Method and device for determining virtual scale of lung counter and storage medium

Abstract

The invention relates to a lung counter virtual scale determination method and device and a storage medium, and the method comprises the steps: obtaining a simulated lung digital model which comprises a lung, a soft tissue at the outer side of the lung, and a hard bone at the outer side of the lung; forming a radioactive source point location on the lung based on the simulated lung digital model; constructing a detector model through a virtual representation method; placing the detector model in a space where the simulated lung digital model is located; the radioactive source point location of the simulated lung digital model is detected based on the detector model, the detection efficiency corresponding to the detector model is determined, and the detection efficiency is used for indicating the virtual scale of a lung counter. The technical effects that radioactive sources can be evenly placed in the lung, and the cost is reduced by using the virtual model are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of radioactive measuring instrument calibration, and in particular to a method, a device and a storage medium for determining a virtual scale of a lung counter. Background Art

[0002] In occupational exposure practices such as nuclear fuel cycle, radioisotope production and nuclear facility decommissioning, in addition to the external radiation dose at work, internal contamination often occurs, resulting in internal radiation dose. The internal radiation dose is an important part of the personal dose. Internal radiation in vivo monitoring technology is an important, fast and simple means of evaluating internal radiation dose, providing basic data for the management of personal radiation protection doses, the evaluation of radiation health hazards and the medical treatment of overexposure.

[0003] The lung counter is a direct monitoring device for the internal radiation dose of radionuclides inhaled by the human body. It has the advantages of being direct, fast, sensitive, with small errors and easy to use, and is therefore widely used in the production, storage, use, management, decommissioning and nuclear accident handling of radioactive sources. During the measurement process of the lung technical instrument, its measurement scale (i.e. the ratio of the activity of the measured radionuclide to the actual activity of the nuclide deposited in the lung) is of great significance in the subsequent calculation of internal radiation dose.

[0004] In the prior art, the method for determining the measurement scale of a lung counter is generally to make a lung model, conduct experiments based on the lung model, and obtain the measurement scale. Since the radiation source in the lung model is difficult to place evenly and the lung model is expensive to make, the prior art has the disadvantages of high experimental conditions and high experimental costs.

[0005] The above problems need to be solved urgently. Summary of the invention

[0006] The invention discloses a method, a device and a storage medium for determining a virtual scale of a lung counter, aiming to solve the technical problems existing in the prior art.

[0007] The present invention adopts the following technical solutions:

[0008] On the one hand, the present invention provides a method for determining the virtual scale of a lung counter, which includes: obtaining a simulated lung digital model, wherein the simulated lung digital model includes lungs, soft tissue outside the lungs, and hard bones outside the lungs; based on the simulated lung digital model, forming a radiation source point in the lungs; constructing a detector model through a virtual characterization method; placing the detector model in the space where the simulated lung digital model is located; based on the detector model, detecting the radiation source point of the simulated lung digital model, and determining the detection efficiency corresponding to the detector model, wherein the detection efficiency is used to indicate the virtual scale of the lung counter.

[0009] Optionally, the method includes: performing a CT scan on the simulated lung model to obtain a CT image, wherein the CT image includes a plurality of different grayscale values; determining the length, width, and height of the lung voxels of the simulated lung model, the length, width, and height of the soft tissue voxels on the outside of the lungs, and the length, width, and height of the hard bone voxels on the outside of the lungs based on the grayscale values ​​in the CT image; and constructing the simulated lung digital model based on the length, width, and height of the lung voxels of the simulated lung model, the length, width, and height of the soft tissue voxels on the outside of the lungs, and the length, width, and height of the hard bone voxels on the outside of the lungs.

[0010] Optionally, the simulated lung digital model is constructed based on the lung voxel length, width and height of the simulated lung model, the soft tissue voxel length, width and height of the lung outside, and the hard bone voxel length, width and height of the lung outside, including: determining the lung two-dimensional matrix text based on the lung voxel length, width and height of the simulated lung model; determining the soft tissue two-dimensional matrix text based on the soft tissue voxel length, width and height of the lung outside; determining the hard bone two-dimensional matrix text based on the hard bone voxel length, width and height of the lung outside; traversing and inputting the lung two-dimensional matrix text in a loop to obtain the lung of the simulated lung digital model; traversing and inputting the soft tissue two-dimensional matrix text in a loop to obtain the soft tissue of the simulated lung digital model; traversing and inputting the hard bone two-dimensional matrix text in a loop to obtain the hard bone of the simulated lung digital model; constructing the simulated lung digital model based on the lung, the soft tissue and the hard bone.

[0011] Optionally, forming radiation source points in the lungs based on the simulated digital model of the lungs includes: constructing an enclosing sphere based on the lungs of the simulated digital model of the lungs; uniformly and randomly placing a plurality of initial radiation source points in the enclosing sphere; emitting rays with the plurality of initial radiation source points as origins, respectively, and retaining initial radiation source points corresponding to odd numbers of intersections of the rays with the lungs; traversing a plurality of rays emitted with the plurality of initial radiation source points as origins, and stopping the traversal when the number of retained initial radiation source points exceeds a preset number; and determining radiation source points to be formed in the lungs based on the retained initial radiation source points.

[0012] Optionally, a detector model is constructed by a virtual characterization method, including: determining the dead layer thickness of the detector model; building the dead layer of the detector model based on the dead layer thickness; and sequentially building an insulating layer, an aluminum bracket, an incident window and an aluminum shell of the detector model outside the dead layer.

