阅读说明：本技术 共光路光束扫描的大视场自适应光学视网膜成像系统和方法 (Large-field-of-view adaptive optical retina imaging system and method for common-path beam scanning ) 是由 史国华 何益 高峰 孔文 邢利娜 李婉越 张欣 王晶 于 2019-09-09 设计创作，主要内容包括：本发明公开了一种共光路光束扫描的大视场自适应光学视网膜成像系统和方法,该系统包括：光源模块、自适应光学模块、光束扫描模块、离焦补偿模块、视标模块、瞳孔监测模块、探测模块、控制模块和输出模块。本发明提供的系统和方法,可以获取眼底视网膜大视场成像图像、任意感兴趣区域的小视场高分辨率成像图像、以及大视场高分辨率成像图像,并且三类成像图像由共光路结构采集获得,因此三类成像图像特征一致性好,便于进行处理和操作。同时,该系统结构简单,共光路结构可以获取三种类型的视网膜成像图像。多种成像图像通过共光路光束扫描获取,满足不同的应用场景需求,极大地提高了视网膜成像的应用范围。(The invention discloses a common-path light beam scanning large-field-of-view adaptive optical retina imaging system and a common-path light beam scanning large-field-of-view adaptive optical retina imaging method, wherein the system comprises the following steps: the device comprises a light source module, a self-adaptive optical module, a light beam scanning module, a defocusing compensation module, a sighting target module, a pupil monitoring module, a detection module, a control module and an output module. The system and the method provided by the invention can acquire the large-view-field imaging image of the fundus retina, the small-view-field high-resolution imaging image of any interested area and the large-view-field high-resolution imaging image, and the three types of imaging images are acquired by the common optical path structure, so that the three types of imaging images have good characteristic consistency and are convenient to process and operate. Meanwhile, the system is simple in structure, and three types of retina imaging images can be acquired through the common light path structure. Various imaging images are obtained through common-path light beam scanning, the requirements of different application scenes are met, and the application range of retina imaging is greatly enlarged.)

1. A common-path beam-scanning, large-field-of-view, adaptive optical retinal imaging system, comprising: the device comprises a light source module, a self-adaptive optical module, a light beam scanning module, a defocusing compensation module, a sighting target module, a pupil monitoring module, a detection module, a control module and an output module;

the light source module emits parallel light beams, the parallel light beams sequentially pass through the adaptive optics module, the light beam scanning module and the defocusing compensation module and irradiate human eyes, imaging light which is scattered by the human eyes and carries human eye aberration information and light intensity information returns along the original path, and the imaging light is transmitted to the adaptive optics module and the detection module;

the self-adaptive optical module is used for receiving imaging light containing human eye aberration information and realizing real-time measurement and correction of human eye aberration;

the light beam scanning module is controlled by the control module, can be configured into different scanning modes, is used for realizing different scanning imaging functions, and at least comprises: a large field of view imaging function, a small field of view high resolution imaging function and a large field of view high resolution imaging function;

the defocus compensation module is used for realizing compensation of ametropia of the human eyes;

the visual target module is used for guiding and fixing vision of different areas of the retina of the human eye;

the pupil monitoring module is used for realizing the alignment and monitoring of the pupils of human eyes;

the detection module is used for acquiring returned human eye imaging light, converting the human eye imaging light into an electric signal and transmitting the electric signal to the control module;

the output module is connected with the control module and used for displaying and storing the human eye imaging image.

2. The large-field-of-view adaptive optics retinal imaging system with common-path beam scanning according to claim 1, wherein the light source module, the adaptive optics module, the beam scanning module, the sighting target module, the defocus compensation module and the pupil monitoring module are arranged in sequence along an incident light path;

the light source module is configured as a light source, a collimator and a first spectroscope which are sequentially arranged along an incident light path, and outputs parallel light beams to the adaptive optics module; light emitted by the light source partially transmits the first spectroscope through the rear part of the collimator and enters the self-adaptive optical module;

the adaptive optics module is configured as a second spectroscope, a wavefront corrector, a transmission type or reflection type telescope and a wavefront sensor which are sequentially arranged along an incident light path, is connected with the light beam scanning module and is used for realizing wavefront aberration detection and correction; the parallel light beam part output by the light source module transmits the second spectroscope and then is reflected to the transmission type or reflection type telescope by the wavefront corrector and enters the light beam scanning module; the returned imaging light carrying the aberration information and the light intensity information of the human eye is emitted through the light beam scanning module to enter the transmission type or reflection type telescope, and then is reflected to the second spectroscope by the wavefront corrector, part of the imaging light is reflected to the wavefront sensor by the second spectroscope, so that the wavefront aberration measurement is realized, and the rest imaging light is transmitted through the second spectroscope to be continuously transmitted;

the wavefront sensor receives imaging beams containing human eye aberration information and then transmits the imaging beams to the control module for wavefront calculation, wavefront control voltage is obtained and output to the wavefront corrector, and detection and correction of wavefront aberration are achieved.

3. The common-path beam scanning large-field adaptive optics retina imaging system according to claim 2, wherein the detection module is configured to be a collecting lens, a confocal pinhole and a high-sensitivity detector, and a part of the returned imaging light that transmits through the second beam splitter of the adaptive optics module reaches the first beam splitter, and a part of the returned imaging light is reflected by the first beam splitter to the collecting lens, focused, and then reaches the high-sensitivity detector after passing through the confocal pinhole, and is subjected to photoelectric conversion to obtain an electrical signal, and then the electrical signal is output to the control module to be processed to obtain a retina imaging image, and finally the retina imaging image is output to the output module for displaying and storing;

the confocal pinhole is disposed at a focal point of the collection lens.

4. The common-path beam scanning large-field adaptive optics retinal imaging system of claim 3, wherein the beam scanning module is configured as a first scanning mirror and a second scanning mirror, the two scanning mirrors being connected by a transmissive or reflective telescope to achieve pupil surface matching; the first scanning mirror realizes transverse scanning on a retinal plane, the second scanning mirror realizes longitudinal scanning on the retinal plane under the drive of periodic voltage, the second scanning mirror can generate a certain transverse and longitudinal inclination angle under the drive of direct current voltage, and the second scanning mirror can generate the transverse and longitudinal inclination angle under the drive of direct current voltage and can realize transverse and longitudinal two-dimensional scanning on the retinal plane under the drive of periodic voltage;

the front and back positions of the first scanning mirror and the second scanning mirror can be interchanged;

the light beam scanning module is controlled by the output voltage signal of the control module, can be configured into different scanning modes, and realizes different imaging functions, and comprises: a large field of view imaging function, a small field of view high resolution imaging function, and a large field of view high resolution imaging function.

5. The common-path beam scanning large-field-of-view adaptive optics retina imaging system according to claim 2, wherein the defocus compensation module is configured as a scanning objective lens, a flat-field objective lens and a guide rail which are sequentially arranged along an incident light path, an emergent beam of the beam scanning module is transmitted to the pupil monitoring module through the defocus compensation module, and the flat-field objective lens can reciprocate along the central axis of the flat-field objective lens on the guide rail to realize compensation for refractive errors of human eyes.

