A polarized illumination system, a polarized imaging system, and an endoscope system

Abstract

The first aspect of this invention provides a polarized illumination system for providing illumination light to biological tissue, comprising at least one laser, a lens, and a polarization-maintaining fiber. The second aspect provides a polarized imaging system for receiving light reflected or scattered by biological tissue after illumination, comprising an analyzer, an imaging lens, and a photosensitive device. The third aspect provides another polarized imaging system, comprising an imaging lens, a polarizing beam splitter, and a photosensitive device. The fourth aspect provides an endoscope system comprising the aforementioned polarized illumination system and polarized imaging system. This invention utilizes the different depolarization characteristics of scattered light at different depths to achieve separate imaging of specular reflection light, surface scattered light, and deep scattered light, greatly improving the visibility of mucosal surface and deep mucosal information, and significantly enhancing the visibility of various mucosal lesions.

Description

Technical Field

[0001] This invention belongs to the field of endoscope technology, specifically a polarized illumination system, a polarized imaging system, and an endoscope system. Background Technology

[0002] Diseases of the digestive, respiratory, and urinary systems in the human body can cause changes in related biological tissues (such as mucous membranes). To highlight lesions, endoscopes typically use multispectral illumination and pigment spraying to enhance the mucosal surface structure, highlight the superficial and underlying blood vessels of the mucosa, and increase the difference between the lesion area and normal tissue. However, the detection rate for small superficial mucosal lesions and flat lesions remains low.

[0003] When an endoscopic light source illuminates human tissue, the illumination light is reflected or scattered by the surface and deep layers of the biological tissue. The light reflected or scattered by different layers contains corresponding information. Current endoscopes cannot process the information from each layer separately. By forcibly using image algorithms to stretch colors and enhance structures, they easily miss tiny protrusions and depressions on the mucosal surface and subtle color differences within the tissue, thus making it impossible to detect minute lesions. Summary of the Invention

[0004] To address the aforementioned problems, a first aspect of the present invention provides a polarized illumination system for providing illumination light to irradiate biological tissues, comprising at least one laser, a lens, and a polarization-maintaining fiber; polarized light emitted from the laser is coupled through the lens and enters the polarization-maintaining fiber, and illumination light is emitted from the polarization-maintaining fiber.

[0005] When an endoscopic light source irradiates human tissue, a portion of the light undergoes direct specular reflection. The polarization state of this specularly reflected light is the same as the incident light, and no depolarization occurs. This portion of the specularly reflected light carries information about the mucosal surface. Another portion of the light is incident on the surface of the mucosal tissue and undergoes a small amount of scattering. The polarization state of this scattered light undergoes a small amount of depolarization and carries a large amount of information about the mucosal surface and a small amount of information about the deeper mucosa. A third portion of the light penetrates deep into the mucosal tissue and undergoes extensive scattering. This scattered light undergoes significant depolarization and carries a large amount of information about the deeper mucosa, containing almost no information about the mucosal surface. This invention uses a laser as the light source to irradiate biological tissue. Because the laser's output light is polarized, after reflection or scattering by the biological tissue, the incident polarized light undergoes varying degrees of depolarization, thereby obtaining corresponding information from different layers of biological tissue and improving the detection rate of lesions.

[0006] In some embodiments, the polarization illumination system further includes at least one polarization controller disposed at at least one of the following locations: between the laser and the lens, between the lens and the polarization-maintaining fiber, in the polarization-maintaining fiber, and after the polarization-maintaining fiber.

[0007] When a polarization illumination system has multiple lasers, the light sources can be arranged in combination with dichroic mirrors so that the emitted light from multiple lasers is ultimately in the same optical path. In this case, the polarization controller can be set between each laser and the corresponding dichroic mirror, or between a lens and a dichroic mirror adjacent to the lens.

[0008] When the polarization controller is set in the polarization-maintaining fiber, two polarization-maintaining fibers can be used, and the polarization controller is placed between the two polarization-maintaining fibers.

