A handheld full-field OCT device for wide-field imaging

Abstract

The application belongs to the technical field of full-eye imaging medical equipment, and particularly relates to a handheld full-eye OCT device for realizing wide-area imaging, which comprises an imaging system, a control system, a reference arm module and a sample arm module; the sample arm module comprises a galvanometer module and a switching module arranged in sequence on an output light path of a fiber interference module; the switching module comprises a third achromatic doublet lens group, a flip mirror structure and a fourth achromatic doublet lens group arranged in sequence on an output light path of the galvanometer module, and the third and fourth achromatic doublet lens groups form a telescope system; the switching module switches different imaging positions through the flip mirror structure. Compared with the prior art, the application solves the single imaging of the prior art which is mainly used for the anterior segment or posterior segment of the eye, and the field of view is small, it is difficult to fully cover the entire posterior segment of the eye, and the traditional fundus photography technology also has the problem of limited field of view; the scheme can realize wide-angle imaging of a large field of view in the posterior segment of the eye while switching the imaging positions of the anterior segment and the posterior segment.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of full-eye imaging medical devices, and particularly relates to a handheld full-eye OCT device for realizing wide-area imaging. BACKGROUND

[0002] The eye is one of the most valuable organs of the human body, and plays an indispensable role in life. Similarly, eye diseases and vision loss are serious problems. Image examination involving the full eye is an important means of ophthalmic diagnosis.

[0003] Optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) have been rapidly developed into indispensable diagnostic tools in ophthalmology in recent years as the gold standard for ophthalmic disease diagnosis, with the advantages of in vivo, non-invasive, real-time, high-resolution and three-dimensional tomographic imaging. Among them, handheld OCT has been widely used in ophthalmology and other medical fields due to its portability and flexibility of operation.

[0004] Existing handheld OCT devices are mostly used for imaging of the anterior segment (such as the cornea and the anterior chamber) or the posterior segment (such as the retina and the choroid) of the eye, but most systems are difficult to achieve wide-angle scanning and comprehensive coverage of the anterior and posterior segments of the eye. The limited field of view of the traditional handheld OCT device makes it difficult to provide comprehensive information on the structure and function of the eye, which limits early disease diagnosis and treatment effect evaluation.

[0005] As disclosed in CN103815868A, a full-eye optical coherence tomography instrument includes a swept source, a fiber optic polarizer, first and second optical circulators, first and second broadband polarization beam splitting prisms in a sample arm module, an anterior segment scanning imaging light path and a fundus scanning imaging light path, a third broadband polarization beam splitting prism and two reference mirrors in a reference arm module, fourth and fifth broadband polarization beam splitting prisms, second and third polarization maintaining optical couplers, first and second balanced detectors at a detection end, and a function generator card, a data acquisition card, and a computer. However, 1) the system uses a polarization beam splitting prism, which increases the difficulty of system debugging and operation; 2) in the beam splitting system, light is split into different polarization components, which results in a decrease in light intensity in each polarization direction (usually the light intensity in each polarization direction is halved); 3) the beam splitting system needs to process polarization-dependent signals, and additional data processing is required to analyze light in different polarization states, which increases the computational burden of the system and reduces the speed of signal acquisition and processing.

[0006] An eye anterior and posterior segment integrated optical coherence tomography / angiography imaging system disclosed in CN113520298A includes a swept laser light source, a fiber coupler, a circulator, a polarization controller, a control system, a reference arm module, and a sample arm module. The sample arm module includes an anterior segment structure / function imaging system and a posterior segment structure / function imaging system, which can realize OCT / OCTA imaging of different parts of the whole eye, and switch different imaging parts through a flip mirror device. Although the anterior segment and posterior segment OCT systems of this scheme can provide structure and function imaging, they cannot simultaneously realize wide-area imaging of the anterior and posterior segments, and two mirrors need to be flipped at the sample arm, increasing the operation difficulty and making it difficult to ensure accuracy.

[0007] Therefore, it is necessary to provide a full-eye OCT device capable of realizing wide-area imaging. SUMMARY

[0008] The purpose of the present application is to solve at least one of the above problems by providing a handheld full-eye OCT device capable of realizing wide-area imaging. The present application solves the problem of single imaging of the anterior segment or posterior segment in the prior art, and the small field of view makes it difficult to cover the entire posterior segment. The traditional fundus photography technology also has the problem of limited field of view, which makes it difficult to provide comprehensive eye structure and function information, especially the requirement of wide-angle scanning in the posterior segment, which limits early disease diagnosis and treatment effect evaluation. The present application realizes wide-angle imaging in the posterior segment while changing the imaging position of the anterior and posterior segments of the OCT / OCTA imaging system at any time through simple switching. In addition to solving the problem of vignetting artifacts generated during imaging, the present application also has the advantage of convenient system operation.

