A sinusoidal breathing apparatus for testing aircraft oxygen masks

Abstract

The present application relates to a kind of sine formula breathing device for aircraft oxygen mask test, belong to breathing device technical field.The device includes the driving unit for the power of piston cylinder piston movement, piston cylinder simulating human lung, gas pipeline connecting piston cylinder and first three-way valve, suction pipeline and exhalation pipeline installed between first three-way valve and second three-way valve, mass flow meter arranged on suction pipeline, heating and humidifying unit arranged on exhalation pipeline, pressure temperature table for monitoring ambient pressure and temperature, control unit electrically connected with pressure temperature table, mass flow meter, first three-way valve, second three-way valve and servo cylinder respectively.The device can control the tidal volume of simulated human sine formula breathing, respiratory volume, exhalation temperature and exhalation humidity, also can correct the motion state of driving unit to change tidal volume and respiratory volume, simple operation, high precision, applicable to different pressure environment.

Description

TECHNICAL FIELD

[0001] The present application relates to a sine type breathing device for aircraft oxygen mask test, belonging to the technical field of breathing device. BACKGROUND

[0002] The aircraft oxygen mask is arranged in the cabin of the aircraft, and can provide emergency oxygen supply for the passengers and crew in the cabin when an emergency occurs during high-altitude flight, maintain the oxygen partial pressure of the passengers, and is an essential emergency lifesaving device. According to the SAE AS8025 standard, the oxygen supply performance test of the aircraft oxygen mask needs to use a breathing device to simulate the sine type breathing state of the human body under different cabin altitude pressures, and the tidal volume of the breathing device has 0.7L-BTPS, 1.1L-BTPS, the breathing volume has 15LPM-BTPS, 30LPM-BTPS several different modes.

[0003] The disclosed sine type breathing device is mostly a medical breathing machine and a breathing machine for breathing equipment test. The medical breathing machine has a complex structure and is expensive, and since the medical breathing machine is generally used under atmospheric environmental pressure, the influence of the breathing gaseous state is not considered in the design of the medical breathing machine, and the actual tidal volume cannot be monitored and corrected, the precision is not high, and the tidal volume and the breathing volume cannot meet the requirements of the aircraft oxygen mask test. SUMMARY

[0004] In view of the deficiencies of the medical breathing machine in the aircraft oxygen mask test at present, the present application provides a sine type breathing device for aircraft oxygen mask test, which can correct the motion of the servo cylinder according to the actual generated tidal volume, thereby changing the tidal volume and the breathing volume, simple operation, high precision, good stability, can be used under different pressure environments, and meets the requirements of the aircraft oxygen mask test.

[0005] The purpose of the present application is achieved by the following technical solutions.

[0006] A sine type breathing device for aircraft oxygen mask test, comprising a driving unit, a piston cylinder, a gas pipeline, a first three-way valve, an exhalation pipeline, a heating and humidifying unit, an inhalation pipeline, a mass flow meter, a second three-way valve, a pressure and temperature table, and a control unit.

[0007] The driving unit is used to provide power for the piston motion of the piston cylinder; the driving unit is preferably a servo cylinder, the push rod of the servo cylinder is connected with the piston of the piston cylinder, and the linear reciprocating motion of the push rod drives the piston to move;

[0008] The cylinder body and the piston of the piston cylinder form a cavity for simulating human lungs, and the working process is as follows: when the push rod of the servo cylinder pushes the piston of the piston cylinder, the volume of the cavity decreases, simulating the human exhalation state; when the push rod of the servo cylinder pulls the piston of the piston cylinder, the volume of the cavity increases, simulating the human inhalation state; an interface connected with the gas pipeline is arranged on the cavity;

[0009] One interface of the first three-way valve is connected with the interface on the piston cylinder through the gas pipeline, and the other two interfaces are respectively connected with one end of the inhalation pipeline and one end of the exhalation pipeline one by one.

[0010] The other two interfaces of the second three-way valve are respectively connected with the other end of the exhalation pipeline and the other end of the inhalation pipeline one by one, and the other interface is used for communicating with the aircraft mask to be tested to provide a sinusoidal exhalation gas flow.

[0011] The mass flow meter is arranged on the inhalation pipeline for monitoring the flow of gas in the inhalation pipeline.

[0012] The heating and humidifying unit is arranged on the exhalation pipeline for heating and humidifying the gas in the exhalation pipeline to the required temperature and humidity.

[0013] The pressure and temperature meter is used for monitoring the ambient pressure and temperature.

