Wide-area slit-lamp microscope based on deflection liquid lens and control method thereof

Abstract

The invention discloses a wide-area slit-lamp microscope based on a deflection liquid lens and a control method of the wide-area slit-lamp microscope, and belongs to the technical field of ophthalmic medical equipment. The system comprises a deflection zooming module and an intelligent lighting module, view field deflection and zooming are achieved through an electric control liquid lens, a slit light source is controlled in combination with synchronous servo, and the control method comprises wide area scanning, dynamic zooming deflection, intelligent lighting optimization and data archiving. The method is suitable for wide-area examination of the microscopic structure of the eye, and is especially beneficial to examination of peripheral retina conditions. The wide-area slit-lamp microscope disclosed by the invention can break through the limitation of small view field of a traditional slit lamp, and can effectively overcome the invasive operation risk faced by means of a contact type lens in order to enlarge the view field. According to the invention, the examination range can be expanded in a non-contact, non-invasive, efficient, clear and visual manner in the whole examination process, great advantages are provided in the aspect of comprehensive observation of eye tissues, the acquisition of a more comprehensive microscopic structure of eyes is facilitated, and faster and more accurate diagnosis of eye diseases is facilitated.

Description

Technical Field

[0001] This invention relates to a slit-lamp microscope, belonging to the field of ophthalmic medical equipment technology. Specifically, it relates to a wide-area slit-lamp microscope integrating a one-dimensional field-of-view deflection liquid lens and its control method, which is used to achieve mechanical-free scanning panoramic observation and high-precision diagnosis of ocular structures. Background Technology

[0002] Slit-lamp microscopy is an essential core examination tool for diagnosing ophthalmic diseases. Through the combination of a slit light source and a microscope, it primarily enables microscopic observation and optical tomography of the anterior segment (such as the cornea, anterior chamber, iris, and lens). However, due to limitations in pupil size, the examination range of tissues behind the pupil, such as the lens and retina, is restricted. Although traditional slit-lamp microscopy allows for non-contact examination of the fundus and retina using a front-mounted mirror, the limitation of pupil size is significant; even after pupil dilation, the peripheral retina cannot be fully examined, and the examination range remains limited. The diagnosis and treatment of some retinal diseases (such as the diagnosis, localization, and photocoagulation of retinal tears) require the use of a contact three-mirror to achieve a wide-area examination and treatment of the entire fundus. Glioma examination also requires a contact gonioscope under a slit-lamp microscope. Examinations using three-mirror mirrors and gonioscopes not only demand high levels of skill from the examiner and are difficult, but also have low patient acceptance. Both types of examinations require topical anesthesia, with the lens placed directly on the surface of the eyeball. Through mirror reflections at different angles, the lens is rotated at least 1-3 times within a 360° range to complete the examination of the entire retina. Finally, the ophthalmologist must mentally reconstruct the complete retinal image, a process prone to forgetting or confusion, affecting the accuracy of the results. Therefore, while traditional slit-lamp microscopy for gonioscopy or three-mirror examinations can broaden the examination range, it requires invasive procedures under topical anesthesia, which can cause patient anxiety, poor tolerance and compliance, and may also damage ocular surface tissues, leading to infection and potential medical disputes. Currently, non-contact, intelligent, wide-area imaging slit-lamp microscopy equipment is lacking. Summary of the Invention

[0003] This invention proposes a wide-area slit-lamp microscope system and control method based on a deflecting liquid prism.

[0004] (I) System Composition This wide-area slit lamp microscope system includes a liquid deflection focusing module, an intelligent illumination module, and a data processing module. Figure 1 ).

[0005] The liquid deflection prism consists of a liquid polarizing prism shell, a liquid-liquid surface transparent partition, a window glass, and two liquids 1 and 2 with different refractive indices. Figure 2 ).

[0006] Preferably, the liquid deflector prism has an aperture of 10-30mm, a deflection angle of ±50°, and can cover 110° of the retina in a single application.

[0007] Preferably, the liquid deflection prism is filled with an ionic liquid ([EMIM][BF4], refractive index 1.42) and a fluorinated silicone oil (refractive index 1.30) with a density difference of <0.01 g / cm³.

