Method for generating static pressure of breathing machine tester calibration device

Abstract

The invention provides a method for generating static pressure of a breathing machine tester calibration device, and aims to accurately calibrate pressure parameters of a breathing machine tester. According to the method, a control module and a pressure parameter calibration module are integrated, a large reciprocating air cylinder and a small reciprocating air cylinder work cooperatively, and an electromagnetic valve and a digital pressure meter are combined, so that stable generation and accurate adjustment of pressure are achieved. The air leakage and deflation rate of the pipeline is determined through a pre-boosting pre-pressing test, the fine adjustment speed of the small reciprocating air cylinder is accurately controlled accordingly, and it is ensured that the static pressure is stabilized within the range of + / -1 Pa. The calibration accuracy and reliability are improved, the integration level of the calibration device is remarkably improved through the design of the shared flow parameter calibration module, the cost is reduced, the use space is reduced, and remarkable technical progress and practical application value are achieved.

Description

Technical Field

[0001] The invention relates to the field of measurement and calibration, and in particular to a parameter calibration of a breathing machine tester. Background Art

[0002] The measurement of medical instruments and equipment is an important part of hospital management. Modern medicine uses a large number of medical instruments and equipment in diagnosis, treatment and scientific research, a large part of which are measuring instruments, which is the material basis of medical work. With the continuous development of medical technology, ventilators, as an important medical device, have been widely used in clinical treatment. However, the performance and quality of ventilators have an important impact on the life safety and treatment effect of patients. At present, ventilators in hospitals are calibrated by ventilator detectors, generally once a year. The entire traceability system is not perfect enough, which is also an indirect safety hazard for ventilators. Ensuring the accuracy of gas flow, pressure, respiratory rate, and oxygen concentration measured by ventilator detectors is the key to ensuring the safety and reliability of patient treatment.

[0003] A ventilator tester is a medical device used to detect and evaluate the performance and quality of a ventilator. The main function of a ventilator tester is to detect and evaluate various performance indicators of the ventilator, such as flow, pressure, oxygen concentration, etc., so as to ensure the performance and quality of the ventilator. The accuracy and reliability of these indicators are directly related to the patient's life safety and treatment effect, so it is very necessary to accurately calibrate the ventilator tester.

[0004] The ventilator tester calibration device can effectively calibrate and trace the parameters of the ventilator tester, such as flow, tidal volume, respiratory rate, pressure, oxygen concentration, etc. It can calibrate various types of ventilator testers produced by different manufacturers to meet the requirements of the national metrology verification system for value transfer and the requirements of the establishment of social public metrology standards. The calibration device consists of: flow parameter calibration module, pressure parameter calibration module, oxygen concentration parameter calibration module and control module. The flow parameter calibration module tests and calibrates the static flow, tidal volume and respiratory rate. The pressure parameter calibration module tests and calibrates the static pressure, airway pressure and positive end-expiratory pressure. The oxygen concentration parameter calibration module tests and calibrates 21% to 100% (volume fraction). The control module uses a controller and control software to detect static flow, tidal volume, respiratory rate, static pressure, peak airway pressure, positive end-expiratory pressure and oxygen concentration, and perform process control and data processing.

[0005] In particular, traditional pressure calibration methods for ventilator testers often have many limitations, such as poor pressure stability, low calibration accuracy, complex operation, and high equipment costs. These problems seriously restrict the efficiency and effectiveness of the calibration work. The pressure source in the traditional calibration method often cannot guarantee long-term stable output, resulting in large pressure fluctuations during the calibration process, which makes it difficult to meet the needs of high-precision calibration. Especially when performing low-pressure calibration, even small pressure fluctuations may have a significant impact on the calibration results, thereby reducing the accuracy and reliability of the calibration. At the same time, in order to facilitate the connection of the calibrated tester, quick-release connectors are usually used between the device pipeline and the device under test. The quick-release connector cannot be completely sealed between the pipeline, and there will be air leakage after the pipeline is pressurized. The pressure will gradually decrease over time, and it is impossible to ensure that the pressure is stable at the setting. Summary of the invention

[0006] The present invention provides a method for generating static pressure in a ventilator tester calibration device, which is used for calibrating pressure parameters of the ventilator tester. The method has reasonable design and can accurately generate a stable pressure source, thereby ensuring the accuracy and reliability of the measurement result.

