Optical system of bimodal endoscope, bimodal endoscope imaging probe and endoscope

Abstract

The invention relates to the field of medical instruments, and discloses an optical system of a bimodal endoscope, an endoscope imaging probe and an endoscope, the optical system comprises an objective lens group, an eyepiece group and a light controller which are sequentially arranged in the direction of a main optical axis, and the light controller is used for controlling the propagation direction of white light and near-infrared light. The propagation direction of the white light is kept unchanged after the white light passes through the light controller, the propagation direction of the near-infrared light is changed after the near-infrared light passes through the light controller, the near-infrared light passing through the light controller enters the light conversion module, and the light conversion module comprises an MEMS micromirror and a collimating lens, near-infrared light sequentially passes through the light controller and the MEMS micromirror, and then the propagation direction of the near-infrared light is parallel to the main optical axis, OCT imaging and white light imaging share one set of optical system, the diameter of an insertion part of an existing white light endoscope does not need to be changed, and the OCT imaging can achieve the advantages of being large in view field and large in working distance.

Description

Technical Field

[0001] The invention relates to medical equipment, and in particular to an optical system of a dual-modality endoscope, a dual-modality endoscope imaging probe and an endoscope. Background Art

[0002] Currently, medical white light endoscopes, such as rigid tube endoscopes, electronic endoscopes, 4K endoscopes, etc., have been widely used in clinical practice, helping doctors provide high-definition images in minimally invasive surgeries.

[0003] In early cancer screening, doctors currently use a white light endoscope to observe the lesion, determine the location, and then take a biopsy sample to confirm whether it is a diseased cell based on pathological theory. There are currently two problems that need to be solved with this method. One is that the entire process takes about 5 working days, which is time-consuming. The other is that biopsy sampling depends on the doctor's clinical experience, which has the risk of missed detection.

[0004] OCT imaging technology is known as optical biopsy, which can achieve deep imaging of about 5mm below the surface. Currently, OCT has been widely used in the field of ophthalmology.

[0005] At present, there are related patents on combining OCT with white light endoscopes, such as CN115444361A, which discloses a composite imaging system, including an image processing unit, an imaging unit, an endoscopic catheter, a fiber endoscope and an OCT imaging catheter arranged in the endoscopic catheter and respectively connected to the imaging system, and a rotation drive component, wherein the fiber endoscope and the OCT imaging catheter each exist in parallel in an independent form, that is, the imaging system disclosed in the patent application adopts a dual-channel form, one channel for the white light endoscope and one channel for the OCT. Although this method combines the white light endoscope and the OCT, because the two adopt a dual-channel form, the overall insertion part of the endoscope is relatively large; secondly, due to the OCT scanning method, the imaging field of view is very small, or only specific scanning methods such as circular scanning can be realized, which is not applicable to the current common surgical plans. Summary of the invention

[0006] The purpose of the present invention is to overcome the problems in the prior art that the insertion part of the endoscope is too large and the OCT imaging field of view is small, and to provide an optical system of a dual-modality endoscope, a dual-modality endoscope imaging probe and an endoscope, wherein the white light imaging structure and the OCT imaging structure in the optical system can share a set of optical paths, there is no need to change the diameter of the existing endoscope insertion part, and the OCT imaging field of view is significantly increased.

[0007] In order to achieve the above-mentioned object, the first aspect of the present invention provides an optical system of a dual-modal endoscope, wherein the optical system comprises: an objective lens group, an eyepiece lens group and a light controller arranged in sequence along the main optical axis direction, wherein the light controller is used to control the propagation direction of white light and near-infrared light, the propagation direction of white light remains unchanged after passing through the light controller, the propagation direction of near-infrared light is changed after passing through the light controller, and the near-infrared light after passing through the light controller enters the light conversion module;

[0008] The light conversion module comprises: a MEMS micromirror and a collimating lens, wherein the propagation direction of the near-infrared light is parallel to the main optical axis after passing through the light controller and the MEMS micromirror in sequence.

