Intelligent color-changing contact lens diagnosis system capable of synchronously monitoring intraocular pressure and body temperature

Abstract

The invention discloses an intelligent color-changing contact lens diagnosis system capable of synchronously monitoring intraocular pressure and body temperature, and is applied to the technical field of eye health monitoring. Comprising a composite substrate based on PDMS and pHEMA, an intraocular pressure sensor and a body temperature sensor which are jointly integrated in the composite substrate, a photochromic material and a thermochromic material which are contained in the composite substrate, and a periodic micro-column array which is constructed on the surface of the lens and is used for diagnosing intraocular pressure and body temperature abnormity based on a structural color visualization principle. Real-time synchronous high-precision non-invasive monitoring of intraocular pressure and body temperature is achieved, visual and visual diagnosis is achieved by means of structural color change of the periodic micro-column array, the composite substrate has good biocompatibility and long-term stability, and a non-invasive, real-time and convenient solution is provided for early diagnosis of eye diseases.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of eye health monitoring, in particular to an intelligent color-changing contact lens diagnosis system for monitoring intraocular pressure and body temperature synchronously. BACKGROUND

[0002] As the second largest cause of blindness in the world, glaucoma is closely related to abnormal fluctuations in intraocular pressure (IOP), and high intraocular pressure can cause irreversible damage to the optic nerve. Abnormal ocular surface temperature is directly related to inflammatory diseases such as dry eye and keratitis, and the ocular surface temperature of healthy people usually maintains at 31-37℃. Early and accurate monitoring of intraocular pressure and body temperature is crucial for the diagnosis and intervention of eye diseases. Traditional intraocular pressure measurement (such as Goldmann tonometer) can only be measured once, cannot reflect the diurnal fluctuation, is easily affected by ocular surface temperature (10℃ temperature difference can cause 87% error), and also has the risk of invasive contact. Existing devices also cannot achieve synchronous non-invasive monitoring of intraocular pressure and body temperature. Therefore, the development of a synchronous monitoring system with high sensitivity, biocompatibility and visualization function is of great clinical value to fill the gap in eye disease monitoring and protect eye health.

[0003] Therefore, the United Arab Emirates Khalifa University developed a color-changing contact lens based on pHEMA, which realized ultraviolet protection and temperature response, but had no intraocular pressure monitoring function; Harvard University integrated glucose and temperature sensors using MoS2 transistors, relying on complex wireless circuits, but the cost was high; the implantable intraocular pressure telemetry system of the United States Konigsberg Instruments company can monitor intraocular pressure for 24 hours, but needs to be surgically implanted and is a invasive operation. The intelligent lens developed by the Chinese Academy of Sciences Shenzhen Institute of Advanced Technology detects dry eye and high intraocular pressure through nanostructure color change, but the temperature response range exceeds the physiological interval, and the practicality is limited.

[0004] It can be seen that the existing technology has the following problems: single function: existing intelligent contact lenses mostly only monitor a single parameter (such as only temperature or only intraocular pressure), which cannot meet the synchronous monitoring needs of intraocular pressure and body temperature; complex operation: relying on complex electrical signal reading or wireless circuit design (such as the Harvard University solution), which is high in cost and not conducive to popularization; insufficient practicality: the temperature response range exceeds the physiological interval (such as the Chinese Academy of Sciences solution), which cannot accurately reflect the ocular surface temperature under normal physiological conditions; invasive risk: implantable systems require surgery and are not suitable for daily screening; obvious interference: traditional intraocular pressure measurement is greatly affected by temperature (10℃ temperature difference error reaches 87%).

[0005] Therefore, how to provide an intelligent color-changing contact lens diagnosis system capable of effectively solving the problems existing in the prior art, developing a synchronous monitoring system with high sensitivity, biocompatibility and visualization function, filling the blank of eye disease monitoring, and protecting eye health is a problem that those skilled in the art need to solve. SUMMARY

[0006] Therefore, the present application provides an intelligent color-changing contact lens diagnosis system for synchronous monitoring of intraocular pressure and body temperature.

