CN220530012U

CN220530012U - Expiration flow control device, expiration collector and expiration NO detection device

Info

Publication number: CN220530012U
Application number: CN202321706962.XU
Authority: CN
Inventors: 李元江
Original assignee: Shenzhen Meimeimeichuangyi Medical Technology Co ltd
Current assignee: Shenzhen Meimeimeichuangyi Medical Technology Co ltd
Priority date: 2023-06-30
Filing date: 2023-06-30
Publication date: 2024-02-27
Anticipated expiration: 2033-06-30

Abstract

The utility model relates to the technical field of exhaled air NO detection, in particular to an exhaled air flow control device, an exhaled air collector and an exhaled air NO detection device, wherein the exhaled air flow control device comprises: the device comprises a controller, a throttle valve, a motor and a flow sensor; the throttle valve and the flow sensor are connected in series and communicated with a main gas path, and one end of the main gas path is an exhalation port; the throttle valve is in transmission connection with the motor, and the controller is electrically connected with the motor and the flow sensor; the controller is used for controlling the running state of the motor through the detection data of the flow sensor, and the throttle valve is driven to change the airflow flow area of the main air channel when the motor runs. Compared with the prior art, the respiratory flow maintaining device provided by the utility model can solve the technical problem of inaccurate detection result caused by unstable expiratory flow when detecting expiratory gas NO.

Description

Expiration flow control device, expiration collector and expiration NO detection device

Technical Field

The utility model relates to the technical field of exhaled air NO detection, in particular to an exhaled air flow control device, an exhaled air collector and an exhaled air NO detection device.

Background

In clinical detection of medicine, nitric oxide (fractional exhaled nitric oxide, feno) detection of exhaled breath is becoming more and more popular, NO in exhaled breath of a human body is mainly generated on respiratory tract, and when the airway is inflamed, the concentration of NO in exhaled breath is increased, so that exhaled breath NO is used as a biomarker of airway inflammation, and the determination of exhaled breath NO is widely applied to diagnosis and monitoring of respiratory tract diseases at present.

However, the concentration of NO in the exhaled air is a flow dependent indicator, and when different exhalation flows are used, the detected concentration of NO characterizes the inflammation of different respiratory sites. For example, feNO ₅₀ And FeNO ₂₀₀ An indicator of the concentration of NO in exhaled air detected at 50 ml/s.+ -. 10% and 200 ml/s.+ -. 10% of exhaled air flow, respectively, wherein FeNO ₅₀ Reflecting the condition of large airway inflammation mainly of bronchus, feNO ₂₀₀ Also known as alveolar nitric oxide (concentration of alveolar nitric oxide, caNO) or small airway nitric oxide, which is an indicator of small airway inflammation that characterizes the peripheral airways and/or alveolar regions. In addition, there is also often nasal exhalation nitric oxide (nasal exhalation nitric oxide, fnNO), which primarily reacts to upper airway inflammatory conditions, as well as severely limiting the flow of exhaled air.

Therefore, the expiratory flow can affect the detection result of the medical detection item, which means that ensuring the stability of the expiratory flow of the subject is a technical problem to be solved in order to realize the accuracy of the measurement result when NO detection is performed.

Disclosure of Invention

The method aims to solve the technical problem that the detection result is inaccurate due to unstable expiratory flow when the expiratory NO is detected at present.

To solve the above-mentioned technical problem, a first aspect of the present utility model provides an expiratory flow control device, including:

the device comprises a controller, a throttle valve, a motor and a flow sensor;

the throttle valve and the flow sensor are connected in series and communicated with a main gas path, and one end of the main gas path is an exhalation port;

the throttle valve is in transmission connection with the motor, and the controller is electrically connected with the motor and the flow sensor;

the controller is used for controlling the running state of the motor through the detection data of the flow sensor, and the throttle valve is driven to change the airflow flow area of the main air channel when the motor runs.

In some possible implementations, the exhalation port and the flow sensor are located at opposite ends of the throttle valve, respectively.

In some possible implementations, the exhalation port and the throttle valve are located at each end of the flow sensor.

In some possible implementations, the throttle valve includes a valve body, a throttle end, and a transmission rod, where the valve body is a hollow shell and has an air inlet and an air outlet, the throttle end is connected with the motor through the transmission rod, and when the motor operates, the transmission rod drives the throttle end to change the air flow area at the air inlet.

