A retinal imaging device and its imaging method

Abstract

This invention provides a retinal imaging device and its imaging method. The retinal imaging device includes a light source detection module, a beam modulation module, and an acquisition control module. The light source detection module generates a light source that is incident on the beam modulation module. The beam modulation module modulates the incident angle of the beam, and the modulated beam enters the eyeball. The feedback beam, reflected by the retina, passes through the beam modulation module and is incident on the light source detection module. The light source detection module generates a detection signal. The acquisition control module controls the optical path state of the beam modulation module based on this detection signal. This invention combines confocal scanning and optical coherence tomography (OCT) to achieve real-time eye movement tracking, eliminate the influence of eye movement, and improve the acquisition efficiency of three-dimensional imaging. Simultaneously, by utilizing adaptive optics and adding a compensation mirror and wavefront detector, real-time aberration compensation can be achieved, significantly improving the quality of retinal three-dimensional imaging images and obtaining high-resolution images at the cell level.

Description

Technical Field

[0001] This invention relates to the field of optical design technology, and more specifically, to a retinal imaging device and imaging method thereof. Background Technology

[0002] The retina is an important part of the human eye. Currently, more than one billion people worldwide suffer from retinal-related diseases. In order to achieve more effective treatment of retinal-related diseases, the optimization of treatment devices is essential. In other words, high-resolution imaging devices for the retina are of great significance for the diagnosis and efficacy evaluation of retinal-related diseases.

[0003] Early retinal imaging devices were mainly based on slit lamps or fundus cameras, but these techniques were affected by aberrations in the imperfect human eye, resulting in low imaging resolution and an inability to observe the microscopic cellular structure of the retina.

[0004] Researchers Liang Junzhong et al. (Liang et al. “Supernormal vision and high-resolution retinal imaging through adaptive optics”, J.Opt.Soc.Am.A / Vol.14, No.11 / Nov.1997) proposed a confocal adaptive optics retinal imaging device that can dynamically detect in real time, compensate for human eye aberrations, and improve lateral resolution by an order of magnitude. However, the longitudinal resolution of this retinal imaging device is low and it cannot distinguish the multi-layered structure of the retina.

[0005] Researchers Donald Miller et al. (Yan Zhang, Jungtae Rha, Ravi S. Jonnal, and Donald T. Miller, “Adaptive optics parallel spectral domain optical coherencetomography for imaging the living retina”, Optics Express, Vol. 13, No. 12 / Jun. 2005) proposed an imaging device combining optical coherence tomography (OCT) with adaptive optics, which can further improve longitudinal resolution while maintaining high lateral resolution. However, this imaging device uses single-channel flood illumination, cannot track eye movements, and image acquisition is affected by human eye movements. Common eye movements can cause image tearing and blurring, resulting in low image usability. Therefore, in order to obtain usable images, this imaging device needs to repeatedly acquire images, which leads to long acquisition times and low clinical efficiency.

[0006] Therefore, how to provide a high-performance retinal imaging device is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0007] In view of this, to solve the above problems, the present invention provides a retinal imaging device and an imaging method thereof, the technical solution of which is as follows:

[0008] A retinal imaging device, the retinal imaging device comprising: a light source detection module, a beam modulation module, and an acquisition control module;

[0009] The light source detection module is used to generate reflected light or dual-channel illumination light including reflected light and OCT light. The reflected light or the dual-channel illumination light is combined to form a scanning beam that is incident on the beam modulation module.

[0010] The beam modulation module is used to modulate the incident angle of the scanning beam. The modulated scanning beam enters the eyeball, and the feedback beam reflected by the retina passes through the beam modulation module and is incident on the light source detection module.

[0011] The light source detection module is also used to generate a detection signal based on the feedback beam;

[0012] The acquisition and control module is used to acquire the detection signal and control the optical path state of the beam modulation module based on the detection signal to achieve eye movement tracking.

[0013] Preferably, in the above-mentioned retinal imaging device,

[0014] (1) When the light source detection module generates reflected light, the beam modulation module includes: three conjugate surfaces of the pupil of the eyeball to form three images of the human pupil; and a first to a third galvanometer is placed on the three conjugate surfaces of the pupil of the eyeball respectively;

[0015] The first galvanometer is used for lateral scanning of the reflected light;

[0016] The second galvanometer is used for longitudinal scanning and longitudinal tracking of the reflected light;

[0017] The third galvanometer is used for lateral tracking of the reflected light;

[0018] (2) When the light source detection module generates dual-channel illumination light

[0019] The beam modulation module includes: three pupil conjugate surfaces to form three images of the human eye pupil; and first to third galvanometers are respectively placed on the three pupil conjugate surfaces.

