Method, medium and device for detecting autofluorescence intensity of optical fiber bundle

Abstract

The invention relates to the field of optical fiber detection, and discloses an optical fiber bundle autofluorescence intensity detection method, medium and device, and the method comprises the steps: obtaining an end face image of a to-be-detected optical fiber bundle, extracting connected domains of the to-be-detected optical fiber bundle, and generating a defect judgment result of each connected domain; acquiring an end face image of the to-be-detected optical fiber bundle under each illuminance level; extracting a brightness value of a non-defective target connected domain in each end face image, and screening out a target brightness mean value under each illuminance level according to a preset condition; and associating each target brightness mean value with the corresponding optical power, and fitting to generate a curve that the autofluorescence brightness changes along with the optical power. The method is accurate in detection result, can adapt to optical fiber bundles with different lengths and different transmittances, can select a fluorescent contrast agent in a proper concentration range according to the detection result, reduces the interference of background noise on a fluorescent signal corresponding to the fluorescent contrast agent, and further improves the accuracy of a diagnosis result.

Description

Technical Field

[0001] The present invention relates to the field of optical fiber detection, and in particular to a method, medium and device for detecting the spontaneous fluorescence intensity of an optical fiber bundle. Background Art

[0002] In systems such as probe-based confocal microendoscopes, the imaging fiber bundle is an essential component, transmitting excitation light energy, fluorescence signals, and scanning position. Typically composed of glass or optical plastic, the imaging fiber bundle exhibits autofluorescence for light within a certain wavelength range. After incident light is focused at one end of the bundle and enters a single optical fiber, the optical energy density within the fiber is very high due to its thin diameter, stimulating strong autofluorescence.

[0003] When imaging fluorescent contrast agents during the use of a confocal microendoscope, the autofluorescence of the imaging fiber bundle will always be present and superimposed on the fluorescence signal generated by the fluorescent contrast agent. In this way, autofluorescence becomes a kind of background noise. When the concentration of the fluorescent contrast agent is low, it will significantly deteriorate the signal-to-noise ratio of the imaging, affecting the interpretation of the image and clinical diagnosis. Therefore, testing and characterizing the autofluorescence intensity of the imaging fiber bundle is a technical problem that needs to be solved. Existing technologies usually use post-processing algorithms to reduce the autofluorescence noise in fluorescent contrast agent imaging. Even if the impact on imaging is reduced, it is still impossible to test the autofluorescence intensity of the imaging fiber bundle, nor can it improve the sensitivity of detection. Summary of the Invention

[0004] The present invention provides a method, a medium and a device for detecting the spontaneous fluorescence intensity of an optical fiber bundle, which solve the above-mentioned technical problems.

[0005] A first aspect of an embodiment of the present invention provides a method for detecting the autofluorescence intensity of an optical fiber bundle, comprising the following steps:

[0006] Step 1: Acquire an end face image of the optical fiber bundle to be inspected, extract connected domains of the end face image, and generate defect determination results for each connected domain;

[0007] Step 2: configure the first light source with multiple illumination levels of increasing illumination, and collect the end face image of the optical fiber bundle to be detected at each illumination level, which is recorded as S n , n=1, 2, ..., N, where N is the number of illumination levels; the first light source is a laser, and the light source light of the first light source is injected from the proximal end of the optical fiber bundle to be detected;

[0008] Step 3: Obtain the target connected domain information of the non-defective state in the defect judgment result, and extract the end face image S corresponding to each illumination level n The brightness values of all target connected domains in Where M is the number of target connected domains;

[0009] Step 4: Calculate the average brightness aVS of all target connected domains at each illumination level n , and screen out multiple target brightness means according to preset conditions;

[0010] Step 5: Associate each target brightness mean with the corresponding optical power to establish an association set, and fit the data of the association set using a preset method to generate a curve of the spontaneous fluorescence brightness corresponding to the optical fiber bundle to be detected versus optical power.

[0011] A second aspect of the embodiments of the present invention provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, the above-mentioned method for detecting the spontaneous fluorescence intensity of an optical fiber bundle is implemented.