In some possible implementations, the throttle end is a conical end, the transmission rod is a telescopic rod, the motor is a linear stepping motor, the conical end is opposite to the air inlet and is in transmission connection with a rotating shaft of the linear stepping motor through the telescopic rod, and when the linear stepping motor operates, the conical end is driven to do linear motion and plug or open the air inlet.

In some possible implementations, the expiratory flow control device further comprises:

the first limit switch and the second limit switch are electrically connected with the controller, the first limit switch and the second limit switch are both positioned in the movement stroke of the throttling end or the transmission rod, and when the first limit switch or the second limit switch is triggered, the controller controls the motor to stop running.

In some possible implementations, the first limit switch and the second limit switch are both optoelectronic switches.

In some possible implementations, the hole wall of the air inlet is provided with an elastic gasket.

In order to solve the above technical problem, a second aspect of the present utility model further provides an exhalation collector, including:

the plenum and the exhalation flow control device of any one of the first aspect and the possible implementation manners of the first aspect, the exhalation flow control device is in communication with the plenum through a gas path.

To solve the above technical problem, a third aspect of the present utility model further provides an exhaled breath NO detection device, including:

the NO detection assembly and the exhalation flow control device according to any one of the first aspect and the possible implementation manners of the first aspect are in communication with each other via a gas path.

Compared with the prior art, the expiratory flow control device provided by the embodiment of the utility model has the following advantages:

the expiration flow control device comprises a controller, a throttle valve, a motor and a flow sensor, wherein the throttle valve and the flow sensor are connected in series and communicated on a main gas path, one end of the main gas path is an expiration port, and the other end of the main gas path is an exhaust port. The throttle valve is connected with the motor in a transmission way, the controller is electrically connected with the motor and the flow sensor, and the controller can control the running state of the motor through detection data of the flow sensor. The motor can drive the throttle valve to change the airflow flow area of the main air channel during operation, so that the airflow flow in the main air channel is changed, the expiratory flow of a subject is stable, and the accuracy of the expiratory NO detection result is improved.

Drawings

In order to more clearly illustrate the technical solutions of embodiments or conventional techniques of the present application, the drawings required for the descriptions of the embodiments or conventional techniques will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present application, and other drawings may be obtained according to these drawings without inventive effort for a person of ordinary skill in the art.

FIG. 1 is a schematic representation of one embodiment of an expiratory flow control device 100 provided by the present utility model;

FIG. 2 is a schematic illustration of another embodiment of an expiratory flow control device 100 provided by the present utility model;

FIG. 3 is a schematic illustration of another embodiment of an expiratory flow control device 100 provided by the present utility model;

FIG. 4 is a schematic illustration of another embodiment of an expiratory flow control device 100 provided by the present utility model;

FIG. 5 is a schematic diagram of one embodiment of an exhalation collector 200 provided by the present utility model;

fig. 6 is a schematic view of an embodiment of an exhaled NO detection device 300 provided by the present utility model.

The attached drawings are used for identifying and describing:

100. an expiratory flow control device;

110. a controller; 120. a throttle valve; 130. a motor; 140. a flow sensor; 121. a valve body; 122. a throttle end; 123. a transmission rod; 1221. a tapered end; 1231. a telescopic rod; 1301. a linear stepper motor; a. a baffle; b, a first photoelectric switch; c, a second photoelectric switch;

200. an exhalation collector; 210. a plenum chamber;

300. exhaled breath NO detection means; 310. NO detection component.

Description of the embodiments

In order to facilitate an understanding of the present application, a more complete description of the present application will now be provided with reference to the relevant figures. Examples of the present application are given in the accompanying drawings. This application may, however, be embodied in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

It will be understood that the terms "first," "second," and the like, as used herein, may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another element. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," and/or the like, specify the presence of stated features, integers, steps, operations, elements, components, or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or groups thereof.

It will be understood that when an element is referred to as being "fixed to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and the like are used herein for illustrative purposes only.

