A medical mid-infrared 1720nm pulsed fiber laser

Abstract

The application discloses a kind of medical mid-infrared 1720nm pulsed fiber lasers, it is related to laser medical technical field, including the following steps: acquisition pulsed fiber laser data, respectively calculate thulium ion concentration uniformity index, laser energy intensity and each small target tissue ablation area ablation index, and then construct the thermal map matrix of each small thulium-doped fiber section, and draw the anti-fake color coding diagram of each target tissue ablation area, the spectral analysis technique in the method, multiple linear regression algorithm and convolution neural network algorithm are closely combined with modern information technology, the degree of uniformity of thulium ion concentration distribution and target tissue ablation degree are achieved in real time and comprehensive monitoring, so that the monitored data becomes more accurate index under the same conditions, significantly enhance the intelligent degree of medical mid-infrared 1720n pulsed fiber laser in use process.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of laser medical technology, and in particular to a medical mid-infrared 1720nm pulsed fiber laser. BACKGROUND

[0002] Traditional mid-infrared laser light sources have problems such as large size, low efficiency and complex maintenance, and are difficult to meet the needs of modern medicine for device miniaturization, portability and high stability. Fiber lasers, with their flexible transmission, high beam quality, high efficiency and easy integration, have become the ideal choice for the next generation of medical lasers. In the medical field, the application of laser technology is becoming more and more widespread, and the demand for specific wavelengths and pulse characteristics of laser is continuously growing. Mid-infrared band lasers have great potential in medical surgery and treatment due to their strong absorption characteristics with water molecules in biological tissues. The 1720nm wavelength laser is in the golden window of the mid-infrared band, and the water molecules have a high absorption coefficient, which can achieve precise tissue cutting and hemostasis. It has great application value in urology prostate surgery, dermatology plastic surgery and other surgical scenarios. Therefore, the development of a 1720nm pulsed fiber laser based on thulium-doped fiber has important significance for breaking through the key technical limitations and promoting the innovation and development of medical laser equipment.

[0003] Traditional medical mid-infrared pulsed fiber lasers often use thulium-doped fiber as gain medium, but there is a problem of uneven distribution of thulium-doped fiber ion concentration, which leads to gain saturation effect and reduces laser conversion efficiency. In addition, during the process of the medical mid-infrared pulsed fiber laser acting on the target tissue, it is difficult to analyze the nonlinear relationship between laser energy intensity and tissue ablation degree, making it difficult to accurately monitor the damage to the target tissue. Therefore, how to analyze the gain medium spectral data, pulsed fiber temperature data, laser data and target tissue data to solve the problems of traditional medical mid-infrared pulsed fiber lasers is the problem to be solved by the present application. Therefore, a medical mid-infrared 1720nm pulsed fiber laser is proposed. SUMMARY

[0004] To achieve the above purpose, the present application is realized by the following technical scheme: a medical mid-infrared 1720nm pulsed fiber laser, comprising the following steps:

[0005] Step one, collecting pulsed fiber laser data, including thulium-doped fiber spectral data, pulsed fiber data, laser data and target tissue data, providing a data basis for the realization of the subsequent steps;

[0006] Step two, feature extraction is performed on the thulium-doped fiber spectrum data, combined with the pulse fiber data, the thulium-doped fiber ion concentration distribution evaluation data is obtained, and normalization processing is performed to eliminate the dimension problem in subsequent calculation, and then the thulium-doped ion concentration uniformity index is calculated, and the uniformity of the thulium-doped ion concentration in each small thulium-doped fiber segment is evaluated;

[0007] Step three, the laser data is used to calculate the laser output wavelength accuracy, the pulse fiber temperature data and the multiple linear regression algorithm are combined to construct a laser energy intensity output model, and then the corresponding laser energy intensity is obtained; the ablation index of each small target tissue ablation area is calculated through the target tissue data, the ablation degree of each small target tissue ablation area is analyzed, and the ablation degree of each small target tissue ablation area is numbered;

[0008] Step four, according to the uniformity of the thulium-doped ion concentration in each small thulium-doped fiber segment, a heat map matrix of each small thulium-doped fiber segment is constructed; based on the ablation degree of each small target tissue ablation area, a forgery-resistant color coding map of each target tissue ablation area is drawn;

[0009] Step five, combined with the laser energy intensity, the ablation degree number of each small target tissue ablation area and the convolutional neural network algorithm, a target tissue damage analysis model is constructed;

[0010] Step six, according to the heat map matrix of each small thulium-doped fiber segment and the forgery-resistant color coding map of each target tissue ablation area, the uniformity of the thulium-doped ion concentration in each small thulium-doped fiber segment and the ablation degree of each small target tissue ablation area are analyzed, and according to the number of each small thulium-doped fiber segment and the number of each small target tissue ablation area, the thulium-doped ion concentration distribution uniformity abnormal corresponding each small thulium-doped fiber segment and the ablation degree abnormal corresponding each target tissue ablation area are located, and corresponding measures are taken to improve the thulium-doped ion concentration distribution uniformity abnormal and the ablation degree abnormal.

[0011] The further improvement of the technical scheme of the present application is that in step one, the acquisition process of the pulse fiber laser data includes:

[0012] The thulium-doped fiber is divided into several segments, each small thulium-doped fiber segment is obtained, and the target tissue ablation area is divided into several equal area regions, and each small target tissue ablation area is obtained;

[0013] Different types of collection devices are deployed to collect thulium-doped fiber spectrum data, pulse fiber data, laser data and target tissue data, wherein the different types of collection devices include a broadband light source, a spectrum analyzer, a laser pump source, a tunable laser, an optical power meter, a distributed fiber temperature measurement system, an optical time domain reflectometer, a wavelength meter, a light spot analyzer, a high-speed photodetector, an oscilloscope, an optoacoustic imaging system, a backscattering light diagnostic system, an optical coherence tomography system and a fiber grating temperature monitoring system;

[0014] The thulium-doped fiber spectrum data includes the absorption spectrum, fluorescence spectrum and gain spectrum of the trivalent thulium ion in the thulium-doped fiber; the pulse fiber data is the temperature and length of each section of the pulse fiber; the laser data includes the actual output laser wavelength of the laser, the spot diameter when the laser beam acts on the tissue surface and the pulse frequency of the laser pulse sequence; and the target tissue data includes the optoacoustic signal intensity, backscattering light intensity, thermal damage depth and temperature of the target tissue when the ablation area of the target tissue receives laser action.

[0015] The above-mentioned pulse fiber includes a thulium-doped fiber and also includes other types of fibers. In the implementation of the function of a medical mid-infrared 1720nm pulse fiber laser in the present application, the type of pulse fiber mainly used is a thulium-doped fiber. Therefore, the ion concentration distribution evaluation data of the thulium-doped fiber can be analyzed to evaluate the uniformity of the ion concentration distribution of the thulium-doped fiber.

[0016] The pulse fiber data, laser data and target tissue data are subjected to data cleaning and normalization processing, and the thulium-doped fiber spectrum data is subjected to baseline correction, wavelength calibration and spectral smoothing processing. The baseline correction is used to eliminate the interference of the fiber matrix material, the detector noise or the ambient light; the wavelength calibration is used to correct the wavelength accuracy error of the spectrometer; the spectral smoothing processing is used to reduce high-frequency noise and highlight characteristic peaks. Time stamps are respectively assigned to the preprocessed pulse fiber laser data of various types, the assigned time stamps are adjusted, the collection time of the thulium-doped fiber spectrum data, the pulse fiber data, the laser data and the target tissue data is synchronized, the thulium-doped fiber spectrum data, the pulse fiber data, the laser data and the target tissue data are integrated, and a pulse fiber laser data set is generated.

