Pneumatic endoscopic rotating device and method with angular displacement detection function

Abstract

The invention belongs to the technical field of optical detection, and discloses a pneumatic endoscopic rotating device with a coding function and a method. The rotating part is used for driving an optical element at the front end of the endoscopic probe to rotate; in the angular displacement detection part, a periodic coding structure is arranged around the inner wall of a glass inner tube of the endoscopic probe by a circle; the coding structure has distinguishable optical characteristics at different angle positions; the light source is used for emitting detection light to the coding structure and receiving reflected light, and decoding the coding structure through interference or other optical modes so as to obtain rotation angle information; and the correction part is used for correcting the rotation imaging data based on the rotation angle information so as to obtain an imaging result of uniform-speed scanning. The spectral domain white light interference technology is adopted to synchronously scan the coding structure, the problems that uniform-speed scanning imaging and rotation angle determining cannot be achieved are solved through coding signals, and dual guarantee of positioning precision and imaging quality is achieved.

Description

Technical Field

[0001] This invention relates to the field of optical detection technology, and specifically to a pneumatic endoscopic rotating device and method with angular displacement detection function. Background Technology

[0002] In endoscopic imaging, such as OCT endoscopes, photoacoustic endoscopes, and ultrasound endoscopes, it is usually necessary to drive a probe light or probe ultrasound for rotational scanning. Miniaturizing this drive system is very difficult in endoscopic imaging, especially for vascular imaging, where the probe needs to be around 1mm in size. Common motor rotation methods fall into two categories: the motor is located inside the probe, and the motor is located outside the probe. An external motor with a torsion shaft drives the rotation, while a motor located outside the probe drives the rotating part at the probe tip via a torsion shaft. The advantage is that the motor size does not limit the probe size, but the disadvantage is that the shaft length may lead to uneven rotation. A built-in micromotor, where a micromotor is packaged at the probe tip to directly drive the rotation of optical elements or transducers, has the disadvantages of being difficult to miniaturize, having high manufacturing costs, and complex packaging. Furthermore, during motor operation, vibration and noise are easily generated due to fluctuations in electromagnetic force and friction between mechanical transmission components, affecting operational stability and thus interfering with image quality. To avoid cross-infection, many clinical applications require disposable probes, but both of these methods are relatively expensive.

[0003] The patent "Photoacoustic Adjustable Focus Endoscopic Imaging Device and Imaging Method Based on Temperature-Controlled Memory Alloy" (CN202411136084) uses a photoelectric slip ring connected to the probe support structure outside the probe to drive its rotation. However, the coaxiality error between the slip ring and the electric slip ring can cause unstable signal transmission. Furthermore, contact interference from the electric slip ring and electromagnetic interference from the transmission signal lines during rotation can affect the imaging results.

[0004] The patent "An Endoscope with Limitless Rotation" (CN202322550520) features a motor mounted on a fixed base inside the intermediate housing. Limitless rotation is achieved through the cooperation of the motor, probe ring, and rotating probe brush. However, the parallel installation of the motor and probe ring occupies space, preventing further reduction in the size of the intermediate housing. The modular design of multiple components does not take into account integration, resulting in overall structural redundancy. Summary of the Invention

[0005] To overcome the limitations of existing endoscopic drive technology, this invention proposes a pneumatic endoscopic rotation device and method with angular displacement detection function.

[0006] The technical solution of the present invention is as follows: An endoscopic rotation device with angular displacement detection function, comprising:

[0007] The rotating part is used to drive the optical elements at the tip of the endoscope probe to rotate;

[0008] The angular displacement detection section is used to emit probe light to the angular displacement detection structure and receive reflected light, and to perform angular displacement detection on the angular displacement detection structure by interference or other optical methods to obtain rotation angle information.

[0009] A periodic angular displacement detection structure is provided around the inner or outer wall of the glass inner tube of the endoscopic probe; the angular displacement detection structure has distinguishable optical features at different angular positions;

[0010] The correction section is used to correct the rotational imaging data based on the rotation angle information to obtain uniform scanning and imaging results for each revolution. The optical features are differences in reflectivity, differences in transmittance, contrast between light and dark, or height differences.