[0014] The control unit is electrically connected with the pressure and temperature meter, the mass flow meter, the first three-way valve, the second three-way valve and the servo cylinder, and is used for adjusting and controlling the tidal volume, the respiratory volume, the exhalation temperature and the exhalation humidity of the simulated sinusoidal human respiration, and the specific control principle is as follows: the control unit changes the cavity volume change amount of the piston cylinder by controlling the stroke of the servo cylinder, thereby realizing the requirement of adjusting the tidal volume of the simulated respiration in the range of 0.3-1.5L-BTPS; by controlling the number of linear reciprocating movements of the servo cylinder per minute and the stroke of the servo cylinder per single movement, the requirement of adjusting the respiratory volume per minute in the range of 5-100LPM-BTPS is realized; by controlling the push and stretch speed of the servo cylinder to change in a sinusoidal function, the requirement of simulating the sinusoidal human respiration is realized; according to the information fed back by the mass flow meter, the control unit calculates the single inhalation gas flow in the inhalation pipeline and the total inhalation gas flow in the inhalation pipeline per minute through logical operation, and then corrects the movement stroke of the servo cylinder according to the calculation result; the control unit controls the heating and humidifying unit to control the exhalation temperature and humidity in the required range.

[0015] Further, considering the human physiological dead space, the sum of the volumes of the exhalation pipeline and the gas pipeline is 90-100mL, and the sum of the volumes of the inhalation pipeline and the gas pipeline is 90-100mL.

[0016] Further, the first three-way valve and the second three-way valve are both two-position three-way electromagnetic valves; when in the expiration state, the control unit controls the first three-way valve and the second three-way valve to conduct the expiration pipeline; when in the inspiration state, the control unit controls the first three-way valve and the second three-way valve to conduct the inspiration pipeline.

[0017] The principle of correcting the stroke and speed of the servo cylinder during operation of the sinusoidal breathing device is as follows:

[0018] According to the need, the tidal volume value in L-BTPS, the breathing frequency (f), the expiration temperature (generally 37℃) and the expiration humidity are input into the control unit, wherein the expiration temperature and the expiration humidity do not participate in the breathing volume correction, but only participate in the simulation of the human body expiration state; the control unit automatically calculates the corresponding tidal volume value in L-ATPD according to the pressure information (P ATPD ) and the temperature information (T ATPD ) fed back by the pressure temperature table, as shown in formula (1):

[0019]

[0020] In formula (1), P ATPD is the environmental pressure, A ATPD is the tidal volume under the environmental temperature, the environmental pressure and the dry environmental condition, T ATPD is the environmental temperature, P BTPS is the pressure under the human body temperature environment, A BTPS is the tidal volume under the human body temperature and pressure and the humid environmental condition, and T BTPS is the human body temperature.

[0021] The breathing volume value (H) is calculated according to formula (2):

[0022] H=fA BTPS (2)

[0023] The movement stroke S of the servo cylinder is preliminarily calculated according to formula (3) by using the cavity diameter D of the piston cylinder and the input tidal volume value:

[0024]

[0025] The movement function V of the servo cylinder is calculated by using formula (4):

[0026]

[0027] In formula (4), t is time;

[0028] The control unit sends the movement instruction to the servo cylinder, and the servo cylinder starts the linear reciprocating movement with the speed function V and the stroke S.

[0029] The control unit records the actual tidal volume accumulated by the mass flow meter in a certain time (such as 40-120s) and takes the average value A according to the feedback flow information of the mass flow meter 平均 The stroke and speed of the servo cylinder are respectively corrected according to formula (5)-(6):

[0030]

[0031]

[0032] Wherein, S 修正 is the corrected movement stroke of the servo cylinder, V 修正 is the speed function of the corrected servo cylinder;

[0033] The control unit sends a movement instruction to the servo cylinder, and the servo cylinder starts linear reciprocating motion with the speed function V 修正 and the stroke S 修正 .

[0034] Advantages:

[0035] (1) The present application can change the tidal volume and respiratory volume by changing the movement of the servo cylinder, and meets the demand of sinusoidal breathing, has the characteristics of simple structure and easy operation.

[0036] (2) The present application sets a mass flow meter on the inhalation pipeline, effectively avoids the interference of exhalation temperature and humidity on the mass flow meter, and can more accurately monitor the actual generated tidal volume in the pipeline; at the same time, the movement equation of the servo cylinder is corrected according to the monitoring result, has the characteristics of high precision and good stability.