6. The common-path beam scanning large-field-of-view adaptive optics retina imaging system according to claim 2, wherein the sighting target module is configured as an LED array, a lens and a first dichroic beam splitter, light emitted by any one of the light beads in the LED array after being lighted by the control module is transmitted through the lens and then reflected by the first dichroic beam splitter into the defocus compensation module and finally into the human eye, and the human eye watches the lighted LED light bead to realize fixation; the light beam emitted by the light beam scanning module enters the defocusing compensation module for continuous transmission after being transmitted by the first dichroic beam splitter of the sighting target module;

the pupil monitoring module is configured as an annular LED array, a second dichroic spectroscope, an imaging lens and an area array detector, light emitted by the annular LED array illuminates pupils of human eyes, the pupils of the human eyes penetrate through the hollow part of the annular LED array after being reflected by the pupils of the human eyes, the light is focused to the area array detector by the imaging lens after being totally reflected by the second dichroic spectroscope, the area array detector converts optical signals into electric signals and outputs the electric signals to the control module to obtain pupil imaging images, and the pupil imaging images are finally output to the output module for displaying and storing.

7. The common-path beam-scanning large-field adaptive optics retinal imaging system of claim 4, wherein the control module controls the first and second scanning mirrors in the beam scanning module by outputting voltage signals for implementing different scanning imaging functions;

the implementation method of the large-field-of-view imaging function comprises the following steps:

the self-adaptive optical module is in a power-off state or a power-on non-operating state;

the first scanning mirror is driven by a periodic voltage signal to realize transverse scanning on the plane of the retina; the second scanning mirror is driven by a periodic voltage signal to realize longitudinal scanning on the retina plane. The retina scanning angles of the first scanning mirror and the second scanning mirror driven by the periodic voltage signals are not less than 20 degrees;

the detection module converts the acquired fundus retina optical signals into electric signals, the control module synchronizes periodic driving voltage signals of the first scanning mirror and the second scanning mirror, and the control module samples and reconstructs the electric signals to obtain a retina large-field-of-view imaging image and outputs the retina large-field-of-view imaging image to the output module for displaying and storing.

The method for realizing the small-field high-resolution imaging function comprises the following steps:

the self-adaptive optical module is in a starting working state, so that the measurement and correction of wavefront aberration are realized;

the first scanning mirror is driven by a periodic voltage signal to realize transverse scanning on the plane of the retina; the second scanning mirror can generate certain transverse and longitudinal inclination angles under the drive of a direct-current voltage signal, is used for positioning a light beam for illuminating the fundus retina at an interested position, and then realizes the longitudinal scanning of the retina plane under the drive of a periodic voltage signal; the retina scanning angles of the first scanning mirror and the second scanning mirror under the drive of the periodic voltage signals are not more than 5 degrees;

the direct current voltage signal is obtained by calculation of the control module according to the coordinate position of the eye fundus retina;

the detection module converts the acquired fundus retina optical signals into electric signals, the control module synchronizes periodic driving voltage signals of the first scanning mirror and the second scanning mirror, the control module samples and reconstructs the electric signals to obtain a retina small visual field high-resolution imaging image, and meanwhile, the fundus retina coordinate position is marked in the imaging image; and the small-field high-resolution imaging image is output to the output module through the control module to be displayed and stored.

The implementation method of the large-field-of-view high-resolution imaging function comprises the following steps:

the self-adaptive optical module is in a starting working state, so that the measurement and correction of wavefront aberration are realized;

the first scanning mirror is driven by a periodic voltage signal to realize transverse scanning on the plane of the retina; the second scanning mirror is driven by a periodic voltage signal to realize longitudinal scanning on the plane of the retina; the retina scanning angles of the first scanning mirror and the second scanning mirror under the drive of the periodic voltage signals are not more than 5 degrees;

at the moment, the second scanning mirror can generate certain transverse and longitudinal inclination angles under the drive of a direct-current voltage signal, light beams are sequentially inclined to illuminate each area of the fundus retina, the single transverse and longitudinal inclination angle of the second scanning mirror is not more than 3 degrees, and the maximum transverse and longitudinal inclination angle of the retina under the drive of the direct-current voltage signal of the second scanning mirror is not more than 15 degrees; the direct current voltage signal is obtained by calculation of the control module according to the coordinate position of the eye fundus retina;

when each area of the fundus retina is sequentially illuminated by the light beams, the control module can obtain high-resolution imaging images of each area of the retina, and the control module splices the images according to the position coordinates of the fundus retina of the high-resolution imaging images of each area to obtain a large-field high-resolution image of the fundus retina, and then outputs the large-field high-resolution image to the output module for displaying and storing.

8. The co-path beam scanning large field of view adaptive optics retinal imaging system of claim 7, wherein the light source module may include a plurality of light sources that may be coupled into a collimator through a fiber coupler to be collimated into a parallel beam; the plurality of light sources can also be collimated into parallel beams by respective collimators and then coupled into a light path by the dichroic beam splitter;

the collimator can be a single lens, an achromatic lens, a apochromatic lens or a parabolic reflector and is used for collimating the light beams emitted by the light source into parallel light beams;

the first spectroscope is a broadband spectroscope, 20% of parallel light beams emitted by the collimator continuously transmit through the spectroscope and enter the adaptive optical module, and 80% of emergent imaging light beams returned by the adaptive optical module are reflected by the first spectroscope and enter the detection module.

9. The common-path beam scanning large-field-of-view adaptive optics retinal imaging system of claim 2, wherein the adaptive optics module comprises the wavefront sensor that is one of a microprism array hartmann wavefront sensor, a microlens array hartmann wavefront sensor, a rectangular pyramid sensor, and a curvature sensor, and the wavefront corrector is one of a deformable mirror, a liquid crystal spatial light modulator, a micro-machined thin film deformable mirror, a micro-electromechanical deformable mirror, a bimorph ceramic deformable mirror, and a liquid deformable mirror.

95% of parallel light beams output by the light source module are transmitted to the wavefront corrector through the second spectroscope; the returned imaging light beam is reflected to the second spectroscope for light splitting through the wavefront corrector, wherein 5% of light energy is reflected to enter the wavefront sensor to realize wavefront aberration measurement; the rest 95% of the light energy is transmitted to the first beam splitter to continue to propagate.

10. A method of large field of view adaptive optics retinal imaging with common path beam scanning using the system of any one of claims 1-9, comprising the steps of:

step S1: starting up the system;

step S2: the head of the tested person is placed on the head support frame, the pupil monitoring module is started, and the three-dimensional translation of the head support frame is automatically adjusted through the manual adjustment or control module, so that the pupil is imaged in the middle area of the visual field;

step S3: the flat field objective lens is manually slid to move along the center of the optical axis, or the position of the flat field objective lens on the guide rail is moved through a control module driving motor, so that the compensation and correction of the ametropia of the human eye are realized;

step S4: lightening a lamp bead in an LED array in the sighting target module, and watching the light spot by a subject to realize fixation;

step S5: the self-adaptive optical module is in a shutdown or startup non-operating state, the light beam scanning module is set to be in a large visual field scanning mode, and the control module controls the light beam scanning module to complete large visual field scanning, so that retina large visual field imaging is realized and output to the output module;

step S6: the self-adaptive optical module is started to work and is used for realizing wavefront aberration measurement and correction, and the control module controls the light beam scanning module to carry out small-field scanning, wherein the small-field scanning comprises two small-field scanning modes S61 and S62;

step S61: the control module controls the light beam scanning module to complete outputting of the small-field high-resolution imaging image to the output module 10;

step S62: the control module controls the light beam scanning module to complete a large-view-field high-resolution imaging image and output the large-view-field high-resolution imaging image to the output module.

The sequence of the step S5 and the sequence of the step S6 can be exchanged, and the step S61 and the step S62 have no sequence relation and are selected according to requirements.

Technical Field

The invention relates to the technical field of optical imaging, in particular to a common-path light beam scanning large-field-of-view adaptive optical retina imaging system and method.

