An OCT system with simultaneous depth perception and 3D imaging

Abstract

The present invention discloses an OCT system capable of simultaneously performing A-scan depth perception and 3D imaging, relating to the field of optical imaging technology. The system utilizes a single light source within the same system and a single acquisition card to simultaneously perform A-scan and 3D scanning OCT imaging. This system can simultaneously perform A-scan-based relative tissue depth perception of surgical instruments and 3D high-resolution structural imaging. The depth perception function is integrated with the surgical instrument via a single-mode fiber probe, and the 3D high-resolution structural imaging can be integrated with a microscope or used independently for tissue structural imaging. The system simultaneously performs quantitative fundus imaging and 3D depth perception of the subretinal surgical mechanism. Therefore, it can achieve both scanning optical coherence tomography imaging of the fundus retina and obtain depth-direction position perception information of the surgical instrument (needle). Combined with the projection plane provided by the microscope imaging, the needle tip position can be tracked, providing needle tip position tracking information.

Description

Technical Field

[0001] The present invention relates to the field of optical imaging technology, and in particular to an OCT system in which Ascan depth perception and three-dimensional imaging are simultaneously performed. Background Art

[0002] Subretinal injection surgery is one of the effective delivery methods for therapeutic drugs related to fundus diseases. For subretinal injection of drugs, it is a treatment method that directly injects drugs into a tiny subretinal space between the retina and the choroid. Subretinal injection can be used to treat a variety of eye diseases, such as macular degeneration, which can lead to symptoms such as decreased vision and distorted vision, and can be treated by injecting anti-VEGF, steroids and Faricimab new bispecific antibodies; diabetic retinopathy, which can lead to symptoms such as rupture and hemorrhage of retinal blood vessels, and can be treated by intraocular injection of anti-VEGF drugs; retinal vein occlusion, which can lead to retinal ischemia, hypoxia, sharp decrease in vision, blurred vision and other symptoms, and requires subretinal injection of steroid drugs or anti-VEGF drugs; retinal inflammation, which can cause decreased vision, blurred vision, pain and other symptoms, requires injection of antibiotics into the eye to control the infection;

[0003] Subretinal drug injections offer advantages over traditional treatments, such as oral or intravenous medications. They are characterized by high efficacy, direct action at the lesion, rapid onset of action, minimal side effects, reduced systemic drug exposure, and the ability to adjust the dosage and frequency of injections based on the patient's condition and response.

[0004] Currently, subretinal drug injection therapy is generally performed by professional ophthalmologists, requiring high technical skills and experience. Ocular surgery has its own particularities. Due to its small size and delicate structure, the extremely delicate and complex internal structure, and the narrow surgical space, the doctor's operating precision is extremely high. In addition, ocular tissues such as the cornea and retina are very fragile and easily damaged. The slightest mistake can cause irreversible vision loss. Precise control of the needle tip depth is also crucial for subretinal injection, because shallow injection will not release enough drug, while too deep injection may cause irreparable damage to the retinal pigment epithelium and lead to blood vessel rupture. On the other hand, this critical depth control will be affected by the surgeon's hand tremor and visual artifacts caused by the microscopic view of the target area.

[0005] During fundus injection surgery, surgical instrument navigation is primarily monitored through microscopy, 3D fundus OCT (optical coherence tomography), or a combination of both. However, these methods have limitations. Microscopy only provides a two-dimensional projection image, making it difficult to observe the injection depth of the surgical instrument after it enters the subretina. This requires visual estimation and judgment, which greatly challenges the surgeon's experience. 3D fundus OCT imaging, on the other hand, uses light sources that cannot penetrate the surgical instrument. The resulting image is a 3D image obscured by the instrument. When the instrument is injected into the tissue, the obscured area becomes a blank area.

[0006] Since the above-mentioned imaging methods lack quantitative subretinal visual depth feedback, it is difficult to perceive the insertion depth of surgical instruments during surgery. The depth can only be judged by the naked eye and experience, which brings uncertainty to the surgical process, affects the surgical effect, and hinders the widespread application of this treatment.

