Peak flow velocity meter

Abstract

The invention relates to a peak flow velocity meter, and belongs to the technical field of medical detection. The peak flow velocity meter adopts an electronic design and can automatically judge the expiration function without looking up a table by a patient; a replaceable battery and an external charging function are realized, so that the use is convenient; the exhalation nozzle can be replaced, and forgetting to turn off an instrument power supply and incorrect installation of the exhalation nozzle are prevented through the design of the proximity switch, so that the compliance of a patient is improved. The device is low in production and manufacturing cost, small in large-batch assembly difficulty, small in measurement error, good in linearity, low in airflow resistance, good in frequency response and capable of effectively evaluating the respiratory function of a patient and facilitating chronic disease management of the patient.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of medical detection, and relates to an electronic peak flow meter for chronic respiratory disease management. BACKGROUND

[0002] A peak flow meter is an instrument that can quickly and objectively reflect the peak expiratory flow (PEF) and measure the peak flow rate of a patient during exhalation, so as to evaluate the respiratory function of the patient and is widely used in the management of slow obstructive pulmonary diseases. The existing peak flow meter usually comprises a measuring tube and an indicator, and the patient moves the float in the measuring tube by blowing, and the indicator displays the corresponding peak flow rate value.

[0003] However, the existing peak flow meter displays the peak flow rate through the movement of the float, and the respiratory function cannot be directly judged from the peak flow rate. The respiratory function is also affected by factors such as gender, age, height, etc. The existing method is to evaluate the respiratory function by comparing the test scale, which is difficult to retain the trend. Electronic devices are more suitable for family management and the supervision system of class II medical devices, but the existing products lack in-place detection to prevent misuse, child / adult interchangeable mouthpieces, cloud follow-up and clinical trend data capabilities. SUMMARY

[0004] The purpose of the present application is to provide a peak flow meter with a replaceable mouthpiece assembly, which can automatically complete data acquisition, flow conversion and respiratory function determination during exhalation testing, and directly give the evaluation results to the patient, so as to facilitate the patient to perform self-management of chronic respiratory diseases and improve the use compliance.

[0005] The embodiment of the present application is implemented as follows:

[0006] The embodiment of the present application provides a peak flow meter, which comprises a mouthpiece assembly (1) and a shell (2);

[0007] The shell (2) is provided with a curved air duct (3) inside, and the curved air duct has a length of 80-140 mm, an inner diameter of 14-20 mm, and a bending angle of 30-120°;

[0008] The mouthpiece assembly (1) and the shell (2) are designed with a rigid plug-in fitting structure with a 0.05-0.20 mm assembly gap, which can be pulled up and disassembled upward by the user for replacement and cleaning. The mouthpiece includes two specifications of adult type and child type;

[0009] The shell (2) is sequentially assembled with a vane support (3A), a rotating shaft (4A), a rotor vane assembly (4), a first magnetic sensitive switch (5), a second magnetic sensitive switch (6), a control board (7) and a power module (9). The shell (2) is provided with a plastic lining (15) for limiting and fixing the control board (7);

[0010] The rotor blade assembly (4) is fixed to the rotating shaft (4A) and supported by the blade support (3A), and a magnet (4B) is arranged on the rotor blade assembly (4);

[0011] The first magnetic switch (5) is arranged opposite to the magnet (4B) and used for outputting a pulse signal when the rotor blade assembly (4) rotates with the airflow;

[0012] The second magnetic switch (6) is arranged corresponding to the mouthpiece assembly (1) and used for detecting the assembly state of the mouthpiece assembly (1) and controlling the on-off of the power supply switch device;

[0013] The display screen (11) and the key (12) are embedded and sealedly installed through the window of the shell (2) and in conduction with the control board (7);

[0014] The curved air channel (3) is formed in the shell (2), the airflow enters from the mouthpiece assembly (1) and is discharged laterally from the air outlet (14) after passing through the area of the rotor blade assembly (4);

[0015] The control board (7) is installed with a single-chip microcomputer (8), a low-dropout linear regulator (8A), a charging interface (10) and a charge-discharge module (16);

[0016] The power module (9) is in conduction with the charge-discharge module (16) and supplies power for the control system;

[0017] The key (12) is used for inputting height, age and gender and is in signal connection with the single-chip microcomputer (8);

[0018] The display screen (11) is in signal connection with the single-chip microcomputer (8) and displays the measurement results and prompt information;

[0019] When the patient blows, the airflow enters the curved air channel (3) through the mouthpiece assembly (1) to drive the rotor blade assembly (4) to rotate, the magnet (4B) periodically approaches the first magnetic switch (5) to generate a pulse signal, and the single-chip microcomputer (8) collects, calculates and converts the pulse signal to obtain the instantaneous flow and the peak expiratory flow (PEF);