[0009] The imaging structure of a traditional white light endoscope generally includes an objective lens group and an eyepiece group. Near-infrared light, such as near-infrared laser, is generally used for OCT imaging. After being transmitted through a single-mode optical fiber, it is converted into parallel light through a collimating lens. After being reflected by a MEMS micromirror, it is reflected by a light controller and then reaches the object side through an eyepiece group and an objective lens group. The reflected / scattered light beam from the object side is collected by the objective lens again and forms a parallel light beam after passing through the eyepiece group. This parallel light beam is focused by a collimating lens after passing through the light controller and MEMS micromirror, and further in the next component (such as a single-mode optical fiber). The optical fiber core of the reference arm generates interference with the returning photosynthetic beam of the reference arm, and is finally received by the detector for analysis and imaging. Therefore, OCT imaging can share the same optical path with traditional white light imaging. In the OCT optical path, the light beam scanned by the MEMS forms a real image plane after passing through the eyepiece group, which coincides with the real image plane at the front end of the eyepiece group of the white light endoscope. According to the reversible principle of the optical path, the OCT optical path can also reuse the objective lens group of the white light endoscope, thereby greatly improving the imaging range. Compared with traditional OCT, its imaging range has been improved by orders of magnitude.

[0010] The present invention adds a light controller and a light conversion module to the imaging structure of a traditional white light endoscope, wherein the light controller is used to separate white light and near-infrared light so that they propagate in different directions, wherein the white light continues to propagate in the original direction and can further enter other units for analysis and processing, while the near-infrared light is changed in direction and further converted by the light conversion module.

[0011] The present invention has no special requirements for the specific structure of the eyepiece group and the objective lens group, and the eyepiece group and objective lens group used in existing white light endoscopes can be used. Generally speaking, the objective lens group includes a first glued lens group and a second glued lens group, wherein the first glued lens group is used to collect light under a large field of view, and the second glued lens group is used to eliminate aberrations.

[0012] The first glued lens group includes a negative lens and a plurality of prisms glued to the negative lens, wherein the negative lens is close to the object side, and the prisms are selected from different prisms according to different viewing angles, such as 30°, 70°, etc. The first glued lens group may further include other lenses (such as convex lenses or concave lenses), and the other lenses can be glued to the prisms;

[0013] The second glued lens group generally also uses glued lenses, which can be double glued lenses or triple glued lenses. The glued lenses can be convex lenses and / or concave lenses, which can be selected according to needs.

[0014] The eyepiece group is a double-cemented lens group, which can be a cemented convex lens and / or concave lens.

[0015] Preferably, the light conversion module further includes a near infrared filter, which is located between the MEMS micromirror and the collimating lens and is used to allow near infrared light to pass through. After the near infrared filter is provided, stray light interference can be further reduced and detection accuracy can be improved.

[0016] Preferably, the optical system further comprises a white light filter, which is located on the image side of the light controller along the main optical axis and is used to allow white light to pass through. After the white light filter is provided, stray light interference can be further reduced and detection accuracy can be improved.

[0017] Preferably, the optical controller is a spectroscope or an optical switch. The present invention has no special requirements for the spectroscope, for example, it can be a 5:5 spectroscope, or a 3:7 spectroscope, etc. Existing optical switches can be applicable, for example, it can be a MEMS optical shutter produced by RECISELEY MICROTECHNOLOGY CORP, and controlled by OSX-150. When an optical switch is used, the detectors in the COMS and OCT systems work at different times through time division, and the interval can be ms.

[0018] Preferably, the light controller is a dichroic mirror, and the angle between the dichroic mirror and the main optical axis is α, 0°<α<90°. The dichroic mirror of the present invention is arranged behind the eyepiece group, and the light transmitted by the eyepiece group is parallel light, so there is no strict requirement for the installation position of the dichroic mirror, so it is easy to manufacture and realize.

[0019] Preferably, α is 45°. The specific value of α can be any value as long as it meets the requirements, such as 30°, 45°, 60°, 80°, etc., preferably 45°.

[0020] Preferably, the optical system further comprises n groups of steering mirror groups, n is an odd number, the n groups of steering mirror groups are located between the objective lens group and the eyepiece lens group, and the imaging point of the last group of the steering mirror groups coincides with the focus of the eyepiece lens group. The function of the steering mirror group is to enable the object image from the objective lens group or the previous steering mirror group to be imaged 1:1, and the object image passing through the steering mirror group is flipped 180°, so in order to keep the object image entering the eyepiece group as an upright image, an odd number of steering mirror groups is generally selected, such as n can be 1, 3, 5, 7, etc.

[0021] Preferably, each steering mirror group comprises two steering lenses arranged in parallel, and the optical axis of the steering lens is parallel to the main optical axis. Each steering lens can be a single convex lens or a single concave lens, or a cemented lens, such as a concave and / or convex lens cemented together.