[0007] The existing solutions are as follows:

[0008] Solution 1: Microscope + Robot Method -> Estimates the needle tip position by controlling robot motion and the microscope's overhead projection image. This method only provides a projected plan view, but no depth information. This method is susceptible to changes in tissue elasticity and the hardness and flexibility of surgical instruments, making it insufficient for accurately estimating the needle tip's depth within the fundus tissue.

[0009] Option 2: 3D ultrasound + robotic approach -> Lacks sufficient accuracy for subretinal interventional therapy. This imaging method typically provides a needle tip positioning error of approximately 500μm, while the average retinal thickness is approximately 250μm, so the maximum error in needle positioning is relatively large.

[0010] Option 3: Microscopy + OCT B-mode + Robotic Approach -> The relative position of the injection needle to the B-scan acquisition direction, taking into account the tool's contour, insertion direction, and size, allows for the identification of the relevant region of interest around the needle tip from the binary segmentation map. The surface depth of each retinal layer is obtained from the B-mode segmentation map. However, because the OCT imaging light source cannot penetrate the surgical instrument tip, accurate quantitative perception of the depth of the needle tip into the tissue is difficult.

[0011] Citing the paper DOI: 10.1142 / S1793545821400095, this solution integrates B-mode OCT imaging with microscope imaging. The OCT module uses a swept-frequency light source emitting a 1060nm central wavelength with a maximum bandwidth of 100nm, which is split into two paths by a coupler with an 80:20 splitting ratio. One path, serving as the sample arm, passes through a collimator and scanning galvanometer mirror into the microscope, and then through the microscope's reflector and objective lens into the eye. The other reference arm passes through a polarization controller (PC), collimator, focusing lens, and collimator into a fiber coupler with a 50:50 splitting ratio. The collected signal is output by a balanced detector and displayed on a computer screen.

[0012] Currently, ophthalmic microinjection surgery uses a single microscope + OCT navigation. The microscope only provides a single plane projection visual feedback. The microscope has limited observation targets and lacks additional depth auxiliary information. It is only suitable for needle tips that are translucent or transparent. It is unable to perceive the process of the needle tip inserting into the retinal layer, and it is difficult to perceive the needle tip injection depth through traditional microscope views.

[0013] Moreover, since surgeons completely rely on manual operation tools, stereomicroscope imaging and OCT B-mode imaging feedback, physiological tremors and human visual resolution ability at the axial (depth direction) micrometer scale are limited. The needle tip tool may block the injection site, and OCT imaging cannot penetrate, and the image of the position blocked by the surgical instrument will be missing.

[0014] Therefore, in fundus surgery, the current solutions, on the one hand, cannot achieve imaging of the fundus retina, and on the other hand, cannot obtain depth-direction position perception information of the surgical instrument (needle) to achieve tracking of the needle tip position, and therefore cannot meet actual needs. Summary of the Invention

[0015] In view of this, the present invention provides an OCT system that can simultaneously perform Ascan depth perception and three-dimensional imaging, which can not only realize scanning optical coherence tomography of the fundus retina, but also obtain depth-direction position perception information of the surgical instrument (needle). Combined with the projection plane provided by microscope imaging, the needle tip position can be tracked, and needle tip position tracking can be provided through this information.

[0016] To achieve the above objectives, the technical solution of the present invention is: an Ascan OCT system that simultaneously operates in depth perception and three-dimensional imaging, including: a swept light source, a fiber optic coupler, a fiber optic probe sensing module, a three-dimensional scanning OCT imaging module, a system control and image acquisition module, and an image display module.

[0017] The imaging process of the OCT system target is that the near-infrared light source is first emitted by the swept light source, and after passing through the fiber coupler, it is divided into two optical coherence tomography imaging paths, one of which serves as the input of the fiber probe sensing module, and the other serves as the input of the three-dimensional scanning OCT imaging module.