[0020] The single-chip microcomputer (8) can be ESP32, STM32 and compatible models, preferably ESP32-C3-MINI;

[0021] The low-dropout linear regulator (8A) can be XC6206, AMS1117 or LP5907;

[0022] The charging interface (10) is USB Type-C, Micro-USB or Mini-USB;

[0023] The charging and discharging module (16) includes a linear charging chip and a DC-DC chip, preferably TP4056 and HX3608;

[0024] The second magnetic switch (6) triggers a power-off when it detects that the mouthpiece assembly (1) has been disassembled, which is used to remind the user to clean it and prevent forgetting to turn it off;

[0025] During measurement, the display screen (11) displays the peak flow rate (PEF) in real time, and the microcontroller (8) executes a preset program to automatically determine the exhalation function based on height, age, and gender and displays the grading results;

[0026] The algorithm for the preset program can adopt the predicted normal PEF values ​​for adults and children from the following: "Guidelines for Pulmonary Function Testing—Examination of Peak Expiratory Flow and its Variability," published in the *Chinese Journal of Tuberculosis and Respiratory Diseases*, June 2017, Vol. 40, No. 6, pp. 426-430: Adult male: PEF (L / min) = 75.6 + 20.4 × A - 0.41 × A 2 +0.002×A 3 +1.19×H; Adult female: PEF (L / min) = 282.0 + 1.79×A - 0.046×A 2 +0.68×H; In the formula, A: age (years) and H: height (cm); PEF % ≥ 80% of predicted value indicates normal or no expiratory airflow limitation; PEF % between 60% and 79% of predicted value indicates mild to moderate expiratory airflow limitation; if PEF % < 60% of predicted value, it indicates a more severe degree of expiratory airflow limitation.

[0027] The mouthpiece assembly (1) is made of medical silicone, which is safe for oral use, has low cost and is easy to process; the shell is made of polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyurethane (PU), polytetrafluoroethylene (PTFE), polycarbonate (PC), polystyrene (PS), preferably polyvinyl chloride (PVC).

[0028] Compared with the prior art, the embodiments of the present invention have at least the following advantages or beneficial effects:

[0029] (1) Automatically determine expiratory function without the need for manual table lookup;

[0030] (2) Supports both charging and battery power, making it convenient to use;

[0031] (3) The mouthpiece is replaceable and can be used by children and adults.

[0032] (4) The dual magnetic switch structure improves power management and safety of use;

[0033] (5) The magnetic sensitive blade structure is adopted, the repeatability is good, the cost is low, and the assembly is simple. BRIEF DESCRIPTION OF DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0035] Figure 1 The overall structure diagram of a peak flow meter according to an embodiment of the present application is shown in the figure.

[0036] Figure 2 The circuit connection schematic diagram of a peak flow meter according to an embodiment of the present application is shown in the figure.

[0037] Component symbols: 1 - mouthpiece assembly; 2 - shell; 3 - curved airway; 3A - blade support; 4 - rotor blade assembly; 4A - rotating shaft; 4B - magnet; 5 - first magnetic sensitive switch; 6 - second magnetic sensitive switch; 7 - control board; 8 - single-chip microcomputer; 8A - low dropout linear regulator; 9 - power module; 10 - charging interface; 11 - display screen; 12 - key; 13 - storage battery; 14 - exhaust hole; 15 - plastic lining; 16 - charging and discharging module; 17 - induction magnet. DETAILED DESCRIPTION

[0038] Embodiment

[0039] The present embodiment provides a peak flow meter, which comprises a mouthpiece assembly (1), the lower part of the mouthpiece assembly (1) is connected to a shell (2) through a rigid plug-in fitting structure, the assembly gap is 0.05-0.20 mm, the mouthpiece assembly (1) can be pulled up and disassembled for replacement and cleaning, and the mouthpiece assembly (1) comprises two specifications of adult type and child type.

[0040] The shell (2) is provided with a curved airway (3) therein, the length of the curved airway (3) is 80-140 mm, the inner diameter is 14-20 mm, and the bending angle is 30°-120°.

[0041] The shell (2) is internally provided with a blade support (3A), a rotating shaft (4A), a rotor blade assembly (4), a first magnetic sensitive switch (5), a second magnetic sensitive switch (6), a control board (7) and a storage battery (13).

[0042] The shell (2) is internally provided with a plastic lining (15) for fixing the control board (7).

[0043] The shell (2) is internally provided with a curved airway (3), and the airflow enters from the mouthpiece assembly (1) and is laterally discharged from the exhaust hole (14).