[0007] To achieve the above object, the present invention is implemented through the following technical solutions:

[0008] The ventilator tester calibration device includes a control module and a pressure parameter calibration module. The control module includes an industrial computer and a controller; the pressure parameter calibration module includes a large reciprocating cylinder, a small reciprocating cylinder, a solenoid valve, and a digital pressure gauge; the industrial computer is connected to the controller, the controller is connected to the large reciprocating cylinder and the small reciprocating cylinder, the controller is connected to the solenoid valve, and the controller is connected to the digital pressure gauge. The industrial computer is equipped with calibration software to send the calibration parameters to the controller. The controller controls the opening and closing of the solenoid valve. The controller controls the reciprocating motion of the reciprocating cylinder to generate pressure in the main pipeline, the large reciprocating cylinder roughly adjusts the pressure, and the small reciprocating cylinder finely adjusts the pressure. The controller measures the pressure in the main pipeline through a digital pressure gauge, calculates the running speed of the reciprocating cylinder, and controls the operation of the reciprocating cylinder to supplement and extract pressure.

[0009] The calibration pressure is divided into a boost and a depressurization process. Before calibration, 1 to 2 boost pre-pressure tests should be performed to ensure that the instrument under test is reliably connected through the quick-release connector. The pipeline leakage rate Q is determined by the boost pre-pressure test. During the static pressure calibration process, a large reciprocating cylinder is used to roughly adjust the pressure, and then a small reciprocating cylinder is used to fine-tune the pressure.

[0010] Furthermore, the pipeline leakage rate Q is used to calculate the speed of the small reciprocating cylinder, and the pressure of the small reciprocating cylinder is precisely controlled to be fine-tuned until the pressure setting value is reached, thereby completing the entire static pressure detection process.

[0011] The technical solution of the embodiment of the present invention has at least the following advantages and beneficial effects:

[0012] The present invention uses the above technical means to achieve the purpose of calibrating the pressure of a ventilator tester by generating a stable static pressure in the device, and the generated static pressure is stable within the range of ±1Pa; the device that generates the static pressure is shared with the flow parameter calibration module, and no independent static pressure generating device is required. The invention improves the integration of the calibration device, reduces costs, and reduces the usage area. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0014] Figure 1 It is a schematic diagram of the connection of the pressure generating device in the present invention;

[0015] Figure 2 It is a control flow chart in the present invention;

[0016] Markings in the figure: 1-industrial computer, 2-controller, 3-small reciprocating cylinder, 4-large reciprocating cylinder, 5-first intake valve, 6-first exhaust valve, 7-second intake valve, 8-second exhaust valve, 9-digital pressure gauge, 10-first quick-release connector, 11-measured instrument, 12-second quick-release connector, 13-third exhaust valve, 14-main pipeline. DETAILED DESCRIPTION

