of this inlet pipe I is on the flow path pipe F side, and the other end is branched in two directions. The alcohol sensor 11 is provided between one end of the inlet pipe I and the branching point. One branch of the inlet pipe I is a first flow path I1 connected to the pressure sensor 12, and the other branch is a second flow path I2 connected to the solenoid valve 13.
[0020] The pressure sensor 12 is for detecting the expiratory pressure in the flow path tube F. This pressure sensor 12 also outputs a signal corresponding to the expiratory pressure to a control unit (not shown). The control unit measures the expiratory pressure based on the signal from the pressure sensor 12.
[0021] The solenoid valve 13 performs a drawing operation to draw the breath in the flow passage pipe F to the alcohol sensor 11. Figure 3 is a configuration diagram showing the operating state of the solenoid valve 13 shown in Figure 2, where (a) shows the drawing state and (b) shows the discharge state.
[0022] The solenoid valve 13 is generally composed of a solenoid 13a and a valve 13b. The solenoid 13a is operated by energizing it. The valve 13b moves in the directions of arrows A1 and A2 shown in Figures 3(a) and 3(b) in response to the operation of the solenoid 13a.
[0023] In order to reduce power consumption, the solenoid valve 13 is in the OFF state as shown in Fig. 3(a). That is, the valve 13b of the solenoid valve 13 moves in the direction of the arrow A1. In this state, the solenoid valve 13 is in a drawing-in state in which the exhaled air is drawn in from the flow path pipe F.
[0024] In this embodiment, the solenoid valve 13 is in a retracted state when it is off, so when retracting the exhaled air in the flow path pipe F, it first operates as shown in Fig. 3(b). That is, before performing the retraction operation, the solenoid valve 13 is energized to perform a discharge operation in which the gas in the introduction pipe I is discharged into the flow path pipe F. At this time, the solenoid 13a is energized and in an on state, and the valve 13b moves in the direction of the arrow A2.
[0025] After that, the solenoid 13a is turned off. As a result, the solenoid valve 13 transitions to the retracted state shown in Fig. 3(a), and the breath is drawn from the flow path pipe F to the alcohol sensor 11. In the solenoid valve 13 according to this embodiment, it is only necessary to energize the solenoid 13a when transitioning from the retracted state shown in Fig. 3(a) to the discharge state shown in Fig. 3(b), and the energization time can be short, such as instantaneous.
[0026] Contrary to the solenoid valve 13 according to the present embodiment, when the discharge state shown in FIG. 3(b) is achieved in the off state, the retracted state shown in FIG. 3(a) is achieved by turning on the solenoid valve 13 after being energized. The analysis of the alcohol concentration based on the alcohol sensor 11 is performed by the control unit over a relatively long period of time. If the retracted state is shifted to the discharge state during the analysis of the alcohol concentration, it may not be possible to accurately measure the alcohol concentration. Therefore, contrary to the present embodiment, when the retracted state is achieved by turning on the solenoid valve 13, the retracted state must be maintained during the analysis time, which results in a long on time.
[0027] FIG. 4 is a cross-sectional view of the mouthpiece MP shown in FIG. 2. As shown in FIG. 4, the mouthpiece MP has a generally straight tube structure in which an inlet MP1, which is the side where the exhaled air is blown in, and an outlet MP2, which is the side where the exhaled air is discharged, are connected. This mouthpiece MP has a first inner diameter part MP3 on the inlet MP1 side, and a second inner diameter part MP4 on the outlet MP2 side, which has a smaller diameter than the first inner diameter part MP3. The second inner diameter part MP4 of such a mouthpiece MP is a straight tube part SP that extends in a straight tube shape at least on the outlet MP2 side. The boundary between the first inner diameter part MP3 and the second inner diameter part MP4 forms a step part S, and this step part S forms a saliva stopper.
[0028] The mouthpiece MP also has a protruding portion PR at the second inner diameter portion MP4. This protruding portion PR is an annular portion that protrudes inward from the second inner diameter portion MP4, and the protruding amount is set to a length that is sufficient to press and hold a cylindrical member such as a straw from the outside when the cylindrical member is inserted.