[0009] The purpose of the present application is achieved by the following technical solutions:

[0010] A handheld full-eye OCT device capable of realizing wide-area imaging is used to implement full-eye OCT and OCTA on a measured eyeball, and includes an imaging system, a control system, a reference arm module, and a sample arm module.

[0011] The imaging system includes a swept laser light source, a fiber interference module, and a photoelectric balance detector. The fiber interference module is arranged on the output light path of the swept laser light source, and the fiber interference module has multiple output light paths. The photoelectric balance detector, the reference arm module, and the sample arm module are arranged on different output light paths of the fiber interference module.

[0012] The sample arm module comprises a galvanometer module and a switching module arranged in sequence on the output light path of the optical fiber interference module; the switching module comprises a third achromatic doublet lens group, a flip mirror structure and a fourth achromatic doublet lens group arranged in sequence on the output light path of the galvanometer module, wherein the third achromatic doublet lens group and the fourth achromatic doublet lens group constitute a telescope system for implementing wide-angle scanning on the ocular posterior segment; the switching module switches different imaging positions of the eye to be tested through the flip mirror structure.

[0013] The eye to be tested is located on the output light path of the sample arm module.

[0014] The control system is electrically connected with the swept laser light source, the photoelectric balance detector and the galvanometer module respectively.

[0015] Preferably, the flip mirror structure comprises a sixth mirror, a seventh mirror, an eighth mirror, a ninth mirror and an achromatic doublet lens arranged in sequence on the output light path of the third achromatic doublet lens group, and the sixth mirror is also on the output light path of the achromatic doublet lens.

[0016] The sixth mirror reflects the output light path of the third achromatic doublet lens group to the fourth achromatic doublet lens group or the seventh mirror, thereby switching different imaging positions of the eye to be tested.

[0017] Preferably, when the sixth mirror reflects the output light path of the third achromatic doublet lens group to the fourth achromatic doublet lens group, it is an ocular posterior segment imaging mode, and the distance between the lenses and the focal length of the lenses are matched.

[0018] When the sixth mirror reflects the output light path of the third achromatic doublet lens group to the seventh mirror, it is an ocular anterior segment imaging mode, and the distance between the lenses is equal to the sum of the focal lengths of the lenses.

[0019] Preferably, the focal length f1 of the third achromatic doublet lens group is greater than the focal length f3 of the fourth achromatic doublet lens group.

[0020] Preferably, the galvanometer module comprises a first galvanometer, a first achromatic doublet lens group, a second achromatic doublet lens group and a second galvanometer arranged in sequence on the output light path of the optical fiber interference module.

[0021] The control system is electrically connected with the first galvanometer and the second galvanometer respectively.

[0022] Preferably, the first achromatic doublet lens group and the second achromatic doublet lens group constitute a 4F system.

[0023] Preferably, the sample arm module further comprises a second beam expander and an electrically adjustable focusing lens.

[0024] The second beam expander collimator and the electric focusing lens are sequentially arranged on the light path between the fiber interference module and the galvanometer module.

[0025] Preferably, the reference arm module comprises a first beam expander collimator, a first mirror, a second mirror, a third mirror, a fourth mirror and a fifth mirror sequentially arranged on the output light path of the fiber interference module.

[0026] The reference arm module satisfies that the reflected light path coincides with the incident light path.

[0027] Preferably, the fiber interference module comprises a first fiber coupler, a second fiber coupler, a first circulator, a second circulator, a first polarization controller and a second polarization controller.

[0028] The first circulator is connected with the first fiber coupler, the second fiber coupler and the first polarization controller through optical fibers respectively; and the reference arm module is located on the output light path of the first polarization controller.

[0029] The second circulator is connected with the first fiber coupler, the second fiber coupler and the second polarization controller through optical fibers respectively; and the sample arm module is located on the output light path of the second polarization controller.

[0030] The second fiber coupler is connected with the photoelectric balance detector through an optical fiber.

[0031] Preferably, the control system comprises a high-speed acquisition card and a signal acquisition card.

