A lung ventilation function measuring device and method based on the principle of sound diffraction

Abstract

The present invention is applicable to the technical field of medical devices, and provides a lung ventilation function measuring device and method based on the principle of sound diffraction. The device includes an air flow pipeline and an orifice plate; an audio input hole and an audio output hole are formed in the pipe wall of the air flow pipeline, the audio input hole is coupled with the audio input port of a mobile phone, and the audio output hole is coupled with the audio output port of the mobile phone; the orifice plate is arranged in the air flow pipeline and is located between the audio input hole and the audio output hole. The orifice plate includes a plurality of sector-shaped thin film pieces, and the plurality of sector-shaped thin film pieces are pivotally arranged in a circumferential arrangement; a section of the air flow pipeline close to the audio output hole is a first ventilation pipeline, and a section of the air flow pipeline close to the audio input hole is a second ventilation pipeline; the present invention can realize the test of lung ventilation function at low cost, is very convenient to use in cooperation with a smart phone, and does not need to be provided with a flow sensor, and does not have the disadvantages of the existing turbine flow sensors.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical devices, and particularly relates to a lung ventilation function measurement device and method based on the principle of sound diffraction. Background Art

[0002] Gas flow sensors are the core components for measuring lung ventilation function. Currently, the common types of gas flow sensors mainly include differential pressure type, hot wire type, ultrasonic type, and eddy current rotation type. They have their own advantages and disadvantages, but all involve electronic and circuit parts, and generally require corresponding human-computer interaction devices, resulting in relatively high hardware costs.

[0003] The existing patent "CN201410714201.8 A Lung Function Sensor Based on a Smart Phone" proposes a breathing flow detection scheme based on a smart phone. However, this scheme is based on the principle similar to that of a turbine flow sensor, inheriting the disadvantage of the turbine flow sensor, that is, the rotor has inertia. When the subject stops blowing, the rotor will still rotate due to inertia, resulting in measurement deviation.

[0004] Based on this, the present invention designs a lung ventilation function measurement device and method based on the principle of sound diffraction to improve the measurement accuracy on the existing basis and solve the problem of measurement deviation described above. Summary of the Invention

[0005] The first objective of the embodiment of the present invention is to provide a lung ventilation function measurement device based on the principle of sound diffraction, which can be used in conjunction with a daily smart phone to achieve lung ventilation function testing at low cost. It is very convenient to use in conjunction with a smart phone, and there is no need to set up a flow sensor, thus avoiding the disadvantages of the existing turbine flow sensors.

[0006] The embodiment of the present invention is implemented as follows. A lung ventilation function measurement device based on the principle of sound diffraction includes an air flow pipeline and an orifice plate.

[0007] The pipe wall of the air flow pipeline is provided with an audio input hole and an audio output hole. The audio input hole is coupled to the audio input port of the mobile phone, and the audio output hole is coupled to the audio output port of the mobile phone.

[0008] The orifice plate is arranged in the air flow pipeline and is located between the audio input hole and the audio output hole. The orifice plate includes a plurality of fan-shaped thin film pieces, and the plurality of fan-shaped thin film pieces are pivotally arranged in a circular arrangement.

[0009] A section of the air flow pipeline close to the audio output hole is a first ventilation pipeline, and a section of the air flow pipeline close to the audio input hole is a second ventilation pipeline.

[0010] Among them, the lung ventilation to be measured pushes the sector film to pivot through the first ventilation pipeline, so that the orifice plate opens. The opened orifice plate allows the lung ventilation to enter the second ventilation pipeline. At the same time, the sound wave output by the mobile phone through the audio output hole propagates towards the audio input hole through the opened orifice plate. The mobile phone acquires the sound wave propagated to the audio input hole, processes it, measures the opening area of the orifice plate and the transmission coefficient of the orifice plate, and then measures the flow rate of the lung ventilation to be measured through relevant physical calculation formulas.

[0011] The second object of the embodiments of the present invention is to provide a method for measuring lung ventilation function based on the principle of sound diffraction, which is used for the device for measuring lung ventilation function based on the principle of sound diffraction as described above. The method includes:

[0012] Set up a mobile phone and an air flow pipeline, so that the audio input hole is coupled with the audio input port of the mobile phone, and the audio output hole is coupled with the audio output port of the mobile phone.

