Fundus camera color space calibration device and preparation method thereof

Abstract

The invention provides a fundus camera color space calibration device and a preparation method thereof. The fundus camera color space calibration device comprises a prosthetic eye which comprises a semi-spherical anterior segment shell and a plurality of semi-spherical fundus shells which are detachably connected with the anterior segment shell; the plurality of color block groups are respectively arranged on the inner surfaces of the plurality of fundus shells in positions within the fundus view range, each color block group comprises a plurality of color blocks arranged in an array, the color blocks in each color block group are different from one another, and the color blocks in different color block groups are also different from one another; each color block is made of a dye having a white light reflection spectrum and a fluorescence emission spectrum. The preparation method of the fundus camera color space calibration device comprises the following steps of a preparation stage, a prosthesis eye and color block bearing plate modeling stage, a prosthesis eye and color block bearing plate preparation stage, a dye preparation stage, a color block forming stage, a component integration stage and a testing and optimizing stage.

Description

Technical Field

[0001] The present invention belongs to the technical field of camera color calibration, and in particular relates to a fundus camera color space calibration device and a preparation method thereof. Background Art

[0002] Fundus cameras are based on the principle of optical imaging. They use special optical systems and lighting devices to penetrate the anterior structure of the eyeball and clearly obtain images of the retina, optic nerve head, macula and other parts of the fundus. Artificial intelligence based on fundus camera data has made great progress in the field of ophthalmology. In terms of disease diagnosis, it can accurately detect the characteristics of retinal diseases such as diabetic retinopathy and retinal detachment, as well as glaucoma and macular degeneration, and grade the severity of the disease to assist doctors in determining the symptoms; in terms of disease monitoring, it can conduct long-term follow-up observations on chronic diseases such as hypertension, eye lesions caused by diabetes, and eye surgery recovery, helping doctors to adjust treatment plans in a timely manner; in medical research, it helps to explore the pathogenesis of eye diseases and provide intuitive and key image basis for drug efficacy evaluation, which is of great significance to ophthalmology clinical medicine and scientific research.

[0003] Fundus cameras from different manufacturers have different designs, which may lead to changes in color space. Some manufacturers may have differences in optical system design, light source selection, or image sensor configuration. For example, in the optical system, different lens coating technology and materials will affect the light transmission and color reproduction; if the color temperature and intensity of the light source are different, the color of the fundus image will appear cooler or warmer. Differences in the color sensing ability and sensitivity of the image sensor will also change the color space. This change in color space will have some negative effects: (1) It may cause doctors to make misjudgments during the diagnosis process. For example, for some subtle lesion features, such as the color changes of early lesions in the macular area, or the subtle differences in the color of retinal hemorrhages, the inaccurate presentation due to the change in color space will interfere with the doctor's judgment on the degree and type of the lesion, and thus affect the precise formulation of subsequent treatment plans; (2) In fundus image processing based on artificial intelligence, different color spaces of cameras will lead to domain differences in data sets, making the prediction effect of the model inconsistent between different data sets, limiting the generalization ability of the model, and thus affecting the widespread application of artificial intelligence based on fundus camera images in ophthalmic practice. To solve these problems, color correction needs to be performed in the data preprocessing stage. In addition, multispectral imaging technology has great application value in many fields because its spectral resolution is higher than RGB color imaging, and it can provide rich spectral information for understanding the characteristics and composition of objects. In order to solve the cost problem of multispectral imaging equipment, researchers have proposed a computational multispectral imaging method that can obtain fundus multispectral imaging data without imaging equipment. This method is based on the premise of fully calibrating the color space of the fundus camera. However, there is currently no device specifically used for fundus camera color space calibration. This is because the existing color calibration devices mainly have the following problems:

[0004] (1) Most of the existing color calibration devices are universal, such as Pantone, DicColor and X-rite color cards. X-rite color cards are widely used in the imaging field. X-rite ColorChecker Classic contains 24 natural colors, and X-rite ColorChecker Digital SG has 96 colors. They have the function of recording the color performance of the camera and the lighting conditions of the imaging environment, and can be used by photographers for color correction. However, in the application scenario of color fundus cameras, these universal devices have two obvious incompatibilities: on the one hand, due to the limitation of the field of view of the fundus camera, it is difficult to image all the color blocks of the universal standard color card at one time. Calibration using universal color cards requires multiple operations, which is cumbersome and error-prone. In addition, it is difficult to keep the lighting conditions consistent during multiple imaging, which can easily lead to inaccurate calibration; on the other hand, the focal plane of fundus imaging is a curved surface. Unlike conventional imaging, the flat standard color card will be distorted when applied to the fundus camera, resulting in inconsistent lighting intensity between the center of the field of view and the surrounding area.

