Lung function instrument with jitter and direction detection, sensor handle and detection method

Abstract

The present invention provides a pulmonary function instrument, a sensor handle and a detection method with jitter and direction detection, which include a differential pressure sensor and a triaxial acceleration sensor. During the pulmonary function test, the triaxial acceleration sensor can effectively determine whether the sensor handle is in the test position and monitor the jitter condition of the sensor handle, thereby ensuring the accuracy of the test baseline of the pulmonary function instrument and reducing the detection error. Therefore, the pulmonary function instrument with the functions of jitter and direction detection described in the present invention has extremely high application value.

Description

Technical Field

[0001] The present invention relates to the field of medical devices, and particularly to a pulmonary function instrument with jitter and direction detection, as well as a supporting sensor handle and detection method. Background Art

[0002] In recent years, portable handheld pulmonary function instruments have been developed and emerged in the field of pulmonary function detection. They mainly measure and analyze parameters such as vital capacity and maximum voluntary ventilation volume, which are helpful for the diagnosis, disease grading, and efficacy judgment of common respiratory diseases such as bronchial asthma, chronic obstructive pulmonary disease, and chronic cough, as well as the risk assessment of surgical operations. They can be used for physical examinations in community hospitals, schools, or major hospitals, epidemiological investigations, bedside examinations in wards, and home use, etc.

[0003] One of the key components of a handheld electronic pulmonary function instrument is a differential pressure sensor for detecting changes in air flow during exhalation or inhalation. Currently, silicon materials are commonly used as differential pressure sensors. The working principle is to form multiple diffusion resistors with equal resistance values on a silicon elastic diaphragm (elastic sensitive element) to form a Wheatstone bridge. The resistance value changes are generated by the deformation of the silica gel membrane, thereby obtaining the corresponding parameters required for measurement. However, the position sensitivity of such differential pressure sensors is very high. Due to the gravity of the silica gel membrane itself, when the hand of the tester holding the handle of the pulmonary function instrument shakes or the handle deviates from the test position by a large amount, the silica gel membrane will deform. The vibration or change in direction of the sensor before testing will cause misjudgment of the differential pressure sensor and wrongly give the pulmonary function test result. Or this vibration or change in direction before testing will be used as the test baseline, resulting in a large test error.

[0004] How to improve the detection accuracy of pulmonary function instruments using such differential pressure sensors has become an urgent problem to be solved currently.

[0005] The mainstream pulmonary function instruments on the market are based on the principle of differential pressure flow meters. Differential pressure flow meters have the advantages of high accuracy, little influence by environmental temperature, and long service life. A differential pressure flow meter includes two parts: a flow transmitter and a differential pressure sensor. The flow transmitter realizes the primary conversion of gas flow velocity and differential pressure. According to the different magnitudes of the gas flow velocity flowing through the transmitter, corresponding pressure differences, that is, differential pressure signals, are generated at both ends of the transmitter. Generally, a throttle tube, orifice plate, sieve mesh, etc. are used; the differential pressure sensor then converts the differential pressure signal that has a certain relationship with the flow rate into an electrical signal, which is processed and then converted into a digital signal. Finally, various pulmonary function parameters and curves are calculated and displayed by a microprocessor. For example, Chinese patents 201720594878.1, 201710538777.7, and 201710705110.1 record pulmonary function instruments with throttle tubes and differential pressure sensors.

