Multispectral fundus imaging device and method

Abstract

The present invention relates to a multispectral fundus imaging device and method. By setting a camera device, a peripheral image of a human eye can be captured, thereby obtaining the position of the human eye's pupil and confirming the position of the human eye. By setting a laser fixation optical path, a fixation object can be provided for the human eye, thereby alleviating detection errors caused by nystagmus. In addition, the laser fixation optical path also outputs a laser signal having two laser beams, and the laser fixation optical path is movably arranged on a movable bracket along a reference axis of the laser fixation optical path. The two output laser beams tend to overlap in the human eye due to the movement of the laser fixation optical path, and two laser line segments are displayed in the obtained image information. When the two laser line segments overlap in the image information, the fundus can be exposed through the set multispectral optical path, and finally fundus image information is obtained through the imaging optical path, thereby realizing high-power fundus multispectral imaging and fundus information acquisition.

Description

Technical Field

[0001] The present invention relates to the technical field of optical systems, and in particular to a multispectral fundus imaging device and method. Background Art

[0002] Fundus imaging is crucial for screening for fundus diseases. Currently, fundus examination equipment is primarily divided into two categories: scanning imaging devices and flood imaging devices. Scanning imaging devices typically use a laser light source and rely on internal scanning mechanisms to image the fundus. This imaging method inevitably results in complex equipment structure and high cost. Flood imaging devices primarily include color fundus imaging devices and multispectral fundus cameras.

[0003] Fundus color imaging equipment uses white light to illuminate the fundus, providing high-resolution color images and is widely used for routine examinations of fundus diseases. However, due to limitations in the light source, it cannot provide detailed information about the deep layers or subtle structures of the fundus, limiting its application in diagnosing certain diseases.

[0004] Multispectral fundus cameras use light sources in multiple wavelengths to capture fundus images. By analyzing the imaging information at different wavelengths, they can obtain more information about fundus tissue, such as details of blood vessels, the retina, and the macula. However, multispectral fundus cameras require multiple exposures over a period of time to obtain images of the fundus at different wavelengths. During fundus examinations, nystagmus can cause displacement in the multispectral fundus images obtained at different wavelengths. This displacement can affect subsequent image analysis and processing, such as image fusion and dual-band blood oxygen calculation. Summary of the Invention

[0005] The technical problem addressed by the present invention is how to overcome the technical shortcomings of existing fundus examination equipment, which include the inability to provide detailed information about the deep layers or subtle structures of the fundus, and the displacement of multispectral fundus images obtained in different wavelength bands. To overcome these technical shortcomings, the present invention provides a multispectral fundus imaging device and method, specifically comprising a multispectral fundus imaging device and a multispectral fundus imaging method.

[0006] The present invention provides a multispectral fundus imaging device, comprising a movable support and:

[0007] A photographing device, used to capture a peripheral image of a human eye to obtain a pupil position of the human eye;

[0008] a laser fixation optical path, movably arranged on the movable bracket along a reference axis of the laser fixation optical path, for providing a fixation object for the human eye and outputting a laser signal having two laser beams;

[0009] A multi-spectral optical path, used for outputting a multi-spectral signal having multiple signals of different wavelength bands;

[0010] a trunk optical path, for introducing the laser signal into the human eye so as to be reflected by the fundus of the human eye to form a first reflection signal corresponding to the laser signal, and introducing the multispectral signal into the human eye so as to be reflected by the fundus of the human eye to form a second reflection signal corresponding to the multispectral signal;

[0011] an imaging optical path, for collecting image information of the first reflection signal and the second reflection signal;

[0012] Among them, the laser fixation optical path and the main optical path are arranged in sequence along the propagation direction of the laser signal, the multispectral optical path and the main optical path are arranged in sequence along the propagation direction of the multispectral signal, and the main optical path and the imaging optical path are arranged in sequence along the propagation direction of the first reflected signal.

[0013] The multispectral fundus imaging device disclosed in the present invention can capture the peripheral image of the human eye by setting a photographing device, and then obtain the pupil position of the human eye to confirm the position of the human eye; by setting a laser fixation optical path, it can provide a fixation object for the human eye, thereby alleviating the detection error caused by nystagmus, and the set laser fixation optical path can also output a laser signal with two laser beams, and the laser fixation optical path is movably set along the reference axis of the laser fixation optical path on a movable bracket, so that the two output laser beams will tend to overlap in the human eye due to the movement of the laser fixation optical path. This process can be collected by the set imaging optical path, and the change of the two laser line segments will be displayed in the obtained image information. When the two laser line segments in the image information overlap, the fundus can be exposed through the set multispectral optical path, and finally the fundus image information is obtained through the imaging optical path, realizing high-efficiency fundus multispectral imaging and fundus information collection. Therefore, the multispectral fundus imaging device of the present invention does not need to consider the impact of too many light source types or too large a volume on illumination. It simplifies beam shaping and utilizes the human eye's ability to adjust, improving fundus imaging quality. Furthermore, it eliminates the need for a separate fixation light source optical path, thereby improving the overall illumination efficiency of the device and reducing the displacement of multispectral fundus images.

[0014] In one possible embodiment, the photographing device includes a first photographing device and a second photographing device distributed on both sides of the main optical path, the first photographing device includes a first near-infrared lighting source and a first near-infrared camera, and the second photographing device includes a second near-infrared lighting source and a second near-infrared camera; then, the two near-infrared cameras can be used to photograph the human eye and its surroundings, while relying on the reflected light of the first near-infrared lighting source and the second near-infrared lighting source to locate the position of the human eye pupil, so as to improve the efficiency of subsequent information collection.

