Fluorescent confocal microscopic endoscopic imaging lens

Abstract

The invention discloses a fluorescent confocal microscopic endoscopic imaging lens, which comprises three groups of doublet lenses, specifically comprising a first lens group, a second lens group and a third lens group, the first lens group comprises a plano-concave lens and a first biconvex lens which are sequentially arranged from an object space side to an image space side, and the second lens group comprises a plano-concave lens and a second biconvex lens which are sequentially arranged from an object space side to an image space side; the detector is used for collecting fluorescence signals emitted by an object space and adjusting light angles; the second lens group comprises a first negative meniscus lens and a second biconvex lens, and is used for relaying transmission light and balancing aberration so as to gently transition a light angle; and the third lens group comprises a second negative meniscus lens and a positive meniscus lens and is used for focusing the light to the end face of the optical fiber bundle. The lens is compact in structure, reasonable in light path matching and suitable for human tissue close imaging scenes, has the advantages of being high in resolution, low in distortion, excellent in chromatic aberration control and the like, and is suitable for digestive tract early cancer diagnosis and confocal imaging system integration.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of endoscopic imaging devices, and more particularly, to a fluorescence confocal microscopic endoscopic imaging lens. BACKGROUND

[0002] The fluorescence confocal microscopic endoscope is an imaging device that can observe the cells of the diseased tissue in real time in the body, and is usually composed of a fiber imaging probe and a confocal imaging main body. The fiber imaging probe is composed of a fiber bundle and an imaging lens at the distal end thereof, and together determines the resolution of the system. The fiber imaging probe enters the body through the instrument channel of a conventional white light endoscope, and can be used to examine the mucosal lesions of the digestive system, and to observe the pathological characteristics of diseases such as adenocarcinoma, inflammation, biliary stricture, and pancreatic cysts during surgery.

[0003] However, the confocal microscopic endoscopic imaging lenses currently developed in the industry cannot perform high-performance imaging at any position in the digestive tract with the same lens. Specifically, the lenses used for the gastrointestinal tract are generally large in diameter, and usually use high-cost aspheric lenses to achieve cell-level resolution. However, the size of the lenses cannot be used for the biliary tract, and the fine-diameter lenses used for the biliary tract cannot achieve the required resolution for observing cells. SUMMARY

[0004] The purpose of the present application is to provide a fluorescence confocal microscopic endoscopic imaging lens that can perform high-performance imaging at any position in the digestive tract with an ultra-fine diameter and low cost, and can observe the characteristics of the cells of the diseased tissue at any position in the digestive tract.

[0005] The present application provides a fluorescence confocal microscopic endoscopic imaging lens in the first aspect, comprising:

[0006] Three sets of double-cemented lenses, specifically including a first lens group, a second lens group, and a third lens group, wherein,

[0007] The first lens group includes a plano-concave lens and a first double-convex lens arranged in order from the object side to the image side, for collecting the fluorescence signal emitted from the object side and adjusting the angle of light;

[0008] The second lens group includes a first negative meniscus lens and a second double-convex lens, for relaying the transmission of light and balancing aberrations to smoothly transition the angle of light;

[0009] The third lens group includes a second negative meniscus lens and a positive meniscus lens, for focusing the light to the end face of the fiber bundle.

[0010] In this scheme, the three sets of double-cemented lenses are arranged in order along the optical axis direction of the first lens group, the second lens group, and the third lens group.

[0011] In this scheme, the three sets of double-cemented lenses are directly optically cemented without air spacing or mechanical spacing.

[0012] In the scheme, the outer diameters of the three groups of double-cemented lenses are the same, and the outer diameter ranges from 0.5mm to 1mm.

[0013] In the scheme, the distance between the first mirror group and the object ranges from 0um to 300um, and the distance from the object to the image ranges from 3mm to 10mm.

[0014] In the scheme, the numerical aperture NAobj of the first mirror group ranges from 0.5 to 0.8.

[0015] In the scheme, the numerical aperture NAimg of the third mirror group ranges from 0.25 to 0.4, and the ratio of the numerical aperture NAobj of the first mirror group to the numerical aperture NAimg of the third mirror group is 2.

[0016] In the scheme, the working waveband of the three groups of double-cemented lenses ranges from 400nm to 900nm, covering the visible light to near-infrared region.

[0017] In the scheme, the front surface of the first mirror group is a plane structure.

[0018] In the scheme, the three groups of double-cemented lenses work in water as the medium, which is used to simulate the refractive index environment of biological tissues.