[0011] When the optical feature is a contrast between light and dark, the angular displacement detection structure consists of alternating high-reflection and low-reflection areas.

[0012] When the optical feature is a difference in light transmittance, the angular displacement detection structure consists of alternating transparent and opaque areas.

[0013] When the optical feature is a height difference, the angular displacement detection structure is a stepped distribution with different widths.

[0014] When the optical feature is a difference in reflectivity, the angular displacement detection structure can use materials with different reflectivity, resulting in different brightness levels of reflected light and forming encoded signals with different intensities.

[0015] The angular displacement detection structure is formed by a periodic distribution of steps of varying heights around the inner glass tube; the width of the step serving as the starting marker is different from that of the other steps.

[0016] The angular displacement detection section is a spectral domain interferometry system, including a white light source 19, a circulator 20, a coupler 21, a computer 22, a spectrometer 23, and a reference arm 24. The light emitted by the white light source 19 enters the coupler 21 through the circulator 20 and is split into two paths: a reference light and a sample light. The reflected sample light returns along the original optical path. In the sample arm optical path, it enters the endoscope probe through the optical fiber 5 to perform the above operations. The sample arm return light and the reference arm return light return to the circulator 20 and then enter the spectrometer 23. The spectrometer 23 records the interference spectrum, which is then sent to the computer 22 for further demodulation of the spectral signal.

[0017] The rotating part is pneumatically driven and includes an air intake pipe 1, a spiral wheel 10, and a fixed shaft;

[0018] An air inlet pipe 1 is opened at one end of the inner glass tube 3; the spiral wheel 10 and the fixed shaft are both located inside the inner glass tube 3; the fixed shaft is divided into a fixed shaft a4 and a fixed shaft b12, which are located at both ends inside the inner glass tube 3 respectively; one end of the fixed shaft b12 includes a conical part 11, and the bottom of the spiral wheel 10 is embedded in the conical part; the inner glass tube 3 is connected to the outer glass tube 13; a number of vent holes 2 are provided on one end of the outer glass tube 13;

[0019] An air compressor drives a spiral wheel 10 to rotate. The spiral wheel 10 is connected in sequence to a beam splitter 9 and a dichroic beam splitter 8, causing the dichroic beam splitter 8 and the beam splitter 9 to rotate synchronously. This allows the light reflected by the beam splitter 9 and the dichroic beam splitter 8 to perform a circular scan. The light reflected by the angular displacement detection structure and the sample returns to the spectral domain interferometry system 15 and the endoscopic imaging system 16 through the original path, thus realizing imaging of the angular displacement detection structure and the sample.

[0020] Air enters the inner glass tube through the air inlet pipe 1, travels from the fixed shaft a4 to the fixed shaft b12, flows out from the inner glass tube 3 to the outer glass tube 13, and is then discharged through the vent 2.

[0021] An endoscopic rotation correction method based on an angular displacement detection structure, implemented using an endoscopic rotation device with angular displacement detection function, includes the following steps:

[0022] Acquire the angular displacement signal of the angular displacement detection structure during one revolution;

[0023] The range of each circle is determined based on the starting position signal of the angular displacement signal;

[0024] The sampling points within each period are uniformly corrected to generate an angle sequence with an equal angle distribution;

[0025] The rotation angle of the endoscopic imaging signal is corrected based on the angular displacement signal to obtain imaging data with uniform rotation.

[0026] The signal boundary is determined by the contrast of the angular displacement signal. First, the range of each circle is determined based on the characteristics of the starting position signal of the angular displacement signal. The signal within each circle is processed, and the sub-cycle is divided with the rising edge or the maximum value as the boundary. This represents the angular distribution within each sub-cycle; m represents the order of the sub-cycles, and there are a total of M sub-cycles; This indicates the order of the scan points within this sub-cycle; L indicates that there are L scan points in this sub-cycle.