[0017] The further improvement of the technical scheme of the present application is that, in step two, the process of obtaining the thulium-doped fiber ion concentration distribution evaluation data through feature extraction and normalizing the same includes:

[0018] The thulium-doped fiber ion concentration distribution evaluation data includes the absorption coefficient, gain coefficient and gain saturation threshold power of each small thulium-doped fiber section, and the peak wavelength and full width at half maximum of the fluorescence spectrum corresponding to each small thulium-doped fiber section.

[0019] The characteristic peak detection algorithm is used to identify the characteristic absorption peak wavelength of the trivalent thulium ion from the absorption spectrum of the trivalent thulium ion in the thulium-doped fiber; according to the rare earth ion spectrum theory, the energy level transition corresponding to the characteristic absorption peak of the trivalent thulium ion is determined; the absorbance is read at the characteristic absorption peak wavelength of the trivalent thulium ion; according to the Lambert-Beer law, the absorption coefficients of the small thulium-doped fiber segments are calculated in combination with the lengths of the pulse fibers;

[0020] The spectral analysis technology is used to extract the intensity and wavelength of the fluorescence from the fluorescence spectrum of the trivalent thulium ion in the thulium-doped fiber; the derivative method is used to determine the peak position of the fluorescence spectrum, and then the peak wavelength corresponding to the peak position is extracted; the two fluorescence wavelengths corresponding to the half fluorescence intensity are extracted according to the peak wavelength of the fluorescence spectrum; and the full width at half maximum of the fluorescence spectrum corresponding to each small thulium-doped fiber segment is calculated by the absolute value of the difference between the two extracted fluorescence wavelengths.

[0021] The signal gain linear fitting method and the saturation curve nonlinear fitting method are combined to extract the gain coefficient and the gain saturation threshold power of each small thulium-doped fiber segment from the gain spectrum of the trivalent thulium ion in the thulium-doped fiber.

[0022] The absorption coefficient, the gain coefficient and the gain saturation threshold power of each small thulium-doped fiber segment extracted by the characteristic extraction, and the peak wavelength and the full width at half maximum of the fluorescence spectrum corresponding to each small thulium-doped fiber segment are subjected to Z-score normalization processing.

[0023] The further improvement of the technical scheme of the present application is that, in step two, the process of calculating the thulium ion concentration uniformity index and evaluating the uniformity degree of the thulium ion concentration distribution in each small thulium-doped fiber segment comprises:

[0024] The weighted average dispersion method is used to calculate the thulium ion concentration uniformity index in combination with the Z-score normalized thulium ion concentration distribution evaluation data.

[0025] When the thulium ion concentration uniformity index is lower than 0.25, the thulium ion concentration in each small thulium-doped fiber segment corresponds to a low distribution uniformity degree; when the thulium ion concentration uniformity index is between 0.25 and 0.45, the thulium ion concentration in each small thulium-doped fiber segment corresponds to a medium distribution uniformity degree; and when the thulium ion concentration uniformity index is higher than 0.45, the thulium ion concentration in each small thulium-doped fiber segment corresponds to a high distribution uniformity degree.

[0026] The further improvement of the technical scheme of the present application is that, in step three, the process of calculating the laser output wavelength accuracy, constructing a laser energy intensity output model in combination with the multiple linear regression algorithm, and then obtaining the corresponding laser energy intensity comprises:

[0027] The target output laser wavelength of the laser is set as 1720nm, the output wavelength accuracy of the laser is calculated through the absolute value of the difference between the actual output laser wavelength of the laser and the target output laser wavelength, and the output wavelength accuracy of the laser is normalized by Z-score and integrated into the pulse fiber laser dataset after normalization;

[0028] The temperature of each section of the pulse fiber, the spot diameter when the laser beam acts on the tissue surface, the pulse frequency of the laser pulse sequence and the output wavelength accuracy of the laser in the pulse fiber laser dataset are extracted, and the extracted data are divided into a first training set and a first test set according to a ratio of 8:2;

[0029] The first training set data are used to learn the linear relationship between the temperature of each section of the pulse fiber, the spot diameter when the laser beam acts on the tissue surface, the pulse frequency of the laser pulse sequence, the output wavelength accuracy of the laser and the laser energy intensity by combining a multiple linear regression algorithm, taking the first training set data as input and taking the laser energy intensity as output, so as to train a laser energy intensity output model;

[0030] The first test set data are input into the laser energy intensity output model, the regression coefficient and the intercept term of the laser energy intensity output model are adjusted, the performance of the laser energy intensity output model is optimized, and the laser energy intensity output model is obtained;

[0031] The corresponding laser energy intensity is output by combining the current temperature of each section of the pulse fiber, the spot diameter when the laser beam acts on the tissue surface, the pulse frequency of the laser pulse sequence and the output wavelength accuracy of the laser, and the laser energy intensity is integrated into the pulse fiber laser dataset.

[0032] The further improvement of the technical scheme of the present application is that in step three, the process of calculating the ablation index of each small target tissue ablation region, analyzing the ablation degree of each small target tissue ablation region and numbering the ablation degree of each small target tissue ablation region comprises:

[0033] According to the principle of cooperatively evaluating the ablation degree of each small target tissue ablation region according to the target tissue data, the principle can be understood as follows: the photoacoustic signal intensity of the target tissue ablation region when the target tissue ablation region is subjected to laser action reflects the energy absorption efficiency, which is the premise of ablation; the backscattering light intensity of the target tissue ablation region when the target tissue ablation region is subjected to laser action reflects the damage degree of the tissue structure; the thermal damage depth of the target tissue ablation region when the target tissue ablation region is subjected to laser action reflects the ablation range; the temperature of the target tissue ablation region when the target tissue ablation region is subjected to laser action reflects the thermal effect intensity; the ablation index of each small target tissue ablation region is calculated by using the preprocessed target tissue data and combining a nonlinear product model formula, and the calculation process is as follows:

[0034]

[0035] wherein, AQ i is the ablation index of each small target tissue ablation area, and respectively are the photoacoustic signal intensity, backscattering light intensity, thermal damage depth and temperature of the target tissue ablation area after normalization processing when the target tissue ablation area is subjected to laser action, and i is the number of each small target tissue ablation area;

[0036] When the ablation index of each small target tissue ablation area is lower than 0.35, it corresponds to a low ablation degree; when the ablation index of each small target tissue ablation area is between 0.35 and 0.7, it corresponds to a medium ablation degree; and when the ablation index of each small target tissue ablation area is higher than 0.7, it corresponds to a high ablation degree;

[0037] The ablation degrees of each small target tissue ablation area are numbered, and the ablation degrees of each small target tissue ablation area and the numbers thereof are integrated into the pulsed fiber laser data set;

[0038] Further improvement of the technical scheme of the present application is that in step four, the construction process of the thermal map matrix of each small thulium-doped fiber segment includes:

[0039] Each small thulium-doped fiber segment is numbered, the thermal map matrix structure is determined, the row dimension is set as the number of each small thulium-doped fiber segment, and the column dimension is set as the distribution uniformity of the thulium ion concentration in each small thulium-doped fiber segment;

[0040] According to the color mapping rule, a continuous color scale is used to represent the high, medium and low distribution uniformity of the thulium ion concentration in each small thulium-doped fiber segment from light to dark, and the thermal map matrix of each small thulium-doped fiber segment is constructed;

[0041] The interpretation of the thermal map matrix is that the thermal map matrix of each small thulium-doped fiber segment is used to display the distribution uniformity of the thulium ion concentration in each small thulium-doped fiber segment and the corresponding number thereof, and according to the number, the corresponding small thulium-doped fiber segment is retrieved, and subsequent measures are only taken for the small thulium-doped fiber segment corresponding to the number, thereby reducing the cost resources and realizing the positioning of the small thulium-doped fiber segment corresponding to the abnormal distribution uniformity of the thulium ion concentration.