[0017] Please refer to Figure 1 , a method for generating static pressure in a ventilator tester calibration device, the calibration device includes a control module and a pressure parameter calibration module, the control module includes an industrial computer 1 and a controller 2; the pressure parameter calibration module includes a large reciprocating cylinder 4, a small reciprocating cylinder 3, a solenoid valve, and a digital pressure gauge 9; the industrial computer is connected to the controller 2, the controller 2 is electrically connected to the large reciprocating cylinder 4 and the small reciprocating cylinder 3, the controller 2 is electrically connected to the solenoid valve, the controller 2 is electrically connected to the digital pressure gauge 9, and the digital pressure gauge 9 is installed on the main pipeline 14; the main pipeline 14 is connected to the instrument under test 11 through a first quick-release connector 10, and the instrument under test 11 is then connected to a second quick-release connector 12 and connected to a third exhaust valve 13 through other pipelines, and the controller 2 controls the solenoid valve to open and close. The solenoid valve includes a first intake valve 5, a first exhaust valve 6, a second intake valve 7, a second exhaust valve 8, and a third exhaust valve 13, see Figure 1, the controller 2 opens the first intake valve 5 and closes the first exhaust valve 6, so that the small reciprocating cylinder 3 can perform an intake operation; the controller 2 closes the first intake valve 5 and opens the first exhaust valve 6, so that the small reciprocating cylinder 3 can perform an exhaust operation, and the gas enters the main pipeline 14. The controller 2 opens the second intake valve 7 and closes the second exhaust valve 8, so that the large reciprocating cylinder 4 can perform an intake operation; the controller 2 closes the second intake valve 7 and opens the second exhaust valve 8, so that the large reciprocating cylinder 4 can perform an exhaust operation, and the gas enters the main pipeline 14.

[0018] The industrial computer 1 is equipped with calibration software, which sends calibration parameters to the controller 2 .

[0019] Reference Figure 1 and Figure 2 , the controller 2 controls the reciprocating motion of the reciprocating cylinder to generate pressure in the main pipeline 14, the large reciprocating cylinder 4 roughly adjusts the pressure, and the small reciprocating cylinder 3 finely adjusts the pressure.

[0020] The controller 2 measures the pressure in the main pipeline 14 through the digital pressure gauge 9, calculates the running speed of the reciprocating cylinder, and controls the operation of the reciprocating cylinder to supplement and extract pressure.

[0021] Furthermore, the calibration pressure is divided into a pressure increase and a pressure decrease process. Generally, one to two pressure increase pre-pressure tests should be performed before calibration to ensure that the instrument 11 under test is reliably connected through the first quick-release connector 10 .

[0022] Furthermore, in the boost pre-pressure test, the industrial computer 1 sends the boost pre-pressure value to the controller 2. After receiving the command, the controller 2 opens the second exhaust valve 8, starts the operation of the large reciprocating cylinder 4, and injects pressure into the main pipeline. The controller 2 measures the pressure of the digital pressure gauge 9 and compares it with the boost pre-pressure value. When the boost pre-pressure value is reached, the operation of the large reciprocating cylinder 4 is stopped immediately.

[0023] Furthermore, when the reciprocating cylinder stops running, the pressure in the main pipeline changes from dynamic pressure to static pressure. There is a stabilization time from dynamic to static, and the specific time needs to be determined according to factors such as the type, diameter, length, and material of the pipeline. In an ideal sealed pipeline, the calculation formula for the stabilization time is (1):

[0024] T= (P0-P l ) × V × K (1)

[0025] T: voltage stabilization time, in (s);

[0026] K: Proportional coefficient. Because there are different types of pipelines on the pipeline, the value is generally between 60-120. The actual value is determined by calibration;

[0027] V: The sum of the geometric volumes of the small reciprocating cylinder, the large reciprocating cylinder and the pipeline, in cubic meters (m 3 );

[0028] P0: current pressure setting value, in kilopascals (kPa);

[0029] P l : The last pressure setting value, in kPa. For the first pressure increase, the value is 0.

[0030] Further, after waiting for the pressure stabilization time T, the pressure P is recorded. T , record the pressure P at intervals of t t , calculate the pipeline leakage rate Q, formula (2):

[0031]

[0032] Q: Pipeline leakage rate, in kilopascal cubic meters per second (kPa·m 3 / s);

[0033] P T : Stabilization time Tpressure, in kilopascals (kPa);

[0034] P t : interval time t pressure, in kilopascals (kPa);

[0035] V: The geometric volume of the current small reciprocating cylinder, the current large reciprocating cylinder, and the pipeline, in cubic meters (m 3 );

[0036] Of course, the pipeline leakage and deflation rate Q can also be obtained by other conventional methods, such as a device specifically used to detect the pipeline leakage and deflation rate or other conventional pipeline leakage and deflation rate calculation formulas.