[0018] In the fiber optic probe sensing module, the near-infrared light passes through the fiber optic coupler 2 and is divided into two paths, one of which is the reference arm A and the other is the sample arm A; the reference arm A is split by the fiber optic coupler 3, and one of the paths is connected to a section of single-mode optical fiber 1 after splitting. The single-mode optical fiber 1 is for dispersion matching, and then the light beam is collimated by the fiber optic collimator 1 and reflected by the reflector connected to the linear displacement platform. Then the light beam returns and passes through the fiber optic collimator 1, single-mode optical fiber 1, fiber optic coupler 3, and then passes through another fiber optic coupler 4 and enters the balanced detector; the sample arm Path A uses fiber coupler five, which is connected to single-mode fiber two and a fiber probe after splitting. After being emitted, the light beam is focused by the fiber probe at the front end to the sample tissue for imaging. After being scattered by the sample, it returns to fiber coupler five along the original path of sample arm A, and then enters the balanced detector through fiber coupler four. Before entering the balanced detector, the light beams returned by sample arm A and reference arm A first pass through fiber coupler four to generate an interference signal. After the generated interference signal passes through the balanced detector, the optical signal is converted into an electrical signal, and then enters the system control and image processing module through the signal acquisition card.

[0019] For the three-dimensional scanning OCT imaging module, after passing through the fiber coupler six, it is divided into two paths again, one of which is the reference arm B and the other is the sample arm B; the reference arm B path uses the fiber coupler seven, and after splitting, one of the paths is connected to the fiber collimator two, and after collimating the light beam, it is focused by the optical lens, and then reflected at the reflector, and the light beam returns along the original path of the reference arm B; the sample arm B path uses the fiber coupler eight, and after splitting, it is connected to the fiber collimator three, and after collimating the light beam, it enters the galvanometer module, and the galvanometer module scans the light beam two-dimensionally along the sample plane, and then enters the microscope objective for focusing. After exiting, the light beam is focused into the sample tissue through the objective lens for imaging, and after being scattered by the sample, it returns to the fiber coupler eight along the original path of the sample arm B; then the light beams after the sample arm B and the reference arm B return to the fiber coupler eight before entering the balanced detector, and then generate interference signals. After the generated interference signal passes through the balanced detector, the optical signal is converted into an electrical signal, and then enters the system control and image processing module through the signal acquisition card for processing.

[0020] The microscope provides planar projection information for tracking the needle tip or surgical instrument.

[0021] Preferably, the light splitting ratios of the first, third, fourth, seventh and ninth optical fiber couplers are all 50:50.

[0022] Preferably, the splitting ratio of the second optical fiber coupler is 90:10, wherein the one with 10% splitting is the reference arm A, and the one with 90% splitting is the sample arm A.

[0023] Preferably, the splitting ratio of the optical fiber coupler five is 90:10, wherein after the sample arm A is split by the optical fiber coupler five, the path with a splitting ratio of 10% is connected to the single-mode optical fiber two and the optical fiber probe, and the path with a splitting ratio of 90% is left vacant; after scattering by the sample, the light returns to the optical fiber coupler five along the original path of the sample arm A, and after being split by the optical fiber coupler five, the path with a splitting ratio of 90% is connected to the optical fiber coupler four.

[0024] Preferably, the optical fiber coupler 6 has a light splitting ratio of 90:10, wherein the one with a light splitting ratio of 10% is the reference arm B, and the one with a light splitting ratio of 90% is the sample arm B.

[0025] Preferably, the splitting ratio of the optical fiber coupler eight is 75:25, wherein one path of the sample arm B uses the optical fiber coupler eight, and the path with a splitting ratio of 25% after splitting is connected to the optical fiber collimator three; after being emitted, the light beam is focused by the objective lens into the sample tissue for imaging, and after being scattered by the sample, it returns to the optical fiber coupler eight along the original path of the sample arm B. After being split by the optical fiber coupler eight, the path with a splitting ratio of 75% is connected to the optical fiber coupler nine.

[0026] Preferably, the single-mode optical fiber 1 and the single-mode optical fiber 2 are made of the same material.

[0027] Furthermore, the galvanometer module has two-directional scanning galvanometers, which are respectively controlled to rotate by two motors, and the scanning directions of the two motors are perpendicular. The two motors are controlled by the control voltage signal output by the I / O card to perform two-dimensional scanning of the light beam along the sample plane.