[0032] The high-speed acquisition card is electrically connected with the frequency-sweeping laser light source, the photoelectric balance detector and the signal acquisition card respectively.

[0033] The signal acquisition card is electrically connected with the galvanometer module.

[0034] Compared with the prior art, the present application has the following beneficial effects:

[0035] In the present application, considering the needs of imaging the anterior segment and the wide-angle retina and choroid, the optical path is designed to pass through optical conversion so that the sample light is focused in front of the lens and at the back end of the retina respectively. In order to achieve the requirement of wide-angle scanning in the posterior segment of the eye, a telescope system is used in the sample arm module to make the scanning angle larger, and a 4F system is used in the scanning module to eliminate the vignetting artifact, and the device is simple and convenient to operate. Moreover, the non-splitting system in the present application concentrates the intensity of all light on one detection channel, which can obtain higher signal intensity and better signal-to-noise ratio.

[0036] The structure of the switching module for switching of the anterior segment imaging mode is annular arrangement, which enhances the compactness of the structure, so that it can better realize handheld. The scheme can also realize wide field imaging of the anterior and posterior segments at the same time, and only needs to turn over a mirror at the sample arm, so that the structure is simpler, the operation is more convenient, and the precision is higher.

[0037] The optical path design of the sample arm part in the scheme reduces the heavy structure in the traditional optical device by using simplified optical elements such as liquid lenses and light collimation mirrors. The liquid lens can realize focusing through electronic control without large mechanical structure, which greatly reduces the overall weight of the sample arm and makes it suitable for handheld operation. Therefore, the volume and weight of the handheld end (sample arm module) in the device of the present application are small, and finally the handheld OCT device can be constructed.

[0038] In summary, the scheme can realize handheld and wide field imaging at the same time, while the prior art cannot realize handheld and wide field imaging at the same time. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 It is a structural schematic diagram of a handheld full-eye OCT device;

[0040] Figure 2 It is a structural schematic diagram of a galvanometer module;

[0041] Figure 3 It is a structural and optical path schematic diagram of the switching module when imaging the anterior segment;

[0042] Figure 4 It is an optical path schematic diagram of the switching module when imaging the posterior segment;

[0043] Figure 5 It is a structural and optical path schematic diagram of the switching module when imaging the posterior segment;

[0044] Figure 6 It is a point column diagram of the switching module when imaging the posterior segment;

[0045] In the figure:

[0046] 1, swept laser light source;

[0047] 2, first fiber coupler;

[0048] 3, second fiber coupler;

[0049] 4, first circulator;

[0050] 5, second circulator;

[0051] 6, first polarization controller;

[0052] 7, second polarization controller;

[0053] 8. An optical balanced detector;

[0054] 9. A high-speed acquisition card;

[0055] 10. A signal acquisition card;

[0056] 11. A first mirror:

[0057] 12. A second mirror;

[0058] 13. A third mirror;

[0059] 14. A fourth mirror;

[0060] 15. A fifth mirror;

[0061] 16. A sixth mirror;

[0062] A. An optical fiber interference module;

[0063] B. A reference arm module;

[0064] C. A sample arm module;

[0065] D. A switching module;

[0066] E. A galvanometer module

[0067] L1. A first beam expander collimator;

[0068] L2. A second beam expander collimator;

[0069] L3. A motorized focus lens;

[0070] L4. A first achromatic doublet lens group;

[0071] L5. A second achromatic doublet lens group;

[0072] L6. A third achromatic doublet lens group;

[0073] L7. An achromatic doublet lens;

[0074] L8. A fourth achromatic doublet lens group;

[0075] G1. A first galvanometer;

[0076] G2. A second galvanometer. DETAILED DESCRIPTION

[0077] The present application will be described in detail below with reference to the drawings and specific embodiments.

[0078] EMBODIMENTS

[0079] A handheld full-eye OCT device for wide-field imaging, as shown inFigures 1-6 The imaging system, the control system, the reference arm module B and the sample arm module C are used for implementing the whole eye OCT and OCTA on the eye to be measured.

[0080] The imaging system comprises a swept laser light source 1, a fiber interference module A and a photoelectric balance detector 8; the fiber interference module A is arranged on an output light path of the swept laser light source 1, and the fiber interference module A has a plurality of output light paths; the photoelectric balance detector 8, the reference arm module B and the sample arm module C are arranged on different output light paths of the fiber interference module A respectively.