[0037] Furthermore, whether the connection of the equipment under inspection is reliable is determined based on the calculated pipeline leakage and deflation rate Q.

[0038] Furthermore, after the pipeline leakage and degassing rate Q meets the requirement, the controller 2 opens the third exhaust valve 13 to exhaust the pressure in the main pipeline 14 until it reaches 0, and then closes the third exhaust valve 13 .

[0039] Furthermore, during static pressure calibration, the pressure increase and pressure reduction in the calibration is a continuous process, first the pressure is increased, and then the pressure is reduced.

[0040] Further, in the boost calibration, the forward stroke of the large reciprocating cylinder 4 is used as a rough adjustment pressure to charge the main pipeline until it approaches the set pressure value, and the forward stroke of the small reciprocating cylinder 3 fine-tunes the pressure in the main pipeline 14 until it reaches the set pressure value; specifically, the industrial computer 1 sends the boost calibration point value to the controller 2, and the controller 2 opens the second exhaust valve 8 after receiving the instruction. To prevent pressure shock, the large reciprocating cylinder 4 runs at a low speed to inject pressure into the main pipeline. The controller 2 measures the pressure of the digital pressure gauge 9 and compares it with the boost calibration point value. To prevent overpressure, the large reciprocating cylinder 4 is stopped immediately when it approaches the boost value. The approaching condition can be the approach judged by a person skilled in the art.

[0041] Furthermore, after the large reciprocating cylinder 4 stops running, the pressure at the measuring point drops rapidly. After waiting for the pressure stabilization time T, the pressure gradually stabilizes, and then the small reciprocating cylinder 3 is started to fine-tune the pressure in the forward stroke so that the pressure in the main pipeline 14 reaches the set pressure value.

[0042] Furthermore, in order to accurately regulate the pressure and avoid overpressure and punching, the running speed of the small reciprocating cylinder 3 is crucial. The running speed is proportional to the pipeline leakage rate, formula (3):

[0043] v1= (Q +P0-P i ) × K1 (3)

[0044] v1: running speed of small reciprocating cylinder mm / s;

[0045] Q: Pipeline leakage rate, in kilopascal cubic meters per second (kPa·m 3 / s);

[0046] P0: set pressure value;

[0047] P i : Current pressure value;

[0048] K1: coefficient, the value is determined by fitting the formula through the measured data;

[0049] Furthermore, the greater the leakage rate, the faster the small reciprocating cylinder 3 runs. When the pressure replenishing speed of the small reciprocating cylinder 3 into the main pipeline 14 reaches a balance with the leakage rate Q, the pressure in the main pipeline 14 reaches a balance.

[0050] Furthermore, before the small reciprocating cylinder 3 is started, the current pressure in the main pipeline 14 is lower than the set pressure value, and the pressure replenishing speed of the small reciprocating cylinder 3 is greater than the leakage speed, which will introduce a pressure difference relationship. When the current pressure in the main pipeline is close to the set pressure value, the running speed of the small reciprocating cylinder 3 gradually slows down. When the pressure difference is 0, the pressure replenishing speed of the small reciprocating cylinder 3 into the main pipeline 14 reaches a balance with the leakage rate, and the pressure in the main pipeline 14 reaches a balance.

[0051] Further, the controller 2 ends the voltage boost and voltage regulation, and feeds back a voltage regulation end instruction.