[0013] Optionally, determining the dead layer thickness of the detector model includes: presetting an initial dead layer thickness; calculating an initial full-energy peak efficiency of the detector model based on the initial dead layer thickness; cyclically adjusting the initial dead layer thickness based on a comparison between the initial full-energy peak efficiency and a preset efficiency value to obtain multiple full-energy peak efficiencies; when the error between the multiple full-energy peak efficiencies and the preset efficiency value is less than a preset error, stopping the cyclic adjustment to obtain the dead layer thickness of the detector model.

[0014] Optionally, placing the detector model in the space where the simulated lung digital model is located includes: constructing a simulation coordinate system of the simulated lung digital model; and placing the detector model in the space where the simulated lung digital model is located based on the simulation coordinate system.

[0015] Optionally, constructing a simulation coordinate system of the simulated lung digital model includes: determining the length, width and height of the first row of hard bone voxels in the hard bone two-dimensional matrix text; determining the midpoint of the hard bone based on the length, width and height of the first row of hard bone voxels; taking the midpoint of the hard bone as the origin, determining the direction from the front chest to the back in the simulated lung digital model as the positive direction of the X-axis; taking the midpoint of the hard bone as the origin, determining the direction from the top of the head to the body in the simulated lung digital model as the positive direction of the Z-axis; taking the midpoint of the hard bone as the origin, determining the direction from the right arm to the left arm in the simulated lung digital model as the positive direction of the Y-axis.

[0016] Optionally, the detection of the radiation source points of the simulated lung digital model based on the detector model to determine the detection efficiency corresponding to the detector model includes: the detector model acquiring the rays emitted by the radiation source points of the simulated lung digital model; the detector model determining the radiation amount of the radiation source based on the rays; the detector model determining the fluence rate of the radiation source based on the rays; determining the number of particles measured by the detector model based on the radiation amount and the fluence rate; and determining the detection efficiency corresponding to the detector model based on the number of particles measured by the detector model and the actual total number of particles in the radiation source.

[0017] Optionally, the detector model determines the radiation amount of the radiation source based on the rays, including: determining the radiation source energy based on the rays; determining the volume and dead layer thickness of the detector model; and integrating based on the radiation source energy, the volume and the dead layer thickness to obtain the radiation amount of the radiation source.

[0018] Optionally, the detector model determines the fluence rate of the radiation source based on the ray, including: obtaining the number of radiation source points; determining the point kernel function from the radiation source point to a preset position based on the ray and the radiation source energy; determining the activity of the radiation source based on the ray; determining the fluence rate of the radiation source based on the number of radiation source points, the point kernel function and the activity of the radiation source.

[0019] According to another aspect of an embodiment of the present invention, a device for determining a virtual scale of a lung counter is provided, comprising: an acquisition module for acquiring a simulated lung digital model, wherein the simulated lung digital model comprises lungs, soft tissue outside the lungs and hard bones outside the lungs; a radiation source point module for forming radiation source points in the lungs based on the simulated lung digital model; a detector model module for constructing a detector model through a virtual characterization method; a placement module for placing the detector model in the space where the simulated lung digital model is located; a detection efficiency determination module for detecting the radiation source points of the simulated lung digital model based on the detector model, and determining the detection efficiency corresponding to the detector model, wherein the detection efficiency is used to indicate the virtual scale of the lung counter.

[0020] According to another aspect of an embodiment of the present invention, a non-volatile storage medium is provided, wherein the non-volatile storage medium stores a plurality of instructions, wherein the instructions are suitable for being loaded by a processor and executing any one of the methods for determining a virtual scale of a lung counter.

[0021] According to another aspect of an embodiment of the present invention, there is further provided a computer program product, comprising a computer program, wherein when the computer program is executed by a processor, the steps of any one of the methods for determining a virtual scale of a lung counter are implemented.

[0022] The technical solution adopted by the present invention can achieve at least one of the following beneficial effects:

[0023] In an embodiment of the present invention, a simulated lung digital model is obtained, wherein the simulated lung digital model includes lungs, soft tissue outside the lungs, and hard bones outside the lungs; based on the simulated lung digital model, a radiation source point is formed in the lungs; a detector model is constructed by a virtual characterization method; the detector model is placed in the space where the simulated lung digital model is located; based on the detector model, the radiation source point of the simulated lung digital model is detected, and the detection efficiency corresponding to the detector model is determined, wherein the detection efficiency is used to indicate the virtual scale of the lung counter. The purpose of setting a virtual lung simulation digital model and a detector model, and virtually constructing a simulation test is achieved, thereby achieving the technical effect of evenly placing the radiation source and using the virtual model to reduce the cost, thereby solving the technical problem that the radiation source in the lung model is difficult to be evenly placed and the lung model is expensive to make, resulting in high experimental conditions and high experimental costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments, which constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions explain the present invention and do not constitute improper limitations on the present invention. In the drawings:

[0025] Figure 1 is a flow chart of a method for determining a virtual scale of a lung counter in embodiment 1 of the present invention;

[0026] Figure 2 It is a technical route block diagram of a method for determining a virtual scale of a lung counter in embodiment 1 of the present invention;

[0027] Figure 3 It is a diagram of a simulated lung digital model in a method for determining a virtual scale of a lung counter in embodiment 1 of the present invention;

[0028] Figure 4 It is a detector model diagram in a method for determining a virtual scale of a lung counter in embodiment 1 of the present invention;

[0029] Figure 5 is a diagram of a simulation coordinate system in a method for determining a virtual scale of a lung counter in embodiment 1 of the present invention;

[0030] Figure 6 It is a structural schematic diagram of a device for determining a virtual scale of a lung counter in Example 2 of the present invention. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention and the corresponding drawings. In the description of the present invention, it should be noted that the term "or" is usually used in the sense of including "and / or", unless the content clearly indicates otherwise.