[0009] Polarization-maintaining fibers can be single-polarization-maintaining fibers or double-polarization-maintaining fibers. Single-polarization-maintaining fibers transmit laser light in only one polarization direction and maintain the polarization performance of the laser light. Double-polarization-maintaining fibers can transmit laser light in both the fast and slow axes of the fiber simultaneously and maintain the polarization performance of the laser light.

[0010] In some implementations, by using a polarization controller, the polarization illumination system can provide two types of illumination light with different polarization directions, in which case a dual polarization-maintaining fiber can be selected.

[0011] In some implementations, the laser in a polarized illumination system can be replaced with one of the following: an LED (Light-emitting Diode), a xenon lamp, or an SLD (Superluminescent Diode). The polarization-maintaining fiber is replaced with a non-polarization-maintaining fiber. The polarized illumination system also includes a polarizer, which is positioned after the non-polarization-maintaining fiber. The emitted light from the LED, xenon lamp, or SLD is coupled through a lens into the non-polarization-maintaining fiber and then converted into polarized light by the polarizer. When ordinary light sources such as LEDs, xenon lamps, or SLDs are used in the polarized illumination system, the emitted light is unpolarized. Correspondingly, the polarization-maintaining fiber needs to be replaced with ordinary illumination fiber to ensure that light in all polarization directions can pass through the fiber, maintaining brightness, before being converted into polarized light by the polarizer.

[0012] A second aspect of the present invention provides a polarization imaging system for receiving light reflected or scattered by biological tissue after being irradiated by illumination light, including an analyzer, an imaging lens and a photosensitive device. The reflected or scattered light passes through the analyzer to obtain polarized light consistent with the polarization direction of the analyzer, and then passes through the imaging lens to enter the photosensitive device to obtain an image.

[0013] Alternatively, an analyzer can be placed in front of the photosensitive device to form a polarization photosensitive device. The reflected or scattered light passes through the imaging lens and enters the polarization photosensitive device to obtain an image.

[0014] Unpolarized specular reflection and a small amount of polarized scattered light carry information about the surface structure of the mucosa, superficial capillaries, and other substances in the mucosa; however, this information is considered noise for the deeper layers of the mucosa. Conversely, a large amount of polarized scattered light carries information about the large blood vessels in the submucosal layer and other substances in the submucosal layer; this information is also considered noise for the surface layers of the mucosa. In polarization imaging systems, an analyzer is used to convert the light entering the photosensitive device into light with a specific polarization direction, thereby removing noise and obtaining information about the biological tissue at the desired target layer.

[0015] In a polarization imaging system, multiple sets of analyzers and photosensitive devices can be used as needed to obtain images formed by light with different polarization directions, thereby obtaining information about biological tissues at different levels.

[0016] In some implementations, when the polarization direction is at 0-45° to the polarization direction of the illumination light, the image contains surface information of the biological tissue; when the polarization direction is at 45-90° to the polarization direction of the illumination light, the image contains deep information of the biological tissue.

[0017] By utilizing the different depolarization properties of scattered light at different depths, and adjusting the angle between the polarization direction and the illumination light's polarization direction, specular reflection, surface scattered light, and deep scattered light can be imaged separately. This significantly improves the visibility of both surface and deep mucosal information, greatly enhancing the visibility of various mucosal lesions. As the angle between the polarization direction and the illumination light's polarization direction gradually increases, the image contains information about deeper biological tissues. When the polarization direction forms a 90° angle with the illumination light's polarization direction, specular reflection from the mucosal surface can be isolated. This is particularly advantageous and yields more accurate results for imaging parameters such as mucosal blood oxygen content and mucosal hemoglobin content, which only require scattered light.

[0018] A second aspect of the present invention also provides another polarization imaging system, including an imaging lens, a polarization beam splitter, and a photosensitive device. Reflected or scattered light passes through the imaging lens and is then separated by the polarization beam splitter to obtain polarized light with a preset polarization direction. The polarized light with the preset polarization direction enters the photosensitive device to obtain an image.