[0020] The first galvanometer is used for lateral scanning of the reflected light and lateral scanning of the OCT light;

[0021] The second galvanometer is used for longitudinal scanning and longitudinal tracking of the reflected light and the OCT light;

[0022] The third galvanometer is used for lateral tracking of the reflected light and the OCT light;

[0023] Alternatively, the beam modulation module includes: four conjugate surfaces of the pupil to form four images of the human pupil; and first to fourth galvanometers are respectively placed on the four conjugate surfaces of the pupil.

[0024] The first galvanometer is used for lateral scanning of the reflected light;

[0025] The second galvanometer is used for lateral scanning of the OCT light;

[0026] The third galvanometer is used for longitudinal scanning and longitudinal tracking of the reflected light and the OCT light;

[0027] The fourth galvanometer is used for lateral tracking of the reflected light and the OCT light.

[0028] Preferably, in the above-mentioned retinal imaging device, the beam modulation module is further provided with an eyeball pupil conjugate surface for placing a compensation mirror; the compensation mirror is used for real-time aberration compensation.

[0029] Preferably, in the above-mentioned retinal imaging device, the light source detection module includes: a light source and a photodetector;

[0030] When the light source generates dual-channel illumination light, the light source detection module also includes an OCT detector;

[0031] The photodetector is used to generate a reflected light detection signal based on the reflected light in the feedback beam; the OCT detector is used to generate an OCT light detection signal based on the OCT light in the feedback beam.

[0032] Preferably, in the above-mentioned retinal imaging device, the acquisition control module includes: a data acquisition unit, a galvanometer control unit, and a computing unit;

[0033] The data acquisition unit is used to acquire the reflected light detection signal, or simultaneously acquire the OCT light detection signal;

[0034] The computing unit is used to generate a two-dimensional reflection image based on the reflected light detection signal, or simultaneously generate the three-dimensional retinal image based on the OCT light detection signal; the computing unit is also used to generate a first control signal based on the two-dimensional reflection image;

[0035] The galvanometer control unit is used to control the deflection state of the galvanometer in the beam modulation module according to the first control signal, so as to realize eye movement tracking.

[0036] Preferably, in the above-mentioned retinal imaging device, the light source detection module further includes a wavefront detector, which is used to generate a wavefront detection signal based on a portion of the reflected light in the feedback beam.

[0037] Preferably, in the above-mentioned retinal imaging device, the acquisition control module includes: a data acquisition unit, a galvanometer control unit, a compensating mirror control unit, and a computing unit;

[0038] The data acquisition unit is used to acquire the reflected light detection signal and the wavefront detection signal, or simultaneously acquire the OCT light detection signal;

[0039] The computing unit is used to generate a two-dimensional reflection image based on the reflected light detection signal, and to generate a wavefront image based on the wavefront detection signal, or simultaneously generate the three-dimensional retinal image based on the OCT light detection signal; the computing unit is also used to generate a first control signal based on the two-dimensional reflection image, and to generate a second control signal based on the wavefront image.

[0040] The galvanometer control unit is used to control the deflection state of the galvanometer in the beam modulation module according to the first control signal to achieve eye movement tracking; the compensation mirror control unit is used to control the compensation value of the compensation mirror in the beam modulation module according to the second control signal to achieve real-time aberration compensation.

[0041] Preferably, in the above-mentioned retinal imaging device, the reflected light includes light of multiple different wavelengths, and the computing unit generates a colored two-dimensional reflection image based on the reflected light detection signal.

[0042] A retinal imaging method, based on the retinal imaging device described in any one of the preceding claims, the retinal imaging method comprising:

[0043] The light source detection module generates reflected light or dual-channel illumination light including reflected light and OCT light, and forms a scanning beam that is incident on the beam modulation module. The beam modulation module modulates the incident angle of the scanning beam and causes the modulated scanning beam to enter the eyeball. The feedback beam reflected by the retina passes through the beam modulation module and is incident on the light source detection module. The light source detection module generates a detection signal based on the feedback beam. The acquisition control module acquires the detection signal and controls the optical path state of the beam modulation module based on the detection signal to achieve eye movement tracking.

[0044] Preferably, in the above-mentioned retinal imaging method, the light source detection module further generates a wavefront detection signal based on a portion of the reflected light in the feedback beam, the acquisition control module acquires the wavefront detection signal, and controls the optical wavefront phase of the scanning beam based on the wavefront detection signal to achieve real-time aberration compensation.