Background

The traditional confocal scanning technology is developed into a mature laser confocal scanning imaging device (Webb R, Hughes G, Delori F. structural scanning laser applied optics, 1987; 26 (8): 1492-9) in 1987, and is widely applied to retina imaging, and can realize fundus retina living body imaging with a large visual field. However, the eyeball is a complex optical system, optical aberration inevitably exists even in the non-ametropia eye, especially in order to obtain a high-resolution image under a large numerical aperture, a higher resolution of a diffraction limit can be obtained under a large pupil according to an optical theory, but the actual resolution is greatly limited by more eye aberration brought by the large pupil, and a traditional laser confocal scanning ophthalmoscope can generally obtain a large field imaging image of the fundus above 10 degrees, but is difficult to distinguish blood vessels below 20 microns, and cannot observe fine structures such as visual cells.

In the nineteenth century, with the introduction of adaptive optics technology into fundus retinal imaging, correction devices such as adaptive optics deformable mirrors can be used for well correcting human eye aberrations, so that high resolution of diffraction limit is obtained, and living observation of retinal microvasculature and visual cells is realized for the first time. The patent No. ZL201010197028.0 proposes a retinal imaging device based on adaptive optics technology, which realizes two-dimensional synchronous scanning of retinal planes through two independent scanning galvanometers, so as to realize confocal scanning imaging and high-resolution imaging. However, this device can only achieve high resolution imaging of the human eye with a maximum field of view of 3 degrees. Limited by an adaptive optics aberration correction isoplanatic zone, adaptive optics usually make a compromise on an imaging field of view while realizing high-resolution imaging, and can only realize small-field imaging within 3 degrees.

From the above, the existing laser confocal scanning ophthalmoscope has a large imaging field of view, but the resolution is not enough to observe the retina microstructure; the laser confocal scanning ophthalmoscope combined with the adaptive optics can observe the retina microstructure, but the imaging field of view is small, and the focus condition of a larger field of view cannot be observed.

Disclosure of Invention

The technical problem to be solved by the present invention is to provide a common optical path beam scanning large-field-of-view adaptive optical retinal imaging system, aiming at the defects in the prior art.

As is known, the existing laser confocal scanning ophthalmoscope has a large imaging field of view, but the resolution is not enough to observe the retina microstructure; the laser confocal scanning ophthalmoscope combined with the adaptive optics can observe the retina microstructure, but the imaging field of view is small, and the focus condition of a larger field of view cannot be observed.

Compared with the technical achievements in the laser confocal scanning imaging field at home and abroad, the invention provides a large-field-of-view adaptive optical retina imaging system for light beam scanning in a common light path on the basis of the basic principle of combining adaptive optics with a confocal scanning technology, adopts a common light path structure of two scanning mirrors, and configures the two scanning mirrors into different scanning modes, so that large-field-of-view imaging exceeding 20 degrees can be completed on a retina for observing a focus area of a retinal disease; the system can also complete small-field scanning imaging of less than 5 degrees on the retina, realize small-field high-resolution imaging observation of lesion microstructure and pathological change under the condition of self-adaptive optical correction of aberration, further arrange a second scanning mirror to realize sequential oblique illumination of light beams in each area of the retina, and then can acquire large-field high-resolution imaging of more than 15 degrees on the retina at one time through image splicing.

The technical scheme adopted by the invention is as follows: a common-path beam-scanning large-field-of-view adaptive optics retinal imaging system, comprising: the device comprises a light source module, a self-adaptive optical module, a light beam scanning module, a defocusing compensation module, a sighting target module, a pupil monitoring module, a detection module, a control module and an output module;

the light source module emits parallel light beams, the parallel light beams sequentially pass through the adaptive optics module, the light beam scanning module and the defocusing compensation module and irradiate human eyes, imaging light which is scattered by the human eyes and carries human eye aberration information and light intensity information returns along the original path, and the imaging light is transmitted to the adaptive optics module and the detection module;

the self-adaptive optical module is used for receiving imaging light containing human eye aberration information and realizing real-time measurement and correction of human eye aberration;

the light beam scanning module is controlled by the control module, can be configured into different scanning modes, is used for realizing different scanning imaging functions, and at least comprises: a large field of view imaging function, a small field of view high resolution imaging function and a large field of view high resolution imaging function;

the defocus compensation module is used for realizing compensation of ametropia of the human eyes;

the visual target module is used for guiding and fixing vision of different areas of the retina of the human eye;

the pupil monitoring module is used for realizing the alignment and monitoring of the pupils of human eyes;

the detection module is used for acquiring returned human eye imaging light, converting the human eye imaging light into an electric signal and transmitting the electric signal to the control module;

the output module is connected with the control module and used for displaying and storing the human eye imaging image.

Preferably, the light source module, the adaptive optics module, the light beam scanning module, the sighting target module, the defocusing compensation module and the pupil monitoring module are sequentially arranged along an incident light path;

the light source module is configured as a light source, a collimator and a first spectroscope which are sequentially arranged along an incident light path, and outputs parallel light beams to the adaptive optics module; light emitted by the light source partially transmits the first spectroscope through the rear part of the collimator and enters the self-adaptive optical module;

the adaptive optics module is configured as a second spectroscope, a wavefront corrector, a transmission type or reflection type telescope and a wavefront sensor which are sequentially arranged along an incident light path, is connected with the light beam scanning module and is used for realizing wavefront aberration detection and correction; the parallel light beam part output by the light source module transmits the second spectroscope and then is reflected to the transmission type or reflection type telescope by the wavefront corrector and enters the light beam scanning module; the returned imaging light carrying the aberration information and the light intensity information of the human eye is emitted through the light beam scanning module to enter the transmission type or reflection type telescope, and then is reflected to the second spectroscope by the wavefront corrector, part of the imaging light is reflected to the wavefront sensor by the second spectroscope, so that the wavefront aberration measurement is realized, and the rest imaging light is transmitted through the second spectroscope to be continuously transmitted;

the wavefront sensor receives imaging beams containing human eye aberration information and then transmits the imaging beams to the control module for wavefront calculation, wavefront control voltage is obtained and output to the wavefront corrector, and detection and correction of wavefront aberration are achieved.

Preferably, the detection module is configured to be a collecting lens, a confocal pinhole, and a high-sensitivity detector, a part of the returned imaging light that transmits through the second beam splitter of the adaptive optics module reaches the first beam splitter, and a part of the returned imaging light is reflected by the first beam splitter to the collecting lens, focused through the confocal pinhole and reaches the high-sensitivity detector, and subjected to photoelectric conversion to obtain an electrical signal, and then output to the control module for processing to obtain a retina imaging image, and finally output to the output module for displaying and storing;

the confocal pinhole is disposed at a focal point of the collection lens.

Preferably, the light beam scanning module is configured as a first scanning mirror and a second scanning mirror, and the two scanning mirrors are connected through a transmission type or reflection type telescope to realize pupil surface matching; the first scanning mirror realizes transverse scanning on a retinal plane, the second scanning mirror realizes longitudinal scanning on the retinal plane under the drive of periodic voltage, the second scanning mirror can generate a certain transverse and longitudinal inclination angle under the drive of direct current voltage, and the second scanning mirror can generate the transverse and longitudinal inclination angle under the drive of direct current voltage and can realize transverse and longitudinal two-dimensional scanning on the retinal plane under the drive of periodic voltage;

the front and back positions of the first scanning mirror and the second scanning mirror can be interchanged;

the light beam scanning module is controlled by the output voltage signal of the control module, can be configured into different scanning modes, and realizes different imaging functions, and comprises: a large field of view imaging function, a small field of view high resolution imaging function, and a large field of view high resolution imaging function.