[0005] (2) Existing color calibration devices are limited in the number of color blocks and can only be used for traditional linear calibration algorithms. For example, the common general-purpose X-rite color calibration device has a maximum of 96 color blocks, which can only meet the needs of traditional linear calibration algorithms. Traditional linear calibration algorithms are based on relatively simple mathematical models, with limited color restoration accuracy, and are difficult to adapt to today's high-precision and high-complexity processing requirements for fundus images. These limited color blocks cannot provide sufficient data support for more advanced deep learning algorithms, which in turn limits the improvement of color calibration effects and the performance of multispectral reconstruction algorithms.

[0006] (3) Existing color calibration devices can only be used for white light reflection imaging, and the application scenarios are relatively simple. In white light imaging applications, the camera collects the reflected light of the object being photographed. These general devices are designed based on this environment and are only suitable for this lighting mode. However, in the field of fundus imaging, fluorescence imaging and white light imaging are equally important, especially when observing some specific fundus lesions. Fluorescence imaging can highlight the characteristics of the lesions and assist doctors in making accurate diagnoses. However, since general color calibration devices do not use fluorescent dyes, they cannot effectively perform calibration in this mode. Summary of the invention

[0007] In order to solve the above-mentioned deficiencies of the prior art, an object of the present invention is to provide a fundus camera color space calibration device and a preparation method thereof.

[0008] To achieve the above object, the present invention adopts the following technical solutions:

[0009] <Option 1>

[0010] The present invention provides a fundus camera color space calibration device, which has the following characteristics, including: a prosthetic eye, comprising a front segment shell in a semi-spherical shape and a plurality of fundus shells which are detachably connected to the front segment shell and are in a semi-spherical shape; and a plurality of color block groups, which are respectively arranged on the inner surfaces of the plurality of fundus shells at positions within the fundus field of view, wherein each color block group comprises a plurality of color blocks arranged in an array, the color blocks in each color block group are different from each other, and the color blocks in different color block groups are also different from each other, and each color block is made of a dye having a white light reflection spectrum and a fluorescence emission spectrum.

[0011] In the fundus camera color space calibration device provided by the present invention, it can also have the following characteristics: it also includes: multiple color block carrier plates, corresponding to multiple color block groups respectively, wherein each color block carrier plate has a shape matching the inner surface of the fundus shell, the outer side surface is used to fit on the inner surface of the corresponding fundus shell, and multiple dye pools are formed on the inner side surface, which are arranged in an array and correspond to multiple color blocks in the corresponding color block groups respectively, and each color block is formed by a dye colored in the corresponding dye pool.

[0012] The fundus camera color space calibration device provided by the present invention may also have the following feature: wherein the shape of the dye pool is a concave cylindrical structure.

[0013] The fundus camera color space calibration device provided by the present invention may also have the following feature: wherein the dye is one or more of luminescent acrylic pigment, quantum dot pigment and fluorescent ceramic pigment.

[0014] The fundus camera color space calibration device provided by the present invention may also have the following feature: the front segment housing and the fundus housing are detachably connected by a sleeve connection, a threaded connection or an elastic snap connection.