In the present utility model, the terms "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "lateral", "longitudinal" and the like indicate an azimuth or a positional relationship based on that shown in the drawings. These terms are only used to better describe the present utility model and its embodiments and are not intended to limit the scope of the indicated devices, elements or components to the particular orientations or to configure and operate in the particular orientations. Also, some of the terms described above may be used to indicate other meanings in addition to orientation or positional relationships, for example, the term "upper" may also be used to indicate some sort of attachment or connection in some cases. The specific meaning of these terms in the present utility model will be understood by those of ordinary skill in the art according to the specific circumstances.

Furthermore, the terms "mounted," "configured," "provided," "connected," and "connected" are to be construed broadly. For example, it may be a fixed connection, a removable connection, or a unitary construction; may be a mechanical connection, or an electrical connection; may be directly connected, or indirectly connected through intervening media, or may be in internal communication between two devices, elements, or components. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances.

To solve the above-mentioned problems, the present utility model provides an expiratory flow control device 100, referring to fig. 1-4, the expiratory flow control device 100 includes:

a controller 110, a throttle valve 120, a motor 130, and a flow sensor 140;

the throttle valve 120 and the flow sensor 140 are connected in series and communicated on a main air path, and one end of the main air path is an exhalation port;

the throttle valve 120 is in transmission connection with the motor 130, and the controller 110 is electrically connected with the motor 130 and the flow sensor 140;

the controller 110 is configured to control an operation state of the motor 130 according to detection data of the flow sensor 140, and when the motor 130 is operated, the throttle valve 120 is driven to change an airflow area of the main air path.

In this embodiment, the controller 110 may be connected to the motor 130 via a motor drive circuit and have a communication connection with the flow sensor 140, and the flow sensor 140 may be a differential pressure type flow sensor. Upon detection of a subject, the controller 110 may control the motor 130 based on data detected by the flow sensor 140. The controller 110 may employ a micro control unit (microcontroller unit, MCU), a field programmable gate array (field programmable gate array, FPGA) chip, or other control chip, and is not limited herein.

The throttle valve 120 and the flow sensor 140 are located on the same main air path, the main air path is an air vent air path formed by the throttle valve 120, the flow sensor 140 and connecting pipes therebetween, air flow exhaled by a user from an exhalation port can respectively pass through the throttle valve 120 and the flow sensor 140, and cross sectional areas of the main air path at different positions can be different. The throttle valve 120 is in driving connection with the motor 130 and is disposed in the main air path, the throttle valve 120 can change the cross-sectional area of the main air path at the throttle valve 120, or referred to as the air flow area, and the flow sensor 140 can detect the air flow in the main air path.

Specifically, prior to the subject's detection, a target flow rate may be set for the controller 110 by a host computer or other input device connected to the controller 110. During the test, the controller 110 may continuously acquire the flow data detected by the flow sensor 140 at a set time interval, further determine a difference or a ratio between the flow data and the target flow, and calculate the control parameter of the output motor 130 by using a set control algorithm according to the difference or the ratio. The controller 110 may then send a control command including the control parameter to the motor 130, where the control parameter may include one or more parameters such as a steering direction, a rotation duration, a pulse number, or a rotation position of a rotor of the motor 130 according to a type of the motor 130.

Because the motor 130 is in transmission connection with the throttle valve 120, when the motor 130 operates, the throttle valve 120 can be driven to operate, the airflow flow area of the main air channel is changed, and the blockage or dredging of the airflow is realized, so that the airflow flow in the main air channel is changed. The drive connection may take the form of a gear, a coupling or a worm, among others. It may be set that the controller 110 controls the gas flow in the main gas path through controlling the motor 130, so that the gas flow tends to a set target flow, and the stability of the flow of the exhaled gas in the detection process is maintained.

It should be noted that, in this embodiment, the control algorithm may adopt PID (proportion integral differential) algorithm or other similar algorithms, and may form closed-loop adjustment of the opening of the flow-throttling valve 120, and continuously adjust the opening of the valve according to the detected flow, so that the expiratory flow reaches the target flow, which is not described in detail herein.