[0029] Furthermore, the mouthpiece MP has a bulge MP5 that protrudes outward. The bulge MP5 is formed with a predetermined length from a position corresponding to the step S, which is the boundary between the first inner diameter portion MP3 and the second inner diameter portion MP4, toward the outlet MP2. This bulge MP5 serves as a grip when attaching or detaching the mouthpiece MP to or from the detector body 10a, for example.
[0030] Fig. 5 is a diagram showing the configuration of the flow path pipe F shown in Fig. 2, where (a) is a side view, (b) is a top view, and (c) is a cross-sectional view of (a). As shown in Fig. 5(a) to (c), the flow path pipe F has a cylindrical shape in which an inlet (inlet) F1, which is an inlet for exhaled air, and an outlet F2, which is an outlet for exhaled air, are connected. As shown in Fig. 5(c), this flow path pipe F has a connection part C on the inlet F1 side into which the outlet MP2 side of the mouthpiece MP fits.
[0031] As shown in Fig. 5(a) and Fig. 5(b), the flow tube F is configured to narrow both above and below and to the side on the discharge port F2 side, so that the flow channel cross-sectional area is reduced at that portion. In detail, as shown in Fig. 5(c), the flow tube F has a large tube section Fa having a predetermined flow channel cross-sectional area, and a small tube section Fb having a flow channel cross-sectional area smaller than that of the large tube section Fa on the discharge port F2 side of the large tube section Fa. Furthermore, the flow tube F has a decrease tube Fc that connects the large tube section Fa and the small tube section Fb and whose flow channel cross-sectional area gradually decreases toward the discharge port F2 side. In the flow tube F, the large tube section Fa is the longest, and the large tube section Fa occupies the majority of the flow tube F. Here, as shown in Fig. 5(c), the discharge port F2 belongs to the small tube section Fb, so that the area is smaller than the cross-sectional area of the large tube section Fa that occupies the majority. It is preferable that this discharge port F2 is an opening smaller than the outlet MP2 of the mouthpiece MP.
[0032] An opening F3 penetrating the side wall of the large tube portion Fa of the flow path tube F is formed. The introduction tube I shown in Fig. 2 is inserted into this opening F3. Fig. 6 is a cross-sectional view showing the connection relationship between the mouthpiece MP, the flow path tube F, and the introduction tube I.
[0033] As described above, the mouthpiece MP is connected to the flow path tube F by fitting the outlet MP2 side into the connecting portion C of the flow path tube F. As is clear from Fig. 6, the large tube portion Fa of the flow path tube F has a larger inner diameter than the outlet MP2 of the mouthpiece MP. In this way, the inner diameter of the large tube portion Fa of the flow path tube F is larger than the outlet MP2, so that the extended area EA shown in Fig. 6 is formed.
[0034] The extension area EA is an area extending from the outlet MP2 of the mouthpiece MP and extending along the straight section SP of the second inner diameter portion MP4. This extension area EA is an area where the flow rate of the exhaled air becomes high when the exhaled air of the subject T is blown into the extension area EA.
[0035] In this embodiment, the introduction pipe I protrudes into the flow path pipe F through the large pipe section Fa. Although the introduction pipe I protrudes beyond the inner wall FW within the large pipe section Fa, the tip Ia of the introduction pipe I is positioned so as not to reach the extension area EA where the flow velocity becomes high.
[0036] 6, the outlet F2 is formed eccentrically toward the introduction pipe I side from the center of the flow path pipe F. When forming an eccentric outlet F2 in this manner, it is preferable to make one side (lower side) of the outlet F2 coincident with the inner wall FW of the flow path pipe F to be flush with it.
[0037] Next, the operation of the breath alcohol detector 10 and the breath measurement system 1 according to this embodiment will be described. First, the subject T inserts a cylindrical member such as a straw from the inlet MP1 of the mouthpiece MP. As a result, the cylindrical member is pressed from the outside by the protrusion PR provided on the second inner diameter portion MP4 and is placed in a held state.
[0038] Next, the subject T turns on the breathalyzer 10 and the imaging terminal 20, and wirelessly connects them. After that, the subject T blows his / her breath into the cylindrical member. As a result, the breath flows from the cylindrical member through the mouthpiece MP to the flow path tube F. At this time, the pressure inside the flow path tube F increases due to the blowing of the breath.