[0007] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0008] An intelligent color-changing contact lens diagnosis system for synchronous monitoring of intraocular pressure and body temperature comprises a composite substrate based on PDMS and pHEMA, an intraocular pressure sensor and a body temperature sensor collectively integrated in the composite substrate, a photochromic material and a thermochromic material contained in the composite substrate, and a periodic micro-column array constructed on the surface of the lens for diagnosing abnormal intraocular pressure and body temperature based on the principle of structural color visualization.

[0009] Optionally, the composite substrate based on PDMS and pHEMA specifically comprises:

[0010] PDMS as the bottom layer of the composite substrate; the intraocular pressure sensor and the body temperature sensor are fixed to the surface of the PDMS and adopt silver paste connecting electrodes; pHEMA as the upper layer of the composite substrate is combined with the bottom layer and encapsulates the intraocular pressure sensor and the body temperature sensor therein; wherein the pHEMA contains the photochromic material and the thermochromic material.

[0011] Optionally, the intraocular pressure sensor selects a micro-spiral LCR resonator.

[0012] Optionally, the body temperature sensor selects a flexible thermocouple sensor and adopts a serpentine wiring design.

[0013] Optionally, the photochromic material adopts spiropyran derivatives as the photochromic core and prepares photochromic microcapsules with a core-shell structure through an emulsion polymerization method.

[0014] Optionally, the thermochromic material selects fluoran-based thermochromic dyes and improves the compatibility with pHEMA through a graft modification method.

[0015] Optionally, it further comprises an NFC coil integrated in an external frame glasses, which is used to transmit the resonant frequency signal of the intraocular pressure sensor to the terminal device based on the electromagnetic coupling mode, calculate the intraocular pressure value through the frequency difference of the double resonators, and establish a multiple regression compensation equation based on the body temperature data collected by the body temperature sensor, further optimize the measurement result of the intraocular pressure value based on the mutual relationship between the intraocular pressure and the body temperature.

[0016] Compared with the prior art, the intelligent discoloration contact lens diagnostic system for monitoring intraocular pressure and body temperature synchronously is provided. The real-time and synchronous non-invasive monitoring of intraocular pressure and body temperature is realized by integrating a dual-mode sensor, wherein the intraocular pressure sensitivity is 0.85 MHz / mmHg, the temperature response sensitivity is 8% / ℃, and the response time is less than 30 seconds. The temperature interference is effectively eliminated by means of a dual-resonator coupling design, the error under a 10℃ temperature difference is reduced from 87% to 7%, and the error after compensation of the dual-resonator is stabilized at ±1.5 mmHg, meeting the clinical precision requirements. The bionic structural color visualization mechanism is used to intuitively reflect the parameter abnormalities by means of the micro-column array structural color change (blue light-green light-yellow light), and the naked-eye diagnosis without complex equipment is realized. The PDMS / pHEMA composite substrate is adopted, which has good oxygen permeability (the DK value of PDMS is greater than or equal to 100) and mechanical flexibility (the elastic modulus of pHEMA is 0.3-0.5 MPa), and the good biocompatibility and long-term stability are verified by experiments, thereby providing a non-invasive, real-time and convenient solution for early diagnosis of eye diseases. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative labor on the basis of the provided drawings.

[0018] Figure 1 The system structure schematic diagram provided by the present application is shown. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0020] Embodiment 1:

[0021] Embodiment 1 of the present application discloses an intelligent discoloration contact lens diagnostic system for monitoring intraocular pressure and body temperature synchronously, as shown in Figure 1As shown, including: based on PDMS and pHEMA composite substrate, integrated in the composite substrate together eye pressure sensor and body temperature sensor, contained in the composite substrate photochromic material and thermochromic material, constructed on the surface of the lens, for the diagnosis of periodic micro column array based on structural color visualization principle of eye pressure and body temperature abnormalities.