[0013] Output a sound wave from the audio output port of the mobile phone to the audio output hole, acquire the sound wave propagated to the audio input hole, and obtain the sound pressure P0 of the audio input hole.

[0014] Place the orifice plate in the air flow pipeline between the audio input hole and the audio output hole.

[0015] Keep outputting the sound wave to the audio output hole. The lung ventilation to be measured pushes the sector film to pivot through the first ventilation pipeline, so that the orifice plate opens. The opened orifice plate allows the lung ventilation to enter the second ventilation pipeline.

[0016] Then acquire the sound wave propagated to the audio input hole, and obtain the sound pressure P1 of the audio input hole.

[0017] Measure the flow rate of the lung ventilation to be measured through relevant physical calculation formulas.

[0018] The device for measuring lung ventilation function based on the principle of sound diffraction provided by the embodiments of the present invention only includes an air flow pipeline and an orifice plate, and has a relatively simple structure. When used with an ordinary smart phone, based on the principle of sound diffraction, it measures the sound pressure (i.e., P0, P1) at the audio input hole before and after the orifice plate is set, and relevant parameters (such as K3) that can be calibrated in advance, and measures the flow rate of the lung ventilation to be measured. It can realize the test of lung ventilation function at low cost, is very convenient when used with a smart phone, and does not require a flow sensor, avoiding the disadvantages of existing devices using turbine flow sensors. Description of the Drawings

[0019] Figure 1 It is a schematic structural diagram of a device for measuring lung ventilation function based on the principle of sound diffraction provided by the embodiments of the present invention;

[0020] Figure 2 It is the front view of the orifice plate in the embodiments of the present invention;

[0021] Figure 3 It is a test environment diagram of a lung ventilation function measuring device based on the principle of sound diffraction provided by an embodiment of the present invention;

[0022] Figure 4 It is a flowchart of a method for measuring lung ventilation function based on the principle of sound diffraction provided by an embodiment of the present invention.

[0023] In the figure: 10 - air flow pipeline; 11 - audio input hole; 12 - audio output hole; 13 - first ventilation pipeline; 14 - second ventilation pipeline; 20 - orifice plate; 21 - fan-shaped thin film; 30 - mobile phone. Detailed implementation manners

[0024] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0025] It can be understood that the terms "first", "second", etc. used in the present invention can be used herein to describe various elements, but unless otherwise specified, these elements are not limited by these terms. These terms are only used to distinguish the first element from another element.

[0026] In one embodiment, as Figure 1 shown, a lung ventilation function measuring device based on the principle of sound diffraction provided by an embodiment of the present invention includes an air flow pipeline 10 and an orifice plate 20;

[0027] The tube wall of the air flow pipeline 10 is provided with an audio input hole 11 and an audio output hole 12. The audio input hole 11 is coupled to the audio input port of the mobile phone 30, and the audio output hole 12 is coupled to the audio output port of the mobile phone 30, as Figure 3 shown;

[0028] The orifice plate 20 is arranged in the air flow pipeline 10 and is located between the audio input hole 11 and the audio output hole 12. The orifice plate 20 includes a plurality of fan-shaped thin films 21, and the plurality of fan-shaped thin films 21 are pivotally arranged in a circular arrangement, as Figure 2 shown;

[0029] One section of the air flow pipeline 10 close to the audio output hole 12 is the first ventilation pipeline 13, and one section of the air flow pipeline 10 close to the audio input hole 11 is the second ventilation pipeline 14;

[0030] Among them, the lung ventilation to be measured passes through the first ventilation pipeline 13 and then pushes the fan-shaped thin film 21 to pivot, so that the orifice plate 20 opens. The opened orifice plate 20 allows the lung ventilation to enter the second ventilation pipeline 14. At the same time, the sound wave output by the mobile phone 30 through the audio output hole 12 propagates in the direction of the audio input hole 11 through the opened orifice plate 20. The mobile phone 30 acquires the sound wave propagated to the audio input hole 11 and, after processing, measures the opening area of the orifice plate 20 and the transmission coefficient of the orifice plate 20, and then measures the flow rate of the lung ventilation to be measured through relevant physical calculation formulas.