[0032] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or a magnetic connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be a connection between the two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. In addition, in the description of this application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance. In the description of the present invention, the meaning of "multiple" is at least two, such as two, three or more, unless otherwise clearly and specifically limited.

[0033] Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] The mainstream calibration method in the world is experimental measurement calibration, that is, experimental measurement calibration is performed through a simulated lung model containing a radioactive source to give a calibration coefficient. Ideally, the physical model should be as close as possible to the human body being measured in terms of tissue equivalence, organ size and shape, and the distribution of radionuclides in the body. However, it is difficult for actual physical models to meet the above requirements, and there are also some difficulties in use.

[0035] On the one hand, these models are expensive, and the materials used to simulate lung models have difficulty in tissue equivalence and model manufacturing in the low-energy range. For example, "large bubbles" are prone to exist during the foaming process of the lung model, resulting in uneven materials and poor tissue equivalence. At present, it is still difficult to produce a low-cost physical model that can meet all in vivo measurement scale requirements. Therefore, various physical models are required for different situations, which increases the cost of model purchase, use and maintenance. Most domestic internal radiation monitoring laboratories do not have these hardware conditions.

[0036] On the other hand, the anatomical structure of the physical model is generally simple, the model size is fixed, and the individual representativeness is poor. The physical model scale is only a "reference" scale method. Since the human body is a relatively complex and large-sized measurement object, individual differences are also large. This difference has a greater impact on low-energy photons. However, it is unrealistic to make corresponding physical models for different individuals.

[0037] First, to facilitate understanding of the embodiments of the present invention, some terms or nouns involved in the present invention are explained below:

[0038] The lung counter is a device that measures the low-energy X-rays and gamma rays emitted by nuclides such as Pu (plutonium) and Am (americium) that are ingested into the body, thereby determining the amount of these nuclides deposited in the lungs.

[0039] Virtual calibration refers to the process of using computer simulation and mathematical models to predict and evaluate the measurement performance of the lung counter under different conditions.

[0040] In order to solve the problems existing in the prior art, the embodiments of the present application provide a method, device and storage medium for determining the virtual scale of a lung counter.

[0041] Example 1

[0042] This embodiment provides a method for determining the virtual scale of a lung counter, such as Figure 1 As shown, Figure 1 is a flow chart of a method for determining a virtual scale of a lung counter in Embodiment 1 of the present invention, such as Figure 2 As shown, Figure 2 It is a technical route block diagram of a method for determining a virtual scale of a lung counter in embodiment 1 of the present invention, the method comprising:

[0043] Step S102, obtaining a simulated lung digital model, wherein the simulated lung digital model includes the lung, soft tissue outside the lung, and hard bone outside the lung;

[0044] Alternatively, a simulated lung digital model is a process of converting a human lung CT scan or other medical imaging data into a three-dimensional digital model through computer technology. The simulated lung digital model can accurately reproduce the anatomical structure and function of the lungs, providing an intuitive visual reference for testers.

[0045] Optionally, during the detection of human lungs, since the entire human torso needs to be detected in real detection, the entire torso of the human body needs to be restored when constructing a simulated lung digital model. Therefore, the lungs to be detected, the hard bones on the outside of the lungs that have a protective effect, and the soft tissue wrapped around the hard bones all need to be constructed, thereby effectively restoring the lungs for detection in a real scene.

[0046] In some preferred embodiments, the method includes: performing a CT scan on a simulated lung model to obtain a CT image, wherein the CT image includes a plurality of different grayscale values; determining the length, width, and height of the lung voxels of the simulated lung model, the length, width, and height of the soft tissue voxels on the outside of the lungs, and the length, width, and height of the hard bone voxels on the outside of the lungs based on the grayscale values ​​in the CT image; constructing a simulated lung digital model based on the length, width, and height of the lung voxels of the simulated lung model, the length, width, and height of the soft tissue voxels on the outside of the lungs, and the length, width, and height of the hard bone voxels on the outside of the lungs.

[0047] Optional, such as Figure 3 As shown, Figure 3 It is a diagram of a simulated lung digital model in a method for determining a virtual scale of a lung counter in Example 1 of the present invention. To construct a simulated lung digital model, it is necessary to perform a CT scan on the simulated lung model, obtain lung CT scan data, and construct a CT image, which is usually stored in a digital imaging and communication (DICOM) format. Secondly, the CT image is preprocessed, specifically including removing noise and enhancing contrast. The imaging quality of the CT image can be improved by preprocessing. Subsequently, the image segmentation technology is used to separate the lungs from other tissues (hard bones and soft tissues), and extract structures such as the airways and blood vessels of the lungs. Specifically, after separation, the voxel information of the simulated lung model is obtained, that is, the length, width and height of the lung voxels, the length, width and height of the soft tissue voxels, and the length, width and height of the hard bone voxels. Through the length, width and height ratio in the above voxel information, a two-dimensional two-dimensional matrix text is constructed, thereby constructing a three-dimensional simulated lung digital model based on the two-dimensional matrix text. In this way, the actual simulated lung model (usually made of rubber) is transformed into a virtual simulated lung digital model. Based on the simulated lung digital model, multiple digital models can be copied, effectively reducing the cost of making the simulated lung model.

