Multispectral fundus imaging device and method

Abstract

According to the multispectral fundus imaging device and method, peripheral images of human eyes can be shot by arranging a photographing device, then pupil positions of the human eyes are obtained, and the positions of the human eyes are confirmed; a fixation object can be provided for human eyes by arranging the laser fixation light path, so that detection errors caused by nystagmus are relieved, the arranged laser fixation light path further outputs a laser signal with two laser beams, and the laser fixation light path is movably arranged on the movable support along the reference axis of the laser fixation light path, so that the laser fixation light path is convenient to use. The two output laser beams tend to coincide in human eyes due to movement of the laser fixation light path, two laser line segments can be displayed in obtained image information, when the two laser line segments in the image information coincide, the fundus can be exposed through the arranged multispectral light path, and finally fundus image information is obtained through the imaging light path. And high-power fundus multispectral imaging and fundus information acquisition are realized.

Description

Technical Field

[0001] The present invention relates to the technical field of optical systems, and more particularly, to a multi-spectral fundus imaging device and method. Background Art

[0002] Fundus imaging is very important for the screening of fundus diseases. Currently, fundus examination devices are mainly divided into two categories: scanning imaging devices and floodlight imaging devices. Scanning imaging devices generally use laser light sources and rely on internal scanning structures to image the fundus. This imaging method inevitably results in complex device structures and high prices. Floodlight imaging devices mainly include fundus color photography devices and multi-spectral fundus cameras.

[0003] Fundus color photography devices take pictures by illuminating the fundus with white light and can provide high-resolution color images, which are widely used in the routine examination of fundus diseases. However, due to the defects of the light source, it cannot provide detailed information on deep or fine structures of the fundus, thus limiting its application in the diagnosis of certain diseases.

[0004] Multi-spectral fundus cameras use light sources of multiple different bands to take fundus images. By analyzing the imaging information at different wavelengths, more information about fundus tissues can be obtained, such as details of regions like blood vessels, retina, and macula. However, multi-spectral fundus cameras need to perform continuous multiple exposures over a period of time to obtain fundus images of different bands. During fundus examinations, there is the phenomenon of nystagmus in the eye, resulting in displacement of the multi-spectral fundus images of different bands. The displacement of fundus images of different bands will affect subsequent image analysis and processing, such as image fusion and dual-band blood oxygen calculation. Summary of the Invention

[0005] The technical problem to be solved by the present invention is how to overcome the technical defects in existing fundus examination devices that cannot provide detailed information on deep or fine structures of the fundus and the displacement of multi-spectral fundus images of different bands obtained. To overcome the above technical defects, the present invention provides a multi-spectral fundus imaging device and method, specifically including a multi-spectral fundus imaging device and a multi-spectral fundus imaging method.

[0006] A multi-spectral fundus imaging device provided by the present invention includes a movable bracket and the following components provided on the movable bracket: A photographing device for capturing a peripheral image of the human eye to obtain the pupil position of the human eye; A laser fixation optical path movably provided on the movable bracket along the 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; A multi-spectral optical path for outputting a multi-spectral signal having multiple different band signals; The main optical path is used to introduce the laser signal into the human eye so that it is reflected by the fundus of the human eye to form a first reflection signal corresponding to the laser signal, and introduce the multispectral signal into the human eye so that it is reflected by the fundus of the human eye to form a second reflection signal corresponding to the multispectral signal; The imaging optical path is used to collect the image information of the first reflection signal and the second reflection signal; Wherein, 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 reflection signal.

[0007] The multispectral fundus imaging device disclosed in the present invention can capture the peripheral image of the human eye through the set photographing device, and then obtain the pupil position of the human eye to realize the confirmation of the human eye position; by setting the laser fixation optical path, a fixation object can be provided for the human eye, thereby alleviating the detection error caused by nystagmus. Moreover, the set laser fixation optical path can also output a laser signal with two laser beams, and the laser fixation optical path is movably arranged on the movable support along the reference axis of the laser fixation optical path. Therefore, the two output laser beams will tend to coincide 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 fact of the two laser line segments will be shown in the obtained image information. When the two laser line segments coincide in the image information, the fundus can be exposed through the set multispectral optical path, and finally the fundus image information can be obtained through the imaging optical path, realizing high-efficiency fundus multispectral imaging and fundus information collection. Therefore, the multispectral fundus imaging device in the present invention does not need to consider the influence of too many light source types and too large light source volume on illumination, the beam shaping is simple, the adjustment ability of the human eye can be utilized to improve the fundus photographing quality. Moreover, there is no need to separately set a fixation light source optical path, thereby improving the illumination efficiency of the overall device and reducing the displacement existing in the multispectral fundus image.