[0022] The flexible substrate and packaging process of the contact lens are crucial to the performance of the sensor and the comfort of wearing. The present application selects the composite system of PDMS and pHEMA as the substrate material, which combines the good oxygen permeability (DK value ≥ 100) of PDMS and the mechanical flexibility (elastic modulus 0.3-0.5MPa) of pHEMA. Through the hierarchical curing process, the curved conformal integration of the sensor and the substrate is realized. First, a bottom layer of PDMS with a thickness of 200μm is prepared to provide stable mechanical support for the entire contact lens. Then, on the bottom layer of PDMS, a top layer of pHEMA with a thickness of 100μm is prepared by ultraviolet light-induced polymerization, and the sensor is packaged therein. During the packaging process, plasma treatment technology is used to treat the packaging interface, enhancing the bonding force between the sensor and the substrate and ensuring that the sensor will not fall off during long-term wearing.

[0023] The composite substrate based on PDMS and pHEMA, specifically:

[0024] The present application adopts the hierarchical casting method to prepare the composite substrate based on PDMS and pHEMA, which fully utilizes the good oxygen permeability of PDMS and the mechanical flexibility of pHEMA, and provides a stable support structure for the integration of the sensor and the realization of the function of the contact lens.

[0025] PDMS as the bottom layer of the composite substrate: mix the PDMS prepolymer with the curing agent at a mass ratio of 10:1, stir thoroughly, and make them fully contact and crosslink. Then, pour the mixed PDMS into a mold with a radius of curvature of 8mm, which simulates the corneal curvature of the human eye in shape and size, ensuring that the prepared contact lens better fits the surface of the eyeball. Cure in a 60℃ oven for 2 hours to form an elastomer with certain strength and flexibility, providing stable mechanical support for the entire contact lens.

[0026] Fixing the intraocular pressure sensor and the body temperature sensor on the PDMS surface: The intraocular pressure sensor and the body temperature sensor are fixed on the PDMS surface. The LCR resonator is used to detect the change of intraocular pressure, and the thermocouple sensor is used to measure the temperature of the ocular surface. The synchronous monitoring of intraocular pressure and body temperature is realized by the cooperation of the two. Silver paste is used to connect the electrodes. The silver paste has good conductivity, which can ensure the stable and reliable signal transmission between the sensor and the external circuit. During the connection process, the amount and application position of the silver paste need to be strictly controlled to avoid short circuit or poor contact and other problems.

[0027] pHEMA as the upper layer of the composite substrate: The pHEMA monomer solution containing photochromic and thermochromic materials (HEMA:EGDMA = 95:5, w / w) is cast on the surface of the sensor. Among them, EGDMA acts as a crosslinking agent, which can make the pHEMA monomer crosslinking reaction, form a three-dimensional network structure, and improve the mechanical properties and stability of the material. Under the irradiation of ultraviolet light (365 nm, 10 mW / cm 2 ), it is cured for 10 minutes. Ultraviolet light initiates the polymerization reaction of pHEMA monomer, making the upper layer of pHEMA tightly combined with the bottom layer of PDMS, and at the same time, the sensor is packaged in it, protecting the sensor from the external environment.

[0028] The prepared lens is soaked in PBS solution for 24 hours. The PBS solution has similar pH and ionic strength to the human physiological environment, which can simulate the actual use environment of contact lenses on the ocular surface. During the soaking process, the PBS solution can remove unreacted monomers and impurities in the lens, improve the biocompatibility and safety of the lens, and ensure the eye health of the wearer.

[0029] The intraocular pressure sensor selects a micro-spiral LCR resonator, whose working principle is based on the piezoresistive effect. When the intraocular pressure changes, the cornea will produce a slight deformation, which will be transmitted to the LCR resonator, causing a change in its inductance value, and then causing a shift in the resonance frequency. The resonator is composed of a copper coil with a diameter of 50 μm and a 0.1 μm thick PDMS diaphragm. Through optimization design, the experimental results show that its sensitivity is as high as 0.85 MHz / mmHg, and the linear range is 5-30 mmHg, which can accurately perceive the change of intraocular pressure in the normal physiological range.

[0030] The body temperature sensor uses a flexible thermocouple sensor composed of a copper-constantan thin film pair with a diameter of 20μm. Thermocouple sensors operate based on the Seebeck effect. When a temperature difference exists between the two ends of the sensor, a thermoelectric potential is generated. The temperature is determined by measuring the magnitude of the thermoelectric potential. To ensure that the sensor fits tightly against the skin of the eye surface and achieves fast and accurate temperature acquisition, the sensor uses a serpentine wiring design. This design not only increases the contact area between the sensor and the eye surface, but also improves the sensor's flexibility. The entire sensor is less than 50μm thick, has a response time of less than 5 seconds, and a resolution of up to 0.1°C, meeting the needs of real-time, high-precision monitoring of ocular surface temperature.

