Non-contact tonometric visual calibration method

Abstract

The application belongs to the technical field of micro electro mechanical system, and particularly relates to a non-contact intraocular pressure visual calibration method, which is simplified by means of an AI model of human eyes and an intraocular pressure deformation variable detection device, combined with MEMS technology and visual analysis theory, and realizes accurate monitoring of corneal deformation by real-time and dynamic simulation of human eye pressure, data collection by optical or image sensors, provides a more accurate intraocular pressure evaluation method, and realizes effective verification of a non-contact tonometer. Compared with the prior art, the application has the beneficial effects that: the application can realize accurate monitoring of corneal deformation by means of optical or image sensors for data collection, can realize accurate monitoring of human corneal pressure by integrating corneal deformation variable calculation and analysis algorithms in MEMS sensors through integrated technology, and can realize dynamic monitoring.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of Micro-electro Mechanical Systems (MEMS), and particularly relates to a non-contact visual calibration method for intraocular pressure. BACKGROUND

[0002] Intraocular pressure (IOP) is the pressure exerted by the contents of the eye on the wall of the eye, and is an important physiological indicator of eye health. Normal range of intraocular pressure is usually between 10-21 mmHg. Fluctuations in intraocular pressure can reflect the occurrence of eye diseases, such as glaucoma, retinal disease, etc. Abnormal intraocular pressure levels, especially persistently elevated intraocular pressure, are one of the main pathological features of glaucoma, which can cause damage to the optic nerve and eventually lead to irreversible loss of vision. Therefore, accurate monitoring of intraocular pressure is of great significance for early detection and treatment of glaucoma.

[0003] Micro-Electro-Mechanical Systems (MEMS) technology is a microsystem technology that integrates microelectronics technology, mechanical engineering, materials science and other multidisciplinary technologies. The advantages of MEMS technology include small size, light weight, low power consumption, low cost and high precision, making it widely used in sensor and actuator design. In recent years, MEMS technology has developed rapidly in the medical field, especially in the application of physiological monitoring devices such as pressure sensors, acceleration sensors, etc. The intraocular pressure sensor designed using MEMS technology can realize a miniaturized, low-power non-contact monitoring system, enhancing patient comfort and compliance.

[0004] Currently, intraocular pressure monitoring technology can be roughly divided into two categories: contact and non-contact. Contact tonometers, such as Goldmann applanation tonometers, are devices that measure intraocular pressure by directly contacting the cornea of the eye. This device calculates the intraocular pressure value by measuring the degree of deformation of the cornea. Although it has high precision, contact tonometers usually require anesthesia of the eye to reduce discomfort and can cause corneal abrasion, infection, etc.

[0005] Non-contact tonometers (such as pneumatic tonometers) measure intraocular pressure by flattening the cornea with a gentle jet of air. This method avoids direct contact with the cornea, reducing the risk of infection and eliminating the need for anesthetic. Non-contact tonometers are generally high-value, expensive equipment in medical institutions that require regular calibration. Existing calibration techniques mainly use iris images (a method for testing intraocular pressure, application number 202310832210.6) or liquid pressure detection (a non-contact tonometer precision calibration device and calibration method, application number 201610118850.0). Factors such as corneal thickness, curvature, and environmental light affect the stability and accuracy of the measurement data. SUMMARY

[0006] The purpose of the present application is to provide a non-contact intraocular pressure visual calibration method that overcomes the shortcomings of the prior art. By combining MEMS technology and visual analysis theory, the present application can accurately monitor the deformation of the cornea by real-time and dynamic simulation of the pressure on the human eye, provide a more accurate intraocular pressure evaluation method, and effectively calibrate non-contact tonometers to improve the reference value of non-contact tonometers in clinical applications.

[0007] To achieve the above-mentioned purpose, the present application realizes the following technical solutions:

[0008] A non-contact intraocular pressure visual calibration method, characterized by using a simplified AI model of the human eye and an intraocular pressure deformation detection device, combining MEMS technology and visual analysis theory, and collecting data from optical or image sensors through real-time and dynamic simulation of the pressure on the human eye. The present application can accurately monitor the deformation of the cornea, provide a more accurate intraocular pressure evaluation method, and effectively calibrate non-contact tonometers. The specific process is as follows:

[0009] Step 1: Place the bionic eye in the intraocular pressure deformation detection device and embed it in the fixed base. Seal the periphery with glue. Take the center of the cornea of the bionic eye as the origin O, add multiple observation points on the cornea, and record them.