[0081] The sample arm module B comprises a galvanometer module E and a switching module D arranged on the output light path of the fiber interference module A in sequence; the switching module D comprises a third achromatic doublet lens group L5, a flip mirror structure and a fourth achromatic doublet lens group L8 arranged on the output light path of the galvanometer module E in sequence, wherein the third achromatic doublet lens group L5 and the fourth achromatic doublet lens group L8 constitute a telescope system for implementing wide-angle scanning on the posterior segment of the eye; the switching module D switches different imaging parts of the eye to be measured through the flip mirror structure.

[0082] The eye to be measured is located on the output light path of the sample arm module C.

[0083] The control system is electrically connected with the swept laser light source 1, the photoelectric balance detector 8 and the galvanometer module E respectively.

[0084] More specifically, in the embodiment, the imaging system comprises a swept laser light source 1, a fiber interference module A (specifically comprising a first fiber coupler 2, a second fiber coupler 3, a first loop mirror 4, a second loop mirror 5, a first polarization controller 6, a second polarization controller 7), a photoelectric balance detector 8.

[0085] Reference Figure 1 The embodiment provides a handheld whole eye OCT device capable of realizing wide-area imaging, comprising an imaging system, a control system, a reference arm module B and a sample arm module C.

[0086] In the embodiment, the imaging system specifically comprises a swept laser light source 1, a fiber interference module A (specifically comprising a first fiber coupler 2, a second fiber coupler 3, a first loop mirror 4, a second loop mirror 5, a first polarization controller 6, a second polarization controller 7), a photoelectric balance detector 8.

[0087] In the optical fiber interference module A, the laser from the swept laser light source 1 passes through the first optical fiber coupler 2, and then provides incident light to the reference arm module B through the first circulator 4 and the first polarization controller 6, and provides incident light to the sample arm module C through the second circulator 5 and the second polarization controller 7. The reference light reflected back by the reference arm module B enters the second optical fiber coupler 3 through the first polarization controller 6 and the first circulator 4; the light reflected back by the sample arm module C enters the second optical fiber coupler 3 through the second polarization controller 7 and the second circulator 5. Interference occurs in the second optical fiber coupler 3 to generate interference light, which is detected by the photoelectric balance detector 8, processed by the control system, and then the optical coherence tomography image of the human eye is obtained.

[0088] In the embodiment, the control system includes a high-speed acquisition card 9 and a signal acquisition card 10, the electrical signal output end of the photoelectric balance detector 8 is connected to the high-speed acquisition card 9, and the output end of the high-speed acquisition card 9 is connected to the digital signal acquisition card 10; the output end of the swept laser light source 1 is connected to the high-speed acquisition card 9; the digital signal acquisition card 10 is used to process signals to obtain OCT / OCTA images.

[0089] In the embodiment, the reference arm module B includes a first beam expander collimator L1, a first mirror 11, a second mirror 12, a third mirror 13, a fourth mirror 14, and a fifth mirror 15. The optical path matching of the anterior and posterior segments of the eye is realized by flipping the first mirror 11 and the fourth mirror 14 (which are configured with a flipping frame).

[0090] In the embodiment, the sample arm module C includes a second beam expander collimator L2, an electrically tunable lens L3, a galvanometer module E, and a switching module D.

[0091] Reference Figure 2 The galvanometer module E includes a first galvanometer G1, a first achromatic doublet lens group L4, a second achromatic doublet lens group L5, and a second galvanometer G2, wherein the first achromatic doublet lens group L4 and the second achromatic doublet lens group L5 form a 4F system, which can eliminate the scanning focal point difference on the pupil and eliminate the axis-dependent vignetting artifact. In addition, the galvanometer module E is connected to the control system through electrical connection, and the control system transmits signals to the galvanometer module E to control the movement of the galvanometer, so as to change the scanning path and angle, thereby realizing the scanning of different imaging areas. Specifically, the first galvanometer G1 and the second galvanometer G2 in the galvanometer module E are respectively responsible for the deflection of the light beams in different directions, and the control system precisely controls the rotation angles of the two galvanometers by adjusting the electrical signals, so as to realize the precise control of the scanning light path.

[0092] The switching module D includes a third achromatic doublet lens group L6, a sixth mirror 16, a seventh mirror 17, an eighth mirror 18, a ninth mirror 19, an achromatic doublet lens L7, and a fourth achromatic doublet lens group L8.