[0015] <Option 2>

[0016] The present invention also provides a method for preparing a fundus camera color space calibration device, which has the following characteristics and comprises the following steps:

[0017] Step S1, a preparation stage, selecting materials and manufacturing tools for a prosthetic eye and a color block carrier plate, dye raw materials and preparation tools, and a spectrum measurement device; wherein the prosthetic eye comprises an anterior segment shell and a plurality of fundus shells that are detachably connected to the anterior segment shell, and a plurality of dye pools arranged in an array are provided on one side of the color block carrier plate;

[0018] Step S2, the prosthetic eye and color block carrier plate modeling stage, constructing an anterior segment shell model, a fundus shell model and a color block carrier plate model based on the anatomical structure data of the human eyeball;

[0019] Step S3, the prosthetic eye and color block carrier plate preparation stage, preparing an anterior segment shell according to the anterior segment shell model, preparing multiple fundus shells according to the fundus shell model, and preparing multiple color block carrier plates according to the color block carrier plate model;

[0020] Step S4, dye preparation stage, first, a plurality of primary color dyes are prepared using pigment raw materials; then, a plurality of complex color dyes are produced by mixing a plurality of primary color dyes according to a preset color formula; finally, a spectrum measurement device is used to measure the actual white light emission spectrum and fluorescence emission spectrum information of each dye;

[0021] Step S5, the color block forming stage, the multiple dyes prepared in step S4 are colored in each dye pool one by one, so as to obtain multiple color block groups;

[0022] Step S6, the component integration stage, firstly, a plurality of color block carrier plates with color block groups are respectively attached to the inner surfaces of a plurality of fundus shells at positions within the fundus field of view, and then the plurality of fundus shells with color block carrier plates and the front segment shells are integrated and installed, and inspected, thereby obtaining a fundus camera color space calibration device.

[0023] The method for preparing the fundus camera color space calibration device provided by the present invention may also have the following characteristics:

[0024] Step S7, testing and optimization stage, connect the fundus camera color space calibration device obtained in step S6 to the fundus camera, simulate the actual fundus imaging process to perform imaging test on each color block, and optimize and adjust the anterior segment shell model, fundus shell model, and color block carrier plate model according to the simulated imaging test results.

[0025] Compared with the prior art, the advantages of the present invention are: the present invention provides a dedicated and efficient fundus camera color space calibration device and a preparation method thereof, which can perform one-time imaging, avoid inconsistent lighting, no distortion and uneven lighting problems, and accurately calibrate colors; expand color blocks, add representative colors, provide sufficient data for deep learning algorithms, accurately calibrate colors, meet their high-precision requirements, and lay a data foundation for multi-spectral reconstruction algorithms; adapt to white light and fluorescence imaging, and realize dual-mode color calibration.

[0026] (1) Based on the construction of an artificial eye model that is proportional to the size of a human eyeball, a number of color blocks are set in the shell of the artificial eye fundus, and are distributed in an array in the fundus field of view. When using this device to calibrate the color of the fundus camera, all the color blocks of the fundus can be imaged at one time to avoid the problem of inconsistent lighting. At the same time, because the color blocks are distributed in the fundus of the artificial eye according to the imaging focal plane characteristics of the fundus camera, there is no field of view distortion and uneven lighting, which can provide accurate color calibration for the fundus camera.

[0027] (2) The number of color blocks has been expanded. Compared with traditional general-purpose devices, a variety of representative color blocks have been added. These rich color block combinations can provide sufficient data resources for deep learning algorithms. When using this device to calibrate the color of the fundus camera, it can provide accurate color calibration for the fundus camera to meet the needs of deep learning algorithms for high-precision color calibration, and also provide a data basis for high-precision multi-spectral reconstruction.

[0028] (3) It can be used for both white light and fluorescence imaging. Considering the fluorescence imaging requirements in fundus imaging, the device of the present invention has been optimized in design and material selection, and fluorescent dyes have been used to enable it to adapt to both white light and fluorescence imaging modes. During fluorescence imaging, the color blocks in the device can accurately emit fluorescence signals, ensuring that the camera can also obtain accurate fluorescence color information in this mode, thereby achieving color calibration of the dual-mode fundus camera. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a schematic diagram of the exploded installation of a fundus camera color space calibration device in an embodiment of the present invention;

[0030] Figure 2 is a schematic diagram of the three-dimensional structure of the front section housing in an embodiment of the present invention; and

[0031] Figure 3 It is a schematic diagram of the three-dimensional structure of a flat color block carrier plate in an embodiment of the present invention. DETAILED DESCRIPTION

[0032] The concept, specific structure and technical effects of the present invention will be further described below in conjunction with the accompanying drawings to fully understand the purpose, characteristics and effects of the present invention.