[0022] A second aspect of the present invention provides a dual-modality endoscopic imaging probe, which includes the optical system described in the first aspect of the present invention.

[0023] Preferably, the probe further includes a first shell and a second shell connected to the first shell, wherein the objective lens group and the eyepiece group are arranged in the second shell, the dichroic mirror, the MEMS micromirror and the collimating lens are arranged in the first shell, the first shell is also connected to an optical fiber, and the focus of the collimating lens is the light emission / incident point of the optical fiber.

[0024] With this structure, the light emitted from the optical fiber is collimated into parallel light by the collimating lens, and then enters the eyepiece group and the objective lens group in turn after being reflected by the MEMS micromirror and the dichroic mirror. The light reflected by the object returns along the aforementioned path, is focused by the collimating lens, enters the optical fiber, and further enters other components.

[0025] Preferably, n groups of steering mirror groups are further arranged in the second shell, n is an odd number, the n groups of steering mirror groups are located between the objective lens group and the eyepiece group, and the imaging point of the last group of the steering mirror groups coincides with the focus of the eyepiece group.

[0026] Preferably, the first housing is connected with an optical bayonet, and the optical bayonet is used to connect with an adapter.

[0027] A third aspect of the present invention provides an endoscope, which includes the probe described in the second aspect of the present invention.

[0028] The present invention adds components such as a light controller (such as a dichroic mirror, a beam splitter, an optical switch, etc.), a MEMS micromirror, and a collimating lens to a traditional white light imaging structure, so that OCT imaging can share a set of optical systems with white light imaging, without changing the diameter of the existing white light endoscope insertion part. In addition, OCT imaging can also make use of the optical characteristics of the large field of view and large working distance of the white light imaging objective lens group and the magnification function of the white light imaging eyepiece group, so that OCT imaging can achieve the advantages of a large field of view and a large working distance. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the structure of the optical system of the dual-modality endoscope;

[0030] Figure 2 It is a schematic diagram of the propagation path of light in the optical system of a dual-modality endoscope.

[0031] Description of Reference Numerals

[0032] 1. Objective lens group; 1a. First cemented lens group; 1b. Second cemented lens group; 2. Steering lens group; 2a. Steering lens; 3. Eyepiece group; 4. Light controller; 5. MEMS micromirror; 6. Collimating lens; 7. Second shell; 8-First shell; 9. Optical fiber; 10. Optical mount; 11. Base; 12-White light filter; 13-Near infrared filter; A. Area to be inspected; B. Main optical axis; X1. First real image plane; X2. Second real image plane; X3. Third real image plane; X4. Fourth real image plane; a. Intersection point. DETAILED DESCRIPTION

[0033] In the description of the present application, it should be understood that the terms "upper", "lower", "vertical", "horizontal", "top", "bottom", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0034] The terms "first", "second", etc. are used to distinguish similar objects rather than to describe a specific order or sequence. It should be understood that the data used in this way are interchangeable where appropriate so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally of the same type, and the number of objects is not limited. For example, the first object can be one or more.

[0035] In addition, the term "and / or" in the specification and claims is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the associated objects before and after are in an "or" relationship.

[0036] In the description of the present application, unless otherwise specified, “plurality” means two or more.

[0037] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0038] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0039] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0040] Example 1

[0041] like Figure 1As shown, an optical system of a dual-mode endoscope, wherein the optical system comprises: an objective lens group 1, an eyepiece group 3 and a light controller 4 arranged in sequence along the main optical axis B, wherein the light controller 4 is used to control the propagation direction of white light and near-infrared light, the propagation direction of white light remains unchanged after passing through the light controller 4, the propagation direction of near-infrared light is changed after passing through the light controller 4, and the near-infrared light after passing through the light controller 4 enters the light conversion module;

[0042] The light conversion module comprises: a MEMS micromirror 5 and a collimating lens 6 , wherein the propagation direction of the near-infrared light is parallel to the main optical axis B after passing through the light controller 4 and the MEMS micromirror 5 in sequence.

[0043] In some embodiments, the light controller 4 is a spectrometer or an optical switch. When the light controller 4 is an optical switch, the opening and closing of the optical switch can be controlled by a program, and the interval can be in the millisecond level. This control is an existing technology that is easy to implement in this field and will not be repeated here. When the light controller 4 is a spectrometer, it can be a 5:5 spectrometer.

[0044] The optical system further includes a white light filter 12 , which is located on the image side of the light controller 4 along the direction of the main optical axis B, and is used to allow white light to pass through.

