Online real-time quantitative detection device for iCa in laser-induced breakdown spectroscopy dialysate

Abstract

The utility model relates to the technical field of solution electrolyte detection, and provides an on-line real-time quantitative detection device for iCa in laser-induced breakdown spectroscopy dialysate, which comprises a flowing module, a detection module and a control module, wherein the flowing module comprises an ellipsoidal sample pool, a dialysate pool and a power pump; the LIBS laser module comprises a first total reflective mirror, a second total reflective mirror, a laser diffusion lens group and a laser focusing lens group which are used for completely reflecting laser, and the second total reflective mirror is used for receiving reflected laser and generating high-intensity reflected laser; a dichroscope of the acquisition module is arranged between a laser diffusion lens group and a laser focusing lens group, plasma emitted light is reflected by the dichroscope and then is converged by a second converging lens, the light is coupled to a spectrograph after being collected and converged by an optical fiber, and an LIBS spectrum is acquired by a detector. The ellipsoidal sample pool is vertically placed, and the volume of the ellipsoidal sample pool is small, so that the concentration of electrolyte in dialysate is accurately monitored in real time, and the situation that the accuracy of real-time feedback of data is reduced due to excessive hysteresis effects is avoided.

Description

TECHNICAL FIELD

[0001] The utility model relates to solution electrolyte detection technical field especially relates to a kind of laser-induced breakdown spectroscopy dialysate iCa online real-time quantitative detection device. BACKGROUND

[0002] Local citric acid anticoagulation RCA has less bleeding complications, filter long service life and the like advantages, and has become the preferred anticoagulation mode of severe CRRT patient currently.RCA implementation principle is to block coagulation cascade by citric acid chelating calcium ions, to achieve the purpose of anticoagulation, so monitoring ion calcium (iCa) level is the basis to ensure the successful implementation of RCA.

[0003] iCa in blood or dialysate needs to be monitored frequently during RCA implementation, and bedside biochemical analyzer or traditional laboratory biochemical instrument is generally selected.However, the very low iCa level (about 0.2-0.4 mmol / L) in vitro during RCA treatment not only exceeds the measurement range of traditional laboratory biochemical instrument, but also consumes a lot of manpower due to frequent sampling, and the specimen transportation and detection time are relatively long;Bedside biochemical analyzer is convenient for very low iCa detection, but it is suitable for blood, and there is deviation in the determination of iCa in dialysate, and the cost of supporting consumables is huge, and at least several minutes of detection time is needed;Although access type ion selective electrode can achieve the purpose of real-time detection, whether the composition of ion selective electrode is toxic and the service life of electrode needs long-term observation, and it needs to be calibrated again each time it is used.Currently, there is no real-time online detection method for iCa, which limits the clinical application of RCA-CRRT.

[0004] Currently, LIBS method is used to determine the content of trace metal elements in dialysate, and the sample needs to be dried first, and then the solid sample is determined.At the same time, the calcium element concentration in dialysate is low, and the spectral line signal is difficult to detect, and total calcium and iCa are difficult to distinguish, and optimization is needed to achieve the detection accuracy and precision required by clinic.The conventional univariate spectral data processing method cannot meet the iCa detection requirements. UTILITY MODEL CONTENT

[0005] In view of the above problems, the utility model aims at providing a kind of laser-induced breakdown spectroscopy dialysate iCa online real-time quantitative detection device, comprising: flow module, the flow module includes the ellipsoidal sample cell for carrying dialysate sample, and the power pump for driving the dialysate sample in the ellipsoidal sample cell to flow into dialysate pool;

[0006] The LIBS laser module comprises a first full reflection mirror for fully reflecting laser, a second full reflection mirror for receiving reflected laser and generating high-intensity reflected laser, a laser diffusion lens group for expanding the high-intensity reflected laser, and a laser focusing lens group.

[0007] The collecting module is arranged between the laser diffusion lens group and the laser focusing lens group, the back-propagating plasma emission light is reflected by the dichroic mirror and then converged by a second converging lens, the converged plasma emission light is collected by an optical fiber, and the LIBS spectrum of the plasma emission light dispersed by the spectrometer is collected by a detector.

