Refraction-reflection type cell microendoscope imaging system and cell microendoscope
By using a catadioptric cellular microendoscopic imaging system, aberrations are corrected by using a reflective mirror and symmetrical lens assembly, which solves the accuracy and cost problems caused by mechanical zoom in existing technologies, and realizes low-cost, stable cell-level imaging and narrow cavity observation.
Patent Information
- Application Number
- CN202511952772.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-23
- Publication Date
- 2026-05-15
AI Technical Summary
In the existing technology, cell microendoscopy relies on a precision mechanical drive mechanism for focusing, which leads to decreased repeatability, high operational difficulty, complex structure, high cost, and the inability to be used once, thus limiting its application in narrow cavities.
The system employs a catadioptric cellular microendoscopic imaging system, which uses a reflector to refract light and combines it with a symmetrical lens assembly to correct aberrations in off-axis imaging, achieving super-resolution imaging without the need to move the lens and eliminating the need for traditional mechanical zoom mechanisms.
It achieves stable cell-level image acquisition, reduces costs, avoids the risk of cross-infection, and can enter narrower cavities, simplifying the operation process.
Smart Images
Figure CN122043721A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of optical technology, and more specifically, to a cell microendoscopic imaging system and a cell microendoscopic endoscope. Background Technology
[0002] In existing technologies, to achieve cell-level in vivo microscopic imaging at the "optical biopsy" level, mainstream solutions rely on variable-focus micro-objective systems: continuously focusing between wide-angle and close-up modes using one or more sets of movable lenses. However, such solutions require a precision mechanical drive mechanism (such as a guide wire, micromotor / MEMS, etc.) built into a micro-lens (composed of different lens groups) at a relatively limited diameter distal end to drive relative movement of different lens groups within the lens to achieve the zoom function. This approach leads to three drawbacks: firstly, the mechanical drive mechanism suffers from reduced accuracy in repositioning due to metal fatigue and return gaps, resulting in a higher probability of "defocusing"; secondly, the need for synchronous control of different lens groups increases the difficulty of operation for doctors, requiring frequent focusing and switching between wide-angle and close-up modes to observe multiple areas, significantly extending the surgical time; and thirdly, such continuously focusing endoscopes have complex structures, numerous parts, and high costs per unit, making them unusable for single use and posing a risk of cross-infection with repeated use. Furthermore, due to the need for a built-in precision mechanical drive mechanism, its diameter is difficult to reduce further, limiting its application in ultra-fine cavities such as pulmonary surgery, neurosurgery, and pancreatic and biliary ducts.
[0003] Therefore, there is an urgent need for an endoscopic imaging architecture that does not require mechanical zoom, has a simpler structure, and can be integrated into a single endoscope body to promote the widespread use of optical biopsy. Summary of the Invention
[0004] The purpose of this invention is to provide a refractory cell microscopic endoscope imaging system and a refractory cell microscopic endoscope to solve the problem that the existing endoscope structure for cell microscopic in vivo imaging relies on a built-in precision mechanical drive mechanism for continuous focusing. This simplifies the endoscope structure and enables stable acquisition of cell-level images in a single, low-cost manner.
[0005] According to one aspect of the present invention, a catadioptric cellular microendoscopic imaging system is provided, comprising: a lens assembly having at least two lenses; a protective cover plate located between the lens assembly and the surface of the tissue being observed, wherein light from the surface of the tissue being observed passes through the protective cover plate and enters the lens assembly; an image sensor for converting optical signals into electrical signals, wherein the image sensor and the protective cover plate are located on the same side of the lens assembly; and a reflector located on the other side of the lens assembly, the reflector being coaxial with the lens assembly, the reflector reflecting light passing through the protective cover plate to the image sensor; wherein the protective cover plate and the image sensor are arranged symmetrically with respect to the axis of the lens assembly; light from the surface of the tissue being observed, after passing through the protective cover plate and the lens assembly, is reflected by the reflector and passes through the lens assembly again, ultimately forming an image on the image sensor.