[0008] Preferably, the adjustable slit light source (width 0.1-5mm) and the liquid lens deflection are synchronously servo controlled to maintain the coaxiality of illumination and observation (deviation angle <0.5°).

[0009] Preferably, the liquid deflection prism is driven by electrowetting, dielectric force, stepper motor, electromagnetic force, or other methods.

[0010] Preferably, the default setting for the system lighting parameters is a width of 2mm and an angle of 0°.

[0011] Preferably, the system uses a low magnification of 5× for wide-area scanning.

[0012] Preferably, the system uses wide-area scanning to generate a 110° panoramic fundus image.

[0013] Preferably, the system adjusts the voltage to 60V (corresponding to a deflection of +30°) when lesion localization is achieved, and switches to 40× magnification, with a field error of <1°.

[0014] Preferably, the peripheral resolution of the imaging is 8μm, and the contrast of the lesion is optimized (improved by ≥40%).

[0015] (II) System Working Principle The liquid deflecting prism is placed in front of the objective lens of the slit-lamp microscope. By default, the deflection angle is 0°. At this time, the light incident on the slit-lamp microscope is not deflected, and the field of view is consistent with that observed directly with the slit-lamp microscope. Figure 2 When the system is working, the position of the transparent septum is precisely adjusted by voltage drive, causing controllable deformation of the interface between the two liquids. This alters the propagation direction of the incident light, deflecting the light entering the slit-lamp microscope within a range of -15° to +15°. This allows for flexible changes to the field of view of the slit-lamp microscope, enabling users to more easily observe the target object. Figure 3 This design allows for a wide range of field of view deflection without moving mechanical parts.

[0016] During clinical examination, a low-magnification wide-field scan is first performed, acquiring a large area of ​​fundus images by continuously adjusting the deflection angle; subsequently, high-magnification fine observation is conducted on the lesion area. Throughout the process, the system automatically compensates for optical aberrations caused by field-of-view deflection, ensuring consistent image quality from the center to the edge. Simultaneously, the illumination system and deflection module are synchronized in real time, ensuring optimal illumination conditions at any deflection angle. The system can automatically adjust the slit light parameters according to different examination needs, providing the most optimized illumination scheme for the observation of specific ocular tissues.

[0017] (III) Detection methods Figure 4 ) Step S1: Initialize and start the system, calibrate the zero point of the liquid lens deflection, and set the illumination parameters to the default mode; Step S2: Wide-area scanning: Low-magnification wide-area scanning to generate a panoramic mosaic of the fundus; Step S3: Lesion localization: Select the target area, adjust the voltage, and switch to high magnification; Step S4: Imaging optimization: Adjust the slit light parameters (width / angle) synchronously according to the lesion reflection characteristics. Step S5: Data Archiving: Associate the image with parameters (such as voltage value, deflection angle) and store them in PACS, supporting the DICOM standard. Attached Figure Description

[0018] Figure 1 A wide-area slit-lamp microscope system based on a deflecting liquid lens; Figure 2 Schematic diagram of a liquid deflection prism (deflection angle is 0° by default); Figure 3 Schematic diagram of a liquid deflection prism (deflection angle is ±15° under deflection conditions); Figure 4 System control flowchart; The figure labels in the above figures are as follows: 1. Liquid polarizing prism housing; 2. Liquid-liquid surface transparent separator; 3. Window glass; 4. Liquid 1; 5. Liquid 2 It should be understood that the above-mentioned figures are merely schematic diagrams, showing only their main structure and working principle, and are not limited thereto.

[0019] Although specific embodiments of the present invention have been described in detail with reference to the accompanying drawings, this should not be construed as limiting the scope of protection of this patent. Various modifications and variations that can be made by those skilled in the art without inventive effort within the scope described in the claims still fall within the scope of protection of this patent. Detailed Implementation

[0020] 1. System Construction ( Figure 1 ) 1) Deflection and Focusing Module: The liquid lens adopts a double-layer structure. The outer shell is made of lightweight aluminum alloy, and the inner cavity is filled with ionic liquid and fluorinated silicone oil, separated by a transparent septum (0.5mm thick). The driving method is to apply voltage to the piezoelectric actuator to control the rotation angle of the septum (±15°). The change in curvature of the liquid interface realizes zoom and deflection.