[0015] In one possible embodiment, the laser fixation optical path includes a laser light source, a collimating lens group, a double wedge prism, a rectangular slit and a fixation light source, wherein the laser light source is used to generate a laser beam, and the laser light source, the collimating lens group, the double wedge prism and the rectangular slit are arranged in sequence along the propagation direction of the laser beam, and the double wedge prism is used to modulate the laser beam into a laser signal having two laser beams. The fixation light source is located outside the propagation path of the laser signal and is located within the receivable light area of ​​the main optical path; the laser signal emitted by the laser light source will be collimated by the collimating lens group and then processed by the double wedge prism to form a laser signal having two laser beams, which can be emitted through the rectangular slit. Since the fixation light source is located outside the propagation path of the laser signal, the interference of different light beams in fundus imaging can be reduced, thereby enabling the human eye to recognize the fixation object.

[0016] In one possible embodiment, the main optical path includes a beam splitter, a first illumination mirror group, a hollow reflector, and a retina objective lens connected to the human eye, which are sequentially arranged along the propagation direction of the laser signal. The beam splitter is used to reflect the laser signal to the first illumination mirror group and transmit the multispectral signal to the first illumination mirror group.

[0017] The hollow reflector is configured to reflect the laser signal and / or the multispectral signal processed by the first illumination mirror group to the retina objective lens, and transmit the first reflected signal and / or the second reflected signal processed by the retina objective lens to the imaging optical path;

[0018] The laser signal emitted from the rectangular slit can be reflected by the beam splitter to the first illumination mirror group, to be collimated or focused by the first illumination mirror group, and then reflected by the hollow reflector to the retina objective lens, and finally focused to the fundus by the retina objective lens; and the multispectral signal output by the multispectral optical path can be transmitted by the beam splitter to the first illumination mirror group, to be collimated or focused by the first illumination mirror group, and then reflected by the hollow reflector to the retina objective lens, and finally focused to the fundus by the retina objective lens; not only that, the reflected signal (first reflected signal or second reflected signal) formed by the fundus will be focused or collimated by the retina objective lens, and then transmitted by the hollow reflector to the imaging optical path.

[0019] In a possible embodiment, the imaging optical path includes a secondary imaging mirror group, a tertiary imaging mirror group and a detector arranged in sequence along the propagation direction of the first reflected signal, the retina objective lens, the hollow reflector and the secondary imaging mirror group are arranged in sequence along the propagation direction of the first reflected signal, and the secondary imaging mirror group is movably arranged on the movable bracket along the optical axis of the secondary imaging mirror group; the first reflected signal or the second reflected signal is focused in sequence by the secondary imaging mirror group and the tertiary imaging mirror group, and finally received by the detector to form image information. Since the secondary imaging mirror group is movable, not only can the image quality of the image information obtained by the detector be adjusted, but also, in cooperation with the laser fixation optical path, the clarity of the two laser line segments displayed in the image information obtained by the detector can be improved.

[0020] In one possible embodiment, the imaging device further includes an imaging objective lens and a linkage mechanism disposed on the movable bracket, wherein the rectangular slit, the imaging objective lens, and the beam splitter are sequentially disposed along the propagation direction of the laser signal, and the linkage mechanism is used to carry the secondary imaging lens group, the laser light source, the collimating lens group, the double wedge prism, the rectangular slit, and the fixation light source and to synchronously move the secondary imaging lens group, the laser light source, the collimating lens group, the double wedge prism, the rectangular slit, and the fixation light source; by arranging the imaging objective lens, the aberration of the laser emitted from the rectangular slit can be compensated, so that the laser signal is reflected by the beam splitter, refracted by the first illumination lens group, and reflected by the hollow reflector, and finally the laser signal emitted from the rectangular slit is imaged on the fundus; the synchronous movement performed by the linkage mechanism can ensure that when the two laser beams separated after passing through the rectangular slit are aligned on the retina of the fundus, the displacement of the secondary imaging lens group just compensates for the refractive error of the human eye, and therefore, the refractive power information of the human eye can be further obtained according to the movement of the linkage mechanism.

[0021] In one possible embodiment, the multispectral optical path includes a first multispectral light source module, a first coupling objective lens group, a first illumination optical fiber, a second illumination lens group, a plane reflector, a third illumination lens group, and a black spot plate, which are sequentially arranged along the propagation direction of the multispectral signal. The first multispectral light source module is used to generate the multispectral signal.

[0022] The first illumination optical fiber is an optical fiber bundle consisting of multiple optical fibers, and the shape of one end close to the second illumination mirror group is annular;

[0023] The black spot plate is a glass plate with an opaque object in the center area;

[0024] The use of the above-mentioned first illumination optical fiber can reduce the size of the light source, reduce the size of the subsequent illumination beam, and reduce the cost. At the same time, the illumination optical fiber at the annular output port can obtain an annular light spot without losing illumination energy, and the cost is low. Furthermore, the combination of the second illumination mirror group, the plane reflector, the third illumination mirror group, the black dot plate, the beam splitter, and the first illumination mirror group can image the annular light spot output by the first illumination optical fiber on the reflector area of ​​the hollow reflector, and then, after reflection by the hollow reflector, it is focused by the retinal objective lens to the pupil of the human eye to form an annular light spot at the pupil, which illuminates the fundus area after propagating through the inside of the human eye.