[0008] In a possible implementation manner, 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 illumination light source and a first near-infrared camera, and the second photographing device includes a second near-infrared illumination light source and a second near-infrared camera; thus, the human eye and the surrounding of the human eye can be photographed by two near-infrared cameras, and the pupil position of the human eye can be located by relying on the reflected light of the first near-infrared illumination light source and the second near-infrared illumination light source to improve the efficiency of subsequent information collection.

[0009] In a possible implementation, the laser fixation optical path includes a laser light source, a collimating lens group, a double optical wedge prism, a rectangular slit, and a fixation light source. The laser light source is used to generate a laser beam. The laser light source, the collimating lens group, the double optical wedge prism, and the rectangular slit are sequentially arranged along the propagation direction of the laser beam. The double optical wedge prism is used to modulate the laser beam into a laser signal with two laser beams. The fixation light source is located outside the propagation path of the laser signal and within the light-receiving region 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 optical wedge prism to form a laser signal with two laser beams. This laser signal can then exit through the rectangular slit. Since the fixation light source is located outside the propagation path of the laser signal, interference of different light beams in fundus imaging can be reduced, enabling the human eye to recognize the fixation object.

[0010] In a possible implementation, the main optical path includes a beam splitter, a first illumination lens group, a hollow mirror, and a retina objective lens docked with 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 onto the first illumination lens group and transmit the multi-spectral signal onto the first illumination lens group. The hollow mirror is configured to reflect the laser signal and / or the multi-spectral signal processed by the first illumination lens group onto the retina objective lens, and transmit the first reflection signal and / or the second reflection signal processed by the retina objective lens to the imaging optical path. The laser signal exiting the rectangular slit can be reflected by the beam splitter onto the first illumination lens group for collimation or focusing by the first illumination lens group, then reflected by the hollow mirror onto the retina objective lens, and finally focused by the retina objective lens onto the fundus. Moreover, the multi-spectral signal output by the multi-spectral optical path can be transmitted by the beam splitter onto the first illumination lens group, collimated or focused by the first illumination lens group, then reflected by the hollow mirror onto the retina objective lens, and finally focused by the retina objective lens onto the fundus. Not only that, the reflection signal (the first reflection signal or the second reflection signal) formed on the fundus will be focused or collimated by the retina objective lens, and then transmitted by the hollow mirror to the imaging optical path.

[0011] In a possible implementation, the imaging optical path includes a secondary imaging lens group, a tertiary imaging lens group, and a detector arranged in sequence along the propagation direction of the first reflection signal. The retina objective lens, the hollow mirror, and the secondary imaging lens group are arranged in sequence along the propagation direction of the first reflection signal. The secondary imaging lens group is movably arranged on the movable bracket along the optical axis of the secondary imaging lens group. The first reflection signal or the second reflection signal is sequentially focused by the secondary imaging lens group and the tertiary imaging lens group, and finally received and imaged by the detector to form image information. Since the secondary imaging lens group is movable, not only can the image quality of the image information obtained by the detector be adjusted, but also the clarity of the two laser line segments shown in the image information obtained by the detector can be improved in cooperation with the laser fixation optical path.

[0012] In a possible implementation, the imaging device further includes an imaging objective lens and a linkage mechanism arranged on the movable bracket. The rectangular slit, the imaging objective lens, and the beam splitter are arranged in sequence along the propagation direction of the laser signal. The linkage mechanism is used to carry the secondary imaging lens group, the laser light source, the collimating lens group, the double optical wedge prism, the rectangular slit, and the fixation light source and synchronously move the secondary imaging lens group, the laser light source, the collimating lens group, the double optical wedge prism, the rectangular slit, and the fixation light source. By setting the imaging objective lens, the laser aberration 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 mirror, 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 fundus retina, the displacement on the secondary imaging lens group exactly compensates for the refractive error of the human eye. Therefore, the refractive power information of the human eye can be further obtained according to the movement of the linkage mechanism.

[0013] In a possible implementation, 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 mirror, a third illumination lens group, and a black dot plate arranged in sequence along the propagation direction of the multispectral signal. The first multispectral light source module is used to generate the multispectral signal. The first illumination optical fiber is a fiber bundle composed of multiple optical fibers, and the shape of one end close to the second illumination lens group is annular. The black dot plate is a glass flat plate with an opaque object provided in the central area. The first illumination optical fiber in the above form can reduce the size of the light source, thereby reducing the size of the subsequent illumination light beam and lowering the cost. At the same time, the illumination optical fiber with a ring-shaped output port can obtain a ring-shaped light spot without loss of illumination energy and at a relatively low cost. Furthermore, the combination of the second illumination mirror group, the plane mirror, the third illumination mirror group, the black dot board, the beam splitter, and the first illumination mirror group can image the ring-shaped light spot output by the first illumination optical fiber on the mirror area of the hollow mirror. After being reflected by the hollow mirror, it is focused by the retina objective lens onto the pupil of the human eye to form a ring-shaped light spot at the pupil, which illuminates the fundus area after propagating through the interior of the human eye.

