A structured light three-dimensional endoscope

Abstract

The present invention proposes a structured light three-dimensional endoscope including an endoscope probe, an endoscope hose, an image processor and a fiber optic light source, wherein: the structural component includes a sealed shell, the endoscope probe includes a miniature camera and a metasurface fiber optic array projection device, the miniature camera is connected to the image processor via the endoscope hose by a data cable, the metasurface fiber optic array projection device is connected to the fiber optic light source via the endoscope hose by an optical fiber bundle, the metasurface fiber optic array projection device includes multiple optical fibers, and the surface of the optical fiber end is engraved with a metasurface holographic layer, and the diffraction pattern of each metasurface holographic layer corresponds to a structured light coding pattern; each optical fiber is lit in turn, and each optical fiber uses the metasurface holographic layer on its end face to project the structured light pattern to the surface of the collected object in turn, and uses the miniature camera to record the deformed structured light pattern formed by the reflection of the collected object surface in turn, and reconstructs the three-dimensional morphology of the collected object surface according to the structured light decoding algorithm.

Description

Technical Field

[0001] The present invention relates to the technical field of medical equipment, and in particular to a structured light three-dimensional endoscope. Background Art

[0002] Structured light 3D endoscopes can achieve 3D measurement in confined spaces and are important instruments in the fields of industrial non-destructive testing, minimally invasive medical surgery, etc. Existing optical 3D endoscopes include binocular stereo vision endoscopes and structured light 3D endoscopes. Structured light 3D reconstruction is an active 3D imaging technology. Structured light can be divided into spatially coded structured light and time-coded structured light. Spatial coding can achieve 3D reconstruction of the object surface by projecting a structured light image, but its reconstruction accuracy is low. Time-coded structured light requires the projection of a series of structured light images, such as phase-shifted sinusoidal stripes, Gray code, etc., and its reconstruction accuracy is higher.

[0003] Application number CN201710294318.9 discloses a structured light 3D endoscopy device comprising an endoscope insertion tube containing a fiber bundle that transmits structured light, a projection lens, and a camera module. Three LED light sources are located outside the endoscope insertion tube and are coupled to the three inlets of the illumination fiber bundle via lenses. The fiber bundle has three inlets and one outlet, and the ends are arranged in a regular rectangular array, with three columns forming a cycle. Within each cycle, different columns correspond to light from different light sources. The camera module includes a camera objective lens, a CMOS sensor for collecting images, and a CMOS driving circuit. The three LED light sources work in a time-sharing manner. The illumination light passes through a regularly arranged optical fiber bundle array to generate structured light stripes with different phases and intervals of light and dark, which are then amplified by the projection lens to illuminate the tissues in the body. The camera module collects the structured light illumination image and transmits it to the camera interface through the driving circuit and further to the camera control unit CCU for decoding and processing to obtain a depth map of the tissues in the body and realize three-dimensional reconstruction. The device uses three LED light sources plus an optical fiber bundle to project phase stripes, but its projection optical path is large and it is difficult to project high-resolution structured light patterns in a small space. Summary of the Invention

[0004] In order to solve the problems of large size and low resolution of projected structured light patterns in existing structured light three-dimensional endoscope projection devices, the present invention proposes a structured light three-dimensional endoscope.

[0005] The present invention is achieved through the following technical solutions:

[0006] The present invention proposes a structured light three-dimensional endoscope comprising an endoscope probe, an endoscope hose, an image processor, and a fiber optic light source, wherein:

[0007] The endoscopic probe includes a miniature camera and a metasurface fiber array projection device, wherein the miniature camera is connected to the image processor via an endoscope hose by a data cable, and the metasurface fiber array projection device includes the fiber bundle and optical fibers connected to both ends of the fiber bundle, one end of the fiber bundle is connected to the fiber light source via the endoscope hose and the optical fiber, and the surface of the optical fiber end connected to the other end of the fiber bundle is engraved with a metasurface holographic layer, and the diffraction pattern of each metasurface holographic layer corresponds to a structured light coding pattern; each optical fiber is lit in turn, and each optical fiber uses the metasurface holographic layer on its end face to project the structured light pattern to the surface of the collected object in turn, and the micro camera is used to record the deformed structured light pattern formed by the reflection of the surface of the collected object in turn, and the three-dimensional morphology of the surface of the collected object is reconstructed according to the structured light decoding algorithm.

[0008] Furthermore, the arrangement direction of the optical fibers in the metasurface optical fiber array projection device is the same as the stripe direction of the structured light pattern.

[0009] Furthermore, the metasurface optical fiber array projection device also includes a fixing plate and a gasket, and a gasket is provided between the two fixing plates. The fixing plates clamp the optical fibers and the gasket and arrange the optical fibers vertically.

[0010] Furthermore, the endoscope hose is sheathed on the outside of the data line and the optical fiber bundle, and is sealed and connected to the endoscope probe.

