Material photoacoustic spectrum measurement method and device

Abstract

The invention relates to a material photoacoustic spectrum measurement method and device. The method comprises the following specific steps: S1, respectively collecting photoacoustic signal data of a standard solution and a to-be-measured solution under different wavelengths; s2, processing the photoacoustic signal data through a reconstruction algorithm to generate an image, and obtaining photoacoustic signal intensity values I of the standard solution and the to-be-detected solution in each region and each scanned wavelength by using the image; and S3, performing double calibration on the obtained photoacoustic signal intensity values I of the standard solution and the solution to be detected to obtain the relative light absorption coefficient of the solution to be detected. The photoacoustic spectrum measuring method based on the photoacoustic imaging system is rapid, convenient and accurate, system operation is simplified, optical differences of biological tissues and instability of a laser system can be effectively coped with, and therefore the consistency of the photoacoustic spectrum and a real optical absorption spectrum is improved, and the measuring accuracy of the photoacoustic spectrum is improved. Therefore, accurate analysis of molecular components in biological tissues is supported.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical measurement technology, in particular to a material photoacoustic spectrum measurement method and device. BACKGROUND

[0002] Photoacoustic imaging technology is a new biomedical imaging method combining optical absorption contrast and ultrasonic spatial resolution. Its basic principle is based on the photoacoustic effect: when pulsed laser irradiates biological tissue, chromophores (such as hemoglobin, melanin, exogenous probes, etc.) in the tissue absorb light energy and produce a transient temperature rise, causing thermal-elastic expansion, thereby radiating broadband acoustic signals that can be detected by an ultrasonic transducer. Because different tissues or molecules have unique optical absorption characteristics in a specific wavelength range, photoacoustic imaging not only enables high-resolution visualization of anatomical structures, but also obtains functional and molecular information such as blood oxygen saturation, blood vessel distribution, metabolic state, and distribution of exogenous drugs or probes through multi-wavelength excitation. Further, photoacoustic spectrum technology can identify and quantify the concentration of various chromophores in the tissue by collecting and analyzing photoacoustic signals at multiple wavelengths in the same area. Thus, it has great application potential in early disease diagnosis, drug delivery process monitoring, tumor microenvironment evaluation, and personalized treatment response tracking. In particular, due to its advantages of non-invasiveness, non-radiation, high sensitivity, and deep tissue penetration, photoacoustic imaging is gradually becoming a key technology in preclinical research and translational medicine.

[0003] However, in practical applications, the existing photoacoustic spectrum measurement method still faces significant quantitative accuracy challenges, which severely restricts its accurate characterization ability at the molecular level. Traditional techniques usually use multi-wavelength pulsed lasers to irradiate the sample one by one, and reconstruct the absorption spectrum based on the measured photoacoustic signal intensity. However, this process generally ignores the influence of two key physical factors on signal consistency: one is the difference in energy stability and spot uniformity of pulsed laser at different wavelengths and irradiation directions; the other is the wavelength dependence of the optical parameters (such as scattering coefficient, refractive index, anisotropy factor) of biological tissue, which leads to uneven distribution of light flux (i.e. local light deposition energy) of different wavelengths in the tissue. The above factors directly lead to the fact that even if the same tissue has a certain absorption coefficient at different wavelengths, the generated photoacoustic signal intensity will still change due to the fluctuation of local light flux. Especially in complex biological tissues (such as tumor tissues), the heterogeneity of the structure exacerbates the uncertainty of light transmission, making the measured photoacoustic signal unable to truly reflect the intrinsic absorption characteristics of the target molecules. Therefore, directly using the original photoacoustic signal as an absorption intensity indicator for spectrum reconstruction often introduces significant deviations, making it difficult to accurately quantify chromophores.

[0004] Currently, although the prior art attempts to correct by introducing reference samples, calibration curves or optical models, these methods usually rely on additional equipment, increase the operation complexity, or require prior optical parameters, and it is difficult to realize fast, convenient and universal light flux compensation in actual imaging systems. In addition, most of the schemes fail to effectively solve the influence of the inconsistency of laser space irradiation on the comparability of multi-wavelength data, resulting in the lack of reliable normalization basis for cross-wavelength signals.