[0010] Step 2: Place the intraocular pressure deformation detection device under the objective lens of the electron microscope.

[0011] Step 3: Start the liquid injection metering pump and inject artificial aqueous humor into the bionic eye. Monitor the left and right deviation angles and the up and down deviation angles of each observation point, and obtain the central corneal thickness deformation of the bionic eye.

[0012] Step 4: Send the central corneal thickness deformation information to the data analysis terminal to obtain the intraocular pressure data of the bionic eye and correct the reading of the non-contact tonometer.

[0013] The human eye simplified AI model is obtained based on an image recognition neural network deep learning method, observation points are set on the cornea, the cornea is photographed under normal intraocular pressure, and the cornea is photographed again when the intraocular pressure rises, the observation points in the photographed photos are offset, and the offsets are used as the basis for neural network learning and judgment, so that the intraocular pressure condition is accurately fed back by analyzing the cornea images before and after the intraocular pressure changes.

[0014] The intraocular pressure deformation variable detection device comprises a fixed base, a liquid injection metering pump and a data analysis terminal, the fixed base is provided with a bionic eye positioning groove, the bottom of the groove is provided with a heater and water supply channels and a drainage channel, the water supply channel is connected with the liquid injection metering pump through a pipeline, the drainage channel is connected with a pressure test cavity, the pressure test cavity is provided with a pressure sensor, and the fixed base is provided with a temperature sensor.

[0015] Further, the top of the water supply channel is connected with the bottom center of the bionic eye through a liquid distribution sheet, the upper surface of the liquid distribution sheet is provided with a micropore array, the micropore size is 0.1-0.3mm, the adjacent hole spacing is 10-18 degrees, and there are 20-36 holes in total.

[0016] Further, the top end of the drainage channel is connected with the bottom periphery of the bionic eye, the bottom end of the drainage channel is connected with the pressure test cavity in communication through a collecting pipe, and the bottom of the pressure test cavity is provided with an emptying valve.

[0017] Further, the distribution of the observation point position adopts a geographic coordinate system, the latitude and longitude graduation accuracy is 0.1-0.5mm, and the graduation line is ablated on the cornea surface of the bionic eye by a laser marking machine.

[0018] Further, the electron microscope is a scanning electron microscope or a confocal microscope.

[0019] Further, the bionic eye is a hydrogel artificial eye or a "bionic eye" of the German company Retina Implant AG; the pressure sensor is a MEMS pressure sensor; the intraocular pressure deformation variable detection device is 3D printed, the heater is a hollow structure, and heating electric oil is injected into the hollow structure; after the heating electric oil is baked, dried and solidified, the two wires are connected with the power supply, and the power is 4-10W.

[0020] Further, the artificial aqueous humor is a mixed solution of physiological saline and sodium bicarbonate, wherein the concentration of the physiological saline is 125mmol / L, and the concentration of the sodium bicarbonate is 24mmol / L.

[0021] Further, the operation process of the liquid injection metering pump in step 3 is as follows: 1) the artificial aqueous humor is injected into the bionic eye through the liquid injection metering pump, and the injection amount is 0.1-0.3ml; Inject the artificial aqueous humor into the fixed base at a speed of cm / s. Once the fixed base is filled with artificial aqueous humor, record the injection time, corneal deformation information, and pressure value. 2) While ensuring that the overall injection time remains unchanged, increase the injection speed by 1% and record the corneal central thickness deformation information and pressure value. 3) Stop the injection when the pressure reaches the upper limit of high intraocular pressure, 30 mmHg.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] 1) This invention is based on the image recognition neural network deep learning method, and uses optical or image sensors to collect data. It uses corneal deformation as an indicator for monitoring intraocular pressure changes. Through accurate monitoring of corneal deformation, it can achieve accurate monitoring of human corneal pressure and realize dynamic monitoring.

[0024] 2) This invention, taking into full account the structure of the eyeball and the biomechanics of human tissues, uses a combination of numerical simulation and experimental verification with COMSOL software to determine the region of maximum corneal deformation under pressure changes. Based on this, a corneal deformation calculation and analysis software algorithm is designed. Subsequently, this algorithm is used to analyze the central corneal thickness of the patient (when the intraocular pressure is within the normal range, that is, less than 21 mmHg, the central corneal thickness is mean ± standard deviation: 0.545 ± 0.033 mm, while when the patient has high intraocular pressure, the central corneal thickness is approximately 0.592 ± 0.039 mm, that is, the relationship between intraocular pressure and central corneal thickness is non-linear), thereby obtaining the precise changes in the patient's intraocular pressure and providing a more reliable and accurate dynamic assessment of intraocular pressure.