[0048] In some preferred embodiments, a simulated lung digital model is constructed based on the length, width and height of the lung voxels of the simulated lung model, the length, width and height of the soft tissue voxels on the outside of the lungs, and the length, width and height of the hard bone voxels on the outside of the lungs, including: determining a two-dimensional matrix text of the lungs based on the length, width and height of the lung voxels of the simulated lung model; determining a two-dimensional matrix text of the soft tissue based on the length, width and height of the soft tissue voxels on the outside of the lungs; determining a two-dimensional matrix text of the hard bone based on the length, width and height of the hard bone voxels on the outside of the lungs; traversing and inputting the two-dimensional matrix text of the lungs in a loop to obtain the lungs of the simulated lung digital model; traversing and inputting the two-dimensional matrix text of the soft tissue in a loop to obtain the soft tissue of the simulated lung digital model; traversing and inputting the two-dimensional matrix text of the hard bone in a loop to obtain the hard bone of the simulated lung digital model; constructing a simulated lung digital model based on the lungs, soft tissue and hard bone.

[0049] Optionally, the length, width and height of the output voxel information are predetermined according to the accuracy requirements of the digital model, and a two-dimensional matrix text is obtained based on the voxel information. The length, width and height data in the two-dimensional matrix text are looped and traversed in sequence, that is, the first layer of the lungs is based on the length, width and height of the first lung voxel to construct a rectangular block, and then the length, width and height of the second lung voxel is used to construct the next rectangular block. All rectangular blocks are listed to form a three-dimensional model of the lungs, that is, the lungs are constructed. By the above-mentioned method of constructing the lungs, the hard bones and soft tissues are constructed, and the constructed lungs, soft tissues and hard bones are spliced ​​to obtain a simulated lung digital model.

[0050] Optionally, after the simulated lung digital model is determined, the simulated lung digital model is post-processed, including at least smoothing, detail enhancement, etc., to improve the fidelity and accuracy of the simulated lung digital model.

[0051] Step S104, forming a radiation source point in the lung based on the simulated lung digital model;

[0052] Optionally, in the actual detection process, the radiation source in the lungs of the person being tested is irregular and randomly infected. Therefore, when placing the radiation source points in the process of forming a simulated lung model, there may be deliberate placement or excessively uneven placement, resulting in subsequent testing that is not close to reality. Therefore, in the simulated lung digital model, the placement of radiation source points needs to balance randomness and uniformity to more effectively approach the actual detection scenario.

[0053] In some preferred embodiments, based on a simulated digital model of the lungs, radiation source points are formed in the lungs, including: constructing an enclosing sphere based on the lungs of the simulated digital model of the lungs; uniformly and randomly placing multiple initial radiation source points in the enclosing sphere; emitting rays with the multiple initial radiation source points as origins, and retaining the initial radiation source points corresponding to odd numbers of intersections of the rays and the lungs; traversing multiple rays emitted with the multiple initial radiation source points as origins, and stopping the traversal when the number of retained initial radiation source points exceeds a preset number; and determining the radiation source points formed in the lungs based on the retained initial radiation source points.

[0054] Optionally, a sphere is constructed in the lungs, and multiple initial radiation source points (x, y, z) are evenly and randomly placed in the sphere. The initial radiation source points are randomly placed and may be placed in the lungs or outside the lungs, effectively approaching the randomness of the radiation source distribution in actual situations. At the same time, based on multiple initial radiation source points as the origin, a ray is emitted from the origin along the positive direction of the x1 axis (the direction from right to left in the lungs). If the intersection of the ray and the lung is an odd number, the point is determined to be inside the lung, otherwise it is outside the lung. The points in the lungs are retained as the positions of the radiation sources until the number of sampling points reaches 20,000, achieving random and approximately uniform distribution of the radiation sources in the lungs.

[0055] Step S106, constructing a detector model by a virtual characterization method;

[0056] Optionally, the detector model is virtually characterized. First, the dead layer thickness of the detector needs to be determined. The dead layer thickness is adjusted by comparing the calculated value of the full energy peak efficiency with the experimental value. According to the comparison result, the dead layer thickness in the detector calculation model is adjusted. The detection efficiency is recalculated with the adjusted parameters. After comparing with the experimental efficiency, the dead layer thickness is adjusted again. This is repeated until the deviation between the calculated value of the full energy peak efficiency of all energies and the experimental value meets the expected requirements. Figure 4 As shown, Figure 4 This is a detector model diagram in a method for determining a virtual scale of a lung counter in Example 1 of the present invention.

[0057] In some preferred embodiments, a detector model is constructed by a virtual characterization method, including: determining the dead layer thickness of the detector model; building the dead layer of the detector model based on the dead layer thickness; and sequentially building an insulating layer, an aluminum bracket, an incident window, and an aluminum shell of the detector model outside the dead layer.

[0058] Optionally, the dead layer thickness is an important parameter of the detector, which refers to a non-sensitive area that particles need to pass through before entering the detector. In this area, particles will lose energy but do not contribute to the signal output. Therefore, it is necessary to accurately measure the thickness of the dead layer. Particle sources with different energies, such as alpha particles of Pu-238, can be used to enter the detector from the detector surface at different incident angles. By recording the energy loss of particles when passing through the dead layer, the thickness of the dead layer can be calculated. Low-energy gamma rays, such as 59.5keV gamma rays of 241Am, can also be used. According to the radioactivity of the known source, the thickness of the dead layer can be inferred by simulating and counting the peak counts of different dead layer thicknesses under the same experimental structure. Based on the obtained dead layer thickness, the calculated value of the full-energy peak efficiency is compared with the experimental value. If the error between the calculated value and the experimental value is low, it means that the dead layer thickness is accurately measured, that is, the dead layer thickness is obtained.