[0045] The light conversion module further includes a near infrared filter 13 , which is located between the MEMS micromirror 5 and the collimating lens 6 and is used to allow near infrared light to pass through.

[0046] In this example, the light controller 4 is a dichroic mirror, the angle between the dichroic mirror and the main optical axis B is α, 0°<α<90°, the mirror surface of the MEMS micromirror 5 is parallel to the dichroic mirror, and the angle between the optical axis of the collimating lens 6 and the mirror surface normal of the MEMS micromirror 5 is α. α can be 30°, 60°, etc., and α is preferably 45° for easy installation.

[0047] The optical system further comprises n groups of steering mirror groups 2, where n is an odd number, and the n groups of steering mirror groups 2 are located between the objective lens group 1 and the eyepiece lens group 3, and the imaging point of the last group of the steering mirror groups 2 coincides with the focus of the eyepiece lens group 3, as shown in FIG. Figure 2 As shown, the focus of the eyepiece set 3 on the object side is the imaging position of the last real image plane.

[0048] In the present application, there is no special requirement for the specific structural form of the objective lens group 1, the steering lens group 2, and the eyepiece group 3. The objective lens, eyepiece, and steering lens group used in existing white light endoscopes can be used. In this example, the objective lens group 1 includes a first glued lens group 1a and a second glued lens group 1b, which are arranged along the main optical axis B, wherein the first glued lens group 1a is close to the object side, and the second glued lens group 1b is close to the image side. The first glued lens group 1a includes a negative lens and multiple prisms, which are glued together, wherein the negative lens is close to the object side, and the prism is close to the image side. The second glued lens group 1b includes two glued lenses, such as a convex lens and a concave lens glued together.

[0049] In the present application, n=3, each steering mirror group 2 includes two steering lenses 2a arranged in parallel, the optical axis of the steering lens 2a is parallel to the main optical axis B, the steering lens 2a can be a convex lens, a concave lens, or a cemented lens. In this example, the steering lens 2a is a convex lens. There is no special requirement for the specific setting of the two steering lenses 2a in each steering mirror group 2, and they can be set according to the requirements of the optical path design. In this example, Figure 2 As shown, after the light from the farthest point above the main optical axis B and the farthest point below the main optical axis B enter the objective lens group 1, the light from the two farthest points converges at the intersection point a after passing through the first steering lens 2a of the first steering mirror group 2. The two steering lenses 2a of the first steering mirror group 2 are symmetrically arranged with the intersection point a as the center, and the optical axes of the two are parallel to the main optical axis B. The arrangement of the two steering lenses 2a in the other steering mirror groups 2 is the same.

[0050] In this example, the eyepiece group 3 is a double-cemented lens group, which is formed by cementing a concave lens and a convex lens, wherein the concave lens of the eyepiece group 3 is close to the object side, and the convex lens is close to the image side.

[0051] The collimating lens 6 includes a concave lens and a convex lens, which are glued together, wherein the concave lens of the collimating lens 6 is close to one side of the MEMS micromirror, and the convex lens of the collimating lens 6 is close to one side of the optical fiber 9.

[0052] There are no special requirements for the spacing between the first glued lens group 1a and the second glued lens group 1b, the spacing between the objective lens group 1 and the first steering lens group 2, and the spacing between the steering lens groups 2. They are generally set according to the optical setting requirements. These are easy to implement in the art and will not be elaborated here.

[0053] In some embodiments, since the dichroic mirror is disposed behind the eyepiece group 3 and the light behind the eyepiece group 3 is parallel light, there is no special requirement for the distance between the dichroic mirror and the eyepiece group 3 as long as it is easy to install.

[0054] Example 2

[0055] A dual-modality endoscopic imaging probe, comprising the optical system described in Example 1.

[0056] Furthermore, the probe also includes a first shell 8 and a second shell 7 connected to the first shell 8, wherein the objective lens group 1, the steering lens group 2 and the eyepiece group 3 are arranged in the second shell 7, and the light controller 4, the MEMS micromirror 5 and the collimating lens 6, as well as the white light filter 12 and the near-infrared filter 13 are arranged in the first shell 8. To facilitate the installation of the MEMS micromirror 5, a base 11 is also arranged in the first shell 8, and the base 11 has a 45° inclined surface, and the MEMS micromirror 5 is installed on the inclined surface of the base 11.

[0057] from Figure 1 It can also be seen that the first shell 8 is also connected to an optical fiber 9, and the focus of the collimating lens 6 is the light emission / incident point of the optical fiber 9.