[0025] 3) The complex intraocular structure is simplified into a simplified model consisting of only three parts: a bionic artificial cornea, a liquid injection structure, and a liquid discharge structure. This reduces the difficulty of fabricating the detection device. Based on this, a flow resistance model for the liquid discharge outlet is established by combining mathematical equations from microfluidics and solid mechanics. COMSOL simulation software is used to analyze the influence of internal factors such as differences in patient eye structure, corneal thickness, and elasticity of the liquid discharge outlet tissue, as well as external factors such as ambient temperature and human posture, on the relationship between intraocular pressure and corneal deformation. The quantitative relationship and variation law between intraocular pressure and corneal deformation are obtained. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of an embodiment of the present invention;

[0027] Figure 2 This is a schematic diagram of the intraocular pressure deformation detection device in an embodiment of the present invention;

[0028] Figure 3 for Figure 2 Top view;

[0029] Figure 4 is Figure 2 the structural explosion diagram of the application;

[0030] Figure 5 is the schematic diagram of the water supply channel structure in the embodiment of the application;

[0031] Figure 6 is the schematic diagram of the water drainage channel distribution in the embodiment of the application;

[0032] Figure 7 is the schematic diagram of the heater structure in the embodiment of the application;

[0033] Figure 8 is the schematic diagram of the pressure test cavity structure in the embodiment of the application;

[0034] Figure 9 is the schematic diagram of the corneal topographic coordinate system reference line in the embodiment of the application;

[0035] Figure 10 is the deviation curve of the measured value and the standard pressure in the embodiment of the application.

[0036] In the figure: 1-bionic eye; 2-fixed base; 3-data analysis terminal; 4-liquid injection metering pump; 5-power supply; 6-electron microscope; 7-bionic eye positioning groove; 8-heater; 9-water supply channel; 10-drainage channel; 11-electrode; 12-collector pipe; 13-pressure test cavity; 14-pressure sensor; 15-temperature sensor; 16-liquid dispersion sheet. DETAILED DESCRIPTION

[0037] The technical solutions of the application will be described clearly and completely in the specific embodiments below. Obviously, the described embodiments are some of the embodiments of the application, not all of the embodiments.

[0038] In order to more clearly illustrate the specific embodiments of the application or the technical solutions in the prior art, the specific embodiments needed in the description of the specific embodiments or the prior art will be briefly introduced. Obviously, the specific embodiments described below are some embodiments of the application, and those skilled in the art can obtain other specific embodiments without creative labor on the basis of these specific embodiments.

[0039] The components of the embodiments of the application described and shown in the specific embodiments herein can be arranged and designed in countless different configurations. Therefore, the following detailed description of the embodiments of the application provided in the specific embodiments is not intended to limit the scope of the claimed application, but only represents selected embodiments of the application.

[0040] See Figures 1-8It is a non-contact intraocular pressure visual calibration method embodiment structure schematic view of the application, with the help of a human eye simplified AI model and an intraocular pressure deformation variable detection device, combining MEMS technology and visual analysis theory, through real-time and dynamic simulation of human eye pressure, data acquisition by an optical or image sensor, accurate monitoring of corneal deformation is realized, a more accurate intraocular pressure evaluation method is provided, effective verification of the non-contact tonometer is realized, and the specific process is as follows:

[0041] Step 1: Put the bionic eye 1 into the intraocular pressure deformation variable detection device, and embed it into the fixed base 2, seal the periphery with glue, take the corneal center of the bionic eye 1 as the origin O, add multiple observation points on the cornea, and record them;

[0042] Step 2: Place the intraocular pressure deformation variable detection device under the objective lens of the electron microscope 6;

[0043] Step 3: Start the liquid injection metering pump 4, inject artificial aqueous humor into the bionic eye 1, monitor the left and right deviation angles and the up and down deviation angles of each observation point in the corneal center, and obtain the deformation variable of the corneal central thickness of the bionic eye 1; the operation process of the liquid injection metering pump 4 is as follows: 1) inject the artificial aqueous humor into the fixed base 2 at a speed of cm / s, and when the artificial aqueous humor fills the fixed base 2, record the injection time, corneal deformation variable information and pressure value; 2) under the condition that the total injection time is unchanged, increase the injection speed by 1%, record the corneal deformation variable information and pressure value; 3) when the pressure reaches the high intraocular pressure upper limit value 30mmHg, stop injection;

[0044] Step 4: Send the corneal deformation variable information to the data analysis terminal 3, obtain the intraocular pressure data of the bionic eye, and correct the reading of the non-contact tonometer. The whole system is powered by the power supply 5.