[0045] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0046] This retinal imaging device combines confocal imaging scanning with optical coherence tomography (OCT) to achieve real-time eye movement tracking, eliminating the influence of eye movement and improving the acquisition efficiency of 3D imaging. Simultaneously, by utilizing adaptive optics technology and incorporating a compensation mirror and wavefront detector, real-time aberration compensation can be achieved, significantly improving the quality of retinal 3D imaging and obtaining high-resolution images at the cellular level. Furthermore, this retinal imaging device utilizes the conjugate surface of the pupil, offering the advantage of a simple optical path. Attached Figure Description

[0047] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0048] Figure 1 This is a schematic diagram of the principle structure of a retinal imaging device provided in Embodiment 1 of the present invention;

[0049] Figure 2 This is a schematic diagram of the principle structure of a retinal imaging device provided in Embodiment 2 of the present invention;

[0050] Figure 3 This is a schematic diagram of the structure of a data acquisition and control module provided in Embodiment 1 of the present invention;

[0051] Figure 4 This is a schematic diagram of the dual-channel scanning control logic of a retinal imaging device provided in Embodiment 1 of the present invention;

[0052] Figure 5 This is a schematic diagram of the structure of a data acquisition and control module provided in Embodiment 2 of the present invention;

[0053] Figure 6 This is a schematic diagram of the dual-channel scanning control logic of a retinal imaging device provided in Embodiment 2 of the present invention. Detailed Implementation

[0054] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0055] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0056] refer to Figure 1 and Figure 2 A retinal imaging device according to an embodiment of the present invention includes: a light source detection module, a beam modulation module, and an acquisition control module;

[0057] The light source detection module is used to generate a light source, which is reflected light or a dual-channel illumination light including reflected light and OCT light. The reflected light or the dual-channel illumination light is combined to form a scanning beam that is incident on the beam modulation module.

[0058] The beam modulation module is used to modulate the incident angle of the scanning beam. The modulated scanning beam enters the eyeball, and the feedback beam reflected by the retina passes through the beam modulation module and is incident on the light source detection module.

[0059] The light source detection module is also used to generate a detection signal based on the feedback beam;

[0060] The acquisition and control module is used to acquire the detection signal and control the optical path state of the beam modulation module based on the detection signal to achieve eye movement tracking.

[0061] Specifically, the light source detection module generates reflected light or dual-channel illumination light. One of the dual-channel illumination lights is reflected light (used to illuminate the retina and generate reflected signals), and the other is OCT light (used to illuminate the retina and generate interference signals). After being combined inside or outside the beam detection module, a scanning beam is formed and enters the beam modulation module.

[0062] The beam modulation module modulates at least the incident angle of the scanning beam and ensures that the modulated scanning beam enters the eyeball.

[0063] The feedback beam reflected by the retina returns to the light source detection module via the same path; that is, the feedback beam reflected by the retina is incident on the light source detection module after passing through the beam modulation module.

[0064] The light source detection module processes the feedback beam to generate a corresponding detection signal, which is then acquired and processed by the acquisition and control module.

[0065] Specifically, the acquisition and control module acquires the detection signal and controls the optical path state of the beam modulation module based on the detection signal to at least achieve eye movement tracking.

[0066] Furthermore, such as Figure 1 As shown, when the light source is a dual-channel illumination light, the light sources used in the light source detection module are a reflected light source and an OCT light source. The reflected light source outputs reflected light, and the OCT light source outputs OCT light. In this case, an OCT detector can be set in the light source detection module to generate an OCT light detection signal based on the OCT light in the feedback beam. Correspondingly, the acquisition control module acquires the OCT detection signal and generates a three-dimensional retinal image based on it.

[0067] It should be noted that reflected light sources and OCT light sources can be like... Figure 1 The image shows two independent light source devices, which output reflected light and OCT light respectively; it can also be shown as follows: Figure 2The diagram shows a beam of light emitted from an OCT light source, serving as both reflected light and OCT light. This beam is reflected by the eye and split into two beams by optics in the light source detection module, which are then received by a photodetector and an OCT detector, respectively. The reflected light source can emit light of a single wavelength, multiple wavelengths, or multiple reflected light sources with different wavelengths can be used. For example, if three lasers (red, green, and blue) are used as the reflected light source and received by three photodetectors, a colored two-dimensional reflected image can be obtained, providing richer retinal information.

[0068] Furthermore, the beam modulation module may also include a compensation mirror, and the light source detection module may include a wavefront detector. The wavefront detector generates a wavefront detection signal based on a portion of the reflected light from the feedback beam. Correspondingly, the acquisition and control module acquires the wavefront detection signal and controls the compensation value of the compensation mirror based on the detection signal to achieve real-time aberration compensation.

[0069] Example 1

[0070] like Figure 1 As shown, when the light source is dual-channel illumination light, the light source detection module includes: a reflected light source, an OCT light source, an optical fiber coupler, a beam splitter C1, a beam splitter C2, a beam splitter C3, a lens, a pinhole, a photodetector, an OCT detector, and a wavefront detector.

[0071] Specifically, when the retinal imaging device is working, the reflected light source and the OCT light source are first turned on. The OCT light output from the OCT light source is collimated and incident on the beam splitter C1 after passing through the fiber optic coupler. The reflected light output from the reflected light source passes through the beam splitter C2 and is combined with the OCT light at the beam splitter C1. The combined scanning beam passes through the reflector SM1 and enters the beam modulation module. The reflector SM1 can be set in the beam modulation module.