[0005] Therefore, to solve the above problems, the present application provides a new photoacoustic spectrum measurement method, which simplifies the system operation and effectively deals with the optical difference of biological tissues and the instability of laser systems, thereby improving the consistency between photoacoustic spectrum and real optical absorption spectrum to support accurate analysis of molecular components in biological tissues. SUMMARY

[0006] The present application provides a material photoacoustic spectrum measurement method and device to solve the technical problems in the prior art.

[0007] The technical solution of the present application to solve the above technical problems is as follows: A material photoacoustic spectrum measurement method, comprising the following specific steps: S1: respectively collecting photoacoustic signal data of standard solution and test solution under different wavelengths; S2: processing the photoacoustic signal data by a reconstruction algorithm to generate an image, and obtaining photoacoustic signal intensity values I of the standard solution and the test solution in each region and each scanned wavelength using the image; S3: double-calibrating the obtained photoacoustic signal intensity values I of the standard solution and the test solution to obtain the relative light absorption coefficient of the test solution.

[0008] The present application has the following beneficial effects: during the measurement process, first, the collected photoacoustic signal data of the standard solution and the test solution under different wavelengths are processed by a reconstruction algorithm to generate an image, and photoacoustic signal intensity values I of the standard solution and the test solution in each region and each scanned wavelength are obtained according to the generated image; then, the obtained photoacoustic signal intensity values I of the standard solution and the test solution are double-calibrated to obtain the relative light absorption coefficient of the test solution, which is convenient for measurement and significantly improves the consistency between photoacoustic spectrum and real optical absorption spectrum.

[0009] The present application provides a fast, convenient and accurate photoacoustic spectrum measurement method based on a photoacoustic imaging system, which simplifies the system operation and effectively deals with the optical difference of biological tissues and the instability of laser systems, thereby improving the consistency between photoacoustic spectrum and real optical absorption spectrum to support accurate analysis of molecular components in biological tissues.

[0010] On the basis of the above technical solutions, the application can be further improved as follows.

[0011] Further, the S3 comprises the following specific steps: S31: calibrating the photoacoustic signal intensity value I of the obtained standard solution and the to-be-tested solution once to obtain the photoacoustic signal intensity I' of the standard solution and the to-be-tested solution; S32: recalibrating the photoacoustic signal intensity I' of the obtained standard solution and the to-be-tested solution to obtain the photoacoustic signal intensity I'' of the standard solution and the to-be-tested solution, and the finally obtained I'' represents the relative light absorption coefficient of the to-be-tested solution.

[0012] The beneficial effect of the above further solution is that the method is simple and reasonable in design, the photoacoustic signal intensity value I of the collected standard solution and the to-be-tested solution can be double calibrated to obtain the photoacoustic signal intensity I'', the finally obtained I'' represents the relative light absorption coefficient of the to-be-tested solution, the result can reflect the real optical absorption characteristics of the to-be-tested solution, and the method has cross-system comparability.

[0013] Further, the S31 comprises the following specific steps: dividing the photoacoustic signal intensity of each position of the to-be-tested solution module by the photoacoustic signal intensity of the same position in the standard solution module to obtain the photoacoustic signal intensity after the first calibration, that is, , .

[0014] The beneficial effect of the above further solution is that the method is simple and reasonable in design, the photoacoustic signal intensity I' of the to-be-tested solution after the first calibration can be obtained through the first calibration, the calibration is convenient and efficient, which is conducive to realizing the normalization of the laser energy and eliminating the influence of the non-uniform laser energy in different directions.

[0015] Further, the S32 comprises the following specific steps: dividing the photoacoustic signal intensity of the control solution after the first calibration by the known light absorption coefficient of the standard solution to obtain the system calibration coefficient K, that is, , dividing the photoacoustic signal intensity of the to-be-tested solution after the first calibration by the system calibration coefficient K to obtain the photoacoustic signal intensity of the to-be-tested solution after the second calibration , that is, .