[0028] Furthermore, the optical fiber probe is fixed to the needle part of the syringe through a fixing frame. The optical fiber probe includes a single-mode optical fiber with a total diameter not exceeding 150 μm, a coreless optical fiber for light beam diffusion, and a spherical lens for focusing the light beam; a protective sleeve with a certain air gap is installed at the front end of the spherical lens, and the focusing ability is achieved by designing the air gap length of the protective sleeve.

[0029] Preferably, the fiber optic probe has a size smaller than 200 μm.

[0030] Beneficial effects:

[0031] 1: This invention proposes an OCT system that simultaneously performs Ascan depth perception and three-dimensional imaging. This system utilizes a single light source within a single acquisition card to simultaneously perform A-scan and 3D OCT imaging. This system can simultaneously perform A-scan-based depth perception of surgical instruments relative to tissues, as well as three-dimensional high-resolution structural imaging. The depth perception function is integrated with the surgical instrument via a single-mode fiber probe. The three-dimensional high-resolution structural imaging can be integrated with a microscope or used independently for tissue structural imaging. The system simultaneously performs quantitative fundus imaging analysis and three-dimensional depth perception of the subretinal surgical instrument position. Therefore, it can perform both optical coherence tomography (OCT) imaging of the fundus and the retina, while also obtaining depth-direction positional information of the surgical instrument (needle). Combined with the projection plane provided by the microscope imaging, the needle tip position can be tracked, and this information provides needle tip position tracking.

[0032] 2: The present invention proposes an Ascan OCT system that simultaneously performs depth perception and three-dimensional imaging, and provides a fiber optic probe solution that can perform high-efficiency depth perception in the fundus fluid environment. This solves the problem that the fiber optic probe can only focus well in air but not in liquid under the conditions of limited size and relatively small refractive index difference. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A schematic diagram of the structure of an Ascan OCT system that simultaneously performs depth perception and three-dimensional imaging;

[0034] Figure 2 A diagram showing the structural relationship between the optical fiber probe and the syringe needle;

[0035] Figure 3 Detailed schematic diagram of the spherical lens and single-mode optical fiber in the present invention. DETAILED DESCRIPTION

[0036] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0037] The present invention provides an OCT system that can simultaneously perform Ascan depth perception and three-dimensional imaging. Figure 1 As shown, it includes: a swept light source, a fiber coupler, a fiber probe sensing module, a three-dimensional scanning OCT imaging module, a system control and image acquisition module, and an image display module.

[0038] The imaging process of the OCT system target is that the near-infrared light source is first emitted by the swept light source, and after passing through the fiber coupler, it is divided into two optical coherence tomography imaging paths, one of which serves as the input of the fiber probe sensing module, and the other serves as the input of the three-dimensional scanning OCT imaging module.

[0039] In the fiber optic probe sensing module, the near-infrared light passes through the fiber optic coupler 2 and is divided into two paths, one of which is the reference arm A and the other is the sample arm A; the reference arm A is split by the fiber optic coupler 3, and one of the paths is connected to a section of single-mode optical fiber 1 after splitting. The single-mode optical fiber 1 is for dispersion matching, and then the light beam is collimated by the fiber optic collimator 1 and reflected by the reflector connected to the linear displacement platform. Then the light beam returns and passes through the fiber optic collimator 1, single-mode optical fiber 1, fiber optic coupler 3, and then passes through another fiber optic coupler 4 and enters the balanced detector; the sample arm Path A uses fiber coupler five, which is connected to single-mode fiber two and a fiber probe after splitting. After being emitted, the light beam is focused by the fiber probe at the front end to the sample tissue for imaging. After being scattered by the sample, it returns to fiber coupler five along the original path of sample arm A, and then enters the balanced detector through fiber coupler four. Before entering the balanced detector, the light beams returned by sample arm A and reference arm A first pass through fiber coupler four to generate an interference signal. After the generated interference signal passes through the balanced detector, the optical signal is converted into an electrical signal, and then enters the system control and image processing module through the signal acquisition card.