[0006] Optionally, at least one lens in the lens assembly is an aspherical lens.
[0007] Optionally, the lens assembly further includes a filter located on the side of the lens assembly closest to the reflector.
[0008] Optionally, the lens assembly is disposed in the first lens barrel, and the reflector is disposed in the second lens barrel. The first lens barrel and the second lens barrel are connected by threads to adjust the distance between the lens assembly and the reflector.
[0009] Optionally, the first lens barrel is a trumpet-shaped structure with an inner diameter that gradually increases along the optical axis, and the diameter of each lens in the lens assembly gradually increases along the optical axis from the surface of the observed tissue to the reflecting mirror.
[0010] Optionally, the reflector includes an aspherical concave reflector.
[0011] Optionally, the image sensor is either CMOS or CCD.
[0012] Optionally, the lens assembly includes a first lens, a second lens, a third lens, and a fourth lens, arranged sequentially along the optical axis of the reflector from the protective cover to the reflector. The first lens is a biconvex lens, with a convex first surface and a convex second surface opposite to the first surface. The second lens is a convex-concave lens, with a convex first surface and a concave second surface opposite to the first surface. The third lens is a concave-convex lens, with a concave first surface and a convex second surface opposite to the first surface. The fourth lens is a convex-concave lens, with a convex first surface and a concave second surface opposite to the first surface.
[0013] Optionally, the lens assembly includes a first lens, a second lens, a third lens, a fourth lens, and a fifth lens, arranged sequentially along the axis of the reflector from the protective cover to the reflector. The first lens is a biconvex lens, with a convex first surface and a convex second surface opposite to the first surface. The second lens is a biconcave lens, with a concave first surface and a concave second surface opposite to the first surface. The third lens is a concave-convex lens, with a concave first surface and a convex second surface opposite to the first surface. The fourth lens is a concave-convex lens, with a concave first surface and a convex second surface opposite to the first surface. The fifth lens is a biconcave lens, with a concave first surface and a concave second surface opposite to the first surface.
[0014] Optionally, the lens assembly includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens. The first lens, the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens are arranged sequentially along the axis of the reflector from the protective cover to the reflector. The first lens is a convex-concave lens, with a convex first surface and a concave second surface opposite to the first surface. The second lens is a concave-convex lens, with a concave first surface and a convex second surface opposite to the first surface. The third lens is a convex-concave lens, with a convex first surface and a concave second surface opposite to the first surface. The fourth lens is a convex-concave lens, with a convex first surface and a concave second surface opposite to the first surface. The fifth lens is a concave-convex lens, with a concave first surface and a convex second surface opposite to the first surface. The sixth lens is a biconcave lens, with a concave first surface and a concave second surface opposite to the first surface.
[0015] According to another aspect of the present invention, a cell microendoscopy is provided, comprising: a close-range lens formed by the above-described catadioptric cell microendoscopy imaging system, the close-range lens being disposed at the distal end of the cell microendoscopy body.
[0016] Optionally, the cell microendoscopy is a disposable instrument or a reusable cell microendoscopy.
[0017] The refracting cellular microendoscopic imaging system and cellular microendoscopic endoscope provided by this invention refract light through a reflector and correct aberrations in off-axis imaging using a symmetrical lens assembly, completely eliminating the need for the micro-mechanical focusing mechanism required in traditional cellular endoscopes. In this cellular microendoscopic imaging system, light obtained from the surface of the observed tissue through the protective cover slip travels twice through the same lens assembly, automatically canceling coma, distortion, and transverse chromatic aberration using a nearly symmetrical optical path, thereby achieving super-resolution imaging. It meets the resolution requirements of close-range "optical biopsy" without moving any lens in the lens assembly, fundamentally eliminating frequent focusing operations and the risk of defocusing due to metal fatigue, return gaps, etc., resulting in higher reliability and stability.