[0033] <Example>

[0034] like Figure 1 As shown, the fundus camera color space calibration device 10 provided in this embodiment includes a prosthetic eye, multiple color block carrier plates 13 and multiple color block groups (not shown in the figure), wherein the prosthetic eye includes an anterior segment shell 11 and multiple fundus shells 12.

[0035] like Figure 1 As shown, the front segment housing 11 is semi-spherical, and a pupil 111 is provided in the central portion thereof. In this embodiment, a mounting connection portion 112 for mounting to a fundus camera is provided on the side of the front segment housing 11.

[0036] like Figure 1 As shown, multiple fundus shells 12 are detachably connected to the front segment shell 11; each fundus shell 12 is semi-spherical. In this embodiment, the outer diameter of the prosthetic eye formed by the fundus shell 12 and the front segment shell 11 is 27.5 mm, the inner diameter is 23.5 mm, and the diameter of the pupil 111 is 8.0 mm.

[0037] In this embodiment, the front section housing 11 and the fundus housing 12 are detachably connected by a standard bayonet sleeve connection method, so as to facilitate the rapid replacement of the fundus housing 12 and reduce assembly errors. Specifically, a snap-on male buckle 113 is formed at the opening edge of the front section housing 11, and a snap-on female buckle 121 matching the snap-on male buckle 113 is formed at the opening edge of the fundus housing 12.

[0038] like Figure 1 As shown, multiple color block carrier plates 13 are arranged on the inner surfaces of multiple fundus shells 12 at positions within the fundus field of view; each color block carrier plate 13 has a shape that matches the inner surface of the fundus shell 12, and its outer side surface is used to fit on the inner surface of the corresponding fundus shell 12, and multiple dye pools 131 arranged in an array are formed on the inner side surface. This layout can make full use of the fundus imaging space, improve the color block collection efficiency, and can sensitively capture optical distortion. In this embodiment, each color block carrier plate 13 has 6×6 dye pools 131, and the shape of the dye pool 131 is a concave cylindrical structure with a diameter of 2 mm and a depth of 1 mm.

[0039] The plurality of color block groups correspond to the plurality of color block carrier plates 13 respectively; each color block group includes a plurality of color blocks corresponding to the plurality of dye pools 131 in the corresponding color block carrier plates 13. Each color block is formed by a dye having a white light reflection spectrum and a fluorescent emission spectrum colored in the corresponding dye pool 131; the color blocks in each color block group are different from each other, and the color blocks in different color block groups are also different from each other. In this embodiment, the dye is a luminescent acrylic pigment.

[0040] This embodiment also provides a method for preparing the above-mentioned fundus camera color space calibration device 10, and the preparation method includes the following steps S1-S7.

[0041] Step S1, the preparation stage, selects materials and manufacturing tools for the prosthetic eye and the color block carrier plate 13, dye raw materials and preparation tools, and spectrum measurement equipment.

[0042] In this embodiment, the prosthetic eye and the color block carrier plate 13 are prepared using a 3D printer, and photosensitive resin is selected as the 3D printing material. The photosensitive resin has a tensile strength range of 30-60MPa, a bending strength range of 50-90MPa, and a shrinkage range of 0.05-0.15%, so as to ensure fine structural molding during the 3D printing process and ensure that the dimensional accuracy of the components meets the design requirements.

[0043] The dye raw materials use 15-color luminous acrylic pigments as primary dyes, ranging from short-wave purple to long-wave red. The dye ingredients include fluorescent dye matrix, carrier resin and additives; among them, the fluorescent dye matrix uses rhodamine, fluorescein derivatives, bright yellow, dispersed fluorescent yellow, basic royal blue and thio-bright yellow pigment, etc., the carrier resin uses amino resin, benzoic melamine-formaldehyde resin, etc., and the additives use wetting dispersants, light stabilizers, antioxidants, etc. Strictly control the quality of raw materials, and the weighing accuracy of each component is ±0.001g to ensure that the primary color dye composition is accurate, and record the composition and configuration process. Preparation of dye preparation tools: equipped with a pipette with an accuracy of ±0.1μL, used to accurately measure the solvent to ensure the accurate ratio of the dye composition. Prepare a stirrer with temperature control function, the temperature control range is 20-60℃, and the stirring speed range is 500-2000rpm, which is used to evenly mix the dye and ensure the quality of the dye.