[0093] The components of the switching module D constitute an anterior segment structure / function imaging subsystem (for an anterior segment imaging mode, imaging the anterior segment of the eye to be measured) and a posterior segment structure / function imaging subsystem (for a posterior segment imaging mode, imaging the posterior segment of the eye to be measured), which can realize OCT / OCTA imaging of different parts of the eye. Moreover, the switching module D switches different imaging parts through a flip mirror device, which is composed of mirrors (the sixth mirror 16, the seventh mirror 17, the eighth mirror 18, the ninth mirror 19, and the achromatic doublet lens L7) disposed between the third achromatic doublet lens group L6 and the fourth achromatic doublet lens group L8, and can directly switch the anterior segment imaging mode and the posterior segment imaging mode.

[0094] Reference Figure 3 When the anterior segment structure / function imaging subsystem is in the anterior segment imaging mode, the optical path thereof sequentially passes through the third achromatic doublet lens group L6, the seventh mirror 17, the eighth mirror 18, the ninth mirror 19, the achromatic doublet lens L7, and the fourth achromatic doublet lens group L8; the optical path of the reference arm module B corresponding to the anterior segment structure / function imaging subsystem sequentially passes through the first beam expander and collimator L1, the first mirror 11, the second mirror 12, the third mirror 13, the fourth mirror 14, and the fifth mirror 15.

[0095] The third achromatic doublet lens group L6, the seventh mirror 17, the eighth mirror 18, the ninth mirror 19, the achromatic doublet lens L7, and the fourth achromatic doublet lens group L8 are arranged to satisfy that the light from the signal light input arm sequentially passes through the third achromatic doublet lens group L6, the seventh mirror 17, the eighth mirror 18, the ninth mirror 19, the achromatic doublet lens L7, and the fourth achromatic doublet lens group L8, and is focused on the anterior segment of the eye to be measured through the fourth achromatic doublet lens group L8. The first beam expander and collimator L1, the first mirror 11, the second mirror 12, the third mirror 13, the fourth mirror 14, and the fifth mirror 15 are arranged to satisfy that the light from the first beam expander and collimator L1 sequentially passes through the first mirror 11, the second mirror 12, the third mirror 13, and the fourth mirror 14, reaches the fifth mirror 15, and is reflected back to the original path.

[0096] Wherein, for the anterior segment structure / function imaging subsystem, the light from the galvanometer module E is a parallel light beam, which enters the third achromatic doublet lens group L6 for focusing, is reflected by the seventh mirror 17 with a 45° angle, is reflected by the eighth mirror 18 with a 45° angle, is reflected by the ninth mirror 19 with a 45° angle again, and is reflected into the achromatic doublet lens L7 again to become parallel light again. The parallel light is converged by the fourth achromatic doublet lens group L8 to the anterior segment of the eye to be measured and is focused.

[0097] In the optical path of the anterior segment structure / function imaging subsystem, the optical path distance is matched with the reference optical path distance, and the distance between the lenses is equal to the sum of the focal lengths of the lenses. Thus, after the signal light is focused by the third achromatic doublet lens group L6 in the anterior segment structure / function imaging subsystem, the light is reflected by the seventh mirror 17, the eighth mirror 18, and the ninth mirror 19, and then enters the achromatic doublet lens L7. Because the optical path distance is equal to the sum of the focal lengths of the lenses, the focused light is diverged to become parallel light again, and then is focused by the fourth achromatic doublet lens group L8 on the anterior segment. Here, the fourth achromatic doublet lens group L8 acts as a posterior segment lens.

[0098] The optical path of the posterior segment structure / function imaging subsystem (for the posterior segment imaging mode, imaging the posterior segment of the eye to be measured) passes through the third achromatic doublet lens group L6, the sixth mirror 16, and the fourth achromatic doublet lens group L8 in sequence. The focal length f1 of the third achromatic doublet lens group L6 is greater than the focal length f3 of the fourth achromatic doublet lens group (f1 > f3). The optical path of the posterior segment structure / function imaging subsystem corresponding to the reference arm module B passes through the first beam expander collimator L1 to the fifth mirror 15.

[0099] Reference Figure 4 The third achromatic doublet lens group L6 and the fourth achromatic doublet lens group L8 form a telescope system, which enlarges the scanning angle of the galvanometer module E, and realizes wide-angle imaging of the posterior segment.