Preferably, the defocus compensation module is configured to be a scanning objective lens, a field flattener objective lens and a guide rail which are sequentially arranged along an incident light path, an emergent light beam of the light beam scanning module is transmitted to the pupil monitoring module through the defocus compensation module, and the field flattener objective lens can reciprocate on the guide rail along the central axis of the field flattener objective lens to realize the compensation of the ametropia of the human eye.

Preferably, the sighting target module is configured as an LED array, a lens and a first dichroic beam splitter, light emitted by any one of the lamp beads in the LED array after being lighted by the control module is transmitted through the lens and then reflected by the first dichroic beam splitter to enter the defocus compensation module and finally enter human eyes, and the human eyes watch the luminous LED lamp beads to realize fixation; the light beam emitted by the light beam scanning module enters the defocusing compensation module for continuous transmission after being transmitted by the first dichroic beam splitter of the sighting target module.

The pupil monitoring module is configured as an annular LED array, a second dichroic spectroscope, an imaging lens and an area array detector, light emitted by the annular LED array illuminates pupils of human eyes, the pupils of the human eyes penetrate through the hollow part of the annular LED array after being reflected by the pupils of the human eyes, the light is focused to the area array detector by the imaging lens after being totally reflected by the second dichroic spectroscope, the area array detector converts optical signals into electric signals and outputs the electric signals to the control module to obtain pupil imaging images, and the pupil imaging images are finally output to the output module for displaying and storing.

Preferably, the control module controls the first scanning mirror and the second scanning mirror in the light beam scanning module through output voltage signals, so as to realize different scanning imaging functions;

the implementation method of the large-field-of-view imaging function comprises the following steps:

the self-adaptive optical module is in a power-off state or a power-on non-operating state;

the first scanning mirror is driven by a periodic voltage signal to realize transverse scanning on the plane of the retina; the second scanning mirror is driven by a periodic voltage signal to realize longitudinal scanning on the retina plane. The retina scanning angles of the first scanning mirror and the second scanning mirror driven by the periodic voltage signals are not less than 20 degrees;

the detection module converts the acquired fundus retina optical signals into electric signals, the control module synchronizes periodic driving voltage signals of the first scanning mirror and the second scanning mirror, and the control module samples and reconstructs the electric signals to obtain a retina large-field-of-view imaging image and outputs the retina large-field-of-view imaging image to the output module for displaying and storing;

the method for realizing the small-field high-resolution imaging function comprises the following steps:

the self-adaptive optical module is in a starting working state, so that the measurement and correction of wavefront aberration are realized;

the first scanning mirror is driven by a periodic voltage signal to realize transverse scanning on the plane of the retina; the second scanning mirror can generate certain transverse and longitudinal inclination angles under the drive of a direct-current voltage signal, is used for positioning a light beam for illuminating the fundus retina at an interested position, and then realizes the longitudinal scanning of the retina plane under the drive of a periodic voltage signal; the retina scanning angles of the first scanning mirror and the second scanning mirror under the drive of the periodic voltage signals are not more than 5 degrees;

the direct current voltage signal is obtained by calculation of the control module according to the coordinate position of the eye fundus retina;

the detection module converts the acquired fundus retina optical signals into electric signals, the control module synchronizes periodic driving voltage signals of the first scanning mirror and the second scanning mirror, the control module samples and reconstructs the electric signals to obtain a retina small visual field high-resolution imaging image, and meanwhile, the fundus retina coordinate position is marked in the imaging image; the small-field-of-view high-resolution imaging image is output to the output module through the control module to be displayed and stored;

the implementation method of the large-field-of-view high-resolution imaging function comprises the following steps:

the self-adaptive optical module is in a starting working state, so that the measurement and correction of wavefront aberration are realized;

the first scanning mirror is driven by a periodic voltage signal to realize transverse scanning on the plane of the retina; the second scanning mirror is driven by a periodic voltage signal to realize longitudinal scanning on the plane of the retina; the retina scanning angles of the first scanning mirror and the second scanning mirror under the drive of the periodic voltage signals are not more than 5 degrees;

at the moment, the second scanning mirror can generate certain transverse and longitudinal inclination angles under the drive of a direct-current voltage signal, light beams are sequentially inclined to illuminate each area of the fundus retina, the single transverse and longitudinal inclination angle of the second scanning mirror is not more than 3 degrees, and the maximum transverse and longitudinal inclination angle of the retina under the drive of the direct-current voltage signal of the second scanning mirror is not more than 15 degrees; the direct current voltage signal is obtained by calculation of the control module according to the coordinate position of the eye fundus retina;

when each area of the fundus retina is sequentially illuminated by the light beams, the control module can obtain high-resolution imaging images of each area of the retina, and the control module splices the images according to the position coordinates of the fundus retina of the high-resolution imaging images of each area to obtain a large-field high-resolution image of the fundus retina, and then outputs the large-field high-resolution image to the output module for displaying and storing.

Preferably, the light source module may include a plurality of light sources, which may be coupled into the collimator through a fiber coupler to be collimated into parallel beams; the plurality of light sources can also be collimated into parallel beams by respective collimators and then coupled into a light path by the dichroic beam splitter;

the collimator can be a single lens, an achromatic lens, a apochromatic lens or a parabolic reflector and is used for collimating the light beams emitted by the light source into parallel light beams;

the first spectroscope is a broadband spectroscope, 20% of parallel light beams emitted by the collimator continuously transmit through the spectroscope and enter the adaptive optical module, and 80% of emergent imaging light beams returned by the adaptive optical module are reflected by the first spectroscope and enter the detection module.

Preferably, the wavefront sensor included in the adaptive optics module is one of a microprism array hartmann wavefront sensor, a microlens array hartmann wavefront sensor, a rectangular pyramid sensor and a curvature sensor, and the wavefront corrector is one of a deformable mirror, a liquid crystal spatial light modulator, a micro-machined thin film deformable mirror, a micro-electromechanical deformable mirror, a double piezoelectric ceramic deformable mirror and a liquid deformable mirror.

95% of parallel light beams output by the light source module are transmitted to the wavefront corrector through the second spectroscope; the returned imaging light beam is reflected to the second spectroscope for light splitting through the wavefront corrector, wherein 5% of light energy is reflected to enter the wavefront sensor to realize wavefront aberration measurement; the rest 95% of the light energy is transmitted to the first beam splitter to continue to propagate.

A method of large field of view adaptive optics retinal imaging with common path beam scanning using a system as described above, comprising the steps of:

step S1: starting up the system;

step S2: the head of the tested person is placed on the head support frame, the pupil monitoring module is started, and the three-dimensional translation of the head support frame is automatically adjusted through the manual adjustment or control module, so that the pupil is imaged in the middle area of the visual field;

step S3: the flat field objective lens is manually slid to move along the center of the optical axis, or the position of the flat field objective lens on the guide rail is moved through a control module driving motor, so that the compensation and correction of the ametropia of the human eye are realized;

step S4: lighting a lamp bead in the LED array, and watching the light spot by a subject to realize fixation;

step S5: the self-adaptive optical module is in a shutdown or startup non-operating state, the light beam scanning module is set to be in a large visual field scanning mode, and the control module controls the light beam scanning module to complete large visual field scanning, so that retina large visual field imaging is realized and output to the output module;

step S6: the self-adaptive optical module is started to work and is used for realizing wavefront aberration measurement and correction, and the control module controls the light beam scanning module to carry out small-field scanning, wherein the control module can comprise two small-field scanning modes S61 and S62;

step S61: the control module controls the light beam scanning module to complete outputting of the small-field high-resolution imaging image to the output module 10;

step S62: the control module controls the light beam scanning module to complete a large-view-field high-resolution imaging image and output the large-view-field high-resolution imaging image to the output module.

