Endoscope catheter distal end cap for illumination and endoscope illumination system
By setting up a double concave lens at the outlet of the lighting channel of the distal end cap of the endoscope catheter, the problem of insufficient divergence angle of the illumination light is solved, and full field of view coverage and low-difficulty manufacturing is achieved, and it is suitable for narrow cavity applications.
Patent Information
- Application Number
- CN202421925613.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-09
- Publication Date
- 2025-07-22
- Estimated Expiration
- 2034-08-09
AI Technical Summary
The existing endoscope system has insufficient divergence angle of lighting, making it difficult to cover the field of view of the imaging system, resulting in poor imaging results.
A double concave lens is provided at the outlet of the lighting channel of the distal end cap of the endoscope catheter. The radius of curvature of the incoming concave surface is smaller than the radius of curvature of the outgoing concave surface, so that the illumination light is refracted twice, increasing the divergence angle to cover the entire field of view.
It realizes full field coverage within the depth of field range, meets the distal lighting requirements, and reduces the difficulty of implementing the dual concave lens, and adapts to narrow cavity applications.
Smart Images
Figure CN223126499U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the field of optical imaging, and more specifically, relates to a distal end cap for an endoscopic catheter for illumination and an endoscopic illumination system. Background Art
[0002] As a rapidly developing medical technology in recent years, the endoscope plays an extremely crucial role in the clinical diagnosis and treatment process. An endoscope system generally includes a camera system, an illumination system, a control system, a processing system, etc.
[0003] The camera system selects different resolutions and field of view angles according to the usage scenario of the endoscope. To obtain the best observation effect, the illumination range provided by the illumination system should cover the field of view area of the camera system as much as possible, and the illumination range is related to the divergence angle of the illumination light. To increase the divergence angle of the illumination light, the LED illumination method usually controls by adding a scattering agent during the production of the lamp bead diode, and the fiber optic illumination method uses a glass lens arranged at the end face of the optical fiber for control. However, the above solutions have great implementation difficulties in actual applications. Summary of the Utility Model
[0004] In view of the above defects or improvement requirements of the prior art, the utility model provides a side-view imaging component and a side-view endoscope for matching with an optical fiber probe, aiming to solve the problem of side-view imaging of the existing confocal microendoscope.
[0005] To achieve the above object, according to one aspect of the utility model, there is provided a side-view imaging component for matching with an optical fiber probe, including an end cap body. A lighting channel is arranged in the end cap body, and a biconcave lens is arranged at the lighting outlet in the lighting channel. The biconcave lens includes a light incident concave surface and a light exit concave surface, and the radius of curvature of the light incident concave surface is smaller than that of the light exit concave surface.
[0006] Through the above technical solution, a biconcave lens is arranged at the lighting outlet in the lighting channel. The illumination light will be refracted twice here, passing through the light incident concave surface and the light exit concave surface in sequence. And because the radius of curvature of the light incident concave surface is smaller than that of the light exit concave surface, the divergence angle of the illumination light after two refractions will increase, so as to cover the entire field of view within the depth of field and meet the illumination requirements at the distal end.
[0007] Further, the lighting channel is a non-through hole, and the biconcave lens is integrally formed with the end cap body.
[0008] Further, a positioning surface is arranged at the distal end of the end cap body, and the end face of the light exit concave surface coincides with the positioning surface.
[0009] Further, the end face area of the light incident concave surface is smaller than that of the light exit concave surface.
[0010] Furthermore, the central thickness of the biconcave lens is not less than 0.1 mm.
[0011] Furthermore, the diameter of the end cap body does not exceed 3.6 mm.
[0012] According to another aspect of the present invention, an endoscope illumination system is provided, including the aforementioned distal end cap of the endoscope catheter, and further including an optical fiber disposed in the illumination channel and on the light incident concave side.
[0013] Furthermore, the end face of the optical fiber is adhesively bonded to the light incident concave surface.
[0014] Furthermore, the optical fiber is a plastic optical fiber.
[0015] Generally speaking, the present invention has the following advantages:
[0016] (1) By providing a biconcave lens with the radius of curvature of the light incident concave surface smaller than that of the light exiting concave surface, the illumination light at the exit of the illumination channel can increase the divergence angle after two refractions in sequence, so as to cover the entire field of view within the depth of field and meet the illumination requirements at the distal end.