[0008] Preferably, the ellipsoidal sample cell is vertically placed, the input end section and the output end section of the ellipsoidal sample cell are located at the major axis, and the input end of the ellipsoidal sample cell is higher than the output end of the ellipsoidal sample cell.

[0009] Preferably, the short axis of the ellipsoidal sample cell is 30 mm, the input end section and the output end section of the ellipsoidal sample cell are 15 mm, and the input end and the output end of the ellipsoidal sample cell are smaller than the input end section and the output end section.

[0010] Preferably, the input end of the ellipsoidal sample cell is connected with the output end of the dialysate pool through a medical pipeline, and the output end of the ellipsoidal sample cell is connected with the input end of the dialysate pool through a medical pipeline.

[0011] Preferably, the laser diffusion lens group for expanding the beam section by 4 times comprises a diverging lens and a first converging lens, and the laser focusing lens group comprises a double-cemented lens and a crescent lens.

[0012] Preferably, the focal length of the diverging lens is -50 mm, and the focal length of the first converging lens is 200 mm.

[0013] Preferably, the laser working wavelength is 1064 nm, the repetition frequency is 5 Hz, and the laser pulse width is 16 ns.

[0014] Compared with the prior art, the utility model has the following beneficial effects:

[0015] The utility model discloses a ellipsoidal sample cell is placed vertically, and the input end and the output end of ellipsoidal sample cell are located at the long semi -axis of ellipsoidal sample cell, realize that the dialysate of sample cell flows into dialysate pool, and the volume of ellipsoidal sample cell is small, in order to carry out real -time accurate monitoring to the electrolyte concentration in dialysate, so as to avoid the generation of excessive hysteresis effect, reduce the accuracy of data real -time feedback. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is experimental device figure of the utility model;

[0017] Figure 2 It is ellipsoidal sample cell figure of the utility model, wherein, figure (a) is ellipsoidal sample cell front view, figure (b) is ellipsoidal sample cell side view, figure (c) is ellipsoidal sample cell rear view, figure (d) is ellipsoidal sample cell overall layout view;

[0018] Figure 3 It is spectrum diagram of the utility model, wherein, figure (a) is original spectrum diagram, figure (b) is the pretreatment spectrum diagram of ion calcium iCa;

[0019] Figure 4 It is model performance figure of the utility model, wherein, figure (a) is ion calcium iCa model performance figure, figure (b) is potassium ion model performance figure.

[0020] REFERENCE NUMERALS

[0021] 1, laser; 2, first full mirror; 3, second full mirror; 4, diverging lens; 5, first converging lens; 6, dichroic mirror; 7, doublet lens; 8, crescent lens; 9, sample cell; 10, power pump; 11, dialysate pool; 12, second converging lens; 13, optical fiber; 14, spectrometer;

[0022] 91, liquid inlet; 92, liquid outlet; 93, input end section; 94, output end section. DETAILED DESCRIPTION

[0023] To make the purpose, technical scheme and advantage of the embodiments of the present application more clear, the technical scheme in the embodiments of the present application will be described clearly and completely below with the drawings in the embodiments of the present application. Obviously, the described embodiments are some embodiments of the present application, not 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 scope of protection of the present application.

[0024] It is to be understood that the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. It is further understood that the terms "comprising," "including," "containing," and "having" and the like, when used in the specification, specify the presence of stated features, integers, steps, operations, elements, and / or components but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0025] Embodiment 1

[0026] As shown in Figure 1 The embodiment provides a device for online real-time quantitative detection of iCa in dialysate by laser-induced breakdown spectroscopy, which comprises: a flow module, the flow module comprising an ellipsoidal sample cell 9 for carrying a dialysate sample and a power pump 10 for driving the dialysate sample in the ellipsoidal sample cell 9 to flow into a dialysate cell 11;

