A portable multi-spectral fundus camera device with stray light elimination

Abstract

A portable stray light elimination multi-spectral fundus camera device comprises an illumination system, an imaging system and an image acquisition device located on the same optical axis; the illumination system comprises a light source, a scattering plate, a light collecting lens, a first polarizing plate, a condensing lens and a beam splitter arranged in sequence; the imaging system comprises a front objective lens, a second polarizing plate and a relay lens arranged in sequence; the first polarizing plate and the second polarizing plate are arranged for vertical polarization; the beam splitter is located between the second polarizing plate and the front objective lens, and the image acquisition device is located outside the front objective lens; the light source emits initial light, which passes through the scattering plate, the light collecting lens, the first polarizing plate and the condensing lens in sequence, reaches the beam splitter, and then reflects to the front objective lens, and then enters the fundus; the reflected light of the fundus reaches the beam splitter through the front objective lens, and then is transmitted to the second polarizing plate, and then enters the image acquisition device through the relay lens. The overall structure of the present invention is simple and the size is small, and the cost is low, which is suitable for promotion.

Description

Technical Field

[0001] The invention relates to the field of fundus cameras, in particular to a portable stray light elimination multi-spectral fundus camera device. Background Art

[0002] The retina of the human eye, also known as the fundus, is an important part of the human eye. If the eyes are used improperly or there are systemic diseases such as hypertension, diabetes, thrombosis, etc., a series of fundus lesions will occur. In the early stages of these diseases, the eyes generally have no obvious symptoms and are not easy to detect. Therefore, fundus examination is of great significance in clinical practice. Through fundus examination, the specific conditions of the patient's fundus can be observed more clearly, which can help to timely discover and treat many diseases.

[0003] Currently, the commonly used optical imaging equipment for observing the human eye fundus mainly includes fundus cameras, ophthalmoscopes, OCT, etc. Fundus cameras are widely used in hospitals due to their simple operation and high imaging quality. Since the human eye itself does not emit light, the fundus camera system includes a lighting system and an image acquisition system to illuminate the human eye fundus and image the fundus.

[0004] However, the existing fundus camera device lighting system usually includes multiple lens groups, resulting in the existing fundus camera lighting device being complex in structure, large in size and high in cost, which brings a lot of inconvenience to fundus examination for ordinary people; the existing fundus examination instruments usually have problems such as high difficulty in operation and high price, which cause certain troubles for fundus examination for ordinary people; some fundus examination devices have problems such as serious stray light interference, which seriously affects the imaging quality; and most fundus cameras can only collect fundus information of a single layer due to the single wavelength of the light source, resulting in the inability to perform detailed analysis of the fundus condition; therefore, providing a portable stray light-eliminating multi-spectral fundus camera device with a relatively simple structure, no stray light interference, small size and low cost has become a research focus of technical personnel in this field. Summary of the invention

[0005] The main purpose of the present invention is to overcome the above-mentioned defects in the prior art and to provide a portable stray light elimination multi-spectral fundus camera device, which has a simple structure, no stray light interference problem, and is small in size and low in cost.

[0006] The present invention adopts the following technical solution:

[0007] A portable stray light elimination multispectral fundus camera device comprises an illumination system, an imaging system and an image acquisition device located on the same optical axis; the characteristics are as follows: the illumination system comprises a light source, a scattering plate, a light collecting lens, a first polarizing plate, a condensing lens and a beam splitter arranged in sequence; the imaging system comprises a front objective lens, a second polarizing plate and a relay lens arranged in sequence; the first polarizing plate and the second polarizing plate are arranged for vertical polarization; the beam splitter is located between the second polarizing plate and the front objective lens, and the image acquisition device is located outside the front objective lens; the light source emits initial light, which passes through the scattering plate, the light collecting lens, the first polarizing plate and the condensing lens in sequence, reaches the beam splitter, is reflected to the front objective lens, and then enters the fundus; the reflected light of the fundus reaches the beam splitter through the front objective lens, is transmitted to the second polarizing plate, and then enters the image acquisition device through the relay lens.

[0008] Preferably, the beam splitter is a semi-transparent and semi-reflective mirror.

[0009] Preferably, the wavelength range of the spectroscope covers all wavelength ranges of the light source.

[0010] Preferably, a light source controller is further included, and the light source controller is connected to the light source to control it to achieve multi-spectrum lighting.

[0011] Preferably, the light source is a plurality of LEDs with different wavelengths arranged alternately to form a ring.