[0042] Further improvement of the technical scheme of the present application is that in step four, the construction process of the thermal map matrix of each small thulium-doped fiber segment includes:

[0043] The color coding technology is used to select green, yellow and red, the printing color is calibrated by using the Pantone color card, the color is ensured to be correct, and the green, yellow and red are respectively associated with the low ablation degree, the medium ablation degree and the high ablation degree of each small target tissue ablation area.

[0044] According to the numbering of each small target tissue ablation area, the numbering technology is combined to label each small target tissue ablation area, and the vector graphics software is used to arrange each small target tissue ablation area in order.

[0045] The printing precision needs to be adjusted to more than 300 dpi to ensure that the micron-level texture is clear and identifiable, and distortion may occur during copying, and then the anti-fake color coding diagram of each target tissue ablation area is drawn.

[0046] The further improvement of the technical scheme of the application is that in step five, the construction process of the target tissue damage analysis model includes:

[0047] The laser energy intensity in the pulse fiber laser dataset and the ablation degree number of each small target tissue ablation area are extracted, the current extracted data is divided into a second training set and a second test set, and the proportion of the second training set and the second test set is 7:3.

[0048] The laser energy intensity is used as the input, and the ablation degree number of each small target tissue ablation area is used as the output, the nonlinear relationship between the laser energy intensity and the ablation degree number of each small target tissue ablation area is learned, and the target tissue damage analysis model is trained by combining the second training set data and the convolutional neural network algorithm.

[0049] The second test set data is input into the target tissue damage analysis model, the output result of the target tissue damage analysis model is compared with the actual ablation degree number of each small target tissue ablation area, the performance of the target tissue damage analysis model is evaluated, the parameters of the target tissue damage analysis model are adjusted, the target tissue damage analysis model is optimized, and finally the target tissue damage analysis model is obtained.

[0050] Through the target tissue damage analysis model, the nonlinear relationship between the laser energy intensity and the ablation degree number of each small target tissue ablation area is obtained, the accuracy of the output result of the target tissue damage analysis model is improved by continuously adjusting the parameters of the target tissue damage analysis model, and the ablation degree of each small target tissue ablation area is obtained by analyzing the laser energy intensity, and then the anti-fake color coding diagram of each target tissue ablation area is updated, thereby saving the monitoring cost.

[0051] A further improvement to the technical solution of this invention lies in the fact that, in step six, the process of evaluating the ablation regions of each target tissue corresponding to abnormalities in the uniformity of thulium-doped ion concentration distribution and abnormalities in ablation degree, and taking corresponding improvement measures, includes:

[0052] Analyzing the thermal matrix of each small thulium-doped fiber segment, the uniformity of thulium-doped ion concentration distribution in each segment was obtained based on the color depth of continuous color levels. Using the row dimension as a reference, the corresponding small thulium-doped fiber segment number was retrieved. When the thulium-doped ion concentration in the small thulium-doped fiber segment has a high uniformity distribution, it indicates that the thulium-doped ions are uniformly distributed in the fiber core layer with no concentration gradient, resulting in high and uniform pump light absorption efficiency and stable laser mode. The existing fiber manufacturing process for the corresponding small thulium-doped fiber segment is retained to ensure the stability of doping uniformity. A pump source matched to the fiber absorption peak is used to maximize energy coupling efficiency, which can be used for high-precision surgery. The stable laser output brought by high uniformity achieves the advantages of clear tissue ablation boundaries and minimal thermal damage. When the thulium-doped ion concentration in the small thulium-doped fiber segment has a medium uniformity distribution, it indicates that there are slight local concentration fluctuations of thulium-doped ions, which may lead to local overheating or mode instability. By employing a gradient refractive index design in the inner cladding, the non-uniformity of pump light absorption caused by the ion concentration gradient is compensated by adjusting the inner cladding diameter or doping distribution. This optimizes the thermal conductivity of the corresponding small thulium-doped fiber segment clamping structure, promptly dissipating heat generated by local hot spots and preventing cracking of the glass matrix due to thermal stress. Pulse width modulation technology is used to shorten the duration of high-power pulses in the corresponding small thulium-doped fiber segment, reducing the heat accumulation effect. When the thulium-doped ion concentration in the small thulium-doped fiber segment is low and uniform, it indicates that the thulium-doped ion concentration exhibits significant spatial non-uniformity, which may cause severe mode distortion, power jumps, or fiber damage. Unqualified small thulium-doped fiber segments are eliminated. Segmented pumping technology is adopted, with independent pump sources set in the corresponding small thulium-doped fiber segments. The pump energy of each segment is dynamically adjusted according to the concentration distribution. Chirped pulse amplification technology is introduced to broaden, amplify, and compress the pulse sequence, reducing the peak power density and avoiding nonlinear effects such as self-phase modulation and four-wave mixing.

[0053] According to the color of each small target tissue ablation area in the anti-fake color coding map of each target tissue ablation area, the ablation degree of each small target tissue ablation area is analyzed, the corresponding number of each small target tissue ablation area is searched according to the number mark, when the small target tissue ablation area is green, the corresponding low ablation degree indicates that only slight thermal damage occurs in the corresponding small target tissue ablation area, and the coagulation or vaporization threshold is not reached, and the ablation scheme of the corresponding small target tissue ablation area is maintained; when the small target tissue ablation area is yellow, the corresponding medium ablation degree indicates that coagulative necrosis occurs in the corresponding small target tissue ablation area, and there is a reversible thermal damage zone at the edge, intermittent irradiation is adopted, heat relaxation time is used to reduce the damage of the normal small target tissue ablation area with reduced ablation degree, single-point irradiation is changed to spiral scanning and fence scanning, the corresponding small target tissue ablation area is uniformly covered, and local over-ablation is reduced; when the small target tissue ablation area is red, the corresponding high ablation degree indicates that the tissue is vaporized, carbonized or even perforated, and there is irreversible thermal damage at the edge, which may be accompanied by bleeding and perforation risk, and physiological saline injection and low-temperature gas are used to reduce the corresponding small target tissue ablation area to below 37 DEG C, reduce the expansion of the carbonization range, and combine laser and other energy forms to complementarily adjust the ablation demand.

[0054] The beneficial effects of the present application are: a medical mid-infrared 1720nm pulsed fiber laser in the present application, compared with the traditional medical mid-infrared pulsed fiber laser, the spectral analysis technology, multivariate linear regression algorithm and convolutional neural network algorithm in the method of the present application are closely combined with modern information technology, the thulium-doped fiber spectrum data, pulsed fiber temperature data, laser output parameters and target tissue ablation data are accurately captured, and then the thulium ion concentration uniformity index, laser energy intensity and ablation index of each small target tissue ablation area are obtained, the real-time and comprehensive monitoring of the thulium ion concentration distribution uniformity and target tissue ablation degree is achieved, the abnormal area is located by constructing a heat map matrix and an anti-fake color coding map, the problems of low gain efficiency caused by uneven thulium ion concentration and inaccurate monitoring of the ablation degree of the target tissue of the traditional medical mid-infrared pulsed fiber laser are solved, and it is ensured that the method in the present application can be used in a more accurate range to refine the dynamic monitoring standard of a medical mid-infrared 1720nm pulsed fiber laser, so that the monitored data becomes a more accurate index under the same conditions, the research and application of this method significantly enhances the intelligent degree of the medical mid-infrared 1720nm pulsed fiber laser in use. BRIEF DESCRIPTION OF DRAWINGS

[0055] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed in the embodiments. Obviously, the drawings described below are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings.