[0027] A LIBS laser module, the LIBS laser module comprising a first total reflection mirror 2 for totally reflecting laser, a second total reflection mirror 3 for receiving reflected laser and generating high-intensity reflected laser, a laser diffusion lens group, and a laser focusing lens group, the laser diffusion lens expanding the high-intensity reflected laser, and the expanded high-intensity reflected laser being focused on the dialysate in the ellipsoidal sample cell 9 by the laser focusing lens group, and the focused high-intensity reflected laser generating plasma, specifically, in the embodiment, the laser 1 emits laser, specifically, in the embodiment, the first total reflection mirror 2 and the second total reflection mirror 3 are used to control the laser to exit, so as to prevent the laser pulse energy from fluctuating when the measurement is interrupted for a short time and then restarted;

[0028] A collection module, the dichroic mirror 6 of the collection module being arranged between the laser diffusion lens group and the laser focusing lens group, the back-propagating plasma emission light being reflected by the dichroic mirror 6 and then being converged by a second converging lens, the converged plasma emission light being collected by an optical fiber 13 and being coupled to a spectrometer 14, and the LIBS spectrum of the plasma emission light dispersed by the spectrometer 14 being collected by a detector.

[0029] As shown in Figure 1 and Figure 2 Specifically, in the embodiment, the ellipsoidal sample cell is vertically placed, the input end cross section 93 and the output end cross section 94 of the ellipsoidal sample cell 9 are located on the long semi-axis, and the input end 91 of the ellipsoidal sample cell is higher than the output end 92 of the ellipsoidal sample cell, specifically, in the embodiment, the dialysate in the sample cell flows into the dialysate cell by vertically placing the ellipsoidal sample cell and arranging the input end and the output end of the ellipsoidal sample cell on the long semi-axis of the ellipsoidal sample cell, and the ellipsoidal sample cell has a smaller surface area than a cubic sample cell and a cylindrical sample cell, is uniformly stressed, and is more firm.

[0030] Preferably, the short axis size of the ellipsoidal sample cell 9 is 30 mm, the size of the input end section 93 and the output end section 94 of the ellipsoidal sample cell is 15 mm, and the input end 91 and the output end 92 of the ellipsoidal sample cell 9 are smaller than the input end section 93 and the output end section 94. Specifically, in the present embodiment, the ellipsoidal sample cell 9 has a smaller volume than other shapes, so as to accurately monitor the electrolyte concentration in the dialysate in real time, so as to avoid excessive lag effect and reduce the accuracy of real-time data feedback.

[0031] Preferably, the input end 91 of the ellipsoidal sample cell 9 is connected to the output end of the dialysate pool 11 through a medical pipeline, and the output end 92 of the ellipsoidal sample cell 9 is connected to the input end of the dialysate pool 11 through a medical pipeline.

[0032] Preferably, the laser diffusion lens group for expanding the beam section by 4 times includes a diverging lens 4 and a first converging lens 5, and the laser focusing lens group includes a double-cemented lens 7 and a crescent lens 8.

[0033] Preferably, the focal length of the diverging lens 4 is -50 mm, and the focal length of the first converging lens 5 is 200 mm. Specifically, in the present embodiment, the combination of the diverging lens 4 (such as f=50 mm) and the first converging lens 5 (such as f=200 mm) expands the beam section diameter by 4 times.

[0034] Preferably, the laser working wavelength is 1064 nm, the repetition frequency is 5 Hz, and the laser pulse width is 16 ns.

[0035] The present embodiment provides a laser-induced breakdown spectroscopy method for online real-time quantitative detection of iCa in dialysate, which comprises the following steps:

[0036] The original spectrum is obtained according to the training sample set, the pretreated spectrum is obtained by pretreating the original spectrum, the pretreated spectrum is converted into a two-dimensional spectrum matrix, and the characteristic spectrum is obtained by feature extraction according to the two-dimensional spectrum matrix.

[0037] Preferably, the original spectrum is obtained according to the training sample set, which further comprises:

[0038] The training sample set is collected and configured, and a sample information table is prepared according to the training sample set. Specifically, in the present embodiment, dialysate samples with iCa gradient are collected and prepared, and at the same time, the potassium ion level in the dialysate also fluctuates obviously in the CRRT process in the real situation, so the potassium ion concentration gradient is also set in the sample. In order to meet the real sample situation and avoid introducing interference factors, the potassium ion concentration gradient is randomly increased during preparation, and the detection is carried out, and whether there is mutual influence between ions is observed.

