Environmental parameter compensation system for non-contact tonometer blow module

Abstract

The application discloses an environmental parameter compensation system for a non-contact tonometer blowing module, solves the problem that the blowing air pressure is affected by environmental air pressure, temperature and humidity, and improves the measurement accuracy and environmental adaptability of the non-contact tonometer. The technical scheme is as follows: the system comprises: a gas charging module for charging gas into a gas cylinder and providing gas source pressure; a gas cylinder module for receiving the charged gas, storing compressed gas, and providing a gas source for the blowing process; a cylinder gas pressure sensor for monitoring the gas pressure in the gas cylinder in real time; a high-speed electromagnetic valve for receiving valve opening and closing instructions and controlling the on-off of the gas from the gas cylinder to the nozzle; an air outlet module serving as an outlet for the gas ejection and affecting the speed and direction of the air flow; a dynamic air pressure sensor installed near the air outlet module or the nozzle, monitoring the dynamic air pressure at the nozzle, and used for real-time feedback of the air pressure change in the blowing process; and an environmental parameter sensor for detecting environmental parameters.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tonometer devices, and particularly relates to a system for environmental parameter compensation (such as air pressure compensation and temperature and humidity compensation) applied to a blowing module of a non-contact tonometer. BACKGROUND

[0002] The working principle of a non-contact tonometer is as follows: after the nozzle of the machine is aligned with the center of the cornea of the testee and a specific distance (usually 11 mm) is maintained, the device releases a stream of air to press the cornea into a flat plane in a predetermined area. At this time, by detecting the change of reflected light through a sensor, the tonometer converts the flattening force of the air flow into an intraocular pressure measurement value. The key to this measurement method is that the accuracy and consistency of the air pressure force acting on the test cornea must be very high each time to ensure the accuracy and stability of the detection result. In addition, in order to adapt to different use environments, the instrument also needs to have a wide environmental adaptability.

[0003] However, the existing blowing module of the non-contact tonometer has some problems in actual use. First, the traditional blowing module only blows according to the set pressure value and blows according to the set valve opening time, lacking a feedback system. This design leads to poor consistency of blowing, making it difficult to ensure the accuracy and stability of the air pressure force in each measurement. Second, the effective blowing pressure finally acting on the cornea will be affected by various environmental factors. For example, changes in environmental air pressure, especially the altitude of the place where the instrument is used, will have a significant impact on the effective blowing pressure. In high-altitude areas, the air pressure is low, which may cause insufficient effective blowing pressure; while in low-altitude areas, the air pressure is high, which may cause the effective blowing pressure to exceed the expected range.

[0004] In addition, changes in environmental temperature and humidity also have a great impact on the effective blowing pressure. Changes in temperature will affect the density and pressure of the gas, and changes in humidity will affect the flow characteristics of the air and the detection accuracy of the sensor. In a high-temperature and high-humidity environment, the flow resistance of the gas may increase, causing the effective blowing pressure to decrease; while in a low-temperature and low-humidity environment, the density of the gas may increase, causing the effective blowing pressure to increase. The combined effect of these environmental factors makes it difficult for the existing non-contact tonometer to maintain consistency and accuracy of measurement results in different environments.

[0005] In summary, the existing non-contact tonometer has obvious deficiencies in the design of the blowing module, causing the blowing air pressure to be affected by environmental air pressure (such as altitude in different use places), temperature, and humidity, and thus cannot meet the requirements of high precision, high stability, and wide environmental adaptability. SUMMARY

[0006] The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.

[0007] The present application aims to solve the above problems, and provides an environmental parameter compensation system for a non-contact tonometer blowing module, which solves the problem that the blowing air pressure is affected by environmental air pressure (such as altitude in different use places), temperature and humidity, and improves the measurement accuracy and environmental adaptability of the non-contact tonometer.

[0008] The technical scheme of the present application is as follows: the present application discloses an environmental parameter compensation system for a non-contact tonometer blowing module, which comprises an inflation module, a cylinder module, an in-cylinder air pressure sensor, a high-speed electromagnetic valve, an air outlet module, a dynamic air pressure sensor and an environmental parameter sensor.