[0012] Preferably, the light source position is conjugate with the pupil.

[0013] Preferably, the image acquisition device is a mobile phone or a camera.

[0014] Preferably, a cage-type structure is further included, which is provided with a plurality of mirror frames, and the plurality of mirror frames are respectively installed with the scattering plate, the light collecting lens, the first polarizer, the condensing lens, the second polarizer and the relay lens, and adjacent mirror frames are connected by connecting rods.

[0015] Preferably, the cage structure is further provided with a cage cube, and the beam splitter is mounted on the cage cube.

[0016] It can be seen from the above description of the present invention that, compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. The device of the present invention has an illumination system including a light source, a scattering plate, a light collecting lens, a first polarizing plate, a condensing lens and a beam splitter arranged in sequence, and an imaging system including a front objective lens, a second polarizing plate and a relay lens arranged in sequence. The number of imaging lenses is small, and the mechanical structure is small. Compared with the existing fundus camera device, the overall structure of the device is relatively simple and the size is small, and the operation is more convenient.

[0018] 2. The device of the present invention sets the first polarizer and the second polarizer to vertical polarization, and adopts vertical polarization technology to eliminate illumination stray light. The light source adopts a ring light design to eliminate corneal reflected light, which effectively solves the stray light interference problem of current fundus cameras.

[0019] 3. The light source of the device of the present invention is LED light, the cost of which is much lower than the cost of the existing light source used in multi-spectral imaging, so that the cost of the fundus camera device is greatly reduced;

[0020] 4. The device of the present invention can realize imaging of different fundus layers, so as to facilitate detailed analysis of fundus information. In addition, the multi-spectral light source of the present invention is convenient to manufacture and has low cost, and is suitable for promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The main structure diagram of the device of the present invention;

[0022] Figure 2 This is a schematic diagram of the optical path principle of the device of the present invention;

[0023] Figure 3 It is a schematic diagram of the overall process of the device of the present invention;

[0024] Figure 4 This is a front view of the light source of the device of the present invention;

[0025] in:

[0026] 1. Light source controller, 2. Light source, 3. Scattering plate, 4. Collecting lens, 5. First polarizer, 6. Condensing lens, 7. Beam splitter, 8. Front objective lens, 9. Second polarizer, 10. Relay lens, 11. Image acquisition device, 12. Cage structure, 13. Mirror frame, 14. Cage plate adapter, 15. Connecting rod, 16. Cage cube, 17. Fundus.

[0027] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. DETAILED DESCRIPTION

[0028] The present invention is further described below through specific implementation modes.

[0029] In the present invention, the terms "first", "second", "third", etc. are only used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence, nor can they be understood as indicating or implying relative importance. In the description, the directions or positional relationships indicated by "upper", "lower", "left", "right", "front", and "back" are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and are not intended to indicate or imply that the device referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the scope of protection of the present invention. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0030] In addition, in the description of this application, unless otherwise specified, "plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the associated objects are in an "or" relationship.

[0031] A portable stray light elimination multi-spectral fundus camera device includes an illumination system, an imaging system, and an image acquisition device 11 located on the same optical axis. The illumination system includes a light source 2, a scattering plate 3, a light collecting lens 4, a first polarizing plate 5, a condensing lens 6, and a beam splitter 7 arranged in sequence; the imaging system includes a front objective lens 8, a second polarizing plate 9, and a relay lens 10 arranged in sequence. The first polarizing plate 5 and the second polarizing plate 9 are arranged in a vertical polarization configuration; the beam splitter 7 is located between the second polarizing plate 9 and the front objective lens 8, and the image acquisition device 11 is located outside the front objective lens 8. The light source 2 emits an initial light, which passes through the scattering plate 3, the light collecting lens 4, the first polarizing plate 5, and the condensing lens 6 in sequence, and is reflected to the front objective lens 8 after reaching the beam splitter 7, and then enters the fundus 17. The reflected light of the fundus 17 reaches the beam splitter 7 through the front objective lens 8, is transmitted to the second polarizing plate 9, and then enters the image acquisition device 11 through the relay lens 10.

[0032] The light source 2 is a plurality of LEDs of different wavelengths arranged alternately to form a ring, and the position of the light source 2 is conjugate with the pupil to eliminate the reflected stray light of the cornea. For example, the LED ring light source may include LED lamp beads 3a of three wavelength ranges, and the LED lamp beads 3a of different wavelength ranges are arranged alternately to form a ring.