[0039] Under laboratory conditions, according to the ion calcium iCa range of clinical dialysate during RCA-CRRT, real dialysate samples are collected as base liquid, and calcium chloride is used as a doping substance. When collecting real dialysate samples, samples with low calcium and potassium contents are collected as raw materials to configure experimental samples. To avoid the differences in the sample matrix caused by dilution with distilled water and to reduce the influence of total calcium changes on the detection of ion calcium iCa, dialysate with ion calcium iCa in the normal range is selected as the base liquid, and 40% trisodium citrate solution and 2 mol / L potassium chloride solution are added to simulate the real situation of RCA-CRRT, and experimental samples with different ion calcium iCa and potassium ion concentration gradients are configured. That is, two substances are randomly doped in the base liquid to prepare 54 samples with ion calcium iCa concentration gradients of 0.29-1.28 mmol / L and potassium of 3.8-8.3 mmol / L, of which 44 samples are used as a training set and 10 samples are used as a test set, and the test set has a similar data distribution as the training set.

[0040] To reduce the precipitation of samples due to placement, make them more uniform, and better meet the actual operation requirements of clinical dialysate extracorporeal circulation detection, the samples are prepared on site.

[0041] The prepared samples are calibrated using an I-STAT blood gas analyzer to obtain the measured concentration of ion calcium iCa for each sample.

[0042] A sample information table is prepared, which includes the measured concentration of ion calcium iCa for each sample. Specifically, in this embodiment, the sample information table needs to include the concentrations of ion calcium iCa and potassium ions in the training sample set.

[0043] Laser pulse-induced plasma is generated in the training sample set, and the original spectrum is obtained according to the plasma emission light. Specifically, in this embodiment, a LIBS experimental device is built, a flow module is designed, and experimental parameters are optimized to collect LIBS spectra of dialysate samples. For a single dialysate sample, a sufficient amount of LIBS spectral data is collected, and a sufficient sample flow time is collected to obtain the original spectral data set of the training sample.

[0044] The LIBS experimental device is built, including a LIBS excitation module and a collection module, an ellipsoidal sample cell, and a flow module composed of dialysate.

[0045] Please refer to Figure 1 and Figure 2As shown, the ellipsoidal sample cell 9 needs to be smooth enough to ensure that the cell is clean and free of residue from the previous sample when the sample is replaced after each experiment. The liquid inlet and outlet of the ellipsoidal sample cell 9 are designed at the long axis of the ellipsoidal cell to ensure that the liquid in the cell flows sufficiently and no turbulence occurs. The use of the ellipsoidal cell has a smaller surface area than a cubic or cylindrical cell, is uniformly stressed, and is more stable. In the experiment, the sample dialysate enters the ellipsoidal sample cell 9 from one side of the liquid inlet 91 and flows out from the other side of the liquid outlet 92, and the cell is kept substantially full of dialysate.

[0046] Preferably, the ellipsoidal sample cell 9 is connected to the power pump 10 and the dialysate cell 11 by medical tubing. The power pump 10 provides power to meet the flow rate of the sample in clinical dialysis, i.e., 4 L / h. The total volume of the dialysate 11 in the ellipsoidal sample cell 9, the dialysate cell 11, and all the pipelines is 210 mL. The experimental measurement is performed in the order of the ion calcium iCa concentration gradient from high to low, and distilled water is not used to clean the sample when the sample is replaced. In actual operation, the power of the power pump 10 is used to flow the previous sample into the dialysate cell. After being emptied, the next sample is added and allowed to circulate in the entire circuit for 10 minutes before the experiment is performed. It is estimated that the relative influence of the previous sample on the ion calcium iCa and potassium ion K of the next sample is about 0.1% and 0.02%, respectively, which can be ignored. If distilled water is used to clean the liquid pipeline when the sample is replaced, the above influence will increase.

