Image quality control method for confocal endomicroscope

Abstract

The present application discloses an image quality control method for a confocal endomicroscope. First, a brightness signal value adjustment range, a laser power adjustment range, and a detection power adjustment range are determined; then, the brightness of each image in a screened image set is analyzed to extract a parameter of a maximum brightness value of each image; and then, an average value of the maximum brightness values of all images in the screened image set is compared with the several predetermined adjustment ranges, so that an image quality adjustment operation, instead of experience-based adjustment, can be determined as soon as possible, thereby effectively improving the efficiency and quality of image quality adjustment.

Description

Image quality control method of a confocal microscopic endoscope

[0001] This application claims priority to the Chinese patent application No. 202410977274.X filed on July 22, 2024 in the Chinese Patent Office and entitled "Image quality control method of a confocal microscopic endoscope", the entire content of which is incorporated herein by reference. The disclosure of all applications cited herein and contained in this application is incorporated herein by reference in its entirety as part of this application and is not admitted to be prior art against this application. TECHNICAL FIELD

[0002] The present application relates to the field of optical imaging, and more particularly, to an image quality control method of a confocal microscopic endoscope. BACKGROUND

[0003] A confocal microscopic endoscope is a medical device that can enter the natural cavity of the human body through the channel of a gastroscope, colonoscope, cholangioscope, etc., to obtain local histological images to achieve precise diagnosis of micro-lesions and early cancer in the digestive tract, biliary and pancreatic ducts, etc. Because of its fast, accurate and non-invasive characteristics, it may replace traditional endoscopic biopsy and pathological examination in the near future and become the main means and device for the diagnosis of early lesions and cancer in the digestive tract, biliary and pancreatic ducts, etc.

[0004] A confocal microscopic endoscope generally includes a confocal main machine and a confocal probe, which are connected by a coupling objective lens. The confocal probe is used to enter the human body for detection and imaging, and the confocal main machine is used to generate excitation light, which is irradiated to the tissue site containing a fluorescent agent through the confocal probe, thereby exciting a fluorescent signal, which returns along the original path and is received and analyzed by the confocal main machine, ultimately realizing in-vivo imaging through the instrument channel of a gastroscope, colonoscope, cholangioscope, etc.

[0005] When a confocal microscopic endoscope is used and debugged, it needs to be debugged to appropriate image quality parameters for different tissue sites to obtain the best imaging effect. There is no effective method in the prior art to adjust the related parameters for different imaging objects to obtain good image quality. SUMMARY

[0006] A series of simplified concepts are introduced in the summary section, which will be further described in detail in the specific embodiments section. The summary section of the present application does not mean to attempt to limit the key features and essential technical features of the claimed technical solutions, nor to attempt to determine the protection scope of the claimed technical solutions.

[0007] In a first aspect, the present application provides an image quality control method of a confocal microscopic endoscope, comprising the following steps:

[0008] S1, determining a brightness signal value adjustment range of the confocal microscopic endoscope, determining a laser power adjustment range, and determining a detection power adjustment range;

[0009] S2, using the confocal microscopic endoscope to perform multiple imaging on an object containing a fluorescent agent to obtain a screening image set;

[0010] S3, performing brightness analysis on each of the screening image set to obtain a brightness greater value of each image;

[0011] S4, judging whether an average value of the brightness greater values of the screening image set is within the brightness signal value adjustment range, if yes, no image quality adjustment operation is needed, and if no, determining an image quality adjustment operation based on a comparison between the average value of the brightness greater values of the screening image set and the brightness signal value adjustment range, and a comparison between a current laser power of the confocal microscopic endoscope and the laser power adjustment range and a comparison between a current detection power and the detection power adjustment range;

[0012] S5, adjusting parameters of the confocal microscopic endoscope according to the image quality adjustment operation determined in S4, and repeating S2-S4 until the average value of the brightness greater values of the screening image set is within the brightness signal value adjustment range.

[0013] Through the above technical solution, the brightness signal value adjustment range, the laser power adjustment range, and the detection power adjustment range are first determined, then the brightness of each image in the screening image set is analyzed, the brightness greater value of each image is extracted, and then the average value of the brightness greater values of all images in the screening image set is compared with the several adjustment ranges determined in S1, so that the image quality adjustment operation can be determined as soon as possible without relying on experience debugging, and the efficiency and quality of image quality adjustment can be effectively improved.

[0014] Further, the image quality adjustment operation includes adjusting one of the fluorescent agent concentration, the laser power, and the detection power.