[0031] In this embodiment, the lung ventilation function measuring device based on the sound diffraction principle only includes the air flow pipeline 10 and the orifice plate 20, with a relatively simple structure. When used in combination with a daily smart phone, based on the sound diffraction principle, the sound pressure at the audio input hole 11 before and after the orifice plate 20 is set, and relevant parameters that can be calibrated in advance (such as K3) are measured to measure the flow rate of the lung ventilation to be measured. The lung ventilation function test can be realized at low cost. When used in combination with a smart phone, it is very convenient, and there is no need to set a flow sensor, thus avoiding the disadvantages of the existing turbine flow sensors.

[0032] In an example of this embodiment, the air flow pipeline 10 can be made of a plastic pipe; the plastic pipe can be transparent or opaque, and preferably a transparent plastic pipe.

[0033] In an example of this embodiment, the air flow pipeline 10 can also be made of a glass pipe or a resin pipe.

[0034] In an example of this embodiment, the audio input hole 11 is coupled to the audio input port of the mobile phone 30, and the audio output hole 12 is coupled to the audio output port of the mobile phone 30;

[0035] Generally, the audio input port of the mobile phone 30 is a microphone, and the audio output port of the mobile phone is a speaker. Usually, the microphone and the speaker are both located at the bottom of the mobile phone and on both sides of the charging interface (such as Type-C interface, micro-usb interface, lightning interface);

[0036] For example: the mobile phone 30 is set on the side of the air flow pipeline 10 through a mobile phone holder; and the microphone is docked to the audio input hole 11 of the air flow pipeline 10, and the speaker is docked to the audio output hole 12 of the air flow pipeline 10, that is, the coupling between the audio input hole 11 and the audio input port of the mobile phone 30, and the coupling between the audio output hole 12 and the audio output port of the mobile phone are realized.

[0037] In an example, the orifice plate 20 is arranged in the air flow pipeline 10 and between the audio input hole 11 and the audio output hole 12. Preferably, the orifice plate 20 is arranged on the geometric center line of the audio input hole 11 and the audio output hole 12.

[0038] In one example, the apertures of the audio input hole 11 and the audio output hole 12 are the same; in this way, it is easy to process, reducing the processing cost. At the same time, it is also convenient for the measurement and calculation of sound pressure.

[0039] In one embodiment, a plurality of the sector-shaped thin film pieces 21 are pivotally arranged in a circular arrangement; specifically, it can be 6 pieces, 8 pieces, 9 pieces, 10 pieces, etc.

[0040] A section of the air flow pipeline 10 close to the audio output hole 12 is the first air ventilation pipeline 13, and a section of the air flow pipeline 10 close to the audio input hole 11 is the second air ventilation pipeline 14;

[0041] Among them, the to-be-detected lung ventilation passes through the first air ventilation pipeline 13 and then pushes the sector-shaped thin film piece 21 to pivot to open the orifice plate 20, and the lung ventilation enters the second air ventilation pipeline 14 through the opening of the orifice plate 20; at the same time, the sound wave output by the mobile phone 30 via the audio output hole 12 propagates towards the audio input hole 11 through the opening of the orifice plate 20, and the mobile phone 30 acquires the sound wave propagated to the audio input hole 11 and measures the opening area of the orifice plate 20 and the transmission coefficient of the orifice plate 20 after processing, and then measures the flow rate of the to-be-detected lung ventilation through relevant physical calculation formulas.

[0042] In one embodiment, an installation part is arranged in the air flow pipeline 10, and the orifice plate 20 abuts against the installation part.

[0043] In one example of this embodiment, the installation part is a bump, a boss or a clamping point, and any outer side of the orifice plate 20 abuts against the bump, the boss or the clamping point and is fixed; and the orifice plate 20 can be disassembled or taken out from one end of the first air ventilation pipeline 13.

[0044] In one example of this embodiment, the installation part is an installation hole, the installation hole is arranged on the pipe wall of the air flow pipeline 10, and the installation hole penetrates through the pipe wall, so that the limit screw screwed in from the installation hole can abut against the orifice plate 20;

[0045] In addition, the aperture of the installation hole is smaller than the thickness of the orifice plate 20; in this way, the propagation of sound waves can be not affected.

[0046] In one example of this embodiment, the material of the orifice plate 20 is an elastic material.

[0047] Among them, the elastic material can be selected from propylene plastics or other environmentally friendly materials with similar functions, and this example is not limited thereto.