[0012] A third aspect of an embodiment of the present invention provides a device for detecting the autofluorescence intensity of an optical fiber bundle, comprising a first light source, a second light source, a clamping assembly for clamping the optical fiber bundle to be detected, a lens group, a dichroic mirror, an image acquisition unit, and an image processing unit.

[0013] The second light source is arranged at the far end of the optical fiber bundle to be detected. The light of the second light source enters from the far end of the optical fiber bundle to be detected, exits from the near end, is focused by the lens group, and transmits through the dichroic mirror;

[0014] The first light source is arranged above the dichroic mirror, and the light from the first light source is reflected by the dichroic mirror and focused by the lens group before entering the proximal end of the optical fiber bundle to be detected;

[0015] The image acquisition unit is used to acquire a first end face image of the optical fiber bundle to be detected when the first light source is turned on and a second end face image of the optical fiber bundle to be detected when the second light source is turned on;

[0016] The image processing unit is used to execute the above-mentioned spontaneous fluorescence intensity detection method.

[0017] The beneficial effects of the present invention are as follows: the present invention provides a method, medium and device for detecting the spontaneous fluorescence intensity of an optical fiber bundle, which divides the connected domain of the end face image of the optical fiber bundle into a defect state and a non-defect state, and selects the brightness value of the connected domain in the non-defect state to establish a curve of the spontaneous fluorescence intensity of the optical fiber bundle as a inverse of the optical power. Not only is the detection result accurate and can adapt to optical fiber bundles of different lengths and different transmittances, but also a fluorescent contrast agent in a suitable concentration range can be selected according to the detection results, thereby reducing the interference of background noise on the corresponding fluorescent signal of the fluorescent contrast agent, and further improving the accuracy of the detection result.

[0018] In order to make the above-mentioned objects, features and advantages of the invention more obvious and easy to understand, preferred embodiments of the present invention are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 1 is a schematic flow chart of the method for detecting the autofluorescence intensity of an optical fiber bundle provided in Example 1;

[0021] Figure 2 2 is a schematic structural diagram of the device for detecting the spontaneous fluorescence intensity of an optical fiber bundle provided in Example 2;

[0022] Figure 3 3 is a schematic structural diagram of the image processing unit in the device for detecting the spontaneous fluorescence intensity of an optical fiber bundle provided in Example 3. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is 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 intended to limit the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0024] It should be noted that, unless there is a conflict, the various features of the embodiments of the present invention may be combined with each other and are all within the scope of protection of the present invention. In addition, although the functional modules are divided in the device schematics and the logical order is shown in the flow charts, in some cases, the steps shown or described may be performed in a different order than the module division in the device or the order in the flow charts. Furthermore, the terms "first," "second," "third," etc. used in the present invention do not limit the data or execution order, but only distinguish between identical or similar items with substantially the same functions and effects.

[0025] Figure 1 FIG. 1 is a flow chart of a method for detecting the spontaneous fluorescence intensity of an optical fiber bundle provided in Example 1. Figure 1 As shown, the following steps are included:

[0026] Step 1: Acquire an end face image of the optical fiber bundle to be inspected, extract connected domains of the end face image, and generate defect determination results for each connected domain;

[0027] Step 2: configure the first light source with multiple illumination levels of increasing illumination, and collect the end face image of the optical fiber bundle to be detected at each illumination level, which is recorded as S n , n=1, 2, ..., N, where N is the number of illumination levels; the first light source is a laser, and the light source light of the first light source is injected from the proximal end of the optical fiber bundle to be detected;

[0028] Step 3: Obtain the target connected domain information of the non-defective state in the defect judgment result, and extract the end face image S corresponding to each illumination level n The brightness values of all target connected domains in Where M is the number of target connected domains;

[0029] Step 4: Calculate the average brightness aVS of all target connected domains at each illumination level n , and screen out multiple target brightness means according to preset conditions;

[0030] Step 5: Associate each target brightness mean with the corresponding optical power to establish an association set, and fit the data of the association set using a preset method to generate a curve of the spontaneous fluorescence brightness corresponding to the optical fiber bundle to be detected versus optical power.

