Gamma detector efficiency calibration method and device based on numerical integration

Abstract

The invention provides a gamma detector efficiency calibration method, device and equipment based on numerical integration, a medium and a program product. The method comprises the following steps: acquiring point source efficiency spatial distribution of a gamma detector; voxelizing the body source model of the to-be-detected body source to obtain a plurality of voxels; obtaining position efficiency corresponding to each voxel based on matching of the position information of each voxel and a point source position in point source efficiency space distribution; obtaining the distance from each voxel to the surface of the body source model in the ray direction pointing to the detection center of the gamma detector from each voxel, so as to obtain the attenuation length of each voxel; obtaining voxel efficiency of each voxel based on the attenuation length and the position efficiency of each voxel and the material attenuation coefficient of the to-be-measured body source; and processing the voxel efficiency of multiple voxels based on a passive efficiency calibration method of numerical integration to obtain the detection efficiency of the gamma detector on the to-be-detected body source.

Description

Technical Field

[0001] The present disclosure relates to the field of detection efficiency calibration of gamma detectors, and in particular to a method, device, equipment, medium and program product for gamma detector efficiency calibration based on numerical integration. Background Art

[0002] A gamma detector is a device specially designed to detect and measure gamma rays. The detection efficiency of a gamma detector refers to the ratio of the gamma ray events that the detector can successfully detect to the total number of gamma ray events that are emitted. The radioactive sample emits gamma rays, which are incident on the detector and successfully detected by the detector, forming counts on the detector. The activity of the radioactive sample can then be inferred from the counts on the detector and the detection efficiency. Therefore, before detecting the activity of the radioactive sample, the detection efficiency needs to be calibrated.

[0003] A basic detection efficiency calibration method is to use a standard radioactive source of known activity under the same test conditions as the radioactive sample to calculate the detection efficiency, but this method is very time-consuming and economically expensive. Another commonly used detection efficiency calibration method is to perform passive efficiency calibration based on the computer Monte Carlo simulation method. The Monte Carlo method simulates the process of gamma particle transport. By inputting the detector size, material, sample position, size, material and other test conditions, the detection efficiency under the test conditions can be obtained. However, this method has a large error and a short running time when the number of particles is small; when the number of particles is large, the error is small and the running time is long. Therefore, in order to ensure that the error level meets the required requirements, it often takes a long running time. At present, there is also a passive efficiency calibration method based on numerical integration. Compared with the Monte Carlo method, it can improve the running efficiency of the calculation and reduce the running time while ensuring the error level of the calculation results.

[0004] The above information disclosed in this section is only for understanding the background of the inventive concept of the present disclosure and therefore the above information may contain information that does not constitute the prior art. Summary of the invention

[0005] In view of this, the present disclosure provides a gamma detector efficiency calibration method based on numerical integration.

[0006] According to a first aspect of an embodiment of the present disclosure, a method for calibrating the efficiency of a gamma detector based on numerical integration is provided. The method comprises: firstly obtaining the spatial distribution of the point source efficiency of the gamma detector, wherein the spatial distribution of the point source efficiency is information on how the detection efficiency of the gamma detector for a point source varies with the point source position of the point source; then voxelizing the volume source model of the volume source to be measured to obtain a plurality of voxels, wherein the volume source model is a closed polyhedron; then, based on the matching of the position information of each voxel with the point source position in the point source efficiency spatial distribution, obtaining the position efficiency corresponding to each voxel, wherein the position information of each voxel is obtained based on the position information of the volume source model and the position of each voxel in the volume source model, and the position information of the volume source model is obtained according to the position of the volume source to be measured in space; then the distance from each voxel to the surface of the volume source model in the direction of the ray pointing from each voxel to the detection center of the gamma detector is obtained to obtain the attenuation length of each voxel; next, based on the attenuation length of each voxel and the material attenuation coefficient of the volume source to be measured, the attenuation ratio of each voxel is obtained; and based on the position efficiency and the attenuation ratio of each voxel, the voxel efficiency of each voxel is obtained; finally, the voxel efficiency of the multiple voxels is processed based on the passive efficiency calibration method of numerical integration to obtain the detection efficiency of the gamma detector for the volume source to be measured.