[0009] The inflation module is connected to the input end of the cylinder module, and is used for inflating the cylinder and providing air source pressure.

[0010] The cylinder module is connected to the output end of the inflation module, receives the inflating gas, stores the compressed gas, and provides the air source for the blowing process.

[0011] The in-cylinder air pressure sensor is installed in the cylinder module, and is used for monitoring the air pressure in the cylinder in real time.

[0012] The high-speed electromagnetic valve is connected to the output end of the cylinder module, and is connected to the input end of the air outlet module.

[0013] The air outlet module is used as the outlet of the gas, and affects the speed and direction of the gas flow.

[0014] The dynamic air pressure sensor is installed near the air outlet module or the nozzle, and is used for monitoring the dynamic air pressure at the nozzle and feeding back the air pressure change in the blowing process in real time.

[0015] The environmental parameter sensor is used for detecting the environmental parameters.

[0016] According to an embodiment of the environmental parameter compensation system for the air blowing module of the non-contact tonometer of the application, the environmental parameter sensor is an environmental temperature and humidity sensor and / or an environmental air pressure sensor, the environmental temperature and humidity sensor is used to detect the temperature and humidity of the current environment to provide data for the temperature and humidity compensation, and the environmental air pressure sensor is used to detect the atmospheric pressure of the current environment to provide data for the air pressure compensation.

[0017] According to an embodiment of the environmental parameter compensation system for the air blowing module of the non-contact tonometer of the application, the system further comprises the following operation flow:

[0018] Step 1: receiving user input parameters;

[0019] Step 2: collecting data of the environmental parameter sensor and judging the validity of the data;

[0020] Step 3: calculating the saturated water vapor pressure;

[0021] Step 4: calculating the dry air partial pressure to exclude the humidity influence;

[0022] Step 5: calculating the air pressure value after the temperature and humidity compensation;

[0023] Step 6: calculating the valve opening time compensation;

[0024] Step 7: updating the user input parameters;

[0025] Step 8: executing air blowing by using the PID control algorithm of the air pump;

[0026] Step 8: calibrating, calculating and dynamically updating the application experience coefficient.

[0027] According to an embodiment of the environmental parameter compensation system for the air blowing module of the non-contact tonometer of the application, in step 1, the user input parameters include the air pressure target value in the air cylinder and the valve opening time.

[0028] According to an embodiment of the environmental parameter compensation system for the air blowing module of the non-contact tonometer of the application, in step 2, the environmental parameter sensor includes an environmental temperature and humidity sensor and an environmental air pressure sensor; the real-time data collected by the environmental parameter sensor includes: temperature , relative humidity , atmospheric pressure ; the data verification range of the environmental parameter sensor is: , ; the abnormal processing mechanism of the environmental parameter sensor is to trigger an error and terminate the system operation flow when the limit is exceeded.

[0029] According to an embodiment of the environmental parameter compensation system for the air blowing module of the non-contact tonometer of the present application, in step 3, the saturated water vapor pressure is calculated using the Antoine equation .

[0030] According to an embodiment of the environmental parameter compensation system for the air blowing module of the non-contact tonometer of the present application, in step 4, the water vapor partial pressure is calculated first :

[0031] ;

[0032] Then, the dry air pressure is obtained by excluding the humidity effect :

[0033] .

[0034] According to an embodiment of the environmental parameter compensation system for the air blowing module of the non-contact tonometer of the present application, in step 5, the target air pressure temperature compensation is calculated first: the air pressure value after temperature compensation is obtained by correcting the air pressure deviation in the cylinder caused by temperature change :

[0035] ,

[0036] wherein, is the target air pressure set by the user;

[0037] Then, the final value after temperature and humidity compensation is calculated :

[0038] ,

[0039] wherein, is the humidity air density correction factor.

[0040] According to an embodiment of the environmental parameter compensation system for the air blowing module of the non-contact tonometer of the present application, in step 6, the valve opening time is adjusted to :

[0041] .