[0019] The application discloses a fluorescent confocal microscopic endoscopy imaging lens, which has the characteristics of superfine diameter and high performance, and has the effects of simple structure, low cost and easy packaging, and can be applied to imaging of mucous membrane layers in various parts of digestive tracts and observing cell structures to judge the occurrence of diseases such as cancers. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 A flow chart of the fluorescent confocal microscopic endoscopy imaging lens is shown.

[0021] Figure 2 A spot diagram of the fluorescent confocal microscopic endoscopy imaging lens under a focusing condition is shown.

[0022] Figure 3 An MTF curve diagram of the fluorescent confocal microscopic endoscopy imaging lens is shown.

[0023] Figure 4 A ray tracing sector diagram of the fluorescent confocal microscopic endoscopy imaging lens is shown.

[0024] Figure 5 A field curvature and distortion diagram of the fluorescent confocal microscopic endoscopy imaging lens is shown.

[0025] Figure 6 A chromatic aberration focal shift diagram of the fluorescent confocal microscopic endoscopy imaging lens is shown.

[0026] Element No.

[0027] DETAILED DESCRIPTION

[0028] In order to more clearly understand the above-mentioned purposes, features and advantages of the present application, the present application will be further described in detail below in conjunction with the drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0029] In the following description, a large number of specific details are set forth in order to facilitate a thorough understanding of the present application, however, the present application can also be implemented in other ways different from those described herein, and therefore, the scope of protection of the present application is not limited by the specific embodiments disclosed below.

[0030] Figure 1 A two-dimensional structural schematic diagram of a fluorescence confocal microscopic endoscopy imaging lens is shown.

[0031] As Figure 1 shown, the present application discloses a fluorescence confocal microscopic endoscopy imaging lens, comprising:

[0032] three groups of double-cemented lenses, specifically including a first lens group 1, a second lens group 2 and a third lens group 3, wherein,

[0033] The first lens group 1 includes a plano-concave lens 11 and a first biconvex lens 12 arranged in order from the object side to the image side, for collecting the fluorescence signal emitted from the object side and adjusting the light angle;

[0034] The second lens group 2 includes a first negative meniscus lens 21 and a second biconvex lens 22, for relaying transmission of light and balancing aberration to gently transition the light angle;

[0035] The third lens group 3 includes a second negative meniscus lens 31 and a positive meniscus lens 32, for focusing the light to the end face of the fiber bundle.

[0036] It should be noted that in the present embodiment, the specific description of the fluorescence confocal microscopic endoscopy imaging lens satisfies the image side telecentric focusing, and can realize uniform imaging of the image plane, specifically, as Figure 1 shown, the three groups of double-cemented lenses are arranged in order along the optical axis direction of the first lens group 1, the second lens group 2 and the third lens group 3, wherein the three groups of double-cemented lenses work with water as the medium, for simulating the refractive index environment of biological tissues, as Figure 1As shown, the first mirror group 1 includes a plano-concave lens 11 and a first biconvex lens 12 arranged in sequence from the object side to the image side, wherein the plano-concave lens 11 is close to the object side, used for collecting the fluorescent signal emitted from the object side and adjusting the light angle, specifically for divergence adjustment, wherein the equivalent focal power of the glued plano-concave lens 11 is positive, taking into account the working distance and angle expansion, specifically, the plano-concave lens 11 collects the fluorescent signal at a certain distance from the object side, and the incident light is divergent, and the focal power is negative, while the first biconvex lens 12 is used to balance the chromatic aberration, and the focal power is positive, the plano-concave lens 11 and the first biconvex lens 12 are arranged and glued in sequence from the object side to form a double-glued lens, which is equivalent to a plano-convex lens.

[0037] Further, the second mirror group 2 is a relay lens group, specifically including a first negative meniscus lens 21 and a second biconvex lens 22, arranged close to the first mirror group 1, used for relaying the light and balancing the aberration to smoothly transition the light angle, specifically, the first negative meniscus lens has one convex and one concave surface, showing negative focal power, while the second biconvex lens has two convex surfaces, showing positive focal power, wherein the main purpose is to make the main light angle transition smooth, continue the light path and suppress chromatic aberration and spherical aberration and other aberration factors, due to the absence of air gap in this group, it has the advantages of high compactness and easy batch assembly, which can greatly simplify lens assembly, without the need to set a gasket to separate the lenses, which can improve the lens assembly yield.