[0047] The designed container and connecting pipeline need to ensure that the sample can be sufficiently cleaned when it is replaced after each experiment to avoid interference between samples of different concentrations. The power pump 10 should meet the flow rate of the sample in clinical human flow rate. The optimized experimental parameters should ensure that the spectral lines of ion calcium iCa 422.6 nm and potassium ion 766.5 nm are simultaneously detected. At the same time, the laser energy is optimized to reduce the energy to weaken the potassium spectral line self-absorption and increase the energy to ensure the optimal solution of the laser energy between the spectral excitation. The optimization of experimental parameters also includes but is not limited to the optimization of the laser transverse excitation of the LIBS device, the transverse collection of the spectrometer, and the optimization of the spectrometer parameter settings.

[0048] The LIBS laser module further includes a laser 1, a first total reflection mirror 2, a second total reflection mirror 3, a diverging lens 4, a first converging lens 5, a double-cemented lens 7, and a crescent lens 8. In the present example, the laser 1 generates laser light, which is reflected by the first total reflection mirror 2 to the second total reflection mirror 3 to control the laser emission. This avoids stopping the laser operation when the measurement is interrupted for a short time and causing fluctuations in the laser pulse energy when it is restarted. If the laser 1 has a stable laser pulse immediately after it is turned on, it can also not be reflected by the first total reflection mirror 2 to the second total reflection mirror 3 to control the laser emission. Reflecting by the first total reflection mirror 2 to the second total reflection mirror 3 can achieve good control of the laser emission.

[0049] The diverging lens 4, the first converging lens 5, the doublet lens 7 and the crescent lens 8 realize the function of converging and focusing the laser pulse in the liquid at a large angle and on a spot as small as possible, which can be called a laser large-angle converging and focusing module. In the present example, the beam cross-section diameter is expanded 4 times from 6 mm to 24 mm by the combination of a diverging lens 4 (such as f=50 mm) and a first converging lens 5 (such as f=200 mm), and then the laser pulse is focused in the dialysate in the ellipsoidal sample cell 9 through the doublet lens 7 and the crescent lens 8; the combination of the doublet lens 7 and the crescent lens 8 reduces the spherical aberration, shortens the focal length to 37.5 mm, increases the beam converging angle, and ensures the stable plasma excitation in the liquid. In addition, in the present example, the laser working wavelength is 1064 nm, the repetition frequency is 5 Hz, and the laser pulse width is 16 ns.

[0050] The collection module further includes a dichroic mirror 6, a second converging lens 12, an optical fiber 13 and a spectrometer 14. After the laser pulse is focused, the plasma is generated in the liquid, the plasma emission light propagates along the laser pulse incident axis in the opposite direction, is reflected by the dichroic mirror 6 and is converged on the focal point of a focusing lens 12 (f=50 mm). The optical fiber 13 is arranged at the focal point, collects the converged plasma emission light and couples it to the inlet of a spectrometer 14. The collected plasma emission light is dispersed by the spectrometer 14, and the light spectrum is collected by a detector. In the present example, a medium-band spectrometer (Mechelle 5000, Andor Technology) is selected, the spectral range is 220-900 nm, the resolution capability is λ / (Δλ)=5000, and the requirement for synchronous detection of the electrolyte elements of interest is met. The spectrometer is coupled with an enhanced CCD camera (ICCD, iStar, Andor Technology) to improve the signal-to-noise ratio. Such a selection is only illustrative and is not limited thereto. For example, a compact multi-channel spectrometer coupled with a CCD camera can also be used.

[0051] A large enough amount of LIBS spectral data should be collected as much as possible under the condition of sample flow to avoid the influence of sample non-uniformity and obtain the overall information of the sample.

[0052] In the experiment, the optimized experimental parameters are that the laser energy is 71.5 mJ, the spectrometer parameter is set to a delay of 150 ns, a gate width of 3000 ns, a gain of 4095, the spectrum is the accumulation of 20 plasma excitation signals, and 102 spectra are collected for each sample.

[0053] To avoid the disturbance of the liquid surface fluctuation caused by the incident laser pulse and the wave surface of the emitted plasma light, the laser is incident through the liquid and the contact surface of the transparent wall of the ellipsoidal sample cell, and the emitted plasma light is detected in the same axis in the opposite direction.