[0016] The beneficial effect of the further scheme is that the method is simple and reasonable in design, and the photoacoustic signal intensity I'' of the secondary calibrated solution can be obtained through secondary calibration, which is convenient and efficient and further improves the consistency between the photoacoustic spectrum and the real optical absorption spectrum.

[0017] Further, the S2 comprises the following specific steps: calculating the difference between the maximum value and the minimum value of all pixel points in each region of the generated image, and recording the difference as the photoacoustic signal intensity of the solution in the capillary in the region; and processing each frame of image in the same way to obtain the photoacoustic signal intensity values I of the standard solution and the solution to be measured at each region and each scanned wavelength.

[0018] The beneficial effect of the further scheme is that the method is simple and reasonable in design, and the photoacoustic signal intensity of the solution in the capillary in each region can be obtained by calculating the difference between the maximum value and the minimum value of all pixel points in each region of the generated image.

[0019] Further, the S3 further comprises S4: drawing a photoacoustic spectrum curve with the laser wavelength as the horizontal coordinate and the relative light absorption coefficient as the vertical coordinate.

[0020] The beneficial effect of the further scheme is that the method is simple and reasonable in design, and after completing the double calibration, the photoacoustic spectrum curve is drawn with the laser wavelength as the horizontal coordinate and the relative light absorption coefficient as the vertical coordinate, the result can reflect the real optical absorption characteristics of the solution to be measured, and has cross-system comparability.

[0021] Further, the S1 further comprises S0: filling the standard solution in the standard channel in the calibration solution module, and filling the control solution in one of the solution to be measured channels in the solution to be measured module, and filling the solution to be measured in the remaining solution to be measured channels in the solution to be measured module.

[0022] The beneficial effect of the further scheme is that the method is simple and reasonable in design, and the standard solution module and the solution to be measured module are prepared in advance, which facilitates the subsequent rapid measurement and improves the measurement efficiency.

[0023] Further, the standard solution and the control solution in the S0 are both CuSO4 solutions with the same concentration, and the concentration of the CuSO4 solution is 0.1 mol / L-0.5 mol / L.

[0024] The beneficial effect of the further scheme is that the method is simple and reasonable in design, and the standard solution and the control solution are selected as 0.1 mol / L-0.5 mol / L CuSO4 solution, which is reasonable, and the CuSO4 in this concentration range can provide a stable photoacoustic signal reference and further improve the consistency between the photoacoustic spectrum and the real optical absorption spectrum.

[0025] Further, the standard channel and the plurality of to-be-measured channels in the S0 are capillary tubes.

[0026] The beneficial effect of the above further scheme is that the standard channel and the to-be-measured channel adopt capillary tubes, which can accommodate standard solution and to-be-measured solution, and is beneficial to the measurement of material components, and has high accuracy.

[0027] The present application also relates to a device for the material photoacoustic spectroscopy measurement method as described above.

[0028] The beneficial effect of the above further scheme is that the present application provides a material photoacoustic spectroscopy measurement device, which is simple to operate, can effectively cope with the optical difference of biological tissues and the instability of a laser system, thereby improving the consistency of photoacoustic spectroscopy and real optical absorption spectrum, supporting accurate analysis of molecular components in biological tissues, and measuring quickly, conveniently and accurately. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 The flowchart of the measurement method in the present application; Figure 2 The photoacoustic spectroscopy curve in the present application; Figure 3 The photoacoustic image schematic diagram in the present application; Figure 4 The overall structure schematic diagram of the first embodiment of the measurement device in the present application; Figure 5 The overall structure schematic of the second embodiment of the measurement device in the present application; Figure 6 The partial structure schematic diagram of the measurement device in the present application; Figure 7 The structure schematic diagram of the mounting plate in the present application; Figure 8 The structure schematic diagram of the magnet block in the present application.