[0019] In some implementations, when the preset polarization direction is 0-45° to the polarization direction of the illumination light, the image contains surface information of the biological tissue; when the preset polarization direction is 45-90° to the polarization direction of the illumination light, the image contains deep information of the biological tissue. In practical applications, the preset polarization direction can be set by adjusting the polarization beam splitter according to the target layer.

[0020] Using a polarizing beam splitter has a similar effect to using an analyzer. In addition, a polarizing beam splitter can obtain two separated polarized beams at once, realizing dual-polarization imaging.

[0021] In some embodiments, the number of polarizing beam splitters is N, where N≥2. The reflected or scattered light is sequentially separated by the N polarizing beam splitters to obtain N+1 beams of polarized light with different preset polarization directions, and then passed through N+1 photosensitive elements to obtain N+1 images.

[0022] By using multiple polarizing beam splitters, polarized light with multiple polarization directions can be obtained as needed, thereby obtaining multiple images containing information about biological tissues at different levels.

[0023] A third aspect of the present invention provides an endoscope system comprising the polarized illumination system and the polarized imaging system described above, wherein the polarized illumination system illuminates biological tissue with polarized light, and the polarized imaging system receives light reflected or scattered by the biological tissue and obtains an image.

[0024] By illuminating biological tissue with polarized light and then using a polarization imaging system to obtain polarization-enhanced images of the mucosal surface or deep layers, one can obtain information about a single mucosal surface or deep layer. Using illumination and imaging systems with two or more polarization directions allows for the acquisition of more comprehensive information about tissue lesions.

[0025] In some embodiments, the polarization illumination system comprises two systems, one providing X-polarized light and the other providing Y-polarized light; the polarization imaging system obtains photosensitive images of the X-polarized light and the Y-polarized light. Combining the X- and Y-polarized imaging images allows doctors to achieve visual effects consistent with ordinary light imaging.

[0026] In some embodiments, the endoscopic system can be used for vascular imaging, wherein its polarization illumination system includes a violet laser and a red laser, and the polarization direction of the violet light emitted by the violet laser is one of the X and Y directions, and the polarization direction of the red light emitted by the red laser is the other of the X and Y directions, and the polarization-maintaining fiber in the polarization illumination system is a double polarization-maintaining fiber; the polarization imaging system includes an X-direction analyzer.

[0027] This application can also be used in vascular endoscopy to detect vascular diseases through vascular imaging. During vascular endoscopic imaging, the images of blood vessels are generally not clear due to the presence of blood. By utilizing the characteristic that blood scatters light much less than the vessel wall and the polarization characteristics of scattered light, and using unidirectional polarized light for illumination, the polarization direction of the scattered light from blood is still close to that of the illumination light due to the weak scattering performance of blood. If a polarization imaging device perpendicular to the illumination light direction is used for vascular imaging, the influence of blood on the vessel wall imaging can be eliminated, thereby revealing vascular lesions more clearly.

[0028] In some embodiments, the endoscope system further includes an image processing system for fusing images obtained from the polarization imaging system. By fusing multiple polarization images using the image processing system, an image containing both surface and deep mucosal information can be obtained.

[0029] In addition to the beneficial effects already mentioned above, the present invention also has at least one of the following beneficial effects:

[0030] 1. This invention utilizes polarization characteristics to separate information such as superficial mucosal structure, blood vessels, and color from information such as deep mucosal structure, blood vessels, and color, enabling independent imaging. Compared with existing non-polarized illumination techniques, this invention reduces interference from deep mucosal information when highlighting superficial mucosal information, and vice versa.

[0031] 2. In certain specific situations, polarized illumination combined with polarized imaging is significantly superior to existing illumination and imaging technologies. For example, some cancerous lesions require the detection of differentiation of capillaries on the surface of the mucosa; during surgical bleeding, doctors need to locate deep bleeding points in a timely manner; when detecting gastrointestinal ischemia, it is necessary to rely on the scattering spectrum information of the mucosa to calculate blood oxygen saturation. The specular reflection information of the mucosal surface is considered noise for detection, while this application can eliminate noise, making the calculation of blood oxygen saturation more accurate; in the presence of blood or turbid water during surgery, this application can achieve clear imaging of tissues, facilitating the operation. Attached Figure Description

[0032] To more clearly illustrate the technical solutions and advantages in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of a polarized illumination system provided in Embodiment 1 of the present invention.