[0006] Differential pressure sensors usually use silicon piezoresistive technology, integrating pressure strain gauges and thin-film resistor networks precisely calibrated by lasers on silicon wafers. When there is a pressure difference between the two sides of the strain gauge, the strain gauge will produce a slight deformation, causing the impedance of the resistor network to change accordingly, thereby realizing differential pressure detection. However, the strain gauge is affected by gravity, and the strain gauge itself will have different subtle deformations when placed in different directions. Although it is very small, it will also cause the impedance of the resistor network to change. Therefore, the differential pressure sensor is sensitive to position, and movement or shaking will cause impedance output changes. Although many differential pressure sensor manufacturers have adopted various technologies to minimize position sensitivity, such as using two sets of symmetrical resistor network compensation and other technologies, they cannot completely eliminate position sensitivity. Differential pressure sensors are generally installed in the sensor handle of the pulmonary function meter. For large pulmonary function meters, the sensor handle is fixed on the bracket, and the position of the differential pressure sensor is also fixed. The position sensitivity of the differential pressure sensor does not affect the detection accuracy. However, for handheld spirometers, the differential pressure sensor may move, change direction, or shake during the test. Therefore, portable spirometers usually require the sensor to be in the same direction as during the test and to be as still as possible during zero-point testing and normal exhalation testing. These requirements can solve most problems, but there are still many cases where the test data does not meet the quality control requirements of pulmonary function tests due to incorrect sensor direction or shaking during the test. The number of repeated tests has to be increased, which wastes time, and multiple forced exhalation tests make patients more tired. Summary of the invention

[0007] In order to overcome the above disadvantages, one of the purposes of the present invention is to provide a sensor handle for a pulmonary function meter, comprising a differential pressure sensor, a main control board and a triaxial acceleration sensor, wherein the triaxial acceleration sensor and the differential pressure sensor are mounted on the main control board and are respectively connected to a microprocessor. The triaxial acceleration sensor is used to detect the shaking and directional inclination of the sensor handle.

[0008] Furthermore, the sensor handle includes an upper cover and a lower cover, which are assembled together to form an inner cavity, and the main control board loaded with the three-axis acceleration sensor and the pressure difference sensor is installed in the inner cavity of the sensor handle.

[0009] Furthermore, the main control board is also provided with a signal conditioning circuit and an A / D conversion circuit.

[0010] Furthermore, the differential pressure signal output by the differential pressure sensor is converted into a digital signal through a signal conditioning circuit and an A / D conversion circuit, and is connected to a microprocessor circuit through a serial peripheral interface bus. The xyz three-axis acceleration digital signal output by the three-axis acceleration sensor is connected to a microprocessor circuit through a serial peripheral interface bus.

[0011] The present invention also provides a pulmonary function instrument, comprising a differential pressure flow meter, a microprocessor, a sensor handle and a three-axis acceleration sensor.

[0012] Furthermore, a three-axis acceleration sensor is installed in the sensor handle.

[0013] The differential pressure flowmeter includes a flow transmitter and a differential pressure sensor. The triaxial acceleration sensor and the differential pressure sensor are fixed on the main control board and are connected to the microprocessor respectively.

[0014] Further, the flow transmitter is selected from a throttling tube.

[0015] The present invention also provides a method for detecting the position and jitter of a sensor handle, including installing a three-axis acceleration sensor on the sensor handle, and using the three-axis acceleration sensor to detect the jitter of the handle and / or the direction and position of the handle. The characteristic value of the handle jitter detection is the absolute value of the acceleration difference between adjacent moments, and the judgment method is to obtain the absolute value of the difference between the acceleration value at the current moment and the acceleration value at the previous moment. If it is greater than a jitter threshold value in a preset number of consecutive times, it is determined that the handle is jittering; if it is less than the jitter threshold value, it is determined that the handle is stationary; the characteristic value of the handle direction and position detection is the three-axis acceleration component value, and the judgment method is to obtain the current three-axis acceleration component value. If any component value exceeds the threshold range in a preset number of consecutive times, it is determined that the handle direction is incorrect; if it does not exceed the threshold range, it is determined that the handle direction is correct.

[0016] The preset number of consecutive times may be one or more times, such as ten times.