[0072] Furthermore, the feedback beam reflected by the retina returns to the light source detection module via the same path. Specifically, the feedback beam, after being reflected by the retina, passes through the beam modulation module and is incident on the light source detection module. The OCT light in the feedback beam is reflected back to the fiber coupler by beam splitter C1, and then reaches the OCT detector. The OCT detector generates an OCT light detection signal CJ3 based on the OCT light in the feedback beam. The reflected light from the feedback beam is projected onto beam splitters C1 and C2. A portion of the reflected light is reflected by beam splitter C3 to reach the wavefront detector, while the other portion is projected onto beam splitter C3, focused by a lens, and reaches the photodetector through a small aperture. The photodetector generates a reflected light detection signal CJ2 based on a portion of the reflected light from the feedback beam, and the wavefront detector generates a wavefront detection signal CJ1 based on the other portion of the reflected light from the feedback beam.

[0073] The beam modulation module of this embodiment includes: mirror SM2, beam splitter C4, mirror SM3, mirror SM4, mirror SM5, mirror SM6, mirror SM7, mirror SM8, mirror SM9, mirror SM10 and mirror P1.

[0074] In other words, the beam modulation module has five pupil conjugate surfaces, which are optically conjugate with the pupil through nine reflecting mirrors SM2-SM10 and a beam splitter C4. Four galvanometers (i.e., the first to fourth galvanometers) and one compensation mirror are placed on these five optical conjugate surfaces. The first galvanometer G1 is used for lateral scanning of the reflected light; the second galvanometer G2 is used for lateral scanning of the OCT light; the third galvanometer G3 is used for longitudinal scanning and tracking of both the reflected and OCT light; the fourth galvanometer G4 is used for lateral tracking of both the reflected and OCT light; and the compensation mirror is used for real-time aberration compensation. The placement order of the first to fourth galvanometers and the compensation mirror is not fixed and can be adjusted or interchanged arbitrarily in the optical path. If it is necessary to reduce the number of pupil conjugate surfaces, the number of reflecting mirrors and galvanometers / compensation mirrors in the optical path can be reduced accordingly. The pupil conjugate surfaces can also be implemented using a lens-like structure.

[0075] Specifically, the scanning beam output by the light source detection module enters the beam modulation module through the reflector SM1, is reflected by the reflector SM2 and then incident on the beam splitter C4. The reflected light is projected onto the beam splitter C4 and then reflected by the first galvanometer G1. After being projected onto the beam splitter C4 a second time, it reaches the reflector SM3.

[0076] The OCT light undergoes its first reflection at beam splitter C4, is reflected again by the second galvanometer G2, and then undergoes a second reflection by beam splitter C4 before reaching the reflecting mirror SM3.

[0077] After the reflected light and OCT light reach the reflector SM3, they pass through the reflector SM4, the third galvanometer G3, the reflector SM5, the reflector SM6, the compensating mirror, the reflector SM7, the reflector SM8, the fourth galvanometer G4, the reflector SM9, the reflector SM10, and the reflector P1 to reach the eyeball, that is, to the retina of the eyeball.

[0078] The feedback beam reflected by the retina returns to the light source detection module via the same path; that is, the feedback beam reflected by the retina returns to the light source detection module after passing through the beam modulation module.

[0079] Optionally, in the embodiments of this application, the beam splitter includes, but is not limited to, dichroic mirrors, flat beam splitters, thin-film beam splitters, cubic beam splitters, etc.; the compensation mirror, as a wavefront aberration compensation device for the human eye, includes, but is not limited to, deformable mirrors, spatial light modulators, etc.; the first to fourth galvanometers, as reflectors with adjustable angles, include, but are not limited to, resonant mirrors, scanning galvanometers, acousto-optic modulators, MEMS galvanometers, etc.

[0080] It should be noted that, in the embodiments of this application, the optical path topology of the light source detection module is only an optimal optical path structure, which has the advantages of simple optical path structure and better performance. In other embodiments, it can also be other forms of optical path topology. For dual-channel illumination light, it is only necessary to meet the core functions of incident dual-channel light beam combining and outgoing dual-channel light beam splitting.

[0081] Optionally, in the embodiments of this application, the beam splitter includes, but is not limited to, dichroic mirrors, flat beam splitters, thin-film beam splitters, cubic beam splitters, etc.; the light source includes, but is not limited to, superluminescent diodes, vertical-cavity surface-emitting lasers, sapphire lasers, etc., which can emit a wide spectral range; wherein, the OCT detector includes, but is not limited to, spectrometers, balanced detectors, etc.; the wavefront detector includes, but is not limited to, microlens wavefront sensors, interferometric wavefront sensors, etc.; the photodetector includes, but is not limited to, photomultiplier tubes, avalanche photodiodes, etc.

[0082] Based on this, refer to Figure 3 This embodiment provides a schematic diagram of the acquisition and control module.