[0025] In one possible embodiment, the multispectral optical path further includes a second multispectral light source module and a dichroic mirror, wherein the second multispectral light source module is used to generate the multispectral signal, but the center wavelength of all wavelength bands of the generated multispectral signal is smaller than the center wavelength of the dichroic mirror, while the center wavelength of all wavelength bands of the multispectral signal generated by the first multispectral light source module is larger than the center wavelength of the dichroic mirror;

[0026] The dichroic mirror is configured to transmit the multispectral signal generated by the first multispectral light source module to the first coupling objective lens group, and reflect the multispectral signal generated by the second multispectral light source module to the first coupling objective lens group;

[0027] The dichroic mirror has a high reflectivity for light of a specific wavelength and can reflect most of the incident light shorter than its central wavelength; it has a high transmittance for light longer than its central wavelength, allowing the light to pass smoothly and reducing energy loss. In addition, when a second multispectral light source module is added, the types of hyperspectral bands can be increased, thereby improving the quality of imaging information.

[0028] In one possible embodiment, the multispectral optical path further includes a second multispectral light source module, a second coupling objective lens group, a second illumination fiber, and a dichroic mirror. The second multispectral light source module is used to generate the multispectral signal, but the center wavelength of all wavelength bands of the generated multispectral signal is smaller than the center wavelength of the dichroic mirror, while the center wavelength of all wavelength bands of the multispectral signal generated by the first multispectral light source module is larger than the center wavelength of the dichroic mirror.

[0029] The second multi-spectral light source module, the second coupling objective lens assembly, the second illumination fiber, and the dichroic mirror are sequentially arranged along a propagation direction of the multi-spectral signal generated by the second multi-spectral light source module; and the first illumination fiber, the dichroic mirror, and the second illumination lens assembly are sequentially arranged along a propagation direction of the multi-spectral signal generated by the first multi-spectral light source module;

[0030] The second illumination optical fiber is an optical fiber bundle consisting of multiple optical fibers, and the shape of one end close to the dichroic mirror is annular;

[0031] The dichroic mirror is configured to transmit the multispectral signal generated by the first multispectral light source module to the second lighting mirror group, and reflect the multispectral signal generated by the second multispectral light source module to the second lighting mirror group;

[0032] The combination of the second illumination fiber and the first illumination fiber, under the adjustment of the dichroic mirror, not only increases the number of spectral bands, but also forms a brighter annular light spot at the pupil. After propagating through the human eye, it illuminates the fundus area, further improving the quality of imaging information.

[0033] Another technical solution of the present invention is to provide a multispectral fundus imaging method, comprising the following steps:

[0034] S1: Turn on the camera to obtain the pupil position of the human eye, and move the movable bracket according to the obtained pupil position so that the human eye is located in the operable area of ​​the main optical path;

[0035] S2: shutting down the photographing device, causing the multispectral optical path to output a multispectral signal of a single wavelength band, and causing the laser fixation optical path to provide a fixation object for the human eye and output a laser signal having two laser beams;

[0036] S3: moving the laser fixation optical path, acquiring image information through the imaging optical path, and stopping the laser fixation optical path from outputting when two laser line segments displayed by the acquired image information overlap;

[0037] S4: enabling the multispectral optical path to output a multispectral signal of all wavelength band signals to obtain a fundus multispectral image using the image information acquired by the imaging optical path.

[0038] The method disclosed in the present invention first captures the peripheral image of the human eye through a photographic device, and then obtains the pupil position of the human eye to confirm the position of the human eye; then, a fixation object is provided for the human eye through a laser fixation optical path, thereby alleviating the detection error caused by nystagmus, and a laser signal with two laser beams is output through the laser fixation optical path, and after the laser fixation optical path is moved to the point where the two laser line segments in the image information overlap, the fundus is exposed through a multispectral optical path, and finally the fundus image information is obtained through the imaging optical path, thereby realizing high-power fundus multispectral imaging and fundus information acquisition. Therefore, the method in the present invention does not need to consider the effects of too many types of light sources and the excessive volume of the light source on lighting, and the beam shaping is simple, and the adjustment ability of the human eye can be used to improve the quality of fundus photography. Moreover, there is no need to additionally separate the fixation light source optical path, thereby improving the lighting efficiency of the overall device and reducing the displacement of the multispectral fundus image. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a schematic diagram of the optical path structure included in a multispectral fundus imaging device disclosed in the first embodiment of the present invention;

[0040] Figure 2 Schematic diagram of the distribution of fixation light sources disclosed in the first embodiment of the present invention;

[0041] Figure 3 This is a schematic structural diagram of the first multi-spectral light source module disclosed in Example 1 of the present invention;

[0042] Figure 4 This is a flow chart of the method disclosed in Example 1 of the present invention;

[0043] Figure 5 This is a schematic diagram of the optical path structure included in a multispectral fundus imaging device disclosed in the second embodiment of the present invention;

[0044] Figure 6 Schematic diagram of the distribution of fixation light sources disclosed in the second embodiment of the present invention;

[0045] Figure 7 A multispectral fundus imaging device disclosed in the third embodiment of the present invention includes a schematic diagram of an optical path structure.

[0046] Description of reference numerals:

[0047] 1. First near-infrared illumination light source, 2. Second near-infrared illumination light source, 3. Second near-infrared camera, 4. First near-infrared camera, 5. First multi-spectral light source module, 5-1. Circuit board, 5-2. Photodiode, 6. Second multi-spectral light source module, 7. Second coupling objective lens group, 8. First coupling objective lens group, 9. First illumination fiber, 10. Second illumination fiber, 11. Dichroic mirror, 12. Second illumination lens group, 13. Plane reflector, 14. The third lighting mirror group, 15. Black dot plate, 16. Spectrometer, 17. The first lighting mirror group, 18. Hollow reflector, 19. Retina objective lens, 20. Human eye, 21. Secondary imaging mirror group, 22. Tertiary imaging mirror group, 23. Detector, 24. Laser light source, 25. Collimating lens group, 26. Double wedge prism, 27. Rectangular slit, 28. Fixation light source, 28-1. Micro display, 28-2. Fixation pattern, 29. Imaging objective lens, 30. Linkage mechanism. DETAILED DESCRIPTION

[0048] First, those skilled in the art should understand that these embodiments are merely used to explain the technical principles of the embodiments of the present application and are not intended to limit the scope of protection of the embodiments of the present application. Those skilled in the art may adjust them as needed to suit specific application scenarios.