[0034] Figure 2 This is a schematic diagram of the first polarized illumination system provided in Embodiment 2 of the present invention.

[0035] Figure 3 This is a schematic diagram of a second polarization illumination system provided in Embodiment 2 of the present invention.

[0036] Figure 4 This is a schematic diagram of the third polarization illumination system provided in Embodiment 2 of the present invention.

[0037] Figure 5 This is a schematic diagram of a polarized illumination system provided in Embodiment 3 of the present invention.

[0038] Figure 6 This is a schematic diagram of a polarization imaging system provided in Embodiment 4 of the present invention.

[0039] Figure 7 This is a schematic diagram of the principle of an endoscope system provided by the present invention.

[0040] Figure 8 This is a schematic diagram of a polarization imaging system provided by the present invention.

[0041] Figure 9 This is a schematic diagram of a polarization analyzer in a polarization imaging system provided in Embodiment 5 of the present invention.

[0042] Figure 10 This is a schematic diagram of a polarization imaging system provided in Embodiment Six of the present invention.

[0043] Figure 11 This is a schematic diagram of another endoscope system provided by the present invention.

[0044] Figure 12 This is a schematic diagram of a polarization imaging system provided in Embodiment 7 of the present invention.

[0045] Figure 13 This is a schematic diagram of another endoscope system provided by the present invention.

[0046] Figure 14 This is a schematic diagram of an endoscope system provided in Embodiment 8 of the present invention.

[0047] Figure 15 This is a schematic diagram of a polarized illumination system in an endoscope system provided in Embodiment 8 of the present invention.

[0048] Figure 16 This is a schematic diagram of a polarized illumination system in an endoscope system provided in Embodiment 9 of the present invention. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages disclosed in the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The embodiments in this application are only used to explain this application and are not intended to limit the scope of protection of this application. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0050] It should be noted that, in the description of the embodiments of this application, "an embodiment" or "embodiment" refers to a specific feature, structure, or characteristic that may be included in at least one implementation of this application. In the description of the embodiments, unless otherwise stated, "a plurality of" means two or more. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.

[0051] In the embodiments of this application, unless otherwise specified, the X direction and the Y direction are perpendicular to each other.

[0052] Example 1

[0053] Example 1 provides a polarization illumination system, including a laser, a lens, and a polarization-maintaining fiber. The laser can be single or multiple, used to provide linearly polarized light. When there is a single laser, the emitted light passes through the lens and enters the polarization-maintaining fiber. When there are multiple lasers, the polarization illumination system also includes a dichroic mirror.

[0054] like Figure 1 As shown, as an example, the laser includes a violet laser 11, a blue laser 12, a green laser 13, and a red laser 14. The emitted light from each laser is coupled through a dichroic mirror 20 and a lens 30 before entering a polarization-maintaining fiber 40.

[0055] Specifically, with Figure 1 Taking a specific perspective, the emitted light from the violet laser 11 is transmitted horizontally through the three-sided dichroic mirror 20. The emitted light from the blue laser 12, green laser 13, and red laser 14 are parallel and vertically incident on the three-sided dichroic mirror 20, where they are reflected. After transmission or reflection, the emitted light from the four lasers is coupled horizontally through the lens 30 and finally enters the polarization-maintaining fiber. This embodiment exemplifies that the emitted light from the laser is set at a 45° angle to the dichroic mirror 20. However, it is understood that the angle between the emitted light from the laser and the dichroic mirror 20 can be arbitrary, as long as the different light rays after transmission and reflection are on the same optical path.

[0056] The polarization illumination system provided in Embodiment 1 is used to achieve single-polarization direction illumination. The laser's output light is linearly polarized. After being coupled into the polarization-maintaining fiber 40 by a dichroic mirror 20 and a lens 30, the polarization-maintaining fiber 40 has polarization-maintaining characteristics, ensuring that the final output light is also linearly polarized. In this embodiment, the polarization-maintaining fiber 40 can be a single-polarization-maintaining fiber.