[0054] To avoid the disturbance of the laser ablation bubble left in the liquid to the incident laser and the wave surface of the emitted plasma light, the laser pulse incidence and the plasma emission light detection are carried out in the horizontal axis direction.

[0055] After the laser pulse is focused, the plasma is generated inside the liquid, the plasma emission light propagates in the opposite direction along the laser pulse incidence axis, and after being reflected by the dichroic mirror, it is converged near the focal point of a focusing lens (f=50 mm). An optical fiber is arranged here to collect the converged plasma emission light and couple it to the entrance of a spectrometer. The collected plasma emission light is dispersed by the spectrometer, and the spectrum is collected by the detector.

[0056] In this work, a broadband spectrometer (Mechelle 5000, Andor Technology) is selected, the spectral range is 220-900 nm, the resolution capability is λ⁄(Δλ)=5000, which meets the demand of synchronous detection of the electrolyte elements concerned. The spectrometer is coupled with an enhanced CCD camera (ICCD, iStar, Andor Technology) to improve the spectral line signal-to-noise ratio.

[0057] Preferably, the laser pulse induces the training sample set to generate plasma, and the original spectrum is obtained according to the plasma emission light, further comprising:

[0058] The laser pulse is incident on the training sample set to generate stable plasma;

[0059] The optical fiber collects the converged plasma emission light and couples the plasma emission light to the entrance of the spectrometer;

[0060] The spectrometer disperses the plasma emission light to form a spectrum;

[0061] The detector collects the spectrum to obtain an original spectrum.

[0062] Preferably, the original spectrum is pretreated to obtain a pretreated spectrum, further comprising:

[0063] The original image is removed from the baseline by wavelet transform filtering or morphological filtering to obtain a baseline-removed spectrum;

[0064] The baseline-removed spectrum is normalized by using the total area of the continuous spectrum in the 430-530 nm waveband to obtain a normalized spectrum. Specifically, in this embodiment, please refer to Figure 3(a) As shown, for each original spectrum in the spectral data set of the first training sample set, continuous spectrum normalization is performed on the original spectrum, which is intensity normalization processing using the continuous spectrum of the 430-530 nm band; the reason for adopting this method is that in a spectrum, the main element emission lines come from calcium and potassium, and the concentrations of the two elements are constantly changing, and compared with the continuous spectrum of the 430-530 nm band, which is a relatively constant quantity, it can be used as a normalization standard; the specific operation process is that, for each spectrum, the sum of the spectral intensity values corresponding to all pixels (wavelengths) of the 430-530 nm band of the spectrum is obtained to obtain an intensity sum, and the intensity normalization processing is performed on the spectral intensity values corresponding to all pixels (wavelengths) of the spectrum by using the intensity sum, to obtain a normalized spectrum;

[0065] The normalized spectrum is obtained by a moving average method to obtain a pretreated spectrum, and specifically, in the embodiment, please refer to Figure 3 (b) As shown, for each dialysate sample, the LIBS spectrum collected is obtained by a moving average method to obtain a pretreated spectrum, and the moving average method is an average processing method in which every 40 spectra are averaged to obtain one pretreated spectrum with a step of 5.

[0066] Preferably, the pretreated spectrum is subjected to feature extraction to obtain a feature spectrum, and further comprising:

[0067] The pretreated spectrum is converted into a two-dimensional spectrum matrix to obtain a two-dimensional training set, and ion calcium iCa element concentration content labels and potassium ion element concentration content labels corresponding to the two-dimensional training set spectrum matrix are formed according to the sample information table, wherein the row vectors of the two-dimensional spectrum matrix correspond to the spectral line intensities corresponding to the pixel values of the pretreated spectrum, and the number of row vectors corresponds to the number of spectra of the two-dimensional spectrum matrix. Converting the pretreated spectrum into a two-dimensional spectrum matrix facilitates data calculation;