[0049] According to usage conventions in the optical field, "optical path" has two meanings: one is the route that light travels; the other is a structure formed by a combination of optical elements that enables light to travel along a specified path. For the sake of uniform terminology, the "optical path" mentioned in this application represents the second meaning, that is, a structure formed by a combination of optical elements that enables light to travel along a specified path. In addition, the coincidence of the optical axes between the first and second optical elements mentioned means that the angle (acute angle) between the optical axis of the first optical element and the optical axis of the second optical element is no greater than 2 arc minutes, and the distance between the two is no greater than 50μm. Similarly, the coincidence of the axis of the human eye with the optical axis of an optical element means that the angle (acute angle) between the axis of the human eye and the optical axis of an optical element is no greater than 2 arc minutes, and the distance between the two is no greater than 50μm.

[0050] In the embodiments of the present application, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, a first feature being "above," "above," and "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0051] The following will use three embodiments to further illustrate the technical solution of this application in combination with the accompanying drawings and specific embodiments.

[0052] Example 1:

[0053] See also Figures 1 to 3 This embodiment discloses a multispectral fundus imaging device. Figure 1Schematic diagram of the optical path structure of the imaging device, which includes a movable bracket and a photographing device, a laser fixation optical path, a multispectral optical path, a trunk optical path, an imaging objective lens 29, a linkage mechanism 30 and an imaging optical path arranged on the movable bracket. The photographing device is used to capture a peripheral image of the human eye 20 to obtain the pupil position of the human eye 20. The laser fixation optical path is movably arranged on the movable bracket along the reference axis of the laser fixation optical path, and is used to provide a fixation object for the human eye 20 and output a laser signal having two laser beams. The multispectral optical path is used to output a multispectral signal having multiple different wavelength band signals. The trunk optical path is used to introduce the laser signal into the human eye 20 so that it is reflected by the fundus of the human eye 20 to form a first reflection signal corresponding to the laser signal, and to introduce the multispectral signal into the human eye 20 so that it is reflected by the fundus of the human eye 20 to form a second reflection signal corresponding to the multispectral signal. The imaging optical path is used to collect image information of the first reflection signal and the second reflection signal. Among them, the laser fixation optical path, imaging objective lens 29, and main optical path are arranged in sequence along the propagation direction of the laser signal, the multispectral optical path and main optical path are arranged in sequence along the propagation direction of the multispectral signal, and the main optical path and imaging optical path are arranged in sequence along the propagation direction of the first reflected signal.

[0054] See also Figure 1 In this embodiment, the photographic device includes a first photographic device and a second photographic device, which are located on either side of the main optical path. The first photographic device includes a first near-infrared illumination source 1 and a first near-infrared camera 4, and the second photographic device includes a second near-infrared illumination source 2 and a second near-infrared camera 3. The first near-infrared illumination source 1 and the second near-infrared illumination source 2 can be light-emitting diodes, and their center wavelengths can be determined based on actual conditions. In this embodiment, the first near-infrared illumination source 1 uses a light-emitting diode with a center wavelength of 850 nm, and the second near-infrared illumination source 2 uses a light-emitting diode with a center wavelength of 850 nm. The first near-infrared camera 4 and the second near-infrared camera 3 are both infrared detectors used to capture the human eye 20 and its surroundings. These two cameras rely on the reflected light emitted by the first near-infrared illumination source 1 and the second near-infrared illumination source 2 at the human eye 20 to locate the pupil position of the human eye 20.

[0055] Please continue to see Figure 1In this embodiment, the laser fixation optical path includes a laser light source 24, a collimating lens assembly 25, a double wedge prism 26, a rectangular slit 27, and a fixation light source 28. The laser light source 24, the collimating lens assembly 25, the double wedge prism 26, the rectangular slit 27, and the imaging objective lens 29 are arranged in sequence along the propagation direction of the laser beam, and their optical axes coincide. Thus, the reference axis of the laser fixation optical path coincides with the optical axes of the laser light source 24, the collimating lens assembly 25, the double wedge prism 26, the rectangular slit 27, and the imaging objective lens 29. The laser light source 24 is used to generate a laser beam, which can assist in zooming. The wavelength band is generally the near-infrared band, such as 780nm, but other wavelength bands can also be selected as needed. The collimating lens assembly 25 is an optical assembly composed of one or more spherical or aspherical lenses. The double wedge prism 26 is a prism composed of two identical triangular pyramid-shaped transparent optical materials stacked together, and is used to modulate the laser beam into a laser signal having two laser beams. The laser signal will then enter the human eye 20 and ultimately present two laser line segments in the image information obtained by the imaging optical path. The refractive power of the human eye 20 can be determined by moving the position of the laser fixation optical path until the two laser line segments in the image information coincide.

[0056] See also Figure 2 In the field of optics, a slit usually refers to a light-blocking plate with a tiny rectangular light-through hole, which is used to cut and filter the incident light according to certain rules to adjust the light distribution pattern. Similarly, the rectangular slit 27 in this embodiment is a light-blocking plate with a tiny rectangular light-through hole. The fixation light source 28 is located outside the propagation path of the laser signal and is located in the light-receiving area of ​​the main optical path. In this embodiment, the fixation light source 28 is a light source composed of multiple light-emitting diodes, such as Figure 2 As shown, the fixation light source 28 is arranged on the light blocking plate of the rectangular slit 27 and is distributed around the tiny rectangular light hole.