[0031] The color change diagnostic mechanism of the present invention is based on the principle of structural color visualization, and color control is achieved by constructing a periodic micro-pillar array on the lens surface. The period of the micro-pillar array is 200-400nm and the height is 150nm. This nano-scale structural design can use the Bragg diffraction principle of light to reflect light of specific wavelengths. Under normal physiological conditions, that is, when the intraocular pressure is between 10-21mmHg and the temperature is between 33-38℃, the structure of the micro-pillar array causes the lens to mainly reflect blue light (450nm), at which time the lens appears blue. When the intraocular pressure rises above 21mmHg, the pressure on the cornea increases, causing the structural spacing of the micro-pillar array to increase. According to the Bragg diffraction formula, the lens's reflection of green light (550nm) is enhanced, and the lens color changes to green, intuitively indicating abnormally elevated intraocular pressure. When the ocular surface temperature is abnormal, above 37.5℃ or below 35.5℃, the structure of the micro-pillar array will change due to the thermal expansion characteristics of the material, causing the structural color to shift and the lens to display a yellow warning, reminding the user that the ocular surface temperature is abnormal. This visual diagnostic mechanism based on structural color changes does not require complex instruments and equipment. Users and doctors can quickly understand abnormalities in intraocular pressure and body temperature by observing changes in lens color with the naked eye, achieving convenient and intuitive health monitoring.

[0032] Photochromic materials are a key component in enabling visual diagnostics in smart photochromic contact lenses. Their performance directly impacts the lens's sensitivity to ambient light changes and the accuracy of its color changes. This invention utilizes spiropyran derivatives as the photochromic core and prepares core-shell photochromic microcapsules via emulsion polymerization. This approach aims to improve the stability and dispersibility of the photochromic material, enabling it to better bond with the contact lens base material and achieve efficient photochromic functionality. The specific preparation process is as follows:

[0033] First, 1g of spiropyran was dissolved in 10mL of cyclohexane and stirred thoroughly to completely dissolve it, forming a uniform oil-phase solution. Cyclohexane, as a good organic solvent, effectively dissolves spiropyran, providing a stable reaction environment for subsequent reactions. Then, 5mL of a 10% aqueous solution of melamine formaldehyde prepolymer was added, resulting in a water-in-oil emulsion. The reaction was stirred continuously in a constant-temperature water bath at 60°C for 4 hours. During this process, the melamine formaldehyde prepolymer gradually polymerized in the aqueous phase, forming a three-dimensional network structure that encapsulated the spiropyran, ultimately forming core-shell microcapsules with a diameter of 1-3μm. This microcapsule structure effectively protected the spiropyran from the external environment, improving the stability and durability of its photochromic properties.

[0034] In order to verify the successful preparation of microcapsules, Fourier transform infrared spectroscopy (FTIR) was used to characterize them. The FTIR spectrum showed that at 3355 cm -1 The NH stretching vibration peak appeared at 1731 cm, which is the characteristic peak of amino groups in melamine formaldehyde resin, indicating that melamine formaldehyde resin successfully participated in the formation of microcapsules. -1 The C=O stretching vibration peak at further confirms the presence of carbonyl groups in the microcapsules, which is consistent with the structural characteristics of melamine formaldehyde resin. The appearance of these characteristic peaks fully demonstrates the successful preparation of photochromic microcapsules with a core-shell structure through emulsion polymerization.