[0017] The present invention also provides a method for measuring lung function parameters using a pulmonary function meter, comprising the following steps: (1) providing a handheld pulmonary function meter with a sensor handle, the pulmonary function meter comprising a differential pressure flowmeter, a microprocessor and a three-axis acceleration sensor, the differential pressure flowmeter comprising a flow transmitter and a differential pressure sensor, the three-axis acceleration sensor and the differential pressure sensor being installed in the sensor handle; (2) the subject blows air into the flow transmitter; (3) using the three-axis acceleration sensor and the aforementioned method for detecting the direction and shaking of the sensor handle to determine the direction and shaking of the sensor handle; if it is determined that the sensor handle is in a shaking state and / or the handle direction is not in a test position, a signal prompt is given or the detection is stopped directly; if it is determined that the handle is in a correct detection position and state, the detection continues; (4) when it is determined that the handle is in a correct detection position and state, the differential pressure sensor converts the differential pressure signal having a certain relationship with the flow into an electrical signal, which is converted into a digital signal after processing, and finally the microprocessor calculates and displays various lung function parameters and curves.

[0018] The present invention also provides a pulmonary function parameter testing system with jitter and direction detection, including a differential pressure sensor, a signal conditioning circuit, an A / D conversion circuit, a microprocessor circuit, a three-axis acceleration sensor, and a power management circuit. The differential pressure sensor outputs a differential pressure signal, which is converted into a digital signal through the signal conditioning circuit and the A / D conversion circuit and connected to the microprocessor circuit. The three-axis acceleration sensor outputs xyz three-axis acceleration digital signals and is connected to the microprocessor circuit. The power management circuit is respectively connected to the signal conditioning circuit, the A / D conversion circuit, the microprocessor circuit, and the three-axis acceleration sensor.

[0019] Further, the digital signal converted by the A / D conversion circuit is connected to the microprocessor circuit through the SPI bus.

[0020] Further, the xyz three-axis acceleration digital signals output by the three-axis acceleration sensor are connected to the microprocessor circuit through the SPI bus.

[0021] The three-axis acceleration sensor is a sensor that can sense acceleration and convert it into an available output signal. The three-axis acceleration sensor can detect changes in the inclination angles of up, down, left, and right. Using the acceleration sensor to detect the vibration / shake amplitude of a handheld device can comprehensively and accurately reflect the motion properties of an object. The differential pressure sensor selected is a piezoresistive silicon pressure sensor.

[0022] The advantages of installing the three-axis acceleration sensor on the handheld pulmonary function instrument in the present invention are: (1) It can timely and effectively determine whether the handle with the differential pressure sensor is in the test position, reducing the detection error caused by abnormal deformation of the silicone membrane of the differential pressure sensor. (2) During the test process, it monitors the hand jitter situation of the tester. If it is determined that the jitter is very large, the detection can be immediately stopped, thereby ensuring the stability of the baseline and guaranteeing the measurement accuracy. Description of the Drawings

[0023] Figure 1 Schematic diagram of the acceleration in the corresponding x, y, and z axis directions of the three-axis acceleration sensor;

[0024] Figure 2 Schematic diagram of one side of the main control board installed with the differential pressure sensor and the three-axis acceleration sensor;

[0025] Figure 3 Schematic diagram of the other side structure of the main control board installed with the differential pressure sensor and the three-axis acceleration sensor;

[0026] Figure 4 Circuit block diagram;

[0027] Figure 5 Test process block diagram for detecting the jitter and direction of the sensor handle using the three-axis sensor;

[0028] Figure 6 Schematic diagram of the first type of spirometry instrument with a three-axis sensor;

[0029] Figure 7 Schematic diagram of the second type of spirometer with a three-axis sensor;

[0030] FIG8 is a VT time-volume curve and a FT time-flow curve of the control group in Example 1;

[0031] FIG9 VT time-volume curve and FT time-flow curve of the experimental group in Example 1;

[0032] FIG10 is a VT time-volume curve and a FT time-flow curve of the control group in Example 2;

[0033] Figure 11 shows the VT time-volume curve and FT time-flow curve of the experimental group in Example 2. DETAILED DESCRIPTION

[0034] The handheld pulmonary function meter includes a differential pressure flowmeter, a microprocessor and a sensor handle, in which a triaxial acceleration sensor is installed. The differential pressure flowmeter includes a flow transmitter and a differential pressure sensor. The flow transmitter can be selected from a throttling tube, an orifice plate, a screen, etc., which realizes a primary conversion of gas flow rate and pressure difference. According to the different air flow speeds flowing through the transmitter, a corresponding pressure difference is generated at both ends of the transmitter, that is, a differential pressure signal that has a certain relationship with the flow rate. The differential pressure sensor then converts the differential pressure signal into an electrical signal and then into a digital signal. The microprocessor calculates and displays various pulmonary function parameters and curves.