[0014] In a possible implementation, the multispectral optical path further includes a second multispectral light source module and a dichroic mirror. The second multispectral light source module is used to generate the multispectral signal, but the central wavelengths of all bands of the generated multispectral signal are less than the central wavelength of the dichroic mirror, while the central wavelengths of all bands of the multispectral signal generated by the first multispectral light source module are greater than the central wavelength of the dichroic mirror. The dichroic mirror is arranged 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. The dichroic mirror has a high reflectivity for light of a specific wavelength and can reflect most of the incident light with a wavelength less than its central wavelength; it has a high transmittance for light with a wavelength greater than its central wavelength, enabling the light to pass through smoothly, reducing energy loss, and increasing the variety of hyperspectral bands and improving the quality of imaging information when adding a second multispectral light source module.

[0015] In a possible implementation, the multispectral optical path further includes a second multispectral light source module, a second coupling objective lens group, a second illumination optical fiber, and a dichroic mirror. The second multispectral light source module is used to generate the multispectral signal, but the central wavelengths of all bands of the generated multispectral signal are less than the central wavelength of the dichroic mirror, while the central wavelengths of all bands of the multispectral signal generated by the first multispectral light source module are greater than the central wavelength of the dichroic mirror. The second multispectral light source module, the second coupling objective lens group, the second illumination optical fiber, and the dichroic mirror are sequentially arranged along the propagation direction of the multispectral signal generated by the second multispectral light source module, and the first illumination optical fiber, the dichroic mirror, and the second illumination mirror group are sequentially arranged along the propagation direction of the multispectral signal generated by the first multispectral light source module. The second illumination optical fiber is a fiber bundle composed of multiple optical fibers, and the shape of the end close to the dichroic mirror is ring-shaped. The dichroic mirror is configured to transmit the multi-spectral signal generated by the first multi-spectral light source module to the second illumination mirror group, and reflect the multi-spectral signal generated by the second multi-spectral light source module to the second illumination mirror group; The combination of the second illumination optical fiber and the first illumination optical fiber, under the adjustment of the dichroic mirror, not only increases the number of spectral bands, but also can form a brighter annular light spot at the pupil, which illuminates the fundus area after propagating through the human eye, further improving the quality of the imaging information.

[0016] Another technical solution of the present invention is to provide a multi-spectral fundus imaging method, including the following steps: S1: Turn on the photographing device 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 workable area of the main optical path; S2: Turn off the photographing device, make the multi-spectral optical path output a multi-spectral signal of one band signal, and at the same time make the laser fixation optical path provide a fixation object for the human eye, and output a laser signal with two laser beams; S3: Move the laser fixation optical path, obtain image information through the imaging optical path, and stop the output of the laser fixation optical path when the two laser line segments shown in the obtained image information coincide; S4: Make the multi-spectral optical path output multi-spectral signals of all band signals to obtain a fundus multi-spectral image by using the image information obtained by the imaging optical path.

[0017] The method disclosed in the present invention first captures the peripheral image of the human eye through the photographing device, and then obtains the pupil position of the human eye to confirm the position of the human eye; subsequently, a fixation object is provided for the human eye through the laser fixation optical path, thereby reducing the detection error caused by nystagmus, and outputting a laser signal with two laser beams through the laser fixation optical path. After moving the laser fixation optical path until the two laser line segments in the image information coincide, the fundus is exposed through the multi-spectral optical path, and finally the fundus image information is obtained through the imaging optical path, realizing high-power fundus multi-spectral imaging and fundus information acquisition. Therefore, in the method of the present invention, there is no need to consider the influence of too many light source types and too large light source volume on illumination, the beam shaping is simple, the adjustment ability of the human eye can be utilized to improve the quality of fundus photography. Moreover, there is no need to separately allocate a fixation light source optical path, thereby improving the illumination efficiency of the overall device and reducing the displacement of the multi-spectral fundus image. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the optical path structure included in a multi-spectral fundus imaging device disclosed in Embodiment 1 of the present invention; Figure 2 It is a schematic diagram of the distribution of the fixation light source disclosed in Embodiment 1 of the present invention; Figure 3 Schematic diagram of the structure of the first multi-spectral light source module disclosed in the first embodiment of the present invention; Figure 4 Flowchart of the method disclosed in the first embodiment of the present invention; Figure 5 Schematic diagram of the internal optical path structure of a multi-spectral fundus imaging device disclosed in the second embodiment of the present invention; Figure 6 Schematic diagram of the fixation light source distribution disclosed in the second embodiment of the present invention; Figure 7 Schematic diagram of the internal optical path structure of a multi-spectral fundus imaging device disclosed in the third embodiment of the present invention.