[0048] In one example of this embodiment, a sound pressure processing program is built in the mobile phone 30, and it can calculate the gas flow rate passing through the orifice plate 20 according to the sound pressure difference between the front and back sides of the orifice plate 20.

[0049] In an example of this embodiment, the sound pressure processing program includes: a sound wave driving module, a sound wave receiving module, a sound wave conversion and processing module, and a flow rate measurement module;

[0050] The sound wave driving module is used to generate a control instruction to drive the speaker of the mobile phone 30 to emit a specified sound wave;

[0051] The sound wave receiving module, based on the microphone of the mobile phone 30, receives the sound wave propagated to the audio input hole 11;

[0052] The sound wave conversion and processing module performs analog-to-digital conversion and numerical quantization according to the sound intensity / sound pressure of the received sound wave, and obtains a sound pressure difference by comparing the sound pressure of the output sound wave;

[0053] The flow rate measurement module calculates the opening area of the orifice plate 20 according to the pre-calibrated transmission coefficient of the orifice plate 20 and the measured sound pressure difference, and then infers the flow rate of the lung ventilation to be measured.

[0054] In this example, both the sound wave driving module and the sound wave receiving module can be directly called according to the default driver program interfaces of the speaker and microphone of the mobile phone 30, or can be applied with simple modification.

[0055] In an example of this embodiment, the construction of the sound pressure processing program is mainly based on the sound wave conduction theory and the orifice plate flowmeter measurement principle;

[0056] Among them, the sound wave conduction theory: when the sound wave propagates from the air duct 13 with an area S1 to another pipe with a cross-sectional area S2 at the end (i.e., the air duct 14), the transmission coefficient t of the sound pressure can be deduced according to the law of conservation of mass p as:

[0057]

[0058] It can be seen from this that after the sound wave sent by the audio output port of the mobile phone 30 enters the air duct 13 through the audio output hole 12, it then passes through the orifice plate 20, the air duct 14, and the audio input hole 11 to reach the audio input port of the mobile phone 30. At this time, the sound pressure at the audio input hole 11 is set as P1, then there is:

[0059] P1 = t p ·P0 (2);

[0060] In the above formula (2), P0 is the sound pressure at the audio input hole 11 when the orifice plate 20 is fully open (i.e., S1 = S2).

[0061] Among them, the orifice plate flowmeter measurement principle: when the fluid flows through the orifice plate 20 with an opening area of S2, the relationship between the flow rate Q and the differential pressure ΔP generated before and after the orifice plate 20 is as follows:

[0062]

[0063] Wherein, K1 is a constant. When fluid passes through the orifice plate 20, due to the deflection effect, the opening area S2 of the orifice plate 20 increases with the flow rate, and the differential pressure ΔP on both sides of the orifice plate 20 increases with the flow rate, and the following relationship is satisfied:

[0064] ΔP=K2·S2 2 (4);

[0065] K2 is a constant. Substituting formula (3) into formula (4), we get:

[0066]

[0067] It is deduced that the flow rate Q through the orifice plate 20 is linearly related to the square of the opening area of ​​the orifice plate 20, and the coefficient K3 is a constant;

[0068] The coefficient K3 can be inferred from formula (5) by connecting a standard gas signal source with a constant flow rate and measuring the size of the opening area at the moment.

[0069] Therefore, when the coefficient K3 is predetermined, the flow rate Q passing through the orifice plate 20 can be measured by measuring the opening area S2 of the orifice plate 20, that is, the flow rate of the lung ventilation to be measured can be measured.

[0070] In an example of this embodiment, the end of the ventilation line 13 away from the orifice plate 20 is a free end, that is, the free end is in communication with the external environment, so that the lung ventilation to be tested can directly enter the airflow duct 10.

[0071] In an example of this embodiment, one end of the ventilation line 13 away from the orifice plate 20 is a free end serving as a test port of the subject, which can be aligned with the mouth and nose of the subject to achieve breathing.

[0072] In an example of this embodiment, the distance between the audio input hole 11 and the audio output hole 12 and the other is adjustable.

[0073] For example: the audio input hole 11 is configured to be slidable, while the audio output hole 12 is configured to be fixed;

[0074] Alternatively, the audio input hole 11 is configured to be fixed, and the audio output hole 12 is configured to be slidable;

[0075] The above-mentioned slidable configuration is achieved by a bellows, that is, one end of the bellows is arranged on the inner wall of the airflow duct 10, and the other end is arranged on the outer wall.