[0052] Furthermore, the pressure reduction calibration is performed, the large reciprocating cylinder 4 roughly adjusts the pressure during the reverse stroke, and the small reciprocating cylinder 3 finely adjusts the pressure. The industrial computer sends the pressure reduction calibration point value to the controller 2. After receiving the command, the controller 2 opens the second exhaust valve 8. To prevent pressure shock, the large reciprocating cylinder 4 runs in the reverse stroke at a low speed to expand the volume to reduce the pressure in the main pipeline 14. The controller 2 measures the pressure of the digital pressure gauge 9 and compares it with the pressure reduction calibration point value. To prevent under-pressure, the operation of the large reciprocating cylinder 4 is stopped immediately when it is close to the pressure reduction value.

[0053] Furthermore, the large reciprocating cylinder 4 relieves the pressure in the main pipeline 14. When it stops running, the pressure at the measuring point gradually rises, and after the pressure stabilization time T, the small reciprocating cylinder 3 is started to fine-tune the pressure in the reverse stroke, so that the pressure in the main pipeline 14 reaches the set pressure value.

[0054] Furthermore, the small reciprocating cylinder 3 is started to fine-tune the pressure reduction in the reverse stroke, so that the pressure in the main pipeline 14 is reduced to the set pressure value. The reverse running speed is calculated by formula (4):

[0055] v2 = (P0-P i ) × K2 (4)

[0056] v2: reverse running speed of small reciprocating cylinder mm / s;

[0057] K2: coefficient, the value is determined by fitting the formula through the measured data;

[0058] P0: set pressure value;

[0059] P i : Current pressure value;

[0060] Furthermore, P i The pressure is greater than P0 and is calculated as a negative number, that is, the small reciprocating cylinder runs in the reverse direction, gradually reducing the pressure in the main pipeline 14. When it is closer to the setting, the small reciprocating cylinder stops running; wait for the pressure in the main pipeline 14 to stabilize.

[0061] Furthermore, due to air leakage in the pipeline, the pressure in the main pipeline 14 gradually drops to a set pressure value or below the set pressure value. When the set pressure value is reached or below the set pressure value, the small reciprocating cylinder is started to move forward to replenish the pressure in the main pipeline 14. The running speed of the small reciprocating cylinder is determined by the air leakage rate, which is substituted into formula (3) to calculate the pressure replenishment speed.

[0062] Further, the controller 2 ends the voltage reduction and voltage regulation, and feeds back a voltage regulation end instruction.

[0063] Furthermore, through the above control process, the static pressure is within the range of the set pressure value ±1Pa. The formula involves the K value, which needs to be calibrated.

Claims

1. A method for generating static pressure in a ventilator tester calibration device, characterized in that: The static pressure calibration process includes a pressure adjustment method, wherein the pressure is roughly adjusted by a large reciprocating cylinder (4), and then the pressure is finely adjusted by a small reciprocating cylinder (3) until a set pressure value is reached.

2. A method for generating static pressure in a breathing machine tester calibration device according to claim 1, characterized in that: The pressure regulation method further comprises: after the large reciprocating cylinder (4) has completed the rough pressure adjustment and stopped running, the pressure at the measuring point will change rapidly, and after waiting for the pressure stabilization time T, the pressure will gradually stabilize, and then the small reciprocating cylinder (3) will be started to finely adjust the pressure, so that the pressure in the main pipeline (14) reaches the set pressure value; The calculation formula of the voltage stabilization time T is (1): T= (P0-P l ) ×V×K (1) T: voltage stabilization time, in (s); K: comprehensive coefficient. Because there are different types of pipelines on the pipeline, the value is generally between 60-120. The actual value is determined by calibration; V: The sum of the geometric volumes of the small reciprocating cylinder, the large reciprocating cylinder and the pipeline, in cubic meters (m 3 ); P0: current pressure setting value, in kilopascals (kPa); P l : The last pressure setting value, in kilopascals (kPa). For the first pressure increase, the value is 0.

