Near-infrared endocytoscope and objective lens thereof

Abstract

A near-infrared endocytoscope and an objective lens (30) thereof. The objective lens (30) comprises: a diaphragm (130); and a first lens group and a second lens group respectively arranged on an object side and an image side relative to the diaphragm (130). The first lens group comprises at least one first variable focal length lens (301) and a plurality of first fixed focal length lenses (112, 113). The second lens group comprises at least one second variable focal length lens (302) and a plurality of second fixed focal length lenses (121, 122). On the basis of the objective lens (30) and the near-infrared endocytoscope, the variable focal length lenses can be independently and continuously adjusted to complete continuous scanning and imaging of tissues inside the human body.

Description

Near-infrared cell microendoscopy and its objective lens Technical Field

[0001] This disclosure relates to the field of optical lens technology, and in particular to a near-infrared cell microendoscopy and its objective lens. Background Technology

[0002] Endocytoscopes combine the functions of endoscopy and microscopy, enabling high-resolution microscopic observation inside living organisms and direct microscopic imaging of living tissues. Through endoscopic microscopy, cellular structure and tissue morphology can be clearly displayed, which is of great significance for disease diagnosis and treatment. For example, in the early diagnosis of tumors, endoscopic microscopy allows direct observation of the morphology and number of tumor cells, thereby improving diagnostic accuracy.

[0003] However, existing cellular microendoscopy relies on external mechanical movements to adjust the focal length and can only achieve observation and optical imaging of the skin surface or the epidermis of internal tissues. It cannot scan or perform optical imaging of the skin surface or the subepidermis of internal tissues. Summary of the Invention

[0004] In view of this, embodiments of this application provide a near-infrared cell microscopic endoscope and its objective lens to address the pain points of existing cell microscopic endoscope products.

[0005] In a first aspect, embodiments of this disclosure provide an objective lens for a near-infrared cell microscopy endoscope, comprising:

[0006] Aperture; and

[0007] The first lens group and the second lens group are respectively disposed on the object side and the image side relative to the aperture stop.

[0008] The first lens group includes at least one first variable focal length lens and a first plurality of fixed focal length lenses, and the second lens group includes at least one second variable focal length lens and a second plurality of fixed focal length lenses.

[0009] In some embodiments, the at least one first variable focal length lens and the at least one second variable focal length lens are liquid lenses.

[0010] In some embodiments, the objective lens further includes a visible light cutoff filter that blocks visible light and allows near-infrared light to pass through.

[0011] In some embodiments, at least a portion of the first plurality of fixed-focal-length lenses and the second plurality of fixed-focal-length lenses are coated with a near-infrared anti-reflection film by vapor deposition.

[0012] In some embodiments, the at least one first variable focal length lens is closer to the object side than the first plurality of fixed focal length lenses, and the at least one second variable focal length lens is closer to the image side than the second plurality of fixed focal length lenses.

[0013] In some embodiments, the radius of curvature and focal length of the liquid lens change when different voltages are applied.

[0014] In some embodiments, the first lens group and the second lens group have the same number of variable focal length lenses, and / or the first lens group and the second lens group have the same number of fixed focal length lenses.

[0015] In some embodiments, the thickness of the container glass in the liquid lens is 0.50000 mm.

[0016] In some embodiments, the driving film in the liquid lens has a refractive index of 1.41, an Abbe value of 49.9, and a thickness of 0.05000 mm.

[0017] In some embodiments, the thickness of the optical liquid in the liquid lens is 0.68404 mm or 684 micrometers.

[0018] In some embodiments, the first lens film in the liquid lens has a refractive index of 1.41, an Abbe value of 49.9, a radius of curvature of 306.49095 mm, and a thickness of 0.05000 mm.

[0019] In some embodiments, the first lens film in the liquid lens has a refractive index of 1.41, an Abbe value of 49.9, a radius of curvature of 306.49095 mm, and a thickness of 1.22596 mm.

[0020] Secondly, embodiments of this disclosure provide a near-infrared cell microscopy endoscope, comprising:

[0021] Objective lens as described in any of the above;

[0022] Image sensor;

[0023] A driving component for applying an external force to the at least one first variable focal length lens and / or the at least one second variable focal length lens to adjust the focal length of the at least one first variable focal length lens and / or the at least one first variable focal length lens.

[0024] In some embodiments, the driving component adjusts the focal length of the at least one first variable focal length lens and the at least one second variable focal length lens, respectively.