[0100] Reference Figure 5 The third achromatic doublet lens group L6, the sixth mirror 16, and the fourth achromatic doublet lens group L8 are arranged to satisfy that the light from the galvanometer module E passes through the third achromatic doublet lens group L6, the sixth mirror 16, and the fourth achromatic doublet lens group L8 in sequence. The first beam expander collimator L1 and the fifth mirror 15 are arranged to satisfy that the light from the first beam expander collimator L1 reaches the fifth mirror 15 and is reflected back to the original path.

[0101] Wherein, for the eye posterior segment structure / function imaging subsystem, the light from the galvanometer module E is parallel light, which enters the third achromatic doublet lens group L6 for focusing, and after the focusing, the light is reflected by the sixth mirror 16 at an angle of 45° and then enters the fourth achromatic doublet lens group L8, and after the focusing and divergence by the third achromatic doublet lens group L6 and the fourth achromatic doublet lens group L8, the light becomes parallel light again, wherein the distance between the third achromatic doublet lens group L6 and the fourth achromatic doublet lens group L8 is equal to the sum of the focal lengths of the two lenses, and the parallel light enters the lens of the eye to be measured, and the lens focuses the incident parallel light to the retina for imaging.

[0102] In the optical path of the eye posterior segment structure / function imaging subsystem, the third achromatic doublet lens group L6 focuses the signal light, which is then transmitted through the sixth mirror 16 and diverged by the fourth achromatic doublet lens group L8 into parallel light to enter the eye, and focused by the lens to the eye posterior segment for imaging.

[0103] Reference Figure 1 The sample arm module C includes a second beam expander collimator L2, an electrically driven focusing lens L3, a galvanometer module E and a switching module D, the second beam expander collimator L2 is used to receive the laser light source after being processed by the optical fiber interference module A, the electrically driven focusing lens L3 is used to transmit the light beam to the first galvanometer G1, the first galvanometer G1 is used to reflect and deflect the light beam to form a parallel light beam, which enters the 4F system composed of the first achromatic doublet lens group L4 and the second achromatic doublet lens group L5, and the light transmitted by the 4F system is reflected and deflected by the second galvanometer G2 to the anterior segment structure / function imaging subsystem or the posterior segment structure / function imaging subsystem of the switching module D.

[0104] In the optical path of the eye posterior segment structure / function imaging subsystem, the optical path is matched with the reference arm optical path (the optical path difference is kept within the coherence length of the light source), and the distance between the lenses and the focal length are matched (the distance between the lenses is the sum of the focal lengths of the lenses).

[0105] In this embodiment, considering the need for imaging of the anterior segment and the wide-angle retina and choroid, the optical path is designed to be converted by optics so that the sample light is focused in front of the lens and at the back end of the retina, respectively. In order to achieve the requirement of wide-angle scanning in the eye posterior segment, a telescope system is used at the sample arm module C to increase the scanning angle, and a 4F system is used in the galvanometer module E to eliminate vignetting artifacts, and the device is simple and easy to operate.

[0106] In the embodiment, the first achromatic doublet lens group L4, the second achromatic doublet lens group L5, the third achromatic doublet lens group L6, and the fourth achromatic doublet lens group L8 are lens groups combined by two achromatic doublet lenses, and the achromatic doublet lens L7 is an optical structure combined by two single lenses.

[0107] In summary, the scheme of the embodiment has the following advantages when used:

[0108] Anterior segment imaging mode: After receiving the imaging scanning instruction, the swept frequency laser light source 1 emits broadband pulsed laser light into the first optical fiber coupler 2. Then, part of the light enters the first circulator 4, and then passes through the first polarization controller 6, and then passes through the first expansion collimator L1, the first mirror 11, the second mirror 12, the third mirror 13, the fourth mirror 14, the fifth mirror 15, and returns to the first circulator 4 by the reflection of the fifth mirror 15, and then enters the second optical fiber coupler 3. Another part of the light enters the second circulator 5, and then passes through the second polarization controller 7, and then passes through the second expansion collimator L2, the electric focusing lens L3, the first galvanometer G1, the first achromatic doublet lens group L4, the second achromatic doublet lens group L5, the second galvanometer G2, and then the parallel light beam enters the third achromatic doublet lens group L6 for focusing. After being reflected by the 45°-angled seventh mirror 17 on the focusing light path, and then reflected by the 45°-angled eighth mirror 18 and then reflected by the 45°-angled ninth mirror 19 again, the parallel light is re-divergent into parallel light by the achromatic doublet lens L7, and then the parallel light is focused on the anterior segment of the eye to be measured by the fourth achromatic doublet lens group L8. The collected light signal returns to the second circulator 5, and then enters the second optical fiber coupler 3. Interference occurs in the second optical fiber coupler 3 to produce interference light, which is detected by the photoelectric balance detector 8, and then processed by the control system to obtain the optical coherence tomography of the human eye.