[0044] The rotor blade assembly (4) is mounted on the rotating shaft (4A) and supported by the blade support (3A), and the inductive magnet (17) is fixed on the rotor blade assembly (4);

[0045] The first magnetic switch (5) is used for detecting the rotation pulse of the rotor blade assembly (4), and the second magnetic switch (6) is used for detecting the in-place and linkage power supply of the mouthpiece assembly (1);

[0046] The display screen (11) and the key (12) are embedded and sealedly installed through the window of the shell (2) and are in signal conduction with the control board (7);

[0047] The control board (7) is installed with a single-chip microcomputer (8), a low-dropout linear voltage regulator (8A), a charging interface (10) and a charge-discharge module (16), the storage battery (13) is in conduction with the charge-discharge module (16), the key (12) is in conduction with the single-chip microcomputer (8), and the display screen (11) is in conduction with the single-chip microcomputer (8) and the low-dropout linear voltage regulator (8A);

[0048] The single-chip microcomputer (8) is selected from ESP32-C3-MINI, the low-dropout linear voltage regulator (8A) is selected from XC6206, the charging interface (10) is USB-Type C, and the charge-discharge module (16) comprises TP4056 and HX3608;

[0049] The second magnetic switch (6) is used for detecting the insertion state of the mouthpiece assembly (1), and the power supply is turned off when the mouthpiece assembly (1) is taken off, so as to prompt cleaning and avoid power consumption in the next use;

[0050] The key (12) is used for setting height, age and gender, and the display screen (11) is used for human-computer interaction and real-time display of peak expiratory flow (PEF);

[0051] The single-chip microcomputer (8) calculates the flow and PEF according to the pulse signal and executes a preset algorithm to determine the expiratory function;

[0052] The algorithm adopts the adult and child PEF normal expected value equation in the “Guidelines for Pulmonary Function Test-Expiratory Peak Flow and Its Variability Test” of the Pulmonary Function Professional Group of the Chinese Medical Association, which is published in the “Chinese Tuberculosis and Respiratory Journal”, June 2017, Vol. 40, No. 6, pp. 426-430, adult male: PEF (L / min)=75.6+20.4×A-0.41×A 2 +0.002×A 3 +1.19×H; adult female: PEF (L / min)=282.0+1.79×A-0.046×A 2+0.68 x H; in the formula A: age (years) H: height (cm); PEF%> 80% indicates normal PEF or no expiratory flow limitation, PEF% between 60% and 79% indicates mild to moderate expiratory flow limitation; if PEF% < 60%, it indicates severe expiratory flow limitation, and the algorithm is programmed into a single-chip microcomputer.

[0053] The manufacturing and assembling method of this embodiment is as follows:

[0054] 1. The shell (2), blade support (3A), and rotor blade assembly (4) are prepared by 3D printing, the material is PVC, the plastic lining (15) and exhaust hole (14) are integrally formed with the shell (2);

[0055] 2. Purchase appropriate specifications of silica gel mouthpiece assembly (1), stainless steel rotating shaft (4A), single-chip microcomputer (8), low-dropout linear regulator (8A), magnetic sensitive switch, charging interface (10), TP4056, HX3608, and capacitors, resistors, inductors, diodes, wires, and other components;

[0056] 3. The inductive magnet (17) is fixed on the rotor blade assembly (4) using light-cured glue;

[0057] 4. The rotor blade assembly (4) is installed on the rotating shaft (4A), the rotating shaft (4A) is fixed on the blade support (3A) and installed in the reserved hole of the shell (2), and light-cured glue is used for sealing to ensure smooth rotation;

[0058] 5. Burn the single-chip microcomputer (8) control program;

[0059] 6. Commission the control board (7) PCB, weld the single-chip microcomputer (8), low-dropout linear regulator (8A), charging interface (10), TP4056, HX3608, and auxiliary components;

[0060] 7. Weld the first magnetic sensitive switch (5), the second magnetic sensitive switch (6), the battery (13), the display screen (11), and the key (12);

[0061] 8. Install the magnetic sensitive switch and the battery (13) into the limiting groove of the shell (2) and fix them with light-cured glue;

[0062] 9. Install the control board (7) into the limiting groove of the plastic lining (15) and fix it on the shell (2);

[0063] 10. Seal and assemble the display screen (11) and the key (12) in the window of the shell (2) and block the gaps;

[0064] 11. The peak flow meter of the embodiment is calibrated by placing the device in a laboratory at 20 degrees Celsius (error 5 degrees Celsius), connecting the air flow source to the mouthpiece assembly (1) of the peak flow meter of the embodiment through a rigid connector, releasing standard PEF of 100 L / min, 150 L / min, 200 L / min, 300 L / min, 450 L / min, 600 L / min, and 720 L / min respectively, recording the measured data, subtracting the standard PEF from the measured data to obtain the correction value, and writing the correction value into the program through the burning contact reserved in the circuit of the control panel (7) to complete the calibration.

[0065] 12. The housing (2) is sealed with light-cured sealant, the mouthpiece assembly (1) is wiped with 75% ethanol, sealed, packed in a polyethylene bag, and packaged.