[0083] The acquisition and control module includes: a data acquisition unit, a galvanometer control unit, a compensation mirror control unit, and a computing unit;

[0084] The data acquisition unit is used to acquire the reflected light detection signal and the wavefront detection signal, and also to acquire the OCT light detection signal simultaneously.

[0085] The computing unit is used to generate a two-dimensional reflection image based on the reflected light detection signal, and to generate a wavefront image based on the wavefront detection signal, and also to generate the three-dimensional retinal image based on the OCT light detection signal; the computing unit is also used to generate a first control signal based on the two-dimensional reflection image, and to generate a second control signal based on the wavefront image.

[0086] The galvanometer control unit is used to control the deflection state of the galvanometer in the beam modulation module according to the first control signal, thereby achieving eye movement tracking. The first control signal includes: a first galvanometer control signal K1, used to control the deflection state of the first galvanometer G1; a second galvanometer control signal K2, used to control the deflection state of the second galvanometer G2; a third galvanometer control signal K3, used to control the deflection state of the third galvanometer G3; and a fourth galvanometer control signal K4, used to control the deflection state of the fourth galvanometer G4. Since the deflection angle of the galvanometer is directly proportional to the position of the light spot on the retina, exhibiting a linear relationship, controlling the deflection angle of the galvanometer can achieve eye scanning and tracking functions.

[0087] The compensation mirror control unit is used to control the compensation value of the compensation mirror in the beam modulation module according to the second control signal, so as to realize real-time aberration compensation.

[0088] In this embodiment, the data acquisition unit acquires the OCT light detection signal CJ3 generated by the OCT detector, the reflected light detection signal CJ2 generated by the light detector, and the wavefront detection signal CJ1 generated by the wavefront detector in the light source detection module. These three signals are transmitted to the computing unit for signal processing to generate a three-dimensional retinal image, a two-dimensional reflection image, and a wavefront image, respectively. The computing unit generates a first control signal based on the two-dimensional reflection image and a second control signal based on the wavefront image. The galvanometer control unit controls the deflection of the first to fourth galvanometers in the beam modulation module based on the first control signal to achieve real-time eye movement tracking; the compensation mirror control unit controls the compensation value of the compensation mirror based on the second control signal to compensate for real-time aberrations of the human eye.

[0089] Specifically, the acquisition and control module has three input signals and five output signals. The three input signals are the OCT light detection signal CJ3, the reflected light detection signal CJ2, and the wavefront detection signal CJ1 acquired by the data acquisition unit. The five output signals are the first galvanometer control signal K1, the second galvanometer control signal K2, the third galvanometer control signal K3, the fourth galvanometer control signal K4, and the second control signal K5 that controls the compensation value of the compensation mirror. The control logic of the device is described in detail below in this embodiment. (Refer to...) Figure 4 This is a schematic diagram of the dual-channel scanning control logic of a retinal imaging device provided in this embodiment.

[0090] Specifically, Figure 4 The solid line represents reflected light, and the dashed line represents OCT light.

[0091] The transverse scanning signal of the reflected light is superimposed on the first galvanometer control signal K1 to drive the first galvanometer G1.

[0092] The longitudinal scanning signal of the reflected light is superimposed on the control signal K3 of the third galvanometer to drive the third galvanometer G3.

[0093] The lateral tracking signal of the reflected light is superimposed on the control signal K4 of the fourth galvanometer to drive the fourth galvanometer G4.

[0094] The longitudinal tracking signal of the reflected light is superimposed on the control signal K3 of the third galvanometer to drive the third galvanometer G3.

[0095] The transverse scanning signal of the OCT light is superimposed on the control signal K2 of the second galvanometer to drive the second galvanometer G2.

[0096] The longitudinal scanning signal of the OCT light is superimposed on the control signal K3 of the third galvanometer to drive the third galvanometer G3.

[0097] The lateral tracking signal of the OCT light is superimposed on the control signal K4 of the fourth galvanometer to drive the fourth galvanometer G4.

[0098] The longitudinal tracking signal of the OCT light is superimposed on the control signal K3 of the third galvanometer to drive the third galvanometer G3.

[0099] Specifically, the principle of real-time wavefront aberration compensation during the operation of a retinal imaging device is as follows:

[0100] After the data acquisition unit in the acquisition control module acquires the wavefront detection signal, the calculation unit calculates the human eye aberration and obtains the second control signal. The compensation mirror control unit drives the compensation mirror to modulate the opposite value of the wavefront to the human eye aberration through the second control signal K5, which cancels out the human eye aberration, thus realizing the function of human eye wavefront aberration compensation.