[0045] In the embodiment of the application, the human eye simplified AI model is obtained based on an image recognition neural network deep learning method, the observation points are set on the cornea, the cornea is photographed under normal intraocular pressure, and the cornea is photographed again when the intraocular pressure rises. The observation points in the photographed photos are offset, and these offset amounts are used as the basis for neural network learning and discrimination, so that the intraocular pressure situation is accurately fed back by analyzing the corneal images before and after the intraocular pressure changes.

[0046] The intraocular pressure deformation variable detection device comprises a fixed base 2, a liquid injection metering pump 4 and a data analysis terminal 3, the fixed base 2 is provided with a bionic eye positioning groove 7, the bottom of the groove is provided with a heater 8, a water supply channel 9 and a drainage channel 10, the water supply channel 9 is connected with the liquid injection metering pump 4 through a pipeline, the drainage channel 10 is connected with a pressure test cavity 13, the pressure test cavity 13 is provided with a pressure sensor 14, the fixed base 2 is provided with a temperature sensor 15, and the pressure sensor 14 and the temperature sensor 15 are connected with the data analysis terminal 3 through data cables respectively.

[0047] All components of the intraocular pressure deformation variable detection device in the embodiment of the application are made of QbeamLab type commercialized open source electron beam metal 3D printing equipment. According to the application environment of the device and considering the cost factor, a copper alloy with good corrosion resistance and low price is selected as the main material of the device. First, COMSOL software is used for modeling, then the three-dimensional model of the device is cut into a series of cross-section slices along the selected forming direction by using the GMslicer slicing software matched with the 3D printer, and the sliced device is imported into the memory of the printer. (The GMslicer software has an automatic layout function, uses a high-efficiency parallel algorithm for slicing, and can output multiple layer formats including CLI and STL. ) The CLI layer file or STL three-dimensional model file output by the GMslicer slicing software is processed by using the process control software metaBuild. (The metaBuild software opens source of 7 groups of more than 100 process parameters, allows user programming, and can specify process parameters of all models, thereby improving process optimization efficiency.)

[0048] The water supply channel 9 is directly opened to the bionic eye positioning groove 7, the bionic eye 1 is placed in the bionic eye positioning groove 7, and the periphery thereof is in a sealed state, and the gap between the bionic eye positioning groove 7 and the bionic eye 1 is filled with the simulated aqueous humor.

[0049] The top of the water supply channel 9 is connected with the bottom center of the bionic eye through a liquid distribution sheet 16, the upper surface of the liquid distribution sheet 16 is provided with a micro-hole array, the size of the micro-hole is 0.1-0.3mm, the distance between adjacent holes is 10 degrees, and there are 36 holes in total. The water supply channel 9 and the liquid distribution sheet 16 can make the simulated aqueous humor uniformly distributed in the bionic eye positioning groove 7.

[0050] The top end of the drainage channel 10 is connected with the bottom periphery of the bionic eye 1, the bottom end of the drainage channel 10 is connected with the pressure test cavity 13 through the collecting pipe 12, and the bottom of the pressure test cavity 13 is provided with an emptying valve. The drainage channel 10 is an internal liquid discharge channel of the bionic eye 1, and the drainage channel 10 simulates the structure of a liquid discharge port in a real human eye; the drainage channel 10 is a 1mm-diameter hollow pipe, the drainage channels 10 are uniformly distributed above the collecting pipe 12, the collecting pipe 12 has a ring structure, and there is a gap between the bionic eye positioning groove 7 and the bionic eye 1; when the bionic eye positioning groove 7 is filled with the simulated aqueous humor, the pressure will force the simulated aqueous humor to flow out from the drainage channel 10 and into the collecting pipe 12; when the gap is filled, the simulated aqueous humor will flow into the pressure test cavity 13 and exert pressure on the pressure sensor 14.