[0037] (3) The sinusoidal breathing device described in the present application can be used in different pressure environments, has wide application range, strong applicability, and meets the requirements of aircraft oxygen mask test. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 It is a structure schematic view of the sinusoidal breathing device described in the embodiment.

[0039] Wherein, 1-servo cylinder, 2-piston cylinder, 3-first three-way valve, 4-exhalation pipeline, 5-heating and humidifying unit, 6-second three-way valve, 7-mass flow meter, 8-inhalation pipeline, 9-pressure and temperature table, 10-control unit, 11-gas pipeline. DETAILED DESCRIPTION

[0040] The application will be further described below in conjunction with the accompanying drawings and specific embodiments, wherein the methods are all conventional methods unless otherwise specified, and the raw materials can be obtained from public commercial channels unless otherwise specified. In addition, in the description of the application, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the application.

[0041] Embodiment 1

[0042] A sine type breathing device for testing an aircraft oxygen mask comprises a driving unit, a piston cylinder 2, a gas pipeline 11, a first three-way valve 3, an exhalation pipeline 4, a heating and humidifying unit 5, an inhalation pipeline 8, a mass flow meter 7, a second three-way valve 6, a pressure and temperature meter 9, and a control unit 10, as shown in Figure 1 ;

[0043] The driving unit is a servo cylinder 1, which is used to provide power for the piston movement of the piston cylinder 2; wherein the push rod of the servo cylinder 1 is connected with the piston of the piston cylinder 2, and the linear reciprocating movement of the push rod drives the piston to move;

[0044] The cylinder body of the piston cylinder 2 forms a cavity with the piston, which is used to simulate the human lung, and the specific working process is as follows: when the push rod of the servo cylinder 1 pushes the piston of the piston cylinder 2, the volume of the cavity decreases, simulating the human exhalation state; when the push rod of the servo cylinder 1 stretches the piston of the piston cylinder 2, the volume of the cavity increases, simulating the human inhalation state; an interface connected with the gas pipeline 11 is arranged on the cavity;

[0045] Both the first three-way valve 3 and the second three-way valve 6 are two-position three-way electromagnetic valves; one interface of the first three-way valve 3 is connected with the interface on the piston cylinder 2 through the gas pipeline 11, and the other two interfaces are respectively and correspondingly connected with one end of the inhalation pipeline 8 and one end of the exhalation pipeline 4; two interfaces of the second three-way valve 6 are respectively and correspondingly connected with the other end of the exhalation pipeline 4 and the other end of the inhalation pipeline 8, and the other interface is connected with the aircraft mask to be tested through the interface on the sealing tool or the human head model, wherein the aircraft mask to be tested is worn on the sealing tool or the human head model; when in the exhalation state, the control unit 10 controls the first three-way valve 3 and the second three-way valve 6 to conduct the exhalation pipeline 4; when in the inhalation state, the control unit 10 controls the first three-way valve 3 and the second three-way valve 6 to conduct the inhalation pipeline 8.

[0046] The mass flow meter 7 is arranged on the inspiratory pipeline 8 for monitoring the flow of gas in the inspiratory pipeline 8;

[0047] The heating and humidifying unit 5 is arranged on the expiratory pipeline 4 for heating and humidifying the gas in the expiratory pipeline 4 to the required temperature and humidity;

[0048] Considering the physiological dead space of human body, the sum of the volume of the expiratory pipeline 4 and the gas pipeline 11 is 100 mL, and the sum of the volume of the inspiratory pipeline 8 and the gas pipeline 11 is 100 mL;

[0049] The pressure and temperature meter 9 is used for monitoring the ambient pressure and temperature, and the pressure and temperature values tested can be displayed on the man-machine interface of the control unit 10;

[0050] The control unit 10 is electrically connected with the pressure and temperature meter 9, the mass flow meter 7, the first three-way valve 3, the second three-way valve 6 and the servo cylinder 1 respectively (as shown by the dashed line), for regulating and controlling the tidal volume, respiratory volume, expiratory temperature and expiratory humidity of the simulated human sinusoidal breathing; the control unit 10 also has a man-machine interface for inputting corresponding parameters and displaying corresponding test results; Figure 1