[0038] The third mirror group 3 is a focusing lens group, specifically including a second negative meniscus lens 31 and a positive meniscus lens 32, as shown Figure 1 arranged close to the image plane, specifically used for focusing light onto the end face of the fiber bundle, the second negative meniscus lens has one convex and one concave surface, with a central thickness smaller than an edge thickness, showing negative focal power, while the positive meniscus lens has one convex and one concave surface, with a central thickness greater than an edge thickness, showing positive focal power, wherein the image plane corresponds to the end face of the fiber bundle, the third mirror group 3 accurately focuses the object side main light after correction onto the end face of the fiber bundle, so that the focal spot diameter matches the fiber core diameter, and the exit angle matches the circular spot of the fiber numerical aperture, effectively ensuring the light coupling efficiency, wherein, as shown Figure 2 The point spread function of the fluorescent confocal microscopic endoscopic imaging lens of the present application under focusing condition can be observed, and the focal spot morphology is symmetrical, the energy is concentrated, and there is no obvious coma or distortion widening phenomenon.

[0039] Further, the three groups of double-glued lenses are directly optically glued without air gap or mechanical gap, the materials are all optical glass, and the surfaces are spherical or planar, which is convenient for precise alignment and microstructure packaging, and the outer diameters of the three groups of double-glued lenses are the same, and the outer diameter is In actual application, the outer diameter The range of the distance between the first lens group 1 and the object is "0.5mm-1mm".

[0040] Further, in an embodiment of the application, the distance between the first lens group 1 and the object ranges from "0μm-300μm", and the distance from the object to the image ranges from "3mm-10mm".

[0041] Further, in an embodiment of the application, the numerical aperture NAobj of the first lens group 1 ranges from "0.5-0.8", and the numerical aperture NAimg of the third lens group 3 ranges from "0.25-0.4", wherein the ratio of the numerical aperture NAobj of the first lens group 1 to the numerical aperture NAimg of the third lens group 3 is "2".

[0042] Further, in an embodiment of the application, the working wavelength range of the three groups of double-cemented lenses is "400nm-900nm", covering the visible light to the near-infrared region.

[0043] It should be noted that, in this embodiment, the numerical aperture NAobj of the first lens group 1 satisfies "0.5≤NAobj≤0.8", and the numerical aperture NAimg of the third lens group 3 satisfies "0.25≤NAimg≤0.4", wherein the numerical aperture NAobj of the first lens group 1 and the numerical aperture NAimg of the third lens group 3 satisfy the following constraint relationship: "NAobj / NAimg=2", wherein the lens can realize cell-level resolution imaging under the constraint of NAobj / NAimg=2.

[0044] Further, the distance d between the first lens group 1 and the object side (object side) satisfies "0≤d≤300μm", which is used to form the working distance, and the distance L from the object side to the image side (fiber bundle end surface) satisfies "3mm≤L≤10mm", and in application, the working wavelength w of the lens satisfies "400nm≤w≤900nm".

[0045] Further, in an embodiment of the application, the front surface of the first lens group 1 is a plane structure.

[0046] It should be noted that, in this embodiment, the front surface corresponds to the surface of the plano-concave lens 11 in the first lens group 1 close to the object side, wherein since the plano-concave lens 11 is close to the object side, and the front surface corresponds to the optical plane structure, in application, physical friction on the tissue can be reduced, and the tissue can be prevented from being scratched, and the lens can be more conveniently cleaned and wiped.

[0047] Furthermore, in one embodiment of the invention, a set of parameters is configured for application. Specifically, the numerical aperture NAobj of the first lens group is "0.5", the numerical aperture NAimg of the third lens group is "0.25", the working distance is "d = 250 μm", the total lens length (corresponding to the distance from the object plane to the image plane) is "L = 3.74 mm", and the lens diameter (outer diameter of the three cemented doublet lenses) is... The operating wavelength w is "785nm to 860nm".