[0007] According to some embodiments of the present disclosure, obtaining the distance from each voxel to the surface of the volume source model in the direction of rays pointing from each voxel to the detection center of the gamma detector to obtain the attenuation length of each voxel includes: when the volume source model is an axisymmetric model and the axis of symmetry coincides with the axis of symmetry of the gamma detector, calculating the attenuation length of each voxel through a two-dimensional geometric relationship in a two-dimensional plane where each voxel and the axis of symmetry are located; wherein the detection center of the gamma detector is on the axis of symmetry of the gamma detector.

[0008] According to some embodiments of the present disclosure, when the volume source model is an axisymmetric model and the axis of symmetry coincides with the axis of symmetry of the gamma detector, in the two-dimensional plane where each voxel and the axis of symmetry are located, calculating the attenuation length of each voxel through the two-dimensional geometric relationship specifically includes: first, determining the target two-dimensional plane based on the target voxel and the axis of symmetry, wherein the target voxel is any one of the multiple voxels; then obtaining the first position information of the target voxel in the target two-dimensional plane and the second position information of the detection center in the target two-dimensional plane; then obtaining the target angle information based on the angle between the target ray direction pointing from the first position information to the second position information and a predefined reference direction in the target two-dimensional plane; next, obtaining the boundary position information of the surface of the volume source model in the target ray direction based on the position information of the volume source model and the target angle information; then the attenuation length of the target voxel can be obtained based on the boundary position information and the first position information.

[0009] According to some embodiments of the present disclosure, obtaining the distance from each voxel to the surface of the volume source model in the direction of rays pointing from each voxel to the detection center of the gamma detector to obtain the attenuation length of each voxel includes: when the volume source model is a non-axisymmetric model or the volume source model is an axisymmetric model but the axis of symmetry does not coincide with the axis of symmetry of the gamma detector, calculating the attenuation length of each voxel based on the three-dimensional geometric relationship in space among each voxel, the volume source model and the detection center.

[0010] According to some embodiments of the present disclosure, obtaining the position efficiency corresponding to each voxel based on matching the position information of each voxel with the point source position in the point source efficiency spatial distribution includes: based on the position information of each voxel, finding at least one point source position from the point source efficiency spatial distribution; and obtaining the position efficiency corresponding to each voxel based on the point source efficiency corresponding to the at least one point source position in the point source efficiency spatial distribution.

[0011] According to some embodiments of the present disclosure, obtaining the position efficiency corresponding to each voxel based on the point source efficiency corresponding to the at least one point source position in the point source efficiency spatial distribution includes: when the at least one point source position is a point source position, taking the point source efficiency of the point source position as the position efficiency; or when the at least one point source position includes multiple point source positions, interpolating the point source efficiencies of the multiple point source positions to obtain the position efficiency.

[0012] According to an embodiment of the present disclosure, the spatial distribution of point source efficiency is represented by a grid or a fitting function.

[0013] According to an embodiment of the present disclosure, the passive efficiency calibration method based on numerical integration processes the voxel efficiency of the multiple voxels to obtain the detection efficiency of the gamma detector for the body source to be measured, including: integrating the voxel efficiency of the multiple voxels and then averaging them to obtain the detection efficiency of the gamma detector for the body source to be measured.

[0014] According to a second aspect of the disclosed embodiment, a gamma detector efficiency calibration device based on numerical integration is provided, which includes a first acquisition module, a voxelization module, a matching module, a second acquisition module, a first processing module and a numerical integration module.

[0015] The first acquisition module is used to acquire the point source efficiency spatial distribution of the gamma detector, where the point source efficiency spatial distribution is information about how the detection efficiency of the gamma detector for a point source varies with the point source position of the point source.