[0027] Make corrections for each sub-cycle;

[0028] Based on the angular displacement signal of the spectral domain interferometer system, periodic corrections are performed, with the angle of each sub-period being... Assuming that the scan points within each sub-cycle are equally spaced, the angle range of each sub-cycle is corrected to... ;

[0029] Starting from the first sub-cycle, each value in the first sub-cycle is corrected, as shown in formula (1):

[0030] , (1)

[0031] Based on the first sub-cycle, each value in the second sub-cycle is modified, as shown in formula (2):

[0032] , (2)

[0033] The values ​​for the last sub-cycle are adjusted sequentially, as shown in formula (3):

[0034] , (3)

[0035] Angle coordinates of M sub-cycles , merge to form a new angle sequence ;

[0036] The endoscopic imaging system and the spectral interferometry system acquire signals synchronously. It refers to the scanning angle of the endoscopic imaging system, based on The coordinates of the imaging results from the endoscopic imaging system are adjusted to obtain imaging results from uniform scanning.

[0037] The beneficial effects of this invention are:

[0038] 1. The endoscopic probe achieves miniaturization by compactly integrating the rotation drive, reflection imaging and angular displacement detection structure. The pneumatic rotation module has the advantages of simple structure, low friction, low vibration and noise, good stability and fast response speed, which can adapt to narrow endoscopic environments and meet the needs of rapid imaging.

[0039] 2. The spectral domain white light interferometry technique is used to scan the angular displacement detection structure synchronously. By detecting the angular displacement in real time, the problems of difficulty in confirming the starting position of pneumatically driven rotation, inability to scan and image at a uniform speed, and inability to determine the rotation angle are solved, thus achieving dual assurance of positioning accuracy and imaging quality.

[0040] 3. Core components are manufactured using 3D printing technology, achieving the smallest endoscopic drive structure at a low cost compared to traditional disposable endoscopic probe designs. Attached Figure Description

[0041] Figure 1This is a schematic diagram of an endoscopic probe;

[0042] Figure 2 This is a schematic diagram of a spectral domain white light interferometer system;

[0043] Figure 3 This is a schematic comparison diagram of the imaging results of the glass inner tube wall angular displacement detection structure and the spectral domain interferometry system.

[0044] In the figure: 1-Inlet pipe, 2-Ventilation hole, 3-Inner glass tube, 4-Fixed axis a, 5-Fiber optic cable, 6-Coreless fiber optic cable, 7-Gradient refractive index fiber optic cable, 8-Dichroic beam splitter, 9-Beam splitter, 10-Spiral wheel, 11-Cone, 12-Fixed axis b, 13-Outer glass tube, 14-Wavelength division multiplexer, 15-Spectral domain interferometry system, 16-Endoscopic imaging system, 17-Sample, 18-Angular displacement detection structure. Detailed Implementation

[0045] An endoscopic rotation device with angular displacement detection function includes:

[0046] The rotating part is used to drive the optical elements at the tip of the endoscope probe to rotate;

[0047] In the angular displacement detection section, a periodic angular displacement detection structure is arranged around the inner or outer wall of the glass inner tube of the endoscopic probe; the angular displacement detection structure has distinguishable optical features at different angular positions;

[0048] The angular displacement detection section is used to emit probe light to the angular displacement detection structure and receive reflected light, and to perform angular displacement detection on the angular displacement detection structure by interference or other optical methods to obtain rotation angle information.

[0049] The correction section is used to correct the rotation imaging data based on the rotation angle information to obtain the imaging result of uniform scanning.

[0050] Furthermore, the optical features can be differences in reflectivity, differences in light transmittance, contrast between light and dark, or height differences.

[0051] Furthermore, when the optical feature is a contrast between light and dark, the angular displacement detection structure consists of alternating high-reflection and low-reflection areas.

[0052] Furthermore, when the optical feature is a difference in light transmittance, the angular displacement detection structure consists of alternating transparent and opaque areas.

[0053] Furthermore, when the optical feature is a height difference, the angular displacement detection structure is a step distribution with different widths.