[0018] Furthermore, the cell microscopic endoscope provided by the present invention includes a folding-back endoscope imaging system as described above that can perform cell microscopic observation. By closely attaching the protective cover at the distal end of the endoscope to the target area, the surface of the tissue being observed is in close contact with the outer surface of the protective cover, thereby performing cell microscopic observation to meet the needs of cell-level "optical biopsy".
[0019] By employing this folding-back cellular microendoscopic imaging system, the distal end of the endoscope no longer needs to accommodate the traction guide wire, micromotor, or other driving components required for focusing. This reduces the diameter of the endoscope, allowing it to directly enter and observe narrower cavities. The cellular microendoscopic imaging system of this invention is inexpensive, economical for single-use applications, and completely avoids the cross-contamination problems that can result from repeated use. Attached Figure Description
[0020] The above and other objects, features and advantages of the present invention will become clearer from the following description of embodiments of the invention with reference to the accompanying drawings.
[0021] Figure 1 A schematic diagram illustrating the first principle of the foldback cell microendoscopic imaging system of the present invention is shown.
[0022] Figure 2 This diagram illustrates the second principle of the foldback cell microendoscopic imaging system of the present invention.
[0023] Figure 3 A schematic diagram of the foldback cell microendoscopic imaging system according to a first embodiment of the present invention is shown;
[0024] Figure 4 This diagram illustrates the assembly structure of the folding-back cell microendoscopic imaging system according to a first embodiment of the present invention.
[0025] Figure 5A schematic diagram of the foldback cell microendoscopic imaging system according to a second embodiment of the present invention is shown;
[0026] Figure 6 A schematic diagram of a foldback cell microendoscopic imaging system according to a third embodiment of the present invention is shown. Detailed Implementation
[0027] The invention will now be described in more detail with reference to the accompanying drawings. In the various drawings, the same reference numerals are used to denote the same parts. For clarity, the various parts in the drawings are not drawn to scale. Furthermore, some well-known parts may not be shown.
[0028] It should be understood that when describing a structure, when referring to a layer, region, or component as being "above" or "on top of" another layer, region, or component, it can mean that it is directly above the other layer, region, or component, or that there are other layers or structures between it and the other layer, region, or component. Furthermore, if flipped, the layer, region, or component will be located "below" or "under" the other layer, region, or component.
[0029] In order to describe a situation that is directly above another layer, another area, or another component, this article will use the expressions "directly above" or "above and adjacent to".
[0030] Many specific details, such as the structure, materials, dimensions, processing methods, and techniques of components, are described below in order to provide a clearer understanding of the invention. However, as those skilled in the art will understand, the invention may be implemented without following these specific details.
[0031] This invention can be presented in various forms, some of which will be described below. However, before that, terms and optical concepts related to this disclosure will be introduced.
[0032] In this article, the side of the lens closest to the observed tissue is called the first surface, and the other side of the lens opposite the first surface is called the second surface. When indicating that the first or second surface of the lens is convex, it means that most of the area of the first or second surface of the lens near the center is convex. When indicating that the first or second surface of the lens is concave, it means that most of the area of the first or second surface of the lens near the center is concave.