[0025] Thirdly, embodiments of this disclosure provide a scanning imaging method, including:

[0026] Provide the above-mentioned near-infrared cell microscopy endoscope; and

[0027] The focal length of the objective lens is continuously adjusted by the drive component so that the image sensor can scan and image tissues at different depths below the epidermis.

[0028] The near-infrared cell microscopy endoscope and objective lens provided in this disclosure adjust the radius of curvature and focal length of the variable focal length lens in the objective lens through external action. Since these external actions do not require mechanical movement, continuous operation can be performed to complete continuous scanning and imaging of the observed object. Furthermore, the first variable focal length lens is positioned closest to the object side, and the second variable focal length lens is positioned closest to the image side (i.e., the image sensor). When an external action is applied to the first or second variable focal length lens, its radius of curvature and focal length change, correspondingly altering the working distance between the objective lens and the skin surface or the epidermis of internal tissue, or the distance between the objective lens and the image sensor, thereby achieving scanning and imaging at different magnifications. In addition, a visible light cutoff filter is provided in the objective lens to utilize the strong penetrating power of the near-infrared beam into the skin and tissue, enabling continuous scanning and imaging of subcutaneous tissue at different depths in the near-infrared spectral band, and thus forming a 3D reconstructed image. Attached Figure Description

[0029] The above and other objects, features and advantages of the present disclosure will become clearer from the following description of embodiments of the present disclosure with reference to the accompanying drawings, in which:

[0030] Figures 1A to 1C and Figures 2A to 2C are schematic diagrams of fixed focal length lenses and variable focal length lenses;

[0031] Figure 3 is a schematic diagram of the structure of a near-infrared cell microendoscopy provided in an embodiment of the present disclosure;

[0032] Figure 4 is a schematic diagram of an example of the objective lens 30 in Figure 3;

[0033] Figure 5 shows a schematic diagram of the structure of a near-infrared cell microendoscopy endoscope having the same concept as the near-infrared cell microendoscopy endoscope of Figure 3, but providing more details, according to an embodiment of the present disclosure. Detailed Implementation

[0034] To better understand this disclosure, various aspects of this disclosure will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely illustrative of exemplary embodiments of this disclosure and are not intended to limit the scope of this disclosure in any way. Throughout the specification, the same reference numerals refer to the same elements.

[0035] In this document, the terms "first," "second," etc., are used only to distinguish features, components, entities, parts, etc., and do not imply any limitation on the described targets. When the terms "including," "comprising," and / or "having" are used in the description, it indicates that the described targets include the mentioned targets, but does not exclude the existence of other unmentioned targets.

[0036] Before introducing the various embodiments of this disclosure, let's first introduce some terminology and related knowledge.

[0037] An objective lens is a lens group composed of several lenses. The purpose of using lens groups is to overcome the imaging defects of a single lens and improve the optical quality of the objective lens.

[0038] Figures 1A to 1C and Figures 2A to 2C are schematic diagrams of fixed-focal-length lenses and variable-focal-length lenses. Figures 1A to 1C show a fixed-focal-length concave lens, a plane mirror, and a convex lens, respectively, in which the shape determines the focal length and optical power. Figures 2A to 2C are example diagrams of variable-focal-length lenses. In Figures 2A to 2C, the variable-focal-length lens is a liquid lens, where different voltages are applied to the liquid lens to change the shape of the liquid droplet, thereby changing the radius of curvature of the lens and the focal length and optical power of the lens.

[0039] Figure 3 is a schematic diagram of the structure of a near-infrared cell microscopy endoscope provided in an embodiment of this disclosure. As shown in the figure, the near-infrared cell microscopy endoscope includes a protective cover plate 70, an objective lens 30, a drive component 40, and an image sensor 50. The protective cover plate 70 is disposed between the first lens of the objective lens 30 and the object being observed, and is used to protect the first lens of the objective lens from wear. The outermost layer of the protective cover plate 70 typically overlaps with the object-side surface so that the objective lens can be in close contact with the tissue surface for observation. The cover plate 70 can be made of sapphire glass with good abrasion resistance. The objective lens 30 includes a variable focal length lens 301, a lens group 303, a variable focal length lens 302, and a filter 60 disposed along the object side to the image side. The driving component 40 changes the focal length and optical power of lenses 301 and 302 by applying external forces to them, thereby changing the focal length and optical power of objective lens 30. Variable focal length lens 301 and variable focal length lens 302 are, for example, liquid lenses, and the focal length and optical power of the liquid lenses are changed by applying different voltages.