[0031] The above embodiment provides a method for detecting the spontaneous fluorescence intensity of an optical fiber bundle. The method divides the connected domain of the optical fiber bundle end face image into a defect state and a non-defect state, and selects the brightness value of the connected domain in the non-defect state to establish a curve of the spontaneous fluorescence intensity of the optical fiber bundle as a function of optical power. Not only is the detection result accurate, but a fluorescent contrast agent within a suitable concentration range can also be selected based on the detection results, thereby reducing the interference of background noise on the fluorescent signal corresponding to the fluorescent contrast agent, and further improving the accuracy of the detection results.

[0032] Each step of the above method is described in detail below using specific embodiments.

[0033] Specifically, the connected domains in the embodiments of the present invention are regions formed by adjacent pixels, each representing a fiber in the fiber bundle. By identifying connected domains, isolated noise points or non-target areas can be effectively eliminated, focusing on the area most likely to be the fiber core. For example, in one embodiment, the end-face image can be preprocessed by binarization, and then the connected domains of the binarized image can be extracted. Features such as area, shape, and edge smoothness of the connected domains are extracted and then compared with preset defect standards to determine various defects on the fiber bundle end face. For example, a connected domain with an excessively small area may be dust, an irregular shape may be a scratch, and so on.

[0034] For example, in a preferred embodiment, the defect determination result of each connected domain is generated in step 1, specifically:

[0035] S101, capturing an end-face image of the end face of the optical fiber bundle to be inspected after being focused by a lens assembly, the end-face image comprising a first end-face image corresponding to a first light source and a second end-face image corresponding to a second light source. Here, the first light source is a laser, and light from the first light source is incident from the proximal end of the optical fiber bundle to be inspected, and the second light source is an LED parallel surface light source, and light from the second light source is incident from the distal end of the optical fiber bundle to be inspected.

[0036] S102, extracting a first brightness value of each connected domain in the first end face image and a second brightness value of the corresponding connected domain in the second end face image, wherein the first brightness value is recorded as The second brightness value is recorded as Wherein K represents the number of connected domains corresponding to the optical fiber bundle to be detected;

[0037] S103: Calculate the second brightness value of each connected region With the first brightness value The brightness ratio of k , k=1,2,…,K;

[0038] S104, for {r k ,k=1,2,…,K} is fitted according to Gaussian distribution to generate Gaussian function parameters u1 and σ1;

[0039] S105, when the brightness ratio r of any connected domain k ≥u1-3σ1, the connected domain is determined to be in a non-defective state; otherwise, the connected domain is determined to be in a defective state.

[0040] The above preferred embodiment calculates the brightness ratio and utilizes Gaussian distribution fitting. Gaussian distribution fitting can provide statistical characteristics about the distribution of brightness ratio, reduce misjudgment caused by factors such as ambient light changes and image noise, thereby more accurately identifying defects on the optical fiber end face and improving detection efficiency and detection accuracy.

[0041] Exemplarily, in step 2, a detection level is generated based on the target detection accuracy and / or target detection efficiency, and the number of illumination levels of the first light source and / or the second light source is generated based on the detection level, so as to adapt to different ambient brightness and ensure the clarity of the captured end face image and the accuracy of the constructed curve.

[0042] In step 4 of a preferred embodiment, the preset condition is: the average brightness value aVS corresponding to the nth illumination leveln Not greater than 0.9*T, where T is the maximum brightness value of the image acquisition unit that generates the end face image. The image acquisition unit here is a photoelectric conversion module. In specific scenarios, a CCD camera, a CMOS camera, or the like can be used. The upper limit of brightness varies depending on the specific structure and design parameters, and can be denoted as T. To ensure the quality of curve fitting in subsequent steps, it is necessary to ensure the number of target brightness mean values screened in this step, i.e., the amount of data in the associated set. Therefore, in a preferred embodiment, step 4 further includes:

[0043] Setting a first weight for the initial data of the association set;

[0044] When the number of brightness averages that meet the preset condition is less than the preset threshold, the preset condition is adjusted to aVS n After the value is no greater than 0.95*T, perform data screening again;

[0045] A second weight is set for the newly added data of the association set according to the screening result, where the second weight is smaller than the first weight, so as to perform curve fitting based on the updated association set to further improve the fitting result.