Compared with the prior art, the expiratory flow control device 100 provided by the embodiment of the utility model has the following advantages:

the expiratory flow control device 100 comprises a controller 110, a throttle valve 120, a motor 130 and a flow sensor 140, wherein the throttle valve 120 and the flow sensor 140 are connected in series and communicated on a main gas path, one end of the main gas path is an expiratory port, and the other end of the main gas path is an exhaust port. The throttle valve 120 is in transmission connection with the motor 130, the controller 110 is electrically connected with the motor 130 and the flow sensor 140, and the controller 110 can control the operation state of the motor 130 through the detection data of the flow sensor 140. When the motor 130 operates, the throttle valve 120 can be driven to change the airflow area of the main air channel, so as to change the airflow flow in the main air channel, thereby stabilizing the expiratory flow of the subject and improving the accuracy of the expiratory NO detection result.

In some possible implementations, the exhalation port and the flow sensor 140 are located at each end of the throttle valve 120.

In this embodiment, the two ends of the throttle valve 120 are an air inlet and an air outlet, the air outlet is connected to the air inlet in a conductive manner, the flow sensor 140 is connected to the air outlet in a conductive manner, and the apertures of the air inlet and the air outlet may be the same or different.

In some possible implementations, the exhalation port and the throttle valve 120 are located at each end of the flow sensor 140.

In this embodiment, the flow sensor 140 may be a flow sensor, one end of which is an input port, and the other end of which is an output port, the breathing port may be connected to the input port of the flow sensor 140 in a conductive manner, and the throttle valve 120 is connected to the output port of the flow sensor 140 in a conductive manner.

In some possible implementations, the throttle valve 120 includes a valve body 121, a throttle end 122, and a transmission rod 123, where the valve body 121 is a hollow shell and has an air inlet and an air outlet, the throttle end 122 is connected to the motor 130 through the transmission rod 123, and when the motor 130 is operated, the transmission rod 123 drives the throttle end 122 to change the airflow area at the air inlet.

In this embodiment, taking fig. 3 as an example, the throttle valve 120 shown in fig. 1 or fig. 2 may be a hollow air guiding valve structure as a whole, and may include a valve body 121 and a valve core, where the valve core specifically includes a throttle end 122 and a transmission rod 123, and the valve body 121 is a hollow housing structure, and has an air inlet and an air outlet, and the throttle end 122 is located between the air inlet and the air outlet. One end of the driving rod 123 is connected with the motor 130, the other end is connected with the throttle end 122, after the motor 130 operates, the driving rod 123 can drive the throttle end 122 to move, the air inlet is blocked or opened, and the air flow area at the air inlet is changed, so that the air flow in the whole main air path is changed. The cross-sectional area of the throttling end 122 needs to be larger than that of the air inlet, and the throttling end 122 and the driving rod 123 can be of various structures, such as a sheet structure, which is tightly attached to the inner wall of the air inlet and can rotate by attaching to the inner wall, so that the motor 130 can shield or open the air inlet after driving the throttling end 122 to rotate by the driving rod 123.

In some possible implementations, the throttle end 122 is a conical end 1221, the transmission rod 123 is a telescopic rod 1231, the motor 130 is a linear stepping motor 1301, the conical end 1221 is opposite to the air inlet and is in transmission connection with a rotation shaft of the linear stepping motor 1301 through the telescopic rod 1231, and when the linear stepping motor 1301 operates, the conical end 1221 is driven to perform linear motion and blocks or opens the air inlet.

In this embodiment, further to the example of fig. 4, the throttle end 122 shown in fig. 3 may be a tapered end 1221, the transmission rod 123 may be a telescopic rod 1231, and the motor 130 may be a linear stepping motor 1301. The head end of the conical end 1221 is opposite to the air inlet, the tail end is in transmission connection with the linear stepping motor 1301 through a telescopic rod 1231, and after the linear stepping motor 1301 operates, the conical end 1221 can be driven by the telescopic rod 1231 to do front-back linear movement, so that the air inlet is blocked or opened.

Specifically, a directional control signal line and a driving signal line may be connected between the controller 110 and the linear stepper motor 1301, and the controller 110 may calculate the number of steps and the movement direction of the linear stepper motor 1301 required to move according to the collected flow data and the target flow meter by using an incremental PID algorithm, so as to control the number of steps corresponding to the movement of the linear stepper motor 1301, thereby realizing the adjustment of the opening of the throttle valve 120. In addition, the controller 110 further includes a timer function, which can use a pulse width modulation (pulse width modulation, PWM) output function of the timer and a count overflow interrupt function, and after the timer function is started, a PWM signal can be automatically output to the driving signal line, and after each period is finished, the linear stepping motor 1301 moves one step, and the main control automatically enters the overflow interrupt program. The PID algorithm and the main control timer function are combined, the PID algorithm calculates the number of moving steps, and the timer automatically outputs PWM signals until the number of moving steps is reduced to 0. The PWM signal output by the timer is used, and the period is constant, and the time interval is the same every time the linear stepping motor 1301 is driven, so that the movement is stable and quick.