[0042] According to an embodiment of the environmental parameter compensation system for the air blowing module of the non-contact tonometer of the present application, in step 9, further comprising:

[0043] First, the application experience coefficient is calibrated : the system is run and the dynamic air pressure sensor value is recorded ;

[0044] Then, the initial value of the application experience coefficient is calculated: ;

[0045] Finally, dynamically update the application experience coefficient : record after each run , and then update the previous coefficient value in a moving average manner :

[0046] , each time , The value will overwrite .

[0047] The present application has the following beneficial effects compared with the prior art: the system of the present application includes several sensors installed on the conventional blowing module and the corresponding algorithm system, which has the following advantages compared with the conventional technology:

[0048] 1) The accuracy of the blowing pressure of the blowing module each time is enhanced;

[0049] 2) The stability of the blowing pressure of the blowing module each time is enhanced;

[0050] 3) The adaptability of the working environment of the blowing module (different air pressure, altitude, temperature, humidity) is enhanced. BRIEF DESCRIPTION OF DRAWINGS

[0051] The above features and advantages of the present application can be better understood after reading the detailed description of embodiments of the present application in conjunction with the following drawings. In the drawings, components are not necessarily drawn to scale, and components having similar related properties or features can have the same or similar reference numerals.

[0052] Figure 1 A hardware structure diagram of an embodiment of the environmental parameter compensation system for the non-contact tonometer blowing module of the present application is shown.

[0053] Figure 2 A system workflow diagram of the environmental parameter compensation system embodiment for the non-contact tonometer blowing module shown in Figure 1 DETAILED DESCRIPTION

[0054] The present application is described in detail below in conjunction with the drawings and specific embodiments. Note that the aspects described below in conjunction with the drawings and specific embodiments are only exemplary and should not be understood as limiting the scope of protection of the present application in any way.

[0055] Figure 1 A hardware structure of an embodiment of the environmental parameter compensation system for the non-contact tonometer blowing module of the present application is shown. Please refer to Figure 1 ​​The system of the embodiment includes an inflation module, a cylinder module, an in-cylinder pressure sensor, a high-speed electromagnetic valve, an air outlet module, a dynamic pressure sensor, and an environmental parameter sensor, such as an environmental temperature and humidity sensor and an environmental pressure sensor. Figure 1 The environmental temperature and humidity sensor and the environmental pressure sensor can be one of the two or a combination of the two. The embodiment is described in combination with the two.

[0056] The inflation module and the cylinder module are located at the front end of the system. The inflation module is located upstream of the cylinder module and is used to provide a gas source for the cylinder. The in-cylinder pressure sensor is embedded in the cylinder module to monitor the gas pressure in the cylinder in real time. The high-speed electromagnetic valve is located between the cylinder module and the air outlet module and controls the on-off of the gas. The air outlet module and the dynamic pressure sensor are located at the end of the system. The air outlet module is responsible for spraying gas, and the dynamic pressure sensor is installed near the air outlet module or the nozzle to monitor the gas pressure at the nozzle. The environmental parameter sensor is installed at an appropriate position inside to detect environmental parameters. For example, in the embodiment, the environmental temperature and humidity sensor and the environmental pressure sensor are used to detect the temperature and humidity and the environmental pressure of the environment, respectively.

[0057] The output end of the inflation module is connected to the input end of the cylinder module to provide a gas source pressure for inflating the cylinder. The inflation module receives an inflation instruction and stops inflation according to the feedback of the in-cylinder pressure sensor.

[0058] The input end of the cylinder module is connected to the output end of the inflation module to receive the inflating gas and store the compressed gas to provide a gas source for the blowing process. The output end of the cylinder module is connected to the input end of the high-speed electromagnetic valve through a pipeline to release the gas during the blowing process.

[0059] The in-cylinder pressure sensor is installed inside the cylinder module to monitor the gas pressure in the cylinder in real time.

[0060] The input end of the high-speed electromagnetic valve is connected to the output end of the cylinder module, and the output end is connected to the input end of the air outlet module to receive the valve opening and closing instructions and control the on-off of the gas from the cylinder to the nozzle to start and end the blowing process.