[0068] The intensity of each spectral channel and the concentration correlation of ion calcium iCa concentration of the corresponding sample are calculated according to the two-dimensional training set, the spectral channels are sorted according to the concentration correlation from high to low to obtain a sorted training set. Specifically, in the embodiment, the two-dimensional spectrum matrix of the two-dimensional training set is calculated by feature selection to obtain the correlation of each feature with the corresponding calcium / potassium element concentration, and a SelectKBest algorithm is used to calculate a one-dimensional spectral feature correlation vector, which corresponds to the feature information of the corresponding pixel (wavelength) vector. The feature information is sorted according to the correlation from high to low, and some features with the highest correlation are selected. The feature selection calculation adopts methods such as Pearson coefficient calculation, mutual information calculation, and f-regression calculation to calculate the correlation, so as to select the top 200 features.

[0069] According to the concentration correlation, a plurality of spectral channels with high correlation are selected as spectral features in the ranking training set, and the pretreated spectrum is reduced in dimension according to the spectral features to obtain reduced dimension spectrum, and a plurality of features with the highest correlation are selected, and an integer between 100 and 300 can be generally selected.

[0070] The reduced dimension spectrum is standardized to obtain a feature spectrum, and specifically, in the embodiment, [0, 1] interval standardization can be used, and the standardization parameter is transferred to the training sample set spectrum.

[0071] The initial model is trained according to the feature spectrum and the first training sample set to obtain an optimized model, and specifically, in the embodiment, under the same clinical conditions and experimental conditions, real dialysate samples (calcium / potassium content interval) for model testing are collected and configured.

[0072] Preferably, the initial model is trained according to the feature spectrum to obtain the optimized model, and further comprising:

[0073] The initial model is trained according to the feature spectrum, the ion calcium iCa element concentration content label of the first training sample set, and the potassium ion element concentration content label to obtain an optimized model, and the optimized model parameters are saved.

[0074] The optimized model establishes a regression curve according to the ion calcium prediction value of the test sample set, and evaluates the optimized model according to the regression curve to obtain a concentration prediction model.

[0075] Preferably, the optimized model establishes a regression curve according to the ion calcium prediction value of the test sample set, and evaluates the optimized model according to the regression curve to obtain a concentration prediction model, and further comprising:

[0076] The second feature spectrum of the test sample set is tested on the optimized model to obtain a test ion calcium iCa prediction value and a test potassium ion prediction value, a regression curve is established according to the test ion calcium iCa prediction value and the test potassium ion prediction value, and the optimized model is evaluated according to the regression curve to obtain a concentration prediction model.

[0077] Preferably, the optimized model is evaluated according to the regression curve to obtain a concentration prediction model, and further comprising:

[0078] If the mean square error or the determination coefficient of the regression curve meets the set value, the optimized model parameters are saved to obtain a concentration prediction model;

[0079] If the mean square error or the determination coefficient of the regression curve does not meet the set value, the optimized model parameters are optimized, and prediction is performed again until the set value is met to obtain a concentration prediction model.

[0080] Under the same experimental conditions and experimental parameters, the LIBS spectrum of the dialysate sample of the test set is collected, the LIBS spectrum data of the test set sample is preprocessed to obtain a pretreated spectrum, the test set spectrum matrix is subjected to feature extraction to obtain a feature spectrum of the test set, the feature spectrum matrix of the test set is subjected to standardization processing to generate a feature spectrum, and the feature spectrum is input into the optimized model, please refer to Figure 4 The ion calcium iCa / potassium element prediction concentration values of the test set sample are obtained, and when the number of design samples is designed, multiple test sets need to be designed to ensure that the stable prediction performance of the model can be verified in the test process, and the prediction performance index parameters of the model are obtained, as shown in Table 1.

[0081] Table 1: Model performance parameter table obtained by the preferred column of the present method

[0082]

[0083] In a real clinical application, the experimental device is embedded in a dialysate circulating device, the LIBS spectrum of the dialysate of a patient is collected

[0084] , the above spectrum preprocessing, feature extraction dimension reduction, and spectrum standardization are used, the obtained feature spectrum is input into the concentration prediction model for prediction, and the ion calcium iCa / potassium element content of the dialysate of the patient is output respectively. The prediction performance index parameters of the above model are used to represent the accuracy performance of the determination of the two elements in the dialysate of the clinical patient.