[0016] The voxelization module is used to voxelize the volume source model of the volume source to be measured to obtain a plurality of voxels, wherein the volume source model is a closed polyhedron.

[0017] The matching module is used to obtain the position efficiency corresponding to each voxel based on the matching of the position information of each voxel with the point source position in the point source efficiency spatial distribution, wherein the position information of each voxel is obtained based on the position information of the volume source model and the position of each voxel in the volume source model, and the position information of the volume source model is obtained according to the position of the volume source to be measured in space.

[0018] The second acquisition module is used to acquire the distance from each voxel to the surface of the volume source model in the direction of the ray pointing from each voxel to the detection center of the gamma detector, so as to obtain the attenuation length of each voxel.

[0019] The first processing module is used to obtain the attenuation ratio of each voxel based on the attenuation length of each voxel and the material attenuation coefficient of the volume source to be measured, and to obtain the voxel efficiency of each voxel based on the position efficiency and the attenuation ratio of each voxel.

[0020] The numerical integration module is used for processing the voxel efficiency of the plurality of voxels based on a passive efficiency calibration method of numerical integration to obtain the detection efficiency of the gamma detector for the volume source to be detected.

[0021] According to some embodiments of the present disclosure, the second acquisition module includes a coaxial axisymmetric submodule. The coaxial axisymmetric submodule is used to calculate the attenuation length of each voxel in the two-dimensional plane where each voxel and the axis of symmetry are located by a two-dimensional geometric relationship when the volume source model is an axisymmetric model and the axis of symmetry coincides with the axis of symmetry of the gamma detector; wherein the detection center of the gamma detector is on the axis of symmetry of the gamma detector.

[0022] According to some embodiments of the present disclosure, the coaxial axisymmetric submodule is used to: determine a target two-dimensional plane based on a target voxel and the axis of symmetry, wherein the target voxel is any one of the multiple voxels; obtain first position information of the target voxel in the target two-dimensional plane and second position information of the detection center in the target two-dimensional plane; obtain target angle information based on an angle between a target ray direction pointing from the first position information to the second position information and a predefined reference direction in the target two-dimensional plane; obtain boundary position information of the surface of the volume source model in the target ray direction based on the position information of the volume source model and the target angle information; and obtain the attenuation length of the target voxel based on the boundary position information and the first position information.

[0023] According to an embodiment of the present disclosure, the second acquisition module includes a non-coaxial axisymmetric submodule. The non-coaxial axisymmetric submodule is used to calculate the attenuation length of each voxel based on the three-dimensional geometric relationship between each voxel, the volume source model and the detection center in space when the volume source model is a non-axisymmetric model or the volume source model is an axisymmetric model but the symmetry axis does not coincide with the symmetry axis of the gamma detector.

[0024] According to some embodiments of the present disclosure, the matching module is used to: find at least one point source position from the point source efficiency spatial distribution based on the position information of each voxel; and obtain the position efficiency corresponding to each voxel based on the point source efficiency corresponding to the at least one point source position in the point source efficiency spatial distribution.

[0025] According to some embodiments of the present disclosure, the numerical integration module is used to: integrate the voxel efficiencies of the multiple voxels and calculate the average value to obtain the detection efficiency of the gamma detector for the volume source to be detected.

[0026] According to a third aspect of the embodiments of the present disclosure, an electronic device is provided. The electronic device comprises: one or more processors and a memory. The memory is used to store one or more computer programs. The one or more processors execute the one or more computer programs to implement the steps of the above method.

[0027] According to a fourth aspect of an embodiment of the present disclosure, a computer-readable storage medium is provided, on which a computer program or instructions are stored, wherein the computer program or instructions implement the steps of the above method when executed by a processor.