[0061] The air outlet module serves as the outlet for gas spraying and affects the speed and direction of the gas flow. The input end of the air outlet module is connected to the output end of the high-speed electromagnetic valve to receive the gas released from the cylinder. The output end of the air outlet module is connected to the nozzle to spray the gas towards the cornea.

[0062] The dynamic pressure sensor is installed near the air outlet module or the nozzle to monitor the dynamic pressure at the nozzle and provide real-time feedback on the gas pressure changes during the blowing process.

[0063] The environmental temperature and humidity sensor is used to detect the temperature and humidity of the current environment to provide data for temperature and humidity compensation.

[0064] The ambient pressure sensor is used to detect the atmospheric pressure of the current environment to provide data for pressure compensation.

[0065] The operation flow of the system is as follows:

[0066] 1. Write parameters: the user manually inputs the target value of the cylinder inflation pressure and the valve opening time.

[0067] 2. Inflation stage: the inflation module is started to inflate the cylinder, and the cylinder pressure sensor detects the pressure, which stops when the set value is reached.

[0068] 3. Blow stage: the high-speed electromagnetic valve is opened, and the gas in the cylinder is sprayed out through the outlet module. At this time, the following modules work simultaneously: the cylinder pressure sensor reads the pressure in the cylinder; the dynamic pressure sensor reads the real-time injection pressure at the nozzle.

[0069] 4. Closing stage: the high-speed electromagnetic valve is closed, and the blow is stopped. The inflation module can be re-inflated to the set pressure as needed.

[0070] The operation flow is specifically shown in Figure 2 The following is a detailed description of the system operation flow.

[0071] Step 1: User input parameters.

[0072] In this step, the user manually writes the target value of the cylinder inflation pressure and the valve opening time.

[0073] Step 2: Collect data from environmental parameter sensors and judge the validity of the data.

[0074] In this step, the real-time environmental temperature and humidity and environmental pressure are collected by the environmental temperature and humidity sensor and the environmental pressure sensor in the system as the input basis for compensation calculation.

[0075] Among them, the real-time data of the environmental parameter sensor includes: temperature T env (℃), relative humidity RH (%), atmospheric pressure P atm (mmHg). The data verification range of the environmental parameter sensor is: , The abnormal processing mechanism of the environmental parameter sensor is: when the limit is exceeded, an error is triggered and the system operation flow is terminated.

[0076] Step 3: Calculate the saturated water vapor pressure (Psat).

[0077] In this step, the Antoine equation is used to calculate the saturated water vapor pressure. The saturated water vapor pressure is the core parameter of humidity compensation, which reflects the maximum possible pressure of water vapor in the air at the current temperature Psat (unit: mmHg):

[0078] The formula is the Magnus formula, an empirical formula used to calculate saturated vapor pressure. The 0.75006 at the end is to convert hPa to mmHg.

[0079] Step 4: Calculate the partial pressure of dry air (Pdry) to eliminate the influence of humidity.

[0080] In this step, the partial pressure of water vapor (P) is first calculated. vapor ):

[0081] ;

[0082] Then, to eliminate the influence of humidity, the dry air pressure is obtained ( ):

[0083] .

[0084] This step also includes an exception handling mechanism: if the final result is... If the value is less than 0, an error message "Humidity data abnormal" will be displayed and the process will be terminated.

[0085] Step 5: Calculate the air pressure value after temperature and humidity compensation.

[0086] In this step, the target air pressure temperature compensation is first calculated: the cylinder gas pressure deviation caused by temperature changes is corrected (ideal gas law) to obtain the temperature-compensated air pressure value. :

[0087]

[0088] in, This is the user-defined target air pressure (mmHg), i.e., the air pressure used for cylinder inflation, such as 200 mmHg. The 273.15 in the formula is the offset for converting Celsius (°C) to Kelvin (K), where 0°C = 273.15K; the 298 below is the Kelvin temperature (298K) corresponding to the standard temperature of 25°C. The unit is Celsius.

[0089] Next, calculate the target air pressure and humidity compensation: the density of dry air decreases in humid air, so the target air pressure is further corrected based on the previous step to obtain the final value after temperature and humidity compensation. :

[0090]

[0091] in, It is the moist air density correction factor.