[0059] Optionally, after determining the thickness of the dead layer, the dead layer of the detector model can be built according to the thickness. Simulated metal, plastic or ceramic materials can be selected as the dead layer. These simulated materials should have good mechanical properties and chemical stability to ensure the stability and reliability of the detector. The insulating material is evenly coated on the outside of the dead layer to ensure that the electronic components inside the detector model are isolated from the external environment. Use simulated aluminum material to make a bracket to support and protect the components inside the detector, fix the aluminum bracket to the outside of the insulating layer, and ensure that it is firm and reliable. Select a simulated beryllium window or carbon window material as the incident window, and ensure that it is accurately positioned and well sealed. Fix the aluminum shell to the outside of the incident window, and ensure that it is firm, reliable and well sealed. Based on the above-mentioned simulated materials, a detector model is constructed, and the simulated detector model can effectively restore the actual detector and effectively reduce the detector usage loss.

[0060] In some preferred embodiments, the dead layer thickness of the detector model is determined, including: presetting an initial dead layer thickness; calculating an initial total energy peak efficiency of the detector model based on the initial dead layer thickness; cyclically adjusting the initial dead layer thickness based on a comparison between the initial total energy peak efficiency and a preset efficiency value to obtain a plurality of total energy peak efficiencies; when the difference between the plurality of total energy peak efficiencies and the preset efficiency value is less than a preset error, stopping the cyclic adjustment to obtain the dead layer thickness of the detector model.

[0061] Step S108, placing the detector model in the space where the simulated lung digital model is located;

[0062] In some preferred embodiments, placing the detector model in the space where the simulated lung digital model is located includes: constructing a simulation coordinate system of the simulated lung digital model; and placing the detector model in the space where the simulated lung digital model is located based on the simulation coordinate system.

[0063] Optionally, to reconstruct the coordinate system of the irradiation scenario, first establish a simulation coordinate system for the entire virtual scale system to facilitate confirmation of the positions of various geometric elements in the reconstruction scenario system, that is, to confirm the positions of the detector model and the simulated lung digital model. The principle of establishing a simulation coordinate system is to make the coordinate description of all geometric elements as convenient as possible. Since the digital human body model is the most complex in the entire scenario system, it is selected as the core reference. The simulated lung digital model is composed of voxel information. The midpoint of the first row of voxel information is the origin of the simulation coordinate system. From the front to the back of the simulated lung digital model is the positive direction of the X-axis, from the top to the bottom of the simulated lung digital model is the positive direction of the Z-axis, and from the right to the left of the simulated lung digital model is the positive direction of the Y-axis. Figure 5 As shown, Figure 5 It is a diagram of a simulation coordinate system in a method for determining a virtual scale of a lung counter in Example 1 of the present invention.

[0064] In some preferred embodiments, constructing a simulation coordinate system of a simulated lung digital model includes: determining the length, width, and height of the first row of hard bone voxels in a hard bone two-dimensional matrix text; determining the midpoint of the hard bone based on the length, width, and height of the first row of hard bone voxels; taking the midpoint of the hard bone as the origin, determining the direction from the front chest to the back in the simulated lung digital model as the positive direction of the X-axis; taking the midpoint of the hard bone as the origin, determining the direction from the top of the head to the body in the simulated lung digital model as the positive direction of the Z-axis; taking the midpoint of the hard bone as the origin, determining the direction from the right arm to the left arm in the simulated lung digital model as the positive direction of the Y-axis.

[0065] Step S110, detecting the radiation source points of the simulated lung digital model based on the detector model, and determining the detection efficiency corresponding to the detector model, wherein the detection efficiency is used to indicate the virtual scale of the lung counter.

[0066] In some preferred embodiments, the radiation source points of the simulated lung digital model are detected based on the detector model to determine the detection efficiency corresponding to the detector model, including: the detector model obtains the rays emitted by the radiation source points of the simulated lung digital model; the detector model determines the radiation amount of the radiation source based on the rays; the detector model determines the fluence rate of the radiation source based on the rays; based on the radiation amount and the fluence rate, the number of particles measured by the detector model is determined; based on the number of particles measured by the detector model and the actual total number of particles in the radiation source, the detection efficiency corresponding to the detector model is determined.

[0067] Optionally, during the virtual calibration process, after the detector model and the simulated lung digital model are established, the detector characterization is completed, and the Monte Carlo program physical process is realized, the detection efficiency (i.e., the ratio of the number of particles measured by the detector to the actual total number of particles in the radiation source) is simulated and calculated. After the simulation calculation is completed, it is experimentally verified. Table 1 lists the relative deviations between the simulation efficiency and the experimental efficiency. From the data in Table 1, it can be seen that the relative deviation between the simulation efficiency and the experimental efficiency is small, which verifies the accuracy of the virtual calibration algorithm.

[0068] Table 1 Simulated and calculated detection efficiency

[0069]

[0070] In some preferred embodiments, the detector model determines the radiation amount of the radiation source based on the rays, including: determining the radiation source energy based on the rays; determining the volume and dead layer thickness of the detector model; and integrating based on the radiation source energy, volume and dead layer thickness to obtain the radiation amount of the radiation source.