[0056] Figure 1 A flowchart of a medical mid-infrared 1720nm pulsed fiber laser. DETAILED DESCRIPTION

[0057] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will combine the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0058] As shown in Figure 1 The present application provides a medical mid-infrared 1720nm pulsed fiber laser, which consists of the following steps:

[0059] Step 101, collecting pulsed fiber laser data, the pulsed fiber laser data including thulium-doped fiber spectrum data, pulsed fiber data, laser data and target tissue data, which provides a data basis for the realization of subsequent steps;

[0060] Step 102, extracting features from the thulium-doped fiber spectrum data, combining the pulsed fiber data to obtain thulium-doped fiber ion concentration distribution evaluation data, and performing normalization processing on it to eliminate the dimension problem in subsequent calculation, and then calculating the thulium-doped ion concentration uniformity index and evaluating the distribution uniformity of thulium-doped ion concentration in each small thulium-doped fiber segment;

[0061] Step 103, using the laser data to calculate the laser output wavelength accuracy, combining the pulsed fiber temperature data and the multiple linear regression algorithm to construct a laser energy intensity output model, and then obtaining the corresponding laser energy intensity; through the target tissue data, calculating the ablation index of each small target tissue ablation area, analyzing the ablation degree of each small target tissue ablation area, and numbering the ablation degree of each small target tissue ablation area;

[0062] Step 104, constructing a heat map matrix of each small thulium-doped fiber segment according to the distribution uniformity of thulium-doped ion concentration in each small thulium-doped fiber segment; based on the ablation degree of each small target tissue ablation area, drawing a forgery-resistant color coding map of each target tissue ablation area;

[0063] Step 105, combined with the laser energy intensity, the ablation degree number of each small target tissue ablation area and the convolution neural network algorithm, a target tissue damage analysis model is constructed;

[0064] Step 106, according to the heat map matrix of each small thulium-doped fiber segment and the anti-fake color coding map of each target tissue ablation area, the uniformity of the distribution of thulium ion concentration in each small thulium-doped fiber segment and the ablation degree of each small target tissue ablation area are analyzed respectively, and according to the number of each small thulium-doped fiber segment and the number of each small target tissue ablation area, each small thulium-doped fiber segment corresponding to the abnormal thulium ion concentration distribution uniformity and each target tissue ablation area corresponding to the abnormal ablation degree are located, and corresponding measures are taken to improve the problems of abnormal thulium ion concentration distribution uniformity and abnormal ablation degree.

[0065] In step 101, the collection process of the pulsed fiber laser data includes:

[0066] The thulium-doped fiber is divided into several segments, each small thulium-doped fiber segment is obtained, and each small target tissue ablation area is obtained by dividing the target tissue ablation area into several areas of the same area.

[0067] Different types of collection devices are deployed to collect thulium-doped fiber spectrum data, pulsed fiber data, laser data and target tissue data, wherein the different types of collection devices include a broadband light source, a spectrum analyzer, a laser pump source, a tunable laser, an optical power meter, a distributed fiber temperature measurement system, an optical time domain reflectometer, a wavelength meter, a light spot analyzer, a high-speed photodetector, an oscilloscope, an optoacoustic imaging system, a backscattering light diagnostic system, an optical coherence tomography system and a fiber grating temperature monitoring system.

[0068] The thulium-doped fiber spectrum data includes the absorption spectrum, fluorescence spectrum and gain spectrum of the trivalent thulium ion in the thulium-doped fiber; the pulsed fiber data is the temperature and length of each segment of the pulsed fiber; the laser data includes the actual output laser wavelength of the laser, the spot diameter when the laser beam acts on the tissue surface and the pulse frequency of the laser pulse sequence; the target tissue data includes the optoacoustic signal intensity, the backscattering light intensity, the thermal damage depth and the temperature of the target tissue ablation area when the target tissue ablation area receives laser action.

[0069] The above pulsed fiber includes a thulium-doped fiber and other types of fibers, and in the implementation of a medical mid-infrared 1720nm pulsed fiber laser function, the thulium-doped fiber is mainly used, so that the thulium-doped fiber ion concentration distribution evaluation data can be analyzed to evaluate the thulium-doped fiber ion concentration distribution uniformity problem.

[0070] Specifically, in combination with a broadband light source and a spectrum analyzer, the absorption spectrum of the trivalent thulium ion in the thulium-doped fiber is collected; in combination with the spectrum analyzer and a laser pumping source, the fluorescence spectrum of the trivalent thulium ion in the thulium-doped fiber is collected; in combination with a tunable laser, an optical power meter and the spectrum analyzer, the gain spectrum of the trivalent thulium ion in the thulium-doped fiber is collected; the temperature and length of each pulse fiber are collected by using a distributed fiber temperature measurement system and an optical time domain reflectometer respectively; the actual output laser wavelength of the laser and the spot diameter when the laser beam acts on the surface of the tissue are collected by using a wavelength meter and a spot analyzer respectively; the pulse frequency of the laser pulse sequence is collected by using a high-speed photodetector and an oscilloscope; the photoacoustic signal intensity, the backscattering light intensity, the thermal damage depth and the temperature of the ablation area of the target tissue when the target tissue is subjected to laser action are collected by using a photoacoustic imaging system, a backscattering light diagnosis system, an optical coherence tomography system and a fiber grating temperature monitoring system respectively.

[0071] The pulse fiber data, the laser data and the target tissue data are subjected to data cleaning and normalization processing, the thulium-doped fiber spectrum data is subjected to baseline correction, wavelength calibration and spectrum smoothing processing, wherein the baseline correction is used to eliminate the interference of the fiber matrix material, the detector noise or the ambient light; the wavelength calibration is used to correct the wavelength accuracy error of the spectrometer; the spectrum smoothing processing is used to reduce the high-frequency noise and highlight the characteristic peaks; the time stamps of the preprocessed pulse fiber laser data of various types are respectively allocated, the allocated time stamps are adjusted, the collection time of the thulium-doped fiber spectrum data, the pulse fiber data, the laser data and the target tissue data is synchronized, the thulium-doped fiber spectrum data, the pulse fiber data, the laser data and the target tissue data are integrated, and the pulse fiber laser data set is generated.