[0028] According to a fifth aspect of an embodiment of the present disclosure, a computer program product is provided, including a computer program or instructions, wherein the steps of the above method are implemented when the computer program or instructions are executed by a processor.

[0029] One or more of the above embodiments have the following advantages or beneficial effects: when the passive efficiency calibration method based on numerical integration is applied to the calibration process of the detection efficiency of the body source to be measured, the body source to be measured can be simulated as a body source model, and the distance from each voxel in the body source model to the surface of the body source model in the direction of the ray pointing to the detection center of the gamma detector is taken as the attenuation length required in the calculation, which simplifies the acquisition of the attenuation length in the efficiency calibration process, and then the voxel efficiency of each voxel can be obtained according to the acquired attenuation length, the material attenuation coefficient of the body source to be measured, and the position efficiency of each voxel, so as to obtain the detection efficiency of the gamma detector for the body source to be measured by numerically integrating the voxel efficiencies of all voxels in the body source model. In this process, the operation efficiency of the passive efficiency calibration method based on numerical integration can be further improved by quickly determining and acquiring the attenuation length. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The above and other objects, features and advantages of the present disclosure will become more apparent through the following description of the embodiments of the present disclosure with reference to the accompanying drawings, in which:

[0031] Figure 1 A schematic diagram showing the construction principle of the point source efficiency spatial distribution according to an embodiment of the present disclosure is shown;

[0032] Figure 2 A schematic diagram showing a scene of a gamma detector detecting a sample;

[0033] Figure 3 A schematic flow chart of a passive efficiency calibration method based on numerical integration is shown;

[0034] Figure 4 A flow chart of a method for calibrating gamma detector efficiency based on numerical integration according to an embodiment of the present disclosure is shown;

[0035] Figure 5 A schematic diagram showing the attenuation length of a voxel obtained in one embodiment of the present disclosure is shown;

[0036] Figure 6 A flow chart of obtaining voxel attenuation length for a coaxial axisymmetric volume source model in one embodiment of the present disclosure is shown;

[0037] Figure 7 A flow chart showing the efficiency of obtaining the position corresponding to each voxel through matching in one embodiment of the present disclosure is shown;

[0038] Figure 8 A schematic structural diagram of a gamma detector efficiency calibration device based on numerical integration according to an embodiment of the present disclosure is shown; and

[0039] Fig. 9A schematic structural diagram of an electronic device suitable for implementing a gamma detector efficiency calibration method based on numerical integration according to various embodiments of the present disclosure is shown. DETAILED DESCRIPTION

[0040] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present disclosure. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present disclosure. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present disclosure.

[0041] The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure. The terms "comprise", "include", etc. used herein indicate the existence of the features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0042] All terms (including technical and scientific terms) used herein have the meanings commonly understood by those skilled in the art unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0043] When using expressions such as "at least one of A, B, and C, etc.", they should generally be interpreted according to the meaning of the expression commonly understood by those skilled in the art (for example, "a system having at least one of A, B, and C" should include but is not limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.).

[0044] Figure 1 A schematic diagram showing the construction principle of the point source efficiency spatial distribution according to an embodiment of the present disclosure is shown.

[0045] Combination Figure 1The point source efficiency spatial distribution of the gamma detector 101 is information about how the detection efficiency of the gamma detector 101 for point sources (such as point sources P1, P2, and P3 in the figure) varies with the point source position of the point source. The detection efficiency of point sources at any position around the gamma detector 101 can be obtained through the point source efficiency spatial distribution of the gamma detector 101. For example, according to the point source position of point source P1, the detection efficiency of the gamma detector 101 for point source P1 (hereinafter referred to as "point source efficiency") can be determined from the point source efficiency spatial distribution. Correspondingly, according to the point source positions of point sources P2 and P3, the point source efficiencies of point sources P2 and P3 can be determined from the point source efficiency spatial distribution. Among them, the point source efficiency spatial distribution can be represented by grid points or by a fitting function.