[0019] Explanation of reference numerals: 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 optical fiber, 10. Second illumination optical fiber, 11. Dichroic mirror, 12. Second illumination mirror group, 13. Plane mirror, 14. Third illumination mirror group, 15. Black dot board, 16. Beam splitter, 17. First illumination mirror group, 18. Hollow mirror, 19. Retinal 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 implementation manners

[0020] First of all, those skilled in the art should understand that these implementation manners are only used to explain the technical principles of the embodiments of the present application, and are not intended to limit the protection scope of the embodiments of the present application. Those skilled in the art can make adjustments according to needs to adapt to specific application scenarios.

[0021] According to the usage in the field of optics, "optical path" has two meanings: one is the forward path of light; the other is the structure formed by a combination of optical elements that can make light travel along a specified path. For the sake of unified terminology, the "optical path" mentioned in this application represents the second meaning, that is, the structure formed by a combination of optical elements that can make light travel along a specified path. In addition, the coincidence of the optical axes between the first optical element and the second optical element means that the angle (the acute angle) between the optical axis of the first optical element and the optical axis of the second optical element is not greater than 2 angular minutes, and the distance between them is not greater than 50 μm. Similarly, the coincidence of the eye axis of the human eye and the optical axis of an optical element means that the angle (the acute angle) between the eye axis of the human eye and the optical axis of an optical element is not greater than 2 angular minutes, and the distance between them is not greater than 50 μm.

[0022] In the embodiments of this application, unless otherwise clearly specified and limited, the first feature being "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature can be that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is at a higher horizontal level than the second feature. The first feature being "below", "beneath" and "underneath" the second feature can be that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is at a lower horizontal level than the second feature.

[0023] Three embodiments will be used below, and in combination with the drawings and specific examples, the technical solutions of this application will be further described in detail.

[0024] Embodiment 1:

[0025] See Figures 1 to 3 , this embodiment discloses a multi-spectral fundus imaging device, Figure 1Schematic diagram of the optical path structure of the imaging device. The imaging device includes a movable bracket, and a photographing device, a laser fixation optical path, a multispectral optical path, a main optical path, an imaging objective lens 29, a linkage mechanism 30, and an imaging optical path provided on the movable bracket. The photographing device is used to capture the peripheral image of the human eye 20 to obtain the pupil position of the human eye 20. The laser fixation optical path is movably provided 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 signals of different bands. The main optical path is used to introduce the laser signal into the human eye 20 to be reflected by the fundus of the human eye 20 to form a first reflection signal corresponding to the laser signal, and introduce the multispectral signal into the human eye 20 to be 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 the image information of the first reflection signal and the second reflection signal. Among them, the laser fixation optical path, the imaging objective lens 29, 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 reflection signal.

[0026] See Figure 1 , in this 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 illumination light source 1 and a first near-infrared camera 4, and the second photographing device includes a second near-infrared illumination light source 2 and a second near-infrared camera 3. The first near-infrared illumination light source 1 and the second near-infrared illumination light source 2 can be selected as light-emitting diodes, and their central wavelengths can be determined according to actual situations. In this embodiment, the first near-infrared illumination light source 1 is selected as a light-emitting diode with a central wavelength of 850 nm, and the second near-infrared illumination light source 2 is selected as a light-emitting diode with a central wavelength of 850 nm. Both the first near-infrared camera 4 and the second near-infrared camera 3 are infrared detectors, and are used to photograph the human eye 20 and the surroundings of the human eye 20. These two cameras rely on the light reflected by the human eye 20 from the first near-infrared illumination light source 1 and the second near-infrared illumination light source 2 to locate the pupil position of the human eye 20.

[0027] Please continue to see Figure 1, in this embodiment, the laser fixation optical path includes 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. The laser light source 24, the collimating lens group 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 group 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 780 nm, or other bands can be selected according to needs. The collimating lens group 25 is an optical unit composed of one or more spherical or aspherical lenses. The double-wedge prism 26 is a prism composed of two stacked identical triangular transparent optical materials, which is used to modulate the laser beam into a laser signal with two laser beams. This laser signal then enters the human eye 20, and finally two laser line segments appear in the image information obtained in the imaging optical path. Thus, the diopter 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.