[0044] The spectral measurement instrument uses a high-resolution spectrum analyzer with a measurement wavelength range of 300-1100nm. It can accurately capture the spectral information of the color block and provide reliable data support for subsequent calibration.

[0045] Step S2, the prosthetic eye and color block carrier plate modeling stage, constructs an anterior segment shell model, a fundus shell model and a color block carrier plate model based on the anatomical structure data of the human eyeball.

[0046] Specifically, the Solidworks software is used to construct the anterior segment shell model, the fundus shell model and the color block carrier plate model respectively according to the human eyeball anatomical structure data. The tolerance of the standard bayonet connecting the anterior segment shell 11 and the fundus shell 12 is controlled within ±0.05mm to ensure the interface accuracy and stability.

[0047] According to the distribution and size of the color blocks, the dye pool 131 in the color block carrier plate 13 is designed. The shape of the color block carrier plate 13 fits the inner surface of the fundus housing 12, and the volume of a single dye pool 131 is about 3.14 μL, ensuring uniform filling of the dye.

[0048] In this embodiment, a plane color block carrier plate model is constructed based on the anatomical data of the human eyeball, and a plane color block carrier plate 14 (see Figure 3 ) in the dye pool 141, the specification of the dye pool 141 is the same as that of the dye pool 131 in the color block carrier plate 13, and is used for color block spectral curve calibration to ensure that the quality of the carried dye is the same. The measured spectral curve can be used for calibration of the dye pool 131 in the color block carrier plate 13.

[0049] Step S3, the prosthetic eye and color block carrier plate preparation stage, prepares anterior segment shell 11 according to the anterior segment shell model, prepares multiple fundus shells 12 according to the fundus shell model, and prepares multiple color block carrier plates 13 according to the color block carrier plate model.

[0050] Specifically, the designed anterior segment shell model, fundus shell model, color block carrier plate model and plane color block carrier plate model were imported into a professional 3D printer, and the printing layer thickness was set to 0.05-0.2mm to ensure the dimensional accuracy and surface quality of the printed parts.

[0051] A higher resolution printing mode is used for printing the color block carrier plate 13 and the flat color block carrier plate 13, with a layer thickness of 0.05-0.1 mm. After printing, a three-coordinate measuring machine is used to check the dimensional deviation, and the deviation is controlled within ±0.1 mm, which meets the design tolerance requirements.

[0052] Step S4, dye preparation stage, first, a plurality of primary color dyes are prepared using pigment raw materials; then, a plurality of complex color dyes are produced by mixing a plurality of primary color dyes according to a preset color formula; finally, a spectral measurement device is used to measure the actual white light reflectance spectrum and fluorescence emission spectrum information of each dye.

[0053] Specifically, the primary dye is prepared by adding the raw materials into a container and stirring them for 1-3 hours using a stirrer with a rotation speed of 1000-3000 rpm to fully mix the raw materials. For insoluble raw materials, an organic solvent can be appropriately added to assist dissolution, and the amount of the auxiliary solvent is 5-15% of the total mass of the raw materials.

[0054] Preparation of complex dyes: According to the preset color formula, the prepared primary dyes are mixed to generate complex dyes. The amount of primary dyes added is precisely controlled, and the addition speed is 0.1-0.5mL / min. The mixture is mixed in real time according to the set ratio, and the ingredients and configuration process are recorded. Application of mixing technology: During the mixing process, high-speed stirring (stirring speed is 1500-3500rpm) and ultrasonic vibration (frequency is 20-50kHz, power is 100-500W) technology are used for a duration of 15-60 minutes to ensure that the primary dyes are fully and evenly mixed to avoid color group agglomeration.