[0030] In the drawings, the component list represented by each number is as follows: 1, mounting plate; 2, connecting frame; 3, circular hole; 4, capillary tube; 5, rectangular slot; 6, through hole; 7, magnet block; 8, bolt. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the 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 are within the scope of protection of the present application.

[0032] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0033] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this technology based on the specific circumstances.

[0034] In the description of this application, spatial relation terms such as "below," "under," "below," "below," "above," "over," etc., are used herein to describe the relationship between one element or feature shown in the figures and other elements or features. It should be understood that, in addition to the orientation shown in the figures, spatial relation terms also include different orientations of the device in use and operation. For example, if the device in the figures is flipped, an element or feature described as "below" or "under" or "below" of other elements or features will be oriented "above" other elements or features. Therefore, the exemplary terms "below" and "under" can include both upper and lower orientations. Furthermore, the device may also include other orientations (e.g., rotated 90 degrees or other orientations), and the spatial descriptive terms used herein are interpreted accordingly.

[0035] In the description of this application, the term "for example" is used to mean "used as an example, illustration, or description." Any embodiment described as "for example" in this application is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to make and use the invention. Details are set forth in the following description for purposes of explanation. It should be understood that those skilled in the art will recognize that the invention can be made without using these specific details. In other instances, well-known structures and processes will not be described in detail to avoid obscuring the description of the invention with unnecessary detail. Therefore, the invention is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed in this application.

[0036] Example 1 like Figures 1 to 3As shown, the embodiment provides a material photoacoustic spectrum measurement method, comprising the following specific steps: S1: respectively collecting photoacoustic signal data of the standard solution and the to-be-measured solution under different wavelengths; S2: processing the photoacoustic signal data by a reconstruction algorithm to generate an image, and obtaining photoacoustic signal intensity values I of the standard solution and the to-be-measured solution in each region and each scanned wavelength by using the image; S3: double-calibrating the photoacoustic signal intensity values I of the standard solution and the to-be-measured solution to obtain the relative light absorption coefficient of the to-be-measured solution.

[0037] During the measurement, first, the photoacoustic signal data of the standard solution and the to-be-measured solution under different wavelengths are processed by a reconstruction algorithm, and an image is generated, and photoacoustic signal intensity values I of the standard solution and the to-be-measured solution in each region and each scanned wavelength are obtained according to the generated image; then, the photoacoustic signal intensity values I of the standard solution and the to-be-measured solution are double-calibrated to obtain the relative light absorption coefficient of the to-be-measured solution, which is convenient to measure and significantly improves the consistency between the photoacoustic spectrum and the real optical absorption spectrum.

[0038] Based on the above scheme, the specific steps of collecting the photoacoustic signal data of the standard solution and the to-be-measured solution under different wavelengths in S1 are as follows: The assembled standard solution and to-be-measured solution module is placed in the photoacoustic imaging system, and photoacoustic imaging scanning is performed under the condition of filling water medium.

[0039] During the data collection process, first, the photoacoustic imaging system is controlled to move the standard solution module into the measurement plane to ensure that the sampling region covers all capillary signals, and to perform multi-wavelength scanning to obtain standard solution photoacoustic signal data.

[0040] After completion, the photoacoustic imaging system is controlled to move the to-be-measured solution module into the measurement plane, and multi-wavelength photoacoustic data is collected in the same way; if there are multiple to-be-measured solution modules, the photoacoustic imaging system is controlled to sequentially scan each to-be-measured solution module in the same way to collect multi-wavelength photoacoustic signal raw data.

[0041] Based on the above scheme, the specific operation of how the standard solution module and the to-be-measured solution module are sent into or out of the photoacoustic imaging system is prior art, which will not be described here.

[0042] The embodiment provides a fast, convenient and accurate photoacoustic spectrum measurement method based on a photoacoustic imaging system, which simplifies system operation and effectively deals with the optical difference of biological tissues and the instability of the laser system, thereby improving the consistency between the photoacoustic spectrum and the real optical absorption spectrum to support accurate analysis of molecular components in biological tissues.