[0011] Furthermore, the optical fiber light source is provided with an optical switch, and the optical switch is used to light up each of the optical fibers in sequence.

[0012] Furthermore, the number of the optical fibers is the same as the number of the structured light coding patterns.

[0013] Beneficial effects of the present invention:

[0014] (1) The structured light three-dimensional endoscope proposed in the present invention uses a metasurface optical fiber array projection device to complete projection. Each of the optical fibers uses the metasurface holographic layer on its end face to project a structured light pattern onto the surface of the collected object. The surface of the collected object reflects to form a deformed structured light pattern, which is recorded in turn by the micro camera. The three-dimensional morphology of the surface of the collected object is reconstructed according to the structured light decoding algorithm. This can greatly reduce the volume of the structured light three-dimensional reconstruction device and achieve high-precision three-dimensional reconstruction of the collected object.

[0015] (2) The optical fiber arrangement direction of the metasurface optical fiber array projection device proposed in the present invention is the same as the stripe direction of the structured light pattern, which can avoid the error introduced by the misalignment of the projection spot along the optical fiber arrangement direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a diagram showing the imaging principle of the structured light three-dimensional endoscope of the present invention;

[0017] Figure 2 This is the overall structural diagram of the structured light three-dimensional endoscope of the present invention;

[0018] Figure 3 This is a schematic diagram of the connection between the micro camera, data cable and image processor;

[0019] Figure 4 Schematic diagram of the connection between the metasurface fiber array projection device and the fiber light source;

[0020] Figure 5 This is a structural diagram of the metasurface fiber array projection device;

[0021] In the figure: endoscopic probe 1, endoscopic hose 2, image processor 3, fiber optic light source 4, miniature camera 21, data cable 22, metasurface fiber array projection device 31, fiber bundle 32, optical fiber 311, metasurface holographic layer 312, fixing splint 313, gasket 314.

[0022] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0023] In order to more clearly and completely illustrate the technical solution of the present invention, the present invention will be further described below with reference to the accompanying drawings.

[0024] Please refer to Figure 1-Figure 5 The present invention proposes a structured light three-dimensional endoscope, comprising an endoscope probe 1, an endoscope hose 2, an image processor 3 and a fiber optic light source 4, wherein:

[0025] The endoscopic probe 1 includes a miniature camera 21 and a metasurface fiber array projection device 31. The miniature camera 21 is connected to the image processor 3 via the endoscope hose 2 via a data cable 22. The metasurface fiber array projection device 31 includes a fiber bundle 32 and optical fibers connected to both ends of the fiber bundle. One end of the fiber bundle 32 is connected to the fiber light source 4 via the endoscope hose 2 and the optical fiber 311. The end surface of the optical fiber 311 connected to the other end of the fiber bundle 32 is engraved with a metasurface holographic layer 312. The diffraction pattern of each metasurface holographic layer 312 corresponds to a structured light coding pattern; each optical fiber 311 is lit in turn, and each optical fiber 311 uses the metasurface holographic layer 312 on its end face to project the structured light pattern to the surface of the collected object in turn, and uses the miniature camera 21 to record the deformed structured light pattern formed by the reflection of the surface of the collected object in turn, and reconstructs the three-dimensional morphology of the surface of the collected object according to the structured light decoding algorithm.

[0026] In a specific embodiment, reference Figure 1 and Figure 2The metasurface holographic layer 312 is designed according to the structured light pattern. The light emitted by an optical fiber 311 is diffracted by a metasurface holographic layer 312 to form a structured light pattern, and the structured light pattern is projected onto the surface of the collected object, and is reflected by the surface of the collected object to the micro camera 21, and the structured light pattern projected by the optical fiber 311 is recorded. Each optical fiber 311 projects a structured light pattern in turn. After the projection of one optical fiber 311 is completed, the micro camera 21 records the corresponding deformed structured light pattern. And so on. After all optical fibers 311 are projected in turn, the three-dimensional morphology of the collected object is restored according to each deformed structured light pattern recorded by the micro camera 21 and the three-dimensional reconstruction algorithm of the structured light pattern. The present invention uses the surface of the optical fiber 311 to engrave the metasurface holographic layer 312, which can greatly reduce the volume of the structured light projection device. Each optical fiber 311 projects a structured light coding pattern, and each optical fiber 311 is lit in turn, which can achieve high-precision three-dimensional reconstruction.

[0027] Furthermore, the arrangement direction of the optical fibers 311 in the metasurface optical fiber array projection device 31 is the same as the stripe direction of the structured light pattern.

[0028] In a specific embodiment, reference Figure 1 After the optical fiber 311 is diffracted by the metasurface holographic layer 312, a structured light pattern is formed. The structured light pattern includes multiple stripes. The arrangement direction of the optical fiber 311 in the metasurface optical fiber array projection device 31 is the same as the stripe direction of the structured light pattern, which can avoid the error introduced by the misalignment of the projection spot along the arrangement direction of the optical fiber 311.