Wherein, the sequence of step S5 and step S6 can be reversed. The step S61 and the step S62 have no sequence relationship and can be selected according to requirements.

The invention has the beneficial effects that:

the invention provides a large-field-of-view adaptive optical retina imaging system and method for common-path light beam scanning. By controlling the two scanning mirrors to be in different scanning modes, different scanning imaging functions can be realized, including a large-field scanning imaging function, and a retina large-field imaging image can be obtained; the small-view-field high-resolution imaging function can realize small-view-field high-resolution imaging observation on any interested position of the retina; and the large-view-field high-resolution imaging function is used for splicing the images according to the fundus retina position coordinates of the high-resolution imaging images in the areas, so that the large-view-field high-resolution imaging images of the fundus retina can be obtained.

The large-view-field adaptive optical retina imaging system and method based on common-path beam scanning can acquire large-view-field imaging images of fundus retina, small-view-field high-resolution imaging images of any interested area and large-view-field high-resolution imaging images, and the three types of imaging images are acquired by a common-path structure, so that the three types of imaging images have good feature consistency and are convenient to process and operate. Meanwhile, the system is simple in structure, and three types of retina imaging images can be acquired through the common light path structure: by switching different synchronous scanning modes, the retina disease focus area can be observed through large-view-field imaging, and the focus microstructure can also be observed through small-view-field high-resolution imaging. The large-field imaging image can observe the characteristics of structures, focuses and the like of the retina in a large range, the small-field high-resolution imaging image can observe the fine structure of any interested region, and the large-field high-resolution imaging image can observe the fine structure of the retina in the large range. Various imaging images are obtained through common-path light beam scanning, the requirements of different application scenes are met, and the application range of retina imaging is greatly enlarged.

Drawings

FIG. 1 is a functional block diagram of a common path beam scanning large field of view adaptive optics retinal imaging system of the present invention;

FIG. 2 is a schematic diagram of the optical path structure of the common-path beam scanning large-field-of-view adaptive optics retinal imaging system of the present invention;

FIG. 3 is a schematic workflow diagram of a common path beam scanning large field of view adaptive optics retinal imaging system of the present invention;

description of reference numerals:

1-a light source module; 2-adaptive optics module; 3-a beam scanning module; 4-defocus compensation module; 5-human eye; 6-visual target module; 7-pupil monitoring module; 8, a detection module; 9-a control module; 10-an output module; 101-a light source; 102-a collimator; 103-a first beam splitter; 201-a second beam splitter; 202-wavefront corrector; 203-transmission telescope or reflection telescope; 204 — wavefront sensor; 301 — a first scan mirror; 302-transmission telescope or reflection telescope; 303 — a second scanning mirror; 401-scanning objective lens; 402-field flattening objective; 403-guide rails; 601 — an LED array; 602-a lens; 603 — a first dichroic beamsplitter; 701-annular LED array; 702 — a second dichroic beamsplitter; 703-an imaging lens; 704-area array detector; 801-collecting lens; 802-confocal pinhole; 803 — high sensitivity detector.

Detailed Description

The present invention is further described in detail below with reference to examples so that those skilled in the art can practice the invention with reference to the description.

It will be understood that terms such as "having," "including," and "comprising," as used herein, do not preclude the presence or addition of one or more other elements or groups thereof.

As shown in fig. 1-2, a common-path beam scanning large-field adaptive optical retinal imaging system of the present embodiment includes: the system comprises a light source module 1, an adaptive optics module 2, a light beam scanning module 3, a defocusing compensation module 4, a sighting target module 6, a pupil monitoring module 7, a detection module 8, a control module 9 and an output module 10;

the light source module 1 emits parallel light beams, the parallel light beams sequentially pass through the adaptive optics module 2, the light beam scanning module 3 and the defocusing compensation module 4 to irradiate human eyes 5, imaging light which is scattered by the human eyes 5 and carries human eye aberration information and light intensity information returns along the original path, and the imaging light is transmitted to the adaptive optics module 2 and the detection module 8;

the adaptive optics module 2 is used for receiving imaging light containing human eye aberration information and realizing real-time measurement and correction of human eye aberration;

the beam scanning module 3 is controlled by the control module 9, and can be configured to different scanning modes for implementing different scanning imaging functions, and includes at least: a large field of view imaging function, a small field of view high resolution imaging function and a large field of view high resolution imaging function;

the defocus compensation module 4 is used for realizing compensation of refractive errors of the human eyes;

the visual target module 6 is used for realizing the guidance and fixation of different areas of the retina of the human eye;

the pupil monitoring module 7 is used for realizing the alignment and monitoring of the pupils of human eyes;

the detection module 8 is used for acquiring returned human eye imaging light, converting the human eye imaging light into an electric signal and transmitting the electric signal to the control module 9;

the output module 10 is connected with the control module 9 and is used for displaying and storing human eye imaging images (fundus retina imaging images and pupil imaging images).

The system comprises a light source module 1, an adaptive optics module 2, a light beam scanning module 3, a sighting target module 6, a defocusing compensation module 4 and a pupil monitoring module 7, wherein the light source module, the adaptive optics module 2, the light beam scanning module 3, the sighting target module 6, the defocusing compensation module 4 and the pupil monitoring module 7 are sequentially arranged along an incident light path; the light source module 1 is configured as a light source 101, a collimator 102 and a first spectroscope 103 which are sequentially arranged along an incident light path and outputs parallel light beams to the adaptive optics module 2; light emitted by the light source 101 partially transmits the first beam splitter 103 through the rear part of the collimator 102, and enters the adaptive optics module 2.

The light source module 1 may include a plurality of light sources 101, the plurality of light sources 101 may be coupled into a collimator 102 through a fiber coupler to be collimated into parallel beams; the plurality of light sources 101 can also be collimated into parallel beams by the respective collimators 102 and then coupled into the light path by the dichroic beam splitter; the plurality of light sources 101 may include typical fundus imaging illumination wavelengths, such as characteristic wavelengths of 488nm, 515nm, 650nm, 680nm, 780nm, 830nm, and the like.

The collimator 102 may be a single lens, an achromatic lens, a apochromatic lens or a parabolic mirror, and is used for collimating the light beam emitted from the light source 101 into a parallel light beam. In this embodiment, the reflective collimator 102RC12FC-P01 from thorlabs is selected.

In this embodiment, the first beam splitter 103 is a broadband beam splitter with a 20:80 transmittance-reflectance ratio. 20% of the parallel light beams emitted from the collimator 102 continuously propagate through the first beam splitter 103 and enter the adaptive optics module 2, and 80% of the imaging light beams returned from the adaptive optics module 2 and enter the detection module 8 after being reflected by the first beam splitter 103.

First dichroic beamsplitter 603 is transmissive to all wavelengths contained by light source 101 and second dichroic beamsplitter 702 is transmissive to all wavelengths contained by light source 101.

The adaptive optics module 2 is configured to be a second beam splitter 201, a wavefront corrector 202, a transmission type or reflection type telescope 203 and a wavefront sensor 204 which are sequentially arranged along an incident light path, connected with the light beam scanning module 3, and used for realizing detection and correction of wavefront aberration; the parallel light beam part output by the light source module 1 is transmitted by the second beam splitter 201, then reflected to the transmission type or reflection type telescope 203 by the wavefront corrector 202, and enters the light beam scanning module 3; the returned imaging light carrying the aberration information and the light intensity information of the human eye is emitted through the light beam scanning module 3 to enter the transmission type or reflection type telescope 203, and then is reflected to the second spectroscope 201 by the wavefront corrector 202, part of the imaging light is reflected to the wavefront sensor 204 by the second spectroscope 201, so that the wavefront aberration measurement is realized, and the rest imaging light is transmitted through the second spectroscope 201 to continue to be transmitted;

the wavefront aberration detected by the wavefront sensor 204 is processed by the control module 9 to obtain a wavefront control voltage and output the wavefront control voltage to the wavefront corrector 202, so that the wavefront aberration is corrected.