[0040] Lens group 303 includes multiple lenses disposed on both sides of the aperture stop, and each lens in lens group 303 has a fixed focal length. A filter 60 is disposed between the objective lens 30 and the image sensor 50 on the image side. The filter 60 is used to filter light beams of a certain wavelength band while allowing light beams of other wavelength bands to pass through. The filter 60 is, for example, a near-infrared cutoff filter. The function of the near-infrared cutoff filter is to filter out infrared light beams introduced by ambient light sources, allowing only visible light (e.g., visible light with a wavelength of approximately 400-700 nanometers) to pass through and reach the image sensor 50 itself.

[0041] According to this embodiment, the driving component 40 applies external forces to the lenses 301 and 302 respectively to change the radius of curvature of the lenses 301 and 302, thereby changing the focal length of the objective lens 30 and changing the working distance between the entire objective lens 30 and the surface of the object being observed. Since these changes do not require mechanical action, it is convenient to continuously perform these changes and complete the continuous scanning and imaging of the surface of the object being observed.

[0042] In a further embodiment, filter 60 is a visible light cutoff filter used to filter out visible light and utilize near-infrared light for continuous scanning and imaging. Since near-infrared beams have strong penetrating power into skin and tissue, continuous scanning and imaging of subcutaneous tissue at different depths in the near-infrared spectral band is possible. These scans and imaging provide a means for 3D reconstruction images after near-infrared cellular-level optical imaging of subcutaneous tissue. Taking Figure 3 as an example, by applying external forces to lenses 301 and 302, the entire objective lens scans and images layers at different depths within 1 mm below the epidermis of the observed object on the object side. Thus, this embodiment, by combining a visible light cutoff filter with a variable focal length lens, enables scanning and imaging of layers at different depths below the epidermis of the observed object on the object side in the near-infrared spectral band, and provides a means for 3D reconstruction images after near-infrared cellular-level optical imaging of subcutaneous tissue.

[0043] In a further embodiment, the near-infrared cellular microendoscopy includes two objectives implemented according to the above embodiments. The two objectives each have completely different parameters and physical characteristics. However, one of the objectives includes a visible light cutoff filter to scan and image subcutaneous tissue using near-infrared light. The other objective includes a near-infrared cutoff filter to scan and image surface tissue using visible light. In addition, the near-infrared cellular microendoscopy may also include a wide-angle lens for screening areas that need to be observed by cytoscopy.

[0044] In a further embodiment, one or more lenses in the lens group 303 are coated with a near-infrared anti-reflection film. The use of the near-infrared anti-reflection film enhances the intensity of transmitted near-infrared light, so as to better scan and image layers at different depths under the surface of the object being observed in the near-infrared spectral band.

[0045] In a further embodiment, the objective lens 30 shown in FIG3 includes at least one variable focal length lens 301 and at least one variable focal length lens 302. Each variable focal length lens 301 is closer to the object side than the other lenses, and each variable focal length lens 302 is closer to the image side than the other lenses. The driving component 40 can independently apply an external action to each variable focal length lens to change the radius of curvature and focal length of each variable focal length lens respectively. The radius of curvature and focal length of which variable focal length lens can be determined according to actual needs. For example, the radius of curvature and focal length of the variable focal length lens 301 closest to the object side can be changed, thereby changing the working distance between the objective lens and the skin surface or the epidermis of the body tissue; as another example, the radius of curvature and focal length of the variable focal length lens 302 closest to the image side can be changed, thereby changing the distance between the objective lens and the image sensor.

[0046] In a further embodiment, although the objective lens 30 shown in FIG3 includes at least one variable focal length lens 301 and at least one variable focal length lens 302, each variable focal length lens 301 and each variable focal length lens 302 are respectively disposed closer to the two sides of the aperture stop, while the plurality of fixed focal length lenses in the lens group 303 are respectively disposed closer to the object side and the image side.

[0047] In a further embodiment, as shown in FIG3, in the objective lens 30, the first group of lenses and the second group of lenses on both sides of the aperture stop each include the same number of variable focal length lenses, and / or, the first group of lenses and the second group of lenses on both sides of the aperture stop each include the same number of fixed focal length lenses. For example, in FIG3, there is one variable lens on each side of the aperture stop, and the number of fixed focal length lenses located on both sides of the aperture stop in the lens group 303 is, for example, 1, 2, 3, etc.