[0015] Further, S2 specifically includes:

[0016] S201, selecting a laser power within the laser power adjustment range as a current laser power of the confocal microscopic endoscope, selecting a detection power within the detection power adjustment range as a current detection power of the confocal microscopic endoscope, and obtaining multiple imaging results of the confocal microscopic endoscope as a cache image set;

[0017] S202, performing a screening operation on the cache image set to obtain a screening image set.

[0018] Further, the screening operation specifically includes:

[0019] S2021, noise value statistics is performed on all images in the cache image set;

[0020] S2022, a noise threshold is set, images with noise values lower than the noise threshold are retained, and the filtered image set is obtained.

[0021] Further, the filtering operation is specifically:

[0022] S2021, noise value statistics is performed on all images in the cache image set;

[0023] S2022, noise values of all images are sorted in ascending order, images with noise values in the top N / 2 or (N+1) / 2 are retained, and the filtered image set is obtained, wherein N represents the number of images in the cache image set.

[0024] Further, S3 is specifically:

[0025] S301, the intensity I of each pixel in each image in the filtered image set is counted i , i = 1, 2, 3, …, n, n is the total number of pixels of each image;

[0026] S302, the intensity average value m of each image is calculated

[0027] S303, the larger value k of brightness is calculated, k = am, a > 1, a represents a weighting coefficient.

[0028] Further, 1.3 ≤ a ≤ 1.8.

[0029] Further, in S4, the image quality adjustment operation is specifically:

[0030] When the average value of the larger value of brightness of the filtered image set is less than the minimum value of the brightness signal value adjustment range, if the current laser power ≠ the maximum value of the laser power adjustment range, the image quality adjustment operation is to increase the laser power; if the current laser power = the maximum value of the laser power adjustment range, and the current detector power = the maximum value of the detection power adjustment range, the image quality adjustment operation is to increase the concentration of fluorescent agent; if the current laser power = the maximum value of the laser power adjustment range, and the current detector power ≠ the maximum value of the detection power adjustment range, the image quality adjustment operation is to increase the detection power.

[0031] When the average value of the maximum value of the brightness of the screening image set > the maximum value of the brightness signal value adjustment range, if the current laser power ≠ the minimum value of the laser power adjustment range, the image quality adjustment operation is to reduce the laser power; if the current laser power = the minimum value of the laser power adjustment range, and the current detector power ≠ the minimum value of the detection power adjustment range, the image quality adjustment operation is to reduce the detection power; if the current laser power = the minimum value of the laser power adjustment range, and the current detector power = the minimum value of the detection power adjustment range, the image quality adjustment operation is to reduce the concentration of the fluorescent agent.

[0032] Further, the laser power adjustment range in S1 is determined according to the minimum laser power and the maximum laser power of the laser, the detection power adjustment range is determined according to the minimum detection power and the maximum detection power of the detector, and the brightness signal value adjustment range is determined according to the minimum brightness value and the maximum brightness value that can be reached by the hardware in the confocal microscopic endoscope.

[0033] The present application provides an image quality control method of a confocal microscopic endoscope, and other advantages, objects and features of the present application will be apparent from the following description, and will be understood by those skilled in the art through research and practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0034] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are included to provide a description of the preferred embodiments and are not intended to limit the scope of the present application. Moreover, like reference numerals designate like parts throughout the several views in the drawings. In the drawings:

[0035] FIG. 1 is a flow chart of an image quality control method of a confocal microscopic endoscope according to an embodiment of the present application;

[0036] FIG. 2 is a judgment flow chart of S4 in the image quality control method of a confocal microscopic endoscope according to an embodiment of the present application. DETAILED DESCRIPTION

[0037] The terms "first", "second", "third", "fourth" and the like in the description and in the claims of the present application and above-mentioned drawings, if any, are used for distinguishing between similar objects and not necessarily for describing a specific sequential or chronological order. It is to be understood that the use of the terms so construed herein is merely for convenience and only to aid in understanding the application and in no way define the scope of the application. It is also to be understood that the description and the examples, while indicating certain embodiments of the application, are given by way of example and are not intended to limit the scope of the application unless otherwise specifically indicated. Thereafter, the application is described and exemplified by the following embodiments thereof, in conjunction with the accompanying drawings.