[0051] The specific principle of the control unit 10 for regulating and controlling the tidal volume, respiratory volume, expiratory temperature and expiratory humidity of the simulated human sinusoidal breathing is as follows: the control unit 10 changes the stroke of the servo cylinder 1 to change the cavity volume of the piston cylinder 2, thereby realizing the requirement of the simulated breathing tidal volume adjustment range of 0.3-1.5 L-BTPS; the control unit 10 controls the linear reciprocating motion frequency of the servo cylinder 1 per minute and the stroke of the servo cylinder 1 per single motion, thereby realizing the requirement of the respiratory volume adjustment range of 5-100 LPM-BTPS per minute; the control unit 10 controls the pushing and stretching speed of the servo cylinder 1 to change in a sinusoidal function, thereby realizing the requirement of the simulated human sinusoidal breathing; according to the feedback information of the mass flow meter 7, the control unit 10 calculates the single inspiration gas flow in the inspiratory pipeline 8 and the total inspiration gas flow in the inspiratory pipeline 8 per minute through logical operation, and then corrects the motion stroke of the servo cylinder 1 according to the calculation result; the control unit 10 controls the heating and humidifying unit 5 to control the expiratory temperature and humidity within the required range.

[0052] The specific working process of the sinusoidal breathing device is as follows:

[0053] According to the requirement, the tidal volume value 0.7 L-BTPS, the respiratory frequency (f) 22 times, the expiratory temperature 37℃ and the expiratory humidity 75% are inputted in the control unit 10 respectively, the pressure value (P ATPD ) 101.3 kPa and the temperature value (T ATPD ​)21℃, the control unit automatically calculates the corresponding tidal volume of 0.62 L-ATPD and the corresponding respiratory volume (H) of 15.4 LPM-BTPS according to formula (1) and formula (2):

[0054]

[0055] H = fA BTPs (2)

[0056] In the formula, P ATPD is the ambient pressure, A ATPD is the tidal volume under the ambient temperature, ambient pressure and dry environmental conditions, T ATPD is the ambient temperature, P BTPS is the pressure under the human body temperature environment, A BTPS is the tidal volume under the human body temperature and pressure and humid environmental conditions, T BTPS is the human body temperature;

[0057] According to the cavity diameter (D) of 200 mm of the piston cylinder 2 and the input tidal volume value, the movement stroke (S) of 19.75 mm of the servo cylinder 1 is preliminarily calculated by formula (3):

[0058]

[0059] The movement function V = 22.74sin(0.73πt) of the servo cylinder 1 is calculated by formula (4):

[0060]

[0061] According to the calculation result, the control unit 10 sends the corresponding movement instruction to the servo cylinder 1, and the servo cylinder 1 starts the linear reciprocating motion with the above preliminarily calculated stroke (S) of 19.75 mm and the speed function V = 22.74sin(0.73πt); the control unit 10 reads the flow information feedback by the mass flow meter 7 in real time, and can display the inhalation waveform diagram on the man-machine interaction interface, and through the calculation of the average value of the actual tidal volume in 1 minute (A 平均 )0.55 L-ATPD, the stroke and speed of the servo cylinder 1 are respectively corrected according to formula (5)-(6);

[0062]

[0063]

[0064] According to the corrected calculation result, the control unit 10 sends the corresponding movement instruction to the servo cylinder 1, and the servo cylinder 1 moves with the corrected stroke (S 修正 ) of 22.26 mm and the speed function V 修正= 25.63 sin(0.73πt) to move linearly back and forth.

[0065] Example 2

[0066] Based on the sinusoidal breathing device described in Example 1, the tidal volume value 1.1L-BTPS, breathing frequency (f) 27 times, exhalation temperature 37°C and exhalation humidity 75% are input into the control unit 10 as needed, the pressure value (P ATPD ) 18.7kPa and the temperature value (T ATPD ) 21°C fed back by the pressure temperature table 9, and the control unit automatically calculates the corresponding tidal volume 0.69L-ATPD and the corresponding breathing volume (H) 29.7LPM-BTPS according to formula (1) and formula (2):

[0067]

[0068] H = fA BTPs (2)

[0069] In the formula, P ATPD is the ambient pressure, A ATPD is the tidal volume under the conditions of ambient temperature, ambient pressure and dry environment, T ATPD is the ambient temperature, P BTPS is the pressure under the conditions of human body temperature environment, A BTPS is the tidal volume under the conditions of human body temperature and pressure and humid environment, and T BTPS is the human body temperature.