[0092] Step 6: Calculate the valve opening time ( )compensate.

[0093] In this step, the ambient air pressure (altitude) affects the gas flow rate, and the valve opening time needs to be adjusted to , to maintain a consistent amount of air injection:

[0094]

[0095] Where the standard atmospheric pressure is 101.325 kPa, converted to mmHg is 760 mmHg.

[0096] Step 7: Update user input parameters.

[0097] Through the temperature and humidity compensation and valve opening time compensation in the above steps, the user input air pressure parameter is updated to , and the valve opening time is updated to .

[0098] Step 8: Execute the air injection using the air pump PID control algorithm.

[0099] The air pump PID control algorithm adjusts the air pump PWM duty cycle through proportional and integral adjustment to stabilize the target air pressure.

[0100] First, set the initial parameters in the algorithm: proportional parameter , integral parameter , derivative parameter , and control period . The proportional parameter adjusts the air pump power quickly according to the difference between the current air pressure and the target; the integral parameter accumulates historical errors to compensate for long-term deviations such as air pump leakage; the derivative parameter predicts the trend of air pressure changes to slow down in advance to prevent overshooting the target value; the control period , i.e. the sampling interval, determines the frequency of PID calculation and affects the calculation granularity of integral and derivative.

[0101] The initial parameters are determined as follows:

[0102] : Set and to 0, and adjust to the extent that the system responds quickly without excessive overshoot or oscillation;

[0103] : After adjusting the proportional coefficient, gradually increase the integral coefficient so that the system can eliminate long-term errors;

[0104] : Adjust the derivative coefficient so that it adjusts the output according to the error change rate to reduce system oscillation.

[0105] If the pressure curve is jagged, it means that the system load is too large or the system load is too small.

[0106] After adjustment according to the above method, the values of , , and are determined as follows: =0.5、 =0.1、 =0.05、 =30ms.

[0107] Then, the pressure sampling is performed: for example, the in-cylinder pressure sensor pressure value is read every 30ms .

[0108] The error is calculated again:

[0109] ;

[0110] The proportional term parameter , the integral term parameter and the differential term parameter for the comprehensive PID output are calculated.

[0111] The proportional term parameter : ;

[0112] The integral term parameter : the cumulative error , the integral output ;

[0113] The differential term parameter : the error change rate , the differential output .

[0114] The final comprehensive PID output is obtained, and the PWM duty cycle is: .The output of the PID control determines the PWM duty cycle of the air pump and is a dimensionless pure number, but corresponds to the percentage of the PWM duty cycle. For example, =50 means that the PWM duty cycle is 50%.

[0115] Step 9: Calibration, calculation, and dynamic updating of the experience coefficient .

[0116] The experience coefficient is the parameter to calibrate the actual physical deviation in the system, its core role is to bridge the gap between the ideal model and the actual system, to ensure that the blowing system remains consistent. The application of empirical coefficient is to correct the valve opening time calculated by the theory, to compensate for some actual factors not covered by the theoretical model. The object of the aforementioned PID control is the air pump (inflation stage), the goal is to accurately control the air pressure stored in the cylinder, and its update method is as described in the previous step, which is to make real-time adjustments during the air pump inflation stage, and to adapt through real-time adjustment of PWM; while the empirical coefficient of this step is the object of the electromagnetic valve opening time (jet stage), and the goal is to accurately control the jet output flow, and its update method is to adjust the valve opening time (the value is updated every time the system works completely ) when the next jet is not consistent with the ideal value after the sensor reads the blowing pressure value after the system works completely , and the value is updated by rolling to adapt.

[0117] Due to the response delay of different electromagnetic valves, the inconsistency of nozzle inner diameter, and some errors in the actual system, such as the system error of the sensor, the actual value obtained during testing will deviate from the theoretical value, and the introduction of empirical coefficient can reduce the deviation caused by these steady-state errors. For example: suppose the calculated valve opening time is 3000us, but the nozzle inner diameter has a slight error (for example, the diameter is 90% of the normal value), if not compensated by , the jet pressure will not meet the requirements. During system operation, it is found that the actual air output value is 90% of the normal value (at this time the system does not know that it is caused by the inner diameter error, only that the actual value has a 10% deviation), after correction by , =1 / 0.9≈1.11, then according to the result, compensation is made again: 3000×1.11=3330us. Next time 3000us will be corrected to 3330us.