[0072] In step 102, the process of obtaining the thulium-doped fiber ion concentration distribution evaluation data by feature extraction and normalizing the thulium-doped fiber ion concentration distribution evaluation data includes:

[0073] The thulium-doped fiber ion concentration distribution evaluation data includes the absorption coefficient, the gain coefficient and the gain saturation threshold power of each small thulium-doped fiber segment, and the peak wavelength and the full width at half maximum of the fluorescence spectrum corresponding to each small thulium-doped fiber segment;

[0074] The characteristic absorption peak wavelength of the trivalent thulium ion is identified from the absorption spectrum of the trivalent thulium ion in the thulium-doped fiber by using a feature peak detection algorithm, the energy level transition corresponding to the characteristic absorption peak of the trivalent thulium ion is determined according to the rare earth ion spectrum theory, the absorbance is read at the characteristic absorption peak wavelength of the trivalent thulium ion, and the absorption coefficient of each small thulium-doped fiber segment is calculated according to the Lambert-Beer law in combination with the length of each pulse fiber, wherein the calculation formula is: wherein, α x is the absorption coefficient of each small thulium-doped fiber segment, A xThe light absorbance read at the wavelength of the characteristic absorption peak of the trivalent thulium ion, L is the length of each section of the pulsed fiber;

[0075] The intensity and wavelength of the fluorescence are extracted from the fluorescence spectrum of the trivalent thulium ion in the thulium-doped fiber by using spectral analysis technology, the peak position of the fluorescence spectrum is determined by using the derivative method, and the two fluorescence wavelengths corresponding to the half fluorescence intensity are extracted according to the peak wavelength of the fluorescence spectrum. The full width at half maximum of the fluorescence spectrum corresponding to each small thulium-doped fiber section is calculated by the absolute value of the difference between the two extracted fluorescence wavelengths.

[0076] The gain coefficient and gain saturation threshold power of each small thulium-doped fiber section are extracted from the gain spectrum of the trivalent thulium ion in the thulium-doped fiber by combining the linear fitting method of signal gain and the nonlinear fitting method of saturation curve.

[0077] The absorption coefficient, gain coefficient, gain saturation threshold power, peak wavelength and full width at half maximum of the fluorescence spectrum of each small thulium-doped fiber section are subjected to Z-score normalization processing, wherein the Z-score normalization formula is wherein x ' is the actual value of the data, μ is the mean of the data, and σ is the standard deviation of the data. is the actual value of the data, μ is the mean of the data, and σ is the standard deviation of the data.

[0078] In step 102, the process of calculating the thulium ion concentration uniformity index and evaluating the uniformity of the thulium ion concentration distribution in each small thulium-doped fiber section includes:

[0079] The thulium ion concentration uniformity index is calculated by using the weighted average dispersion method combined with the Z-score normalized thulium ion concentration distribution evaluation data, and the specific calculation process includes: first, the standard deviation and mean of each Z-score normalized thulium ion concentration distribution evaluation data are calculated, the ratio of the standard deviation to the mean of each thulium ion concentration distribution evaluation data is used to obtain the absorption coefficient dispersion coefficient, the gain coefficient dispersion coefficient, the gain saturation threshold power dispersion coefficient, and the peak wavelength dispersion coefficient and the full width at half maximum dispersion coefficient of the fluorescence spectrum, respectively, the absorption coefficient dispersion coefficient, the gain coefficient dispersion coefficient, the gain saturation threshold power dispersion coefficient, and the peak wavelength dispersion coefficient and the full width at half maximum dispersion coefficient are assigned weights, and the formula for calculating the thulium ion concentration uniformity index is: U = 1-(wα a + w g g + w p p sat + w γ g spec + w β g d , wherein U is a thulium ion concentration uniformity index, w α , w g , w p , w γ and w β are weight of the absorption coefficient dispersion coefficient, the gain coefficient dispersion coefficient, the gain saturation threshold power dispersion coefficient, and the peak wavelength dispersion coefficient and the full width at half maximum dispersion coefficient of the fluorescence spectrum, respectively, a, g, p sat , g spec and g d are the absorption coefficient dispersion coefficient, the gain coefficient dispersion coefficient, the gain saturation threshold power dispersion coefficient, and the peak wavelength dispersion coefficient and the full width at half maximum dispersion coefficient of the fluorescence spectrum, respectively;

[0080] When the thulium ion concentration uniformity index is less than 0.25, the thulium ion concentration in each small thulium-doped fiber segment corresponds to a low distribution uniformity; when the thulium ion concentration uniformity index is between 0.25 and 0.45, the thulium ion concentration in each small thulium-doped fiber segment corresponds to a medium distribution uniformity; and when the thulium ion concentration uniformity index is greater than 0.45, the thulium ion concentration in each small thulium-doped fiber segment corresponds to a high distribution uniformity.

[0081] In step 103, the laser output wavelength accuracy is calculated, and a laser energy intensity output model is constructed by combining a multiple linear regression algorithm, and then the corresponding laser energy intensity is obtained. The process includes:

[0082] The target output laser wavelength of the laser is set to 1720 nm. The laser output wavelength accuracy is calculated by the absolute value of the difference between the actual output laser wavelength of the laser and the target output laser wavelength, and the laser output wavelength accuracy is normalized by Z-score and integrated into the pulsed fiber laser dataset;

[0083] The temperature of each segment of the pulsed fiber, the spot diameter when the laser beam acts on the surface of the tissue, the pulse frequency of the laser pulse sequence, and the laser output wavelength accuracy in the pulsed fiber laser dataset are extracted. The extracted data is divided into a first training set and a first test set in a ratio of 8:2;

[0084] The first training set data is used in combination with the multiple linear regression algorithm, the first training set data is taken as input, and the laser energy intensity is taken as output. The linear relationship between the temperature of each section of the pulse fiber, the spot diameter when the laser beam acts on the tissue surface, the pulse frequency of the laser pulse sequence, the laser output wavelength accuracy and the laser energy intensity is learned, and the laser energy intensity output model is trained.

[0085] The first test set data is input into the laser energy intensity output model, the regression coefficient and the intercept term of the laser energy intensity output model are adjusted, the performance of the laser energy intensity output model is optimized, and the laser energy intensity output model is obtained. The expression of the laser energy intensity output model is as follows:

[0086]

[0087] Wherein, E is the laser energy intensity, and The regression coefficients of the laser energy intensity output model are T, R, F and D, respectively, and T, R, F and D are the temperature of each section of the pulse fiber, the spot diameter when the laser beam acts on the tissue surface, the pulse frequency of the laser pulse sequence and the laser output wavelength accuracy, and θ are the intercept term and error term of the laser energy intensity output model, respectively.

[0088] In combination with the current temperature of each section of the pulse fiber, the spot diameter when the laser beam acts on the tissue surface, the pulse frequency of the laser pulse sequence and the laser output wavelength accuracy, the corresponding laser energy intensity is output, and the laser energy intensity is integrated into the pulse fiber laser data set.

[0089] In step 103, the ablation index of each small target tissue ablation region is calculated, the ablation degree of each small target tissue ablation region is analyzed, and the ablation degree of each small target tissue ablation region is numbered. The process includes:

[0090] According to the principle of evaluating the ablation degree of each small target tissue ablation region according to the target tissue data, the principle can be understood as follows: the photoacoustic signal intensity of the target tissue ablation region when it is subjected to laser action reflects the energy absorption efficiency, which is the premise of ablation; the backscattering light intensity of the target tissue ablation region when it is subjected to laser action reflects the damage degree of the tissue structure; the thermal damage depth of the target tissue ablation region when it is subjected to laser action reflects the ablation range; the temperature of the target tissue ablation region when it is subjected to laser action reflects the thermal effect intensity. The ablation index of each small target tissue ablation region is calculated by using the preprocessed target tissue data and combining the nonlinear product model formula, and the calculation process is as follows:

[0091]

[0092] Wherein, AQi an ablation index of each small target tissue ablation region, and respectively, are the photoacoustic signal intensity, backscattering light intensity, thermal damage depth and temperature of the target tissue ablation region after normalization processing, and i is the number of each small target tissue ablation region;

[0093] When the ablation index of each small target tissue ablation region is lower than 0.35, it corresponds to low ablation degree; when the ablation index of each small target tissue ablation region is between 0.35 and 0.7, it corresponds to medium ablation degree; when the ablation index of each small target tissue ablation region is higher than 0.7, it corresponds to high ablation degree;

[0094] The ablation degrees of each small target tissue ablation region are numbered, and the ablation degrees of each small target tissue ablation region and their numbers are integrated into the pulsed fiber laser data set;

[0095] In step 104, the construction process of the thermal map matrix of each small thulium-doped fiber segment includes:

[0096] Each small thulium-doped fiber segment is numbered, the thermal map matrix structure is determined, the row dimension is set as the number of each small thulium-doped fiber segment, and the column dimension is set as the distribution uniformity of thulium ion concentration in each small thulium-doped fiber segment.