[0046] In a specific embodiment, in step 5, the data of the association set are fitted using the least squares method or the total least squares method. The least squares method finds the best function match for the data by minimizing the sum of squares of the errors. In curve fitting, it can be used to solve the parameters of linear or nonlinear models and predict the data. The total least squares method (TLS) is an extension of the least squares method. It takes into account the errors in the model and the observed data, and finds the best fit by minimizing the sum of squares of the errors of the residual vector and the design matrix. It works better when there are outliers or large noise in the processing data.

[0047] Exemplarily, a preferred embodiment of the method for detecting the intensity of spontaneous fluorescence also includes the following steps: querying the curve of the spontaneous fluorescence brightness of the optical fiber bundle to be detected as a function of optical power, obtaining the predicted spontaneous fluorescence brightness of the optical fiber bundle to be detected under the current optical power, and generating a target concentration range of the fluorescent contrast agent based on the predicted spontaneous fluorescence brightness, so that when using a confocal microendoscope for disease diagnosis, a fluorescent contrast agent of a suitable concentration can be selected to reduce the interference of background noise on the fluorescent signal corresponding to the fluorescent contrast agent, thereby further improving the accuracy of the detection results.

[0048] Exemplarily, step 1 of a preferred embodiment further includes a step of adjusting the position of the optical fiber bundle to be detected, so as to adjust the end face of the optical fiber bundle to be detected to an optimal position relative to the lens assembly, specifically:

[0049] S001, configuring a plurality of preset positions for the optical fiber bundle to be tested, with the distances from the optical fiber bundle to the lens group increasing in sequence;

[0050] S002, after moving the optical fiber bundle to be inspected to a middle position, adjusting the illumination of the first light source to an optimal illumination, collecting a first end face image of the optical fiber bundle to be inspected, and calculating the focus;

[0051] S003, keep the current illumination of the first light source unchanged, move the optical fiber bundle to be detected to the next preset position, collect the first end face image again and calculate the focus, and judge whether the change amplitude of the focus between two adjacent times is less than the preset amplitude threshold. If so, the current position is the optimal position. If not, adjust the current position of the optical fiber bundle to be detected according to the judgment result, and repeat S003.

[0052] Specifically, focus can be defined as one or more of the image's gradient mean, gradient sum, variance, and standard deviation. By adjusting the fiber bundle end face to the optimal position and optimal light brightness, the best image to be detected can be obtained, thereby improving detection accuracy.

[0053] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0054] An embodiment of the present invention further provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, the above-mentioned method for detecting the spontaneous fluorescence intensity of an optical fiber bundle is implemented.

[0055] Figure 2 Schematic diagram of the structure of the spontaneous fluorescence intensity detection device of the optical fiber bundle provided in Example 2, as shown in FIG. Figure 2 As shown, it includes a first light source 1, a second light source 3, a clamping assembly for clamping the optical fiber bundle 15 to be detected, a lens group 7, a dichroic mirror 6, an image acquisition unit 5 and an image processing unit 4.

[0056] The second light source 3 is disposed at the distal end of the optical fiber bundle 15 to be detected. Light from the second light source 3 enters from the distal end of the optical fiber bundle 15 to be detected, exits from the proximal end, is focused by the lens group 7, and is transmitted through the dichroic mirror 6.

[0057] The first light source 1 is arranged above the dichroic mirror 6. The light from the first light source 1 is reflected by the dichroic mirror 6 and focused by the lens group 7 before entering the proximal end of the optical fiber bundle 15 to be detected.