[0035] The three-axis acceleration sensor is used to detect the shaking and direction inclination of the sensor handle, so as to judge the state of the sensor handle during the zero point detection and exhalation detection process. If the sensor handle is in an incorrect direction or shakes, the detection is stopped and a prompt is given to keep the correct direction and keep as still as possible until the direction is correct and the sensor handle is still. This can effectively avoid invalid detection caused by operational errors and greatly improve detection efficiency.

[0036] like Figure 1 The three-axis acceleration sensor shown in the figure, when the three-axis acceleration sensor is in a moving state, the corresponding acceleration values in the x, y, and z directions will change; when the three-axis acceleration sensor is in a stationary state, only gravity is applied to it, and the acceleration outputs of the three axes are the components of gravity acceleration in the three axes. The three-axis acceleration sensor is fixed on the sensor handle. When the handle is stationary in a certain direction, the acceleration outputs of the three axes are the components of gravity acceleration in the three axes in that direction. When the direction of the handle changes, the components of gravity acceleration in the three axes will also change, so the direction and position of the handle and the shaking of the handle can be judged.

[0037] The handle's jitter detection feature value is the absolute value of the acceleration difference between adjacent moments, representing the rate of change of acceleration between adjacent moments. Get the absolute value of the difference between the acceleration value at the current moment and the acceleration value at the previous moment. If it is greater than the jitter threshold within a preset number of consecutive times, the handle is determined to be jittery; if it is less than the jitter threshold, the handle is determined to be stationary. In a more specific example, take the acceleration values in the three directions of xyz, and compare the changes in the acceleration values in these three directions at adjacent moments. If the acceleration difference in one or more directions exceeds the threshold, it means that the handle is jittering.

[0038] The handle direction position detection characteristic value is the three-axis acceleration component value, which represents the angle between the three-axis direction and the gravity direction. The smaller the angle, the larger the output acceleration component. When the handle is in different directions, the gravity components in the xyz directions are different. Get the current three-axis acceleration component value. If any component value is greater than or less than the direction threshold range within the preset number of consecutive times, the handle direction is determined to be incorrect; if it meets the direction threshold range, the handle direction is determined to be correct.

[0039] The preset number of consecutive times may be several times, for example, ten times in a row, or other times.

[0040] In such Figure 2 and 3 In the design shown, the three-axis acceleration sensor 1 and the differential pressure sensor 2 are fixed on the main control board 3 and are respectively connected to the microprocessor circuit 91. The main control board 3 is installed in the sensor handle of the pulmonary function meter. The throttle tube is plugged into the connecting seat 4 and connected to the differential pressure sensor through the air duct 5 to achieve a primary conversion of gas flow rate and pressure difference. According to the different air flow velocities flowing through the throttle tube, a corresponding pressure difference is generated at both ends of the throttle tube to form a differential pressure signal. The differential pressure sensor converts the differential pressure signal that has a certain relationship with the flow rate into an electrical signal, which is converted into a digital signal after processing, and the microprocessor calculates and displays various lung function data. Depending on the throttle tube, the number of differential pressure sensors is not limited. For example, the differential pressure sensor can be one or more. Figure 2 The main control board is also equipped with an A / D conversion circuit 92 and a signal conditioning circuit 93.