[0043] Embodiment 2 In this embodiment, on the basis of embodiment 1, the S3 comprises the following specific steps: S31: calibrating the photoacoustic signal intensity value I of the obtained standard solution and the to-be-tested solution once to obtain the photoacoustic signal intensity I' of the standard solution and the to-be-tested solution; S32: calibrating the photoacoustic signal intensity I' of the obtained standard solution and the to-be-tested solution again to obtain the photoacoustic signal intensity I'' of the standard solution and the to-be-tested solution, and the finally obtained I'' represents the relative light absorption coefficient of the to-be-tested solution.

[0044] The method is simple and reasonable, the photoacoustic signal intensity value I of the collected standard solution and the to-be-tested solution can be calibrated twice to obtain the photoacoustic signal intensity I'', and the finally obtained I'' represents the relative light absorption coefficient of the to-be-tested solution, the result can reflect the real optical absorption characteristics of the to-be-tested solution, and has cross-system comparability.

[0045] Embodiment 3 In this embodiment, on the basis of embodiment 2, the S31 comprises the following specific steps: dividing the photoacoustic signal intensity of each position of the to-be-tested solution module by the photoacoustic signal intensity of the same position in the standard solution module to obtain the photoacoustic signal intensity after the first calibration, that is, , .

[0046] The method is simple and reasonable, and the photoacoustic signal intensity I' of the to-be-tested solution after the first calibration can be obtained through the first calibration, which is convenient and efficient, and is conducive to realizing the normalization of laser energy and eliminating the influence of uneven laser energy in different directions.

[0047] Embodiment 4 In this embodiment, on the basis of any one of embodiments 2 to 3, the S32 comprises the following specific steps: dividing the photoacoustic signal intensity of the control solution after the first calibration by the known light absorption coefficient of the standard solution to obtain the system calibration coefficient K, that is , dividing the photoacoustic signal intensity of the to-be-tested solution after the first calibration by the system calibration coefficient K to obtain the photoacoustic signal intensity of the to-be-tested solution after the second calibration , that is .

[0048] The method is simple, reasonable in design, and can obtain the photoacoustic signal intensity I'' of the to-be-measured solution after secondary calibration through secondary calibration, is convenient and efficient, and further improves the consistency between the photoacoustic spectrum and the real optical absorption spectrum.

[0049] Embodiment 5 On the basis of the above embodiments, in this embodiment, the S2 comprises the following specific steps: calculating the difference between the maximum value and the minimum value of all pixel points in each region of the generated image, and recording it as the photoacoustic signal intensity of the solution in the capillary of the region; and the standard solution and the to-be-measured solution are processed in the same way to obtain the photoacoustic signal intensity value I of the solution in each region and each scanned wavelength.

[0050] The method is simple, reasonable in design, and can obtain the photoacoustic signal intensity of the solution in the capillary of the region by calculating the difference between the maximum value and the minimum value of all pixel points in each region of the generated image.

[0051] Based on the above scheme, the collected data is generated into an image through a reconstruction algorithm (such as the UBP algorithm), and the signal of the solution in each channel capillary in the standard module and the to-be-measured module can be displayed in the reconstructed image (a single-frame image is shown as Figure 3 ).

[0052] In addition, the full name of the above-mentioned UBP algorithm is‌ Universal Back-Projection.

[0053] Embodiment 6 On the basis of the above embodiments, in this embodiment, the S3 further comprises S4: taking the laser wavelength as the horizontal coordinate and the relative light absorption coefficient as the vertical coordinate, drawing the photoacoustic spectrum curve (see Figure 2 ).

[0054] The method is simple, reasonable in design, and can obtain the photoacoustic signal intensity of the solution in the capillary of the region by calculating the difference between the maximum value and the minimum value of all pixel points in each region of the generated image.

[0055] Based on the above scheme, the three curves in the attached Figure 2 are the measurement results of three different materials, the horizontal coordinate is the laser wavelength (unit: nm), and the vertical coordinate is the relative light absorption coefficient.