[0058] The image acquisition unit 5 is used to acquire a first end surface image of the optical fiber bundle 15 to be detected when the first light source 1 is turned on and a second end surface image of the optical fiber bundle 15 to be detected when the second light source 3 is turned on;

[0059] The image processing unit 4 is used to execute the above-mentioned method for detecting the intensity of the spontaneous fluorescence.

[0060] The above embodiment provides a device for detecting the spontaneous fluorescence intensity of an optical fiber bundle. Not only is the detection result accurate and adaptable to optical fiber bundles of different lengths and different transmittances, but also a fluorescent contrast agent within a suitable concentration range can be selected based on the detection results, thereby reducing the interference of background noise on the fluorescent signal corresponding to the fluorescent contrast agent and further improving the accuracy of the diagnostic results.

[0061] Exemplarily, the clamping assembly includes a proximal clamping device 8 for clamping one end of the optical fiber bundle 15 to be detected close to the lens assembly 7 and a distal clamping device 12 for clamping the other end of the optical fiber bundle 15 to be detected.

[0062] In a preferred embodiment, the spontaneous fluorescence intensity detection device further includes a movement controller 9 connected to the clamping assembly, and the movement controller 9 is used to move the clamping assembly axially so that the end face of the optical fiber bundle 15 to be detected is close to or away from the lens group 7.

[0063] Exemplarily, the lens assembly 7 can be a collection of two or more lenses, such as a first lens element, a second lens element, a third lens element, and a fourth lens element, wherein the first lens element is a plano-convex lens, the second lens element is a doublet, the third lens element is an aspheric lens, and the fourth lens element is a biconvex lens. This lens assembly can focus light passing through the optical fiber bundle, thereby ensuring a clearer captured image and enabling accurate identification of defects on the end face of the optical fiber bundle.

[0064] Figure 3 FIG. 4 is a schematic diagram of the structure of the image processing unit 4 in one embodiment. Figure 3 Shown, including:

[0065] The defect determination unit 100 is configured to obtain an end face image of the optical fiber bundle to be inspected, extract connected domains of the end face image, and generate a defect determination result for each connected domain;

[0066] The image acquisition unit 200 is used to configure a plurality of illumination levels with increasing illumination for the first light source, and respectively acquire an end face image of the optical fiber bundle to be detected at each illumination level, which is denoted as S n , n=1, 2, ..., N, where N is the number of illumination levels; the first light source is a laser, and the light source light of the first light source is injected from the proximal end of the optical fiber bundle to be detected;

[0067] The first calculation unit 300 is used to obtain the target connected domain information of the non-defective state in the defect judgment result, and extract the end face image S corresponding to each illumination level. n The brightness values of all target connected domains in Where M is the number of target connected domains;

[0068] The second calculation unit 400 is used to calculate the brightness mean aVS of all target connected areas at each illumination level. n , and screen out multiple target brightness means according to preset conditions;

[0069] The curve fitting unit 500 is used to associate each target brightness mean with the corresponding optical power, establish an association set, and fit the data of the association set using a preset method to generate a curve of the spontaneous fluorescence brightness corresponding to the optical fiber bundle to be detected versus optical power.

[0070] In a preferred embodiment, a query unit is further included, which is used to query the curve of the spontaneous fluorescence brightness of the optical fiber bundle to be detected as inversely proportional to the optical power, obtain the predicted spontaneous fluorescence brightness of the optical fiber bundle to be detected under the current optical power, and generate a target concentration range of the fluorescent contrast agent based on the predicted spontaneous fluorescence brightness.