[0070] According to the cavity diameter (D) of the piston cylinder 2 200mm and the input tidal volume value, the motion stroke (S) of the servo cylinder 1 is preliminarily calculated by formula (3) 22mm:

[0071]

[0072] The motion function V = 31.1 sin(0.9πt) of the servo cylinder 1 is calculated by formula (4):

[0073]

[0074] According to the calculation result, the control unit 10 sends the corresponding motion instruction to the servo cylinder 1, and the servo cylinder 1 starts linear reciprocating motion with the above preliminary calculated stroke (S) 22mm and speed function V = 31.1 sin(0.9πt); the control unit 10 reads the flow information fed back by the mass flow meter 7 in real time, and can display the inhalation waveform diagram on the man-machine interaction interface, and calculate the average value of the actual tidal volume in 1 minute (A 平均)0.59L-ATPD, the stroke and speed of the servo cylinder 1 are respectively corrected according to formulas (5) and (6);

[0075]

[0076]

[0077] According to the corrected calculation result, the control unit 10 sends a corresponding motion instruction to the servo cylinder 1, and correspondingly the servo cylinder 1 performs linear reciprocating motion with the corrected stroke (S 修正 )25.74mm and the speed function V 修正 =36.4sin(0.9πt).

[0078] To sum up, the above is only a preferred embodiment of the present application, and is not used to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A sinusoidal breathing device for testing aircraft oxygen masks, characterized in that: It includes a drive unit, piston cylinder, gas pipeline, first three-way valve, exhalation pipeline, heating and humidification unit, inhalation pipeline, mass flow meter, second three-way valve, pressure and temperature gauge, and control unit; The drive unit is used to provide power for the piston movement of the piston cylinder; the drive unit is a servo electric cylinder, the push rod of the servo electric cylinder is connected to the piston of the piston cylinder, and the piston is driven to move through the linear reciprocating motion of the push rod. The cylinder body and piston form a cavity to simulate the human lung; an interface is provided on the cavity. One port of the first three-way valve is connected to the port on the piston cylinder through the gas pipeline, and the other two ports are connected to one end of the inhalation pipeline and one end of the exhalation pipeline, respectively. The two ports of the second three-way valve are connected to the other end of the exhalation line and the other end of the inhalation line respectively, and the other port is used to connect to the aircraft mask to be tested. The mass flow meter is installed on the intake line to monitor the flow rate of the gas; The heating and humidifying unit is located on the exhalation line and is used to heat and humidify the gas to the required temperature and humidity. Pressure-temperature gauges are used to monitor ambient pressure and ambient temperature; The control unit is electrically connected to the pressure and temperature gauge, mass flow meter, first three-way valve, second three-way valve and servo electric cylinder respectively, and is used to regulate the tidal volume, respiratory volume, exhalation temperature and exhalation humidity of simulating human sinusoidal breathing. During operation, the sinusoidal breathing device corrects the stroke and speed of the servo electric cylinder as follows: As needed, the tidal volume, respiratory rate, expiratory temperature, and expiratory humidity in L-BTPS are input into the control unit respectively; the control unit automatically calculates the corresponding tidal volume in L-ATPD according to the pressure and temperature information fed back by the pressure and temperature gauge, as shown in formula (1): The respiratory volume value is calculated according to formula (2): H=fA BTPS (2) Based on the cavity diameter of the piston cylinder and the input tidal volume, the stroke S of the servo electric cylinder is initially calculated using formula (3): The motion function V of the servo electric cylinder is calculated using formula (4): The control unit sends motion commands to the servo cylinder, and the servo cylinder begins linear reciprocating motion with a speed function V and a stroke S. The control unit records the actual tidal volume accumulated by the mass flow meter over a certain period of time based on the flow information fed back by the mass flow meter and takes its average value A. 平均 The stroke and speed of the servo electric cylinder are corrected according to formulas (5) and (6): The control unit sends motion commands to the servo cylinder, which then moves at a speed function V. 修正 Itinerary S 修正 Begin straight-line reciprocating motion; Where f is the respiratory rate, H is the respiratory volume, D is the diameter of the piston cylinder cavity, t is the time, and P is the respiratory rate. ATPD Due to environmental pressures, A ATPD T represents the moisture content under ambient temperature, ambient pressure, and dry environmental conditions. ATPD For ambient temperature, P BTPS Pressure at human body temperature, A BTPS T represents the moisture content under human body temperature, pressure, and humid conditions. BTPS For human body temperature, S 修正 For the corrected motion stroke of the servo electric cylinder, V 修正 This is the corrected speed function for the servo electric cylinder.

2. The sinusoidal breathing device for testing an aircraft oxygen mask according to claim 1, characterized in that: The combined volume of the expiratory tubing and the gas tubing is 90–100 mL, and the combined volume of the inspiratory tubing and the gas tubing is 90–100 mL.

3. The sinusoidal breathing device for testing an aircraft oxygen mask according to claim 1, characterized in that: Both the first three-way valve and the second three-way valve are two-position three-way solenoid valves.

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