[0056] Embodiment 7 On the basis of the above embodiments, in this embodiment, the S1 further comprises S0: filling the standard solution in the standard channel in the calibration solution module, and filling the control solution in one to-be-measured channel in the to-be-measured solution module, and filling the to-be-measured solution in the remaining to-be-measured channels in the to-be-measured solution module.

[0057] The method is simple, the design is reasonable, the standard solution module and the to-be-measured solution module are prepared in advance, subsequent measurement can be quickly performed, and measurement efficiency is high.

[0058] Based on the above scheme, the standard solution module is internally provided with a standard solution with the same concentration, the standard solution has the characteristics of laser irradiation resistance, non-decomposition, non-deterioration, and no light bleaching, and can be repeatedly used.

[0059] In addition, the standard solution is replaced every 3-6 months under normal conditions.

[0060] Example 8 In this embodiment, the standard solution and the control solution in the S0 are CuSO4 solutions with the same concentration, and the concentration of the CuSO4 solution is 0.1 mol / L-0.5 mol / L.

[0061] The method is simple, and it is reasonable to select the 0.1 mol / L-0.5 mol / L CuSO4 solution as the standard solution and the control solution. The CuSO4 in the concentration range can provide a stable photoacoustic signal reference, and can further improve the consistency between the photoacoustic spectrum and the real optical absorption spectrum.

[0062] Preferably, in the above S0, the standard solution and the control solution are respectively 0.2 mol / L CuSO4 solutions.

[0063] Example 9 On the basis of any one of the embodiments 7 to 8, in this embodiment, the standard channel and the plurality of to-be-measured channels in the S0 are respectively capillary tubes.

[0064] The scheme is reasonable to use capillary tubes as the standard channel and the to-be-measured channel, which can accommodate the standard solution and the to-be-measured solution, and is beneficial to the measurement of material components, and has high accuracy.

[0065] Example 10 On the basis of the above embodiments, as shown in Figure 4 and Figure 8 The embodiment further provides a device for the material photoacoustic spectrum measurement method.

[0066] The material photoacoustic spectrum measurement device provided in the embodiment comprises a photoacoustic imaging system, a standard solution module, and a to-be-measured solution module, and the specific structures of the parts are as follows: (1) The photoacoustic imaging system is the prior art, and the specific structure and principle will not be described here.

[0067] (2) The standard solution module and the to-be-tested solution module have the same structure, both of which comprise two mounting plates 1, the two mounting plates 1 are oppositely arranged, and the centers of the two mounting plates 1 are connected by a connecting frame 2.

[0068] Preferably, in the embodiment, the connecting frame 2 has a rectangular cross section.

[0069] Alternatively, the connecting frame 2 can also have a circular cross section.

[0070] Preferably, the two mounting plates 1 are both circular plates, a plurality of pairs of through circular holes 3 are oppositely arranged on the two circular plates, and the plurality of circular holes 3 on each of the circular plates are uniformly distributed along the circumference of the circular plate. Each pair of circular holes 3 are communicated by a capillary tube 4.

[0071] Moreover, the number of pairs of circular holes 3 arranged on the two mounting plates 1 can be designed according to actual conditions, which is not limited herein.

[0072] In addition, the centers of the sides of the two mounting plates 1 close to each other are oppositely provided with rectangular grooves 5, and the two ends of the connecting frame 2 extend into the two rectangular grooves 5, respectively. Moreover, the sides of the two mounting plates 1 away from each other are oppositely provided with through holes 6 communicated with the two rectangular grooves 5, respectively. During assembly, the bolt 8 is screwed with one end of the connecting frame 2 after passing through the through hole 6 and the rectangular groove 5, and the two ends of the connecting frame 2 are respectively provided with threaded holes.

[0073] During assembly, one standard solution module is used, and one or more to-be-tested solution modules can be used. When multiple to-be-tested solution modules are used, the multiple to-be-tested solution modules and the standard solution module are sequentially stacked from top to bottom, and the position of the standard solution module is not limited.