[0033] Figure 1The diagram illustrates the first principle of the folding-back cellular microendoscopic imaging system of the present invention. This first embodiment of the cellular microendoscopic imaging system includes: a protective cover plate 110, an image sensor 120, a lens assembly 130, and a reflector 140. The protective cover plate 110 and the image sensor 120 are located on the same side of the lens assembly 130. Light from the surface of the observed tissue can pass through the protective cover plate 110 into the lens assembly 130. The reflector 140 is located on the other side of the lens assembly 130. The lens assembly 130 and the reflector 140 are coaxial. The protective cover plate 110 is located to the left of the axis of the reflector 140 (note: left and right are actually relative in practical applications). The image sensor 120 is located to the right of the axis of the reflector 140. That is, the image sensor 120 and the protective cover plate 110 are symmetrically arranged on both sides of the axis of the reflector 140 to achieve off-axis imaging. The endoscopic imaging system in this first principle schematic diagram adopts an off-axis design to reduce aberrations caused by on-axis and off-axis imaging. Specifically, the distance between the central axis of the protective cover 110 and the axis of the reflector 140 is d1, and the distance between the central axis of the image sensor 120 and the axis of the reflector 140 is d2. d1 and d2 are equal and 0.5mm≤d1=d2≤2.5mm. Furthermore, in this design, the dimensions of the image sensor 120 (image space imaging area) and the protective cover 110 (object space observed area) are approximately 1:1. In the small imaging space, light passes through the same lens assembly 130 twice from different directions. The optical symmetry structure is fully utilized to correct aberrations such as coma, distortion, and transverse chromatic aberration, so that the aberrations generated during the two passes through the same lens assembly 130 cancel each other out, thereby achieving super-resolution imaging. This cell microendoscopic imaging system reflects light through a mirror 140, causing the light to be reflected back and imaged, thereby effectively reducing the total length D of the optical imaging system, making it applicable to more small spaces. Specifically, the total length D of the optical imaging system is, for example, not less than 4 mm and not more than 7 mm.
[0034] Figure 2This diagram illustrates a second principle of the catadioptric cellular microendoscopic imaging system according to an embodiment of the present invention. In this second embodiment, to allow the protective cover 110 to be closer to the target to be observed, the distance between the protective cover 110 and the lens assembly 130 is slightly greater than the distance between the image sensor 120 and the lens assembly 130. The distance h between the protective cover 110 and the image sensor 120 along the axial direction of the lens assembly 130 is, for example, 200 micrometers to 500 micrometers. The planes containing the protective cover 110 and the image sensor 120 are both perpendicular to the axis of the lens assembly 130. The distance d1 between the center of the protective cover 110 and the axis of the lens assembly 130 is the distance d2 between the center of the image sensor 120 and the axis of the lens assembly 130. Since the protective cover 110 and the image sensor 120 are almost on the same plane, d1 and d2 are equal. The image sensor 120 is, for example, a CMOS or CCD, and the reflector 140 is, for example, a spherical or aspherical concave reflector. By adjusting the reflector 140 and the lens assembly 130, the following can be achieved: Figure 2 The off-axis imaging shown is capable of meeting the super-resolution requirements for cell biopsy, with an imaging resolution of, for example, 0.7 micrometers to 3 micrometers.
[0035] Figure 3 The first embodiment of the present invention shows a schematic diagram of a catadioptric cellular microendoscopic imaging system. The third embodiment shows a specific configuration of the lens assembly 130, which is composed of, for example, four lenses, including a first lens 131, a second lens 132, a third lens 133, and a fourth lens 134. The first lens 131, the second lens 132, the third lens 133, and the fourth lens 134 are arranged sequentially from the protective cover 110 to the reflector 140, and there is a preset spacing between adjacent lenses. Specifically, the first lens 131 is, for example, a biconvex lens, with a convex first surface and a convex second surface; the second lens 132 is, for example, a convex-concave lens, with a convex first surface and a concave second surface; the third lens 133 is, for example, a concave-convex lens, with a concave first surface and a convex second surface; the fourth lens 134 is, for example, a convex-concave lens, with a convex portion near the center of its first surface and a concave portion away from the center, similar to a W or M shape, and a concave portion near the center of its second surface and a convex portion away from the center. The first side refers to the side of the lens closest to the protective cover 110 (the surface of the tissue being observed), and the second side refers to the other side of the lens opposite to the first side.
[0036] Figure 4This diagram illustrates the assembly structure of a folding-back cellular microendoscopic imaging system according to a first embodiment of the present invention. The system includes a protective cover plate 110, an image sensor 120, a lens assembly 130, and a reflector 140. The protective cover plate 110 is disposed between the lens assembly 130 and the surface of the tissue being observed, protecting the lens assembly 130. The outer surface (lower surface) of the protective cover plate 110 typically coincides with the surface of the tissue being observed, allowing for close contact with the tissue surface for observation. The protective cover plate 110 can be made of materials such as sapphire glass, which has good wear resistance.