3. A method for generating static pressure in a breathing machine tester calibration device according to claim 2, characterized in that: The static pressure calibration process includes a pressure boosting process and a pressure reducing process. During the calibration process, the pressure boosting process and the pressure reducing process are a continuous process, and the pressure boosting process is carried out first, and then the pressure reducing process is carried out; the pressure regulating method is used in both the pressure boosting process and the pressure reducing process.

4. A method for generating static pressure in a breathing machine tester calibration device according to claim 3, characterized in that: In the pressure boosting process, the pressure regulating method is specifically as follows: the forward stroke of the large reciprocating cylinder (4) is used as a coarse adjustment pressure to charge the main pipeline (14) until it approaches the set pressure value, and the forward stroke of the small reciprocating cylinder (3) finely adjusts the pressure in the main pipeline (14) until it reaches the set pressure value; specifically, the industrial control computer (1) sends the pressure boosting calibration point value to the controller (2), and the controller (2) opens the second exhaust valve (8) after receiving the instruction. To prevent pressure shock, the large reciprocating cylinder (4) runs at a low speed to inject pressure into the main pipeline (14), and the controller (2) measures the pressure of the digital pressure gauge (9) and compares it with the pressure boosting calibration point value. To prevent overpressure, the operation of the large reciprocating cylinder (4) is immediately stopped when it approaches the pressure boosting value; After the large reciprocating cylinder (4) stops running, the pressure at the measuring point drops rapidly. After waiting for the pressure stabilization time T, the pressure gradually stabilizes. Then, the small reciprocating cylinder (3) is started to fine-tune the pressure in the forward stroke so that the pressure in the main pipeline (14) reaches the set pressure value.

5. A method for generating static pressure in a breathing machine tester calibration device according to claim 4, characterized in that: Furthermore, during the forward stroke of the small reciprocating cylinder (3), the running speed of the small reciprocating cylinder (3) is controlled. The running speed of the small reciprocating cylinder (3) is proportional to the pipeline leakage rate Q. Formula (3): v1= (Q +P0-P i ) × K1 (3) v1: running speed of small reciprocating cylinder mm / s; Q: Pipeline leakage rate, in kilopascal cubic meters per second (kPa·m 3 / s); P0: set pressure value; P i : Current pressure value; K1: coefficient, the value is determined by fitting the formula through the measured data; The greater the pipeline air leakage and release rate Q, the faster the running speed of the small reciprocating cylinder (3) becomes. When the pressure replenishing speed of the small reciprocating cylinder (3) into the main pipeline (14) reaches a balance with the pipeline air leakage and release rate Q, the pressure in the main pipeline (14) reaches a balance and stabilizes at a set pressure value.

6. A method for generating static pressure in a breathing machine tester calibration device according to claim 5, characterized in that: Furthermore, in the process of controlling the running speed of the small reciprocating cylinder (3), before the small reciprocating cylinder (3) is started, the current pressure of the main pipeline (14) is lower than the set pressure value, and the pressure replenishing speed of the small reciprocating cylinder (3) is greater than the pipeline leakage and release rate Q. When the current pressure of the main pipeline (14) approaches the set pressure value P0, the running speed of the small reciprocating cylinder (3) gradually slows down, and when the pressure difference is 0, the pressure replenishing speed of the small reciprocating cylinder (3) into the main pipeline (14) reaches a balance with the pipeline leakage and release rate Q, and the pressure in the main pipeline (14) reaches a balance and stabilizes at the set pressure value.