[0057] Example 2

[0058] Example 2 provides another polarized illumination system, which is consistent with... Figure 1 The difference in the first embodiment shown is that it also includes a polarization controller 50.

[0059] like Figure 2 As shown, as an example, a polarization controller 50 is disposed between each laser and its corresponding dichroic mirror 20 to unify the emitted light from each laser into the same polarization direction, such as the X direction or the Y direction.

[0060] like Figure 3 As shown, as an example, the polarization controller 50 can also be positioned between the last dichroic mirror 20 and the lens 30 in the optical path to unify all light rays into the same polarization direction, such as the X or Y direction. In this example, the polarization controller 50 can be an achromatic polarization controller.

[0061] like Figure 4 As shown, as an example, the polarization controller 50 can also be positioned between two polarization-maintaining fiber segments 40 to control the polarization direction of light within the fiber, such as the X or Y direction. In this example, the polarization controller 50 can be an achromatic fiber polarization controller.

[0062] The polarization illumination system provided in Embodiment 2 is used to achieve dual-polarization direction illumination. The polarization controller 50 can control the phase of the laser output light, thereby controlling the polarization direction of the laser. For example, it can change the Y-polarized light to the X-polarized light and then couple it into the polarization-maintaining fiber 40. Thus, the illumination optical path can achieve both X-polarized illumination and Y-polarized illumination, thereby enabling simultaneous detection of deep and shallow mucosal images. In this embodiment, the polarization-maintaining fiber 40 can be a dual-polarization-maintaining fiber, meaning it has polarization-maintaining capability in both the X and Y directions.

[0063] Example 3

[0064] Example 3 provides another polarized illumination system, including a light source, a lens, an illumination fiber, and a polarizer. The light source can be single or multiple, and is not limited to providing linearly polarized light; ordinary light sources other than lasers, such as LEDs, xenon lamps, and SLDs, can also meet the requirements. When there is a single light source, the emitted light passes through the lens into the illumination fiber and is polarized by the polarizer to achieve illumination. When there are multiple light sources, the polarized illumination system also includes a dichroic mirror.

[0065] like Figure 5 As shown, as an example, the light source includes a violet light source 15, a blue light source 16, a green light source 17, and a red light source 18. The emitted light from each light source is coupled through a dichroic mirror 20 and a lens 30 and then enters the illumination fiber 41, and then passes through a polarizer 60 to obtain polarized light.

[0066] The polarization illumination system provided in Embodiment 3 can achieve single-polarization direction illumination or dual-polarization direction illumination using a common light source and a polarizer 60. The polarizer 60 is, for example, a polarizer or a combination of polarizers. A polarizer can convert light into polarized light in one polarization direction; a combination of polarizers can consist of two types of polarizers and can be switched as needed to obtain two types of polarized light with different polarization directions.

[0067] Example 4

[0068] Example 4 provides a polarization imaging system, such as Figure 6 As shown, as an example, it includes an analyzer 70, an imaging lens 80, and a photosensitive device 90. The analyzer 70 only allows light of a certain polarization direction to pass through, while light of other polarization directions is reflected or absorbed. The analyzer 70, imaging lens 80, and photosensitive device 90 are used in combination to achieve imaging of light with a specific polarization direction. This application does not limit the imaging lens 80; it can be any combination of optical lenses.

[0069] See Figure 7 As an example, when a polarized illumination system emits Y-polarized light onto biological tissue, a small portion of the light undergoes specular reflection and a small amount of scattering on the tissue surface. The polarization state of the specularly reflected light remains unchanged, still Y-polarized. This specularly reflected light carries structural information such as various protrusions and depressions on the mucosal surface. If the analyzer is Y-polarized (i.e., the analyzer direction is 0° from the polarization direction of the illumination light), the obtained image is an image of the mucosal surface layer. Most of the light enters the biological tissue and is scattered. The scattered light undergoes depolarization, meaning that the light is no longer simply Y-polarized, and light can also be detected in the X-polarized direction. The deeper the incident light penetrates into the human tissue, the more severe the depolarization phenomenon, and the stronger the detectable X-polarized light. If the analyzer is X-polarized (i.e., the analyzer direction is 90° from the polarization direction of the illumination light), the obtained image is an image that highlights the deep mucosal layer information after multiple scattering and depolarization.