[0037] Lens assembly 130 includes a first lens 131, a second lens 132, a third lens 133, a fourth lens 134, and a filter 135. The first lens 131, second lens 132, third lens 133, fourth lens 134, and filter 135 are arranged sequentially along the axis of the reflector 140 from the protective cover 110 to the reflector 140. The optical centers of each lens and the optical center of the reflector 140 are located on the same straight line (i.e., the optical axis). The protective cover 110, image sensor 120, and lens assembly 130 are, for example... Both the lens assembly 130 and the mirror 140 are housed in the first lens barrel 210, and the mirror 140 is housed in the second lens barrel 220. The first lens barrel 210 and the second lens barrel 220 are connected by threads, for example. The distance between the lens assembly 130 and the mirror 140 can be adjusted by rotating the threads. The first lens barrel 210 includes, for example, a trumpet-shaped structure with a gradually increasing inner diameter. From the side of the observed tissue surface to the side of the mirror 140, the apertures of the first lens 131, second lens 132, third lens 133, and fourth lens 134 inside the first lens barrel 210 gradually increase. The second lens barrel 220 is similar to a bottle cap, for example, and contains the mirror 140. The opening of the second lens barrel 220 faces the first lens barrel 210, and the inner wall of the second lens barrel 220 is connected to the outer wall of the first lens barrel 210 by threads. The filter 135 is used, for example, to selectively transmit light of the target wavelength band and block interfering light, reducing the influence of non-target wavelength band light on imaging.
[0038] Of course, in order to obtain better imaging results, each lens in the lens assembly 130 is, for example, an aspherical optical lens. The first lens barrel 210 and the second lens barrel 220 can also be fixedly connected by non-threaded means such as snaps or glue. Furthermore, the first lens barrel 210 can be extended and the reflector 140 can also be set in the first lens barrel 210, all of which are within the scope of protection of this invention.
[0039] Figure 5A schematic diagram of a catadioptric cellular microendoscopic imaging system according to a second embodiment of the present invention is shown. This second embodiment is similar to the first embodiment, except that the lens assembly 130 of the endoscopic imaging system in this second embodiment includes five lenses. The first lens 131 is, for example, a biconvex lens, with both its first and second surfaces being convex. The second lens 132 is, for example, a biconcave lens, with both its first and second surfaces being concave. The third lens 133 is, for example, a concave-convex lens, with its first surface being concave and its second surface having a concave portion near the center and a convex portion away from the center. The fourth lens 134 is, for example, a concave-convex lens, with its first surface being concave and its second surface being convex. The fifth lens 136 is, for example, a biconcave lens, with its first surface being concave and its second surface having a concave portion near the center and a convex portion away from the center. Compared to the first embodiment with four lenses, the lens assembly 130 of this second embodiment has better aberration correction capabilities and can acquire higher resolution images.
[0040] Similarly, Figure 6 This diagram illustrates a catadioptric cellular microendoscopic imaging system according to a third embodiment of the present invention. This third embodiment is similar to the second embodiment, except that the lens assembly 130 of the endoscopic imaging system in this third embodiment includes six lenses. The first lens 131 is, for example, a convex-concave lens, with a convex first surface and a concave second surface; the second lens 132 is, for example, a concave-convex lens, with a concave first surface and a convex second surface; the third lens 133 is, for example, a convex-concave lens, with a convex first surface and a concave second surface; the fourth lens 134 is, for example, a convex-concave lens, with a convex first surface near the center and a concave second surface away from the center, and a concave second surface near the center and a convex second surface away from the center; the fifth lens 136 is, for example, a concave-convex lens, with a concave first surface and a convex second surface; the sixth lens 137 is, for example, a biconcave lens, with a concave first surface, slightly convex near the center and concave away from the center, and a concave second surface near the center and convex away from the center, resembling an M-shape. Compared to the fifth embodiment with five lenses, the lens assembly 130 of the sixth embodiment has a better aberration correction function and can acquire higher resolution images.