[0109] The imaging mode of the posterior segment of the eye: after receiving the imaging scanning instruction, the swept laser light source 1 emits broadband pulsed laser light into the first optical fiber coupler 2. Then, part of the light enters the first circulator 4, then passes through the first polarization controller 6, and then passes through the first beam expander collimator L1 to the fifth mirror 15, and is reflected by the fifth mirror 15 to return to the first circulator 4, and then enters the second optical fiber coupler 3. Another part of the light enters the second circulator 5, then passes through the second polarization controller 7, and then passes through the second beam expander collimator L2, the electric focusing lens L3, the first galvanometer G1, the first achromatic doublet lens group L4, the second achromatic doublet lens group L5, and the second galvanometer G2, and then the parallel light beam enters the third achromatic doublet lens group L6 for focusing. After focusing, the light is reflected by the sixth mirror 16 at an angle of 45°, directly enters the fourth achromatic doublet lens group L8, and is focused and dispersed by the third achromatic doublet lens group L6 and the fourth achromatic doublet lens group L8 to become parallel light again. The distance between the third achromatic doublet lens group L6 and the fourth achromatic doublet lens group L8 is equal to the sum of the focal lengths of the two lenses. The parallel light beam enters the lens of the eye to be measured, and the lens focuses the incident parallel light on the retina to form an image. The collected light signal returns to the second circulator 5 and then enters the second optical fiber coupler 3. Interference occurs in the second optical fiber coupler 3 to produce interference light. After the interference light is detected by the photoelectric balance detector 8 and processed by the control system, the optical coherence tomography of the human eye is obtained.

[0110] Reference Figure 6 , Figure 6 The point spread function of the posterior segment structure / function imaging system is shown in the figure. The RMS radius of each field of view is less than the diffraction limit Airy disk radius 23.43 μm, which indicates that the image quality of the device is high.

[0111] In this embodiment, the light source of the OCT / OCTA provides incident light to the sample arm module C and the reference arm module B through the optical fiber coupler, respectively. The light incident to the sample arm module C is incident to the anterior segment or the posterior segment of the eye and is reflected. The returned light passes through the sample arm module C and interferes with the light returned from the reference arm module B in the optical fiber coupler to produce interference light. The interference light is input into the photoelectric balance detector for processing, and then processed by the computer system to obtain the OCT / OCTA tomography of the human eye.

[0112] The present application aims at the problem of small imaging field of view of the existing handheld OCT device, and wide-angle imaging is realized in the posterior segment of the eye by using a telescope system in the posterior segment structure / function imaging subsystem. Meanwhile, the volume and weight of the handheld end (sample arm module C) of the system are small, and finally the construction of the handheld OCT device can be realized. The device solves the problem of vignetting artifact in the imaging process by using a 4F system, and realizes high-quality imaging. The device can realize wide-angle posterior segment structure / blood flow imaging, and handheld full-eye imaging device, which has important significance for real-time imaging research of eye diseases.

[0113] The above description of the embodiments is for the purpose of enabling a person of ordinary skill in the art to understand and use the application. Those skilled in the art can easily make various modifications to the embodiments, and apply the general principles described herein to other embodiments without creative labor. Therefore, the present application is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present application without departing from the scope of the present application should be within the protection scope of the present application.