[0035] Thermochromic materials play an important role in smart color-changing contact lenses. They can change color according to changes in ocular surface temperature, providing an intuitive temperature change indicator for simultaneous monitoring of intraocular pressure and body temperature. However, traditional thermochromic dyes have poor compatibility with polyhydroxyethyl methacrylate (pHEMA) substrate materials commonly used in contact lenses, which limits their application in contact lenses. To solve this problem, the present invention uses fluoran thermochromic dyes and improves their compatibility with pHEMA through grafting modification. The specific improvement process is as follows:

[0036] fluoran was dissolved in 10 mL of dimethyl sulfoxide (DMSO), which is a strong polar organic solvent that can well dissolve fluoran and make it uniformly dispersed in the reaction system. Then, 2 mL of hydroxyethyl methacrylate was added, which is a monomer containing a double bond that can undergo grafting reaction with fluoran, thereby introducing fluoran into the polymer chain. Under the action of initiator azobisisobutyronitrile (AIBN, 0.1 g), the polymerization reaction was carried out at 60°C for 2 hours. AIBN can decompose to produce free radicals under heating conditions, which can initiate the grafting polymerization reaction between hydroxyethyl methacrylate and fluoran. Through this method, a thermochromic monomer with a grafting rate of 35% was successfully obtained. The increase in grafting rate indicates that effective grafting reaction has occurred between fluoran and hydroxyethyl methacrylate, which will greatly improve the compatibility of thermochromic dye with pHEMA.

[0037] In order to determine whether the phase transition temperature of the modified thermochromic monomer meets the physiological monitoring requirements, differential scanning calorimetry (DSC) was used for testing. The DSC test results show that the phase transition temperature of the modified thermochromic monomer is 37°C, which matches the normal physiological temperature range of the human body and can accurately reflect the changes in the ocular surface temperature. Under normal physiological conditions, the ocular surface temperature is close to 37°C, at which time the thermochromic monomer is in a stable state and the lens presents a specific color. When the ocular surface temperature changes abnormally, the molecular structure of the thermochromic monomer will change, causing changes in its light absorption and emission properties, thereby causing the lens color to change, directly indicating the abnormal condition of the ocular surface temperature.

[0038] In order to realize effective processing and transmission of sensor signals, an NFC coil integrated in the external frame glasses is further included, with a coil diameter of 10 mm and 50 turns. The resonant frequency signal of the tonometer sensor is transmitted to a terminal device such as a smart phone or tablet based on an electromagnetic coupling method. An algorithm is built in the terminal device to calculate the intraocular pressure value through the double-resonator frequency difference (the traditional intraocular pressure measurement method often produces a large error when the temperature changes, while the differential calculation method based on the low-frequency (10-50 MHz) and high-frequency (100-200 MHz) LCR resonators in the present application significantly reduces the error from 87% to 7% under a 10℃ temperature difference, greatly improving the accuracy and stability of intraocular pressure measurement), and by analyzing the response of the resonator at different frequencies, the interference of environmental factors on intraocular pressure measurement can be effectively eliminated, improving the accuracy of measurement. At the same time, combined with the body temperature data collected by the body temperature sensor, a multiple regression compensation equation is established, based on the mutual relationship between intraocular pressure and body temperature, to further optimize the measurement result of the intraocular pressure value. The system outputs the corresponding discoloration diagnosis result according to the calculated real-time physiological parameters, and presents it to the user in an intuitive way. The power consumption of the whole system is less than 1 mW, and it can work continuously for 72 hours after one charge, meeting the needs of users for daily wear and monitoring.

[0039] In order to comprehensively evaluate the performance of the intelligent discoloration contact lens diagnosis system under different intraocular pressure and temperature conditions, a pig cornea model was used for intraocular pressure-temperature coupling response test. The pig cornea has high similarity in structure and physiological characteristics to the human cornea, with a thickness of about 500 μm, which can better simulate the human eye environment. The pig cornea model was placed in a 37℃ constant temperature box, which is close to the normal physiological temperature of the human body, ensuring the physiological and authenticity of the experimental environment. In the constant temperature box, a precise pressure applying device was used to apply a pressure of 5-30 mmHg to the cornea model, which covers the normal intraocular pressure range and the abnormal intraocular pressure range that may occur in diseases such as glaucoma. At the same time, a high-precision temperature regulation device was used to accurately adjust the environmental temperature in the range of 25-40℃, simulating the changes of ocular surface temperature in different physiological and environmental states of the human body.

