An integrated optical fiber endoscope for vascular wall imaging applications and a method of manufacturing

Abstract

The application provides an integrated optical fiber endoscope for blood vessel wall imaging application and a preparation method, relates to the field of medical optical fiber device preparation, and the endoscope directly manufactures a micro probe integrated with a reflecting surface and a customized objective lens at a single-mode optical fiber end face. The overall size of the probe is only tens of microns, and the probe has the characteristics of compact structure, stable optical path and high imaging resolution. In the preparation process, the integrated forming of the optical structure can be realized, and the key parameters such as the lens curvature and the reflection angle can be flexibly controlled according to actual imaging requirements. The endoscope can realize high-quality imaging under a millimeter-level working distance, and is suitable for the observation and accurate diagnosis of narrow cavities in a living body.

Description

Technical Field

[0001] This invention relates to the field of medical fiber optic device fabrication, and in particular to an integrated fiber optic endoscope for blood vessel wall imaging applications and its fabrication method. Background Technology

[0002] Endoscopes are widely used in the medical field, especially in minimally invasive surgery, due to their ease of operation, controllable cost, and versatility. Their non-invasive nature allows for high-precision observation of internal human structures, making them a key component of modern minimally invasive diagnostic and treatment systems. However, traditional endoscopes often rely on independently fabricated microlenses or prisms, assembled to the ends of optical fibers through bonding or mechanical fixation. This process suffers from limitations such as the inability to manufacture in a single unit, low bonding strength, and difficulty in further miniaturization, restricting their application in higher precision and more complex environments.

[0003] Therefore, there is a need to provide an integrated fiber optic endoscope for vascular wall imaging applications and its fabrication method to solve the above problems. Summary of the Invention

[0004] The purpose of this invention is to provide an integrated fiber optic endoscope and its fabrication method for vascular wall imaging applications. It is manufactured directly on the end face of a single-mode fiber, and the endoscope probe integrates a reflective surface and an imaging lens. High-quality optical detection and imaging are achieved by controlling the optical path. It has advantages such as miniaturized structure, clear imaging, and wide applicability.

[0005] To achieve the above objectives, this invention provides an integrated fiber optic endoscope for vascular wall imaging applications, comprising an endoscope body. The endoscope body is positioned at the end face of a single-mode fiber. The endoscope body structure is configured as an endoscope probe with a height of 50μm-60μm from the end face of the single-mode fiber and a length and width of 60μm. The endoscope probe includes an objective lens and a reflecting surface. The angle between the reflecting surface and the end face of the single-mode fiber is set to 60 degrees, and the objective lens has a curvature of 1.91mm. -1 A plano-convex lens with a focal length of 1mm.

[0006] Preferably, it also includes an external sheath and a drive mechanism connected to the fiber optic sensing probe.

[0007] Preferably, the endoscopic probe is obtained by two-photon polymerization 3D printing.

[0008] Preferably, the endoscopic probe and the single-mode fiber are integrated into one structure, with the core diameter of the single-mode fiber set to 8-10 μm and the cladding diameter set to 125 μm.

[0009] A method for fabricating an integrated fiber optic endoscope for blood vessel wall imaging applications includes the following steps: S1: Remove the coating of the single-mode fiber and clean the end face of the single-mode fiber. Fix the end of the single-mode fiber away from the end face to the fiber clamp. S2: Photoresist is dropped onto the processing objective lens of the 3D printing equipment. The image on the surface of the processing objective lens is deflected by a refracting prism and then transmitted to the aperture. After being filtered by the aperture, it is focused onto the CCD image sensor. S3: The computer is connected to both the CCD image sensor and the laser. S4: Guided by real-time images from the computer, the moving fiber optic clamp gradually brings the processing objective of the 3D printing equipment closer to and focuses on the end face of the single-mode fiber. S5: Immerse the end face of the single-mode fiber in the photoresist to complete the focusing preparation; S6: Start the photopolymerization process. The laser beam emitted from the laser is adjusted in diameter by the beam expander, then deflected by the plane mirror to the refracting prism, and finally focused by the processing lens of the 3D printing equipment onto the end face of the single-mode fiber held by the fiber optic clamp. S7: The computer recognizes and processes the preset 3D model, controls the laser beam to scan, cures the photoresist layer by layer, and controls the exposure of the laser beam according to the model to complete the preparation of the endoscope. S8: After preparation, immerse the single-mode optical fiber in propylene glycol methyl ether acetate solution for 10-15 minutes to dissolve the uncured photoresist, and then leave it to stand in the air to complete the processing.