[0041] The lenses in the lens assembly 130 of the aforementioned cell microendoscopic imaging system are typically fixed-focal-length lenses, made of optical plastic, glass, or a mixture of both. This patent utilizes optical materials in the corresponding ultraviolet or near-infrared bands, and can also be used for cell microendoscopic imaging in these two bands. The lenses can be manufactured using traditional grinding, aspherical glass molding, injection molding, or wafer-level optics (WLO) processes. Compared to imaging systems relying on built-in precision mechanical focusing, the cost and size of this application's solution are significantly reduced. Furthermore, if the endoscope requires a wide-angle mode, this can be achieved with another wide-angle lens. That is, in addition to the aforementioned endoscope imaging system for achieving the cell microscopic mode (close-up), the entire endoscope can also include a wide-angle lens to achieve the wide-angle mode. Specifically, when a normal wide-angle endoscopic observation is required, the physician can perform the examination as if using a normal endoscope (this mode is a wide-angle mode, in which the top of the endoscope and the observed surface tissue are kept at a certain distance); however, when a suspicious condition is observed in a certain area, the entire endoscope can be moved to the tissue in the suspicious area, and the endoscope cover 110 and the surface of the observed tissue should be kept at zero distance and prevented from sliding left and right, thereby switching to the above-mentioned endoscopic imaging system for close-range cell observation, realizing "optical biopsy" of cells.
[0042] The refracting cellular microendoscopic imaging system and cellular microendoscopic endoscope provided by this invention refract light through a reflector and correct aberrations in off-axis imaging using a symmetrical lens assembly, completely eliminating the need for the micro-mechanical focusing mechanism required in traditional cellular endoscopes. In this cellular microendoscopic imaging system, light obtained from the surface of the observed tissue through the protective cover slip travels twice through the same lens assembly, automatically canceling coma, distortion, and transverse chromatic aberration using a nearly symmetrical optical path, thereby achieving super-resolution imaging. It meets the resolution requirements of close-range "optical biopsy" without moving any lens in the lens assembly, fundamentally eliminating frequent focusing operations and the risk of defocusing due to metal fatigue, return gaps, etc., resulting in higher reliability and stability.
[0043] Furthermore, the cell microscopic endoscope provided by the present invention includes a folding-back endoscope imaging system as described above that can perform cell microscopic observation. By closely attaching the protective cover at the distal end of the endoscope to the target area, the surface of the tissue being observed is in close contact with the outer surface of the protective cover, thereby performing cell microscopic observation to meet the needs of cell-level "optical biopsy".
[0044] By employing this refractory cellular microendoscopic imaging system, the distal end of the endoscope no longer needs to house the motor, shape memory alloy, or other driving components required for focusing. This reduces the diameter of the endoscope, allowing it to directly enter and observe smaller cavities. The cellular microendoscopic imaging system of this invention is inexpensive, economical for single-use applications, and completely avoids the cross-contamination problems that can result from repeated use.
[0045] The above description does not provide detailed explanations of the technical aspects of the device's layout and injection molding. However, those skilled in the art should understand that various technical means can be used to form the desired shape and thickness. Furthermore, to form the same structure, those skilled in the art can design methods that are not entirely identical to those described above. Additionally, although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination.
[0046] The embodiments of the present invention have been described above. However, these embodiments are merely illustrative and not intended to limit the scope of the invention. The scope of the invention is defined by the appended claims and their equivalents. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of the invention, and all such substitutions and modifications should fall within the scope of the invention.
Claims
1. A refractory cellular microendoscopic imaging system, characterized in that, include: A lens assembly having at least two lenses; A protective cover is located between the lens assembly and the surface of the tissue being observed, through which light from the surface of the tissue being observed enters the lens assembly; An image sensor for converting light signals into electrical signals, wherein the image sensor and the protective cover are located on the same side of the lens assembly; A reflector, located on the other side of the lens assembly, is coaxial with the lens assembly and reflects light passing through the protective cover to the image sensor. The protective cover and the image sensor are arranged symmetrically with respect to the axis of the lens assembly. Light from the surface of the observed tissue is reflected by the mirror after passing through the protective cover and the lens assembly, and then passes through the lens assembly again to finally form an image on the image sensor.