[0040] During the experiment, a network analyzer (Agilent E5071C) was used to accurately measure changes in the resonant frequency of the LCR resonator. This network analyzer has high-precision frequency measurement capabilities and can accurately capture subtle changes in the resonant frequency, providing reliable data support for accurate measurement of intraocular pressure. Simultaneously, a spectrometer (USB2000+) was used to record the structural color reflectance spectrum. This spectrometer covers the visible light range and provides a comprehensive and accurate analysis of the structural color changes of the lens. To ensure the reliability and accuracy of the experimental results, each set of experiments was repeated five times, and the average value was taken as the final result. By repeating the experiments multiple times, experimental errors can be effectively reduced, the credibility of the data can be improved, and the experimental results can be made more convincing and scientific.

[0041] Experimental results show that the error in IOP measurement using a single resonator shows a clear linear growth trend with increasing temperature, with a correlation coefficient (R²) reaching 0.98, indicating a high degree of linear correlation between the two. At 25°C, the error in IOP measurement using a single resonator is approximately ±3 mmHg. However, when the temperature rises to 40°C, the error increases dramatically to ±10 mmHg, seriously affecting the accuracy of IOP measurements. However, using dual resonators for compensation significantly reduces the error, stabilizing it within a ±1.5 mmHg range. This error level fully meets the stringent clinical requirement for IOP measurement accuracy of ≤2 mmHg.

[0042] Through in-depth analysis of the frequency shift curves at different temperatures, it can be found that at 37°C, the normal physiological temperature of the human body, for every 1 mmHg increase in intraocular pressure, the frequency of the low-frequency resonator will decrease by 0.85 MHz, while the frequency of the high-frequency resonator will increase by 0.12 MHz. This difference in frequency change provides a theoretical basis for eliminating temperature interference through difference calculation. By establishing a mathematical model between the frequency difference of the dual resonators and the intraocular pressure, the influence of temperature changes on the intraocular pressure measurement can be effectively eliminated, thereby achieving high-precision measurement of intraocular pressure. This dual-resonator coupling design utilizes the different characteristics of the different resonators' responses to temperature and pressure. Through clever algorithm processing, it greatly improves the stability and accuracy of intraocular pressure measurement in different temperature environments, laying a solid foundation for the application of smart photochromic contact lens diagnostic systems in complex environments.

[0043] The color change response characteristic is one of the key performance indicators of the intelligent photochromic contact lens diagnostic system. It is directly related to the system's ability to visually diagnose abnormal changes in intraocular pressure and body temperature. In order to further study the color change response characteristics of the lens, the lens was placed on a high-precision temperature control console with an accuracy of ±0.1°C, which can achieve precise control of the lens temperature. Under 365nm ultraviolet light (intensity 5mW / cm 2Under the irradiation of UV-A (320-400 nm) and UV-B (280-320 nm) light, which simulates the UV environment that the human body may be exposed to in daily life, the reflectance spectra of the lens under different pressure-temperature combinations are recorded.

[0044] The color change images of the lens are collected using a smartphone camera with a resolution of 12MP. The smartphone camera has high resolution and convenience, which can clearly record the subtle changes of the lens color. By analyzing the RGB values of the collected images, the discoloration threshold and response time of the lens are studied in depth. RGB values are important parameters for describing color. By analyzing the changes of RGB values, the starting point of color change (discoloration threshold) and the speed of color change (response time) can be accurately determined. This method based on smartphone camera and RGB value analysis has the advantages of simple operation and low cost, and can realize fast and accurate evaluation of the color change response characteristics of the lens, providing important data support for the performance optimization and clinical application of the system.

[0045] The structural color change threshold of the smart color-changing contact lens has a clear definition, which is crucial for accurately monitoring abnormal intraocular pressure and body temperature. When the intraocular pressure is ≥22 mmHg, the proportion of green light on the lens will increase rapidly, exceeding 60%, and the lens color will obviously change to green, directly indicating the increase of intraocular pressure. When the temperature is ≥37.5℃, the intensity of yellow light will increase by 30%, and the lens color will turn yellow, warning of abnormal temperature rise on the ocular surface. This color change threshold is determined based on a large amount of experimental data and clinical research, and can accurately reflect the abnormal situation of human physiological parameters.