[0048] In a further embodiment, as shown in Figure 3, the objective lens 30 can be a spherical lens or a (double-sided or single-sided) aspherical lens. Furthermore, the lens can be fabricated using various materials and processes, including plastic, glass, or a glass-plastic hybrid, and wafer-level optics. In some industrial implementations, some or all of the lenses are made of plastic. Compared to glass, plastic has poorer thermal stability and compressive strength; however, the biggest advantages of plastic aspherical lenses are their low cost, light weight, and ease of molding, making them suitable for disposable lens applications.

[0049] Furthermore, the near-infrared cell microendoscopy provided in this disclosure embodiment can also be implemented by using the original optical design architecture of the visible light cell microendoscopy and making appropriate changes, so as to make full use of the low-cost advantage of changing the beam band range. This includes adjusting the image sensor based on the original visible light band image sensor to achieve the low cost obtained by the image sensor of this disclosure embodiment, and the objective lens itself can also be made of relatively low-cost optical plastic with good penetration in the near-infrared band, so as to achieve low-cost manufacturing.

[0050] Figure 4 is a schematic diagram of an example of the objective lens 30 in Figure 3. In this example, the objective lens 30 includes a first lens group, a second lens group, and a filter 60 disposed on both sides of the aperture stop 130. The first lens group includes a variable focal length lens 301, fixed focal length lenses 112 and 113 arranged sequentially from the object side to the aperture stop, and the second lens group includes fixed focal length lenses 121 and 122 and a variable focal length lens 302 arranged sequentially from the aperture stop to the image side.

[0051] In the figure, lenses 112 to 113 and lenses 121 to 122 can be convex lenses, concave lenses, or partially convex and partially concave lenses; lenses 112 to 113 and lenses 121 to 122 can be (double-sided) aspherical lenses, spherical lenses, or partially (double-sided) aspherical lenses and partially spherical lenses; the various parameters of lenses 112 to 113 and lenses 121 to 122 can be symmetrically distributed according to aperture 130, but may not be symmetrically distributed according to aperture 130. In summary, this example does not impose specific restrictions on the lens type, lens shape, lens parameters, etc. of lenses 112 to 113 and lenses 121 to 122.

[0052] Figure 5 shows a schematic diagram of a near-infrared cell microscopy endoscope 500 that shares the same concept as the near-infrared cell microscopy endoscope of Figure 3 but provides more details, according to an embodiment of this disclosure. Referring to Figure 5, the near-infrared cell microscopy endoscope 500 includes a protective cover plate 70, an objective lens 80, a drive unit 40, and an image sensor 50. The objective lens 80 includes a filter 60. The protective cover plate 70, drive unit 40, image sensor 50, and filter 60 are all described above with reference to Figure 3. The objective lens 80 also includes a first lens group and a second lens group disposed on both sides of an aperture 550. The first lens group includes a liquid lens 520 and fixed-focus lenses 511 to 513. The second lens group includes fixed-focus lenses 521 to 523 and a liquid lens 530. The first and second lens groups are symmetrical about the shape of the aperture 550, and the liquid lenses 520 and 530 are also symmetrical about the shape of the aperture 550. Both liquid lenses 520 and 530 are composed of multi-layered structures. Figure 5 shows several components of liquid lens 520, including but not limited to a housing (not shown), container glass 1, driving film 2, optical liquid 3, lens films 4 and 5, glass cover plate 6, and air gap 7. Table 1 provides the parameter specifications for the various components of liquid lens 520.

[0053] Table 1

[0054] Material Function Radius of Curvature Material Material Thickness Shell Inifinity 1.30000 mm Container Glass 1 Inifinity H-K9L (a high-transparency optical glass) 0.50000 mm Driving Film 2 Inifinity 1.41,49.9 (refractive index and Abbe number of the material) 0.05000 mm or 50 microns Optical Liquid 3 Inifinity OL1224 (a specific type of optical liquid) 0.68404 mm or 684 microns Lens film 4306.49095 mm 1.41, 49.9 (refractive index and Abbe number of the material) 0.05000 mm or 50 microns lens film 5306.49095 mm 1.41, 49.9 (refractive index and Abbe number of the material) 1.22596 mm glass cover 6 Inifinity H-K9L (a high-transparency optical glass) 0.30000 mm gap 7 0.09000 mm housing Inifinity 0.50000 mm

[0055] In Table 1, the radius of curvature "Infinity" typically indicates that the interface is planar. The refractive index and Abbe number of a material are important parameters in optical design, affecting the refraction and dispersion of light. The numbers in the table correspond to the interfaces marked with different symbols in the magnified diagram, while the third column lists the materials used for each interface.