[0029] Furthermore, the metasurface fiber array projection device 31 also includes a fixed clamp 313 and a gasket 314. The gasket 314 is arranged between the two fixed clamps 313. The fixed clamp 313 clamps the optical fiber 311 and the gasket 314 and arranges the optical fiber 311 vertically (i.e., arranged along the Y-axis direction).

[0030] In a specific embodiment, reference Figure 5 , two fixed clamps 313 are arranged vertically, and a gasket 314 is clamped on the upper and lower parts of the clamps. The thickness of the gasket 314 is the same as the diameter of the optical fiber 311. The optical fiber 311 is located between the two gaskets 314. The gasket 314 and the fixed clamps 313 fix the multiple optical fibers 311 in the vertical direction (i.e., the Y-axis) and eliminate the inclination angle of each optical fiber 311 along the left and right direction (i.e., the X-axis).

[0031] Furthermore, the endoscope hose 2 is sheathed on the outside of the data line 22 and the optical fiber bundle 32 , and is sealedly connected to the endoscope probe 1 .

[0032] In a specific embodiment, reference Figure 2The endoscope hose 2 is sealed and connected to the endoscope probe 1 , and wraps the data line 22 and the optical fiber bundle 32 connected to the endoscope probe 1 .

[0033] Furthermore, the optical fiber light source 4 is provided with an optical switch, which is used to light up each optical fiber 311 in sequence.

[0034] In a specific embodiment, reference Figure 4 and Figure 1 The fiber optic light source 4 first lights up an optical fiber 311, and the light source projects a first structured light pattern through the optical fiber 311 and the metasurface holographic layer 312, and the micro camera 21 records the structured light pattern projected by the first optical fiber 311. Then the fiber optic light source 4 lights up the second optical fiber 311, and the light source projects a second structured light pattern through the optical fiber 311 and the metasurface holographic layer 312, and the micro camera 21 records the structured light pattern projected by the second optical fiber 311. This process is repeated until the nth optical fiber 311 is lit, and the micro camera 21 records the structured light pattern projected by the nth optical fiber 311. Finally, the three-dimensional surface shape of the captured object is restored based on the structured light pattern and the three-dimensional reconstruction algorithm.

[0035] Furthermore, the number of optical fibers 311 is the same as the number of structured light coding patterns.

[0036] In a specific embodiment, the time-coded structured light can select the coding pattern type according to actual conditions, such as a sinusoidal phase-shifted fringe sequence, a Gray code fringe sequence, a Gray code + phase-shifted / line-shifted fringe sequence, etc. The number n of optical fibers 311 is the same as the number of coding patterns of the time-coded structured light.

[0037] Of course, the present invention may have many other implementations. Based on this implementation, other implementations obtained by ordinary technicians in this field without any creative work are all within the scope of protection of the present invention.

Claims

1. A structured light three-dimensional endoscope, characterized in that: It includes an endoscope probe, an endoscope hose, an image processor and a fiber optic light source, wherein: The structural component includes a sealed shell, and the endoscopic probe includes a miniature camera and a metasurface fiber array projection device. The miniature camera is connected to the image processor by a data cable through an endoscope hose, and the metasurface fiber array projection device is connected to the fiber light source by an optical fiber bundle through an endoscope hose. The metasurface fiber array projection device includes multiple optical fibers, and the surface of the optical fiber end is engraved with a metasurface holographic layer. The diffraction pattern of each metasurface holographic layer corresponds to a structured light coding pattern; each optical fiber is lit in turn, and each optical fiber uses the metasurface holographic layer on its end face to project the structured light pattern to the surface of the collected object in turn, and uses the miniature camera to record the deformed structured light pattern formed by the reflection of the collected object surface in turn, and reconstructs the three-dimensional morphology of the collected object surface according to the structured light decoding algorithm.

2. The structured light three-dimensional endoscope according to claim 1, characterized in that: The arrangement direction of the optical fibers in the metasurface optical fiber array projection device is the same as the stripe direction of the structured light pattern.

3. The structured light three-dimensional endoscope according to claim 1, characterized in that: The metasurface optical fiber array projection device also includes a fixing plate and a gasket. A gasket is provided between the two fixing plates. The fixing plates clamp the optical fibers and the gasket and allow the optical fibers to be arranged vertically.

4. The structured light three-dimensional endoscope according to claim 1, characterized in that: The endoscope hose is sheathed on the outside of the data line and the optical fiber bundle, and is sealed and connected to the endoscope probe.

5. The structured light three-dimensional endoscope according to claim 1, characterized in that: The optical fiber light source is provided with an optical switch, and the optical switch is used to light up each of the optical fibers in sequence.

6. The structured light three-dimensional endoscope according to claim 1, characterized in that: The number of the optical fibers is the same as the number of the structured light coding patterns.

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