[0101] Specifically, during the operation of the retinal imaging device, because the acquisition frequencies of the photodetector and the OCT detector are inconsistent, and the speed of the OCT detector is generally slower than that of the reflective photodetector, the scanning method used in this embodiment is as follows:

[0102] Reflected light scanning: The galvanometer control unit controls the lateral scanning field size and frequency of the reflected light by controlling the vibration amplitude and frequency of the first galvanometer G1 deflection angle through the first galvanometer control signal K1; and controls the longitudinal scanning field size and frequency of the reflected light by controlling the vibration amplitude and frequency of the third galvanometer G3 deflection angle through the third galvanometer control signal K3.

[0103] OCT light scanning: The galvanometer control unit controls the lateral scanning field size and frequency of the OCT light by controlling the vibration amplitude and frequency of the second galvanometer G2 deflection angle through the second galvanometer control signal K2; and controls the longitudinal scanning field size and frequency of the reflected light by controlling the vibration amplitude and frequency of the third galvanometer G3 deflection angle through the third galvanometer control signal K3.

[0104] Lateral scanning of reflected light and OCT light is achieved through different galvanometers (i.e., the first galvanometer G1 and the second galvanometer G2), which can operate at different lateral frequencies. Typically, the lateral frequency of reflected light is higher than that of OCT light.

[0105] The longitudinal scanning of reflected light and OCT light is achieved through the same galvanometer (i.e., the third galvanometer G3), and the longitudinal field of view size and frequency of the two channels are kept consistent.

[0106] This embodiment uses a combination of the first galvanometer G1 and the second galvanometer G2, which can ensure that the photodetector and the OCT detector scan the same area at different speeds and share most of the components, making the retinal imaging device smaller and thus saving device costs.

[0107] Specifically, the principle of real-time eye movement tracking during the operation of a retinal imaging device is as follows:

[0108] The data acquisition unit of the acquisition control module amplifies the reflected light signal in multiple stages. After analog-to-digital conversion, the calculation unit generates a real-time two-dimensional retinal reflection image. After the calculation unit calculates the horizontal and vertical relative displacement values ​​of the current frame of the two-dimensional reflection image relative to the previous frame, it superimposes a horizontal and vertical deflection value equal to the above relative displacement value onto the fourth galvanometer control signal K4 and the third galvanometer control signal K3 of the galvanometer control unit, respectively. This ensures that the position of the scanning field of view of the reflected light and the OCT light relative to the retina remains unchanged, thereby realizing real-time eye movement tracking.

[0109] As can be seen from the above description, this embodiment provides a method such as Figure 1 The retinal imaging device shown improves the axial resolution by about an order of magnitude by adding an OCT light source while maintaining the high lateral resolution of adaptive optics confocal scanning. This achieves three-dimensional micron-level resolution and can acquire three-dimensional cellular-level imaging of the multi-layered structure of the retina.

[0110] Furthermore, in this embodiment, the pupil conjugate surface four-mirror scanning structure and the compensation mirror of the beam modulation module simultaneously realize three major functions: three-dimensional imaging, real-time eye movement tracking, and human eye wavefront aberration compensation. This solves problems such as image tearing and blurring caused by human eye movement, improves the quality of a single image and the success rate of image acquisition, thereby improving the acquisition rate in clinical environments.

[0111] Example 2

[0112] like Figure 2 As shown, this embodiment provides an imaging device with another light source, dual-channel illumination light. Its beam modulation module includes four pupil conjugate surfaces to form four images of the human eye pupil; a first to a third galvanometer and a compensation mirror are placed on the four pupil conjugate surfaces.

[0113] In this embodiment, such as Figure 2 As shown, the light source detection module includes: an OCT light source, an optical fiber coupler, a beam splitter C1, a beam splitter C2, a lens, a pinhole, an OCT detector, a photodetector, and a wavefront detector.

[0114] The beam modulation module includes: a reflector SM2, a first galvanometer M1, a reflector SM3, a reflector SM4, a second galvanometer M2, a reflector SM5, a reflector SM6, a reflector SM7, a reflector SM8, a third galvanometer M3, a reflector SM9, and a reflector SM10. The reflector P1 is located outside the beam modulation module.

[0115] The beam modulation module has four pupil conjugate surfaces, which are optically conjugate with the pupil through nine reflecting mirrors SM2-SM10. Three galvanometers (i.e., the first to third galvanometers) and a compensation mirror are placed on these four optical conjugate surfaces, simultaneously realizing three major functions: three-dimensional imaging, eye movement tracking, and real-time aberration compensation. Specifically, the first galvanometer M1 is used for lateral scanning of reflected light and OCT light; the second galvanometer M2 is used for longitudinal scanning and tracking of reflected and OCT light; the third galvanometer M3 is used for lateral tracking of reflected and OCT light; and the compensation mirror is used for real-time aberration compensation.

[0116] Further reference Figure 5 , Figure 5 This is a schematic diagram of the structure of a data acquisition and control module provided in this embodiment.