[0071] In a preferred embodiment, the defect determination unit 100 specifically includes:

[0072] an acquisition unit, configured to acquire an end face image of the end face of the optical fiber bundle to be detected after being focused by the lens group, the end face image comprising a first end face image corresponding to a first light source and a second end face image corresponding to a second light source, wherein the second light source is an LED parallel surface light source, and its light source light is emitted from the distal end of the optical fiber bundle to be detected;

[0073] A brightness extraction unit is configured to extract a first brightness value of each connected domain in the first end face image and a second brightness value of the corresponding connected domain in the second end face image, wherein the first brightness value is recorded as The second brightness value is recorded as Wherein K represents the number of connected domains corresponding to the optical fiber bundle to be detected;

[0074] A ratio calculation unit, configured to calculate the second brightness value of each connected domain With the first brightness value The brightness ratio of k , k=1,2,…,K;

[0075] Parameter generation unit, used to k ,k=1,2,…,K} is fitted according to Gaussian distribution to generate Gaussian function parameters u1 and σ1;

[0076] The judgment unit is used to determine the brightness ratio r of any connected domain. k ≥u1-3σ1, the connected domain is determined to be in a non-defective state; otherwise, the connected domain is determined to be in a defective state.

[0077] It should be noted that the above explanation of the embodiment of the method for detecting the spontaneous fluorescence intensity of an optical fiber bundle is also applicable to the apparatus for detecting the spontaneous fluorescence intensity of an optical fiber bundle in the above embodiment, and will not be repeated here.

[0078] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0079] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0080] Those skilled in the art will appreciate that the units and method steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present invention.

[0081] In the embodiments provided by the present invention, it should be understood that the disclosed devices / terminal equipment and methods can be implemented in other ways. For example, the device / terminal equipment embodiments described above are merely illustrative. For example, the division of the modules or units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0082] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0083] In addition, the functional units in the various embodiments of the present invention may be integrated into a single processing unit, each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0084] The present invention is not limited to what is described in the specification and embodiments, and additional advantages and modifications will be readily apparent to those skilled in the art. Therefore, the present invention is not limited to the specific details, representative devices, and illustrative examples shown and described herein without departing from the spirit and scope of the general concept defined by the claims and their equivalents.

Claims

1. A method for detecting the spontaneous fluorescence intensity of an optical fiber bundle, characterized in that: The following steps are involved: Step 1: Acquire an end face image of the optical fiber bundle to be inspected, extract connected domains of the end face image, and generate defect determination results for each connected domain; Step 2: configure the first light source with multiple illumination levels of increasing illumination, and collect the end face image of the optical fiber bundle to be detected at each illumination level, which is recorded as S n , n=1, 2, ..., N, where N is the number of illumination levels; the first light source is a laser, and the light source light of the first light source is injected from the proximal end of the optical fiber bundle to be detected; Step 3: Obtain the target connected domain information of the non-defective state in the defect judgment result, and extract the end face image S corresponding to each illumination level n The brightness values of all target connected domains in Where M is the number of target connected domains; Step 4: Calculate the average brightness aVS of all target connected domains at each illumination level n , and screen out multiple target brightness means according to preset conditions; Step 5: Associate each target brightness mean with the corresponding optical power to establish an association set, and fit the data of the association set using a preset method to generate a curve of the spontaneous fluorescence brightness corresponding to the optical fiber bundle to be detected versus optical power.

2. The method for detecting the spontaneous fluorescence intensity of an optical fiber bundle according to claim 1, wherein: In step 5, the data of the association set are fitted using the least square method or the total least square method.

3. The method for detecting the spontaneous fluorescence intensity of an optical fiber bundle according to claim 1, wherein: In step 4, the preset condition is: the average brightness value aVS corresponding to the nth illumination level n Not greater than 0.9*T, where T is the maximum brightness value of the image acquisition unit that generates the end face image.

4. The method for detecting the spontaneous fluorescence intensity of an optical fiber bundle according to claim 2, wherein: The step 4 further comprises: Setting a first weight for the initial data of the association set; When the number of brightness averages that meet the preset condition is less than the preset threshold, the preset condition is adjusted to aVS n After the value is no greater than 0.95*T, perform data screening again; A second weight is set for the newly added data of the association set according to the screening result, where the second weight is smaller than the first weight, so as to perform curve fitting based on the updated association set.