[0097] According to the color mapping rule, a continuous color scale is used to represent the high, medium and low distribution uniformity of thulium ion concentration in each small thulium-doped fiber segment from light to dark, and the thermal map matrix of each small thulium-doped fiber segment is constructed.

[0098] The interpretation of the thermal map matrix is that the thermal map matrix of each small thulium-doped fiber segment is used to display the distribution uniformity of thulium ion concentration in each small thulium-doped fiber segment and its corresponding number. According to the number, the corresponding small thulium-doped fiber segment is retrieved, and subsequent measures are only taken for the small thulium-doped fiber segment corresponding to the number, which reduces the cost resources and realizes the positioning of the small thulium-doped fiber segment corresponding to the abnormal distribution uniformity of thulium ion concentration.

[0099] In step 104, the drawing process of the anti-fake color coding map of each target tissue ablation region includes:

[0100] Using color coding technology, green, yellow and red are selected, and the printing color is calibrated using Pantone color card to ensure that the color is correct. Green, yellow and red are respectively associated with low, medium and high ablation degrees of each small target tissue ablation region.

[0101] In combination with the numbering annotation technology, each small target tissue ablation area is annotated according to the numbering of each small target tissue ablation area, and the vector graphics software is used to arrange each small target tissue ablation area in order of numbering.

[0102] The printing accuracy needs to be adjusted to 300 dpi or more to ensure that the micron-level texture is clear and identifiable, and distortion may occur during copying, thereby drawing the anti-counterfeiting color coding diagram of each target tissue ablation area.

[0103] In step 105, the construction process of the target tissue damage analysis model includes:

[0104] The laser energy intensity in the pulse fiber laser dataset and the ablation degree number of each small target tissue ablation area are extracted, and the currently extracted data is divided into a second training set and a second test set, and the proportion of the second training set and the second test set is 7:3;

[0105] In combination with the second training set data and the convolutional neural network algorithm, the laser energy intensity is taken as the input, and the ablation degree number of each small target tissue ablation area is taken as the output, the nonlinear relationship between the laser energy intensity and the ablation degree number of each small target tissue ablation area is learned, and the target tissue damage analysis model is trained;

[0106] The second test set data is input into the target tissue damage analysis model, the output result of the target tissue damage analysis model is compared with the actual ablation degree number of each small target tissue ablation area, the performance of the target tissue damage analysis model is evaluated, the parameters of the target tissue damage analysis model are adjusted, the target tissue damage analysis model is optimized, and finally the target tissue damage analysis model is obtained;

[0107] Through the target tissue damage analysis model, the nonlinear relationship between the laser energy intensity and the ablation degree number of each small target tissue ablation area is obtained, the accuracy of the output result of the target tissue damage analysis model is improved by continuously adjusting the parameters of the target tissue damage analysis model, and the ablation degree of each small target tissue ablation area is obtained by analyzing the laser energy intensity, and the anti-counterfeiting color coding diagram of each target tissue ablation area is updated, thereby saving the monitoring cost.

[0108] In step 106, the process of evaluating each target tissue ablation area corresponding to the thulium ion concentration distribution uniformity abnormality and the ablation degree abnormality and taking corresponding measures for improvement includes:

[0109] The heat map matrix of each small thulium-doped fiber section is analyzed, and according to the color depth of the continuous color scale, the uniformity of the thulium ion concentration distribution in each small thulium-doped fiber section is obtained. Taking the row dimension as the reference, the corresponding small thulium-doped fiber section number is searched out. When the thulium ion concentration in the small thulium-doped fiber section is high, it indicates that the thulium ions are uniformly distributed in the fiber core layer, there is no concentration gradient, the pump light absorption efficiency is high and uniform, the laser mode is stable, the existing fiber manufacturing process of the corresponding small thulium-doped fiber section is retained, the stability of the doping uniformity is ensured, the pump source matched with the fiber absorption peak is used, the energy coupling efficiency is maximized, and it can be used for high-precision surgery. The stable laser output brought by high uniformity realizes the advantages of clear tissue ablation boundary and small thermal damage; when the thulium ion concentration in the small thulium-doped fiber section is medium, it indicates that there is a slight local concentration fluctuation of thulium ions, which may cause local overheating or mode instability. In the corresponding small thulium-doped fiber section, the inner cladding graded refractive index design is adopted, the inner cladding diameter or doping distribution is adjusted, the inhomogeneity of pump light absorption caused by ion concentration gradient is compensated, the heat conduction efficiency of the clamping structure of the corresponding small thulium-doped fiber section is optimized, the heat generated by local hot spots is promptly discharged, the glass substrate is prevented from cracking due to thermal stress, and the pulse width modulation technology is used to shorten the duration of high-power pulses in the corresponding small thulium-doped fiber section, and the heat accumulation effect is reduced; when the thulium ion concentration in the small thulium-doped fiber section is low, it indicates that the thulium ion concentration presents significant spatial inhomogeneity, which may cause serious mode distortion, power jump or fiber damage. The unqualified small thulium-doped fiber section is rejected, the segmented pumping technology is adopted, the independent pump source is arranged in the corresponding small thulium-doped fiber section, the pump energy of each section is dynamically adjusted according to the concentration distribution, the chirped pulse amplification technology is introduced, the pulse sequence is expanded, amplified and compressed, the peak power density is reduced, and the nonlinear effects such as self-phase modulation and four-wave mixing are avoided.

[0110] According to the color of each small target tissue ablation area in the anti-counterfeiting color-coded map of each target tissue ablation area, the ablation degree of each small target tissue ablation area is analyzed, the number corresponding to each small target tissue ablation area is searched according to the number mark, when the small target tissue ablation area is green, it corresponds to low ablation degree, indicating that only slight thermal injury occurs in the corresponding small target tissue ablation area, and the coagulation or vaporization threshold is not reached, the ablation scheme of the corresponding small target tissue ablation area is maintained; when the small target tissue ablation area is yellow, it corresponds to medium ablation degree, indicating that coagulative necrosis occurs in the corresponding small target tissue ablation area, and there is a reversible thermal injury zone at the edge, intermittent irradiation is adopted, heat relaxation time is used to reduce the damage of normal small target tissue ablation area with high ablation degree, single point irradiation is changed to spiral scanning and fence scanning, which uniformly covers the corresponding small target tissue ablation area and reduces local overablation; when the small target tissue ablation area is red, it corresponds to high ablation degree, indicating that the tissue is vaporized, carbonized or even perforated, and there is irreversible thermal injury at the edge, which may be accompanied by bleeding and perforation risk, physiological saline injection and low temperature gas are used to reduce the corresponding small target tissue ablation area to below 37℃, reduce the expansion of carbonization range, and combine laser and other energy forms to complementarily adjust the ablation demand.