[0021] 2) Intelligent lighting module: The slit light source uses an LED array with a wavelength of 450-650nm, and the slit width (0.1-5mm) and angle (±50°) are dynamically adjusted by a digital micromirror device (DMD).

[0022] 3) Data processing module: image optimization and data storage.

[0023] 2. Control process ( Figure 4 ) S1 Initialization: Start the system, calibrate the liquid lens deflection zero point, and set the illumination parameters to the default mode (width 2mm, angle 0°).

[0024] S2 Wide Area Scan: Scans the retina at 5x magnification and generates a 110° panoramic image using image stitching algorithms (such as SIFT feature matching).

[0025] S3 Lesion Localization: Select the target area, adjust the voltage to 60V (corresponding to a deflection of +30°), and switch to 40× magnification.

[0026] S4 Imaging Optimization: Based on the lesion reflection characteristics (such as corneal edema areas), the slit width is adjusted to 0.5mm, and the angle is increased by 10° to improve the signal-to-noise ratio.

[0027] S5 Data Archiving: Associates images with parameters (such as voltage values ​​and deflection angles) and stores them in PACS, supporting the DICOM standard.

[0028] (V) Examples Clinical fundus and retinal examination applications of wide-field slit-lamp microscopy based on deflecting field-of-view liquid lenses A 62-year-old male patient presented with a suspected peripheral retinal tear. He was examined using the wide-field slit-lamp microscopy system based on a deflecting liquid lens described in this invention.

[0029] Inspection process: 1. After system initialization, the deflection zero point is automatically calibrated, and the slit width is set to 2mm and the angle to 0°. The patient is seated with their chin resting on the chin resting on the chin support, forehead resting on the forehead band, and both eyes aligned with the reference lines on the fixation frames on both sides. 2. The system performs automatic wide-area scanning at 5× magnification: the liquid lens continuously deflects (-15° to +15°) under electronic control, acquiring 12 fundus images with different deflection angles within 3 seconds, and generating a 110° panoramic retinal image through a real-time image stitching algorithm.

[0030] 3. The panoramic image shows a suspected lattice-like degeneration lesion in the superior temporal region. After the physician selects the target area, the system automatically adjusts the liquid lens voltage to 285V, achieving a field of view deflection of +28.5°, while simultaneously zooming to 40× magnification, with a field of view error of <0.8°.

[0031] 4. The intelligent lighting module synchronously adjusts the slit light width to 0.8mm and the deflection angle to +28.5°, optimizing the coaxiality of the lighting, significantly improving the contrast of the lesion, and clearly displaying the dry horseshoe-shaped pores in the degenerated area.

[0032] 5. The system automatically records deflection parameters (voltage, angle) and image data, archives them to the PACS system, and supports DICOM standard retrieval.

Claims

1. A wide-area slit-lamp microscope based on a deflecting liquid lens, characterized in that, It includes a deflection and focusing module, an intelligent lighting module, and a data processing module. The functions and parameters of each module are as follows: Deflection and focusing module: It adopts a double-layer liquid lens structure with a lightweight aluminum alloy shell. The inner cavity is separated by a 0.5mm thick liquid-liquid surface transparent septum and filled with two liquids with different refractive indices: an ionic liquid ([EMIM][BF4], refractive index 1.42) and fluorinated silicone oil (refractive index 1.30), with a density difference of <0.01g / cm³. The liquid lens has an aperture of 10-30mm and can achieve ±50° field deflection through electrowetting, dielectric force, stepper motor or electromagnetic force. It can cover 110° of the retina in a single shot and supports 5× to 40× magnification switching. The peripheral resolution of the examination image reaches 8μm. The driving method is to apply voltage to the piezoelectric actuator to control the rotation angle of the septum (±15°), and achieve zooming and deflection by changing the curvature of the liquid interface. Adjusting the voltage to 60V corresponds to a deflection of +30°. Intelligent lighting module: It uses an LED array as the slit light source with a wavelength range of 450-650nm. The slit width and angle are dynamically adjusted through a digital micromirror device (DMD), with the slit width adjustable from 0.1 to 5mm and the angle adjustable from ±50°. It maintains synchronous servo control with the deflection and focusing module. The default lighting parameters during system initialization are 2mm width and 0° angle, and the parameters can be adjusted according to the reflection characteristics of the lesion. Data processing module: It has image optimization and data storage functions. It can process low-magnification scanned images to generate panoramic images through image stitching algorithms (such as SIFT feature matching). At the same time, it associates and stores the images with parameters (voltage value, deflection angle) during the inspection process. It supports the DICOM standard and can be archived to the PACS system.