[0038] Referring to FIG. 1, the present application proposes a confocal microscopic endoscope image quality control method, comprising the following steps:

[0039] S1, determining the brightness signal value adjustment range of the confocal microscopic endoscope, determining the laser power adjustment range, and determining the detection power adjustment range;

[0040] Specifically, the laser power adjustment range is determined according to the minimum laser power and the maximum laser power of the laser. The minimum laser power and the maximum laser power of the laser are determined when the laser is manufactured, and are usually recorded in the equipment manual. The detection power adjustment range is determined according to the minimum detection power and the maximum detection power of the detector. The minimum detection power and the maximum detection power of the detector are determined when the detector is manufactured, and are usually recorded in the equipment manual. The brightness signal value adjustment range is determined according to the maximum brightness value that can be reached by the hardware in the confocal microscopic endoscope multiplied by the relevant empirical coefficient. The hardware here can be an AD sampling chip, and the maximum brightness value is determined by the number of bits of the AD sampling chip. The minimum value of the empirical coefficient can be 0.68, and the maximum value can be 0.99.

[0041] S2, using the confocal microscopic endoscope to image the object containing the fluorescent agent multiple times to obtain a screening image set;

[0042] Specifically, when imaging, a certain laser power between the minimum value and the maximum value of the laser power, and a certain detection power between the minimum value and the maximum value of the detection power are selected, and then the confocal microscopic endoscope is used to image multiple times to obtain multiple images. On the one hand, the randomness of the image samples is ensured, and on the other hand, the multiple images provide sufficient reference samples for subsequent analysis and provide accurate references for subsequent image quality adjustment operations.

[0043] S3, performing brightness analysis on each of the screening image set to obtain a larger value of brightness of each image;

[0044] Specifically, a plurality of images are obtained, and a larger value of brightness of each image is obtained, thereby providing a basis for subsequently obtaining an average value of the larger value of brightness.

[0045] S4, judging whether the average value of the larger value of brightness of the screening image set is within the brightness signal value adjustment range, if yes, no image quality adjustment operation is needed, if not, based on the comparison between the average value of the larger value of brightness of the screening image set and the brightness signal value adjustment range, and the comparison between the current laser power of the confocal microscopic endoscope and the laser power adjustment range and the comparison between the current detection power and the detection power adjustment range, the image quality adjustment operation is determined.

[0046] Specifically, while the brightness signal comparison is performed, the laser power and the detection power of the microscopic endoscope still need to be compared, because although a certain laser power between the minimum value and the maximum value of the laser power and a certain detection power between the minimum value and the maximum value of the detection power are selected at S2, the laser power and the detection power will change due to external factors such as use time and vibration in the actual use process, and therefore the laser power and the detection power still need to be judged in the final decision, and finally the related parameters are adjusted reasonably based on the comprehensive judgment to determine the image quality adjustment operation.

[0047] The present application firstly determines the brightness signal value adjustment range, the laser power adjustment range and the detection power adjustment range, then analyzes the brightness of each image in the screening image set, extracts the parameter of the larger value of brightness of each image, and compares the average value of the larger value of brightness of all images in the screening image set with the several adjustment ranges determined in S1, thereby the image quality adjustment operation can be determined as soon as possible without relying on experience debugging, and the efficiency and quality of the image quality adjustment can be effectively improved.

[0048] S5, adjusting the parameters of the confocal microscopic endoscope according to the image quality adjustment operation determined in S4, repeating S2-S4 until the average value of the larger value of brightness of the screening image set is within the brightness signal value adjustment range.

[0049] When the average value of the larger value of brightness of the screening image set is within the brightness signal value adjustment range, it indicates that the image quality has met the demand, and no further image quality adjustment is needed, otherwise, S2-S4 need to be repeated, the parameters of the confocal microscopic endoscope in S2 are determined according to the image quality adjustment operation determined in the previous S4, and a new screening image set is obtained to judge and adjust the image quality.

[0050] Specifically, the image quality adjustment operation includes adjusting one of the fluorescent agent concentration, the laser power, and the detection power. According to the comparison result in S4, one of the confocal microscopic endoscopy parameters is adjusted, the parameter target is clear, and the image quality can be effectively and accurately improved. More specifically, the adjustment of the fluorescent agent concentration can be to increase the fluorescent agent concentration or to decrease the fluorescent agent concentration. However, in actual clinical application, it is difficult to decrease the fluorescent agent concentration after the fluorescent agent has been injected. Therefore, a certain time can be waited for part of the fluorescent agent to be absorbed by the tissue to be imaged, so as to achieve the adjustment effect of decreasing the fluorescent agent concentration. The adjustment of the laser power can be to increase the laser power or to decrease the laser power, and the adjustment of the detection power can be to increase the detection power or to decrease the detection power.