[0046] The point source P1 is located directly above the gamma detector 101. The gamma rays emitted by the point source P1 within the cone angle θ1 can reach the gamma detector 101, and a portion of them can be successfully detected by the gamma detector 101 and form counts. The ratio of the successfully detected counts to the number of rays emitted by the point source P1 is the point source efficiency of the point source P1.

[0047] Point source P2 is located above and to the side of the gamma detector 101. Gamma rays emitted by point source P2 within a cone angle of θ2 can reach the gamma detector 101, and a portion of them can be successfully detected by the gamma detector 101 and form counts. The ratio of the successfully detected counts to the number of rays emitted by P2 is the point source efficiency of point source P2.

[0048] Point source P3 is located directly to the side of the gamma detector 101. The gamma rays emitted by point source P3 within the cone angle θ3 can reach the gamma detector 101, and a portion of them can be successfully detected by the gamma detector 101 and form counts. The ratio of the successfully detected counts to the number of rays from point source P3 is the point source efficiency of point source P3.

[0049] For a specific gamma detector, the size and material of the detector are determined, so the spatial distribution of the point source efficiency is determined. Therefore, after obtaining the data such as the size, dead layer thickness, and material of the gamma detector 101, the spatial distribution of the point source efficiency of the gamma detector 101 can be constructed through simulation or testing, thereby forming a point source efficiency library. Generally, the dimensions of the detector, especially the dead layer thickness, need to be calibrated before leaving the factory, so these calibrated dimensions can be used to simulate and test the spatial distribution of the point source efficiency of the detector. In one embodiment, the spatial distribution of the point source efficiency can be constructed based on the passive efficiency calibration method. For example, the calculation formulas for the point source efficiencies of point sources P1, P2, and P3 can be constructed respectively.

[0050] It should be noted that the gamma detector 101 is illustrated as a cylindrical detector for only an example, and the present disclosure does not limit the shape of the gamma detector.

[0051] Figure 2 A schematic diagram of a scene in which the gamma detector 101 detects the sample 201 is shown.

[0052] Combination Figure 1 and Figure 2 When applying the passive efficiency calibration method based on numerical integration, the internal space of the sample 201 can be regarded as containing a large number of point sources, so that the detection efficiency of the gamma detector 101 for the sample 201 can be calculated based on the point source efficiency integral effect of all the point sources contained in the internal space of the sample 201. However, in this process, it is necessary to pay attention to the following problem: when constructing the point source efficiency distribution space, the point sources (such as P1, P2, and P3) therein are often regarded as being in the air, that is, the gamma rays emitted by the point sources only undergo propagation and attenuation in the air on the path to the surface of the gamma detector 101, while the gamma rays emitted by any point in the internal space of the sample 201 need to propagate to the surface of the sample 201 first, and then propagate through the air to reach the gamma detector 101. Therefore, after obtaining the point source efficiency space distribution, when applying the passive efficiency calibration method based on numerical integration to the sample 201, the attenuation of the rays inside the sample 201 also needs to be considered.

[0053] Figure 3 FIG. 4 shows a flow chart of the passive efficiency calibration method based on numerical integration. Figure 3 As shown, when the passive efficiency calibration method based on numerical integration is applied to a body source to be tested such as sample 201, it mainly includes steps S1 to S6.

[0054] Step S1, voxelization of the volume source model. The volume source model is a simulation of the volume source to be measured in a computer.

[0055] The volume source to be measured refers to a sample with a certain volume and gamma radioactivity, such as sample 201. Common forms include aerosols, liquids, powders, etc., which may be placed in containers such as beakers, boxes, and cans, or they may be three-dimensional irregular shapes such as stones and processed parts. When the volume source to be measured is modeled into a volume source model, it can be regarded as a closed polyhedron with internal space and external space. The internal space of the volume source model can be regarded as a certain number of voxels arranged according to certain rules.