The wavefront sensor 204 included in the adaptive optics module 2 is one of a microprism array hartmann wavefront sensor, a microlens array hartmann wavefront sensor, a rectangular pyramid sensor and a curvature sensor, and the wavefront corrector 202 is one of a deformable mirror, a liquid crystal spatial light modulator, a micro-machined thin film deformable mirror, a micro-electromechanical deformable mirror, a double piezoelectric ceramic deformable mirror and a liquid deformable mirror.

In this embodiment, the second beam splitter 201 is a broadband beam splitter with a transmission reflectance of 95: 5. 95% of the parallel light beams output by the light source module 1 are transmitted to the wavefront corrector 202 through the second beam splitter 201; the returned imaging light beam is reflected to a second spectroscope 201 through a wavefront corrector 202 for light splitting, wherein 5% of light energy is reflected to enter a wavefront sensor 204, and wavefront aberration measurement is realized; the remaining 95% of the light energy is transmitted to the first beam splitter 103 to continue propagating.

The detection module 8 is configured to be a collecting lens 801, a confocal pinhole 802 and a high-sensitivity detector 803, the returned imaging light beam is transmitted through the second beam splitter 201 of the adaptive optics module 2, reaches the first beam splitter 103, is reflected to the collecting lens 801 by the first beam splitter 103, is focused through the confocal pinhole 802, reaches the high-sensitivity detector 803, is subjected to photoelectric conversion to obtain an electric signal, is output to the control module 9 for processing to obtain a retina imaging image, and is finally output to the output module 10 for displaying and storing; a confocal pinhole 802 is disposed at the focus of the collection lens 801.

The collection lens 801 may be an achromatic lens, or apochromatic lens, or a combination of lenses, having a focal length of no less than 100 mm. In a preferred embodiment, the confocal pinhole 802 is 50 microns, which is replaceable in size according to optical energy efficiency, not exceeding 200 microns. The high sensitivity detector 803 may be a photomultiplier tube, or an avalanche diode.

The light beam scanning module 3 is configured as a first scanning mirror 301 and a second scanning mirror 303, and the two scanning mirrors are connected through a transmission telescope or a reflection telescope 302 to realize pupil surface matching; the first scanning mirror 301 realizes transverse scanning on a retinal plane, the second scanning mirror 303 realizes longitudinal scanning on the retinal plane under the drive of periodic voltage, the second scanning mirror 303 can generate a certain transverse and longitudinal inclination angle under the drive of direct current voltage, and the second scanning mirror 303 can generate the transverse and longitudinal inclination angle under the drive of direct current voltage and can realize transverse and longitudinal two-dimensional scanning on the retinal plane under the drive of periodic voltage;

the front and back positions of the first scanning mirror 301 and the second scanning mirror 303 can be interchanged, and the imaging effect is not influenced;

the light beam scanning module 3 is controlled by the output voltage signal of the control module 9, and can be configured into different scanning modes to realize different imaging functions, including: a large field of view imaging function, a small field of view high resolution imaging function, and a large field of view high resolution imaging function.

In this embodiment, the first scanning mirror 301 is a resonant galvanometer 6SC08KA040-02Y manufactured by Cambridge, and the second scanning mirror 303 is a fast mirror MR-30-15-G-25X 25D manufactured by Optoture.

The defocus compensation module 4 is configured to be a scanning objective lens 401, a flat field objective lens 402 and a guide rail 403 which are sequentially arranged along an incident light path, an emergent light beam of the light beam scanning module 3 is transmitted to the pupil monitoring module 7 through the defocus compensation module 4, and the flat field objective lens 402 can reciprocate along the central axis of the flat field objective lens 402 on the guide rail 403 to realize the compensation of the refractive error of the human eye.

The extending direction of the guide rail 403 coincides with the central axis direction of the field flattener objective lens 402, and the field flattener objective lens 402 is slidably disposed on the guide rail 403.

In a preferred embodiment, the field flattener objective 402 is connected to the guide rail 403 through a motor, and the control module 9 can control the field flattener objective 402 to reciprocate along the central axis thereof, so as to compensate for the ametropia of the human eye. More preferably, the scanning objective lens 401 is an achromatic lens, an apochromatic lens, an aspheric lens, or a combination of lenses, the field angle is greater than 30 degrees, and the field flattener objective lens 402 may be an achromatic lens, an apochromatic lens, an aspheric lens, or a combination of lenses, and performs a field flattener effect on the fundus retina.

The sighting target module 6 is configured to an LED array 601, a lens 602 and a first dichroic beam splitter 603, light emitted by any one of the lamp beads in the LED array 601 after being lighted by the control module 9 is transmitted by the lens 602, reflected by the first dichroic beam splitter 603, enters the defocus compensation module 4 and finally enters the human eye 5, and the human eye 5 watches the light-emitting LED lamp bead to realize fixation; the light beam emitted from the light beam scanning module 3 is transmitted by the first dichroic beam splitter 603 of the sighting target module 6, and then enters the defocus compensation module 4 to continue propagating.

The LED lamp beads of the LED array 601 select a certain characteristic wavelength within the range of 500nm-600nm, the wavelength selected by the LED array 601 is different from the wavelength contained in the light source 101, and the wavelength difference needs to be more than 30nm, so that the first dichroic beam splitter 603 has a reflection function on the wavelength selected by the LED array 601, and has a transmission function on the wavelength selected by the light source 101. By the control module 9 lighting up the lamp beads at different positions on the LED array 601, different areas of the fundus retina will be guided to be imaging areas.

The pupil monitoring module 7 is configured to be an annular LED array 701, a second dichroic beam splitter 702, an imaging lens 703 and an area array detector 704, light emitted by the annular LED array 701 illuminates pupils of the human eyes 5, the light passes through a hollow part of the annular LED array 701 after being reflected by the pupils of the human eyes 5, the light is focused to the area array detector 704 by the imaging lens 703 after being totally reflected by the second dichroic beam splitter 702, the area array detector 704 converts an optical signal into an electrical signal and outputs the electrical signal to the control module 9 to obtain a pupil imaging image, and the pupil imaging image is finally output to the output module 10 for displaying and storing.

The LED lamp beads of the annular LED array 701 can select near-infrared wavelengths of 900nm or above, and the second dichroic beam splitter 702 reflects the emergent wavelengths of the lamp beads of the annular LED array 701.

There are several processes in the operation of the imaging system including a main light path transmission process, a subject correlation process, an adaptive optical aberration measurement and correction process, and a scanning imaging process.