2. The wide-area slit-lamp microscope based on a deflecting liquid lens according to claim 1, characterized in that, When performing low-magnification (5×) wide-area scanning, the deflection and focusing module continuously adjusts the deflection angle to acquire multiple fundus images from different perspectives. After being stitched together by the data processing module, a 110° panoramic fundus image is generated. Furthermore, during the entire field of view deflection process, the system can automatically compensate for optical aberrations caused by the deflection, ensuring consistent imaging quality from the center to the edge.

3. The system according to claim 1, characterized in that, The intelligent lighting module and the deflection and focusing module are synchronously controlled using a real-time feedback mechanism. When the deflection and focusing module adjusts the deflection angle or magnification, the intelligent lighting module can synchronously adjust the width, angle, and brightness of the slit light source to ensure that the best lighting conditions can be provided at any deflection angle and magnification, adapting to the specific needs of ocular tissue observation.

4. A control method for a wide-area slit-lamp microscope based on a deflecting liquid lens as described in any one of claims 1-3, characterized in that, Includes the following steps: Step S1: Initialization: Start the system, automatically calibrate the zero point of the liquid lens deflection, and set the lighting parameters of the intelligent lighting module to the default mode, i.e., crack width 2mm and angle 0°; Step S2: Wide-area scanning: Control the deflection and focusing module to switch to 5× low magnification, and continuously adjust the deflection angle of the liquid lens (-15° to +15°) to acquire multiple fundus images from different perspectives. The data processing module uses an image stitching algorithm (such as SIFT feature matching) to process the acquired images and generate a 110° panoramic fundus image. Step S3: Lesion localization: After the physician selects the target area of ​​the suspected lesion in the panoramic mosaic, the system automatically adjusts the liquid lens driving voltage according to the location of the target area, adjusting it to 60V (corresponding to a deflection of +30°), and at the same time seamlessly switches the magnification of the deflection focusing module to 40×. Step S4: Imaging optimization: Based on the lesion's reflection characteristics (such as corneal edema areas), the system controls the intelligent illumination module to dynamically adjust the slit light parameters, adjusting the slit width to 0.5-0.8mm and the angle to match the liquid lens deflection angle (e.g., adjusting the slit angle to +28.5° when the deflection is +28.5°), thereby improving the lesion's signal-to-noise ratio; Step S5: Data Archiving: The data processing module automatically associates the images collected during the examination, the adjusted voltage values, the deflection angle and other parameters, and stores them in the PACS system in accordance with the DICOM standard for easy retrieval and consultation later.

5. The control method for a wide-area slit-lamp microscope based on a deflecting liquid lens according to claim 4, characterized in that, In step S2, when the deflection and focusing module continuously deflects and scans at 5× magnification, the rate of change of the deflection angle of the liquid lens matches the image acquisition rate, ensuring that the field of view of each acquired image is not overlapping or omitted, and that the panoramic image after image stitching has no obvious stitching marks and the overall resolution is uniform.

6. The control method for a wide-area slit-lamp microscope based on a deflecting liquid lens according to claim 4, characterized in that, In step S3, the system adjusts the liquid lens driving voltage by gradually increasing or decreasing it to avoid sudden voltage changes that could cause violent fluctuations at the liquid interface, thus ensuring a smooth magnification switching process and jitter-free imaging.

7. The application of the wide-area slit-lamp microscope based on a deflecting liquid lens according to claim 1, characterized in that, The system features a non-contact, wide-area imaging, and intelligent, non-mechanical scanning operation throughout the entire inspection process, posing no risk of invasive operation. It is suitable for multi-tissue examination of the eye and can be used for wide-area examination of anterior segment tissues such as the iridocorneal angle and lens. In particular, wide-area retinal scanning has the advantages of wide coverage, non-invasiveness, convenience and high efficiency in screening peripheral retinal degeneration, retinal tears and other lesions, and has good clinical application prospects.

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