[0028] See Figure 2 , in the field of optics, a slit usually refers to a light-blocking plate with a tiny rectangular light-transmitting hole, and its function is 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-transmitting hole. The fixation light source 28 is located outside the propagation path of the laser signal and within 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. As Figure 2 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-transmitting hole.

[0029] Please continue to see Figure 1 , in this embodiment, the main optical path includes a beam splitter 16, a first illumination lens group 17, a hollow mirror 18, and a retina objective lens 19 that docks with 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 onto the first illumination lens group 17 and transmit the multi-spectral signal onto the first illumination lens group 17. The hollow mirror 18 is arranged to reflect the laser signal and / or multi-spectral signal processed by the first illumination lens group 17 onto the retina objective lens 19, and transmit the first reflected signal and / or second reflected signal processed by the retina objective lens 19 to the imaging optical path. In Figure 1 , 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 group 17 is an optical unit composed of one or more spherical or aspherical lenses.

[0030] Please continue to see Figure 1, in this embodiment, the imaging optical path includes a secondary imaging lens group 21, a tertiary imaging lens group 22, and a detector 23 arranged in sequence along the propagation direction of the first reflection signal. The retina objective lens 19, the hollow mirror 18, and the secondary imaging lens group 21 are arranged in sequence along the propagation direction of the first reflection signal, and the optical axes of the retina objective lens 19, the hollow mirror 18, and the secondary imaging lens group 21 coincide. The secondary imaging lens group 21 is movably arranged on a movable bracket along the optical axis of the secondary imaging lens group 21. Figure 1 In [figure], the vertical dotted line on the right side of the secondary imaging lens group 21 is the image plane of the secondary imaging lens group 21.

[0031] Please continue to refer to 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 optical wedge prism 26, the rectangular slit 27, and the fixation light source 28 and synchronously move the secondary imaging lens group 21, the laser light source 24, the collimating lens group 25, the double optical wedge prism 26, the rectangular slit 27, and the fixation light source 28.

[0032] Refer to 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 optical fiber 9, a second illumination lens group 12, a plane mirror 13, a third illumination lens group 14, and a black dot plate 15 arranged in sequence 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 with different spectral bands arranged on the circuit board 5-1. The schematic structural diagram is as shown in Figure 3 . The central wavelengths of the spectral bands in this embodiment include 660nm, 740nm, 780nm, and 850nm. The first coupling objective lens group 8 is an optical unit composed of one or more spherical or aspherical lenses. The lens material can be glass or plastic, and the overall optical power is positive. The first illumination optical fiber 9 is a fiber bundle composed of multiple optical fibers, and the shape of the end close to the second illumination lens group 12 is annular, while the shape of the end close to 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 central area. Both the second illumination lens group 12 and the third illumination lens group 14 are optical units composed of one or more spherical or aspherical lenses.

[0033] Refer to Figure 4 , the following will further disclose the usage method corresponding to the multispectral fundus imaging device in this embodiment. The method includes the following steps: S1: Use a photographing device to obtain the pupil position of the human eye 20, and move 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.

[0034] Specifically, turn on the first near-infrared illumination source 1, the second near-infrared illumination source 2, the first near-infrared camera 4, and the second near-infrared camera 3. Obtain the pupil position of the human eye 20 based on the images obtained by the first near-infrared camera 4 and the second near-infrared camera 3, and move the movable bracket according to the obtained pupil position so that the optical axis of the eye of the human eye 20 coincides with the optical axis of the retinal objective lens 19 of the main optical path.

[0035] S2: Make the multi-spectral optical path output a multi-spectral signal of one band signal, and at the same time make the laser fixation optical path provide a fixation object for the human eye 20 and output a laser signal with two laser beams.

[0036] Specifically, after performing step S1, turn off the first near-infrared illumination source 1, the second near-infrared illumination source 2, the first near-infrared camera 4, and the second near-infrared camera 3, and turn on 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.

[0037] S3: Move the laser fixation optical path, obtain image information through the imaging optical path, and stop the output of the laser fixation optical path and stop moving the laser fixation optical path when the two laser line segments shown in the obtained image information coincide.

[0038] Specifically, when the two laser line segments shown in the obtained image information coincide, turn off the laser light source 24 and the fixation light source 28.

[0039] S4: Make the multi-spectral optical path output a multi-spectral signal of all band signals to obtain a fundus multi-spectral image by using the image information obtained by the imaging optical path.