Claims

1. A handheld whole-eye OCT device for achieving wide-area imaging, used to perform whole-eye OCT and OCTA on the eye to be tested, characterized in that, The imaging system, the control system, the reference arm module (B) and the sample arm module (C) are included. The imaging system comprises a swept laser light source (1), a fiber interference module (A) and a photoelectric balance detector (8); the fiber interference module (A) is arranged on the output light path of the swept laser light source (1), and the fiber interference module (A) has a plurality of output light paths; the photoelectric balance detector (8), the reference arm module (B) and the sample arm module (C) are arranged on different output light paths of the fiber interference module (A) respectively. The sample arm module (C) comprises a galvanometer module (E) and a switching module (D) arranged on the output light path of the fiber interference module (A) in sequence; the switching module (D) comprises a third achromatic doublet lens group (L6), a flip mirror structure and a fourth achromatic doublet lens group (L8) arranged on the output light path of the galvanometer module (E) in sequence, wherein the third achromatic doublet lens group (L6) and the fourth achromatic doublet lens group (L8) constitute a telescope system for implementing wide-angle scanning on the posterior segment of the eye; the switching module (D) switches different imaging parts of the eye to be measured through the flip mirror structure. The eye to be measured is located on the output light path of the sample arm module (C). The control system is electrically connected with the swept laser light source (1), the photoelectric balance detector (8) and the galvanometer module (E) respectively. 2.The handheld full-field OCT device for wide-field imaging of claim 1, wherein, The flip mirror structure comprises a sixth mirror (16), a seventh mirror (17), an eighth mirror (18), a ninth mirror (19) and an achromatic doublet lens (L7) arranged on the output light path of the third achromatic doublet lens group (L6) in sequence; the sixth mirror (16) is also on the output light path of the achromatic doublet lens (L7). The sixth mirror (16) reflects the output light path of the third achromatic doublet lens group (L6) to the fourth achromatic doublet lens group (L8) or the seventh mirror (17), so as to switch different imaging parts of the eye to be measured. 3.The hand-held full-field OCT device for wide-field imaging of claim 2, wherein, When the sixth mirror (16) reflects the output light path of the third achromatic doublet lens group (L6) to the fourth achromatic doublet lens group (L8), it is the posterior segment imaging mode, and the distance between the lenses and the focal length of the lenses are matched. When the sixth mirror (16) reflects the output light path of the third achromatic doublet lens group (L6) to the seventh mirror (17), it is the anterior segment imaging mode, and the distance between the lenses is equal to the sum of the focal lengths of the lenses.

4. The handheld, full-field OCT device for wide-field imaging of claim 1, wherein, The focal length f1 of the third achromatic doublet lens group (L6) is greater than the focal length f3 of the fourth achromatic doublet lens group (L8).

5. The handheld, full-field OCT device for wide-field imaging according to claim 1, wherein, The galvanometer module (E) comprises a first galvanometer (G1), a first achromatic doublet lens group (L4), a second achromatic doublet lens group (L5) and a second galvanometer (G2) arranged on the output light path of the fiber interference module (A) in sequence. The control system is electrically connected with the first galvanometer (G1) and the second galvanometer (G2) respectively.

6. The handheld, full-field OCT device for wide-field imaging according to claim 5, wherein, The first achromatic doublet lens group (L4) and the second achromatic doublet lens group (L5) form a 4F system.

7. The handheld, full-field OCT device for wide-field imaging according to claim 1, wherein, The sample arm module (C) further comprises a second beam expander collimator (L2) and a motorized focusing lens (L3). The second beam expander collimator (L2) and the motorized focusing lens (L3) are sequentially arranged on the optical path between the fiber interference module (A) and the galvanometer module (E).

8. The handheld, full-field OCT device for wide-field imaging of claim 1, wherein, The reference arm module (B) comprises a first beam expander collimator (L1), a first mirror (11), a second mirror (12), a third mirror (13), a fourth mirror (14) and a fifth mirror (15) which are sequentially arranged on the output optical path of the fiber interference module (A). The reference arm module (B) satisfies that the reflected light path coincides with the incident light path.

9. The handheld, full-field OCT device for wide-field imaging of claim 1, wherein, The fiber interference module (A) comprises a first fiber coupler (2), a second fiber coupler (3), a first circulator (4), a second circulator (5), a first polarization controller (6) and a second polarization controller (7). The first circulator (4) is connected with the first fiber coupler (2), the second fiber coupler (3) and the first polarization controller (6) through optical fibers respectively; and the reference arm module (B) is located on the output optical path of the first polarization controller (6). The second circulator (5) is connected with the first fiber coupler (2), the second fiber coupler (3) and the second polarization controller (7) through optical fibers respectively; and the sample arm module (C) is located on the output optical path of the second polarization controller (7). The second fiber coupler (3) is connected with a photoelectric balance detector (8) through an optical fiber.

10. The handheld, full-field OCT device for wide-field imaging of claim 1, wherein, The control system comprises a high-speed acquisition card (9) and a signal acquisition card (10). The high-speed acquisition card (9) is electrically connected with the frequency-sweeping laser light source (1), the photoelectric balance detector (8) and the signal acquisition card (10) respectively. The signal acquisition card (10) is electrically connected with the galvanometer module (E).

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