[0054] Furthermore, when the optical feature is a height difference, the angular displacement detection structure is a stepped distribution with alternating heights. Adjacent steps of varying heights form a group, each group having the same total width; one group serves as the starting point of the circle, called the starting group, and the proportion of steps of varying heights in the starting group differs from that in the other groups.

[0055] The angular displacement detection section is a spectral domain interferometry system, including a white light source 19, a circulator 20, a coupler 21, a computer 22, a spectrometer 23, and a reference arm 24. The light emitted by the white light source 19 enters the coupler 21 through the circulator 20 and is split into two paths: a reference light and a sample light. The reflected sample light returns along the original optical path. In the sample arm optical path, it enters the endoscope probe through the optical fiber 5 to perform the above operations. The sample arm return light and the reference arm return light return to the circulator 20 and then enter the spectrometer 23. The spectrometer 23 records the interference spectrum, which is then sent to the computer 22 for further demodulation of the spectral signal.

[0056] The rotating part is pneumatically driven and includes an air intake pipe 1, a spiral wheel 10, and a fixed shaft;

[0057] An air inlet pipe 1 is opened at one end of the inner glass tube 3; the spiral wheel 10 and the fixed shaft are both located inside the inner glass tube 3; the fixed shaft is divided into a fixed shaft a4 and a fixed shaft b12, which are located at both ends inside the inner glass tube 3 respectively; the other end of the inner glass tube 3 is connected to the other end of the outer glass tube 13; a number of vent holes 2 are provided on one end of the outer glass tube 13.

[0058] An air compressor drives a spiral wheel 10 to rotate. The spiral wheel 10 is connected in sequence to a beam splitter 9 and a dichroic beam splitter 8, causing the dichroic beam splitter 8 and the beam splitter 9 to rotate synchronously. This allows the light reflected by the beam splitter 9 and the dichroic beam splitter 8 to perform a circular scan. The light reflected by the angular displacement detection structure and the sample returns to the spectral domain interferometry system 15 and the endoscopic imaging system 16 through the original path, thus achieving imaging of the angular displacement detection structure and the sample.

[0059] Air enters the inner glass tube through the air inlet pipe 1, travels from the fixed shaft a4 to the fixed shaft b12, flows out from the inner glass tube 3 to the outer glass tube 13, and is then discharged through the vent 2.

[0060] Endoscopic probe structure as follows Figure 1 As shown, the overall structure of the probe consists of two parts: an outer glass tube 13 and an inner glass tube 3. From left to right, the inner glass tube 3 comprises a fixed shaft a4, an optical fiber 5, a coreless optical fiber 6, a gradient refractive index optical fiber 7, a dichroic beam splitter 8, a beam splitter 9, a spiral wheel 10, a cone 11, and a fixed shaft b12. The cone 11 and the fixed shaft b12 are connected together, and the cone is embedded in the bottom of the spiral wheel, which stabilizes the center of the spiral wheel and reduces friction. The function of the outer glass tube 13 is to discharge the gas from the inner glass tube 3.

[0061] The probe light of the imaging system and the probe light of the spectral domain interferometer are combined by wavelength division multiplexer 14 and enter fiber 5. After entering fiber 5, the light is transmitted through coreless fiber 6 and gradient refractive index fiber 7 in sequence, and finally projected onto the mirror surface of dichroic beam splitter 8.

[0062] The detection light of the imaging system 16 is reflected by the dichroic beam splitter 8 and reflected to the surrounding sample 17. The reflected sample light returns to the imaging system 16 along the original path.

[0063] The probe light of the spectral domain interferometer system passes through the dichroic beam splitter 8 and is reflected by the beam splitter 9 to the angular displacement detection structure on the inner wall 18 of the glass inner tube. The sample light reflected by the angular displacement detection structure returns to the spectral domain interferometer system 15 along the original path to perform angular displacement detection. The angular displacement detection structure 18 is located on the inner or outer wall of the glass inner tube near the beam splitter 9, along the circumferential direction.