[0039] The control unit judges the increase in pressure based on the signal from the pressure sensor 12, and judges the blowing of breath. When the control unit judges the blowing of breath, it operates the solenoid valve 13 to draw the breath from the flow path pipe F to the alcohol sensor 11 side. At this time, the control unit first performs the discharge operation and then the draw operation as described with reference to FIG. 3.
[0040] Here, for example, the breath detection device according to Patent Document 1 is configured to extend the tip of the introduction tube to the extension region. When the tip of the introduction tube extends to the extension region in this way, even if alcohol is contained in the breath, the sensor output may be lower than necessary. To explain in detail, the solenoid valve is in a retracted state when off from the viewpoint of reducing power consumption. In this case, when the breath is drawn into the alcohol sensor side, the solenoid valve first performs an ejection operation. When the tip of the introduction tube extends to the extension region, the distance from the tip to the opposing wall of the flow path tube is short, and no space is secured. For this reason, the gas exhaled by the solenoid valve being turned on is inhaled in large amounts by the subsequent off. Therefore, even if alcohol is contained in the breath, the sensor output may be lower than necessary.
[0041] In contrast, in the breathalyzer 10 according to this embodiment, the tip Ia of the introduction tube I does not reach the extension area EA. Therefore, the distance from the tip Ia of the introduction tube I to the opposing wall is long, and the gas can be discharged and diffused in a relatively wide space. This makes it difficult to draw in the exhaled gas as it is, and prevents the sensor output from becoming lower than necessary.
[0042] Here, in the breathalyzer 10 according to this embodiment, the introduction tube I branches and is connected to the pressure sensor 12 and the solenoid valve 13. As described above, the flow rate in the extension area EA is faster than outside the extension area EA when breath is blown in, so that the pressure increase can be easily detected by the pressure sensor 12. However, in the breathalyzer 10 according to this embodiment, the tip Ia of the introduction tube I does not reach the extension area EA, and while a decrease in the sensor output can be suppressed, it can easily become difficult to detect the pressure.
[0043] Therefore, in this embodiment, the outlet F2 of the flow path pipe F has a smaller cross-sectional area than the cross-sectional area of the large pipe portion Fa. This makes it difficult for the exhaled air to escape from the outlet F2, which prevents the internal pressure of the flow path pipe F from increasing overall and making it difficult to measure the pressure.
[0044] In addition, since the flow path pipe F has a small pipe section Fb, the internal pressure of the large pipe section Fa located in front of the small pipe section Fb is preferably increased, thereby preventing the pressure from becoming even more difficult to measure.
[0045] With the above configuration, the breathalyzer 10 prevents the sensor output from decreasing more than necessary, and also performs pressure detection appropriately. After (or during) the breathalyzer 10 blows in, the control unit measures the alcohol concentration. The imaging terminal 20 captures an image of the subject T while he or she is blowing in. Information on the measured alcohol concentration and the captured image are transmitted to the external server 30.
[0046] In the breathalyzer 10 according to this embodiment, when the outlet F2 is formed eccentrically from the flow path pipe F, one side of the outlet F2 is made flush with the inner wall FW of the flow path pipe F. This makes it easier for liquids such as saliva and dust to be discharged from the outlet F2 along the inner wall FW.
[0047] In this way, according to the breathalyzer 10 of this embodiment, the solenoid valve 13 is energized before the retraction operation to perform a discharge operation in which the gas in the introduction tube I is discharged into the flow path tube F. Therefore, the time during which the solenoid valve 13 is energized can be limited, and power consumption can be reduced. In addition, the introduction tube I protrudes from the inner wall FW of the flow path tube F by a length such that the tip Ia does not reach the extension area EA. Therefore, the protrusion amount of the introduction tube I is limited, and a space for discharging the gas during the discharge operation before the retraction operation is secured. This prevents the gas from being discharged into a narrow space and remaining there, and the next retraction operation prevents most of the exhaled gas from being inhaled. As a result, the breath of the subject T is appropriately drawn in, and the sensor output is less likely to be lower than necessary when the breath contains alcohol. Therefore, it is possible to provide a breathalyzer 10 that can reduce power consumption and prevent the sensor output from being lower than necessary when the breath contains alcohol.