[0041] Figure 4 This is a schematic diagram of the circuit principle associated with the sensor, including the differential pressure sensor, signal conditioning circuit, A / D conversion circuit, microprocessor circuit, triaxial acceleration sensor and power management circuit. When the power is turned on to start the lung function test, the person being tested blows into the flow transmitter, and the signal measured by the differential pressure sensor is amplified, converted to digital and sent to the microprocessor. At the same time, the signal measured by the triaxial acceleration sensor is transmitted to the microprocessor to provide data parameters of the sensor handle shaking and direction inclination.

[0042] Combined with Figure 5 the test process block diagram shown, a method for using a three-axis acceleration sensor to determine the direction position and jitter condition of a sensor handle is further described, including the following steps: (1) The three-axis acceleration sensor installed in the sensor handle is powered on and reset. (2) Initialize the three-axis acceleration values. (3) Obtain the three-axis acceleration values at the current moment. (4) Calculate the absolute value of the difference between the three-axis acceleration values and the acceleration values at the previous adjacent moment. (5) Compare the absolute value of the difference with a preset jitter threshold. If it is greater than the jitter threshold, further determine whether the absolute value of the difference is greater than the jitter threshold within a preset number of consecutive times (for example, ten consecutive times). If not, return to step 3 again. If so, it is determined that the handle is jittering. If it is less than the jitter threshold, it is determined that the handle is stationary. (6) When it is determined that the handle is stationary, calculate the acceleration component values and compare the component values with a preset angle threshold range. If the component values do not exceed the preset angle threshold, it is determined that the handle direction is correct. If the component values exceed the angle threshold range, further determine whether the component values exceed the angle threshold range within a preset number of consecutive times (for example, ten consecutive times). If not, return to step 3 again. If so, it is determined that the handle direction is incorrect.

[0043] To prevent the sensor handle from being too sensitive to jitter and incorrect directions, a step of determining whether the absolute value of the difference is greater than the jitter threshold or whether the component values exceed the angle threshold range within a preset number of consecutive times is added during the test process. This is an optional step according to the overall situation of the system.

[0044] A pulmonary function parameter test system with jitter and direction detection includes a differential pressure sensor, a signal conditioning circuit, an A / D conversion circuit, a microprocessor circuit, a three-axis acceleration sensor, and a power management circuit. The differential pressure sensor outputs a differential pressure signal, which is converted into a digital signal through the signal conditioning circuit and the A / D conversion circuit and connected to the microprocessor circuit through a Serial Peripheral Interface (SPI) bus. The three-axis acceleration sensor outputs xyz three-axis acceleration digital signals and is connected to the microprocessor circuit through the SPI bus. The power management circuit is respectively connected to the signal conditioning circuit, the A / D conversion circuit, the microprocessor circuit, and the three-axis acceleration sensor.

[0045] Such as Figure 2 、 3The handheld pulmonary function instrument with a sensor handle shown in FIGS. 6 includes a sensor handle 6, a throttle tube 7, and a main unit 8. The sensor handle 6 includes an upper cover 61 and a lower cover 62. The upper cover and the lower cover are snap-fitted together to form an inner cavity. A main control board 3 loaded with a three-axis acceleration sensor 1 and a differential pressure sensor 2 is installed in the inner cavity of the sensor handle. The top end of the sensor handle is connected to the bottom of a throttle tube connector 4. As shown in Figure 2 and 3 In the illustrated embodiment, the connector 4 is provided with a hole column socket 41 that mates with the pressure tapping hole column of the throttle tube. An air duct interface 42 is installed on the hole column socket. One end of the air duct is connected to the air duct interface, and the other end is connected to the differential pressure sensor. During use, the throttle tube 7 is installed on the throttle tube connector 4 and connected to the differential pressure sensor through the air duct to achieve a primary conversion of gas flow rate and differential pressure. The main unit 8 is equipped with a data storage and output system, such as a memory, a display screen 81, an audio device, etc. The sensor handle transmits the detected data to the main unit through a data transmission system, and the data transmission system can be selected from methods such as a data cable, Bluetooth transmission, etc.