[0056] The voxelization of the volume source model is to divide the internal space of the volume source model into voxels. The arrangement rule here can be uniform arrangement or random arrangement.

[0057] Step S2, constructing a point source efficiency spatial distribution according to the parameters of the gamma detector, for example, storing it in the form of a point source efficiency library. The construction principle of the point source efficiency spatial distribution or the point source efficiency library can refer to Figure 1 The introduction of will not be repeated here.

[0058] Step S3, searching and calculating the position efficiency corresponding to the voxel according to the position of the voxel and the point source efficiency library.

[0059] Specifically, a certain number of voxels can be obtained after voxelization. According to the position of each voxel, the efficiency value of its corresponding position can be found in the point source efficiency library of the gamma detector (referred to as "position efficiency" in this article). The position efficiency can be obtained by using the point source efficiency of points near the position of the voxel, or by interpolation calculation.

[0060] The position efficiency obtained here is the efficiency value without attenuation inside the measured body source. Therefore, for each voxel, it is necessary to calculate the attenuation it has undergone inside the measured body source. The calculation of the attenuation degree needs to consider two factors: the attenuation length that the ray on the voxel has passed inside the measured body source before reaching the gamma detector and the material attenuation coefficient of the measured body source.

[0061] Step S4, calculating the attenuation length of the voxel according to the volume source model and the position of the voxel.

[0062] Step S5, calculating the material attenuation coefficient according to the material of the source to be measured, and calculating the attenuation ratio in combination with the attenuation length. , where u is the material attenuation coefficient and l is the attenuation length.

[0063] Step S6, the voxel efficiency of each voxel can be obtained according to the position efficiency and attenuation ratio of the voxel, and then the voxel efficiency of all voxels in the volume source model is integrated and averaged according to the passive efficiency calibration method based on numerical integration to obtain the volume source efficiency, which is the detection efficiency of the gamma detector for detecting the volume source to be measured.

[0064] By obtaining the voxel efficiency of all voxels in the volume source model, the spatial distribution of the voxel efficiency of the volume source to be measured is obtained. In this way, the passive efficiency calibration method based on numerical integration can effectively improve the operating efficiency of the efficiency calibration and reduce the running time while ensuring the error level of the calculation results by numerically integrating the spatial distribution of the voxel efficiency of the volume source to be measured.

[0065] Continue to refer Figure 1 and Figure 2, assuming that the voxel V1 in the internal space of the sample 201 corresponds to the position of the point source P1 (to simplify the reasoning, assume that the point source P1 and the voxel V1 coincide in space). Since the rays incident on the gamma detector 101 by the point source P1 include all rays within the cone angle θ1, when calculating the attenuation length of the rays emitted by the voxel V1 in the above step S4, it is theoretically necessary to consider the integral effect of the attenuation length corresponding to the propagation of all rays of the voxel V1 within the cone angle θ1 in the sample 201.

[0066] However, in the process of calculating the attenuation length in the above step S4, the inventors found that all the rays incident on the gamma detector 101 by each voxel inside the sample 201 basically present a symmetrical distribution trend centered on the line direction of the voxel and the detection center O of the gamma detector 101. Therefore, the inventors considered that the attenuation length of the rays in the line direction of the voxel (such as voxel V1) and the detection center O of the gamma detector 101 inside the body source can be taken to simplify the calculation and thus improve the calculation efficiency. Moreover, since the voxel efficiency of all voxels in the body source is integrated and averaged in step S6, the influence (or error) brought by the simplified calculation of the attenuation length can be significantly offset. In view of the above concept, the inventors have confirmed the feasibility of their speculation through experimental testing and verification.

[0067] Therefore, the embodiments of the present disclosure provide a method, apparatus, device, medium and program product for gamma detector efficiency calibration based on numerical integration, which can quickly calculate the attenuation length of voxels in the body source to be measured, and further improve the operating efficiency of the passive efficiency calibration method based on numerical integration while ensuring the error level.