[0040] Specifically, expose the 850nm, 780nm, 740nm, and 660nm multi-spectral light sources of the first multi-spectral light source module 5 in sequence, and obtain a fundus multi-spectral image through the detector 23.

[0041] The multi-spectral fundus imaging device disclosed in this embodiment can capture the peripheral image of the human eye 20 by setting up a photographing device, and then obtain the pupil position of the human eye 20 to confirm the position of the human eye 20. By setting up a laser fixation optical path, a fixation object can be provided for the human eye 20, thereby reducing the detection error caused by nystagmus. Moreover, the set laser fixation optical path can also output a laser signal with two laser beams, and the laser fixation optical path is movably arranged on a movable support along the reference axis of the laser fixation optical path. Therefore, the two output laser beams will tend to coincide in the human eye 20. This process can be collected by the set imaging optical path, and two laser line segments will be shown in the obtained image information. When these two laser line segments coincide in the image information, the fundus can be exposed through the set multi-spectral optical path, and finally fundus image information can be obtained through the imaging optical path, realizing high-power fundus multi-spectral imaging and fundus information collection. Therefore, the multi-spectral fundus imaging device in this embodiment does not need to consider the influence of too many light source types and too large light source volume 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 photography. Moreover, there is no need to separately set up a fixation light source optical path, thereby improving the illumination efficiency of the overall device and reducing the displacement existing in the multi-spectral fundus image.

[0042] Embodiment 2:

[0043] Refer to Figure 5 , this embodiment further discloses a multi-spectral fundus imaging device. Figure 5 is a schematic diagram of the optical path structure of the imaging device. The difference between this imaging device and that of Embodiment 1 is that the multi-spectral optical path of this imaging device includes a first multi-spectral light source module 5, a second multi-spectral light source module 6, a first coupling objective lens group 8, a first illumination optical fiber 9, a dichroic mirror 11, a second illumination lens group 12, a plane mirror 13, a third illumination lens group 14, and a black dot board 15. Both the first multi-spectral light source module 5 and the second multi-spectral light source module 6 are used to generate multi-spectral signals. However, the central wavelength of all bands of the multi-spectral signal generated by the second multi-spectral light source module 6 is less than the central wavelength of the dichroic mirror 11, while the central wavelength of all bands of the multi-spectral signal generated by the first multi-spectral light source module 5 is greater than the central wavelength of the dichroic mirror 11. The structures of the first coupling objective lens group 8, the first illumination optical fiber 9, the second illumination lens group 12, the plane mirror 13, the third illumination lens group 14, and the black dot board 15 are the same as those in Embodiment 1.

[0044] In this embodiment, the dichroic mirror 11 is arranged to transmit the multi-spectral signal generated by the first multi-spectral light source module 5 to the first coupling objective lens group 8, and reflect the multi-spectral signal generated by the second multi-spectral light source module 6 to the first coupling objective lens group 8. The first coupling objective lens group 8, the first illumination optical fiber 9, the second illumination lens group 12, the plane mirror 13, the third illumination lens group 14, and the black dot plate 15 are arranged in sequence along the propagation direction of the multi-spectral signal output by the dichroic mirror 11.

[0045] In this embodiment, the central wavelength of the dichroic mirror 11 is 650 nm. The central 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 central 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.

[0046] In addition, referring to 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, as Figure 6 shown, and a fixation pattern 28-2 is displayed on one of the micro displays 28-1.

[0047] In this embodiment, by setting the first multi-spectral light source module 5, the second multi-spectral light source module 6, the first coupling objective lens group 8, the first illumination optical fiber 9, the dichroic mirror 11, the second illumination lens group 12, the plane mirror 13, the third illumination lens group 14, and the black dot plate 15, the technical defect that it is difficult to balance the number of multi-spectral light sources, the light source power, and the cost in the existing multi-spectral fundus camera can be overcome. By coupling the illumination light sources of the two spectral light source modules through two coupling lens groups, there is no need to impose too many restrictions on the size and number of the multi-spectral light sources, greatly increasing the flexibility of light source selection. The multi-spectral signal output by the dichroic mirror 11 enters the first illumination optical fiber 9 after being coupled by the first coupling objective lens group 8, and the multi-spectral signal is reflected multiple times inside the first illumination optical fiber 9, which plays a role in homogenizing the light spot. Especially when using an illumination optical fiber with an annular output port, it plays a role in beam shaping, reduces the difficulty of beam shaping, easily modifies the illumination band, and expands the functions of the multi-spectral fundus camera. The rectangular slit 27 and the fundus retina of the human eye 20 are in a conjugate position. Therefore, placing the fixation light source 28 at the rectangular slit 27 can make full use of the self-adjusting function of the human eye 20 to improve the shooting effect. At the same time, it avoids adding beam splitting devices in the imaging optical path and increases the light source utilization efficiency.