[0118] In this step, by applying empirical coefficient each time, the actual factors not covered by the theoretical model (such as timer delay, pipe material friction, etc.) are compensated.

[0119] First, calibrate the application of empirical coefficient : run the system, record the dynamic air pressure sensor value (i.e. the actual measured blowing pressure value) .

[0120] Then calculate the initial value of the empirical coefficient : .

[0121] Finally, dynamically update the application experience coefficient : record after each run Then, update the previous coefficient value in a moving average manner For :

[0122] ,

[0123] In the above formula, 0.9 and 0.1 are the weight distribution of the weighted average, which is equivalent to a first-order low-pass filter. The commonly used weight ratio in the industry is 0.85-0.95 / 0.15-0.05, and 0.9 / 0.1 is a parameter that takes into account reliability and sensitivity. 0.9 is the historical full, and 0.1 is the weight of new data. The reason why the weight of new data is 0.1 is that if a non-steady-state external disturbance occurs and noise is generated, the influence of the noise on the system can be reduced to 1 / 10.

[0124] Each time After, The value will overwrite .

[0125] Although the above methods are illustrated and described as a series of acts, it will be appreciated that the methods are not limited by the order of acts as some acts can, in accordance with one or more embodiments, occur simultaneously or in different orders than shown and described herein. In addition, not all illustrated acts can be required to implement the methods in accordance with one or more embodiments.

[0126] One skilled in the art will further appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the embodiments disclosed herein can be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality, without reference to a specific

[0127] The various illustrative logical blocks, modules, and circuits described in connection with the embodiments disclosed herein can be implemented or performed with a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor can be a microprocessor, but in the alternative, the processor can be any conventional processor, controller, microcontroller, or state machine. A processor can also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0128] The steps of a method or algorithm described in connection with the embodiments disclosed herein can be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module can reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium can be integral to the processor. The processor and the storage medium can reside in an ASIC. The ASIC can reside in a user terminal. In the alternative, the processor and the storage medium can reside as discrete components in a user terminal.

[0129] In one or more exemplary embodiments, the functions described can be implemented in hardware, software, firmware, or any combination thereof. If implemented in software as a computer program product, the functions can be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media can be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.

