Fundus fluorescence radiography equipment and method

Abstract

The invention belongs to the technical field of ophthalmology medical equipment, and relates to fundus fluorescence radiography equipment which comprises an eyepiece, an automatic eye searching module, an illumination diaphragm, a rotating speed modulation module, a dichroscope, an automatic focusing and fixation module, a function switching module, a rotating speed recording module, an imaging lens group and an imaging receiving module. Automatic eye searching modules are arranged on the two sides of the eyepiece, an illumination diaphragm, a dichroscope, a function switching module, an imaging lens group and an imaging receiving module are sequentially arranged right in front of the eyepiece, a rotating speed modulation module is arranged on the side portion of the illumination diaphragm, a rotating speed recording module is arranged on the side portion of the function switching module, and the rotating speed recording module is connected with the dichroscope. And the automatic focusing and fixation module is reflected by the dichroscope and then acts on human eyes through the illumination diaphragm and the eyepiece in sequence. According to the fundus fluorescence radiography equipment, various fundus examination functions such as FFA, ICGA, FAF, red-free photographing and common fundus color photograph are integrated, function switching is completed in the equipment, and additional configuration is not needed.

Description

Technical Field

[0001] The invention belongs to the technical field of ophthalmic medical equipment, and relates to a measurement technology, in particular to a fundus fluorescein angiography device and method. Background Art

[0002] Fundus fluorescein angiography is an important examination technique in the field of ophthalmology. Its principle is to quickly inject a special contrast agent from the vein, which can develop in the fundus blood vessels. By using an angiography machine or a fundus camera, the developed image can be recorded and then analyzed for fundus diseases. After the contrast agent enters the fundus blood vessels through the blood circulation, the fundus can be photographed through the pupil. The doctor will analyze the fundus disease based on the developed image, such as judging whether there is blockage of the retinal artery and vein, vascular leakage, macula, etc.

[0003] With the continuous development of ophthalmology and the continuous advancement of technology, fundus fluorescence angiography technology is subdivided into multiple branches such as fluorescein fundus angiography (FFA), indocyanine green angiography (ICGA), fundus autofluorescence (FAF), etc. Each of the three has its own advantages and the results are complementary. If all the fluorescence functions are integrated into one, it will be a great challenge for the structural design of the equipment.

[0004] Existing fundus fluorescein angiography equipment is mainly based on two technologies:

[0005] One is based on the principle of laser confocal scanning ophthalmoscope. Devices such as Heidelberg Spectralis HRA and OPTOSCalifornia use laser as the excitation light source, which is expensive and requires a built-in laser scanning component. The bandwidth of the laser is narrow, and the bandwidth range is too narrow or too wide due to the manufacturing process. It is difficult to adjust the excitation light source to the state of the best fluorescence image. Each fundus fluorescence angiography function requires the setting of a laser with a corresponding excitation wavelength. When multiple functions are integrated, the optical design complexity of the device is greatly increased, and the cost of the device is also greatly increased, making it difficult to popularize.

[0006] Another type of equipment is based on fundus camera technology, such as the fundus fluorescein angiography machine produced by Topcon, which uses halogen lamps or xenon lamps as excitation light sources. The light source has high power consumption, complex installation process, high maintenance cost, short service life, and high replacement frequency. In addition, the device uses the optical design of a traditional fundus camera and adopts a black dot plate as a component to eliminate stray light reflected by the system. That is, a circular light-blocking aperture is set at the conjugate position of the stray light reflection surface so that stray light cannot pass through and imaging light can partially pass through. This solution causes the brightness of the captured image to be uneven, and the central area is dark, requiring software post-processing.

[0007] Therefore, it is necessary to design a fundus fluorescein angiography device that integrates all fluorescence functions. Summary of the invention

[0008] The purpose of the present invention is to overcome the deficiencies of the prior art and to provide a multifunctional fundus fluorescein angiography device with reasonable structural design, low cost and long life cycle.

[0009] The present invention solves the technical problem by the following technical solutions:

[0010] A fundus fluorescein angiography device, characterized in that it includes an eyepiece, an automatic eye-finding module, an illumination aperture, a speed modulation module, a dichroic mirror, an automatic focus and fixation module, a function switching module, a speed recording module, an imaging lens group and an imaging receiving module. The automatic eye-finding module is symmetrically arranged on both sides of the eyepiece, and the illumination aperture, dichroic mirror, function switching module, imaging lens group and imaging receiving module coaxially therewith are arranged in sequence from back to front directly in front of the eyepiece. A speed modulation module is arranged on the side of the illumination aperture, and a speed recording module is arranged on the side of the function switching module. The automatic focus and fixation module acts on the human eye through the illumination aperture and the eyepiece in sequence after being reflected by the dichroic mirror.