[0033] The portion of the illumination light near the optical axis usually illuminates the center of the human cornea, causing the imaging system to form a ghost image when imaging the fundus 17 of the human eye. In the embodiment of the present application, the annular light source 2 causes the illumination light to form an annular light spot at the cornea of ​​the human eye, suppressing the formation of ghost images when the imaging system images the fundus 17, which is beneficial to imaging the fundus 17 of the human eye. It should be noted that the specific parameters of the conjugation of the annular light source 2 and the pupil are not limited in the present application, and it depends on the specific situation.

[0034] The device further comprises a light source controller 1 which is connected to a light source 2. The light source controller 1 can control the switches of LED lamp beads in different wavelength ranges respectively to realize multi-spectrum fundus illumination.

[0035] Furthermore, the spectroscope 7 is a semi-transparent and semi-reflective mirror. The principle of the spectroscope 7 is to use a dispersion element (prism or grating) to decompose white light into monochromatic light of different wavelengths, and to form a continuous visible light spectrum. In the embodiment of the present application, the wavelength range of the spectroscope 7 should cover all wavelength ranges of the light source 2, which helps to better realize the multi-spectrum illumination of the light source 2. Regarding the specific wavelength range of the light source 2 and the spectroscope 7, the present application does not limit this, and it depends on the specific situation.

[0036] It also includes a cage structure 12, which is provided with a plurality of mirror frames 13, and the plurality of mirror frames 13 are respectively installed with a scattering plate 3, a light collecting lens 4, a first polarizing plate 5, a focusing lens 6, a second polarizing plate 9 and a relay lens 10, etc., and adjacent mirror frames 13 are connected by connecting rods 15. The cage structure 12 is also provided with a cage cube 16, and the beam splitter 7 is installed on the cage cube 16, and the cage cube 16 and the mirror frame 13 are also connected by connecting rods 15. The mirror frame 13 of the present invention is a rotatable mirror frame, which allows the lens, polarizing plate, and scattering plate 3 to change their axial positions freely, and can also have different sizes, for example, it can include a 1-inch lens frame and a 2-inch lens frame, and the mirror frames 13 of different sizes can be connected through a cage plate adapter 14.

[0037] The first polarizer 5 and the second polarizer 9 of the present invention are mechanical polarizers, both of which are placed in a rotatable frame 13. The frame 13 is rotated so that the first polarizer 5 and the second polarizer 9 are completely vertically polarized to block the initial light of the light source 2 in the illumination light path from being reflected toward the image acquisition device 11 by the beam splitter 7, and only the light reflected toward the fundus 17 by the beam splitter 7 and then reflected back to the image acquisition device 11 is retained.

[0038] The light reflected by the fundus 17 is diffusely reflected light, but most of the light reflected by the cornea is specularly reflected. When this part of the cornea reflected light reaches the beam splitter 7 through the front objective lens 8 and is transmitted through the second polarizer 9, it will still be blocked by the second polarizer 9. Therefore, in the embodiment of the present application, the vertical polarization technology can not only eliminate the illumination stray light, but also eliminate the cornea reflected light.

[0039] In the present invention, the collecting lens 4, the focusing lens 6, the front objective lens 8, and the relay lens 10 can be used as an imaging lens group, and the optical centers of the light source 2, the scattering plate 3, the beam splitter 7, the first polarizer 5, the imaging lens group, the second polarizer 9, and the image acquisition device 11 are all located on the same optical axis.

[0040] In the illumination optical path of the illumination system of the present invention, the light source controller 1 adjusts the emission wavelength of the light source 2, and the light source 2 emits initial light, which passes through the scattering plate 3. The scattering plate 3 is responsible for homogenizing the initial light emitted by the light source 2, and then passes through the collecting lens 4, the first polarizing plate 5 and the focusing lens 6 in sequence, reaches the beam splitter 7, and then reflects to the front objective lens 8, and finally enters the fundus 17. In the imaging optical path of the imaging system, the light reflected from the fundus 17 reaches the beam splitter 7 through the front objective lens 8, and then transmits to the second polarizing plate 9, and enters the image acquisition device 11 through the relay lens 10. In the illumination optical path, the present invention uses the reflection function of the beam splitter 7; and uses the transmission function of the beam splitter 7 in the imaging optical path.