[0076] In an example of this embodiment, the device includes a fixing structure for fixing the air flow pipeline and the mobile phone.

[0077] In an example of this embodiment, the fixing structure includes a base and a mobile phone holder. A limiting groove for limiting the air flow pipeline is provided on the base, and the mobile phone holder is arranged on the base for clamping and fixing the mobile phone.

[0078] In an example of this embodiment, the transmittance coefficient of the orifice plate is denoted as t p , t p The calculation of satisfies the above formula (1), that is:

[0079]

[0080] wherein, S1 is the inner cross-sectional area of the first ventilation pipeline, and S2 is the opening area of the orifice plate.

[0081] As Figure 4 shown, in one embodiment, a method for measuring pulmonary ventilation function based on the principle of sound diffraction is used for the device for measuring pulmonary ventilation function based on the principle of sound diffraction as described above. The method includes the following steps S101 - S111:

[0082] S101. Set the mobile phone 30 and the air flow pipeline 10 so that the audio input hole 11 is coupled with the audio input port of the mobile phone 30, and the audio output hole 12 is coupled with the audio output port of the mobile phone 30;

[0083] S103. Output sound waves from the audio output port of the mobile phone 30 to the audio output hole 12, obtain the sound waves propagated to the audio input hole 11, and obtain the sound pressure P0 of the audio input hole 11;

[0084] S105. Set the orifice plate 20 in the air flow pipeline 10 between the audio input hole 11 and the audio output hole 12;

[0085] S107. Keep outputting the sound waves to the audio output hole 12. The pulmonary ventilation to be measured pushes the fan-shaped thin film 21 to pivot through the first ventilation pipeline 13 to open the orifice plate 20, and the opened orifice plate 20 allows the pulmonary ventilation to enter the second ventilation pipeline 14;

[0086] S109. Then obtain the sound waves propagated to the audio input hole 11, and obtain the sound pressure P1 of the audio input hole 11;

[0087] S111. Measure the flow rate of the pulmonary ventilation to be measured through relevant physical calculation formulas.

[0088] In an example of this embodiment, the step of measuring the flow rate of the pulmonary ventilation to be measured through relevant physical calculation formulas specifically includes:

[0089] Calibrate the inner cross-sectional area of the calibration vent pipe 11, denoted as S1;

[0090] Calculate the opening area of the orifice plate 20, denoted as S2, which satisfies:

[0091]

[0092]

[0093] where K3 is a constant, and Q represents the flow rate of the lung ventilation to be measured.

[0094] In this example, for the calibration of the coefficient K3, the above formulas (3) and (4) can be referred to; details are not described here again.

[0095] In an example of this embodiment, in step S105, the orifice plate 20 is arranged at the center of the air flow pipe 10 between the audio input hole 11 and the audio output hole 12, that is, at the geometric center between the audio input hole 11 and the audio output hole 12; in this way, the design of the calculation model can be simplified, and the calculation processing efficiency and accuracy can be improved.

[0096] An apparatus for measuring lung ventilation function based on the principle of sound diffraction provided by an embodiment of the present invention, and a method for measuring lung ventilation function based on the principle of sound diffraction are provided based on this apparatus. Based on the principle of sound diffraction, the sound pressures (i.e., P0, P1) at the audio input hole 11 before and after the orifice plate 20 is arranged, and related parameters that can be pre-calibrated (such as K3) are measured, and the flow rate of the lung ventilation to be measured is measured, so that the lung ventilation function test can be realized at low cost. When used in cooperation with a smart phone, it is very convenient and easy to promote.

[0097] The above embodiments only represent several implementation manners of the present invention. The description is relatively specific and detailed, but it cannot be understood as a limitation to the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.