[0055] Coloring the flat color block carrier plate with a dye pool: Since acrylic dye has a high viscosity and is difficult to color with a pipette, this embodiment adopts a dilution + repeated coloring process, using alcohol to dilute the dye 5 times. During the dilution process, high-speed stirring (stirring speed is 1500-3500rpm) and ultrasonic oscillation (frequency is 20-50kHz, power is 100-500W) technology are used to ensure that the dye is fully and evenly diluted to avoid color group agglomeration.

[0056] The prepared dye is slowly injected into the dye pool 141 of the flat color block carrier plate 14 with a pipette, and the single injection volume is 1.0 μL, ensuring that the dye evenly covers the bottom of the pool without bubbles or flow marks. After the single injection is completed, dry it for 30 minutes to allow the alcohol to fully evaporate and make the dye thickness uniform. Repeat the above operation until all the diluted dye is transferred to the dye pool. During the coloring process, if there is unevenness, take remedial measures such as local refilling or re-coloring in time.

[0057] Spectral curve measurement: (1) Reflectance spectrum measurement: a high-precision spectrum analyzer is used to measure the reflectance spectrum curve of the sample after coloring the plane dye pool. The measurement environment temperature is controlled at 20-25°C, the humidity is controlled at 40-60%, and the measurement wavelength range is 300-1100nm to obtain the reflectance data of the sample at different wavelengths; (2) Fluorescence spectrum measurement: the fluorescence spectrum is measured under short-wave illumination (wavelength of 365-390nm) with a measurement wavelength range of 400-800nm, and the fluorescence emission peak position and intensity are recorded; (3) RGB value calibration calculation: a high-performance RGB camera (resolution of 10-20MP) is used to synchronously image the color block in the dye pool 141 and the standard color card (X-rite ColorChecker Digital SG), and the conversion matrix is ​​calculated by the standard color card RGB value captured by the camera and the standard RGB value. The standard RGB value of the dye is calculated as the true RGB value, and the calculation error is controlled within ±5%.

[0058] In step S5, the color block forming stage, the multiple dyes prepared in step S4 are colored in each dye pool 131 one by one, so as to obtain multiple color block groups.

[0059] Specifically, the prepared dye is slowly injected into the dye pool 131, and the injection process is the same as the coloring process of the dye pool 141. After coloring, the color block carrier plate 13 is dried in a well-ventilated environment for 24-48 hours to ensure that the dye is completely cured.

[0060] Step S6, the component integration stage, firstly, a plurality of color block carrying plates 13 with color block groups are respectively attached to the inner surfaces of a plurality of fundus shells 12 at positions within the fundus field of view, and then the plurality of fundus shells 12 with the color block carrying plates 13 and the front segment shell 11 are integrated and installed, and inspected, thereby obtaining the fundus camera color space calibration device 10.

[0061] Specifically, the plurality of color block carriers 13 with the color block groups and the fundus housing 12 are first integrated, the bonding firmness of the color block carrier 13 and the fundus housing 12 is checked, and a pulling force of 5-10N is applied to ensure that the color block carrier 13 will not shift. Then, the plurality of fundus housings 12 with the color block carriers 13 and the front section housing 11 are integrated and installed. Finally, a comprehensive appearance inspection is performed on the integrated device to remove surface dust, debris, etc.

[0062] Step S7, testing and optimization stage, connect the fundus camera color space calibration device 10 obtained in step S6 to the fundus camera, simulate the actual fundus imaging process to perform imaging test on each color block, and optimize and adjust the anterior segment shell model, fundus shell model, and color block carrier plate model according to the simulated imaging test results.

[0063] Specifically, (1) simulated imaging test, connect the fundus camera color space calibration device 10 to the fundus camera, simulate the actual fundus imaging process, and simulate the actual fundus imaging process to perform imaging test on each color block. Observe whether there is visual field distortion caused by model preparation (distortion rate is controlled within ±2%), check whether the color block exceeds the visual field range (visual field coverage reaches more than 95%), and check whether there is light leakage and uneven lighting (light uniformity reaches more than 90%).

[0064] (2) Optimization and adjustment: optimize and adjust the anterior segment shell model, fundus shell model, and color block carrier plate model according to the simulated imaging test results. For example, for areas with visual field distortion, modify the 3D model parameters to correct them; for areas with uneven lighting, adjust the dye pool structure or replace the light source to ensure that the calibration device performs optimally.