In some possible implementations, the expiratory flow control device 100 further comprises:

the first limit switch and the second limit switch are electrically connected with the controller 110, the first limit switch and the second limit switch are both located in the movement stroke of the throttle end 122 or the transmission rod 123, and when the first limit switch or the second limit switch is triggered, the controller 110 controls the motor 130 to stop running.

In this embodiment, the expiratory flow control device 100 further includes a first limit switch and a second limit switch, and the first limit switch and the second limit switch may be electrically connected to the controller 110 through a signal line. The first limit switch and the second limit switch are both located in the movement stroke of the throttle end 122 or in the movement stroke of the transmission rod 123. When either limit switch is triggered, the motor 130 is stopped. The first limit switch and the second limit switch may be respectively located at maximum travel positions in two opposite directions on the movement travel, so as to avoid the situation that the throttle end 122 or the transmission rod 123 is driven by the motor 130 to prop against the inner wall of the valve body 121, resulting in the locked rotation of the motor 130.

In this embodiment, the first limit switch and the second limit switch are all photoelectric switches, and the two photoelectric switches are all electrically connected with the controller 110.

Specifically, taking fig. 4 as an example, the first limit switch is a first photoelectric switch b, the second limit switch is a second photoelectric switch c, and the first limit switch and the second limit switch are respectively located on the inner wall of the upper top wall of the valve body 121, and the telescopic rod 1231 may be provided with a blocking piece a. When the blocking piece a on the telescopic rod 1231 moves to the position below any photoelectric switch, the blocking piece a can block the infrared rays of the photoelectric switch, and the controller 110 can obtain a signal. The two photoelectric switches are used as two positioning positions in the device, namely a maximum adjustment position of the throttle valve 120 and a minimum adjustment position of the throttle valve 120. The maximum adjustment position is on the right, and when the linear stepping motor 1301 is contracted to move rightward, the shutter a moves to the maximum adjustment position, indicating that the movement to the right is no longer possible, and the controller 110 stops the driving signal output and does not move to the right any more. The minimum adjustment position is on the left, and when the stepping motor 130 is moved to the left, the shutter a is moved to the minimum adjustment position, indicating that the movement to the left is no longer possible, and the controller 110 stops the driving signal output and no longer allows the movement to the left. In this way, the situation that the linear stepping motor 1301 is blocked and rotated due to the fact that the linear stepping motor 1301 drives the telescopic rod 1231 to excessively shrink or the telescopic rod 1231 excessively stretches out of the conical end 1221 rightward to prop against the throttle valve 120 can be avoided, and therefore a certain protection function is provided for the linear stepping motor 1301. The two photoelectric switches are matched for use, so that the initial position of the linear stepping motor 1301 does not need to be recorded, and the linear stepping motor 1301 does not need to be reset to the initial position after each expiration.

In this embodiment, in order to avoid mutual wear when the tapered end 1221 is in contact with the air inlet, an elastic washer may be provided at the air inlet to provide some cushioning function.

To solve the above technical problem, the present utility model further provides an exhalation collector 200, specifically referring to fig. 5, the exhalation collector 200 includes:

the plenum 210 and the exhalation flow control device 100 of any one of the figures 1-4 and any one of the possible implementations, the exhalation flow control device 100 being in pneumatic communication with the plenum 210.

In this embodiment, the gas collection chamber 210 may be a device with a gas storage function, such as a gas collection bag, and the gas collection chamber 210 may be connected to the outlet of the above-mentioned expiratory flow control device 100, and after the gas exhaled by the user passes through the expiratory flow control device 100, the gas is stored in the gas collection chamber 210, so as to facilitate offline collection and detection of the exhaled gas NO.