[0068] The following will be combined Figure 2 Application scenarios, through Figure 4~Figure 7 The method of the embodiment of the present disclosure is introduced in detail.

[0069] Figure 4 A flow chart of a method for calibrating gamma detector efficiency based on numerical integration according to an embodiment of the present disclosure is shown.

[0070] like Figure 4 As shown, according to an embodiment of the present disclosure, the method may include operations S41 to S47.

[0071] In operation S41, a point source efficiency spatial distribution of the gamma detector is obtained, where the point source efficiency spatial distribution is information on how the detection efficiency of the gamma detector for a point source varies with the point source position of the point source.

[0072] In operation S42 , the volume source model of the volume source to be measured is voxelized to obtain a plurality of voxels, wherein the volume source model is a closed polyhedron.

[0073] In operation S43 , based on the matching of the position information of each voxel with the point source position in the point source efficiency spatial distribution, the position efficiency corresponding to each voxel is obtained.

[0074] The position information of each voxel (such as voxel V1) is obtained based on the position information of the volume source model and the position of each voxel in the volume source model.

[0075] The position information of the volume source model is obtained according to the position of the volume source to be measured in space. Figure 2 In the present invention, a coordinate system can be established with the center of the upper surface of the gamma detector 101 (or the detection center) as the origin, so as to obtain the position information of the sample 201 in space. The position information of the sample 201 can include the coordinate range of the sample 201 in space, such as the coordinate of a certain point on the sample 201, and the regional coordinate range of the sample 201 in space obtained by combining the size of the sample 201. These position information are input into the computer to obtain the position information of the volume source model.

[0076] In operation S44 , the distance from each voxel to the surface of the volume source model in the direction of the ray pointing from each voxel to the detection center of the gamma detector is acquired to obtain the attenuation length of each voxel.

[0077] Combination Figure 2 and Figure 5 Specifically, for the convenience of explanation, Figure 2 The sample 201 is an axisymmetric model, specifically a Marlin cup, and the relative arrangement of the sample 201 and the gamma detector 101 (such as the detector 101 is arranged in a small cylinder hollowed out in the middle of the Marlin cup) makes the symmetry axes of the sample 201 and the gamma detector 101 coincide, which can be referred to as a coaxial axisymmetric structure. The axisymmetric module in this article refers to a three-dimensional model that can be rotated 360° along the axis of symmetry.

[0078] Figure 5 Can be regarded as Figure 2 A cross-sectional view of , wherein the cross-section is a plane where the symmetry axis L is located and is perpendicular to the user-implemented plane, assuming that the voxel V1 is on the cross-section.

[0079] Combination Figure 2 and Figure 5 In operation S44 , for the voxel V1 , the distance between the voxel V1 and the intersection point Q may be taken as the attenuation length, wherein the intersection point Q is the intersection point of the ray from the voxel V1 to the detection center O and the surface of the sample 201 .

[0080] In operation S45 , the attenuation ratio of each voxel is obtained based on the attenuation length of each voxel and the material attenuation coefficient of the volume source to be measured.

[0081] Specifically, the material element composition of the source to be measured or the percentage of the material elements can be input, and then the material attenuation coefficient of the source to be measured can be obtained by weighted calculation based on the attenuation coefficient of each element and then multiplied by the material density. Figure 3 The attenuation ratio of each voxel is calculated in the manner described in step S5.

[0082] In operation S46, based on the position efficiency and the attenuation ratio of each voxel, the voxel efficiency of each voxel is obtained. For each voxel, the position efficiency and the attenuation ratio are multiplied to obtain the voxel efficiency of each voxel.

[0083] In operation S47, the voxel efficiency of multiple voxels is processed based on the passive efficiency calibration method of numerical integration to obtain the detection efficiency of the gamma detector for the volume source to be detected. For example, the voxel efficiency of multiple voxels can be integrated and averaged to obtain the detection efficiency of the gamma detector for the volume source to be detected.