[0040] For the three-dimensional scanning OCT imaging module, after passing through the fiber coupler six, it is divided into two paths again, one of which is the reference arm B and the other is the sample arm B; the reference arm B path uses the fiber coupler seven, and after splitting, one of the paths is connected to the fiber collimator two, and after collimating the light beam, it is focused by the optical lens, and then reflected at the reflector, and the light beam returns along the original path of the reference arm B; the sample arm B path uses the fiber coupler eight, and after splitting, it is connected to the fiber collimator three, and after collimating the light beam, it enters the galvanometer module, and the galvanometer module scans the light beam two-dimensionally along the sample plane, and then enters the microscope objective for focusing. After exiting, the light beam is focused into the sample tissue through the objective lens for imaging, and after being scattered by the sample, it returns to the fiber coupler eight along the original path of the sample arm B; then the light beams after the sample arm B and the reference arm B return to the fiber coupler eight before entering the balanced detector, and then generate interference signals. After the generated interference signal passes through the balanced detector, the optical signal is converted into an electrical signal, and then enters the system control and image processing module through the signal acquisition card for processing.

[0041] The microscope provides planar projection information for tracking the needle tip or surgical instrument.

[0042] The fiber coupler used in the present invention has a structure in which both ends can serve as input and output ends, and each end has two connectors. When one connector at the input end receives input, the fiber coupler splits the light internally, and then outputs the two split paths through the two connectors at the output end.

[0043] In the embodiment of the present invention, the light splitting ratios of the first, third, fourth, seventh and ninth optical fiber couplers are all 50:50.

[0044] In the embodiment of the present invention, the optical fiber coupler 2 has a light splitting ratio of 90:10, wherein one path with a light splitting ratio of 10% is the reference arm A, and one path with a light splitting ratio of 90% is the sample arm A.

[0045] In the embodiment of the present invention, the optical fiber coupler five has a light splitting ratio of 90:10, wherein, after the sample arm A is split by the optical fiber coupler five, the path with a splitting ratio of 10% is connected to the single-mode optical fiber two and the optical fiber probe, and the path with a splitting ratio of 90% is left vacant; after scattering by the sample, the light returns to the optical fiber coupler five along the original path of the sample arm A, and after being split by the optical fiber coupler five, the path with a splitting ratio of 90% is connected to the optical fiber coupler four.

[0046] In the embodiment of the present invention, the optical fiber coupler 6 has a light splitting ratio of 90:10, wherein the one with a light splitting ratio of 10% is the reference arm B, and the one with a light splitting ratio of 90% is the sample arm B.

[0047] In an embodiment of the present invention, the optical fiber coupler eight has a light splitting ratio of 75:25, wherein one path of the sample arm B uses the optical fiber coupler eight, and the path with a light splitting ratio of 25% after splitting is connected to the optical fiber collimator three; the emitted light beam is focused by the objective lens into the sample tissue for imaging, and after being scattered by the sample, it returns to the optical fiber coupler eight along the original path of the sample arm B. After being split by the optical fiber coupler eight, the path with a light splitting ratio of 75% is connected to the optical fiber coupler nine.

[0048] In the embodiment of the present invention, the single-mode optical fiber 1 and the single-mode optical fiber 2 are made of the same material.

[0049] The galvanometer module has two scanning galvanometers, which are controlled by two motors to rotate in perpendicular directions. The two motors are controlled by the control voltage signal output by the I / O card to perform two-dimensional scanning of the light beam along the sample plane.

[0050] In the embodiment of the present invention, the optical fiber probe is fixed to the needle part of the syringe through a fixing frame, and its structure is as follows: Figure 2 As shown in FIG, the optical fiber probe includes a single-mode optical fiber with a total diameter not exceeding 150 μm, a coreless optical fiber for beam diffusion, and a spherical lens for focusing the beam; a protective sleeve with a certain air gap is installed at the front end of the spherical lens, and the focusing capability is achieved by designing the air gap length of the protective sleeve.