[0046] The response time of the lens is one of the important indicators to measure its performance. The experimental results show that the response time of the lens is <30 seconds, among which the blue-green conversion time is 15 seconds and the blue-yellow conversion time is 22 seconds. This fast response capability enables the lens to respond at the first time when the physiological parameters change abnormally, providing timely warning for the user. When the intraocular pressure is 25 mmHg and the temperature is 38℃, the reflection peak red shifts from 450 nm to 550 nm, which is due to the increase of the micro-pillar array structure spacing caused by the increase of intraocular pressure. According to the Bragg diffraction principle, the wavelength of the reflected light changes. At the same time, the reflection intensity at 580 nm increases by 40%, which is caused by the thermal expansion of the material due to temperature rise, leading to the change of the micro-pillar array structure and enhancing the reflection of 580 nm wavelength light. These spectral changes are closely related to the color change of the lens, and through the analysis of the spectrum, the internal mechanism of the lens discoloration can be understood in depth, providing theoretical support for further optimizing the performance of the lens.

[0047] The various embodiments described in this specification are implemented in a progressive manner, each embodiment focusing on the differences from other embodiments, and the same or similar parts between embodiments can be mutually referred to. For the apparatus disclosed by the embodiments, since it corresponds to the method disclosed by the embodiments, the description is relatively simple, and the relevant parts can be referred to the description of the method part.

[0048] The above description of disclosed embodiments enables one of ordinary skill in the art to make or use the application. Various modifications to these embodiments will be readily apparent to those of ordinary skill in the art, and the generic principles defined herein can be applied to other embodiments without departing from the spirit or scope of the application. Therefore, the application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An intelligent color-changing contact lens diagnostic system for synchronously monitoring intraocular pressure and body temperature, characterized in that: include: A composite substrate based on PDMS and pHEMA, an intraocular pressure sensor and a body temperature sensor integrated into the composite substrate, a photochromic material and a thermochromic material contained in the composite substrate, and a periodic microcolumn array constructed on the surface of a lens for diagnosing abnormal intraocular pressure and body temperature based on the principle of structural color visualization.

2. The intelligent color-changing contact lens diagnostic system for synchronously monitoring intraocular pressure and body temperature according to claim 1, characterized in that: Composite substrate based on PDMS and pHEMA, specifically: The PDMS serves as the bottom layer of the composite substrate; the intraocular pressure sensor and the body temperature sensor are fixed to the surface of the PDMS, and the electrodes are connected using silver paste; the pHEMA serves as the upper layer of the composite substrate, combined with the bottom layer, and encapsulates the intraocular pressure sensor and the body temperature sensor therein; wherein the pHEMA contains a photochromic material and a thermochromic material.

3. The intelligent color-changing contact lens diagnostic system for synchronously monitoring intraocular pressure and body temperature according to claim 1, characterized in that: The intraocular pressure sensor uses a micro-spiral LCR resonator.

4. The intelligent color-changing contact lens diagnostic system for synchronously monitoring intraocular pressure and body temperature according to claim 1, characterized in that: The body temperature sensor uses a flexible thermocouple sensor and adopts a serpentine wiring design.

5. The intelligent color-changing contact lens diagnostic system for synchronously monitoring intraocular pressure and body temperature according to claim 1, characterized in that: The photochromic material adopts spiropyran derivatives as the photochromic core, and prepares photochromic microcapsules with a core-shell structure through emulsion polymerization.

6. The intelligent color-changing contact lens diagnostic system for synchronously monitoring intraocular pressure and body temperature according to claim 1, characterized in that: The thermochromic material is a fluoran thermochromic dye, and its compatibility with the pHEMA is improved by a grafting modification method.

7. The intelligent color-changing contact lens diagnostic system for synchronously monitoring intraocular pressure and body temperature according to claim 1, characterized in that: Also includes: The NFC coil integrated into the external frame glasses is used to obtain the resonant frequency signal of the intraocular pressure sensor based on electromagnetic coupling and transmit it to the terminal device. The intraocular pressure value is calculated by the frequency difference of the dual resonators, and a multivariate regression compensation equation is established in combination with the body temperature data collected by the body temperature sensor. Based on the relationship between intraocular pressure and body temperature, the measurement result of the intraocular pressure value is further optimized.

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