[0046] For a handheld pulmonary function instrument with three pressure tapping hole columns on the throttle tube, namely a low-pressure pressure tapping hole column, a first high-pressure pressure tapping hole column, and a second high-pressure pressure tapping hole column, the corresponding connector is also provided with three hole column sockets. The main control board is arranged with a first differential pressure sensor, a second differential pressure sensor, and a three-axis acceleration sensor. After the throttle tube is inserted into the throttle tube connector, the first high-pressure pressure tapping hole column is connected to the positive pressure end of the first differential pressure sensor through an air duct 5, and the second high-pressure pressure tapping hole column is connected to the positive pressure end of the second differential pressure sensor through an air duct 5. The low-pressure ends of the two differential pressure sensors are respectively connected to the low-pressure pressure tapping hole column through a tee 43.

[0047] As shown in Figure 7 Another handheld pulmonary function instrument with a sensor handle includes a sensor handle 6 with a display screen 81 and a throttle tube 7. A main control board loaded with a three-axis acceleration sensor and a differential pressure sensor is installed in the sensor handle, and the sensor handle also includes a microprocessor. The throttle tube 7 is installed on the sensor handle and connected to the differential pressure sensor through an air duct. The throttle tube only includes one high-pressure pressure tapping hole column and one low-pressure pressure tapping hole column, and the corresponding connector is also provided with two hole column sockets.

[0048] A method for measuring pulmonary function parameters using the pulmonary function instrument with a three-axis acceleration sensor according to the present invention includes the following steps:

[0049] (1) Provide a handheld pulmonary function instrument, which includes a differential pressure flowmeter, a microprocessor, and a three-axis acceleration sensor. The differential pressure flowmeter includes a flow transmitter and a differential pressure sensor. The three-axis acceleration sensor and the differential pressure sensor are installed in the sensor handle.

[0050] (2) The tested person exhales into the flow transmitter (such as a throttle tube).

[0051] (3) Use the triaxial acceleration sensor and the foregoing method to judge the direction position and jitter situation of the sensor handle. If it is judged that the sensor handle is in a jitter state and / or the handle direction is not in the test position, a signal prompt is given, or the detection is directly stopped (for example, stop the detection and prompt to maintain the correct direction and keep as still as possible); if it is judged that the handle is in the correct detection position and state, the detection continues.

[0052] (4) When it is judged that the handle is in the correct detection position and does not jitter, the differential pressure sensor converts the differential pressure signal related to the flow into an electrical signal, which is processed and then converted into a digital signal. Finally, the microprocessor calculates and displays various pulmonary function parameters and curves.

[0053] Example 1

[0054] The handheld pulmonary function instrument (experimental group) with the triaxial acceleration sensor turned on and the pulmonary function instrument (control group) with the triaxial acceleration sensor turned off described in the present invention are used to detect the forced vital capacity (FVC) of the tested person. The pulmonary function instruments of the experimental group and the control group are the same except for the on / off of the triaxial acceleration sensor. The experimental process is designed such that the sensor handle jitters before the end, and the actual FVC value designed in the experiment is 1.74 L.

[0055] The experimental results are as Figure 8 and 9 shown. Due to the jitter of the sensor handle, the zero output of the differential pressure sensor fluctuates. The FVC value measured by the control group is 1.80 L, which is larger than the actual FVC detection result. The FVC value measured by the experimental group is 1.74 L, which is consistent with the actual FVC. The experimental results show that since the acceleration sensor is not turned on in the control group, it is impossible to judge the jitter situation of the handle, resulting in a larger FVC detection in the control group and giving a wrong result. In the experimental group, the step of turning on the triaxial acceleration sensor to detect the jitter situation of the handle effectively judges the jitter situation of the handle, avoids wrong detection, and gives an accurate result.

[0056] Example 2

[0057] The handheld pulmonary function instrument (experimental group) with the triaxial acceleration sensor turned on and the pulmonary function instrument (control group) with the triaxial acceleration sensor turned off described in the present invention are used to detect the forced vital capacity (FVC) of the tested person. The pulmonary function instruments of the experimental group and the control group are the same except for the on / off of the triaxial acceleration sensor. The experimental process is designed such that the handle direction changes before the end, and the actual FVC value designed in the experiment is 3.19 L.