[0017] (2) The biconcave lens is formed due to the non-penetration of the illumination channel and is integrally formed with the end cap body, with lower implementation difficulty. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 is a schematic cross-sectional structure view of the distal end cap of the endoscope catheter;
[0019] Figure 2 is a schematic overall structure view of the distal end cap of the endoscope catheter;
[0020] Figure 3 is a schematic cross-sectional structure view of the endoscope illumination system.
[0021] In the figures, 1, illumination channel; 2, biconcave lens; 21, light incident concave surface; 22, light exiting concave surface; 3, positioning surface; 4, camera module channel; 5, optical fiber. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0022] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.
[0023] Such as Figure 1 and Figure 2As shown in the figure, the present utility model proposes a distal end cap of an endoscope catheter for illumination, which includes an end cap body. A lighting channel 1 is provided inside the end cap body. A double concave lens 2 is provided at the lighting outlet in the lighting channel 1. The double concave lens 2 includes a light incident concave surface 21 and a light exit concave surface 22. The radius of curvature of the light incident concave surface 21 is smaller than that of the light exit concave surface 22.
[0024] A double concave lens 2 is provided at the lighting outlet in the lighting channel 1. The lighting optical fiber 5 will undergo two refractions successively through the light incident concave surface 21 and the light exit concave surface 22 here. And because the radius of curvature of the light incident concave surface 21 is smaller than that of the light exit concave surface 22, the divergence angle of the lighting optical fiber 5 after two refractions will increase, so as to cover the entire field of view within the depth of field and meet the lighting requirements at the distal end.
[0025] The lighting channel 1 is a non-through hole, and the double concave lens 2 is integrally formed with the end cap body. Since the lighting channel 1 is a non-through hole, the double concave lens 2 integrally formed with the end cap body can be formed by processing the two side surfaces of light incident and light exit at its non-through position. Compared with custom processing a double concave lens 2 and then installing and fixing it in the lighting channel 1, the integral forming design has higher precision and lower implementation difficulty.
[0026] A positioning surface 3 is provided at the distal end of the end cap body. The end surface of the light exit concave surface 22 coincides with the positioning surface 3. The positioning surface 3 provides a positioning reference for the imaging module of the endoscope system during imaging. By arranging the light exit concave surface 22 on the positioning surface 3, it is convenient for the outgoing optical fiber 5 to cooperate with the imaging module for clear imaging.
[0027] The end surface area of the light incident concave surface 21 is smaller than that of the light exit concave surface 22. By setting the area sizes and radius of curvature sizes of the light incident concave surface 21 and the light exit concave surface 22, the purpose of increasing the divergence angle of the lighting optical fiber 5 is achieved.
[0028] A camera module channel 4 is also provided inside the end cap body. The lighting channels 1 are symmetrically distributed on both sides of the camera module channel 4. The minimum radius of curvature of the light exit concave surface 22 is determined according to the critical light rays exiting from the light exit concave surface 22, and the maximum radius of curvature of the light incident concave surface 21 is determined according to the minimum radius of curvature of the light exit concave surface 22.
[0029] The specific method for determining the minimum radius of curvature of the light-emitting concave surface 22 based on the light-emitting criticality of the light-emitting concave surface 22 is as follows: First, determine the light-emitting critical rays of the light-emitting concave surface 22 according to the field of view angle of the camera module, and determine the minimum radius of curvature of the light-emitting concave surface 22 based on the light-emitting critical rays and the central axis of the biconcave lens 2. This is because when the product is designed, the end face of the camera module will exceed the positioning surface 3, and the field of view angle of the camera module is formed by two field-of-view critical rays during shooting. According to the design requirements of the product, when the two light-emitting critical rays are respectively parallel to the two field-of-view critical rays of the camera module, first determine the light-emitting critical rays of the light-emitting concave surface 22 according to the field of view angle of the camera module. The intersection points of the two critical rays determined according to the field of view angle of the camera module and the positioning surface 3 are the light-emitting starting points of the light-emitting concave surface 22. The range of the light-emitting concave surface 22 is between the two light-emitting starting points. In some embodiments, the diameter of the end cap body is limited. Therefore, using this light-emitting starting point as a fulcrum can reduce the angle between the two light-emitting critical rays. Although this sacrifices the divergence angle of the illumination optical fiber 5, it can ensure that the diameter of the entire catheter is as small as possible; in other embodiments, the diameter of the end cap body is not limited. Therefore, using this starting point as a fulcrum can increase the angle between the two light-emitting critical rays, which can further increase the divergence angle of the illumination optical fiber 5, but will increase the diameter of the end cap body. Specifically, when the two light-emitting critical rays are respectively parallel to the two field-of-view critical