[0071] Optionally, the energy and volume of the radiation source and the thickness of different media are integrated by a point kernel integration algorithm to obtain the required radiation amount at the measurement point.

[0072] Specifically, the Point Nucleus-Multipoint Integral Method (PNMIM) regards the core parts or key points in a complex problem as "point nuclei" and then performs integral calculations around these point nuclei. When calculating the radiation dose field, the point nucleus integration method is also used to calculate the gamma radiation dose field in three-dimensional space. This method has the advantages of intuitive principle, simple calculation, relatively complete parameters, and fast calculation speed. It is particularly suitable for radiation protection optimization. The core of the point nucleus integration method is to decompose the problem into multiple small parts or sub-problems, then perform integral calculations on each sub-problem, and add up the results to obtain the overall solution. The following steps are involved:

[0073] Determine the point core: First, it is necessary to determine the core part or key point of the problem, that is, the point core. These point cores can be atomic nuclei in molecules and particles in physical systems.

[0074] Model building: Depending on the specific nature of the problem, an appropriate mathematical model is built, which involves expressing the interactions between point cores as functions or integral expressions.

[0075] Integration calculation: Use numerical integration to calculate the integral of each subproblem.

[0076] Accumulate results: Add or multiply the integral results of each sub-problem to get the overall solution.

[0077] In some preferred embodiments, the detector model determines the fluence rate of the radiation source based on the rays, including: obtaining the number of radiation source points; determining the point kernel function from the radiation source point to a preset position based on the rays and the radiation source energy; determining the activity of the radiation source based on the rays; determining the fluence rate of the radiation source based on the number of radiation source points, the point kernel function and the activity of the radiation source.

[0078] Alternatively, a general formula for calculating the fluence rate at a point in the lung for a radiation source is as follows:

[0079]

[0080] Where N is the number of radiation sources, K(E,r→rp) is the distance from the position of the radiation source with energy E at point r to point r. p The point kernel function used for the fluence rate at a point, S0 is the activity of the radioactive source at that location.

[0081] Specifically, the fluence rate, that is, the number of particles passing through a unit area per unit time, is a physical quantity that characterizes the radiation field. In the field of radiology, it is used to describe the density and flow rate of particles emitted by a radiation source at a certain point in space.

[0082] Through the above steps S102 to S110, the purpose of setting up a virtual lung simulation digital model and a detector model and virtually constructing a simulation test is achieved, thereby achieving the technical effect of evenly placing the radiation source and using the virtual model to reduce costs, thereby solving the technical problems of high experimental conditions and high experimental costs due to the difficulty in evenly placing the radiation source in the lung model and the high cost of making the lung model.

[0083] Example 2

[0084] In this embodiment, a device for determining the virtual scale of the lung counter is also provided, and the device is used to implement the above-mentioned embodiments and preferred implementation modes, and the descriptions that have been made will not be repeated. As used below, the terms "module" and "device" can implement a combination of software and / or hardware for a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, the implementation of hardware, or a combination of software and hardware, is also possible and conceivable.

[0085] According to an embodiment of the present invention, there is also provided an embodiment of a device for implementing the above-mentioned method for determining a virtual scale of a lung counter. Figure 6 is a schematic diagram of the structure of a device for determining a virtual scale of a lung counter in Embodiment 2 of the present invention, such as Figure 6 As shown, the above-mentioned lung counter virtual scale determination device includes: an acquisition module 201, a radiation source point module 202, a detector model module 203, a placement module 204 and a detection efficiency determination module 205, wherein:

[0086] An acquisition module 201 is used to acquire a simulated lung digital model, wherein the simulated lung digital model includes the lung, soft tissue outside the lung, and hard bone outside the lung;

[0087] The radiation source point module 202 is connected to the acquisition module 201 and is used to form the radiation source point in the lung based on the simulated lung digital model;

[0088] The detector model module 203 is connected to the radiation source point module 202 and is used to construct a detector model by a virtual characterization method;

[0089] A placement module 204, connected to the detector model module 203, is used to place the detector model in the space where the simulated lung digital model is located;

[0090] The detection efficiency determination module 205 is connected to the placement module 204, and is used to detect the radiation source points of the simulated lung digital model based on the detector model, and determine the detection efficiency corresponding to the detector model, wherein the detection efficiency is used to indicate the virtual scale of the lung counter.

[0091] It should be noted that the above modules can be implemented by software or hardware. For example, for the latter, it can be implemented in the following ways: the above modules can be located in the same processor; or the above modules can be located in different processors in any combination.

[0092] It should be noted that the acquisition module 201, the radiation source position module 202, the detector model module 203, the placement module 204 and the detection efficiency determination module 205 correspond to steps S102 to S110 in the embodiment, and the examples and application scenarios implemented by the modules and the corresponding steps are the same, but are not limited to the contents disclosed in the above embodiments. It should be noted that the modules as part of the device can be run in a computer terminal.

[0093] It should be noted that the optional or preferred implementation of this embodiment can refer to the relevant description in the embodiment, which will not be repeated here.

[0094] The above-mentioned device for determining the virtual scale of a lung counter may also include a processor and a memory. The above-mentioned acquisition module 201, radiation source point module 202, detector model module 203, placement module 204 and detection efficiency determination module 205 are all stored in the memory as program modules, and the processor executes the above-mentioned program modules stored in the memory to realize corresponding functions.

[0095] The processor includes a kernel, which retrieves the corresponding program module from the memory. The kernel may be one or more. The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. The memory includes at least one memory chip.