[0048] Embodiment Three:

[0049] Referring to Figure 7 , this embodiment further discloses a multi-spectral fundus imaging deviceFigure 7 It is a schematic diagram of the optical path structure of the imaging device. The difference between this imaging device and that of the first embodiment is that the multi-spectral optical path of this imaging device includes a first multi-spectral light source module 5, a second multi-spectral light source module 6, a second coupling objective lens group 7, a first coupling objective lens group 8, a first illumination optical fiber 9, a dichroic mirror 11, a second illumination mirror group 12, a plane mirror 13, a third illumination mirror group 14, and a black dot board 15. Both the first multi-spectral light source module 5 and the second multi-spectral light source module 6 are used to generate multi-spectral signals. However, the central wavelengths of all bands of the multi-spectral signal generated by the second multi-spectral light source module 6 are less than the central wavelength of the dichroic mirror 11, while the central wavelengths of all bands of the multi-spectral signal generated by the first multi-spectral light source module 5 are greater than the central wavelength of the dichroic mirror 11. The structures of the first coupling objective lens group 8, the first illumination optical fiber 9, the second illumination mirror group 12, the plane mirror 13, the third illumination mirror group 14, and the black dot board 15 are the same as those in the first embodiment.

[0050] Please continue to refer to Figure 7 , in this embodiment, 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 arranged in sequence along the propagation direction of the multi-spectral signal generated by the second multi-spectral light source module 6. The first illumination optical fiber 9, the dichroic mirror 11, and the second illumination mirror group 12 are arranged in sequence 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 a fiber bundle composed of multiple optical fibers, and the shape of the end close to the dichroic mirror 11 is annular, and the shape of the end close to the second coupling objective lens group 7 is circular or square. The dichroic mirror 11 is arranged to transmit the multi-spectral signal generated by the first multi-spectral light source module 5 to the second illumination mirror group 12, and reflect the multi-spectral signal generated by the second multi-spectral light source module 6 to the second illumination mirror group 12.

[0051] In this embodiment, the central wavelength of the dichroic mirror 11 is 650 nm. The central 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 central 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.

[0052] In this embodiment, by providing the first multispectral light source module 5, the second multispectral light source module 6, the second conjugate objective lens group 7, the first conjugate objective lens group 8, the first illumination optical fiber 9, the second illumination optical fiber 10, the dichroic mirror 11, the second illumination mirror group 12, the plane mirror 13, the third illumination mirror group 14, and the black dot plate 15, the technical defect in the prior art that it is difficult to balance the number of multispectral light sources, the light source power, and the cost in a multispectral fundus camera can be overcome. By coupling the illumination light sources of two spectral light source modules with two conjugate lens groups, there is no need to impose too many 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 optical fiber 9 after being coupled by the first conjugate objective lens group 8. The multispectral signal is reflected multiple times inside the first illumination optical fiber 9 and the second illumination optical fiber 10, which plays a role in homogenizing the light spot. In particular, both the first illumination optical fiber 9 and the second illumination optical fiber 10 use illumination optical fibers with annular output ports, which plays a role in beam shaping, reduces the difficulty of beam shaping, makes it easier to modify the illumination band, and expands the functions of the multispectral fundus camera.

[0053] In the description of the embodiments of the present application, it should be noted that in the description of the present application, the terms indicating the direction or positional relationship such as "inner", "outer", etc. are based on the direction or positional relationship shown in the 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 should not be construed as a limitation to the present application.

[0054] In the description of the present application, the description with reference to terms such as "one embodiment", "some embodiments", "in this embodiment", "specific example", or "some examples" means that the specific features, mechanisms, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic expressions 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, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0055] The above is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed in the present application should be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A multispectral fundus imaging device, comprising a movable bracket, characterized in that, The imaging device further includes components disposed on the movable bracket: A photographing device for capturing a peripheral image of the human eye (20) to obtain the pupil position of the human eye (20); A laser fixation optical path, which is movably disposed on the movable bracket along the reference axis of the laser fixation optical path, for providing a fixation object for the human eye (20) and outputting a laser signal having two laser beams; A multispectral optical path for outputting a multispectral signal having signals of multiple different bands; A main optical path for introducing the laser signal into the human eye (20) to be reflected by the fundus of the human eye (20) to form a first reflection signal corresponding to the laser signal, and introducing the multispectral signal into the human eye (20) 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; Wherein, the laser fixation optical path and the main optical path are sequentially arranged along the propagation direction of the laser signal, the multispectral optical path and the main optical path are sequentially arranged along the propagation direction of the multispectral signal, and the main optical path and the imaging optical path are sequentially arranged along the propagation direction of the first reflection signal.