[0051] The fiber optic probe is relatively complex, including a single-mode optical fiber with a specific total diameter not exceeding 150 μm, a coreless optical fiber for beam diffusion, and a spherical lens for focusing the beam, such as Figure 3As shown. A retaining clip is used to secure the probe and needle. After installation, it is secured with UV glue to prevent it from falling off. A protective sleeve with a certain air gap is installed at the front end of the spherical lens. The air gap length can be designed to achieve a certain degree of focusing capability. The protective sleeve is added because the overall size of the fiber optic probe must be less than 200μm. The probe's focusing capability is determined by the probe's spherical diameter R and the coreless fiber length L. During the optical design process, the amount of change that can be made is relatively small. With a diameter of 200μm and within the ocular fluid, focusing capability is insufficient within a specific distance range (e.g., 2-3mm). Because the refractive index of the spherical lens is very close to that of the ocular fluid, the refractive index difference is relatively small, resulting in weak light deflection. This makes it difficult to focus in liquid as easily as in air. Therefore, the protective sleeve can be added to artificially increase the refractive index difference, allowing light to focus within a certain air gap before entering the ocular fluid.

[0052] Focusing fiber optic probes (which concentrate energy and facilitate imaging) deflect the light beam when encountering a refractive index gradient. While focused in air, they lose focus in liquid. This is because the refractive index of commercially available optical fibers (1.46) is very close to that of the intraocular fluid (1.33). This is limited by the size and fiber materials used (limitations include the fixed refractive index of commercially available optical fibers, which cannot be customized with a specific refractive index; the overall fiber optic probe size must be less than 200 μm, otherwise it cannot be integrated with the needle; and the gradient refractive index (GRIN) lens is expensive and large). By adding a vacuum chamber (refractive index 1.0) with a certain length to the probe's spherical tip to isolate the probe from the surrounding liquid, a larger refractive index difference (air gap) can be created between the spherical tip and the surrounding liquid, resulting in a greater degree of light beam deflection and achieving optimal focusing.

[0053] In summary, the above are only preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An OCT system with simultaneous depth perception and three-dimensional imaging, characterized by: include: Sweep frequency light source, fiber coupler 1, fiber probe sensing module, 3D scanning OCT imaging module, system control and image acquisition module, image display module; The imaging process of the OCT system target is as follows: first, a near-infrared light source is emitted by a swept light source, which passes through a fiber coupler and is then divided into two optical coherence tomography imaging paths, one of which serves as the input of the fiber probe sensing module, and the other serves as the input of the three-dimensional scanning OCT imaging module; In the fiber optic probe sensing module, the near-infrared light passes through the fiber optic coupler 2 and is divided into two paths, one of which is the reference arm A and the other is the sample arm A; the reference arm A passes through the fiber optic coupler 3 for splitting, and after splitting, one of the paths is connected to a section of single-mode optical fiber 1, which is for dispersion matching. The light beam is then collimated by the fiber optic collimator 1 and reflected by the reflector connected to the linear displacement platform. The light beam then returns and passes through the fiber optic collimator 1, the single-mode optical fiber 1, the fiber optic coupler 3, and then passes through another fiber optic coupler 4 and enters the balanced detector. ; The sample arm A adopts the fiber coupler five, which is connected to the single-mode fiber two and the fiber probe after splitting. After the light is emitted, it is focused by the fiber probe at the front end to the sample tissue for imaging. After being scattered by the sample, it returns to the fiber coupler five along the original path of the sample arm A, and then enters the balanced detector through the fiber coupler four; before entering the balanced detector, the light beams returned by the sample arm A and the reference arm A first pass through the fiber coupler four to generate an interference signal. After the generated interference signal passes through the balanced detector, the optical signal is converted into an electrical signal, and then enters the system control and image processing module through the signal acquisition card; For the three-dimensional scanning OCT imaging module, after passing through the fiber coupler six, it is divided into two paths again, one of which is the reference arm B and the other is the sample arm B; the reference arm B path uses the fiber coupler seven, and after splitting, one of the paths is connected to the fiber collimator two, and after the collimated light beam is focused by the optical lens, and then reflected at the reflector, the light beam returns along the original path of the reference arm B; the sample arm B path uses the fiber coupler eight, and after splitting, it is connected to the fiber collimator three, and after the collimated light beam enters the galvanometer module, which scans the light beam two-dimensionally along the sample plane, and then enters the microscope objective for focusing. After being emitted, the light beam is focused into the sample tissue through the objective lens for imaging, and after being scattered by the sample, it returns to the fiber coupler eight along the original path of the sample arm B; then the light beams after the sample arm B and the reference arm B return to the fiber coupler eight before entering the balanced detector, and then generate interference signals. After the generated interference signals pass through the balanced detector, the optical signals are converted into electrical signals, and then enter the system control and image processing module through the signal acquisition card for processing; The microscope provides planar projection information for tracking the needle tip or surgical instrument.