[0117] The acquisition and control module includes: a data acquisition unit, a galvanometer control unit, a compensation mirror control unit, and a computing unit;

[0118] The data acquisition unit is used to acquire the reflected light detection signal and the wavefront detection signal, and also to acquire the OCT light detection signal.

[0119] The computing unit is used to generate a two-dimensional reflection image based on the reflected light detection signal, and to generate a wavefront image based on the wavefront detection signal, and also to generate the three-dimensional retinal image based on the OCT light detection signal; the computing unit is also used to generate a first control signal based on the two-dimensional reflection image, and to generate a second control signal based on the wavefront image.

[0120] The galvanometer control unit is used to control the deflection state of the galvanometer in the beam modulation module according to the first control signal, so as to realize eye movement tracking;

[0121] The compensation mirror control unit is used to control the compensation value of the compensation mirror in the beam modulation module according to the second control signal, so as to realize real-time aberration compensation.

[0122] In this embodiment, the data acquisition unit acquires the OCT light detection signal CJ3 generated by the OCT detector, the reflected light detection signal CJ2 generated by the light detector, and the wavefront detection signal CJ1 generated by the wavefront detector in the light source detection module. These three signals are transmitted to the computing unit for signal processing to generate a three-dimensional retinal image, a two-dimensional reflection image, and a wavefront image, respectively. The galvanometer control unit controls the deflection of the first to third galvanometers in the beam modulation module based on the first control signal to achieve real-time eye movement tracking; the compensation mirror control unit controls the compensation value of the compensation mirror based on the second control signal to compensate for real-time aberrations of the human eye.

[0123] Specifically, the acquisition and control module has three input signals and four output signals. The three input signals are the OCT light detection signal CJ3, the reflected light detection signal CJ2, and the wavefront detection signal CJ1 acquired by the data acquisition unit. The four output signals are the first galvanometer control signal Q1, the second galvanometer control signal Q2, the third galvanometer control signal Q3, and the second control signal Q5 that controls the compensation value of the compensation mirror.

[0124] Specifically, during the operation of the retinal imaging device, the photodetector and OCT detector in this embodiment have the same acquisition frequency, therefore a same-frequency scanning method is used. The control logic of the device is described in detail below. (Reference) Figure 6 This is a schematic diagram of the dual-channel scanning control logic of a retinal imaging device provided in this embodiment. Specifically, the lateral scanning signal of the reflected light and the lateral scanning signal of the OCT light are superimposed on the first galvanometer control signal Q1 to drive the first galvanometer M1.

[0125] The longitudinal scanning signal of the reflected light, the longitudinal tracking signal of the reflected light, the longitudinal scanning signal of the OCT light, and the longitudinal tracking signal of the OCT light are superimposed on the second galvanometer control signal Q2 to drive the second galvanometer M2.

[0126] The lateral tracking signal of the reflected light and the lateral tracking signal of the OCT light are superimposed on the third galvanometer control signal Q3 to drive the third galvanometer M3.

[0127] It should be noted that, as Figure 2 The retinal imaging device shown has other principles and Figure 1 The principle of the retinal imaging device shown is the same, so it will not be described again here.

[0128] Optional, based on Figure 1 and Figure 2 The retinal imaging device shown, when the light source is reflected light, includes a beam modulation module comprising: three conjugate surfaces of the pupil to form three images of the human eye pupil; and a first to a third galvanometer placed on the three conjugate surfaces of the pupil.

[0129] The first galvanometer is used for lateral scanning of the reflected light.

[0130] The second galvanometer is used for longitudinal scanning and longitudinal tracking of the reflected light.

[0131] The third galvanometer is used for lateral tracking of the reflected light.

[0132] In other words, this scheme is a retinal imaging device without an OCT detection scheme, and its working principle is similar to... Figure 1 and Figure 2 The principle of the reflected light part is the same. An eyeball pupil conjugate surface can also be added to this device to place a compensating lens and achieve aberration compensation, which will not be elaborated upon here.

[0133] Example 3

[0134] This embodiment provides a retinal imaging method based on the retinal imaging device described in the above embodiments of this application. The retinal imaging method includes:

[0135] The light source detection module generates reflected light or dual-channel illumination light including reflected light and OCT light, and forms a scanning beam that is incident on the beam modulation module. The beam modulation module modulates the incident angle of the scanning beam and causes the modulated scanning beam to enter the eyeball. The feedback beam reflected by the retina passes through the beam modulation module and is incident on the light source detection module. The light source detection module generates a detection signal based on the feedback beam. The acquisition control module acquires the detection signal and controls the optical path state of the beam modulation module based on the detection signal to achieve eye movement tracking.

[0136] Furthermore, the light source detection module generates a wavefront detection signal based on a portion of the reflected light in the feedback beam, and the acquisition control module acquires the wavefront detection signal and controls the wavefront phase of the scanning beam based on the wavefront detection signal to achieve real-time aberration compensation.