[0058] The first housing 8 is connected to an optical bayonet mount 10 , and the optical bayonet mount 10 is used to connect to an adapter.

[0059] Of course, in some implementations, the light controller 4 may be installed in the second housing 7 , and an optical path exit may be opened on the second housing 7 corresponding to the near-infrared laser reflected by the light controller 4 .

[0060] The present application also discloses an endoscope, wherein the endoscope includes the probe described in Example 2.

[0061] During the inspection, an external white light source is used to illuminate the inspection area A. The propagation paths of the reflected white light and OCT light are as follows: Figure 2 As shown, the specific process is as follows:

[0062] The near-infrared laser (wavelength 800-1500nm) emitted by the optical fiber 9 is collimated into parallel light after passing through the collimating lens 6. The parallel light enters the eyepiece group 3 after being deflected by the MEMS micromirror 5 and the light controller 4, and then passes through each steering mirror group 2 and the objective lens group 1 in turn to reach the inspection area A. The light (white light or near-infrared laser) reflected by the inspection area A enters the objective lens group 1, and forms a first real image plane X1 after the objective lens group 1, and then passes through the first steering mirror group 2, the second steering mirror group 2 and the third steering mirror group 2 in turn to obtain the second real image plane X2, the third real image plane X3 and the fourth real image plane X4. After the fourth real image plane X4 enters the eyepiece group 3, the white light passes through the light controller 4 and enters the component connected to the optical bayonet 10, while the near-infrared laser is reflected by the light controller 4 and further passes through the MEMS micromirror 5, and is focused by the collimating lens 6 and enters the optical fiber 9.

[0063] The light entering the optical fiber 9 will enter the interferometer, combine with the returning light of the reference arm, generate interference, and finally be received by the detector and further analyzed. This part belongs to the existing technology in this field and will not be described here.

[0064] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various specific technical features in any appropriate manner. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations. However, these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. An optical system of a dual-modality endoscope, characterized in that: The optical system comprises: an objective lens group, an eyepiece group and a light controller which are sequentially arranged along the main optical axis direction, wherein the light controller is used to control the propagation direction of white light and near-infrared light, the propagation direction of white light remains unchanged after passing through the light controller, the propagation direction of near-infrared light is changed after passing through the light controller, and the near-infrared light after passing through the light controller enters the light conversion module; The light conversion module comprises: a MEMS micromirror and a collimating lens, wherein the propagation direction of the near-infrared light is parallel to the main optical axis after passing through the light controller and the MEMS micromirror in sequence.

2. The optical system according to claim 1, characterized in that The light conversion module further includes a near infrared filter, which is located between the MEMS micromirror and the collimating lens and is used for allowing near infrared light to pass through.

3. The optical system according to claim 1 or 2, characterized in that: The optical system further comprises a white light filter, which is located on the image side of the light controller along the direction of the main optical axis and is used to allow white light to pass through.

4. The optical system according to any one of claims 1 to 3, characterized in that: The light controller is a beam splitter or an optical switch.

5. The optical system according to any one of claims 1 to 3, characterized in that: The light controller is a dichroic mirror, and the angle between the dichroic mirror and the main optical axis is α, 0°<α<90°, and α is preferably 45°.

6. The optical system according to any one of claims 1 to 5, characterized in that: The optical system further includes n groups of steering mirror groups, where n is an odd number, and the n groups of steering mirror groups are located between the objective lens group and the eyepiece lens group, and the imaging point of the last group of the steering mirror groups coincides with the focus of the eyepiece lens group.

7. A dual-modality endoscopic imaging probe, characterized in that: An optical system comprising any one of claims 1 to 6.

8. The probe according to claim 7, characterized in that: The probe also includes a first shell and a second shell connected to the first shell, wherein the objective lens group and the eyepiece group are arranged in the second shell, the light controller and the light conversion module are arranged in the first shell, and the first shell is also connected to an optical fiber, and the near-infrared light after passing through the light conversion module is focused, and the focus is the light emission / incident point of the optical fiber.

9. The probe according to claim 8, characterized in that: The second shell is further provided with n groups of steering mirror groups, where n is an odd number, and the n groups of steering mirror groups are located between the objective lens group and the eyepiece group, and the imaging point of the last group of the steering mirror groups coincides with the focus of the eyepiece group.

10. An endoscope, characterized in that: A probe comprising any one of claims 7 to 9.

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