rays of the camera module, the cooperation between the imaging field of view (i.e., the range where the illumination range coincides with the field of view angle of the camera module) and the diameter of the entire catheter is in an optimal match. If a larger imaging field of view is desired, the light-emitting critical ray parallel to the field-of-view critical ray of the camera module can be rotated towards the camera module with the intersection point of the light-emitting critical ray and the camera module as a fulcrum. At this time, although a larger imaging field of view can be obtained, a larger illumination range requires the illumination channel and the biconcave lens to be further away from the camera module, so the diameter of the entire catheter will increase; on the contrary, if a smaller catheter diameter is desired, then only under the requirement of ensuring the wall thickness of the catheter, try to make the illumination channel and the biconcave lens closer to the camera module. In this way, the illumination range that can coincide with the field of view angle of the camera module will become smaller, that is, compared with the case where the light-emitting critical ray is parallel to the field-of-view critical ray of the camera module, this situation shows that the light-emitting critical ray rotates away from the camera module with the intersection point of the camera module as a fulcrum. The present invention takes the case where the two light-emitting critical rays are respectively parallel to the two field-of-view critical rays of the camera module, and the cooperation between the imaging field of view (i.e., the range where the illumination range coincides with the field of view angle of the camera module) and the diameter of the entire catheter is in an optimal match as an example for illustration. At this time, the minimum radius of curvature of the light-emitting concave surface 22 determined according to the foregoing method is the minimum radius of curvature. When designing the light-emitting concave surface 22, it only needs to meet the requirement of not being less than the minimum radius of curvature.
[0030] Further, the specific method for determining the maximum radius of curvature of the light-incident concave surface 21 based on the minimum radius of curvature of the light-emitting concave surface 22 is as follows: Calculate the incident critical light rays of the light-emitting concave surface 22 from the light-emitting critical light rays of the light-emitting concave surface 22, obtain the refraction critical light rays of the light-incident concave surface 21 from the incident critical light rays of the light-emitting concave surface 22, determine the starting critical light rays of the light-incident concave surface 21 based on the starting illumination optical fiber 5 in the illumination channel 1, obtain its normal direction from the refraction critical light rays and the starting critical light rays of the light-incident concave surface 21, and determine the maximum radius of curvature of the light-incident concave surface 21 based on the intersection point of the refraction critical light rays and the starting critical light rays of the light-incident concave surface 21, the normal direction, and the central axis of the biconcave lens 2.
[0031] After the radius of curvature of the light-emitting concave surface 22 and the light-emitting critical light rays are determined, that is, the light-emitting angle α1 of the light-emitting concave surface 22 is determined. According to the law of refraction the incident angle α2 of the light-emitting concave surface 22 can be calculated, thereby determining the two incident critical light rays of the light-emitting concave surface 22. In this formula, n represents the refractive index of the biconcave lens 2, which is related to its material.
[0032] The two incident critical light rays of the light-emitting concave surface 22 are also the two refraction critical light rays of the light-incident concave surface 21, and the two starting critical light rays of the light-incident concave surface 21 are generated by the incidence of the starting illumination optical fiber 5 on this side. Therefore, the normal direction of the light-incident concave surface 21 still needs to be obtained to determine the maximum radius of curvature of the light-incident concave surface 21. According to the vector formula of the law of refraction:
[0033] the normal direction of the light-incident concave surface 21 can be solved. Among them, represents the light-emitting critical light ray vector of the light-incident concave surface 21, represents the starting critical light ray vector of the light-incident concave surface 21. In some embodiments, if there are illumination optical fibers arranged on the side of the light-incident concave surface 21, then the two starting illumination optical fibers 5 that are parallelly incident on the light-incident concave surface 21 are the starting critical light rays on the side of the light-incident concave surface 21. n A represents the refractive index on the side of the light-incident concave surface 21 in the illumination channel 1. This side is air, and the refractive index can be regarded as 1. n B represents the refractive index of the biconcave lens 2. n B =n. The material of the biconcave lens 2 is the same as that of the end cap body, usually an injection molding material. According to the above formula, given and the that can be solved is the normal vector of the light-incident concave surface 21. Based on the intersection point of the refraction critical light rays and the starting critical light rays of the light-incident concave surface 21, the normal direction, and the central axis of the biconcave lens 2, the maximum radius of curvature of the light-incident concave surface 21 can be obtained.
[0034] The central thickness of the biconcave lens 2 is not less than 0.1 mm. Since the biconcave lens 2 is integrally formed with the end cap body, controlling its central thickness can ensure the structural strength of the end cap body.