[0137] It should be noted that the principle of the retinal imaging method provided in this application embodiment is the same as the principle of the retinal imaging device provided in the above embodiment of this application, and will not be repeated here.

[0138] The foregoing has provided a detailed description of a retinal imaging device and its imaging method provided by the present invention. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A retinal imaging device, characterized in that, The retinal imaging device includes: a light source detection module, a beam modulation module, and an acquisition control module; The light source detection module is used to generate dual-channel illumination light including reflected light and OCT light. The dual-channel illumination light is combined to form a scanning beam that is incident on the beam modulation module. The beam modulation module is used to modulate the incident angle of the scanning beam. The modulated scanning beam enters the eyeball, and the feedback beam reflected by the retina passes through the beam modulation module and is incident on the light source detection module. The light source detection module is also used to generate a detection signal based on the feedback beam; The acquisition and control module is used to acquire the detection signal and control the optical path state of the beam modulation module based on the detection signal to achieve eye movement tracking; The beam modulation module includes: four pupil conjugate surfaces to form four images of the human eye pupil; and first to fourth galvanometers are respectively placed on the four pupil conjugate surfaces. The first galvanometer is used for lateral scanning of the reflected light; The second galvanometer is used for lateral scanning of the OCT light; Among them, the working frequency of OCT light transverse scanning is different from that of reflected light transverse scanning; The third galvanometer is used for longitudinal scanning and longitudinal tracking of the reflected light and the OCT light; The fourth galvanometer is used for lateral tracking of the reflected light and the OCT light; The beam modulation module also includes an eyeball pupil conjugate surface for placing a compensation mirror; the compensation mirror is used for real-time aberration compensation.

2. The retinal imaging device according to claim 1, characterized in that, The light source detection module includes: a light source and a photodetector; When the light source generates dual-channel illumination light, the light source detection module also includes an OCT detector; The photodetector is used to generate a reflected light detection signal based on the reflected light in the feedback beam; the OCT detector is used to generate an OCT light detection signal based on the OCT light in the feedback beam.

3. A retinal imaging device according to claim 2, characterized in that, The acquisition and control module includes: a data acquisition unit, a galvanometer control unit, and a computing unit; The data acquisition unit is used to acquire the reflected light detection signal, or simultaneously acquire the OCT light detection signal; The computing unit is used to generate a two-dimensional reflection image based on the reflected light detection signal, or simultaneously generate the three-dimensional retinal image based on the OCT light detection signal; the computing unit is also used to generate a first control signal based on the two-dimensional reflection image; The galvanometer control unit is used to control the deflection state of the galvanometer in the beam modulation module according to the first control signal, so as to realize eye movement tracking.

4. A retinal imaging device according to claim 2, characterized in that, The light source detection module further includes a wavefront detector, which is used to generate a wavefront detection signal based on a portion of the reflected light in the feedback beam.

5. A retinal imaging device according to claim 4, characterized in that, The acquisition and control module includes: a data acquisition unit, a galvanometer control unit, a compensation mirror control unit, and a computing unit; The data acquisition unit is used to acquire the reflected light detection signal and the wavefront detection signal, or simultaneously acquire the OCT light detection signal; The computing unit is used to generate a two-dimensional reflection image based on the reflected light detection signal, and to generate a wavefront image based on the wavefront detection signal, or simultaneously generate the three-dimensional retinal image based on the OCT light detection signal; the computing unit is also used to generate a first control signal based on the two-dimensional reflection image, and to generate a second control signal based on the wavefront image. The galvanometer control unit is used to control the deflection state of the galvanometer in the beam modulation module according to the first control signal to achieve eye movement tracking; the compensation mirror control unit is used to control the compensation value of the compensation mirror in the beam modulation module according to the second control signal to achieve real-time aberration compensation.

6. A retinal imaging device according to claim 3 or 5, characterized in that, The reflected light includes light of multiple different wavelengths, and the computing unit generates a colored two-dimensional reflection image based on the reflected light detection signal.

7. A retinal imaging method, characterized in that, Based on the retinal imaging apparatus according to any one of claims 1-5, the retinal imaging method includes: The light source detection module generates dual-channel illumination light, including reflected light and OCT light, and forms a scanning beam that is incident on the beam modulation module. The beam modulation module modulates the incident angle of the scanning beam and causes the modulated scanning beam to enter the eyeball. The feedback beam, after being reflected by the retina, passes through the beam modulation module and is incident on the light source detection module. The light source detection module generates a detection signal based on the feedback beam. The acquisition control module acquires the detection signal and controls the optical path state of the beam modulation module based on the detection signal to achieve eye movement tracking.

8. A retinal imaging method according to claim 7, characterized in that, The light source detection module also generates a wavefront detection signal based on a portion of the reflected light in the feedback beam. The acquisition control module acquires the wavefront detection signal and controls the wavefront phase of the scanning beam based on the wavefront detection signal to achieve real-time aberration compensation.

Images