[0051] Specifically, the confocal microscopic endoscopy is based on fluorescence imaging of a fluorescent agent, and the fluorescent agent is usually sodium fluorescein. Due to differences in imaging objects and imaging environments, the concentration of sodium fluorescein, the laser power, and the detection power all affect the quality of imaging. Moreover, these parameters will change dynamically with the imaging objects and the imaging environments. However, it is not necessarily possible to capture the best imaging moment in actual imaging. Therefore, when an image with good image quality is desired to be obtained, the concentration of the fluorescent agent, the laser power, and the detection power need to be comprehensively considered to reasonably determine how to adjust the parameters.

[0052] In some specific embodiments, S2 specifically includes:

[0053] S201, selecting a laser power in a laser power adjustment range as a current laser power of the confocal microscopic endoscopy, selecting a detection power in a detection power adjustment range as a current detection power of the confocal microscopic endoscopy, and obtaining multiple imaging results of the confocal microscopic endoscopy as a cache image set.

[0054] S202, performing a screening operation on the cache image set to obtain a screening image set.

[0055] Specifically, the screening operation here can be naked-eye screening, that is, deleting images with obvious noise and retaining the remaining images as the screening image set, or algorithm screening, which is more objective and accurate. In some embodiments, the screening operation specifically includes:

[0056] S2021, performing noise value statistics on all images in the cache image set;

[0057] S2022, setting a noise threshold, retaining images with noise values lower than the noise threshold, and obtaining the screening image set.

[0058] The noise values of all images in the cache image set are counted, and then a noise threshold is set. The images with noise values lower than the noise threshold are retained as the screening image set, and the images with noise values equal to or higher than the noise threshold are deleted.

[0059] In some embodiments, the screening operation is specifically:

[0060] S2021, count the noise values of all images in the cache image set;

[0061] S2022, sort the noise values of all images in ascending order, retain the images with noise values in the first N / 2 or (N+1) / 2 in the sorted order, and obtain the screening image set, wherein N represents the number of images in the cache image set.

[0062] The noise values of all images in the cache image set are counted, and are sorted in ascending order. The images with noise values in the first N / 2 or (N+1) / 2 in the sorted order are retained as the screening image set, and the other images are deleted. When N is even, the images with noise values in the first N / 2 in the sorted order are retained. When N is odd, the images with noise values in the first (N+1) / 2 in the sorted order are retained. The screening image set retained through the screening operation has higher image quality, and can reduce the calculation amount and difficulty of subsequent S3.

[0063] More specifically, when using an algorithm for screening, the specific operation of counting the noise values of all images is as follows: for each pixel point in the image to be screened, the variance of the pixel values in the neighborhood of the pixel point is calculated, and the formula is wherein δ 2 represents the variance of the pixel values in the neighborhood of a single pixel point in the image, r represents the number of pixels in the neighborhood, x j represents the pixel value in the neighborhood, μ represents the average value of the pixel values in the neighborhood, The total number of pixels in an image is n, and n δ 2 can be obtained, which are respectively The noise value of the image is counted as The pixel value variance can be used to accurately represent the noise level of the image.

[0064] In some embodiments, in order to obtain a screening image set with better quality, the selection of the noise threshold is also very important. The calculation formula of the noise threshold is: wherein ω represents the noise threshold, and α represents a coefficient,

[0065] For example, the average δ mean of the noise variances of the 50 images in S201 is counted respectively, and the coefficient can be taken as 1 / 50. Then the noise threshold is Then, the noise values in the cache image set are compared with the noise threshold ω one by one, and the images less than the noise threshold ω are retained, and finally the screening image set in S202 is obtained.

[0066] In some specific embodiments, as the noise variance mean of each of the 50 images in S201 is counted respectively, and after they are arranged in ascending order, a noise value set is formed, for example, {0.125, 0.341, 0.396, 0.732, …, 6.775, 9.216, 9.842}, then the top 25 images in the noise value ranking are taken as the screening image set.

[0067] In some specific embodiments, S3 is specifically:

[0068] S301, the intensity I of each pixel in each image in the screening image set is counted. i , i = 1, 2, 3, …, n, n is the total number of pixels of each image;

[0069] S302, the intensity average value m of each image is calculated.

[0070] S303, the larger value k of the brightness is calculated, k = am, a > 1, a represents the weighting coefficient.