7. A method for generating static pressure in a breathing machine tester calibration device according to any one of claims 3 to 6, characterized in that: In the pressure reduction process, the pressure regulation method is specifically as follows: the large reciprocating cylinder (4) uses a reverse stroke as a rough adjustment pressure to reduce the pressure in the main pipeline (14); when the pressure approaches the set pressure value, the small reciprocating cylinder (3) uses a reverse stroke to fine-tune the pressure in the main pipeline (14) until the pressure approaches or reaches the set pressure value, and finally reaches the set pressure value; specifically, the industrial control computer (1) sends the pressure reduction calibration point value to the controller (2); after receiving the instruction, the controller (2) opens the second exhaust valve (8); to prevent pressure shock, the large reciprocating cylinder (4) runs at a low speed to unload the pressure in the main pipeline (14); the controller (2) measures the pressure of the digital pressure gauge (9) and compares it with the pressure reduction calibration point value; to prevent underpressure, the large reciprocating cylinder stops running immediately when the pressure approaches the pressure reduction value; After the large reciprocating cylinder (4) stops running, the pressure at the measuring point gradually rises. After waiting for the pressure stabilization time T, the pressure gradually stabilizes. Then, the small reciprocating cylinder (3) is started to fine-tune the pressure in the reverse stroke so that the pressure in the main pipeline (14) is closer to or reaches the set pressure value, and the pressure is waited for to stabilize again.

8. A method for generating static pressure in a breathing machine tester calibration device according to claim 7, characterized in that: Furthermore, during the reverse stroke of the small reciprocating cylinder (3), the running speed of the small reciprocating cylinder (3) is controlled. The running speed formula (4) of the small reciprocating cylinder (3) is: <h2 style=";text-align:left;direction:ltr">v2 = (P0-P<h2 style=";text-align:left;direction:ltr"> i <h2 style=";text-align:left;direction:ltr"> ) × K2 (4) v2: reverse running speed of small reciprocating cylinder mm / s; K2: coefficient, the value is determined by fitting the formula through the measured data; P0: set pressure value; P i : Current pressure value; Where P i When the pressure is greater than P0, it is calculated as a negative number, that is, the small reciprocating cylinder (3) runs in the reverse direction, gradually reducing the pressure in the main pipeline (14). When it is closer to the set pressure value, the small reciprocating cylinder (3) stops running and waits for the pressure in the main pipeline (14) to stabilize. When there is a gas leakage in the main pipeline (14), the pressure will gradually drop to the set pressure value or lower than the set pressure value. When the pressure reaches the set pressure value or lower than the set pressure value, the small reciprocating cylinder (3) starts the forward stroke to replenish the pressure in the main pipeline (14). The running speed of the small reciprocating cylinder (3) is determined by the pipeline leakage and release rate Q, and is substituted into formula (3) to calculate the running speed of the pressure replenishment, which is equal to v1. v1= (Q +P0-P i ) × K1 (3) v1: running speed of small reciprocating cylinder mm / s; Q: Pipeline leakage rate, in kilopascal cubic meters per second (kPa·m 3 / s); P0: set pressure value; P i : Current pressure value; K1: Coefficient, the value is determined by fitting the formula through the measured data.

9. A method for generating static pressure in a breathing machine tester calibration device according to any one of claims 2 to 8, characterized in that: Before using the pressure regulating method, a boost pre-pressure test is first carried out. The boost pre-pressure test industrial control computer sends a boost pre-pressure value to the controller. After receiving the command, the controller opens the second exhaust valve 8, starts the large reciprocating cylinder to inject pressure into the main pipeline (14). The controller measures the pressure of the digital pressure gauge and compares it with the boost pre-pressure value. When the boost pre-pressure value is reached, the large reciprocating cylinder is immediately stopped. After stopping the large reciprocating cylinder, the pipeline leakage rate Q is calculated; after waiting for the pressure stabilization time T, the pressure P is recorded. T , record the pressure P at intervals of t t , calculate the pipeline leakage rate Q, formula (2): Q: Pipeline leakage rate, in kilopascal cubic meters per second (kPa·m 3 / s); P T : Stabilization time Tpressure, in kilopascals (kPa); P t : interval time t pressure, in kilopascals (kPa); V: The geometric volume of the current small reciprocating cylinder, the current large reciprocating cylinder, and the pipeline, in cubic meters (m 3 ); Whether the equipment under inspection is reliably connected is determined by calculating the pipeline leakage and deflation rate Q.

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