[0010] Preferably, the Young's modulus of the photoresist in S5 is set to 1.5 GPa, and the density is set to 1.26 g / cm³. 3 The Poisson's ratio was set to 0.3, and the refractive index was set to 1.52.

[0011] Preferably, in S7, the structure of the endoscopic probe is modeled in three dimensions in a computer. The model is saved in .stl format and imported into Describe software for preprocessing. The preprocessed file guides the laser to expose a specific area on the fiber end face. Describe software slices the three-dimensional model into layers with a thickness of 300nm and automatically plans the laser scanning path.

[0012] Therefore, the present invention employs the above-mentioned integrated fiber optic endoscope and its fabrication method for vascular wall imaging applications, and the technical effects are as follows: (1) The present invention uses two-photon polymerization 3D printing technology to manufacture a micro endoscope on the end face of a single-mode fiber. The manufacturing precision can reach the micrometer level. The structure is integrally formed and has good consistency, which significantly improves the stability and imaging quality of the optical system.

[0013] (2) The miniature endoscope designed in this invention integrates a reflective surface and an objective lens, with a compact and reasonable optical path, enabling millimeter-level working distance and high spatial resolution imaging, and is suitable for fine observation inside narrow cavities.

[0014] (3) The all-fiber design of the endoscope in this invention gives it good mechanical flexibility and anti-electromagnetic interference capability, providing a basis for detection in complex environments. Attached Figure Description

[0015] Figure 1 This is a flowchart illustrating the fabrication method of an integrated fiber optic endoscope for blood vessel wall imaging applications according to the present invention. Figure 2 This is a schematic diagram of the fiber optic endoscope structure and usage method proposed in the embodiments of the present invention; Figure 3 This is a three-dimensional model of the fiber optic endoscope structure proposed in this embodiment of the invention and its focusing schematic diagram; Figure 4 These are structural diagrams of the fiber optic endoscope structure proposed in the embodiments of the present invention from different viewpoints under a microscope.

[0016] Attached Figure Captions 1. Single-mode optical fiber; 2. Processing objective lens for 3D printing equipment; 3. Fiber optic clamp; 4. Computer; 5. CCD image sensor; 6. Aperture; 7. Laser; 8. Beam expander; 9. Plane mirror; 10. Refraction prism. Detailed Implementation

[0017] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0018] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0019] Example 1 like Figure 3 and Figure 4 As shown, this invention provides an integrated fiber optic endoscope for vascular wall imaging applications, comprising an endoscope body. The endoscope body is positioned at the end face of a single-mode fiber. The endoscope body structure is configured as an endoscope probe with a height of 50μm-60μm from the end face of the single-mode fiber and a length and width of 60μm. The endoscope probe includes an objective lens and a reflecting surface. The angle between the reflecting surface and the end face of the single-mode fiber is set to 60 degrees, and the objective lens has a curvature of 1.91mm. -1The endoscope uses a plano-convex lens with a focal length of 1mm. The endoscope probe and single-mode fiber are integrated into a single structure. The endoscope probe is obtained through two-photon polymerization 3D printing. The core diameter of the single-mode fiber is set to 8-10μm, and the cladding diameter is set to 125μm. Printing the endoscope probe onto the end face of the single-mode fiber does not significantly increase the overall size of the probe, and the integrated endoscope probe can still travel smoothly through narrow channels within the human body and complete imaging.

[0020] It also includes an external sheath and a drive mechanism connected to the fiber optic sensing probe for guiding and maneuvering the fiber optic sensing probe into the target area.