[0035] The diameter of the end cap body does not exceed 3.6 mm. The end cap body with this diameter can ensure that the entire endoscope catheter can enter the human body cavity normally.
[0036] Embodiment 1
[0037] The included angle between the two outgoing critical rays of the outgoing concave surface 22 obtained according to the field of view angle of the camera module is 121.72°. Then, combined with the central axis of the biconcave lens 2, the minimum radius of curvature of the outgoing concave surface 22 can be obtained as 6.64 mm.
[0038] After determining that the radius of curvature of the outgoing concave surface 22 is 6.64 mm, according to the outgoing critical rays of the outgoing concave surface 22, its outgoing angle α1 = 63.93° can be obtained. The refractive index n of the biconcave lens 2 is approximately 1.59. According to the law of refraction, the incident angle α2 of the outgoing concave surface 22 is calculated as 34.5°, so as to determine the two incident critical rays of the outgoing concave surface 22.
[0039] Since the two incident critical rays of the outgoing concave surface 22 are also the two refraction critical rays of the incoming concave surface 21. In this embodiment, a plastic optical fiber 5 is arranged on the incoming concave surface 21 side, and the starting critical ray of the incoming concave surface 21 is parallelly incident into the biconcave lens 2. According to the refraction critical ray vector and the starting critical ray vector of the incoming concave surface 21, the normal direction is calculated, and finally the maximum radius of curvature of the incoming concave surface 21 is obtained as 0.22 mm;
[0040] After determining that the radius of curvature of the incoming concave surface 21 is 0.22 mm, according to the starting critical ray of the incoming concave surface 21, its incident angle θ1 = 66.86° can be obtained. After refraction by the incoming concave surface 21, the outgoing angle θ2 = 35.43°. After verification
[0041] The central thickness of the biconcave lens 2 designed in this embodiment is 0.1 mm. The central axis of the biconcave lens 2 is spaced 0.97 mm from the central axis of the camera module channel 4. The diameter of the entire end cap body is small, which can meet the application requirements for passing through narrow cavities.
[0042] Embodiment 2
[0043] The included angle between the two outgoing critical rays of the outgoing concave surface 22 obtained according to the field of view angle of the camera module is 122.93°. Then, combined with the central axis of the biconcave lens 2, the minimum radius of curvature of the outgoing concave surface 22 can be obtained as 1.17 mm.
[0044] After determining that the radius of curvature of the light-emitting concave surface 22 is 1.17 mm, according to the critical light rays emitted from the light-emitting concave surface 22, the light-emitting angle α1 = 76.42° can be obtained. The refractive index n of the biconcave lens 2 is approximately 1.59. According to the law of refraction, the incident angle α2 of the light-emitting concave surface 22 is calculated to be 37.8°, thereby determining the two incident critical light rays of the light-emitting concave surface 22.
[0045] Since the two incident critical light rays of the light-emitting concave surface 22 are also the two refracted critical light rays of the light-incident concave surface 21, in this embodiment, a plastic optical fiber 5 is provided on the side of the light-incident concave surface 21, and the starting critical light ray of the light-incident concave surface 21 is parallelly incident into the biconcave lens 2. The normal direction is calculated based on the refracted critical light ray vector and the starting critical light ray vector of the light-incident concave surface 21, and finally the maximum radius of curvature of the light-incident concave surface 21 is obtained as 0.25 mm;
[0046] After determining that the radius of curvature of the light-incident concave surface 21 is 0.25 mm, according to the starting critical light ray of the light-incident concave surface 21, its incident angle θ1 = 53.13° can be obtained. After being refracted by the light-incident concave surface 21, the light-emitting angle θ2 = 30.29°. After verification
[0047] The central thickness of the biconcave lens 2 designed in this embodiment is 0.1 mm. The central axis of the biconcave lens 2 is spaced 0.92 mm from the central axis of the camera module channel 4. The diameter of the entire end cap body is small, which can meet the application requirements for passing through narrow channels.
[0048] Embodiment 3
[0049] The included angle between the two light-emitting critical light rays of the light-emitting concave surface 22 obtained according to the field of view angle of the camera module is 125.81°. Then, in combination with the central axis of the biconcave lens 2, the minimum radius of curvature of the light-emitting concave surface 22 is obtained as 0.71 mm.