[0130] The previous description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other variations without departing from the spirit or scope of the disclosure. Thus, the disclosure is not intended to be limited to the examples described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An environmental parameter compensation system for a non-contact tonometer air puff module, characterized by, The system comprises an inflation module, a cylinder module, an in-cylinder gas pressure sensor, a high-speed electromagnetic valve, an air outlet module, a dynamic air pressure sensor, and an environmental parameter sensor, wherein: The inflation module is connected to the input end of the cylinder module for inflating the cylinder, providing a gas source pressure, and receiving inflation instructions and stopping inflation according to the feedback of the in-cylinder gas pressure sensor; The cylinder module receives the inflating gas, stores compressed gas, and provides a gas source for the blowing process, and the output end of the cylinder module is connected to the input end of the high-speed electromagnetic valve through a pipeline for releasing gas during the blowing stage; The in-cylinder gas pressure sensor is installed inside the cylinder module for real-time monitoring of the gas pressure in the cylinder; The high-speed electromagnetic valve is connected to the output end of the cylinder module, and its output end is connected to the input end of the air outlet module to receive valve opening and closing instructions, control the on-off of gas from the cylinder to the nozzle, and realize the start and end of blowing; The air outlet module is the outlet for gas ejection, affecting the speed and direction of the gas flow, and its input end is connected to the output end of the high-speed electromagnetic valve to receive the gas released from the cylinder, and its output end is connected to the nozzle to spray gas to the external object; The dynamic air pressure sensor is installed near the air outlet module or the nozzle to monitor the dynamic air pressure at the nozzle for real-time feedback of the air pressure change during the blowing process; The environmental parameter sensor is used to detect environmental parameters; The system further comprises the following operation process: Step 1: Receive user input parameters; Step 2: Collect data from the environmental parameter sensor and determine data validity; Step 3: Calculate the saturated water vapor pressure; Step 4: Calculate the dry air partial pressure to exclude the influence of humidity; Step 5: Calculate the air pressure value after temperature and humidity compensation; Step 6: Calculate the valve opening time compensation; Step 7: Update user input parameters; Step 8: Perform blowing using a gas pump PID control algorithm; Step 9: Calibrate, calculate, and dynamically update application experience coefficients; wherein in step 3, the saturated water vapor pressure is calculated using the Antoine equation The saturated water vapor pressure is the core parameter for humidity compensation: wherein is the temperature in the environmental parameter sensor real-time data; wherein in step 6, the opening valve time adjusted to : , Pd is the dry air pressure; In step 8, further comprising: First, set the initial parameters in the PID control algorithm of the air pump: the proportional parameter , the integral parameter , the derivative parameter , and the control period . The proportional parameter quickly adjusts the air pump power according to the difference between the current air pressure and the target; the integral parameter accumulates historical errors to compensate for the long-term deviation of the air pump leakage; the derivative parameter predicts the trend of air pressure changes to slow down in advance to prevent overshooting the target value; and the control period , i.e., the sampling interval, determines the frequency of PID calculation and affects the calculation granularity of integration and differentiation. Then, the air pressure sampling is performed, and the in-cylinder air pressure sensor air pressure value is read every set time length ; Recalculate error : wherein is a target air pressure set by the user; After calculating the proportional term parameter for the integrated PID output , the integral term parameter and the differential term parameter : proportionality term parameter : ; integral term parameter : accumulated error , integral output ; Differential term parameter : ; Finally, the PID outputs are integrated to obtain the PWM duty cycle: .

2. The environmental parameter compensation system for a non-contact tonometer air puff module of claim 1, wherein, The environmental parameter sensor is an environmental temperature and humidity sensor and / or an environmental air pressure sensor, the environmental temperature and humidity sensor is used to detect the temperature and humidity of the current environment to provide data for temperature and humidity compensation, and the environmental air pressure sensor is used to detect the atmospheric pressure of the current environment to provide data for air pressure compensation.

3. The environmental parameter compensation system for a non-contact tonometer air puff module of claim 2, wherein, In step 1, the user input parameters include the target value of the gas pressure in the cylinder and the valve opening time.

4. The environmental parameter compensation system for a non-contact tonometer air puff module of claim 3, wherein, In step 2, the environmental parameter sensor includes an environmental temperature and humidity sensor and an environmental air pressure sensor; The real-time data collected by the environmental parameter sensor includes temperature , relative humidity , and atmospheric pressure . The data verification range of the environmental parameter sensor is , . The abnormal processing mechanism of the environmental parameter sensor is to trigger an error and terminate the system running process when the limit is exceeded.

5. The environmental parameter compensation system for a non-contact tonometer air puff module of claim 4, wherein, In step 4, the water vapor partial pressure is first calculated : ； Then, to exclude the effect of humidity, the dry air pressure : 。 6. The environmental parameter compensation system for a non-contact tonometer air puff module of claim 5, wherein, In step 5, the target air pressure temperature compensation is calculated first: the air pressure value after temperature compensation is obtained by correcting the air pressure deviation in the cylinder due to temperature change : wherein, is a target air pressure set by the user; Recalculating the final value after temperature and humidity compensation : ， wherein is the wet air density correction factor.

7. The environmental parameter compensation system for a non-contact tonometer air puff module of claim 6, wherein, In step 9, further comprising: First calibrate the application experience coefficient : Run the system, record the dynamic air pressure sensor values ; Then the initial value of the experience coefficient is calculated ;​ Finally, dynamically update the application experience coefficient : record after each run , and update the previous coefficient value using the moving average method for : each time a value is derived after, the value will override .

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