[0065] The above-mentioned embodiments are preferred examples of the present invention and are not intended to limit the protection scope of the present invention.

[0066] For example, in the above-mentioned embodiment, the anterior segment shell, the fundus shell and the color block carrier plate in the calibration device are prepared by 3D printing process. However, in the present invention, the anterior segment shell, the fundus shell and the color block carrier plate can also be prepared by traditional machining combined with a mold forming process, a composite material forming process, an additive manufacturing process - selective laser sintering (SLS), or a micromachining technology - a process combining photolithography and etching.

[0067] (1) Traditional machining combined with mold forming: First, according to the design drawings of the anterior segment shell and the fundus shell, use CNC machine tools and other equipment to perform milling, turning, drilling and other processing operations on metal or plastic materials to preliminarily produce the approximate shape of the component. Then, for some parts with complex curved surfaces or fine structures, the mold forming process is adopted. Make a high-precision mold, put the preliminarily processed component blank into the mold, and form it into the final desired shape through injection molding (for plastic materials) or die casting (for metal materials). Finally, the molded component is surface treated, such as grinding and polishing, to meet the surface quality requirements.

[0068] (2) Composite material molding process: Select suitable composite materials, such as carbon fiber reinforced composite materials. First, lay the reinforcing fibers (carbon fibers, etc.) in the mold according to the design requirements, and then inject the matrix materials such as resin to make them infiltrate the fibers and solidify them under certain temperature and pressure conditions. For the connection parts in the front segment shell and the fundus shell, the connectors can be pre-embedded during the laying process or secondary processing and installation can be performed after molding. Surface treatment is also required after molding to ensure surface flatness and smoothness.

[0069] (3) Additive manufacturing process - Selective Laser Sintering (SLS): First, prepare suitable powder materials, such as nylon powder. Spread the powder evenly on the workbench, and then use a high-energy laser beam to selectively sinter the powder layer according to the three-dimensional model data of the anterior segment shell and the fundus shell, so that the powder particles melt and bond together under the action of laser energy to form a solid structure. After completing the sintering of one layer, the workbench is lowered by a layer thickness, and a new layer of powder is spread on it. The above sintering process is repeated, and the layers are stacked layer by layer until the entire component is manufactured. Finally, the sintered components are post-processed, such as removing excess powder and surface polishing, to improve the surface quality.

[0070] (4) Micromachining technology - photolithography and etching combined process: First, a layer of photoresist is coated on the surface of a substrate material such as a silicon wafer, and then the designed anterior segment shell or fundus shell pattern is transferred to the photoresist through mask lithography. Next, an etching process (such as chemical etching or plasma etching) is used to remove the substrate material not protected by the photoresist to form the desired structural shape. Finally, the photoresist is removed and necessary surface treatment and cleaning steps are performed.

[0071] For example, in the above embodiment, the dye uses luminescent acrylic pigment. However, in the present invention, the dye can also use quantum dot pigment or fluorescent ceramic pigment. Quantum dot is a nano-scale semiconductor material with unique optical and electronic properties. Its fluorescence emission wavelength can be precisely controlled by adjusting the particle size, and a wide spectrum coverage from visible light to near-infrared light can be achieved. In the preparation process, the quantum dots are dispersed in a suitable matrix material (such as a polymer or glass) to form a stable fluorescent coating or dye solution for the production of fundus color blocks. Quantum dot fluorescent dyes have the advantages of narrow emission spectrum, high brightness and good light stability, and can provide more accurate fluorescent color information, especially suitable for application scenarios with high requirements for fluorescence imaging accuracy. Fluorescent ceramics are a material that combines fluorescent substances with ceramic matrices. For example, using alumina ceramics as a matrix and doping rare earth elements (such as europium, terbium, etc.) as activators, fluorescent ceramic materials with excellent fluorescent properties can be prepared. The preparation process includes mixing the raw material powders evenly, densifying them through a high-temperature sintering process, and forming fluorescent ceramic color blocks with a certain shape and size. During the sintering process, process parameters such as temperature, pressure and atmosphere need to be precisely controlled to ensure that the fluorescent material is evenly distributed in the ceramic matrix and achieve good fluorescent emission performance.