5. The method for detecting the spontaneous fluorescence intensity of an optical fiber bundle according to claim 1, wherein: In step 2, a detection level is generated according to the target detection accuracy and / or the target detection efficiency, and the number of illumination levels is generated according to the detection level.

6. The method for detecting the spontaneous fluorescence intensity of an optical fiber bundle according to claim 1, wherein: The following steps are also included: A curve showing the variation of the autofluorescence brightness of the optical fiber bundle to be detected with the optical power is queried to obtain the predicted autofluorescence brightness of the optical fiber bundle to be detected under the current optical power, and a target concentration range of the fluorescent contrast agent is generated according to the predicted autofluorescence brightness.

7. The method for detecting the spontaneous fluorescence intensity of an optical fiber bundle according to claims 1-6, characterized in that: In step 1, the defect determination results of each connected domain are generated as follows: S101, collecting an end face image of the end face of the optical fiber bundle to be tested after being focused by a lens group, the end face image including a first end face image corresponding to a first light source and a second end face image corresponding to a second light source, wherein the second light source is an LED parallel surface light source, and its light source light is emitted from the far end of the optical fiber bundle to be tested; S102, extracting a first brightness value of each connected domain in the first end face image and a second brightness value of the corresponding connected domain in the second end face image, wherein the first brightness value is recorded as The second brightness value is recorded as Wherein K represents the number of connected domains corresponding to the optical fiber bundle to be detected; S103: Calculate the second brightness value of each connected region With the first brightness value The brightness ratio of k , k=1,2,…,K; S104, for {r k ,k=1,2,…,K} is fitted according to Gaussian distribution to generate Gaussian function parameters u1 and σ1; S105, when the brightness ratio r of any connected domain k ≥u1-3σ1, the connected domain is determined to be in a non-defective state; otherwise, the connected domain is determined to be in a defective state.

8. The method for detecting the spontaneous fluorescence intensity of an optical fiber bundle according to claim 7, wherein: Step 1 also includes a position adjustment step of the optical fiber bundle to be detected, so as to adjust the end face of the optical fiber bundle to be detected to an optimal position relative to the lens group, specifically: S001, configuring a plurality of preset positions for the optical fiber bundle to be tested, with the distances from the optical fiber bundle to the lens group increasing in sequence; S002, after moving the optical fiber bundle to be inspected to a middle position, adjusting the illumination of the first light source to an optimal illumination, collecting a first end face image of the optical fiber bundle to be inspected, and calculating the focus; S003, keep the current illumination of the first light source unchanged, move the optical fiber bundle to be detected to the next preset position, collect the first end face image again and calculate the focus, and judge whether the change amplitude of the focus between two adjacent times is less than the preset amplitude threshold. If so, the current position is the optimal position. If not, adjust the current position of the optical fiber bundle to be detected according to the judgment result, and repeat S003.

9. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method for detecting the autofluorescence intensity according to any one of claims 1 to 8 is implemented.

10. A device for detecting the spontaneous fluorescence intensity of an optical fiber bundle, characterized in that: The device comprises a first light source (1), a second light source (3), a clamping assembly for clamping an optical fiber bundle (15) to be detected, a lens group (7), a dichroic mirror (6), an image acquisition unit (5), and an image processing unit (4). The second light source (3) is arranged at the distal end of the optical fiber bundle (15) to be detected, and the light source light of the second light source (3) is injected from the distal end of the optical fiber bundle (15) to be detected and emitted from the proximal end, and then is focused by the lens group (7) and transmitted through the dichroic mirror (6); The first light source (1) is arranged above the dichroic mirror (6), and the light source light of the first light source (1) is reflected by the dichroic mirror (6) and focused by the lens group (7) before entering the proximal end of the optical fiber bundle (15) to be detected; The image acquisition unit (5) is used to acquire a first end face image of the optical fiber bundle (15) to be detected when the first light source (1) is turned on, and a second end face image of the optical fiber bundle (15) to be detected when the second light source (3) is turned on; The image processing unit (4) is used to execute the spontaneous fluorescence intensity detection method according to any one of claims 1 to 8.

Images