[0011] Moreover, the illumination aperture is rotatably arranged at the center of the optical axis, and the rotation speed is controlled by a rotation speed modulation module. A light-blocking area and a light-transmitting area are arranged on the illumination aperture. The back of the light-blocking area is a conical surface, and an irregular pattern that can reduce light reflection is engraved on the conical surface.

[0012] Moreover, the irregular pattern capable of reducing light reflection is a matte thread.

[0013] Furthermore, a light absorbing material is sprayed on the irregular pattern of the conical surface.

[0014] Moreover, the minimum area of ​​the light blocking region of the illumination aperture is the minimum area required to eliminate reflected stray light.

[0015] Moreover, the function switching module is rotatably arranged on the center of the optical axis, and the rotation speed is recorded in real time by the rotation speed recording module. The function switching module includes an illumination switching component, an illumination filter component, an illumination lamp PCB and an imaging filter component which are arranged in sequence from the back to the front. A through hole is arranged at the center position of the illumination switching component, the illumination filter component and the illumination lamp PCB;

[0016] A light-blocking area and a light-transmitting area are provided on the lighting switching assembly;

[0017] N filter areas of equal area are arranged on the illumination filter component, and an illumination filter is arranged on each filter area, and the area of ​​the filter area is adapted to the area of ​​the light-transmitting area on the illumination switching component;

[0018] The lighting lamp PCB is composed of a plurality of full-spectrum white light LEDs closely arranged on the circuit board, and a side of the lighting lamp PCB on which the full-spectrum white light LEDs are arranged faces the lighting filter component;

[0019] Functional imaging filters are evenly spaced along the circumference of the imaging filter component. The size of each functional imaging filter is the same as the through hole. The center of the functional imaging filter below is rotated to coincide with the optical axis, and the corresponding functional imaging filter is switched as the position of the lighting switching component changes.

[0020] Moreover, the imaging receiving module is a planar array photoelectric converter.

[0021] A fundus fluorescein angiography method, characterized in that it specifically comprises the following steps:

[0022] Step 1, moving the fundus fluorescein angiography device to a reset position via a three-dimensional platform;

[0023] Step 2: confirm the function to be run on the fundus fluorescein angiography device, and the internal function switching module of the fundus fluorescein angiography device switches the illumination switching component, the illumination filter component and the imaging filter component to corresponding positions, and keeps the relative positions fixed and rotates along the optical axis;

[0024] Step 3, start measurement, the automatic eye-finding module moves the fundus fluorescein angiography device to the front of the eye to be measured, and gradually moves it to the working position;

[0025] Step 4, the auto-focus and fixation modules are turned on to stabilize the visual axis direction of the eye being tested, and the auto-focus makes the image clear;

[0026] Step 5: If the image is normal, the image is captured normally; if stray light appears in the image, the speed recording module feeds back to the speed modulation module for speed matching adjustment, so that the illumination aperture and the function switching module keep rotating synchronously at the best matching position, and then the image is captured;

[0027] Step 6: After the acquisition is completed, image analysis is performed and the device returns to the reset position.

[0028] The advantages and beneficial effects of the present invention are:

[0029] This fundus fluorescence angiography device uses full-spectrum LEDs instead of halogen lamps or laser light sources, with uniform spectrum, long device life, high stability and low cost;

[0030] This fundus fluorescence angiography device uses an optimized feedback-type stray light elimination design to ensure that fundus fluorescence angiography is not affected by external factors, the image brightness is uniform and stable, and the image details are not distorted;

[0031] This fundus fluorescein angiography device integrates multiple fundus examination functions such as FFA, ICGA, FAF, red-free photography and ordinary fundus color photography. Function switching is completed inside the device and no additional configuration is required. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the structural principle of the present invention;

[0033] Figure 2 is a schematic structural diagram of the illumination aperture of the present invention;

[0034] Figure 3 It is a structural schematic diagram of the function switching module of the present invention;

[0035] Figure 4 It is a structural schematic diagram of the lighting switching assembly of the present invention;

[0036] Figure 5 is a schematic diagram of the structure of the illumination filter assembly of the present invention;

[0037] Figure 6 This is a schematic diagram of the structure of the lighting lamp PCB of the present invention;

[0038] Figure 7 It is a schematic structural diagram of the imaging filter assembly of the present invention.