[0048] This invention discloses a fluorescence confocal microscopic endoscopic imaging lens, characterized by its ultra-narrow diameter, high performance, and simple structure, low cost, and easy packaging. It can be simultaneously applied to imaging the mucosal layers of various parts of the digestive tract, observing cellular structures to determine the occurrence of diseases such as cancer. The lens structure is highly integrated, and the optical path design follows the principle of NA (Numerical Aperture) ratio optimization, achieving cell-level resolution within an extremely short structural length. For example... Figure 3 As shown, the MTF (Modulation Transfer Function) curve of the fluorescence confocal microscopic endoscopic imaging lens of this invention maintains good contrast even at a spatial frequency as high as 134 l p / mm, demonstrating the system's high resolution capability in microscopic structure imaging. Furthermore, it also possesses good chromatic aberration correction and fiber coupling efficiency, such as... Figure 4 The image shown is a fan-shaped plot of the ray tracing of the fluorescence confocal microscopic endoscopic imaging lens of the present invention. Figure 4 This indicates stable control of the principal ray angle, with the rays in the system's center and peripheral fields of view tending to converge, which is beneficial for maintaining focus consistency. Furthermore, the overall lens structure is compact, facilitating practical deployment on endoscopic imaging platforms within 1mm, and is compatible with the signal-to-noise ratio and optical throughput requirements of confocal imaging. Figure 5 and Figure 6 As shown, where, Figure 5 The image shown is a field curvature and distortion diagram of the fluorescence confocal microscopic endoscopic imaging lens of this invention. The distortion is less than 1% within a field of view of ±0.3 mm, demonstrating good geometric imaging stability. Figure 6 The image shown is a chromatic aberration focus shift diagram of the fluorescence confocal microscopic endoscopic imaging lens of the present invention. The focus shift amplitude is controlled at around "2μm" within the target wavelength range, indicating excellent chromatic aberration control.

[0049] In several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other manners. The described device embodiments are merely illustrative. For example, the division of the units is only a logical function division. There can be another division manner for the actual implementation, for example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the displayed or discussed coupling, or direct coupling or communication connection between the components can be indirect coupling or communication connection through some interfaces, devices, or units, and can be electrical, mechanical, or in other forms.

[0050] The units described as separate components can or can not be physically separate, and the components shown as units can or can not be physical units; they can be located in one place, or distributed on multiple network units; and some or all of the units can be selected according to actual needs to achieve the purposes of the embodiments.

[0051] In addition, each functional unit in each embodiment of the present application can be integrated into one processing unit, or each unit can be a separate unit, or two or more units can be integrated into one unit; the integrated unit can be implemented in the form of hardware, or in the form of hardware plus software functional units.

Claims

1. A fluorescence confocal microscopic endoscopic imaging lens, characterized in that, include: The system consists of three groups of cemented doublet lenses, specifically a first lens group, a second lens group, and a third lens group. The first lens group includes a plano-concave lens and a first biconvex lens arranged sequentially from the object side to the image side, used to collect the fluorescence signal emitted from the object side and adjust the angle of the light. The second lens group includes a first negative meniscus lens and a second biconvex lens, which are used to relay light and balance aberrations to smoothly transition the light angle; The third lens group includes a second negative meniscus lens and a positive meniscus lens, used to focus light onto the end face of the fiber bundle.

2. The fluorescence confocal microscopic endoscopic imaging lens according to claim 1, characterized in that, Three sets of cemented doublet lenses are arranged sequentially along the optical axis: the first lens group, the second lens group, and the third lens group.

3. The fluorescence confocal microscopic endoscopic imaging lens according to claim 1, characterized in that, The three sets of cemented doublet lenses are directly optically cemented together, without any air gaps or mechanical gaps.

4. The fluorescence confocal microscopic endoscopic imaging lens according to claim 1, characterized in that, The three sets of cemented doublet lenses have the same outer diameter, ranging from 0.5mm to 1mm.

5. A fluorescence confocal microscopic endoscopic imaging lens according to claim 1, characterized in that, The distance between the first lens group and the object plane ranges from 0 μm to 300 μm, and the distance between the object plane and the image plane ranges from 3 mm to 10 mm.

6. The fluorescence confocal microscopic endoscopic imaging lens according to claim 1, characterized in that, The numerical aperture NAobj of the first mirror group ranges from 0.5 to 0.

8.

7. A fluorescence confocal microscopic endoscopic imaging lens according to claim 6, characterized in that, The numerical aperture NAimg of the third mirror group ranges from 0.25 to 0.4, wherein the ratio of the numerical aperture NAobj of the first mirror group to the numerical aperture NAimg of the third mirror group is 2.

8. The fluorescence confocal microscopic endoscopic imaging lens according to claim 1, characterized in that, The three sets of cemented doublet lenses operate in the wavelength range of 400nm to 900nm, covering the visible light to near-infrared region I.

9. A fluorescence confocal microscopic endoscopic imaging lens according to claim 1, characterized in that, The front surface of the first mirror assembly has a planar structure.

10. A fluorescence confocal microscopic endoscopic imaging lens according to claim 1, characterized in that, The three sets of cemented doublet lenses use water as a medium during operation to simulate the refractive index environment of biological tissues.

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