[0074] In addition, the circular holes in the adjacent modules correspond to each other and are communicated with each other.

[0075] Preferably, in the embodiment, during assembly, the adjacent two modules can be connected by magnets. Specifically, the two mounting plates 1 corresponding to the two modules are attached to each other, and the two through holes 6 corresponding to the two mounting plates 1 are respectively provided with magnet blocks 7, and the two magnet blocks 7 are attracted to each other to connect the two modules.

[0076] In addition, the center of each magnet block 7 is provided with a through hole for the bolt to pass through.

[0077] The embodiment provides a material photoacoustic spectrum measurement device, which is simple to operate, can effectively cope with the optical difference of biological tissues and the instability of a laser system, thereby improving the consistency of photoacoustic spectrum and real optical absorption spectrum, supporting accurate analysis of molecular components in biological tissues, and measuring quickly, conveniently and accurately.

[0078] The material photoacoustic spectrum measurement method provided by the application comprises the following specific steps: S0: filling a standard solution in a standard channel in a calibration solution module, and filling a control solution in one of the test channels in a test solution module, while filling test solutions in the remaining test channels in the test solution module; S1: collecting photoacoustic signal data of the standard solution and the test solution at different wavelengths respectively; S2: processing the photoacoustic signal data by a reconstruction algorithm to generate images, and calculating the difference between the maximum value and the minimum value of all pixel points in each region of the generated images, and recording the difference as the photoacoustic signal intensity of the solution in the capillary in the region; each frame of image is processed in the same way to obtain the photoacoustic signal intensity value I of the standard solution and the test solution at each region and each scanned wavelength; The double calibration in S3 comprises the following specific steps: (1) One-time calibration (spot uniformity correction): dividing the photoacoustic signal intensity of each position of the test solution module by the photoacoustic signal intensity of the same position in the standard solution module to obtain the photoacoustic signal intensity after one-time calibration, that is, , , (2) Two-time calibration (relative quantitative correction): dividing the photoacoustic signal intensity of the control solution after one-time calibration by the known optical absorption coefficient of the standard solution to obtain the system calibration coefficient K, that is, , dividing the photoacoustic signal intensity of the test solution after one-time calibration by the system calibration coefficient K to obtain the photoacoustic signal intensity of the test solution after two-time calibration , that is, , S4: drawing a photoacoustic spectrum curve with the laser wavelength as the abscissa and the relative optical absorption coefficient as the ordinate.

[0079] The application provides a fast, convenient and accurate photoacoustic spectrum measurement method based on a photoacoustic imaging system, and relates to the design and implementation of related algorithms, hardware devices and scanning control software. The method significantly improves the consistency between the photoacoustic spectrum and the real optical absorption spectrum through the combined measurement of the standard solution and the test solution and two-stage calibration.

[0080] Furthermore, the novel photoacoustic spectroscopy measurement method proposed in this invention simplifies system operation and effectively addresses the optical differences in biological tissues and the instability of laser systems, thereby improving the consistency between photoacoustic spectra and true optical absorption spectra to support the accurate analysis of molecular components in biological tissues.

[0081] Compared with the prior art, the present invention has the following advantages: 1. This invention provides a convenient photoacoustic spectral measurement method that can be implemented in existing photoacoustic imaging systems without the need for complex additional equipment; 2. This invention achieves unified normalization and quantification of cross-wavelength signals through modular design and standard solution comparison; 3. This invention improves the consistency between photoacoustic spectrum and true light absorption spectrum, significantly enhancing the reliability of its application in functional imaging, disease diagnosis, and drug monitoring. 4. The method provided by this invention has good versatility and scalability, and is suitable for quantitative research on various biological tissues and under different experimental conditions; 5. In this invention, the coaxially fixed standard solution module and test solution module facilitate the installation and disassembly of the sample mold. Furthermore, during scanning, only the sample mold needs to be moved up and down to ensure that multi-wavelength photoacoustic signals are acquired from all modules while maintaining a constant light intensity distribution.