[0085] The above only describes the preferred embodiments of the present application, and the protection scope of the present application is not limited to the above embodiments. Any technical solution under the idea of the present application belongs to the protection scope of the present application. It should be noted that, for ordinary technical personnel in the technical field, some improvements and decorations can be made without departing from the principles of the present application, and these improvements and decorations should also be considered as the protection scope of the present application.

[0086] The technical features of the above-described embodiments can be combined arbitrarily, and in order to make the description concise, all possible combinations of the technical features in the above-described embodiments are not described, however, as long as the combination of the technical features does not exist contradictory, it should be considered that it is within the scope of the present application.

[0087] It should be noted that the above embodiments can be freely combined as needed. The above only describes the preferred embodiments of the present application, and it should be noted that, for ordinary technical personnel in the technical field, some improvements and decorations can be made without departing from the principles of the present application, and these improvements and decorations should also be considered as the protection scope of the present application.

Claims

1. A device for on-line real-time quantitative detection of iCa in dialysate by laser-induced breakdown spectroscopy, characterized in that, Comprise: a flow module comprising an ellipsoidal sample cell for carrying a dialysate sample, and a power pump for driving the dialysate sample in the ellipsoidal sample cell to flow into a dialysate pool; a LIBS laser module comprising a first total reflection mirror for totally reflecting a laser, a second total reflection mirror for receiving the reflected laser and generating high-intensity reflected laser, a laser diffusion lens group for expanding the high-intensity reflected laser, and a laser focusing lens group for focusing the expanded high-intensity reflected laser on the dialysate in the ellipsoidal sample cell, and the focused high-intensity reflected laser generates plasma; a collection module, a dichroic mirror of the collection module is arranged between the laser diffusion lens group and the laser focusing lens group, back-propagating plasma emission light is reflected by the dichroic mirror and then converged by a second converging lens, the converged plasma emission light is collected by an optical fiber and coupled to a spectrometer, and a LIBS spectrum of the plasma emission light dispersed by the spectrometer is collected by a detector.

2. The device for on-line real-time quantitative detection of iCa in dialysate by laser-induced breakdown spectroscopy according to claim 1, characterized in that, The ellipsoidal sample cell is vertically placed, the input end cross section and the output end cross section of the ellipsoidal sample cell are located at the long semi-axis, and the input end of the ellipsoidal sample cell is higher than the output end of the ellipsoidal sample cell. 3.The device for online real-time quantitative detection of iCa in dialysate by laser-induced breakdown spectroscopy according to claim 2, characterized in that, The short axis of the ellipsoidal sample cell is 30 mm, the input end cross section and the output end cross section of the ellipsoidal sample cell are 15 mm, and the input end and the output end of the ellipsoidal sample cell are smaller than the input end cross section and the output end cross section.

4. The device for on-line real-time quantitative detection of iCa in dialysate by laser-induced breakdown spectroscopy according to claim 3, characterized in that, The input end of the ellipsoidal sample cell is connected to the output end of the dialysate pool through a medical pipeline, and the output end of the ellipsoidal sample cell is connected to the input end of the dialysate pool through a medical pipeline. 5.The device for online real-time quantitative detection of iCa in dialysate by laser-induced breakdown spectroscopy according to claim 4, characterized in that, The laser diffusion lens group for expanding the cross section of the light beam by 4 times comprises a diverging lens and a first converging lens, and the laser focusing lens group comprises a double-cemented lens and a crescent lens. 6.The device for online real-time quantitative detection of iCa in dialysate by laser-induced breakdown spectroscopy according to claim 5, characterized in that, The focal length of the diverging lens is -50 mm, and the focal length of the first converging lens is 200 mm.

7. The device for on-line real-time quantitative detection of iCa in dialysate by laser-induced breakdown spectroscopy according to claim 6, characterized in that, The laser working wavelength is 1064 nm, the repetition frequency is 5 Hz, and the laser pulse width is 16 ns.

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