1. Optical path transmission process

The transmission light path is as follows: the light emitted by the light source 101 can be approximately regarded as a point light source 101, is collimated into parallel light beams by the collimator 102, and is split by the first beam splitter 103, and 20% of the light energy is transmitted into the second beam splitter 201 for splitting; in the incident light reaching the second beam splitter 201, 95% of the light energy is reflected by the wavefront corrector 202 after being transmitted, the parallel light beams continue to pass through the transmission type or reflection type telescope 203 to realize pupil aperture matching, are reflected by the first scanning mirror 301, realize pupil aperture matching through the transmission type or reflection type telescope 302, reach the second scanning mirror 303 to be reflected, are transmitted by the first dichroic beam splitter 603, then sequentially pass through the scanning objective 401 and the flat field objective 402 to be transmitted, then pass through the hollow part of the annular LED array 701 after being transmitted by the second dichroic beam splitter 702 to reach the human eye 5, and focus the light beams to one point on the retina through the optical system of the human eye 5;

the eyeground of the human eye has a scattering effect on the incident light, the scattered imaging light carries aberration information of the human eye and light intensity information of the eyeground at the point, the imaging light returns to the second spectroscope 201 along the original path, and the second spectroscope 201 splits the scattered light again: 5% of the light energy is reflected into the wavefront sensor 204; the remaining 95% of the light energy propagates through transmission to the first beam splitter 103. The first spectroscope 103 reflects 80% of the light energy into the collecting lens 801, and the light energy reaches the high-sensitivity detector 803 after passing through the confocal pinhole 802, and the high-sensitivity detector 803 performs photoelectric conversion to obtain an electric signal, and then outputs the electric signal to the control module 9 for processing to obtain a retina imaging image, and finally outputs the retina imaging image to the output module 10 for displaying and storing.

2. The subject-related procedures mainly include pupil alignment and monitoring, ametropia compensation and correction, visual target guidance and fixation.

(1) Pupil alignment and monitoring

The pupil monitoring module 7 includes an annular LED array 701, a second dichroic beam splitter 702, an imaging lens 703 and an area array detector 704, the annular LED array 701 includes at least three LED beads, the LED beads are arranged in an annular shape at equal intervals, the aperture of the hollow part is not smaller than the aperture of the imaging light beam, the emergent light of the annular LED array 701 reaches the pupil of the human eye 5, the light beam reflected by the pupil of the human eye 5 passes through the hollow part of the annular LED array 701, is reflected by the second dichroic beam splitter 702 and then focused on the area array detector 704 through the imaging lens 703, the area array detector 704 converts the optical signal into an electrical signal, the electrical signal is output to the control module 9 to obtain a pupil imaging image, and the optical signal is output to the output module 10 to realize functions of displaying, storing, processing and.

When the system works, the head of a subject is positioned on the head support frame, the head support frame has a three-dimensional translation adjusting function, the three-dimensional translation guide rail of the head support frame can be manually adjusted, the three-dimensional translation guide rail can also be configured to be a three-dimensional translation guide rail of the motor driven head support frame, and the motor is driven by the control module 9 to realize automatic adjustment, so that pupils are imaged in the middle area of a visual field.

(2) Ametropia compensation and correction

The defocus compensation module 4 includes a scanning objective lens 401, a field flattener objective lens 402, and a guide rail 403, the extending direction of the guide rail 403 coincides with the central axis direction of the field flattener objective lens 402, and the field flattener objective lens 402 is slidably disposed on the guide rail 403. After the incident light is emitted from the light beam scanning module 3, the incident light sequentially passes through the scanning objective lens 401 and the flat field objective lens 402, and the control module 9 controls the flat field objective lens 402 to reciprocate along the central axis of the flat field objective lens 402, so that the ametropia of the human eye is compensated.

(3) Guiding and fixing vision of visual target

The sighting target module 6 comprises an LED array 601, a lens 602 and a first dichroic beam splitter 603, one LED lamp bead in the LED array 601 is lightened through a control module 9, light emitted by the LED lamp bead reaches the first dichroic beam splitter 603 through the lens 602, is reflected by the first dichroic beam splitter 603, enters the flat field objective 402 for transmission, sequentially passes through the scanning objective 401, the flat field objective 402 and the second dichroic beam splitter 702, then passes through a hollow part of the annular LED array 701, then reaches human eyes, and is focused on fundus retinas through an optical system of the human eyes.

The human eyes watch the LED luminous points to realize fixation.

By the control module 9 lighting up the lamp beads at different positions on the LED array 601, different areas of the fundus retina will be guided to be imaging areas.

3. Adaptive optical aberration measurement and correction process

The returned imaging light carrying the aberration information and the light intensity information of the human eye is emitted through the light beam scanning module 3 to enter the transmission type or reflection type telescope 203, and then is reflected to the second spectroscope 201 by the wavefront corrector 202, part of the imaging light is reflected to the wavefront sensor 204 by the second spectroscope 201, so that the wavefront aberration measurement is realized, and the rest imaging light is transmitted through the second spectroscope 201 to continue to be transmitted; after receiving the light beam containing the human eye aberration information, the wavefront sensor transmits the light beam to the control module 9, the control module 9 obtains a wavefront correction voltage through wavefront calculation and outputs the wavefront correction voltage to the wavefront corrector 202, and the wavefront corrector 202 realizes real-time correction of the human eye aberration.

4. Scanning imaging process

The beam scanning module 3 includes a first scanning mirror 301 and a second scanning mirror 303, which are connected through a transmission telescope or a reflection telescope 302 to realize pupil surface matching. The front and back positions of the first scanning mirror 301 and the second scanning mirror 303 can be interchanged, and the imaging effect is not influenced. The first scanning mirror 301 and the second scanning mirror 303 are controlled by the output voltage signal of the control module 9, and can be configured into different scanning modes to realize different imaging functions.

(1) The large-view-field imaging function is realized by the following steps:

the self-adaptive optical module 2 is in a power-off state or a power-on non-operating state;

the first scanning mirror 301 realizes the transverse scanning of the retinal plane under the driving of a periodic voltage signal; the second scan mirror 303 is driven by a periodic voltage signal to effect a longitudinal scan of the retinal plane. The retina scanning angles of the first scanning mirror 301 and the second scanning mirror 303 driven by periodic voltage signals are not less than 20 degrees;

the detection module 8 converts the acquired fundus retina optical signals into electric signals, the control module 9 synchronizes the periodic driving voltage signals of the first scanning mirror 301 and the second scanning mirror 303, and the control module 9 samples and reconstructs the electric signals to obtain a retina large-field imaging image and outputs the retina large-field imaging image to the output module 10 for displaying, storing, processing and other functions.

(2) The small visual field high resolution imaging function is realized by the following steps:

the self-adaptive optical module 2 is in a starting working state, so that the measurement and correction of wavefront aberration are realized;

the first scanning mirror 301 realizes the transverse scanning of the retinal plane under the driving of a periodic voltage signal; the second scanning mirror 303 can generate certain transverse and longitudinal inclination angles under the driving of a direct current voltage signal, is used for positioning a light beam for illuminating the fundus retina at an interested position, and then realizes longitudinal scanning on a retina plane under the driving of a periodic voltage signal; the retina scanning angles of the first scanning mirror 301 and the second scanning mirror 303 driven by the periodic voltage signals are not more than 5 degrees;

the direct current voltage signal is obtained by calculation of the control module 9 according to the coordinate position of the eye fundus retina;

the detection module 8 converts the acquired fundus retina optical signals into electric signals, the control module 9 synchronizes the periodic driving voltage signals of the first scanning mirror 301 and the second scanning mirror 303, the control module 9 samples and reconstructs the electric signals to obtain a retina small visual field high-resolution imaging image, and meanwhile, the fundus retina coordinate position is marked in the imaging image; the small-field high-resolution imaging image is output to an output module 10 through a control module 9 to perform functions of displaying, storing, processing and the like.