[0057] Please continue to see Figure 1 In this embodiment, the main optical path includes a beam splitter 16, a first lighting mirror group 17, a hollow reflector 18, and a retina objective lens 19 connected to the human eye 20, which are arranged in sequence along the propagation direction of the laser signal. The beam splitter 16 is used to reflect the laser signal to the first lighting mirror group 17 and transmit the multi-spectral signal to the first lighting mirror group 17. The hollow reflector 18 is configured to reflect the laser signal and / or multi-spectral signal processed by the first lighting mirror group 17 to the retina objective lens 19, and transmit the first reflected signal and / or the second reflected signal processed by the retina objective lens 19 to the imaging optical path. Figure 1 In FIG, the vertical dotted line closest to the retina objective lens 19 represents the image plane of the retina objective lens 19. The first illumination lens assembly 17 is an optical system composed of one or more spherical or aspherical lenses.

[0058] Please continue to see Figure 1In this embodiment, the imaging optical path includes a secondary imaging mirror group 21, a tertiary imaging mirror group 22 and a detector 23, which are arranged in sequence along the propagation direction of the first reflected signal. The retina objective lens 19, the hollow reflector 18, and the secondary imaging mirror group 21 are arranged in sequence along the propagation direction of the first reflected signal, and the optical axes of the retina objective lens 19, the hollow reflector 18, and the secondary imaging mirror group 21 are arranged to coincide with each other. The secondary imaging mirror group 21 is movably arranged on a movable bracket along the optical axis of the secondary imaging mirror group 21. Figure 1 In FIG, the vertical dotted line on the right side of the secondary imaging lens assembly 21 is the image plane of the secondary imaging lens assembly 21.

[0059] Please continue to see Figure 1 In this embodiment, the linkage mechanism 30 is used to carry the secondary imaging lens group 21, the laser light source 24, the collimating lens group 25, the double wedge prism 26, the rectangular slit 27 and the fixation light source 28 and to synchronously move the secondary imaging lens group 21, the laser light source 24, the collimating lens group 25, the double wedge prism 26, the rectangular slit 27 and the fixation light source 28.

[0060] See also Figure 1 and Figure 3 In this embodiment, the multispectral optical path includes a first multispectral light source module 5, a first coupling objective lens group 8, a first illumination fiber 9, a second illumination lens group 12, a plane reflector 13, a third illumination lens group 14, and a black dot plate 15, which are sequentially arranged along the propagation direction of the multispectral signal. The first multispectral light source module 5 is used to generate a multispectral signal. The first multispectral light source module 5 is composed of a circuit board 5-1 and a plurality of photodiodes 5-2 of different spectral bands arranged on the circuit board 5-1. The structural diagram thereof is shown in FIG. Figure 3 As shown, the central wavelengths of the spectral bands of this embodiment include 660nm, 740nm, 780nm, and 850nm. The first coupling objective lens group 8 is an optical system composed of one or more spherical or aspherical lenses. The lens material can be glass or plastic, and the overall optical focal length is positive. The first illumination fiber 9 is an optical fiber bundle composed of multiple optical fibers, and the shape of the end near the second illumination lens group 12 is annular, while the shape of the end near the first coupling objective lens group 8 can be circular or square. The black dot plate 15 is a glass plate with an opaque object in the center area. The second illumination lens group 12 and the third illumination lens group 14 are both optical systems composed of one or more spherical or aspherical lenses.

[0061] See also Figure 4 The following further discloses a method for using the multispectral fundus imaging device according to this embodiment, which includes the following steps:

[0062] S1: The pupil position of the human eye 20 is obtained by a photographing device, and the movable bracket is moved according to the obtained pupil position so that the human eye 20 is located in the operable area of ​​the main optical path.

[0063] Specifically, the first near-infrared illumination light source 1, the second near-infrared illumination light source 2, the first near-infrared camera 4 and the second near-infrared camera 3 are turned on, the pupil position of the human eye 20 is obtained according to the images obtained by the first near-infrared camera 4 and the second near-infrared camera 3, and the movable bracket is moved according to the obtained pupil position so that the eye axis of the human eye 20 coincides with the optical axis of the retina objective lens 19 of the main optical path.

[0064] S2: The multispectral optical path is made to output a multispectral signal of a wavelength band signal, and the laser fixation optical path is made to provide a fixation object for the human eye 20 and output a laser signal having two laser beams.

[0065] Specifically, after executing step S1, the first near-infrared illumination light source 1, the second near-infrared illumination light source 2, the first near-infrared camera 4 and the second near-infrared camera 3 are turned off, and the 850nm near-infrared light source, the laser light source 24 and the fixation light source 28 on the first multi-spectral light source module 5 are turned on.

[0066] S3: moving the laser fixation optical path, acquiring image information through the imaging optical path, and stopping the output of the laser fixation optical path when two laser line segments displayed by the acquired image information overlap, and simultaneously stopping the movement of the laser fixation optical path.

[0067] Specifically, when the two laser line segments displayed by the acquired image information overlap, the laser light source 24 and the fixation light source 28 are turned off.

[0068] S4: The multispectral optical path is made to output multispectral signals of all wavelength band signals to obtain a multispectral fundus image using the image information acquired by the imaging optical path.

[0069] Specifically, the multispectral light sources of 850 nm, 780 nm, 740 nm, and 660 nm of the first multispectral light source module 5 are sequentially exposed, and a multispectral image of the fundus is obtained through the detector 23 .