[0071] Specifically, by counting the intensity of each pixel of each image in the screening image set, then obtaining the intensity average value, taking the intensity of a certain multiple (i.e. a) of the average value as the larger value k of the brightness of each image, preferably, 1.3 ≤ a ≤ 1.8, the weighting coefficient in this range can ensure that the finally confirmed larger value k of the brightness is in a suitable range.

[0072] When the screening image set of 25 images is obtained through the steps of S202, in S3, the intensity average value m of the 25 images needs to be counted in turn, and then a weighting coefficient a is selected to obtain the larger value k of the brightness of the 25 images in turn. The weighting coefficient a can be selected in the range of 1.3-1.8 as follows: if the current laser power is closer to the minimum value in the laser power adjustment range, the selection of a can be closer to 1.8, and if the current laser power is closer to the maximum value in the laser power adjustment range, the selection of a can be closer to 1.3.

[0073] In some specific embodiments, as shown in FIG. 2, in S4, the determination of the image quality adjustment operation is specifically:

[0074] When the average value of the maximum value of the brightness of the image set is less than the minimum value of the brightness signal value adjustment range, and the current laser power is not equal to the maximum value of the laser power adjustment range, the image quality adjustment operation is to increase the laser power; when the current laser power is equal to the maximum value of the laser power adjustment range and the current detector power is equal to the maximum value of the detector power adjustment range, the image quality adjustment operation is to increase the concentration of the fluorescent agent; when the current laser power is equal to the maximum value of the laser power adjustment range and the current detector power is not equal to the maximum value of the detector power adjustment range, the image quality adjustment operation is to increase the detection power; under this judgment condition, it is indicated that the image brightness has not reached the minimum brightness that can be realized by the imaging hardware, at this time, it is further judged whether the current laser power has reached the maximum value, if not, the laser power is directly increased, if yes, it is indicated that the image brightness cannot be enhanced by adjusting the laser power, then it is further judged whether the detection power has reached the maximum value, if yes, it is indicated that the weak image brightness is not caused by the laser power and the detection power, but by the insufficient concentration of the fluorescent agent, thus the concentration of the fluorescent agent can be directly increased, if not, the detector power can be directly increased.

[0075] When the average value of the maximum value of the brightness of the image set is greater than the maximum value of the brightness signal value adjustment range, and the current laser power is not equal to the minimum value of the laser power adjustment range, the image quality adjustment operation is to decrease the laser power; when the current laser power is equal to the minimum value of the laser power adjustment range and the current detector power is not equal to the minimum value of the detector power adjustment range, the image quality adjustment operation is to decrease the detection power; when the current laser power is equal to the minimum value of the laser power adjustment range and the current detector power is equal to the minimum value of the detector power adjustment range, the image quality adjustment operation is to decrease the concentration of the fluorescent agent. Under this judgment condition, it is indicated that the image brightness is too high, and thus needs to be reduced, therefore, the current laser power is compared with the laser power adjustment range, if the current laser power has not reached the minimum value, the laser power is directly decreased to reduce the image brightness; if the current laser power has reached the minimum value and the detection power has not reached the minimum value, the detection power is directly decreased; if the current laser power has reached the minimum value and the detection power has reached the minimum value, in practice, the tissue to be imaged generally has absorption to the fluorescent agent, and thus can wait for a certain period of time, so as to reduce the concentration of the fluorescent agent after part of the fluorescent agent is absorbed, thereby reducing the image brightness.

[0076] Through the comparison of S4, the conclusion that the image brightness is too strong or insufficient can be drawn, so as to quickly select the image quality adjustment operation, adjust the appropriate parameters, appropriately reduce / increase the image brightness, and thus improve the image quality.

[0077] If the screening image set is 25 images, the average value of the larger brightness values is obtained after summing the larger brightness values of the 25 images and dividing by 25. By comparing the average value of the larger brightness values of the screening image set with the comparison of the current laser power and the laser power adjustment range of the confocal microscopic endoscope and the comparison of the current detection power and the detection power adjustment range, the image quality adjustment operation can be quickly confirmed without relying on experience debugging, and the efficiency and quality of image quality adjustment can be effectively improved.

[0078] The above embodiments are only used to illustrate the technical solutions of the present application, but not limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application. Industrial applicability

[0079] The image quality control method of the confocal microscopic endoscope provided by the embodiments of the present application first determines the brightness signal value adjustment range, the laser power adjustment range, and the detection power adjustment range, then analyzes the brightness of each image in the screening image set, extracts the larger brightness value of each image as a parameter, and compares the average value of the larger brightness values of all images in the screening image set with the pre-determined adjustment ranges, so that the image quality adjustment operation can be determined as soon as possible without relying on experience debugging, and the efficiency and quality of image quality adjustment can be effectively improved. Therefore, the laser power determination model construction method and the laser power automatic adjustment method provided by the embodiments of the present application have industrial applicability.