[0058] The experimental results are as follows Figure 10 and 11 shown. Due to the change in the handle direction, the zero output of the differential pressure sensor increases. The FVC value measured by the control group is 3.65 L, which is larger than the actual FVC test result. The FVC value measured by the experimental group is 3.19 L, which is consistent with the actual FVC. The experimental results show that since the triaxial acceleration sensor was not turned on in the control group, it was impossible to judge the change in the handle direction, resulting in an overestimated FVC detection in the control group and an incorrect result. In the experimental group, the step of turning on the triaxial acceleration sensor to detect the change in the handle direction was added, effectively judging the change in the handle direction, avoiding false detection, and giving an accurate result.

Claims

1. A sensor handle for a pulmonary function instrument, comprising a differential pressure sensor and a main control board, characterized in that, It also includes a three-axis acceleration sensor. The three-axis acceleration sensor and the differential pressure sensor are installed on the main control board and are respectively connected to the microprocessor. The three-axis acceleration sensor is installed on the sensor handle, and the three-axis acceleration sensor is used for detecting the jitter of the handle and / or detecting the direction and position of the handle. The characteristic value of the jitter detection of the handle is the absolute value of the acceleration difference between adjacent moments. The judgment method is to obtain the absolute value of the difference between the acceleration value at the current moment and the acceleration value at the previous moment. If the absolute value is greater than the jitter threshold in a preset number of consecutive times, it is determined that the handle has jitter; if the absolute value is less than the jitter threshold, it is determined that the handle is stationary. The characteristic value of the handle direction and position detection is the three-axis acceleration component value. The judgment method is to obtain the current three-axis acceleration component value. If any one of the component values exceeds the preset threshold range in a preset number of consecutive times, it is determined that the handle direction is incorrect; If it does not exceed the preset threshold range, it is determined that the handle direction is correct.

2. The sensor handle according to claim 1, wherein The sensor handle includes an upper cover and a lower cover. The upper cover and the lower cover are assembled together to form an inner cavity, and the main control board loaded with the three-axis acceleration sensor and the differential pressure sensor is installed in the inner cavity.

3. The sensor handle according to claim 1, characterized in that, The main control board is also provided with a signal conditioning circuit and an A / D conversion circuit.

4. A pulmonary function instrument, comprising a flow transmitter, a differential pressure sensor, a microprocessor and a sensor handle, characterized in that, It also includes a three-axis acceleration sensor. The three-axis acceleration sensor is installed on the handle, and the three-axis acceleration sensor is used for detecting the jitter of the handle and / or detecting the direction and position of the handle. The characteristic value of the jitter detection of the handle is the absolute value of the acceleration difference between adjacent moments. The judgment method is to obtain the absolute value of the difference between the acceleration value at the current moment and the acceleration value at the previous moment. If the absolute value is greater than the jitter threshold in a preset number of consecutive times, it is determined that the handle has jitter; if the absolute value is less than the jitter threshold, it is determined that the handle is stationary. The characteristic value of the handle direction and position detection is the three-axis acceleration component value. The judgment method is to obtain the current three-axis acceleration component value. If any one of the component values exceeds the preset threshold range in a preset number of consecutive times, it is determined that the handle direction is incorrect; If it does not exceed the preset threshold range, it is determined that the handle direction is correct.

5. The spirometer according to claim 4, characterized in that, The three-axis acceleration sensor and the differential pressure sensor are installed on the main control board and are respectively connected to the microprocessor. The main control board is installed in the sensor handle.