[0048] The introduction tube I is branched midway and connected to the pressure sensor 12. Here, there is an advantage that it is easier to obtain a high pressure value and measure the pressure when the tip Ia of the introduction tube I reaches the extension area EA. However, in this embodiment, since the tip Ia of the introduction tube I does not reach the extension area EA, it is considered that it becomes difficult to measure the increase in pressure. Therefore, in the breathalyzer 10, the outlet F2 is an opening smaller than the cross-sectional area of the large tube section Fa. This makes it easier to increase the internal pressure of the large tube section Fa when breath is blown in, and can lead to the elimination of the situation in which it becomes difficult to measure the pressure due to the introduction tube I being shortened for the sensor output as described above.
[0049] In addition, since the flow path pipe F has a small pipe section Fb that has a smaller flow path cross-sectional area than the large pipe section Fa on the exhaust outlet F2 side than the large pipe section Fa, the internal pressure of the large pipe section Fa located in front of the small pipe section Fb can be preferably increased, thereby preventing the pressure from becoming even more difficult to measure.
[0050] Although the present invention has been described above based on the embodiments, the present invention is not limited to the above embodiments, and modifications may be made without departing from the spirit of the present invention, and the embodiments may be appropriately combined with each other or with other well-known or publicly known technologies to the extent possible. Furthermore, publicly known or publicly known technologies may be combined to the extent possible.
[0051] For example, the breathalyzer 10 according to the present embodiment is not limited to measuring the alcohol concentration, but may also measure the concentration of other types of gas. Furthermore, in the present embodiment, the breathalyzer 10 itself may have an imaging function. In addition, the breath measurement system 1 is not limited to being composed of two components, the breathalyzer 10 and the imaging terminal 20, but may be composed of three or more components, with each functional unit being mounted on another device, for example.
[0052] In addition, in the breathalyzer 10 according to the present embodiment, the flow path pipe F includes the large pipe section Fa and the small pipe section Fb, but is not limited thereto, and may be a substantially cylindrical shape including only the large pipe section Fa. In this case, the outlet F2 may be made small by, for example, covering a part of the outlet of the large pipe section Fa and leaving the other part open.
[0053] Furthermore, in this embodiment, the inlet pipe I is inserted into the flow path pipe F, and the inlet pipe I and the flow path pipe F are completely separate bodies, but this is not limited to this, and part or all of the inlet pipe I may be formed integrally with the flow path pipe F. [Explanation of symbols]
[0054] 1: Breath measurement system 10: Alcohol detector (breath measuring device) 11: Alcohol sensor (gas sensor) 12: Pressure sensor 13: Solenoid valve EA: Extension area F: Flow path pipe (flow path section) F1: Entrance F2: Outlet Fa: Large canal Fb: Canalicular part FW:Inner wall I: Introduction tube I1: First flow path I2: Second flow path Ia: Tip MP: Mouthpiece (pipe) MP2 :Exit MP4: Second inner diameter section SP: Straight pipe part T: Subject
Claims
1. a conduit into which the breath of the subject is blown and having a straight portion extending straight at least on an outlet side; a flow path portion connected to the pipeline and having a large pipe portion whose inner diameter is larger at least at an inlet side than an outlet side of the pipeline, through which the breath blown in passes; a gas sensor for measuring a concentration of a specific gas contained in the exhaled breath flowing through the flow path; an introduction tube that introduces the exhaled air in the flow path portion to the gas sensor; a solenoid valve that performs a drawing operation to draw the exhaled air in the flow path portion into the gas sensor side, the solenoid valve is energized to perform a discharge operation of discharging the gas in the introduction pipe into the flow path before performing the retraction operation, The introduction pipe protrudes beyond the inner wall of the large pipe portion through the large pipe portion by a length such that the tip of the introduction pipe does not reach within an extension region extending from the outlet of the pipe line along the straight pipe portion. A breath measuring device characterized by:
2. A pressure sensor for detecting an exhalation pressure in the flow path is further provided. the introduction pipe has a first flow path branched midway and connected to the pressure sensor and a second flow path connected to the solenoid valve, The flow path portion has an outlet port which serves as an outlet for exhaled air, The outlet is an opening having an area smaller than the cross-sectional area of the large pipe portion.
2. The breath measuring device according to claim 1 .
3. The flow path portion has a small pipe portion that is located closer to the outlet than the large pipe portion and has a smaller flow path cross-sectional area than the large pipe portion.
3. The breath measuring device according to claim 2 .
Citation Information
Patent Citations
Exhaled breath component measuring device
JP6671008B2