[0064] The optical fiber 5 is fixed by means of the fixed shaft a4 via the vent plug 2;

[0065] An air compressor drives a spiral wheel 10 to rotate. The spiral wheel 10 is connected to a dichroic beam splitter 8 and a beam splitter 9, thereby driving the dichroic beam splitter 8 and the beam splitter 9 to rotate synchronously to complete imaging. Air enters the glass tube through the air inlet pipe 1, travels from the fixed axis a4 to the fixed axis b12, flows out from the inner glass tube 3 to the outer glass tube 13, and is then discharged from the vent 2.

[0066] A cone 11 is added between the helical wheel 10 and the fixed shaft b12 to reduce the friction between the helical wheel 10 and the fixed shaft b12, and to allow for center calibration of the helical wheel.

[0067] The angular displacement detection function is achieved by the light passing through the dichroic beam splitter 8 and being reflected by the beam splitter 9 onto the inner wall of the glass tube. At the position where the light spot illuminates the inner wall of the glass tube, there are angular displacement detection structures 18 with different heights around the perimeter. The light reflected by the angular displacement detection structures 18 returns to the wavelength division multiplexer 14 and enters the spectral domain white light interferometer system 15. The spectral domain white light interferometer system 15 is used to calculate the optical path difference at different angles, image the angular displacement detection structure, and calculate the rotation angle based on the imaging result of the angular displacement detection structure, thereby achieving positioning.

[0068] Spectral domain white light interferometry system 15 Figure 2 As shown, the light emitted from the white light source 19 enters the coupler 21 through the circulator 20 and is split into two paths: a reference light and a sample light. The reflected sample light returns along the original optical path. In the sample arm optical path, it enters the endoscope probe through the optical fiber 5 to perform the above operations. Afterwards, the return light from the sample arm and the return light from the reference arm return to the circulator 20 and then enter the spectrometer 23. The spectrometer 23 records the interference spectrum, which is then sent to the computer 22 for further demodulation of the spectral signal.

[0069] As shown in one embodiment, the angular displacement detection structure is displayed in a stepped distribution; the angular displacement detection structure on the inner wall of the endoscopic glass is as follows. Figure 3 As shown in (a), the steps are arranged in a series of varying heights around the perimeter. The first step has a larger width. The steps behind are narrower. ,in They have the same periodic distribution.

[0070] The spectral domain white light interferometry system samples at equal periods to obtain the imaging results of the angular displacement detection structure, such as... Figure 3 As shown in (b). Based on the imaging results, the data from the rotating scan is processed, including: (1) period division, and (2) uniform sampling processing within the period.

[0071] Using a step with a width of L0 as the starting point feature of a cycle, and taking advantage of its difference from other steps, the imaging starting point can be accurately located, and the scanning data of a cycle can be located to complete a cycle of imaging.

[0072] The spectral domain white light interferometer system samples at equal periods. However, due to the inhomogeneity of the rotating imaging system, the steps of the angular displacement detection structure calculated by the spectral domain white light interferometer system have the same inhomogeneity.

[0073] The acquired imaging results are segmented, with the rising edge of the result serving as the boundary to divide into sub-periods, such as... Figure 3 As shown in (b). This represents the angular distribution within each sub-cycle, where m represents the order of the sub-cycles, and there are a total of M sub-cycles. This indicates the order of scan points within this sub-cycle, where L represents the number of scan points in this sub-cycle. Corrections are made for each sub-cycle.

[0074] Because the angular displacement detection results are uniformly periodic, assuming uniform rotation scanning, the imaging result of the spectral domain white light interferometry system is also uniformly periodic. However, since the speed of the pneumatically driven rotation is uncontrollable, the imaging result of the spectral domain white light interferometry system is non-uniformly periodic. Therefore, this invention performs uniformly periodic correction based on the imaging result of the spectral domain white light interferometry system, with the angle of each sub-period being... Assuming that the scan points within each sub-cycle are equally spaced, the angle range of each sub-cycle is corrected to... .