[0051] The pressure sensor 14 can be a differential pressure sensor, a vector pressure sensor or a capacitive pressure sensor, wherein: the differential pressure sensor is suitable for measuring a small range of pressure of 5-60mmHg, and the measurement accuracy can reach 0.1%; the vector pressure sensor is also suitable for pressure measurement of 5-60mmHg, can measure multiple pressure values at the same time, and the accuracy is about 0.5%; and the capacitive pressure sensor has a measurement range of 0-100mmHg, and the accuracy can reach 0.2%.

[0052] See Figure 9 The corneal surface adopts a geodetic coordinate system graduation line, and the latitude and longitude graduation accuracy is 0.1-0.5mm, preferably 0.2mm. The graduation line is ablated on the corneal surface of the bionic eye by a laser marking machine. The observation point is used to simulate the specific distribution of cell positions in the corneal endothelium or epithelial microscopic image.

[0053] In the embodiment, the electron microscope is a scanning electron microscope or a confocal microscope. The bionic eye is a “bionic eye” of Retina Implant AG in Germany. The pressure sensor is a MEMS pressure sensor; and the artificial aqueous humor is a mixed solution of physiological saline and sodium bicarbonate, wherein the concentration of the physiological saline is 125mmol / L, and the concentration of the sodium bicarbonate is 24mmol / L.

[0054] The intraocular pressure deformation variable detection device is 3D printed, the heater 8 has a hollow structure and is prepared by using a MEMS process and conductive paste, and heating electric oil (CN5001 heating electric oil of Xinghongyang Technology Co., Ltd.) is injected into the heater 8. After the heating electric oil is baked, dried and cured, the two electrodes 11 are connected with a power supply, the heating power is 8W, and after the power supply is turned on, the voltage is adjusted to be between 5V and 6V, so that the bionic eye 1 can be heated to 37° to simulate the change of the body temperature of a patient.

[0055] See Figure 10The deviation curve of the measured value of the embodiment of the present application from the standard pressure can be seen, the error of the present application and the central corneal thickness present a linear relationship, when the central corneal thickness is in a reasonable range, the present application can well infer the intraocular pressure of the patient according to the central corneal thickness, and realizes the non-contact intraocular pressure calibration.

[0056] The present application can fully consider the patient individual differences such as eyeball structure and human tissue biomechanics, and external factors such as environmental temperature and human posture on the corresponding relationship between the intraocular pressure and the central corneal thickness deformation, determine the maximum deformation region of the patient's cornea under pressure change through the COMSOL simulation software and experimental verification, and design the corneal deformation calculation and analysis software algorithm based on this, then analyze the relative position change of the cells distributed in the patient's corneal epithelium or endothelium micrograph to calculate the patient's corneal deformation, and then get the accurate change of the patient's intraocular pressure.

[0057] The 3D printing equipment used in the embodiment selects a QbeamLab type commercial open source electron beam metal 3D printing equipment. The QbeamLab type commercial open source electron beam metal 3D printing equipment is an open source electron beam metal 3D printer, which has multiple advantages such as open source process parameters, modularization customization, active powder supply, grid scanning heating, electron beam automatic calibration, process online monitoring, and supports multiple metal materials such as titanium alloy, high-temperature alloy, high-melting-point alloy and copper alloy. The main technical parameters of the QbeamLab type commercial open source electron beam metal 3D printing equipment are as follows: the maximum forming size is 200*200*240mm3, the precision is ±0.2mm, the electron beam maximum power is 3kW, the electron beam accelerating voltage is 60kV, the electron beam current is 0-50mA, the cathode type is tungsten filament direct heating type, the minimum beam spot diameter is 200um, the electron beam maximum jump speed is 10,000m / s, the limit vacuum is 10-2Pa, the helium gas partial pressure is adjustable between 0.05-1.0Pa, the grid scanning method is used to heat the powder bed, the powder bed surface temperature can reach 1100℃, the active cooling block is used for part cooling, and the optical camera is used for process monitoring.