[0050] After determining that the radius of curvature of the light-emitting concave surface 22 is 0.71 mm, according to the critical light rays emitted from the light-emitting concave surface 22, the light-emitting angle α1 = 85.12° can be obtained. The refractive index n of the biconcave lens 2 is approximately 1.59. According to the law of refraction, the incident angle α2 of the light-emitting concave surface 22 is calculated to be 38.92°, thereby determining the two incident critical light rays of the light-emitting concave surface 22.
[0051] Since the two incident critical light rays of the light-emitting concave surface 22 are also the two refracted critical light rays of the light-incident concave surface 21, in this embodiment, a plastic optical fiber 5 is provided on the side of the light-incident concave surface 21, and the starting critical light ray of the light-incident concave surface 21 is parallelly incident into the biconcave lens 2. The normal direction is calculated based on the refracted critical light ray vector and the starting critical light ray vector of the light-incident concave surface 21, and finally the maximum radius of curvature of the light-incident concave surface 21 is obtained as 0.3 mm;
[0052] After determining that the radius of curvature of the light-incident concave surface 21 is 0.3 mm, according to the initial critical ray of the light-incident concave surface 21, the incident angle θ1 = 41.28° can be obtained. After refraction by the light-incident concave surface 21, the outgoing light angle θ2 = 24.58°. After verification
[0053] The central thickness of the double concave lens 2 designed in this embodiment is 0.1 mm. The central axis of the double concave lens 2 is spaced 0.89 mm from the central axis of the camera module channel 4. The diameter of the entire end cap body is small, which can meet the application requirements for passing through narrow channels.
[0054] The present utility model also proposes an endoscope illumination system, as Figure 3 shown, which includes the aforementioned distal end cap of the endoscope catheter, and also includes an optical fiber disposed in the illumination channel 1 and on the side of the light-incident concave surface 21. In the LED illumination method adopted in the prior art, the volume of the LED lamp bead limits the layout of other channels or systems, and the LED lamp bead cannot be directly exposed, but can only be installed inside the end cap body, which makes the light-emitting surface lower than the camera plane, and the part irradiated on the camera module will generate shadows in the field of view. The present utility model places the optical fiber on the side of the light-incident concave surface 21 in the illumination channel 1, and transmits the illumination light through the optical fiber, which can meet the application in an endoscope with a smaller diameter. At the same time, through the design of the double concave lens 2, it can also ensure that there is no shadow generated in the entire field of view when the camera module takes pictures.
[0055] The end face of the optical fiber is adhesively bonded to the light-incident concave surface 21. The optical fiber is a plastic optical fiber. The bonding and grinding processes of glass optical fibers are complex, and filament breakage is likely to occur during the processing, affecting the final illumination effect. The present utility model adopts a plastic optical fiber, which can reduce the cost of the endoscope and improve the manufacturability of production. However, the divergence angle of the plastic optical fiber is only 70°, but under the two refractions of the double concave lens 2, the divergence angle can be increased, so as to match the camera module with a large field of view angle.
[0056] It is easy for those skilled in the art to understand that the above are only the preferred embodiments of the present utility model, and are not used to limit the present utility model. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.
Claims
1. A distal end cap of an endoscope catheter for illumination, characterized in that, It includes an end cap body, and an illumination channel is provided in the end cap body. A double concave lens is provided at the illumination outlet in the illumination channel. The double concave lens includes a light incident concave surface and a light exiting concave surface, and the radius of curvature of the light incident concave surface is smaller than that of the light exiting concave surface.
2. The distal end cap of the endoscope catheter according to claim 1, wherein The illumination channel is a non-through hole, and the double concave lens is integrally formed with the end cap body.
3. The distal end cap of the endoscope catheter according to claim 1, wherein A positioning surface is provided at the distal end of the end cap body, and the end surface of the light exiting concave surface coincides with the positioning surface.
4. The distal end cap of the endoscopic catheter according to claim 2, characterized in that, The end surface area of the light incident concave surface is smaller than that of the light exiting concave surface.
5. The distal end cap of the endoscope catheter according to claim 4, characterized in that, The central thickness of the double concave lens is not less than 0.1 mm.
6. The distal end cap of the endoscope catheter according to claim 4, characterized in that The diameter of the end cap body does not exceed 3.6 mm.
7. An endoscope lighting system, characterized in that, It includes the distal end cap of the endoscope catheter as described in any one of claims 1-6, and further includes an optical fiber disposed in the illumination channel and on the side of the light incident concave surface.
8. The endoscope illumination system according to claim 7, wherein The end surface of the optical fiber is adhesively bonded to the light incident concave surface.
9. The endoscope illumination system according to claim 8, characterized in that, The optical fiber is a plastic optical fiber.