[0075] Starting from the first sub-cycle, each value in the first sub-cycle is corrected, as shown in formula (1):

[0076] , (1)

[0077] Based on the first sub-cycle, each value in the second sub-cycle is modified, as shown in formula (2):

[0078] , (2)

[0079] The values ​​for the last sub-cycle are adjusted sequentially, as shown in formula (3):

[0080] , (3)

[0081] Angle coordinates of M sub-cycles , merge to form a new angle sequence .

[0082] The rotating imaging system and the spectral domain white light interferometry system acquire signals synchronously, therefore It refers to the scanning angle of the rotating imaging system, based on By adjusting the coordinates of the imaging results from the rotating imaging system, an imaging result close to that of a uniform scanning motion can be obtained.

[0083] The apparatus and method of the present invention have the following functions:

[0084] 1. Probe Miniaturization: A smaller pneumatically driven endoscopic rotation device was designed. By compactly integrating the rotation drive structure, reflective imaging structure, and angular displacement detection structure, the overall size of the endoscopic probe is significantly reduced while ensuring rotational performance and angular displacement detection functionality, making it adaptable to more confined endoscopic environments. The rotating part has a simple structure, minimal friction between moving parts, extremely low vibration and noise during operation, and good stability. It can reach the set rotational speed in a very short time, with extremely fast response speed, meeting the requirements of rapid imaging.

[0085] 2. Adding an angular displacement detection and positioning device: The core problem with pneumatic drive is the difficulty in controlling the rotation angle, making it impossible to achieve uniform speed scanning imaging and determine the rotation angle. This invention uses spectral domain white light interferometry to synchronously scan the angular displacement detection structure. By correcting the scanning imaging results with real-time measured angular displacement signals, the angular information of the rotational scanning imaging results can be obtained, achieving dual assurance of positioning accuracy and imaging quality.

[0086] 3. Low-cost implementation: Compared with the disposable design commonly used in traditional endoscope probes, this probe uses 3D printing technology to manufacture core components, achieving the smallest endoscope drive structure to date with a low-cost solution.

Claims

1. An endoscopic rotation device with angular displacement detection function, characterized in that, include: The rotating part is used to drive the optical elements at the tip of the endoscope probe to rotate; The angular displacement detection section is used to emit probe light to the angular displacement detection structure and receive reflected light, and to perform angular displacement detection on the angular displacement detection structure by interference or other optical methods to obtain rotation angle information. A periodic angular displacement detection structure is provided around the inner or outer wall of the glass inner tube of the endoscopic probe; the angular displacement detection structure has distinguishable optical features at different angular positions; The correction section is used to correct the rotation imaging data based on the rotation angle information to obtain uniform scanning and imaging results for each revolution.

2. The endoscopic rotation device with angular displacement detection function according to claim 1, characterized in that, The optical characteristics are differences in reflectivity, differences in light transmittance, contrast between light and dark, or height differences.

3. The endoscopic rotation device with angular displacement detection function according to claim 2, characterized in that, When the optical feature is a contrast between light and dark, the angular displacement detection structure consists of alternating high-reflection and low-reflection areas.

4. The endoscopic rotation device with angular displacement detection function according to claim 2, characterized in that, When the optical feature is a difference in light transmittance, the angular displacement detection structure consists of alternating transparent and opaque areas.

5. The endoscopic rotation device with angular displacement detection function according to claim 2, characterized in that, When the optical feature is a height difference, the angular displacement detection structure is a stepped distribution with different widths.

6. The pneumatic endoscopic rotating device with angular displacement detection function according to claim 5, characterized in that, The angular displacement detection structure is formed by a periodic distribution of steps of varying heights around the inner glass tube; the width of the step serving as the starting marker is different from that of the other steps.