[0082] While embodiments or examples of this disclosure have been described with reference to the accompanying drawings, it should be understood that the above embodiments are merely exemplary embodiments or examples, and the scope of the invention is not limited by these embodiments or examples, but only by the granted claims and their equivalents. Various elements in the embodiments or examples may be omitted or replaced by their equivalents. Furthermore, the steps may be performed in a different order than that described in this disclosure. Further, various elements in the embodiments or examples may be combined in various ways. Importantly, as the technology evolves, many elements described herein can be replaced by equivalents that appear after this disclosure.

Claims

1. A method for measuring photoacoustic spectroscopy of materials, characterized in that, The specific steps include the following: S1: Collect photoacoustic signal data of the standard solution and the test solution at different wavelengths respectively; S2: The above photoacoustic signal data is processed by the reconstruction algorithm to generate an image, and the photoacoustic signal intensity value I of the standard solution and the test solution in each region and at each scanned wavelength is obtained using the above image; S3: Perform dual calibration on the photoacoustic signal intensity values ​​I of the standard solution and the test solution obtained above to obtain the relative light absorption coefficient of the test solution.

2. The material photoacoustic spectroscopy measurement method according to claim 1, characterized in that, S3 includes the following specific steps: S31: Perform a calibration on the photoacoustic signal intensity values ​​I of the standard solution and the test solution obtained above to obtain the photoacoustic signal intensity I' of the standard solution and the test solution; S32: Recalibrate the photoacoustic signal intensity I' of the standard solution and the test solution obtained above to obtain the photoacoustic signal intensity I'' of the standard solution and the test solution. The final I'' represents the relative light absorption coefficient of the test solution.

3. The material photoacoustic spectroscopy measurement method according to claim 2, characterized in that, S31 includes the following specific steps: dividing the photoacoustic signal intensity at each position of the test solution module by the photoacoustic signal intensity at the same position in the standard solution module to obtain the photoacoustic signal intensity after one calibration, i.e. ， 。 4. The material photoacoustic spectroscopy measurement method according to claim 2, characterized in that, S32 includes the following specific steps: Increasing the photoacoustic signal intensity of the control solution after one calibration. Divide by the known light absorption coefficient of the standard solution To obtain the system calibration coefficient K, i.e. ， The photoacoustic signal intensity of the test solution after one calibration Divide by the system calibration coefficient K to obtain the photoacoustic signal intensity of the test solution after secondary calibration. ,Right now 。 5. The method for measuring photoacoustic spectrometry of materials according to any one of claims 1-4, characterized in that, The S2 includes the following specific steps: calculating the difference between the maximum and minimum values ​​of all pixels in each region of the generated image, and recording it as the photoacoustic signal intensity of the solution in the capillary of that region; processing each frame of the image in the same way to obtain the photoacoustic signal intensity values ​​I of the standard solution and the test solution in each region and at each scanned wavelength.

6. The method for measuring photoacoustic spectrometry of materials according to any one of claims 1-4, characterized in that, S3 is followed by S4: plotting a photoacoustic spectrum curve with the laser wavelength as the abscissa and the relative light absorption coefficient as the ordinate.

7. The method for measuring photoacoustic spectrometry of materials according to any one of claims 1-4, characterized in that, Before S1, S0 is also included: filling a standard solution in the standard channel of the calibration solution module, filling a control solution in one test channel of the test solution module, and filling the remaining test channels of the test solution module with test solutions.

8. The material photoacoustic spectroscopy measurement method according to claim 7, characterized in that, The standard solution and control solution in S0 are both CuSO4 solutions with the same concentration, which is 0.1 mol / L to 0.5 mol / L.

9. The material photoacoustic spectroscopy measuring device according to claim 7, characterized in that, The standard channel and multiple channels to be tested in S0 are capillaries.

10. An apparatus for a material photoacoustic spectroscopy measurement method as described in any one of claims 1-9.

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