[0070] For ease of understanding, the above only shows whether the polarization direction of the illumination and the analyzer is perpendicular or horizontal. In practical applications, when detecting superficial lesions, the analyzer direction can be at an angle of 0-45° to the polarization direction of the illumination light; when detecting deep lesions, the analyzer direction can be at an angle of 45-90° to the polarization direction of the illumination light. Figure 8As shown, taking the polarization direction of the illumination light as the Y direction as an example, after passing through the polarization imaging system, the tissue surface structure information exists in the polarized light in the Y direction. As the angle between the polarizer direction and the polarization direction of the illumination light gradually increases, the tissue information contained in the polarized light gradually becomes deeper tissue information. For example, in the angle range of 0-45°, the information of the superficial capillaries can be obtained; in the angle range of 45-90°, the information of the next deeper tissue can be obtained; and in the polarized light in the X direction, the information of the deepest tissue can be obtained. That is, by adjusting the polarizer direction according to the target layer, the corresponding tissue information can be obtained.

[0071] Furthermore, by employing two sets of polarization imaging systems provided in Embodiment 4 in the endoscope, and with two sets equipped with polarizers of different polarization directions, the photosensitive device in one set can obtain information about the surface layer of the mucosa, while the photosensitive device in the other set can obtain information about the deep layer of the mucosa. The fusion of the two photosensitive images can yield an image that contains both information about the surface layer of the mucosa and information about the deep layer of the mucosa.

[0072] Furthermore, by employing two or more sets of the polarization imaging systems provided in Embodiment 4 in the endoscope, with each set having a polarization analyzer of a different polarization direction, multiple images containing information about tissues at different levels can be obtained, and the multiple images can be further fused.

[0073] Example 5

[0074] Example 5 provides a polarization imaging system, including an imaging lens and a polarization photosensitive device. The polarization photosensitive device has a separate analyzer (e.g., a polarizer) placed in front of the photosensitive element. Its polarization analysis structure includes X-polarization and Y-polarization directions (e.g., ...). Figure 9 As shown in the figure, such a photosensitive element can obtain images in both the X-polarization direction and the Y-polarization direction. Finally, an image processing system is used to obtain an image that contains both surface and deep mucosal information.

[0075] Example 6

[0076] Example 6 provides a polarization imaging system, such as Figure 10 As shown, as an example, it includes a polarizing beam splitter 71, an imaging lens 80, and a photosensitive device 90. The polarizing beam splitter 71 can separate a beam of light polarized in the X and Y directions, thereby separating deep tissue information from surface tissue information, and imaging is performed separately by two photosensitive devices (see [reference]). Figure 11 Subsequently, depending on the needs, the two images are fused using an image processor to synthesize an image that contains both deep and shallow tissue information.

[0077] Similar to Example 4, for ease of understanding, the above only shows whether the polarization direction of the illumination light is perpendicular or horizontal to the polarization beam splitting direction. In practical applications, the angle between the polarization beam splitting direction and the polarization direction of the illumination light can be adjusted according to the target layer to be detected.

[0078] Example 7

[0079] Example 7 provides a polarization imaging system, such as Figure 12 As shown, the difference between this embodiment and Embodiment 5 is that the polarizing beam splitter 71 first separates the light beam with the same polarization direction as the illumination light to obtain information about the surface structure of the tissue mucosa. The remaining polarized light, containing deep layer information, enters another polarizing beam splitter 71, resulting in two further separated beams that enter two photosensitive devices 90 respectively. One of the two further separated beams has a polarization direction of 0-45° to the illumination light, and the other beam has a polarization direction of 45-90° to the illumination light (see [reference]). Figure 13 This allows us to obtain information about substances such as superficial and deep mucosal blood vessels. By fusing these images containing different information, we can obtain comprehensive information about the tissue.