6. A method for detecting the direction and jitter of a sensor handle, including installing a triaxial acceleration sensor on the sensor handle, and using the triaxial acceleration sensor to detect the jitter of the handle and / or the direction and position of the handle. The characteristic value for detecting the jitter of the handle is the absolute value of the acceleration difference between adjacent moments. The judgment method is to obtain the absolute value of the difference between the acceleration value at the current moment and the acceleration value at the previous moment. If the absolute value is greater than the jitter threshold in a preset number of consecutive times, it is determined that the handle has jitter; if the absolute value is less than the jitter threshold, it is determined that the handle is stationary. The characteristic value for detecting the direction and position of the handle is the triaxial acceleration component value. The judgment method is to obtain the current triaxial acceleration component value. If any one of the component values exceeds the preset threshold range in a preset number of consecutive times, it is determined that the handle direction is incorrect; if it does not exceed the preset threshold range, it is determined that the handle direction is correct.

7. The method according to claim 6, characterized in that The preset number of consecutive times is 10 times.

8. A method for measuring pulmonary function parameters, including the following steps: (1) Provide a handheld pulmonary function instrument with a sensor handle. The pulmonary function instrument includes a differential pressure flowmeter, a microprocessor, a main control board, a triaxial acceleration sensor, and a sensor handle. The differential pressure flowmeter includes a flow transmitter and a differential pressure sensor. The triaxial acceleration sensor and the differential pressure sensor are installed on the main control board and are respectively connected to the microprocessor. The main control board installed with the triaxial acceleration sensor and the differential pressure sensor is installed in the sensor handle; (2) The test subject exhales into the flow transmitter; (3) Use the triaxial acceleration sensor to detect the direction and jitter of the sensor handle. If it is judged that the sensor handle is in a jitter state and / or the handle direction is not in the test position, a signal prompt is given or the detection is directly stopped; if it is judged that the handle is in the correct detection position and state, the detection continues. The characteristic value for detecting the jitter of the handle is the absolute value of the acceleration difference between adjacent moments. The judgment method is to obtain the absolute value of the difference between the acceleration value at the current moment and the acceleration value at the previous moment. If the absolute value is greater than the jitter threshold in a preset number of consecutive times, it is determined that the handle has jitter; if the absolute value is less than the jitter threshold, it is determined that the handle is stationary. The characteristic value for detecting the direction and position of the handle is the triaxial acceleration component value. The judgment method is to obtain the current triaxial acceleration component value. If any one of the component values exceeds the preset threshold range in a preset number of consecutive times, it is determined that the handle direction is incorrect; If it does not exceed the preset threshold range, it is determined that the handle direction is correct; (4) When it is judged that the handle is in the correct detection position and state, the differential pressure sensor converts the differential pressure signal related to the flow into an electrical signal, processes it and then converts it into a digital signal, and finally the microprocessor calculates and displays various pulmonary function parameters and curves.

9. The method according to claim 8, wherein The triaxial acceleration sensor is used to detect the jitter of the handle and / or the direction and position of the handle. The characteristic value of the jitter detection of the handle is the absolute value of the acceleration difference at adjacent moments. The judgment method is to obtain the absolute value of the difference between the acceleration value at the current moment and the acceleration value at the previous moment. If the absolute value is greater than the jitter threshold in a preset number of consecutive times, it is determined that the handle has jitter; if the absolute value is less than the jitter threshold, it is determined that the handle is stationary. The characteristic value of the handle direction and position detection is the triaxial acceleration component value. The judgment method is to obtain the current triaxial acceleration component value. If any one of the component values exceeds the preset threshold range in a preset number of consecutive times, it is determined that the handle direction is incorrect; If it does not exceed the preset threshold range, it is determined that the handle direction is correct.

10. The method according to claim 8, characterized in that, The main control board is also provided with a signal conditioning circuit and an A / D conversion circuit. The differential pressure sensor outputs a differential pressure signal, which is converted into a digital signal through the signal conditioning circuit and the A / D conversion circuit, and is connected to the microprocessor circuit through the serial peripheral interface bus. The triaxial acceleration sensor outputs the xyz triaxial acceleration digital signal and is connected to the microprocessor circuit through the serial peripheral interface bus.

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