[0041] The image acquisition device 11 is a mobile phone or a camera. The device of the present invention can also be combined with AI disease detection. The fundus images acquired by the image acquisition device 11 can be further imported into the neural network for training to achieve fundus disease classification detection based on deep learning, which will provide a certain reliable basis for the patient's eye disease judgment and clinical diagnosis. It should be noted that the above-mentioned image transmission method and the algorithm architecture of the neural network are not limited in this application, and it depends on the specific situation.

[0042] Furthermore, in the embodiment of the present application, the light from the light source 2 when reaching the beam splitter 7 should be incident on the surface of the beam splitter 7 at 45 degrees to prevent the light from deviating from the optical axis; the image acquisition device 11 and the eye should be positioned appropriately so that the light can reach the fundus 17 more accurately, which also helps the image acquisition device 11 to obtain a clearer image of the fundus 17.

[0043] The device of the present invention has fewer imaging lenses and a smaller mechanical structure, so that the overall structure of the device is relatively simple and smaller in size compared to existing fundus camera devices, and the operation is more convenient; the annular light design can eliminate corneal reflected light, and the vertical polarization technology can eliminate illumination stray light, which well solves the stray light interference problem of current fundus cameras. Since the light source 2 is an LED lamp, the cost is much lower than the cost of the existing light source 2 used in multi-spectral imaging, which greatly reduces the cost of the device. In addition, the multi-spectral light source can realize imaging of different layers of the fundus 17, and can perform detailed analysis of the fundus information. In summary, the portable stray light elimination multi-spectral fundus camera device provided by the present invention is suitable for application and promotion.

[0044] The above is only a specific implementation of the present invention, but the design concept of the present invention is not limited thereto. Any non-substantial changes to the present invention using this concept shall be deemed as an infringement of the protection scope of the present invention.

Claims

1. A portable stray light elimination multispectral fundus camera device, comprising an illumination system, an imaging system and an image acquisition device located on the same optical axis; characterized in that: The illumination system comprises a light source, a scattering plate, a light collecting lens, a first polarizing plate, a condensing lens and a beam splitter which are arranged in sequence; the imaging system comprises a front objective lens, a second polarizing plate and a relay lens which are arranged in sequence; the first polarizing plate and the second polarizing plate are arranged for vertical polarization; the beam splitter is located between the second polarizing plate and the front objective lens, and the image acquisition device is located outside the front objective lens; the light source emits initial light, which passes through the scattering plate, the light collecting lens, the first polarizing plate and the condensing lens in sequence, reaches the beam splitter, is reflected to the front objective lens, and then enters the fundus; the reflected light from the fundus reaches the beam splitter through the front objective lens, is transmitted to the second polarizing plate, and then enters the image acquisition device through the relay lens; It also includes a cage-type structure, which is provided with a plurality of frames, on which the scattering plate, the collecting lens, the first polarizer, the focusing lens, the second polarizer and the relay lens are respectively installed, and adjacent frames are connected by connecting rods; the first polarizer and the second polarizer are mechanical polarizers, both of which are placed in a rotatable frame, and the first polarizer and the second polarizer are completely vertically polarized by rotating the frame to block the initial light of the light source in the illumination light path from being reflected by the beam splitter to the image acquisition device, and only the light reflected by the beam splitter to the fundus and then reflected back to the image acquisition device is retained.

2. A portable stray light elimination multi-spectral fundus camera device as claimed in claim 1, characterized in that: The beam splitter is a semi-transparent and semi-reflective mirror.

3. The portable stray light elimination multi-spectral fundus camera device as claimed in claim 1, characterized in that: The wavelength range of the spectroscope covers all wavelength ranges of the light source.

4. The portable stray light elimination multi-spectral fundus camera device as claimed in claim 1, characterized in that: Also included is a light source controller, which is connected to the light source to control it to achieve multi-spectrum lighting.

5. The portable stray light elimination multi-spectral fundus camera device as claimed in claim 1, characterized in that: The light source is a plurality of LEDs with different wavelengths arranged alternately to form a ring.

6. A portable stray light elimination multi-spectral fundus camera device as claimed in claim 5, characterized in that: The light source position is conjugate with the pupil.

7. The portable stray light elimination multi-spectral fundus camera device according to claim 1, characterized in that: The image acquisition device is a mobile phone or a camera.

8. The portable stray light elimination multi-spectral fundus camera device as claimed in claim 1, characterized in that: The cage structure is further provided with a cage cube, and the beam splitter is mounted on the cage cube.

Images