[0098] The above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A lung ventilation function measuring device based on the principle of sound diffraction, characterized in that, The device includes an air flow pipeline and an orifice plate; The pipe wall of the air flow pipeline is provided with an audio input hole and an audio output hole. The audio input hole is coupled to the audio input port of the mobile phone, and the audio output hole is coupled to the audio output port of the mobile phone; The orifice plate is arranged in the air flow pipeline and is located between the audio input hole and the audio output hole. The orifice plate includes a plurality of fan-shaped thin film pieces, and the plurality of fan-shaped thin film pieces are pivotally arranged in a circular arrangement; A section of the air flow pipeline close to the audio output hole is a first ventilation pipeline, and a section of the air flow pipeline close to the audio input hole is a second ventilation pipeline; Among them, the lung ventilation to be measured passes through the first ventilation pipeline and then pushes the fan-shaped thin film piece to pivot to open the orifice plate. The orifice plate opening allows the lung ventilation to enter the second ventilation pipeline; at the same time, the sound wave output by the mobile phone via the audio output hole propagates towards the audio input hole through the orifice plate opening. The mobile phone acquires the sound wave propagating to the audio input hole and measures the opening area of the orifice plate and the transmission coefficient of the orifice plate after processing, and then measures the flow rate of the lung ventilation to be measured through relevant physical calculation formulas, specifically including: Calibrate the inner cross-sectional area of the first ventilation pipeline, denoted as S1; Calculate the opening area of the orifice plate, denoted as S2, which satisfies: , , where K3 is a constant, Q represents the flow rate of the lung ventilation to be measured, P0 is the first sound pressure of the audio input hole, P1 is the second sound pressure of the audio input hole, output sound waves from the audio output port of the mobile phone to the audio output hole, obtain the sound waves propagated to the audio input hole, and get the first sound pressure P0 of the audio input hole. Set the orifice plate in the air flow pipeline between the audio input hole and the audio output hole; keep outputting sound waves to the audio output hole. The lung ventilation to be measured pushes the fan-shaped thin film to pivot through the ventilation pipeline 1 to open the orifice of the orifice plate, and the opened orifice of the orifice plate allows the lung ventilation to enter the ventilation pipeline 2; then obtain the sound waves propagated to the audio input hole again, and get the second sound pressure P1 of the audio input hole. The orifice plate is arranged on the geometric center line of the audio input hole and the audio output hole. The apertures of the audio input hole and the audio output hole are the same. An installation part is arranged in the air flow pipeline. The orifice plate abuts against the installation part. The material of the orifice plate is an elastic material. The installation part is an installation hole, a bump, a boss or a clamping point. The installation hole is arranged on the pipe wall of the air flow pipeline and penetrates through the pipe wall.

2. The lung ventilation function measuring device based on the principle of sound diffraction according to claim 1, characterized in that Among the audio input hole and the audio output hole, the distance between one of them and the other is adjustable.

3. The lung ventilation function measuring device based on the principle of sound diffraction according to claim 1, wherein The device includes a fixing structure for fixing the air flow pipeline and the mobile phone.

4. The lung ventilation function measuring device based on the principle of sound diffraction according to claim 3, characterized in that The fixing structure includes a base and a mobile phone holder. The base is provided with a limiting groove for limiting the air flow pipeline, and the mobile phone holder is arranged on the base for clamping and fixing the mobile phone.

5. The lung ventilation function measuring device based on the principle of sound diffraction according to claim 1, characterized in that, The transmission coefficient of the orifice plate is denoted as \(t_p\), and the calculation of \(t_p\) satisfies: , where \(S_1\) is the inner cross-sectional area of the first ventilation pipeline, and \(S_2\) is the opening area of the orifice plate.

6. A method for measuring pulmonary ventilation function based on the principle of sound diffraction, characterized in that, For the lung ventilation function measuring device based on the sound diffraction principle according to any one of claims 1 to 5, the method includes the following steps: Set the mobile phone and the air flow pipeline so that the audio input hole is coupled to the audio input port of the mobile phone and the audio output hole is coupled to the audio output port of the mobile phone; Output a sound wave from the audio output port of the mobile phone to the audio output hole, acquire the sound wave propagating to the audio input hole, and obtain the first sound pressure P0 of the audio input hole; Arrange the orifice plate in the air flow pipeline between the audio input hole and the audio output hole; Keep outputting the sound wave to the audio output hole. The lung ventilation to be measured passes through the first ventilation pipeline and then pushes the fan-shaped thin film piece to pivot to open the orifice plate. The orifice plate opening allows the lung ventilation to enter the second ventilation pipeline; Then acquire the sound wave propagating to the audio input hole and obtain the second sound pressure P1 of the audio input hole; Measure the flow rate of the lung ventilation to be measured through relevant physical calculation formulas.

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