[0056] Based on the embodiment in Figure 5, this application also provides more embodiment variations. For example, the lens groups on both sides of the aperture are not symmetrically arranged, such as one of the following three options: the liquid lenses on both sides of the aperture are symmetrically arranged, but the fixed focal length lenses on both sides of the aperture are asymmetrically arranged; the liquid lenses on both sides of the aperture are symmetrically arranged, but the fixed focal length lenses on both sides of the aperture are asymmetrically arranged; the liquid lenses on both sides of the aperture are asymmetrically arranged, but the fixed focal length lenses on both sides of the aperture are symmetrically arranged.

[0057] In summary, when constructing an objective lens product, two basically symmetrical lens groups can be first set on both sides of the aperture stop. Then, a variable focal length lens can be set on each side of the aperture stop near the object side and the image side. By applying different external actions to the variable focal length lens, the various parameters of the objective lens can be finely adjusted. Accordingly, this disclosure also provides a scanning imaging method, which includes using the above-mentioned near-infrared cell microscopy endoscope, continuously applying external actions to the variable focal length lens through a driving component to adjust the focal length of the objective lens, and using the strong penetrating power of the near-infrared beam to the skin and tissues to achieve continuous scanning and imaging of tissues at different layers and depths inside the epidermis or human body, thereby forming a 3D reconstructed image.

[0058] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the embodiments of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0059] The above description is merely a preferred embodiment of this disclosure and is not intended to limit the embodiments of this disclosure. Unless otherwise specified, the above embodiments and features can be combined with each other. For those skilled in the art, various modifications and variations can be made to the embodiments of this disclosure. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the protection scope of the embodiments of this disclosure.

Claims

1. An objective lens for a near-infrared cell microscopy endoscope, comprising: Aperture; as well as The first lens group and the second lens group are respectively disposed on the object side and the image side relative to the aperture stop. The first lens group includes at least one first variable focal length lens and a first plurality of fixed focal length lenses, and the second lens group includes at least one second variable focal length lens and a second plurality of fixed focal length lenses.

2. The objective lens according to claim 1, wherein, The at least one first variable focal length lens and the at least one second variable focal length lens are liquid lenses.

3. The objective lens according to claim 1 or 2, further comprising: Visible light cutoff filter, used to block visible light.

4. The objective lens according to any one of claims 1 to 3, wherein, At least a portion of the first plurality of fixed-focal-length lenses and the second plurality of fixed-focal-length lenses have near-infrared anti-reflection coatings deposited on their surfaces.

5. The objective lens according to claim 1, wherein, The at least one first variable focal length lens is closer to the object side than the first plurality of fixed focal length lenses, and the at least one second variable focal length lens is closer to the image side than the second plurality of fixed focal length lenses.

6. The objective lens according to claim 2, wherein, The radius of curvature and focal length of the liquid lens change when different voltages are applied.

7. The objective lens according to claim 1, wherein, The first lens group and the second lens group have the same number of variable focal length lenses, and / or the first lens group and the second lens group have the same number of fixed focal length lenses.

8. The objective lens according to claim 2, wherein, The thickness of the container glass in the liquid lens is 0.50000 mm.

9. The objective lens according to claim 2, wherein, The driving film in the liquid lens has a refractive index of 1.41, an Abbe value of 49.9, and a thickness of 0.05000 mm.

10. The objective lens according to claim 2, wherein, The first lens film in the liquid lens has a refractive index of 1.41, an Abbe value of 49.9, a radius of curvature of 306.49095 mm, and a thickness of 0.05000 mm.

11. The objective lens according to claim 2, wherein, The first lens film in the liquid lens has a refractive index of 1.41, an Abbe value of 49.9, a radius of curvature of 306.49095 mm, and a thickness of 1.22596 mm.

12. The objective lens according to claim 2, wherein, The thickness of the optical liquid in the liquid lens is 0.68404 mm or 684 micrometers.

13. A near-infrared cell microendoscopy system, comprising: The objective lens as described in any one of claims 1 to 12; Image sensor; A driving component for applying an external force to the at least one first variable focal length lens and / or the at least one second variable focal length lens to adjust the focal length of the at least one first variable focal length lens and / or the at least one first variable focal length lens.

14. The near-infrared cell microscopy endoscope according to claim 8, wherein, The driving component adjusts the focal length of the at least one first variable focal length lens and the at least one second variable focal length lens respectively.

15. A scanning imaging method, comprising: Provide the near-infrared cell microscopy endoscope as described in claim 14; as well as The focal length of the objective lens is continuously adjusted by the driving component to enable the image sensor to continuously scan and image tissues at different depths below the epidermis.

Images