2. The OCT system capable of simultaneously performing Ascan depth perception and three-dimensional imaging according to claim 1, characterized in that: The optical fiber couplers one, three, four, seven and nine have a light splitting ratio of 50:

50.

3. The OCT system capable of simultaneously performing Ascan depth perception and three-dimensional imaging according to claim 1, wherein: The optical fiber coupler 2 has a light splitting ratio of 90:10, wherein the one with a light splitting ratio of 10% is the reference arm A, and the one with a light splitting ratio of 90% is the sample arm A.

4. The OCT system capable of simultaneously performing Ascan depth perception and three-dimensional imaging according to claim 1 or 2, characterized in that: The optical fiber coupler five has a light splitting ratio of 90:

10. After the sample arm A is split by the optical fiber coupler five, the path with a splitting ratio of 10% is connected to the single-mode optical fiber two and the optical fiber probe, and the path with a splitting ratio of 90% is left vacant. After scattering by the sample, the light returns to the optical fiber coupler five along the original path of the sample arm A. After being split by the optical fiber coupler five, the path with a splitting ratio of 90% is connected to the optical fiber coupler four.

5. The Ascan depth perception and three-dimensional imaging OCT system according to claim 1 or 2, characterized in that: The optical fiber coupler 6 has a light splitting ratio of 90:10, wherein the one with a light splitting ratio of 10% is the reference arm B, and the one with a light splitting ratio of 90% is the sample arm B.

6. The Ascan depth perception and three-dimensional imaging OCT system according to claim 1 or 2, characterized in that: The optical fiber coupler eight has a splitting ratio of 75:25, wherein one path of the sample arm B uses the optical fiber coupler eight, and the path with a splitting ratio of 25% after splitting is connected to the optical fiber collimator three; the emitted light beam is focused by the objective lens into the sample tissue for imaging, and after being scattered by the sample, it returns to the optical fiber coupler eight along the original path of the sample arm B. After being split by the optical fiber coupler eight, the path with a splitting ratio of 75% is connected to the optical fiber coupler nine.

7. The OCT system capable of simultaneously performing Ascan depth perception and three-dimensional imaging according to claim 1, characterized in that: The single-mode optical fiber 1 and the single-mode optical fiber 2 are made of the same material.

8. The OCT system capable of simultaneously performing Ascan depth perception and three-dimensional imaging according to claim 1, wherein: The galvanometer module has two scanning galvanometers, which are respectively controlled to rotate by two motors, and the two scanning directions are perpendicular. The two motors are controlled by the control voltage signal output by the I / O card to perform two-dimensional scanning of the light beam along the sample plane.

9. The OCT system capable of simultaneously performing Ascan depth perception and three-dimensional imaging according to claim 1, wherein: The fiber optic probe is fixed to the needle part of the syringe through a fixing frame. The fiber optic probe includes a single-mode optical fiber with a total diameter not exceeding 150 μm, a coreless optical fiber for light beam diffusion, and a spherical lens for focusing the light beam. A protective sleeve with a certain air gap is installed at the front end of the spherical lens, and the focusing ability is achieved by designing the air gap length of the protective sleeve.

10. The OCT system capable of simultaneously performing Ascan depth perception and three-dimensional imaging according to claim 1, wherein: The size of the optical fiber probe is less than 200 μm.

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