2. The multi-spectral fundus imaging device according to claim 1, wherein 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 illumination light source (1) and a first near-infrared camera (4), and the second photographing device includes a second near-infrared illumination light source (2) and a second near-infrared camera (3).

3. The multi-spectral fundus imaging device according to claim 2, wherein The laser fixation optical path includes 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). The laser light source (24) is used to generate a laser beam. The laser light source (24), the collimating lens group (25), the double-wedge prism (26), and the rectangular slit (27) are sequentially arranged along the propagation direction of the laser beam. The double-wedge prism (26) is used to modulate the laser beam into a laser signal having two laser beams. The fixation light source (28) is located outside the propagation path of the laser signal and within the light-receiving region of the main optical path.

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

5. The multispectral fundus imaging device according to claim 4, wherein The imaging optical path includes a secondary imaging lens group (21), a tertiary imaging lens group (22), and a detector (23) arranged in sequence along the propagation direction of the first reflection signal. The retina objective lens (19), the hollow mirror (18), and the secondary imaging lens group (21) are arranged in sequence along the propagation direction of the first reflection signal. The secondary imaging lens group (21) is movably arranged on the movable support along the optical axis of the secondary imaging lens group (21).

6. The multi-spectral fundus imaging device according to claim 5, wherein, The imaging device further includes an imaging objective lens (29) and a linkage mechanism (30) arranged on the movable support. 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. 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 optical wedge prism (26), the rectangular slit (27), and the fixation light source (28) and synchronously move the secondary imaging lens group (21), the laser light source (24), the collimating lens group (25), the double optical wedge prism (26), the rectangular slit (27), and the fixation light source (28).

7. The multi-spectral fundus imaging device according to claim 6, wherein The multi-spectral optical path includes 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 mirror (13), a third illumination lens group (14), and a black dot plate (15) arranged in sequence along the propagation direction of the multi-spectral signal. 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 the end close to the second illumination lens group (12) is annular; The black dot plate (15) is a glass flat plate with an opaque object in the central area.

8. The multi-spectral fundus imaging device according to claim 7, characterized in that, The multi-spectral optical path further includes a second multi-spectral light source module (6) and a dichroic mirror (11). The second multi-spectral light source module (6) is used to generate the multi-spectral signal, but the central wavelengths of all bands of the generated multi-spectral signal are less than the central wavelength of the dichroic mirror (11), while the central wavelengths of all bands of the multi-spectral signal generated by the first multi-spectral light source module (5) are greater than the central wavelength of the dichroic mirror (11); The dichroic mirror (11) is arranged to transmit the multi-spectral signal generated by the first multi-spectral light source module (5) to the first coupling objective lens group (8), and reflect the multi-spectral signal generated by the second multi-spectral light source module (6) to the first coupling objective lens group (8).

9. The multi-spectral fundus imaging device according to claim 7, characterized in that, The multi-spectral optical path further includes 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). The second multi-spectral light source module (6) is used to generate the multi-spectral signal, but the central wavelengths of all bands of the generated multi-spectral signal are less than the central wavelength of the dichroic mirror (11), while the central wavelengths of all bands of the multi-spectral signal generated by the first multi-spectral light source module (5) are greater than the central 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). 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 the end close to the dichroic mirror (11) is annular. The dichroic mirror (11) is arranged to transmit the multi-spectral signal generated by the first multi-spectral light source module (5) to the second illumination lens group (12), and reflect the multi-spectral signal generated by the second multi-spectral light source module (6) to the second illumination lens group (12).

10. A multispectral fundus imaging method, characterized in that, Applicable to the multi-spectral fundus imaging device according to any one of claims 1-9, including the following steps: S1: Obtain the pupil position of the human eye (20) through a photographing device, and move the movable bracket according to the obtained pupil position to make the human eye (20) located in the workable area of the main optical path. S2: Make the multi-spectral optical path output a multi-spectral signal of one band, and at the same time make the laser fixation optical path provide a fixation object for the human eye (20) and output a laser signal with two laser beams. S3: Move the laser fixation optical path, obtain image information through the imaging optical path, and stop the output of the laser fixation optical path when the two laser line segments shown in the obtained image information coincide. S4: Make the multi-spectral optical path output a multi-spectral signal of all bands to obtain a multi-spectral fundus image by using the image information obtained by the imaging optical path.

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