[0072] For example, in the above embodiment, the front section housing and the fundus housing are detachably connected by a sleeve connection. However, in the present invention, the front section housing and the fundus housing may also be detachably connected by a threaded connection or an elastic buckle connection.

Claims

1. A fundus camera color space calibration device, characterized in that: include: A prosthetic eye, comprising a hemispherical anterior segment shell and a plurality of hemispherical fundus shells which are detachably connected to the anterior segment shell; as well as A plurality of color block groups are respectively arranged on the inner surfaces of the plurality of fundus shells at positions within the fundus field of view, Each of the color block groups includes a plurality of color blocks arranged in an array. The color blocks in each color block group are different from each other, and the color blocks in different color block groups are also different from each other. Each of the color blocks is made of a dye having a white light reflection spectrum and a fluorescent emission spectrum.

2. The fundus camera color space calibration device according to claim 1, characterized in that: Also includes: A plurality of color block carrying plates, respectively corresponding to the plurality of color block groups, Each of the color block carrier plates has a shape that matches the inner surface of the fundus shell, an outer surface is used to fit on the inner surface of the corresponding fundus shell, and a plurality of dye pools arranged in an array and corresponding to the plurality of color blocks in the corresponding color block group are formed on the inner surface. Each of the color blocks is formed by dyes colored in the corresponding dye pool.

3. The fundus camera color space calibration device according to claim 2, characterized in that: in, The shape of the dye pool is a concave cylindrical structure.

4. The fundus camera color space calibration device according to claim 1 or 2, characterized in that: in, The dye is one or more of luminescent acrylic pigment, quantum dot pigment and fluorescent ceramic pigment.

5. The fundus camera color space calibration device according to claim 1, characterized in that: in, The front section shell and the fundus shell are detachably connected by a sleeve connection, a threaded connection or an elastic snap connection.

6. A method for preparing a fundus camera color space calibration device, characterized in that: The following steps are involved: Step S1, a preparation stage, selecting materials and manufacturing tools for a prosthetic eye and a color block carrier plate, dye raw materials and preparation tools, and a spectrum measurement device; wherein the prosthetic eye comprises a front segment shell and a plurality of fundus shells that are detachably connected to the front segment shell, and a side surface of the color block carrier plate has a plurality of dye pools arranged in an array; Step S2, the prosthetic eye and color block carrier plate modeling stage, constructing an anterior segment shell model, a fundus shell model and a color block carrier plate model based on the anatomical structure data of the human eyeball; Step S3, a prosthetic eye and a color block carrier plate preparation stage, preparing the anterior segment shell according to the anterior segment shell model, preparing a plurality of the fundus shells according to the fundus shell model, and preparing a plurality of the color block carrier plates according to the color block carrier plate model; Step S4, dye preparation stage, first, using the pigment raw materials to prepare a plurality of primary color dyes; then, according to a preset color formula, using the plurality of primary color dyes to mix and produce a plurality of complex color dyes; finally, using the spectrum measurement device to measure the actual white light reflection spectrum and fluorescence emission spectrum information of each dye; Step S5, a color block forming stage, wherein the multiple dyes prepared in step S4 are colored in each of the dye pools one by one, thereby obtaining multiple color block groups; Step S6, component integration stage, firstly, the plurality of color block carrier plates with the color block groups are respectively attached to the inner surfaces of the plurality of fundus shells at positions within the fundus field of view, and then the plurality of fundus shells with the color block carrier plates and the front segment shells are integrated and installed, and inspected, so as to obtain a fundus camera color space calibration device.

7. The method for preparing the fundus camera color space calibration device according to claim 6, characterized in that: Also includes: Step S7, testing and optimization stage, connecting the fundus camera color space calibration device obtained in step S6 to the fundus camera, simulating the actual fundus imaging process to perform imaging test on each of the color blocks, and optimizing and adjusting the anterior segment shell model, the fundus shell model, and the color block carrier plate model according to the simulated imaging test results.

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