[0039] Reference numerals

[0040] 1-human eye, 2-automatic eye-finding module, 3-eyepiece, 4-illumination aperture, 5-speed modulation module, 6-dichroic mirror, 7-autofocus and fixation module, 8-function switching module, 9-speed recording module, 10-imaging lens group, 11-imaging receiving module, 12-illumination switching component, 13-illumination filter component, 14-illumination lamp PCB, 15-imaging filter component, 16-light blocking area, 17-light passing area. DETAILED DESCRIPTION

[0041] The present invention is further described in detail below through specific examples. The following examples are only illustrative and not restrictive, and the protection scope of the present invention cannot be limited thereto.

[0042] like Figure 1As shown, a fundus fluorescein angiography device is arranged on a three-dimensional platform that can move along three directions of X, Y, and Z, and is used for photographing and recording fundus fluorescein angiography of a human eye 1. Its innovation lies in: comprising an eyepiece 3, an automatic eye-finding module 2, an illumination aperture 4, a speed modulation module 5, a dichroic mirror 6, an automatic focus and fixation module 7, a function switching module 8, a speed recording module 9, an imaging lens group 10 and an imaging receiving module 11, and automatic eye-finding modules are symmetrically arranged on both sides of the eyepiece. The automatic eye-finding module is used to calculate the relative position information of the human eye and the device in real time, and the three-dimensional platform is fed back according to the position information to adjust the position in the three directions of X, Y, and Z to achieve the adjustment of the working position of the device; Directly in front of the mirror, from back to front, there are arranged coaxial illumination aperture, dichroic mirror, function switching module, imaging lens group and imaging receiving module. The illumination aperture and function switching module can rotate along the optical axis center of the device. A speed modulation module for controlling the rotation speed is arranged on the side of the illumination aperture. A speed recording module for recording the rotation speed is arranged on the side of the function switching module. The autofocus and fixation module projects autofocus beacon and fixation pattern to the human eye through the illumination aperture and the eyepiece in turn after being reflected by the dichroic mirror, so as to compensate for the refractive error of different subjects' eyes and obtain the best fundus image. The fixation pattern can stabilize the visual axis direction of the subject and ensure the quality of the fundus image.

[0043] like Figure 2 As shown, a light-blocking area 16 and a light-transmitting area 17 are provided on the illumination aperture. According to the optical design of the fundus fluorescein angiography device, the minimum area of ​​the light-blocking area of ​​the illumination aperture is determined by the size of the reflected stray light area superimposed on the fundus image collected by the imaging receiving module. In order to improve the utilization rate of the illumination light, the light-blocking area should be set to a minimum area that satisfies the elimination of reflected stray light.

[0044] like Figure 2 As shown, the back of the light-blocking area is a conical surface, the slope of which is selected according to the simulation results to minimize the light reflected by the light-blocking area and entering the imaging system, and an irregular pattern that can reduce light reflection is engraved on the conical surface. The irregular pattern can be a matte thread or other irregular pattern that can reduce light reflection.

[0045] In order to further reduce the reflection of the illumination light, light absorbing material is sprayed on the irregular pattern of the conical surface.

[0046] The purpose of arranging the irregular pattern that can reduce light reflection on the conical surface and arranging the light absorbing material on the irregular pattern is to eliminate the reflected stray light formed by the functional illumination light on the rear surface of the illumination aperture to avoid affecting the imaging quality.

[0047] like Figure 3-Figure 7As shown, the function switching module includes a lighting switching component 12, a lighting filter component 13, a lighting lamp PCB 14, and an imaging filter component 15, which are arranged in sequence from back to front, and through holes are arranged at the center positions of the lighting switching component, the lighting filter component, and the lighting lamp PCB.

[0048] The lighting switch component, lighting filter component, and lighting lamp PCB are closely arranged, the filter center coincides with the optical axis, and switches to the corresponding functional imaging filter as the position of the lighting switch component changes. The function switching module can rotate along the center of the device optical axis, and the speed is recorded in real time by the speed recording module.

[0049] The lighting switching component is provided with a light blocking area and a light passing area;

[0050] The lighting filter component is provided with N filter areas of equal area. Different lighting filters can be set according to different functions and requirements for lighting light bands. The area of ​​the filter area is adapted to the area of ​​the light-transmitting area on the lighting switching component. In this embodiment, the lighting filters include FFA lighting filters, ICGA lighting filters, FAF lighting filters, red-free filters, Color lighting filters and ordinary filters, and each lighting filter is a fan-shaped structure.