[0080] Example 8

[0081] Example 8 provides a polarization endoscope system, such as Figure 14 As shown, it includes a polarized illumination system 1 and a polarized imaging system 2. The polarized illumination system 1 illuminates the biological tissue 4 with polarized light, and the polarized imaging system 2 receives the light reflected or scattered by the biological tissue 4.

[0082] like Figure 15 As shown, as an example, the polarized illumination system 1 includes two sets of lasers and polarization controllers, each set of lasers and polarization controllers being connected to... Figure 2 The two lasers have the same layout, with one group providing X-axis polarized light and the other providing Y-axis polarized light. The light emitted from the two lasers and polarization controllers is coupled through polarization combiner 21 and lens 30 and then enters polarization-maintaining fiber 40, which illuminates the biological tissue 4.

[0083] Polarization Imaging System 2 and Figure 9 The layout is the same as that in Example 5, which is the polarization imaging system. In this system, two photosensitive devices image simultaneously and the two images are fused to obtain ordinary light imaging.

[0084] The polarization endoscope system provided in this embodiment adopts a dual-polarization illumination system and a dual-polarization imaging system, which enables the final image to be obtained with pure white light. The visual effect is consistent with the existing ordinary imaging effect and is more in line with the doctor's habits.

[0085] Example 9

[0086] Example 9 provides a polarization endoscope system for vascular imaging, including a polarization illumination system and a polarization imaging system, wherein the polarization illumination system (see...) Figure 16 The system includes a violet laser 11 and a red laser 14. The polarization direction of the lasers is controlled by a polarization controller 50. The polarization direction of the violet light is the X-direction, and the polarization direction of the red light is the Y-direction. The two beams pass through a dichroic mirror 20 and a lens 30 before entering a polarization-maintaining fiber 40. The polarization-maintaining fiber 40 in the polarization illumination system is a double polarization-maintaining fiber 40. The polarization imaging system can be... Figure 6 The polarization imaging system shown in the figure has an analyzer 70 that is an X-direction analyzer.

[0087] This embodiment utilizes the characteristics of violet light having a shallow penetration depth, red light having a deep penetration depth, and blood vessels having a high absorption of violet light to directly obtain a clear image containing both superficial and deep blood vessels without the need for image fusion.

[0088] Example 10

[0089] Example 10 provides an image processing system suitable for a dual-polarization illumination system. The dual-polarization illumination system can alternately provide X-polarized light and Y-polarized light. The polarization imaging system is determined to be either X-polarization imaging or Y-polarization imaging as needed. The image processing system then alternately acquires X-polarized and Y-polarized illumination images. Specifically, the first frame is acquired under X-polarized illumination, the second under Y-polarized illumination, the third under X-polarized illumination, the fourth under Y-polarized illumination, and so on. This allows the first frame to be an image of the mucosal surface and the second to be an image of the mucosal depth. Using an image processing device, the first and second frames are fused to form a comprehensive image containing both mucosal surface and deep information.

[0090] Example 11

[0091] Example 11 provides an image processing system applicable to the polarization imaging system in Examples 5 and 6. The polarization imaging system includes a polarization beam splitter and at least two photosensitive devices. The image processing system acquires images from the photosensitive devices and fuses them into a comprehensive image that contains both surface and deep mucosal information.

[0092] This embodiment can be applied to both dual-polarization lighting systems and single-polarization lighting systems.

[0093] It should be noted that the order of the embodiments described above is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. Furthermore, specific embodiments have been described above. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps described in the claims can be performed in a different order than that shown in the embodiments and still achieve the desired result. Additionally, the processes depicted in the drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0094] The same or similar parts between the various embodiments in this specification can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments.