[0021] like Figure 1 and Figure 2 As shown, a method for fabricating an integrated fiber optic endoscope for blood vessel wall imaging applications includes the following steps: S1: Remove the coating layer of single-mode fiber 1 and clean the end face of single-mode fiber 1, and fix the end of single-mode fiber 1 away from the end face onto fiber clamp 3. S2: Photoresist is dropped onto the processing objective lens 2 of the 3D printing equipment. The image on the surface of the processing objective lens 2 of the 3D printing equipment is deflected by the refracting prism 10 and then transmitted to the aperture 6. After being filtered by the aperture 6, it is focused onto the CCD image sensor 5. S3: Computer 4 is connected to CCD image sensor 5 and laser 7 respectively; S4: Under the real-time image guidance of computer 4, the moving fiber optic clamp 3 gradually brings the processing objective lens 2 of the 3D printing equipment closer to and focuses on the end face of the single-mode fiber 1; during the movement, the x-axis and y-axis directions are first adjusted to ensure that the single-mode fiber 1 is aligned with the processing objective lens 2 of the 3D printing equipment, and then the fiber optic clamp 3 is slowly pushed forward along the direction perpendicular to the processing objective lens of the 3D printing equipment. S5: Immerse the end face of single-mode fiber 1 in the photoresist to prepare for focusing; observe the sharpness of the edge of the end face of single-mode fiber 1 on the monitor of computer 4 to determine the focusing status. To confirm whether the fiber end face has moved to the focal plane of the processing objective lens of the 3D printing equipment, a brief laser exposure can be triggered, and the focusing status can be verified by observing the change in laser spot intensity. In S5, the Young's modulus of the photoresist is set to 1.5 GPa, and the density is set to 1.26 g / cm³. 3 The Poisson's ratio was set to 0.3, and the refractive index was set to 1.52.

[0022] S6: Start the photopolymerization process. The laser beam emitted from the laser 7 is adjusted in diameter by the beam expander 8, then deflected by the plane mirror 9 to the refracting prism 10, and finally focused by the processing objective lens 2 of the 3D printing equipment onto the end face of the single-mode fiber 1 held by the fiber optic clamp 3. S7: Computer 4 identifies and processes the preset 3D model, controls the laser beam to scan, cures the photoresist layer by layer, and controls the exposure of the laser beam according to the model to complete the fabrication of the endoscope; In S7, the structure of the endoscope probe is 3D modeled in computer 4, the model is saved in .stl format and imported into Describe software for processing preprocessing, the preprocessed file guides laser 7 to expose in a specific area of ​​the fiber end face, Describe software slices the 3D model layer by layer, the thickness of the slice is set to 300nm, and automatically plans the laser scanning path.

[0023] S8: After preparation, immerse the single-mode fiber 1 in propylene glycol methyl ether acetate solution for 10-15 minutes to dissolve the uncured photoresist, and then leave it to stand in the air to complete the processing.

[0024] The working principle of the integrated fiber optic endoscope is as follows: A single-mode fiber optic cable with the endoscope body is fixed to the fiber optic clamp as a probe, aligning the probe with the sample and ensuring a secure connection between the fiber optic cable and the clamp. The working optical path is then established: the endoscope body is connected to an optical coupler via fiber optic cable, and a low-coherence light source and a detector are connected to the input and output ports of the coupler, respectively. The other end of the detector is connected to the signal processing unit and the host computer. The tunable reference arm at the other output of the coupler is adjusted so that the optical path of the tunable reference arm matches the optical path of the sample arm containing the endoscope body within the coherence length of the light source. In operation, the low-coherence light emitted by the light source is split by a 90:10 coupler and enters the sample arm and reference arm respectively. The light from the sample arm is transmitted through the endoscope body and illuminates the sample under test. The light reflected back from different depths inside the sample returns along the original path. The light from the reference arm is transmitted through a circulator to a reflector, and the reflected light from the reflector returns along the original path. The two beams are combined in a 50:50 coupler and interfere. The interference signal is differentially detected by a balanced detector and then converted into a digital signal by a data acquisition card. Finally, the host computer processes and reconstructs the digital signal to obtain a layered structural image of the sample in the depth direction.