[0070] The multispectral fundus imaging device disclosed in this embodiment can capture a peripheral image of the human eye 20 by providing a camera, thereby obtaining the pupil position of the human eye 20 and confirming the position of the human eye 20. By providing a laser fixation optical path, a fixation target can be provided for the human eye 20, thereby alleviating detection errors caused by nystagmus. Furthermore, the laser fixation optical path can output a laser signal having two laser beams. The laser fixation optical path is movably arranged on a movable bracket along a reference axis of the laser fixation optical path. Therefore, the two output laser beams tend to overlap in the human eye 20. This process can be captured by the imaging optical path, and two laser line segments will appear in the obtained image information. When the two laser line segments in the image information overlap, the fundus can be exposed through the multispectral optical path, and ultimately fundus image information can be obtained through the imaging optical path, achieving high-power multispectral fundus imaging and fundus information acquisition. Therefore, the multispectral fundus imaging device of this embodiment does not need to consider the impact of too many light source types or too large a light source on illumination. The beam shaping is simple, and the adjustment ability of the human eye 20 can be utilized to improve the quality of fundus imaging. Furthermore, there is no need to separate the fixation light source optical path, thereby improving the overall lighting efficiency of the device and reducing the displacement of the multispectral fundus image.

[0071] Example 2:

[0072] See also Figure 5 This embodiment further discloses a multispectral fundus imaging device. Figure 5 This is a schematic diagram of the optical path structure of the imaging device. This imaging device differs from Example 1 in that the multispectral optical path of the imaging device includes a first multispectral light source module 5, a second multispectral light source module 6, a first coupling objective lens assembly 8, a first illumination fiber 9, a dichroic mirror 11, a second illumination lens assembly 12, a plane reflector 13, a third illumination lens assembly 14, and a blackspot plate 15. Both the first multispectral light source module 5 and the second multispectral light source module 6 are used to generate multispectral signals. However, the center wavelengths of all wavelength bands of the multispectral signal generated by the second multispectral light source module 6 are smaller than the center wavelength of the dichroic mirror 11, while the center wavelengths of all wavelength bands of the multispectral signal generated by the first multispectral light source module 5 are larger than the center wavelength of the dichroic mirror 11. The structures of the first coupling objective lens assembly 8, the first illumination fiber 9, the second illumination lens assembly 12, the plane reflector 13, the third illumination lens assembly 14, and the blackspot plate 15 are the same as those of Example 1.

[0073] In this embodiment, the dichroic mirror 11 is configured to transmit the multispectral signal generated by the first multispectral light source module 5 to the first coupling objective lens assembly 8, and to reflect the multispectral signal generated by the second multispectral light source module 6 back to the first coupling objective lens assembly 8. The first coupling objective lens assembly 8, the first illumination fiber 9, the second illumination lens assembly 12, the plane reflector 13, the third illumination lens assembly 14, and the black spot plate 15 are arranged in sequence along the propagation direction of the multispectral signal output by the dichroic mirror 11.

[0074] In this embodiment, the center wavelength of the dichroic mirror 11 is 650 nm. The center wavelengths of the spectral bands of the first multi-spectral light source module 5 are all greater than 650 nm, including 660 nm, 740 nm, 780 nm, and 850 nm. The center wavelengths of the spectral bands of the second multi-spectral light source module 6 are all less than 650 nm, including 630 nm, 600 nm, 550 nm, and 470 nm.

[0075] In addition, see Figure 6 In this embodiment, the fixation light source 28 is still placed on the light blocking plate of the rectangular slit 27, but the fixation light source 28 in this embodiment is composed of a plurality of micro displays 28-1, such as Figure 6 As shown, a fixed pattern 28-2 is displayed on one of the micro displays 28-1.

[0076] This embodiment overcomes the technical drawbacks of prior art multispectral fundus cameras, such as the difficulty in balancing the number of multispectral light sources, light source power, and cost, by providing a first multispectral light source module 5, a second multispectral light source module 6, a first coupling objective lens assembly 8, a first illumination fiber 9, a dichroic mirror 11, a second illumination lens assembly 12, a plane reflector 13, a third illumination lens assembly 14, and a black dot plate 15. By coupling the illumination light sources of the two spectral light source modules through two coupling lens assemblies, there are no excessive restrictions on the size and number of multispectral light sources, greatly increasing the flexibility of light source selection. The multispectral signal output by the dichroic mirror 11 enters the first illumination fiber 9 after being coupled by the first coupling objective lens assembly 8. The multispectral signal is reflected multiple times within the first illumination fiber 9, thereby homogenizing the light spot. In particular, the use of an illumination fiber with a ring-shaped output port facilitates beam shaping, reduces the difficulty of beam shaping, easily modifies the illumination wavelength band, and expands the functionality of the multispectral fundus camera. The rectangular slit 27 is conjugate with the retina of the human eye 20. Therefore, placing the fixation light source 28 at the rectangular slit 27 can fully utilize the adjustment function of the human eye 20 to improve the shooting effect. At the same time, it avoids adding a spectroscopic device in the imaging light path, thereby increasing the efficiency of light source utilization.