7. The endoscopic rotation device with angular displacement detection function according to claim 1, characterized in that, The angular displacement detection section is a spectral domain interferometry system, including a white light source (19), a circulator (20), a coupler (21), a computer (22), a spectrometer (23), and a reference arm (24). The light emitted by the white light source (19) enters the coupler (21) through the circulator (20) and is split into two paths, namely the reference light and the sample light. The reflected sample light returns along the original optical path. In the sample arm optical path, it enters the endoscope probe through the optical fiber (5) to perform the above operation. The sample arm return light and the reference arm return light return to the circulator (20) and then enter the spectrometer (23). The spectrometer (23) records the interference spectrum and hands it over to the computer (22) for further demodulation of the spectral signal.

8. The endoscopic rotation device with angular displacement detection function according to claim 1, characterized in that, The rotating part is pneumatically driven and includes an air intake pipe (1), a spiral wheel (10), and a fixed shaft; An air inlet pipe (1) is opened at one end of the inner glass tube (3); the spiral wheel (10) and the fixed shaft are both located inside the inner glass tube (3); the fixed shaft is divided into a fixed shaft a (4) and a fixed shaft b (12), which are located at both ends inside the inner glass tube (3); one end of the fixed shaft b (12) includes a conical part (11), and the bottom of the spiral wheel (10) is embedded in the conical part; the inner glass tube (3) is connected to the outer glass tube (13); a number of ventilation holes (2) are provided on one end of the outer glass tube (13); An air compressor drives a spiral wheel (10) to rotate. The spiral wheel (10) is connected in sequence to a beam splitter (9) and a dichroic beam splitter (8), which drives the dichroic beam splitter (8) and the beam splitter (9) to rotate synchronously. This allows the light reflected by the beam splitter (9) and the dichroic beam splitter (8) to perform a circular scan. The light reflected by the angular displacement detection structure and the sample returns to the spectral interference system (15) and the endoscopic imaging system (16) through the original path, thus realizing the imaging of the angular displacement detection structure and the sample. Air enters the inner glass tube through the air inlet pipe (1), travels from fixed shaft a (4) to fixed shaft b (12), flows out from the inner glass tube (3) to the outer glass tube (13), and is then discharged from the vent (2).

9. An endoscopic rotation correction method based on an angular displacement detection structure, characterized in that, This is achieved using an endoscopic rotation device with angular displacement detection function as described in any one of claims 1-8, comprising the following steps: Acquire the angular displacement signal of the angular displacement detection structure during one revolution; The range of each circle is determined based on the starting position signal of the angular displacement signal; The sampling points within each period are uniformly corrected to generate an angle sequence with an equal angle distribution; The rotation angle of the endoscopic imaging signal is corrected based on the angular displacement signal to obtain imaging data with uniform rotation.

10. The endoscopic rotation correction method based on an angular displacement detection structure according to claim 9, characterized in that, The signal boundary is determined by the contrast of the angular displacement signal. First, the range of each circle is determined based on the characteristics of the starting position signal of the angular displacement signal. The signal within each circle is processed, and the sub-cycle is divided with the rising edge or the maximum value as the boundary. This represents the angular distribution within each sub-cycle; m represents the order of the sub-cycles, and there are a total of M sub-cycles; This indicates the order of the scan points within this sub-cycle; L indicates that there are L scan points in this sub-cycle. Make corrections for each sub-cycle; Based on the angular displacement signal of the spectral domain interferometer system, periodic corrections are performed, with the angle of each sub-period being... Assuming that the scan points within each sub-cycle are equally spaced, the angle range of each sub-cycle is corrected to... ; Starting from the first sub-cycle, each value in the first sub-cycle is corrected, as shown in formula (1): ， (1) ； Based on the first sub-cycle, each value in the second sub-cycle is modified, as shown in formula (2): ， (2) ； The values ​​for the last sub-cycle are adjusted sequentially, as shown in formula (3): ， (3) ； Angle coordinates of M sub-cycles , merge to form a new angle sequence ; The endoscopic imaging system and the spectral interferometry system acquire signals synchronously. It refers to the scanning angle of the endoscopic imaging system, based on The coordinates of the imaging results from the endoscopic imaging system are adjusted to obtain imaging results from uniform scanning.

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