[0025] Therefore, the present invention adopts the above-mentioned integrated fiber optic endoscope and its preparation method for blood vessel wall imaging applications, which solves the problems of fiber optic endoscopes being unable to be manufactured in an integrated manner and having low structural integration. The designed miniature endoscope lens structure is suitable for high-resolution imaging of narrow cavities.

[0026] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. An integrated fiber optic endoscope for blood vessel wall imaging applications, comprising an endoscope body, characterized in that, The endoscope body is positioned at the end face of a single-mode fiber. The endoscope body structure is configured as an endoscope probe with a height of 50μm-60μm from the end face of the single-mode fiber and a length and width of 60μm. The endoscope probe includes an objective lens and a reflective surface. The angle between the reflective surface and the end face of the single-mode fiber is set to 60 degrees, and the objective lens has a curvature of 1.91mm. -1 A plano-convex lens with a focal length of 1mm.

2. The integrated fiber optic endoscope for vascular wall imaging applications according to claim 1, characterized in that, It also includes an external sheath and a drive mechanism that connect to the fiber optic sensing probe.

3. The integrated fiber optic endoscope for vascular wall imaging applications according to claim 1, characterized in that, The endoscopic probe was obtained through two-photon polymerization 3D printing.

4. An integrated fiber optic endoscope for vascular wall imaging applications according to claim 1, characterized in that, The endoscopic probe and single-mode fiber are integrated into one structure. The core diameter of the single-mode fiber is set to 8-10μm, and the cladding diameter is set to 125μm.

5. A method for fabricating an integrated fiber optic endoscope for vascular wall imaging applications according to any one of claims 1-4, characterized in that: Includes the following steps: S1: Remove the coating of the single-mode fiber and clean the end face of the single-mode fiber. Fix the end of the single-mode fiber away from the end face to the fiber clamp. S2: Photoresist is dropped onto the processing objective lens of the 3D printing equipment. The image on the surface of the processing objective lens is deflected by a refracting prism and then transmitted to the aperture. After being filtered by the aperture, it is focused onto the CCD image sensor. S3: The computer is connected to both the CCD image sensor and the laser. S4: Guided by real-time images from the computer, the moving fiber optic clamp gradually brings the processing objective of the 3D printing equipment closer to and focuses on the end face of the single-mode fiber. S5: Immerse the end face of the single-mode fiber in the photoresist to complete the focusing preparation; S6: Start the photopolymerization process. The laser beam emitted from the laser is adjusted in diameter by the beam expander, then deflected by the plane mirror to the refracting prism, and finally focused by the processing lens of the 3D printing equipment onto the end face of the single-mode fiber held by the fiber optic clamp. S7: The computer recognizes and processes the preset 3D model, controls the laser beam to scan, cures the photoresist layer by layer, and controls the exposure of the laser beam according to the model to complete the preparation of the endoscope. S8: After preparation, immerse the single-mode optical fiber in propylene glycol methyl ether acetate solution for 10-15 minutes to dissolve the uncured photoresist, and then leave it to stand in the air to complete the processing.

6. The method for fabricating an integrated fiber optic endoscope for vascular wall imaging applications as described in claim 5, characterized in that: The Young's modulus of the photoresist in S5 was set to 1.5 GPa, and the density was set to 1.26 g / cm³. 3 The Poisson's ratio was set to 0.3, and the refractive index was set to 1.

52.

7. The method for fabricating an integrated fiber optic endoscope for vascular wall imaging applications as described in claim 5, characterized in that: In S7, the structure of the endoscope probe is modeled in 3D on the computer. The model is saved in .stl format and imported into Describe software for preprocessing. The preprocessed file guides the laser to expose a specific area on the fiber end face. Describe software slices the 3D model into layers with a thickness of 300nm and automatically plans the laser scanning path.

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