[0077] Example 3:

[0078] See also Figure 7 This embodiment further discloses a multispectral fundus imaging device. Figure 7 This is a schematic diagram of the optical path structure of the imaging device. This imaging device differs from Example 1 in that the multispectral optical path of the imaging device includes a first multispectral light source module 5, a second multispectral light source module 6, a second coupling objective lens assembly 7, a first coupling objective lens assembly 8, a first illumination fiber 9, a dichroic mirror 11, a second illumination lens assembly 12, a plane reflector 13, a third illumination lens assembly 14, and a blackspot plate 15. Both the first multispectral light source module 5 and the second multispectral light source module 6 are used to generate multispectral signals. However, the center wavelengths of all wavelength bands of the multispectral signal generated by the second multispectral light source module 6 are smaller than the center wavelength of the dichroic mirror 11, while the center wavelengths of all wavelength bands of the multispectral signal generated by the first multispectral light source module 5 are larger than the center wavelength of the dichroic mirror 11. The structures of the first coupling objective lens assembly 8, the first illumination fiber 9, the second illumination lens assembly 12, the plane reflector 13, the third illumination lens assembly 14, and the blackspot plate 15 are the same as those of Example 1.

[0079] Please continue to see Figure 7 In this embodiment, the second multispectral light source module 6, the second coupling objective lens assembly 7, the second illumination fiber 10, and the dichroic mirror 11 are sequentially arranged along the propagation direction of the multispectral signal generated by the second multispectral light source module 6. The first illumination fiber 9, the dichroic mirror 11, and the second illumination lens assembly 12 are sequentially arranged along the propagation direction of the multispectral signal generated by the first multispectral light source module 5. The second illumination fiber 10 is a fiber bundle consisting of multiple optical fibers. The end near the dichroic mirror 11 is annular in shape, and the end near the second coupling objective lens assembly 7 is circular or square in shape. The dichroic mirror 11 is configured to transmit the multispectral signal generated by the first multispectral light source module 5 to the second illumination lens assembly 12 and reflect the multispectral signal generated by the second multispectral light source module 6 back to the second illumination lens assembly 12.

[0080] In this embodiment, the center wavelength of the dichroic mirror 11 is 650 nm. The center wavelengths of the spectral bands of the first multi-spectral light source module 5 are all greater than 650 nm, including 660 nm, 740 nm, 780 nm, and 850 nm. The center wavelengths of the spectral bands of the second multi-spectral light source module 6 are all less than 650 nm, including 630 nm, 600 nm, 550 nm, and 470 nm.

[0081] This embodiment overcomes the technical drawbacks of prior art multispectral fundus cameras, which struggle to balance the number of multispectral light sources, light source power, and cost, by providing a first multispectral light source module 5, a second multispectral light source module 6, a second coupling objective lens assembly 7, a first coupling objective lens assembly 8, a first illumination fiber 9, a second illumination fiber 10, a dichroic mirror 11, a second illumination lens assembly 12, a plane reflector 13, a third illumination lens assembly 14, and a black dot plate 15. Coupling the illumination light sources of the two spectral light source modules through two coupling lens assemblies eliminates significant restrictions on the size and number of multispectral light sources, greatly increasing the flexibility of light source selection. The multispectral signal output by the dichroic mirror 11 enters the first illumination fiber 9 after coupling through the first coupling objective lens assembly 8. Multiple reflections within the first illumination fiber 9 and the second illumination fiber 10 homogenize the light spot. In particular, the use of ring-shaped output ports in both the first illumination fiber 9 and the second illumination fiber 10 facilitates beam shaping, reduces the difficulty of beam shaping, and makes it easier to modify the illumination wavelength band, thus expanding the functionality of the multispectral fundus camera.

[0082] In the description of the embodiments of the present application, it should be noted that in the description of the present application, terms such as "inside" and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and does not indicate or imply that the device or component must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present application.

[0083] In the description of the present application, the description with reference to the terms "one embodiment", "some embodiments", "in the present embodiment", "specific example", or "some examples" means that the specific features, mechanisms, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, mechanisms, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples, unless they are contradictory.

[0084] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A multispectral fundus imaging device, comprising a movable bracket, characterized in that: The imaging device further includes: A photographing device for capturing a peripheral image of a human eye (20) to obtain a pupil position of the human eye (20); A laser fixation optical path is movably arranged on the movable bracket along a reference axis of the laser fixation optical path, and is used to provide a fixation object for the human eye (20) and output a laser signal having two laser beams; A multi-spectral optical path, used for outputting a multi-spectral signal having multiple signals of different wavelength bands; A trunk optical path for introducing the laser signal into the human eye (20) so as to be reflected by the fundus of the human eye (20) to form a first reflection signal corresponding to the laser signal, and for introducing the multispectral signal into the human eye (20) so as to be reflected by the fundus of the human eye (20) to form a second reflection signal corresponding to the multispectral signal; an imaging optical path, for collecting image information of the first reflection signal and the second reflection signal; The laser fixation optical path and the trunk optical path are sequentially arranged along the propagation direction of the laser signal, the multispectral optical path and the trunk optical path are sequentially arranged along the propagation direction of the multispectral signal, and the trunk optical path and the imaging optical path are sequentially arranged along the propagation direction of the first reflected signal. The laser fixation optical path comprises a laser light source (24), a collimating lens group (25), a double wedge prism (26), a rectangular slit (27) and a fixation light source (28), wherein the laser light source (24) is used to generate a laser beam, and the laser light source (24), the collimating lens group (25), the double wedge prism (26) and the rectangular slit (27) are arranged in sequence along the propagation direction of the laser beam, and the double wedge prism (26) is a prism composed of two identical triangular pyramid-shaped transparent optical materials stacked together, and is used to modulate the laser beam into a laser signal having two laser beams, and the fixation light source (28) is located outside the propagation path of the laser signal and is located in the light receiving area of ​​the main optical path.

2. The multispectral fundus imaging device according to claim 1, characterized in that: The photographing device comprises a first photographing device and a second photographing device distributed on both sides of the main optical path, the first photographing device comprising a first near-infrared illumination light source (1) and a first near-infrared camera (4), and the second photographing device comprising a second near-infrared illumination light source (2) and a second near-infrared camera (3).