(3) The large-field high-resolution imaging function is realized by the following steps:

the self-adaptive optical module 2 is in a starting working state, so that the measurement and correction of wavefront aberration are realized;

the first scanning mirror 301 realizes the transverse scanning of the retinal plane under the driving of a periodic voltage signal; the second scanning mirror 303 is driven by a periodic voltage signal to realize longitudinal scanning on the plane of the retina; the retina scanning angles of the first scanning mirror 301 and the second scanning mirror 303 driven by the periodic voltage signals are not more than 5 degrees;

at the moment, the second scanning mirror 303 can generate certain transverse and longitudinal inclination angles under the driving of the direct-current voltage signal, light beams are sequentially inclined to illuminate each region of the fundus retina, the single transverse and longitudinal inclination angle of the second scanning mirror 303 is not more than 3 degrees, and the maximum transverse and longitudinal inclination angle of the retina of the second scanning mirror 303 under the driving of the direct-current voltage signal is not more than 15 degrees; the direct current voltage signal is obtained by calculation of the control module 9 according to the coordinate position of the eye fundus retina;

when each area of the fundus retina is sequentially illuminated by the light beam, the control module 9 can obtain a high-resolution imaging image of each area of the retina, the control module 9 splices the images according to the position coordinates of the fundus retina of each area high-resolution imaging image to obtain a large-field high-resolution image of the fundus retina, and then the large-field high-resolution image is output to the output module 10 to perform functions of displaying, storing, processing and the like.

The invention also provides a common-path light beam scanning large-field-of-view adaptive optical retina imaging method, which adopts the system for imaging and refers to fig. 3, and the method comprises the following steps:

step S1: starting up the system;

step S2: the head of a testee is placed on the head support frame, the pupil monitoring module 7 is started, and the three-dimensional translation of the head support frame is automatically adjusted through the manual adjusting or control module 9, so that the pupil is imaged in the middle area of a visual field;

step S3: manually sliding the flat field objective lens 402 to move along the center of the optical axis, or driving a motor through a control module 9 to move the position of the flat field objective lens 402 on a guide rail 403, so as to realize compensation and correction of ametropia of the human eye;

step S4: a lamp bead in the LED array 601 is lightened, and a subject watches the light spot to realize fixation;

step S5: the self-adaptive optical module 2 is in a shutdown or startup non-operating state, the light beam scanning module 3 is set to be in a large visual field scanning mode, and the control module 9 controls the light beam scanning module 3 to complete large visual field scanning, so that large visual field imaging of retina is realized and output to the output module 10;

step S6: the self-adaptive optical module 2 is started to work and is used for realizing wavefront aberration measurement and correction, and the control module 9 controls the light beam scanning module 3 to carry out small-field scanning;

step S61: the control module 9 controls the light beam scanning module 3 to complete outputting of the small-field high-resolution imaging image to the output module 1010;

step S62: the control module 9 controls the light beam scanning module 3 to complete a large-field high-resolution imaging image and output the large-field high-resolution imaging image to the output module 10.

Wherein, the sequence of step S5 and step S6 can be reversed.

When the operation of step S6 is completed, step S61 and step S62 may perform a selection operation according to actual needs.

As is known, the existing laser confocal scanning ophthalmoscope has a large imaging field of view, but the resolution is not enough to observe the retina microstructure; the laser confocal scanning ophthalmoscope combined with the adaptive optics can observe the retina microstructure, but the imaging field of view is small, and the focus condition of a larger field of view cannot be observed.

Compared with the technical achievements in the laser confocal scanning imaging field at home and abroad, the invention provides a large-field-of-view adaptive optical retina imaging system for light beam scanning in a common light path on the basis of the basic principle of combining adaptive optics with a confocal scanning technology, and the common light path structure of two scanning mirrors is adopted, and the two scanning mirrors are configured into different scanning imaging modes, so that large-field-of-view imaging exceeding 20 degrees can be completed on a retina for observing a focus area of a retinal disease; the small-field scanning imaging of not more than 5 degrees can be completed on the retina, the fine structure and pathological changes of the focus can be observed through small-field high-resolution imaging under the condition of self-adaptive optical correction aberration, the second scanning mirror 302 is further arranged to realize that light beams are sequentially obliquely illuminated in each area of the retina, and then the large-field high-resolution imaging of more than 15 degrees of the retina can be obtained at one time through image splicing.

The invention provides a large-field-of-view self-adaptive optical retina imaging system for light beam scanning in a common light path. The first scanning mirror 301 realizes transverse scanning on the retina, the second scanning mirror 303 realizes longitudinal scanning on the retina, and meanwhile, the second scanning mirror 303 can realize transverse and longitudinal inclination under the driving of direct current voltage to realize the positioning of the illumination light beam to the interested area of the retina.

Different scanning imaging functions can be realized by controlling the two scanning mirrors to be in different scanning modes.

(1) Large field of view scan imaging

The first scanning mirror 301 is in registration with transverse scanning, the second scanning mirror 303 is configured to be in longitudinal scanning, the retina scanning angles of the two scanning mirrors are not less than 20 degrees, at the moment, the adaptive optical correction function is invalid, and the imaging lens is in a shutdown state or a startup non-operation state to acquire a retina large-field imaging image.

(2) Small field of view high resolution imaging

The first scanning mirror 301 is registered as transverse scanning, the second scanning mirror 303 is configured as longitudinal scanning, the retina scanning angles of the two scanning mirrors are not more than 5 degrees, at the moment, the self-adaptive optics finishes the functions of measuring and correcting the aberration, and a retina small-field high-resolution imaging image after aberration correction is acquired. The second scanning mirror 303 can also generate transverse and longitudinal inclination under the driving of the direct-current voltage signal, and is used for positioning the light beam for illuminating the fundus retina at the interested position, so that small-field high-resolution imaging observation of any interested position of the retina can be realized.

(3) Large field of view high resolution imaging

The first scanning mirror 301 is registered as transverse scanning, the second scanning mirror 303 is configured as longitudinal scanning, the retina scanning angles of the two scanning mirrors are not more than 5 degrees, at the moment, the self-adaptive optics finishes the functions of measuring and correcting the aberration, and a retina small-field high-resolution imaging image after aberration correction is acquired. The second scanning mirror 303 can also generate transverse and longitudinal inclination under the driving of the direct-current voltage signal, position the light beam for illuminating the fundus retina at the interested position, configure to incline the light beam for illuminating each area of the fundus retina in turn, the single transverse and longitudinal inclination angle of the second scanning mirror 303 is not more than 3 degrees, and the maximum transverse and longitudinal inclination angle of the retina of the second scanning mirror 303 under the driving of the direct-current voltage is not more than 15 degrees.

When each area of the fundus retina is sequentially illuminated by the light beam, a high-resolution imaging image of each area of the retina can be obtained, and the control module 9 splices the images according to the position coordinates of the fundus retina of the high-resolution imaging image of each area to obtain a large-field high-resolution imaging image of the fundus retina.

The large-view-field adaptive optical retina imaging system and method based on common-path beam scanning can acquire large-view-field imaging images of fundus retina, small-view-field high-resolution imaging images of any interested area and large-view-field high-resolution imaging images, and the three types of imaging images are acquired by a common-path structure, so that the three types of imaging images have good feature consistency and are convenient to process and operate. Meanwhile, the system is simple in structure, and three types of retina imaging images can be acquired through the common light path structure: by switching different synchronous scanning modes, the retina disease focus area can be observed through large-view-field imaging, and the focus microstructure can also be observed through small-view-field high-resolution imaging. The large-field imaging image can observe the characteristics of structures, focuses and the like of the retina in a large range, the small-field high-resolution imaging image can observe the fine structure of any interested region, and the large-field high-resolution imaging image can observe the fine structure of the retina in the large range. Various imaging images are obtained through common-path light beam scanning, the requirements of different application scenes are met, and the application range of retina imaging is greatly enlarged.

While embodiments of the invention have been disclosed above, it is not limited to the applications listed in the description and the embodiments, which are fully applicable in all kinds of fields of application of the invention, and further modifications may readily be effected by those skilled in the art, so that the invention is not limited to the specific details without departing from the general concept defined by the claims and the scope of equivalents.