[0111] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of changes or replacements within the technical range disclosed in the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A medical mid-infrared 1720nm pulsed fiber laser, characterized in that: Includes the following steps: Data from a pulsed fiber laser is acquired, including thulium-doped fiber spectral data, pulsed fiber data, laser data, and target tissue data. The data acquisition process of the pulsed fiber laser includes: The thulium-doped fiber is divided into several segments to obtain each small thulium-doped fiber segment. The target tissue ablation area is divided into several regions of the same area to obtain each small target tissue ablation area. The thulium-doped fiber spectral data includes the absorption spectrum, fluorescence spectrum, and gain spectrum of trivalent thulium ions in the thulium-doped fiber; the pulsed fiber data includes the temperature and length of each segment of the pulsed fiber; the laser data includes the actual output laser wavelength, the spot diameter when the laser beam acts on the tissue surface, and the pulse frequency of the laser pulse sequence; the target tissue data includes the photoacoustic signal intensity, backscattered light intensity, thermal damage depth, and temperature of the ablation area of ​​the target tissue when it receives laser action. The pulsed fiber data, laser data, and target tissue data are cleaned and normalized. The thulium-doped fiber spectral data undergoes baseline correction, wavelength calibration, and spectral smoothing. Timestamps are assigned to each type of preprocessed pulsed fiber laser data, and the assigned timestamps are adjusted to synchronize the acquisition time of the thulium-doped fiber spectral data, pulsed fiber data, laser data, and target tissue data. The thulium-doped fiber spectral data, pulsed fiber data, laser data, and target tissue data are then integrated to generate a pulsed fiber laser dataset. Feature extraction is performed on the spectral data of the thulium-doped fiber, and combined with pulse fiber data, evaluation data on the thulium-doped fiber ion concentration distribution is obtained. The data is then normalized, and the uniformity index of thulium-doped ion concentration is calculated to evaluate the uniformity of thulium-doped ion concentration distribution in each small thulium-doped fiber segment. The thulium-doped fiber ion concentration distribution evaluation data includes the absorption coefficient, gain coefficient and gain saturation threshold power of each small thulium-doped fiber segment, as well as the peak wavelength and full width at half maximum (FWHM) of the corresponding fluorescence spectrum of each small thulium-doped fiber segment. A characteristic peak detection algorithm is used to identify the characteristic absorption peak wavelength of trivalent thulium ions from the absorption spectrum of trivalent thulium ions in the thulium-doped fiber. According to the rare earth ion spectroscopy theory, the energy level transition corresponding to the characteristic absorption peak of the trivalent thulium ions is determined, and the absorbance is read at the characteristic absorption peak wavelength of the trivalent thulium ions. Based on the Lambert-Beer law and the length of each pulse fiber segment, the absorption coefficient of each small thulium-doped fiber segment is calculated. By combining the linear fitting method of signal gain and the nonlinear fitting method of saturation curve, the gain coefficient and gain saturation threshold power of each small thulium-doped fiber segment are extracted from the gain spectrum of trivalent thulium ions in the thulium-doped fiber. The absorption coefficient, gain coefficient, and gain saturation threshold power of each small thulium-doped fiber segment extracted from the features, as well as the peak wavelength and full width at half maximum (FWHM) of the corresponding fluorescence spectrum of each small thulium-doped fiber segment, were normalized using Z-score. The process of calculating the uniformity index of thulium-doped ion concentration and evaluating the uniformity of thulium-doped ion concentration distribution in each small thulium-doped fiber segment includes: The uniformity index of thulium-doped fiber concentration was calculated by using the weighted average dispersion method and combining the evaluation data of thulium-doped fiber ion concentration distribution after Z-score normalization. When the thulium-doped ion concentration uniformity index is below 0.25, the thulium-doped ion concentration in each small thulium-doped fiber segment corresponds to a low degree of uniformity; when the thulium-doped ion concentration uniformity index is between 0.25 and 0.45, the thulium-doped ion concentration in each small thulium-doped fiber segment corresponds to a medium degree of uniformity; when the thulium-doped ion concentration uniformity index is above 0.45, the thulium-doped ion concentration in each small thulium-doped fiber segment corresponds to a high degree of uniformity. Using the laser data, the laser output wavelength accuracy is calculated. Combining the pulsed fiber temperature data with a multiple linear regression algorithm, a laser energy intensity output model is constructed to obtain the corresponding laser energy intensity. Using the target tissue data, the ablation index of each small target tissue ablation region is calculated, the ablation degree of each small target tissue ablation region is analyzed, and the ablation degree of each small target tissue ablation region is numbered. The process of calculating the laser output wavelength accuracy, combining it with a multiple linear regression algorithm to construct a laser energy intensity output model, and then obtaining the corresponding laser energy intensity includes: The target output wavelength of the laser is set to 1720nm. The output wavelength accuracy of the laser is calculated by the absolute value of the difference between the actual output wavelength and the target output wavelength. The output wavelength accuracy is then normalized by Z-score and integrated into the pulsed fiber laser dataset. The temperature of each segment of pulsed fiber, the spot diameter of the laser beam when it acts on the tissue surface, the pulse frequency of the laser pulse sequence, and the laser output wavelength accuracy are extracted from the pulsed fiber laser dataset. The extracted data is then divided into a first training set and a first test set. Using the first training set data and combined with the multiple linear regression algorithm, the first training set data is used as input and the laser energy intensity is used as output to learn the linear relationship between the temperature of each segment of the pulsed optical fiber, the spot diameter when the laser beam acts on the tissue surface, the pulse frequency of the laser pulse sequence, the laser output wavelength accuracy and the laser energy intensity, and to train the laser energy intensity output model. The first test set data is input into the laser energy intensity output model. The regression coefficients and intercept terms of the laser energy intensity output model are adjusted to optimize the performance of the laser energy intensity output model and obtain the laser energy intensity output model. By combining the current temperature of each segment of the pulsed fiber, the spot diameter of the laser beam when it acts on the tissue surface, the pulse frequency of the laser pulse sequence, and the laser output wavelength accuracy, the corresponding laser energy intensity is output, and the laser energy intensity is integrated into the pulsed fiber laser data set. Based on the uniformity of thulium ion concentration distribution in each small thulium-doped fiber segment, a heat map matrix for each small thulium-doped fiber segment is constructed; based on the ablation degree of each small target tissue ablation region, an anti-counterfeiting color code map of each target tissue ablation region is drawn. By combining the laser energy intensity, the ablation degree numbering of each small target tissue ablation region, and the convolutional neural network algorithm, a target tissue damage analysis model is constructed. Based on the heat map matrix of each small thulium-doped fiber segment and the anti-counterfeiting color code map of each target tissue ablation region, the uniformity of thulium-doped ion concentration distribution in each small thulium-doped fiber segment and the ablation degree of each small target tissue ablation region are analyzed. According to the numbers of each small thulium-doped fiber segment and each small target tissue ablation region, the small thulium-doped fiber segment corresponding to the abnormal uniformity of thulium-doped ion concentration distribution and the target tissue ablation region corresponding to the abnormal ablation degree are located respectively. Corresponding measures are taken to improve the problems of abnormal uniformity of thulium-doped ion concentration distribution and abnormal ablation degree. The process of calculating the ablation index of each small target tissue ablation region, analyzing the ablation degree of each small target tissue ablation region, and numbering the ablation degree of each small target tissue ablation region includes: Based on the principle of collaboratively evaluating the ablation degree of each small target tissue ablation region using data from various target tissues, the ablation index of each small target tissue ablation region is calculated using preprocessed target tissue data and a nonlinear multiplication model formula. The calculation process is as follows: ； in, The ablation index for the ablation region of each small target organization. , , and These represent the photoacoustic signal intensity, backscattered light intensity, thermal damage depth, and temperature of the ablation region of the target tissue after normalization when subjected to laser irradiation, respectively, where i is the number of ablation regions of each small target tissue. When the ablation index of each small target tissue ablation region is below 0.35, it corresponds to low ablation degree; when the ablation index of each small target tissue ablation region is between 0.35 and 0.7, it corresponds to medium ablation degree; when the ablation index of each small target tissue ablation region is above 0.7, it corresponds to high ablation degree. The ablation degree of each small target tissue ablation region is numbered, and the ablation degree and number of each small target tissue ablation region are integrated into the pulsed fiber laser dataset.