3. The multispectral fundus imaging device according to claim 2, characterized in that: The main optical path includes a beam splitter (16), a first lighting mirror group (17), a hollow reflector (18), and a retina objective lens (19) connected to the human eye (20) and arranged in sequence along the propagation direction of the laser signal. The beam splitter (16) is used to reflect the laser signal to the first lighting mirror group (17) and transmit the multi-spectral signal to the first lighting mirror group (17); The hollow reflector (18) is configured to reflect the laser signal and / or the multispectral signal processed by the first illumination mirror group (17) to the retina objective lens (19), and transmit the first reflected signal and / or the second reflected signal processed by the retina objective lens (19) to the imaging optical path.

4. The multispectral fundus imaging device according to claim 3, characterized in that: The imaging optical path includes a secondary imaging mirror group (21), a tertiary imaging mirror group (22), and a detector (23) which are sequentially arranged along the propagation direction of the first reflected signal; the retina objective lens (19), the hollow reflector (18), and the secondary imaging mirror group (21) are sequentially arranged along the propagation direction of the first reflected signal; and the secondary imaging mirror group (21) is movably arranged on the movable bracket along the optical axis of the secondary imaging mirror group (21).

5. The multispectral fundus imaging device according to claim 4, characterized in that: The imaging device further comprises an imaging objective lens (29) and a linkage mechanism (30) arranged on the movable bracket, wherein the rectangular slit (27), the imaging objective lens (29), and the beam splitter (16) are arranged in sequence along the propagation direction of the laser signal, and the linkage mechanism (30) is used to carry the secondary imaging lens group (21), the laser light source (24), the collimating lens group (25), the double wedge prism (26), the rectangular slit (27), and the fixation light source (28), and to synchronously move the secondary imaging lens group (21), the laser light source (24), the collimating lens group (25), the double wedge prism (26), the rectangular slit (27), and the fixation light source (28).

6. The multispectral fundus imaging device according to claim 5, characterized in that: The multi-spectral optical path comprises a first multi-spectral light source module (5), a first coupling objective lens group (8), a first illumination optical fiber (9), a second illumination lens group (12), a plane reflector (13), a third illumination lens group (14) and a black dot plate (15) which are sequentially arranged along the propagation direction of the multi-spectral signal, wherein the first multi-spectral light source module (5) is used to generate the multi-spectral signal; The first illumination optical fiber (9) is an optical fiber bundle composed of multiple optical fibers, and the shape of one end close to the second illumination mirror group (12) is annular; The black spot plate (15) is a glass plate with an opaque object provided in the central area.

7. The multispectral fundus imaging device according to claim 6, characterized in that: The multi-spectral optical path further comprises a second multi-spectral light source module (6) and a dichroic mirror (11), wherein the second multi-spectral light source module (6) is used to generate the multi-spectral signal, but the center wavelengths of all wavebands of the generated multi-spectral signal are smaller than the center wavelength of the dichroic mirror (11), while the center wavelengths of all wavebands of the multi-spectral signal generated by the first multi-spectral light source module (5) are larger than the center wavelength of the dichroic mirror (11); The dichroic mirror (11) is configured to transmit the multispectral signal generated by the first multispectral light source module (5) to the first coupling objective lens group (8), and to reflect the multispectral signal generated by the second multispectral light source module (6) to the first coupling objective lens group (8).

8. The multispectral fundus imaging device according to claim 6, characterized in that: The multi-spectral optical path further comprises a second multi-spectral light source module (6), a second coupling objective lens group (7), a second illumination optical fiber (10) and a dichroic mirror (11), wherein the second multi-spectral light source module (6) is used to generate the multi-spectral signal, but the center wavelengths of all the wavebands of the generated multi-spectral signal are smaller than the center wavelength of the dichroic mirror (11), while the center wavelengths of all the wavebands of the multi-spectral signal generated by the first multi-spectral light source module (5) are larger than the center wavelength of the dichroic mirror (11); The second multi-spectral light source module (6), the second coupling objective lens group (7), the second illumination optical fiber (10), and the dichroic mirror (11) are sequentially arranged along the propagation direction of the multi-spectral signal generated by the second multi-spectral light source module (6); and the first illumination optical fiber (9), the dichroic mirror (11), and the second illumination lens group (12) are sequentially arranged along the propagation direction of the multi-spectral signal generated by the first multi-spectral light source module (5); The second illumination optical fiber (10) is an optical fiber bundle composed of multiple optical fibers, and the shape of one end close to the dichroic mirror (11) is annular; The dichroic mirror (11) is configured to transmit the multispectral signal generated by the first multispectral light source module (5) to the second lighting mirror group (12), and to reflect the multispectral signal generated by the second multispectral light source module (6) to the second lighting mirror group (12).

9. A multispectral fundus imaging method, characterized in that: The multispectral fundus imaging device according to any one of claims 1 to 8 comprises the following steps: S1: obtaining the pupil position of the human eye (20) by a photographing device, and moving the movable bracket according to the obtained pupil position so that the human eye (20) is located in the operable area of ​​the main optical path; S2: causing the multispectral optical path to output a multispectral signal of a wavelength band signal, and at the same time causing the laser fixation optical path to provide a fixation object for the human eye (20) and output a laser signal having two laser beams; S3: moving the laser fixation optical path, acquiring image information through the imaging optical path, and stopping the laser fixation optical path from outputting when two laser line segments displayed by the acquired image information overlap; S4: enabling the multispectral optical path to output a multispectral signal of all wavelength band signals to obtain a fundus multispectral image using the image information acquired by the imaging optical path.

Images