[0051] The lighting lamp PCB 14 is provided with closely arranged full-spectrum white light LEDs, which have uniform spectral components and wide band coverage. The lighting light is divided into N functional lighting lights of different bands through the lighting filter component. The light-passing area of ​​the lighting switching component allows one of the N functional lighting lights to pass through, and the light-blocking area blocks the lighting lights of other functions. The lighting switching component realizes the switching of functional lighting lights by changing the relative positions of the light-passing area, the lighting filter component and the lighting lamp PCB.

[0052] Functional imaging filters are evenly spaced along the circumference of the imaging filter component. In this embodiment, the functional imaging filters include FFA functional imaging filters, ICGA functional imaging filters, FAF functional imaging filters, red-free functional filters, Color functional imaging filters and ordinary functional filters. The size of each functional imaging filter is the same as the through hole. The center of the functional imaging filter below is rotated to coincide with the optical axis, and is switched to the corresponding functional imaging filter as the position of the lighting switching component changes.

[0053] When the device determines the function to be run, the lighting switching component and the imaging filter component switch to the corresponding functional position. The functional lighting light on the lighting lamp PCB is emitted by the function switching module, enters the human eye through the dichroic mirror, the lighting aperture, and the eyepiece, and the illuminated fundus forms an imaging light that returns to the device, passes through the eyepiece, the imaging aperture, the dichroic mirror, the through hole, the functional imaging filter and the imaging lens group, and is collected by the imaging receiving module to form an image.

[0054] The center of the functional illumination light deviates from the main optical axis of the equipment to form off-axis illumination, in which the functional illumination light will produce reflected stray light on the front and back surfaces of the eyepiece. The light-blocking part of the illumination aperture is set on the light path of the reflected stray light to avoid the formation of interfering bright spots on the image. The light-transmitting area illuminates the fundus through the functional illumination light, and the imaging light stimulated by the fundus returns to the optical system to form an image.

[0055] The functional illumination light is off-axis illumination. To ensure uniform brightness of the collected image, the function switching module rotates at a constant speed along the optical axis, and the speed is recorded in real time by the speed recording module. The illumination aperture keeps a fixed relative position with the function switching module and rotates with it, and the speed is controlled by the speed modulation module. The exposure time of the imaging receiving module is T, and the relationship between the speed w and the exposure time can be expressed by the following formula:

[0056] T=N / w

[0057] Where N is the number of rotations and can only be a positive integer;

[0058] During the exposure time of the image, the illumination aperture and the function switching module are kept in a fixed relative position and rotated for an integer number of cycles to ensure that the image brightness is uniform and stable.

[0059] The function switching module will inevitably be affected by external factors during actual operation, causing the rotation speed to fluctuate, resulting in a change in the relative position between the illumination aperture and the function switching module. At this time, the blocked reflected stray light reappears, affecting the image quality. The acquired fundus image is subjected to feature pattern recognition. When an abnormal highlight saturation area appears on the image, it is judged as a speed mismatch, and a feedback signal is sent. The speed of the function switching module recorded in real time by the speed recording module is fed back to the speed modulation module that controls the speed of the illumination aperture, and the speed of the illumination aperture is adjusted until the feedback signal of the image feature pattern recognition disappears. The illumination aperture restores its relative position with the function switching module, and the equipment works normally. The overall process forms a closed-loop feedback adjustment without the need for manual intervention, which improves the overall stability of the equipment.

[0060] The speed recording module and the speed modulation module can be speed controllers such as electronic encoders or photoelectric encoders. The imaging receiving module can be CMOS, CCD or other area array photoelectric conversion devices.

[0061] A fundus fluorescein angiography method, the innovation of which is that it specifically comprises the following steps:

[0062] Step 1, moving the fundus fluorescein angiography device to a reset position via a three-dimensional platform;

[0063] Step 2: confirm the function to be run on the fundus fluorescein angiography device, and the internal function switching module of the fundus fluorescein angiography device switches the illumination switching component, the illumination filter component and the imaging filter component to corresponding positions, and keeps the relative positions fixed and rotates along the optical axis;

[0064] Step 3, start measurement, the automatic eye-finding module moves the fundus fluorescein angiography device to the front of the eye to be measured, and gradually moves it to the working position;

[0065] Step 4, the auto-focus and fixation modules are turned on to stabilize the visual axis direction of the eye being tested, and the auto-focus makes the image clear;

[0066] Step 5: If the image is normal, the image is captured normally; if stray light appears in the image, the speed recording module feeds back to the speed modulation module for speed matching adjustment, so that the illumination aperture and the function switching module keep rotating synchronously at the best matching position, and then the image is captured;

[0067] Step 6: After the acquisition is completed, image analysis is performed and the device returns to the reset position.