[0066] 13. The peak flow meter of the embodiment is sent to the detection workshop of Nanchang Hongyi Pharmaceutical Co., Ltd. for detection, and the test results are shown in Table 1 according to YY / T1438-2016.

[0067] Table 1:

[0068] Item Standard requirement Test result Measurement error The maximum allowable error in flow rate within the measurement range shall be ±10 L / min (0.17 L / s) or ±10% of the reading, whichever is greater. The maximum error in flow rate within the measurement range is +7% to -5% Linearity The difference between the average error of two adjacent test flow rates shall not exceed 5% of the larger of the two test flow rates. Not more than 3% of the larger of the two test flow rates Airflow resistance The resistance of airflow within the measurement range of the PEFM shall not exceed 0.35 kPa / (L / s) [0.006 kPa / (L / min)]. 0.002 kPa / (L / min) Frequency response The difference in PEF readings measured by the PEFM for A and B waveforms with the same PEF value shall not exceed 15 L / min (0.25 L / s) or 12%, whichever is greater. Not more than 9%

[0069] Compared with the prior art, the embodiment of the present application has at least the following advantages or beneficial effects:

[0070] 1. The expiration function is automatically determined without manual table checking;

[0071] 2. Charging and battery power supply are supported, and use is convenient;

[0072] 3. The mouthpiece is replaceable and can be adapted to children and adults;

[0073] 4. The double magnetic sensitive switch structure improves power management and use safety;

[0074] 5. The magnetic sensitive blade structure is used, which has good repeatability, low cost, and simple assembly;

[0075] The above is only a preferred embodiment of the present application and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A peak flow meter, characterized in that, The structure includes a mouthpiece assembly (1), a housing (2), a curved airway (3), a rotor blade assembly (4), a first magnetic switch (5), a second magnetic switch (6), a control board (7), a microcontroller (8), a power module (9), a charging interface (10), a display screen (11), and buttons (12), characterized in that: The housing (2) is provided with a curved air passage (3), the curved air passage having a length of 80-140 mm, an inner diameter of 14-20 mm, and a bending angle of 30°-120°; The mouthpiece assembly (1) is detachably installed at the air inlet end of the housing (2), and includes adult and child models; The rotor blade assembly (4) is disposed in the curved air passage (3), and a magnet is provided on the blade; The first magnetic switch (5) is disposed on the side of the magnet's movement path; The second magnetic switch (6) is located at the junction of the mouthpiece assembly (1) and the housing (2) to detect the mouthpiece assembly status and trigger a power cut-off. The control board (7) is located inside the housing (2) and is connected to the display screen (11) and the buttons (12); The microcontroller (8) is installed on the control board (7) and is used to count the pulses of the first magnetic switch (5), convert the flow rate, obtain the peak flow rate, and determine and display the exhalation function according to the user's age, height and gender. The second magnetic switch (6) triggers the power module (9) to shut down when the mouthpiece assembly (1) is disassembled.

2. The electronic peak flow meter according to claim 1, characterized in that, The mouthpiece assembly (1) has a rigid plug-in structure with a gap of 0.05 to 0.20 mm to allow it to be pulled upwards for disassembly, replacement, and cleaning.

3. The electronic peak flow meter according to claim 1, characterized in that, The housing (2) has a molded support structure inside for limiting and fixing the control plate (7).

4. The electronic peak flow meter according to claim 1, characterized in that, The microcontroller (8) is equipped with programs that can perform pulse acquisition, filtering, flow curve calculation, peak extraction and exhalation determination.

5. The electronic peak flow meter according to claim 1, characterized in that, The charging interface (10) is a Type-C interface, and the power module (9) includes a linear charging chip and a DC-DC power management chip.

6. The electronic peak flow meter according to claim 1, characterized in that, The display screen (11) is embedded and sealed by opening a window in the outer wall of the housing (2).

7. The electronic peak flow meter according to claim 1, characterized in that, The device has a Bluetooth communication module for data synchronization and trend recording with a mobile terminal APP.

8. The electronic peak flow meter according to claim 1, characterized in that, The microcontroller (8) stores peak flow calibration coefficients to correct flow data.

9. The electronic peak flow meter according to claim 1, characterized in that, The device is capable of storing at least 100 measurement records and recalling them on the display screen (11) to view trends.

10. The electronic peak flow meter according to claim 1, characterized in that, The mouthpiece assembly (1) includes two specifications: adult mouth size and child mouth size, and can be interchanged for different groups of people.

11. The mouthpiece assembly (1) according to claim 1 is made of silicone, and the material of the shell (2) includes, but is not limited to, polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyurethane (PU), polytetrafluoroethylene (PTFE), polycarbonate (PC), and polystyrene (PS).

Images