2. A medical mid-infrared 1720nm pulsed fiber laser according to claim 1, characterized in that: The data acquisition process for the pulsed fiber laser also includes: Different types of acquisition devices are deployed to collect thulium-doped fiber spectral data, pulsed fiber data, laser data, and target tissue data. These different types of acquisition devices include broadband light sources, spectral analyzers, laser pump sources, tunable lasers, optical power meters, distributed fiber optic temperature measurement systems, optical time-domain reflectometers, wavelength meters, spot analyzers, high-speed photodetectors, oscilloscopes, photoacoustic imaging systems, backscattered light diagnostic systems, optical coherence tomography systems, and fiber optic grating temperature monitoring systems.

3. A medical mid-infrared 1720nm pulsed fiber laser according to claim 2, characterized in that: The process of obtaining thulium-doped fiber ion concentration distribution evaluation data through feature extraction and normalizing it further includes: Using spectral analysis techniques, the fluorescence intensity and wavelength are extracted from the fluorescence spectrum of trivalent thulium ions in thulium-doped fiber. Combined with the derivative method, the peak position of the fluorescence spectrum is determined, and then its corresponding peak wavelength is determined. Based on the peak wavelength of the fluorescence spectrum, two fluorescence wavelengths corresponding to half the fluorescence intensity are extracted. By using the absolute value of the difference between the two extracted fluorescence wavelengths, the full width at half maximum (FWHM) of the fluorescence spectrum corresponding to each small thulium-doped fiber segment is calculated.

4. A medical mid-infrared 1720nm pulsed fiber laser according to claim 1, characterized in that: The process of constructing the heatmap matrix of each small thulium-doped fiber segment includes: Each small thulium-doped fiber segment is numbered, the heatmap matrix structure is determined, the row dimension is set to the number of each small thulium-doped fiber segment, and they are arranged in ascending order according to the number of each small thulium-doped fiber segment. The column dimension is the uniformity of the distribution of thulium-doped ion concentration in each small thulium-doped fiber segment. Based on the color mapping rules, a continuous color scale is used, from light to dark, to represent the high, medium, and low distribution uniformity of thulium ion concentration in each small thulium-doped fiber segment, respectively, to construct a heat map matrix for each small thulium-doped fiber segment.

5. A medical mid-infrared 1720nm pulsed fiber laser according to claim 4, characterized in that: The process of drawing the anti-counterfeiting color code map of each target tissue ablation area includes: Using color coding technology, green, yellow, and red were selected, and the printing colors were calibrated using the Pantone color chart. Green, yellow, and red were then associated with the low, medium, and high ablation degrees of the ablation regions of the various small target tissues, respectively. Combining numbering and labeling technology, each small target tissue ablation region is labeled according to its number, and vector graphics software is used to arrange the small target tissue ablation regions in numerical order. The printing resolution needs to be adjusted to 300 dpi or higher, and then the anti-counterfeiting color code map of the ablation area of ​​each target tissue is drawn.

6. A medical mid-infrared 1720nm pulsed fiber laser according to claim 5, characterized in that: The process of constructing the target tissue damage analysis model includes: Extract the laser energy intensity and ablation degree number of each small target tissue ablation region from the pulsed fiber laser dataset, and divide the currently extracted data into a second training set and a second test set; By combining the second training set data and the convolutional neural network algorithm, the laser energy intensity is used as the input and the ablation degree number of each small target tissue ablation region is used as the output. The nonlinear relationship between the laser energy intensity and the ablation degree number of each small target tissue ablation region is learned, and the target tissue damage analysis model is trained. The second test set data is input into the target tissue damage analysis model. The output results of the target tissue damage analysis model are compared with the ablation degree numbers of each small target tissue ablation area. The performance of the target tissue damage analysis model is evaluated, the parameters of the target tissue damage analysis model are adjusted, the target tissue damage analysis model is optimized, and then the final target tissue damage analysis model is obtained.

7. A medical mid-infrared 1720nm pulsed fiber laser according to claim 6, characterized in that: The process of assessing the ablation regions of each target tissue corresponding to abnormalities in the uniformity of thulium-doped ion concentration distribution and ablation degree, and taking corresponding measures to improve them, includes: Analyzing the heatmap matrix of each small thulium-doped fiber segment, the uniformity of thulium ion concentration distribution in each segment is obtained based on the color depth of continuous color levels. Using the row dimension as a reference, the corresponding small thulium-doped fiber segment number is retrieved. When the thulium ion concentration in the small thulium-doped fiber segment has a high uniformity distribution, the existing fiber manufacturing process for that segment is retained, and a pump source matched to the fiber absorption peak is used to maximize energy coupling efficiency. When the thulium ion concentration in the small thulium-doped fiber segment has a medium uniformity distribution, the existing fiber manufacturing process for that segment is retained, and a pump source matching the fiber absorption peak is used to maximize energy coupling efficiency. The inner cladding adopts a graded refractive index design to optimize the thermal conductivity of the corresponding small thulium-doped fiber segment clamping structure. Pulse width modulation technology is used to shorten the duration of high-power pulses in the corresponding small thulium-doped fiber segment. When the thulium-doped ion concentration in the small thulium-doped fiber segment is low and the distribution is uniform, the unqualified small thulium-doped fiber segment is removed. Segmented pumping technology is adopted, with independent pump sources set in the corresponding small thulium-doped fiber segment. The pump energy of each segment is dynamically adjusted according to the concentration distribution. Chirped pulse amplification technology is introduced to broaden, amplify and compress the pulse sequence to reduce the peak power density. Based on the color of each small target tissue ablation area in the anti-counterfeiting color coding map of each target tissue ablation area, the ablation degree of each small target tissue ablation area is analyzed. According to the number label, the corresponding number of each small target tissue ablation area is retrieved. When the small target tissue ablation area is green, it corresponds to a low ablation degree, and the ablation plan for the corresponding small target tissue ablation area is maintained. When the small target tissue ablation area is yellow, it corresponds to a medium ablation degree. Intermittent irradiation is adopted, and thermal relaxation time is used to reduce damage to the surrounding small target tissue ablation areas with normal ablation degree. Single-point irradiation is changed to spiral scanning and fence scanning to uniformly cover the corresponding small target tissue ablation area and reduce local over-ablation. When the small target tissue ablation area is red, it corresponds to a high ablation degree. Physiological saline spray and low temperature gas are used to cool the corresponding small target tissue ablation area to below 37°C to reduce the expansion of carbonization range. The ablation requirements are adjusted complementaryly by combining laser and other energy forms.

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