[0096] According to an embodiment of the present application, an embodiment of a non-volatile storage medium is also provided. Optionally, in this embodiment, the non-volatile storage medium includes a stored program, wherein when the program is running, the device where the non-volatile storage medium is located is controlled to execute any of the above-mentioned methods for determining the virtual scale of the lung counter.

[0097] Optionally, in this embodiment, the non-volatile storage medium may be located in any computer terminal in a computer terminal group in a computer network, or in any mobile terminal in a mobile terminal group, and the non-volatile storage medium includes a stored program.

[0098] Optionally, when the program is running, the device where the non-volatile storage medium is located is controlled to perform the following functions: obtain a simulated lung digital model, wherein the simulated lung digital model includes the lungs, soft tissue outside the lungs, and hard bones outside the lungs; based on the simulated lung digital model, form a radiation source point in the lungs; construct a detector model through a virtual characterization method; place the detector model in the space where the simulated lung digital model is located; based on the detector model, detect the radiation source point of the simulated lung digital model, and determine the detection efficiency corresponding to the detector model, wherein the detection efficiency is used to indicate the virtual scale of the lung counter.

[0099] According to an embodiment of the present application, an embodiment of a processor is also provided. Optionally, in this embodiment, the processor is used to run a program, wherein when the program is run, any of the above methods for determining the virtual scale of the lung counter is executed.

[0100] According to an embodiment of the present application, an embodiment of a computer program product is also provided. Optionally, in this embodiment, the computer program product includes a computer program, and when the computer program is executed by a processor, the computer program implements any of the steps of the method for determining the virtual scale of the lung counter.

[0101] Optionally, the above-mentioned computer program product, when executed on a data processing device, is suitable for executing a program that initializes the following method steps: obtaining a simulated lung digital model, wherein the simulated lung digital model includes the lungs, soft tissue outside the lungs, and hard bones outside the lungs; forming a radiation source point in the lungs based on the simulated lung digital model; constructing a detector model through a virtual characterization method; placing the detector model in the space where the simulated lung digital model is located; detecting the radiation source point of the simulated lung digital model based on the detector model, and determining the detection efficiency corresponding to the detector model, wherein the detection efficiency is used to indicate the virtual scale of the lung counter.

[0102] An embodiment of the present invention provides an electronic device, which includes a processor, a memory, and a program stored in the memory and executable on the processor. When the processor executes the program, the following steps are implemented: obtaining a simulated lung digital model, wherein the simulated lung digital model includes lungs, soft tissue outside the lungs, and hard bones outside the lungs; forming radiation source points in the lungs based on the simulated lung digital model; constructing a detector model through a virtual characterization method; placing the detector model in the space where the simulated lung digital model is located; and detecting the radiation source points of the simulated lung digital model based on the detector model to determine the detection efficiency corresponding to the detector model, wherein the detection efficiency is used to indicate a virtual scale of a lung counter.

[0103] The above sequence of the embodiments of the present invention is for description only and does not represent the superiority or inferiority of the embodiments.

[0104] In the above embodiments of the present invention, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0105] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only schematic. For example, the division of the above modules can be a logical function division. There may be other division methods in actual implementation, such as multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, modules or indirect coupling or communication connection of modules, which can be electrical or other forms.

[0106] The modules described above as separate components may or may not be physically separated, and the components shown as modules may or may not be physical modules, that is, they may be located in one place or distributed on multiple modules. Some or all of the modules may be selected according to actual needs to achieve the purpose of the present embodiment.

[0107] In addition, each functional module in each embodiment of the present invention may be integrated into one processing module, or each module may exist physically separately, or two or more modules may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of software functional modules.

[0108] If the above-mentioned integrated module is implemented in the form of a software function module and sold or used as an independent product, it can be stored in a computer-readable non-volatile storage medium. Based on this understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a non-volatile storage medium, including a number of instructions to enable a computer device (which can be a personal computer, server or network device, etc.) to perform all or part of the steps of the various embodiments of the present invention. The aforementioned non-volatile storage medium includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, magnetic disk or optical disk and other media that can store program codes.

[0109] The above are only preferred embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for determining a virtual scale of a lung counter, characterized in that: include: Acquire a simulated lung digital model, wherein the simulated lung digital model includes the lung, soft tissue outside the lung, and hard bone outside the lung; Based on the simulated lung digital model, forming a radiation source point in the lung; Construct detector models through virtual characterization methods; Placing the detector model in the space where the simulated lung digital model is located; The radiation source points of the simulated lung digital model are detected based on the detector model to determine the detection efficiency corresponding to the detector model, wherein the detection efficiency is used to indicate the virtual scale of the lung counter.

2. The method according to claim 1, characterized in that The step of obtaining a simulated lung digital model comprises: Performing CT scanning on the simulated lung model to obtain a CT image, wherein the CT image includes a plurality of different grayscale values; Based on the grayscale values ​​in the CT image, determining the length, width and height of the lung voxels, the length, width and height of the soft tissue voxels outside the lungs, and the length, width and height of the hard bone voxels outside the lungs of the simulated lung model; The simulated lung digital model is constructed based on the length, width and height of the lung voxels, the length, width and height of the soft tissue voxels outside the lungs and the length, width and height of the hard bone voxels outside the lungs of the simulated lung model.