[0095] The above description is only a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A polarized illumination system for providing illumination light to biological tissues, characterized in that, It includes at least one laser, a lens, and a polarization-maintaining fiber; the polarized light emitted from the laser is coupled by the lens and enters the polarization-maintaining fiber, and the illumination light is emitted from the polarization-maintaining fiber.

2. The polarized illumination system according to claim 1, characterized in that, It also includes at least one polarization controller, which is disposed at at least one of the following locations: between the laser and the lens, between the lens and the polarization-maintaining fiber, in the polarization-maintaining fiber, and after the polarization-maintaining fiber.

3. The polarized illumination system according to claim 2, characterized in that, The polarization-maintaining fiber is a double polarization-maintaining fiber.

4. The polarized illumination system according to claim 1, characterized in that, The laser is replaced by one of LED, xenon lamp, or SLD light source, and the polarization-maintaining fiber is replaced by a non-polarization-maintaining fiber. The polarization illumination system also includes a polarizer, which is located after the non-polarization-maintaining fiber. The emitted light from the LED or xenon lamp is coupled into the non-polarization-maintaining fiber through the lens and then converted into polarized light by the polarizer.

5. A polarization imaging system for receiving light reflected or scattered by biological tissue after it has been illuminated by lighting, characterized in that, The system includes an analyzer, an imaging lens, and a photosensitive device. The reflected or scattered light passes through the analyzer to obtain polarized light with the same polarization direction as the analyzer, and then passes through the imaging lens to enter the photosensitive device to obtain an image. Alternatively, the analyzer can be placed in front of the photosensitive device to form a polarization photosensitive device, and the reflected or scattered light enters the polarization photosensitive device through the imaging lens to obtain an image.

6. The polarization imaging system according to claim 5, characterized in that, When the polarization direction is at an angle of 0-45° to the polarization direction of the illumination light, the image contains surface information of the biological tissue; when the polarization direction is at an angle of 45-90° to the polarization direction of the illumination light, the image contains deep information of the biological tissue.

7. A polarization imaging system for receiving light reflected or scattered by biological tissue after being illuminated by lighting, characterized in that, The device includes an imaging lens, a polarizing beam splitter, and a photosensitive device. The reflected or scattered light passes through the imaging lens and is then separated by the polarizing beam splitter to obtain polarized light with a preset polarization direction. The polarized light with the preset polarization direction enters the photosensitive device to obtain an image.

8. The polarization imaging system according to claim 7, characterized in that, When the preset polarization direction is at an angle of 0-45° to the polarization direction of the illumination light, the image contains surface information of the biological tissue; when the preset polarization direction is at an angle of 45-90° to the polarization direction of the illumination light, the image contains deep information of the biological tissue.

9. The polarization imaging system according to claim 7, characterized in that, The number of polarizing beam splitters is N, where N≥2. The reflected or scattered light is sequentially separated by the N polarizing beam splitters to obtain N+1 beams of polarized light with different preset polarization directions, and then passed through the N+1 photosensitive elements to obtain N+1 images.

10. An endoscope system, characterized in that, The system includes a polarized illumination system according to any one of claims 1-4 and a polarized imaging system according to any one of claims 5-9, wherein the polarized illumination system illuminates biological tissue with polarized light, and the polarized imaging system receives light reflected or scattered by the biological tissue and obtains an image.

11. The endoscope system according to claim 10, characterized in that, The polarization illumination system consists of two parts, one providing X-axis polarized light and the other providing Y-axis polarized light; the polarization imaging system obtains photosensitive images of X-axis polarized light and Y-axis polarized light.

12. The endoscopic system according to claim 10, for vascular imaging, characterized in that, The polarization illumination system includes a violet laser and a red laser, wherein the polarization direction of the violet light emitted by the violet laser is one of the X and Y directions, and the polarization direction of the red light emitted by the red laser is the other of the X and Y directions. The polarization-maintaining fiber in the polarization illumination system is a double polarization-maintaining fiber. The polarization imaging system includes an X-direction analyzer.

13. The endoscope system according to claim 10, characterized in that, It also includes an image processing system for fusing the images obtained by the polarization imaging system.

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