[0058] Although the embodiments of the present application have been shown and described, it can be understood by those of ordinary skill in the art that various changes, modifications, replacements and variations can be made to these embodiments without departing from the principles and spirits of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A non-contact intraocular pressure visual calibration method, characterized by, With the help of the human eye simplified AI model and the intraocular pressure deformation variable detection device, combined with MEMS technology and visual analysis theory, through real-time and dynamic simulation of human eye pressure, data collection by optical or image sensor, accurate monitoring of corneal deformation is realized, more accurate intraocular pressure evaluation means is provided, and effective verification of non-contact tonometer is realized, the specific process is as follows: Step 1: put the bionic eye into the intraocular pressure deformation variable detection device, and embed it into the fixed base, seal the periphery with glue, take the center of the cornea of the bionic eye as the origin O, add multiple observation points on the cornea, and record them; Step 2: place the intraocular pressure deformation variable detection device under the objective lens of the electron microscope; Step 3: start the liquid injection metering pump, inject artificial aqueous humor into the bionic eye, monitor the left and right deviation angles and the up and down deviation angles of each observation point, and obtain the central corneal thickness deformation variable of the bionic eye; Step 4: send the central corneal thickness deformation variable information to the data analysis terminal to obtain the intraocular pressure data of the bionic eye, and correct the reading of the non-contact tonometer. The human eye simplified AI model is obtained based on image recognition neural network deep learning method, first set observation points on the cornea, under normal intraocular pressure, take a photo of the central cornea, when the intraocular pressure rises, take another photo of the central cornea, the observation points in the photos are offset, these offsets are used as the basis for neural network learning and discrimination, and the intraocular pressure situation is accurately fed back by analyzing the thickness change images of the central cornea before and after the intraocular pressure changes; The intraocular pressure deformation variable detection device includes a fixed base, a liquid injection metering pump and a data analysis terminal, the fixed base is provided with a bionic eye positioning groove, the bottom of the groove is provided with a heater and water supply channels and drainage channels, the water supply channels are connected with the liquid injection metering pump through pipelines, the drainage channels are connected with the pressure test cavity, the pressure test cavity is provided with a pressure sensor, the fixed base is provided with a temperature sensor, and the pressure sensor and the temperature sensor are connected with the data analysis terminal through data cables respectively.

2. The non-contact visual calibration method of intraocular pressure according to claim 1, wherein, The top of the water supply channel is connected with the bottom center of the bionic eye through a liquid distribution sheet, the upper surface of the liquid distribution sheet is provided with a micro-hole array, the size of the micro-holes is 0.1-0.3mm, the distance between adjacent holes is 10-18 degrees, and there are 20-36 holes in total.

3. The non-contact visual calibration method of intraocular pressure according to claim 1, wherein, The top end of the drainage channel is connected with the bottom periphery of the bionic eye, the bottom end of the drainage channel is connected with the pressure test cavity through a collecting pipe, and the bottom of the pressure test cavity is provided with an emptying valve.

4. The non-contact visual calibration of intraocular pressure method of claim 1, wherein, The distribution of the observation points adopts geographical coordinate system, the latitude and longitude division accuracy is 0.1-0.5mm, and the division line is ablated on the surface of the cornea of the bionic eye by a laser marking machine.

5. The non-contact visual calibration of intraocular pressure method of claim 1, wherein, The electron microscope is a scanning electron microscope or a confocal microscope.

6. The non-contact visual calibration of intraocular pressure method of claim 1, wherein, The bionic eye is a hydrogel artificial eye or a "bionic eye" of Retina Implant AG, Germany; the pressure sensor is a MEMS pressure sensor; the intraocular pressure deformation variable detection device is 3D printed, the heater is a hollow structure, the heater is filled with heating electric oil, after the heating electric oil is baked, dried and solidified, the two wires are connected with the power supply, and the power is 4-10W.

7. The non-contact visual calibration of intraocular pressure method of claim 1, wherein, The artificial aqueous humor is a mixed solution of normal saline and sodium bicarbonate, wherein the concentration of normal saline is 125 mmol / L, and the concentration of sodium bicarbonate is 24 mmol / L. The artificial aqueous humor is a mixed solution of normal saline and sodium bicarbonate, wherein the concentration of normal saline is 125 mmol / L, and the concentration of sodium bicarbonate is 24 mmol / L.

8. The non-contact visual calibration of intraocular pressure method of claim 1, wherein, The operation process of the liquid injection metering pump in step 3 is as follows: 1) The simulated aqueous humor is injected with... Inject the artificial aqueous humor into the fixed base at a speed of cm / s. Once the fixed base is filled with artificial aqueous humor, record the injection time, corneal deformation information, and pressure value. 2) While ensuring that the overall injection time remains unchanged, increase the injection speed by 1% and record the corneal deformation information and pressure value. 3) Stop the injection when the pressure reaches the upper limit of high intraocular pressure, 30 mmHg.

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