3. The method according to claim 2, characterized in that The method of constructing the simulated lung digital model based on the lung voxel length, width and height of the simulated lung model, the soft tissue voxel length, width and height outside the lung, and the hard bone voxel length, width and height outside the lung comprises: Determining a two-dimensional matrix text of the lungs based on the length, width and height of the lung voxels of the simulated lung model; Determine a two-dimensional matrix text of the soft tissue based on the length, width and height of the soft tissue voxels outside the lung; Determine a two-dimensional matrix text of the hard bone based on the length, width and height of the hard bone voxel outside the lung; Traversing and looping to input the two-dimensional matrix text of the lungs, and obtaining the lungs of the simulated lung digital model; Traversing and looping to input the soft tissue two-dimensional matrix text to obtain the soft tissue of the simulated lung digital model; Traversing and looping to input the hard bone two-dimensional matrix text to obtain the hard bone of the simulated lung digital model; The simulated lung digital model is constructed based on the lung, the soft tissue and the hard bone.

4. The method according to claim 1, characterized in that: The forming of radiation source points in the lungs based on the simulated lung digital model includes: Based on the lungs of the simulated lung digital model, constructing an enclosing sphere; Uniformly and randomly placing a plurality of initial radiation source points within the enclosing sphere; respectively emitting rays with the multiple initial radiation source points as origins, and retaining the intersections of the rays and the lungs as initial radiation source points corresponding to odd numbers; Traversing a plurality of rays emitted from the plurality of initial radiation source points as origins, and stopping the traversal when the number of retained initial radiation source points exceeds a preset number; Based on the retained initial radiation source point, the radiation source point formed in the lung is determined.

5. The method according to claim 1, characterized in that The detector model is constructed through virtual characterization methods, including: Determining the dead layer thickness of the detector model; Based on the dead layer thickness, constructing the dead layer of the detector model; The insulating layer, aluminum bracket, incident window and aluminum shell of the detector model are sequentially built outside the dead layer.

6. The method according to claim 5, characterized in that Determining the dead layer thickness of the detector model includes: Preset initial dead layer thickness; Calculating the initial full energy peak efficiency of the detector model based on the initial dead layer thickness; Based on the comparison between the initial full-energy peak efficiency and a preset efficiency value, the initial dead layer thickness is cyclically adjusted to obtain multiple full-energy peak efficiencies; When the difference between the multiple full-energy peak efficiencies and the preset efficiency value is less than a preset error, the cyclic adjustment is stopped to obtain the dead layer thickness of the detector model.

7. The method according to claim 3, characterized in that Placing the detector model in the space where the simulated lung digital model is located includes: Constructing a simulation coordinate system of the simulated lung digital model; Based on the simulation coordinate system, the detector model is placed in the space where the simulated lung digital model is located.

8. The method according to claim 7, characterized in that Constructing a simulation coordinate system of the simulated lung digital model includes: Determine the length, width and height of the first row of hard bone voxels in the hard bone two-dimensional matrix text; Determine the midpoint of the hard bone based on the length, width and height of the hard bone voxels in the first row; Taking the midpoint of the hard bone as the origin, determining the direction from the front chest to the back in the simulated lung digital model as the positive direction of the X-axis; Taking the midpoint of the hard bone as the origin, determining the direction from the top of the head to the body in the simulated lung digital model as the positive direction of the Z axis; Taking the midpoint of the hard bone as the origin, the direction from the right arm to the left arm in the simulated lung digital model is determined to be the positive direction of the Y axis.

9. The method according to claim 1, characterized in that: The detecting the radiation source points of the simulated lung digital model based on the detector model and determining the detection efficiency corresponding to the detector model includes: The detector model acquires the radiation emitted by the radiation source point of the simulated lung digital model; The detector model determines the radiation amount of the radiation source based on the ray; The detector model determines a fluence rate of the radiation source based on the ray; Determining the number of particles measured by a detector model based on the radiation amount and the fluence rate; Based on the number of particles measured by the detector model and the actual total number of particles in the radiation source, the detection efficiency corresponding to the detector model is determined.

10. The method according to claim 9, characterized in that The detector model determines the radiation amount of the radiation source based on the ray, including: Based on the radiation, determining the energy of the radiation source; Determine the volume of the detector model and the dead layer thickness; The radiation amount of the radiation source is obtained by integrating the radiation source energy, the volume and the dead layer thickness.

11. The method according to claim 10, characterized in that The detector model determines the fluence rate of the radiation source based on the ray, including: Get the number of radiation source points; Based on the ray and the energy of the radiation source, determining a point kernel function from the radiation source point to a preset position; determining the activity of the radiation source based on the radiation; The fluence rate of the radiation source is determined based on the number of the radiation source points, the point kernel function and the activity of the radiation source.

12. A device for determining a virtual scale of a lung counter, characterized in that: include: An acquisition module, used for acquiring a simulated lung digital model, wherein the simulated lung digital model includes the lung, soft tissue outside the lung, and hard bone outside the lung; A radiation source point module, used for forming radiation source points in the lungs based on the simulated lung digital model; A detector model module, used to construct a detector model through a virtual characterization method; A placement module, used for placing the detector model in the space where the simulated lung digital model is located; The detection efficiency determination module is used to detect the radiation source points of the simulated lung digital model based on the detector model, and determine the detection efficiency corresponding to the detector model, wherein the detection efficiency is used to indicate the virtual scale of the lung counter.

13. A non-volatile storage medium, characterized in that: The non-volatile storage medium stores a plurality of instructions, and the instructions are suitable for being loaded by a processor and executing a method for determining a virtual scale of a lung counter as described in any one of claims 1 to 11.

14. A computer program product comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of a method for determining a virtual scale of a lung counter as described in any one of claims 1 to 11 are implemented.

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