2. The endoscopic imaging system according to claim 1, characterized in that, At least one lens in the lens assembly is an aspherical lens.
3. The endoscopic imaging system according to claim 1, characterized in that, The lens assembly also includes a filter located on the side of the lens assembly closest to the reflector.
4. The endoscopic imaging system according to claim 1, characterized in that, The lens assembly is disposed in the first lens barrel, and the reflector is disposed in the second lens barrel. The first lens barrel and the second lens barrel are connected by threads to adjust the distance between the lens assembly and the reflector.
5. The endoscopic imaging system according to claim 4, characterized in that, The first endoscope tube is a trumpet-shaped structure with an inner diameter that gradually increases along the optical axis, and the diameter of each lens in the lens assembly gradually increases along the optical axis from the surface of the observed tissue to the reflecting mirror.
6. The endoscopic imaging system according to claim 1, characterized in that, The reflector includes an aspherical concave reflector.
7. The endoscopic imaging system according to claim 1, characterized in that, The image sensor can be either CMOS or CCD.
8. The endoscopic imaging system according to claim 1, characterized in that, The lens assembly includes a first lens, a second lens, a third lens, and a fourth lens, which are arranged sequentially along the axis of the reflector from the protective cover to the reflector. The first lens is a biconvex lens, with a first surface being convex and a second surface opposite to the first surface also being convex. The second lens is a convex-concave lens, with the first surface of the second lens being convex and the second surface opposite to the first surface being concave. The third lens is a concave-convex lens, with the first surface of the third lens being concave and the second surface opposite to the first surface being convex. The fourth lens is a convex-concave lens, with the first surface of the fourth lens being convex and the second surface opposite to the first surface being concave.
9. The endoscopic imaging system according to claim 1, characterized in that, The lens assembly includes a first lens, a second lens, a third lens, a fourth lens, and a fifth lens, which are arranged sequentially along the axis of the reflector from the protective cover to the reflector. The first lens is a biconvex lens, with a first surface being convex and a second surface opposite to the first surface being convex. The second lens is a biconcave lens, wherein the first surface of the second lens is concave and the second surface opposite to the first surface is concave. The third lens is a concave-convex lens, with the first surface of the third lens being concave and the second surface opposite to the first surface being convex. The fourth lens is a concave-convex lens, with the first surface of the fourth lens being concave and the second surface opposite to the first surface being convex. The fifth lens is a biconcave lens, with its first surface being concave and its second surface, which is opposite to the first surface, also being concave.
10. The endoscopic imaging system according to claim 1, characterized in that, The lens assembly includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens, which are arranged sequentially along the axis of the reflector from the protective cover to the reflector. The first lens is a convex-concave lens, with the first surface of the first lens being convex and the second surface opposite to the first surface being concave. The second lens is a concave-convex lens, with the first surface of the second lens being concave and the second surface opposite to the first surface being convex. The third lens is a convex-concave lens, with the first surface of the third lens being a convex surface and the second surface opposite to the first surface being a concave surface; The fourth lens is a convex-concave lens, with the first surface of the fourth lens being a convex surface and the second surface opposite to the first surface being a concave surface; The fifth lens is a concave-convex lens, with the first surface of the fifth lens being concave and the second surface of the image lens being convex, opposite to the first surface. The sixth lens is a biconcave lens, with its first surface being concave and its second surface, which is opposite to the first surface, also being concave.
11. A cell microendoscopy, characterized in that, include: The close-range lens formed by the refractory cell microendoscopic imaging system according to any one of claims 1 to 10, wherein the close-range lens is disposed at the distal end of the cell microendoscopic body.
12. The cell microendoscopy according to claim 11, characterized in that, The cell microendoscopy is a single-use instrument or a reusable cell microendoscopy.