Compared with the prior art, the exhalation collector 200 provided by the embodiment of the utility model has the following advantages:

the breath collector 200 comprises a gas collection chamber 210 and a breath flow control device 100, wherein the breath flow control device 100 comprises a controller 110, a throttle valve 120, a motor 130 and a flow sensor 140, wherein the throttle valve 120 and the flow sensor 140 are connected in series and communicated on a main gas path, one end of the main gas path is a breath port, and the other end is an exhaust port. The throttle valve 120 is in transmission connection with the motor 130, the controller 110 is electrically connected with the motor 130 and the flow sensor 140, and the controller 110 can control the operation state of the motor 130 through the detection data of the flow sensor 140. When the motor 130 operates, the throttle valve 120 can be driven to change the airflow area of the main air channel, so as to change the airflow flow in the main air channel, thereby stabilizing the expiratory flow of the subject and improving the accuracy of the expiratory NO detection result.

To solve the above-mentioned technical problem, the present utility model further provides an exhaled breath NO detection device 300, and specifically referring to fig. 6, the exhaled breath NO detection device 300 includes:

the NO detection assembly 310 and the expiratory flow control device 100 of any one of fig. 1-4 and any one of possible implementation, wherein the NO detection assembly 310 is in communication with the expiratory flow control device 100 through a gas path, and the NO detection assembly 310 includes a NO sensor, so as to detect the exhaled air flowing from the expiratory flow control device 100, and analyze the concentration of NO therein for the purpose of subsequent diagnosis.

Compared with the prior art, the exhaled air NO detection device 300 provided by the embodiment of the utility model has the following advantages:

the expired air NO detection device 300 includes a NO detection assembly 310 and an expired air flow control device 100, the expired air flow control device 100 includes a controller 110, a throttle valve 120, a motor 130 and a flow sensor 140, wherein the throttle valve 120 and the flow sensor 140 are connected in series on a main air path, one end of the main air path is an expired air port, and the other end is an exhaust port. The throttle valve 120 is in transmission connection with the motor 130, the controller 110 is electrically connected with the motor 130 and the flow sensor 140, and the controller 110 can control the operation state of the motor 130 through the detection data of the flow sensor 140. When the motor 130 operates, the throttle valve 120 can be driven to change the airflow area of the main air channel, so as to change the airflow flow in the main air channel, thereby stabilizing the expiratory flow of the subject and improving the accuracy of the expiratory NO detection result.

The technical features of the above embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples merely represent a few embodiments of the present application, which are described in more detail and are not to be construed as limiting the scope of the utility model. It should be noted that it would be apparent to those skilled in the art that various modifications and improvements could be made without departing from the spirit of the present application, which would be within the scope of the present application. Accordingly, the scope of protection of the present application is to be determined by the claims appended hereto.

Claims

1. An exhalation flow control device, comprising:

the device comprises a controller, a throttle valve, a motor and a flow sensor;

2. The expiratory flow control device of claim 1 wherein the expiratory port and the flow sensor are located at respective ends of the throttle valve.

3. The expiratory flow control device of claim 1 wherein the expiratory port and the throttle valve are located at respective ends of the flow sensor.

4. The expiratory flow control device of any one of claims 1-3 wherein the throttle valve comprises a valve body, a throttle tip and a drive rod, the valve body being a hollow housing and having an air inlet and an air outlet, the throttle tip being connected to the motor by the drive rod, the drive rod driving the throttle tip to change the air flow area at the air inlet when the motor is running.

5. The expiratory flow control device of claim 4 wherein the throttle tip is a tapered tip, the drive rod is a telescopic rod, the motor is a linear stepper motor, the tapered tip is opposite to the air inlet and is in drive connection with a rotating shaft of the linear stepper motor through the telescopic rod, and the tapered tip is driven to perform linear motion and block or unblock the air inlet when the linear stepper motor is operated.

6. The expiratory flow control device of claim 4, further comprising:

7. The expiratory flow control device of claim 6 wherein the first limit switch and the second limit switch are both optoelectronic switches.

8. The expiratory flow control device of claim 5 wherein the orifice wall of the air inlet is provided with a resilient gasket.

9. An exhalation collector, comprising:

a plenum and the expiratory flow control device of any one of claims 1 to 8 in communication with the plenum through a gas circuit.

10. An exhaled NO detection device, comprising:

an NO detection assembly and an expiratory flow control device according to any one of claims 1 to 8, the NO detection assembly in communication with the expiratory flow control device via an air circuit.