[0068] Although the embodiments and drawings of the present invention are disclosed for illustrative purposes, those skilled in the art will appreciate that various substitutions, changes and modifications are possible without departing from the spirit and scope of the present invention and the appended claims. Therefore, the scope of the present invention is not limited to the contents disclosed in the embodiments and drawings.

Claims

1. A fundus fluorescein angiography device, characterized in that: The invention comprises an eyepiece, an automatic eye-finding module, an illumination aperture, a rotation speed modulation module, a dichroic mirror, an automatic focus and fixation module, a function switching module, a rotation speed recording module, an imaging lens group and an imaging receiving module. The automatic eye-finding module is symmetrically arranged on both sides of the eyepiece, and the illumination aperture, the dichroic mirror, the function switching module, the imaging lens group and the imaging receiving module coaxially therewith are arranged in sequence from back to front directly in front of the eyepiece. The rotation speed modulation module is arranged on the side of the illumination aperture, and the rotation speed recording module is arranged on the side of the function switching module. The automatic focus and fixation module is reflected by the dichroic mirror and acts on the human eye through the illumination aperture and the eyepiece in sequence.

2. The fundus fluorescein angiography device according to claim 1, characterized in that: The illumination aperture is rotatably arranged at the center of the optical axis, and the rotation speed is controlled by a rotation speed modulation module. A light blocking area and a light passing area are arranged on the illumination aperture. The back of the light blocking area is a conical surface, and an irregular pattern that can reduce light reflection is engraved on the conical surface.

3. The fundus fluorescein angiography device according to claim 2, characterized in that: The irregular pattern capable of reducing light reflection is a matte thread.

4. The fundus fluorescein angiography device according to claim 2, characterized in that: A light absorbing material is sprayed on the irregular pattern of the conical surface.

5. The fundus fluorescein angiography device according to claim 2, characterized in that: The minimum area of ​​the light blocking region of the illumination aperture is the minimum area required to eliminate reflected stray light.

6. The fundus fluorescein angiography device according to claim 1, characterized in that: The function switching module is rotatably arranged at the center of the optical axis, and the rotation speed is recorded in real time by the rotation speed recording module. The function switching module includes an illumination switching component, an illumination filter component, an illumination lamp PCB and an imaging filter component which are arranged in sequence from the back to the front. A through hole is arranged at the center position of the illumination switching component, the illumination filter component and the illumination lamp PCB; A light-blocking area and a light-transmitting area are provided on the lighting switching assembly; N filter areas of equal area are arranged on the illumination filter component, and an illumination filter is arranged on each filter area, and the area of ​​the filter area is adapted to the area of ​​the light-transmitting area on the illumination switching component; The lighting lamp PCB is composed of a plurality of full-spectrum white light LEDs closely arranged on the circuit board, and a side of the lighting lamp PCB on which the full-spectrum white light LEDs are arranged faces the lighting filter component; Functional imaging filters are evenly spaced along the circumference of the imaging filter component. The size of each functional imaging filter is the same as the through hole. The center of the functional imaging filter below is rotated to coincide with the optical axis, and the corresponding functional imaging filter is switched as the position of the lighting switching component changes.

7. The fundus fluorescein angiography device according to claim 1, characterized in that: The imaging receiving module is a planar array photoelectric converter.

8. A method for fundus fluorescein angiography, characterized in that: The fluorescence angiography method is implemented based on the fundus fluorescence angiography device described in any one of claims 1 to 7, and specifically comprises the following steps: Step 1, moving the fundus fluorescein angiography device to a reset position via a three-dimensional platform; Step 2: confirm the function to be run on the fundus fluorescein angiography device, and the internal function switching module of the fundus fluorescein angiography device switches the illumination switching component, the illumination filter component and the imaging filter component to corresponding positions, and keeps the relative positions fixed and rotates along the optical axis; Step 3, start measurement, the automatic eye-finding module moves the fundus fluorescein angiography device to the front of the eye to be measured, and gradually moves it to the working position; Step 4, the auto-focus and fixation modules are turned on to stabilize the visual axis direction of the eye being tested, and the auto-focus makes the image clear; Step 5: If the image is normal, the image is captured normally; if stray light appears in the image, the speed recording module feeds back to the speed modulation module for speed matching adjustment, so that the illumination aperture and the function switching module keep rotating synchronously at the best matching position, and then the image is captured; Step 6: After the acquisition is completed, image analysis is performed and the device returns to the reset position.

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