Claims

1. A method of image quality control of a confocal endomicroscope, characterized in that The method comprises the following steps: S1, determining a brightness signal value adjustment range of the confocal microscopic endoscope, determining a laser power adjustment range, and determining a detection power adjustment range; S2, using the confocal microscopic endoscope to perform multiple imaging on an object containing a fluorescent agent to obtain a screening image set; S3, performing brightness analysis on each of the screening image set to obtain a larger brightness value of each image; S4, judging whether the average value of the larger brightness values of the screening image set is within the brightness signal value adjustment range, if yes, no image quality adjustment operation is needed, and if not, determining an image quality adjustment operation based on a comparison between the average value of the larger brightness values of the screening image set and the brightness signal value adjustment range, a comparison between the current laser power of the confocal microscopic endoscope and the laser power adjustment range, and a comparison between the current detection power and the detection power adjustment range; S5, adjusting parameters of the confocal microscopic endoscope according to the image quality adjustment operation determined in S4, and repeating S2-S4 until the average value of the larger brightness values of the screening image set is within the brightness signal value adjustment range.

2. The method of claim 1, wherein, The image quality adjustment operation comprises adjusting one of the fluorescent agent concentration, the laser power and the detection power.

3. The method of claim 2, wherein, S2 specifically comprises: S201, selecting a laser power within the laser power adjustment range as the current laser power of the confocal microscopic endoscope, selecting a detection power within the detection power adjustment range as the current detection power of the confocal microscopic endoscope, and obtaining multiple imaging results of the confocal microscopic endoscope as a cache image set; S202, performing a screening operation on the cache image set to obtain a screening image set.

4. The method of claim 3, wherein, The screening operation specifically comprises: S2021, performing noise value statistics on all images in the cache image set; S2022, setting a noise threshold, retaining images with noise values lower than the noise threshold, and obtaining the screening image set.

5. The method of claim 3, wherein, The screening operation specifically comprises: S2021, performing noise value statistics on all images in the cache image set; S2022, sorting noise values of all images in ascending order, retaining images with noise values in the first N / 2 or (N+1) / 2 positions, and obtaining the screening image set, wherein N represents the number of images in the cache image set.

6. The method of claim 2, wherein, S3 specifically comprises: S301, count each pixel intensity I in each image in the screening image set i , i = 1, 2, 3, …, n, n is the total number of pixels in each image; S302, find the intensity average value m of each image, S303, calculating a larger brightness value k, k=am, a>1, and a represents a weighting coefficient.

7. The method of claim 6, wherein, 1.3≤a≤1.8。 8. The method of claim 2, wherein, In S4, the determination of the image quality adjustment operation specifically comprises: When the average value of the larger brightness values of the screening image set is less than the minimum value of the brightness signal value adjustment range, if the current laser power is not equal to the maximum value of the laser power adjustment range, the image quality adjustment operation is to increase the laser power; if the current laser power is equal to the maximum value of the laser power adjustment range and the current detection power is equal to the maximum value of the detection power adjustment range, the image quality adjustment operation is to increase the fluorescent agent concentration; if the current laser power is equal to the maximum value of the laser power adjustment range and the current detection power is not equal to the maximum value of the detection power adjustment range, the image quality adjustment operation is to increase the detection power. When the average value of the maximum value of the brightness of the screening image set > the maximum value of the brightness signal value adjustment range, if the current laser power ≠ the minimum value of the laser power adjustment range, the image quality adjustment operation is to reduce the laser power; if the current laser power = the minimum value of the laser power adjustment range, and the current detector power ≠ the minimum value of the detection power adjustment range, the image quality adjustment operation is to reduce the detection power; if the current laser power = the minimum value of the laser power adjustment range, and the current detector power = the minimum value of the detection power adjustment range, the image quality adjustment operation is to reduce the concentration of the fluorescent agent.

9. The method of claim 1, wherein, The laser power adjustment range in S1 is determined according to the minimum laser power and the maximum laser power of the laser, the detection power adjustment range is determined according to the minimum detection power and the maximum detection power of the detector, and the brightness signal value adjustment range is determined according to the minimum brightness value and the maximum brightness value that can be reached by the hardware in the confocal microscopic endoscope.

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