[0084] In this way, when the passive efficiency calibration method based on numerical integration is applied to calibrate the detection efficiency of the body source to be detected, the attenuation length required in the process can be quickly calculated, thereby further improving the operating efficiency of the passive efficiency calibration method based on numerical integration.

[0085] According to an embodiment of the present disclosure, in the above operation S44, when the volume source model is an axisymmetric model and the axis of symmetry coincides with the axis of symmetry of the gamma detector 101 (eg Figure 2 and Figure 5 In the example shown in the example, the attenuation length of each voxel can be calculated by the two-dimensional geometric relationship in the two-dimensional plane where each voxel and the symmetry axis are located. In this way, compared with the calculation based on the three-dimensional geometric relationship in space, the calculation time can be effectively saved.

[0086] It should be noted that Figure 2 The sample 201 is only an example of an axisymmetric body source model. The axisymmetric body source model can also be, for example, a cylinder, a Marlin cup, a sphere, a beaker, etc., which is not limited in the present disclosure.

[0087] Figure 6 A flow chart of obtaining the voxel attenuation length for a coaxially symmetrical volume source model in operation S44 in one embodiment of the present disclosure is shown.

[0088] like Figure 6 As shown, operation S44 may include operations S441 to S445. Figure 2 and Figure 5 , explanation is as follows.

[0089] In operation S441 , a target two-dimensional plane is determined based on a target voxel and an axis of symmetry, wherein the target voxel is any one of a plurality of voxels.

[0090] If the target voxel is voxel V1, then the target two-dimensional plane is Figure 5 The plane shown in .

[0091] During execution, the voxels in the volume source model may be traversed, wherein each traversed voxel may be used as a target voxel.

[0092] In operation S442 , first position information of the target voxel V1 in the target two-dimensional plane and second position information of the detection center O in the target two-dimensional plane are acquired.

[0093] In operation S443, target angle information is obtained based on the angle between the target ray direction pointing from the first position information to the second position information and a predefined reference direction in the target two-dimensional plane. The reference direction may be, for example, the direction of the symmetry axis L, or a direction perpendicular to the symmetry axis L.

[0094] In operation S444, based on the position information of the volume source model and the target angle information, boundary position information of the surface of the volume source model in the target ray direction is obtained.

[0095] Specifically, the surface contour of the out-of-body source model in the target two-dimensional plane can be determined by combining the position information of the out-of-body source model in the target two-dimensional plane. Combined with the target angle information, the boundary position information of the intersection point Q of the out-of-body source model in the target two-dimensional plane in the direction of the ray from the voxel V1 to the detection center O can be determined.

[0096] In operation S445, the attenuation length of the target voxel is obtained based on the boundary position information and the first position information. Figure 5 The distance between the intersection point Q and the voxel V1 is calculated in the two-dimensional plane to obtain the attenuation length of the voxel V1.

[0097] It can be seen that for the coaxial axisymmetric body source sample, the attenuation length is calculated using the two-dimensional geometric relationship, which saves calculation time.

[0098] According to other embodiments of the present disclosure, when the volume source model is a non-axisymmetric model or the volume source model is an axisymmetric model but the axis of symmetry does not coincide with the axis of symmetry of the gamma detector, the attenuation length of each voxel is calculated based on the three-dimensional geometric relationship between each voxel, the volume source model and the detection center in space to adapt to a wider range of application scenarios.

[0099] Figure 7 A flowchart of obtaining the position efficiency corresponding to each voxel through matching in operation S43 in one embodiment of the present disclosure is shown.

[0100] like Figure 7 As shown, according to this embodiment, operation S43 may include operation S431 to operation S432.

[0101] In operation S431, based on the position information of each voxel, at least one point source position is found from the point source efficiency spatial distribution.

[0102] In operation S432, based on the point source efficiency corresponding to at least one point source position in the point source efficiency spatial distribution, the position efficiency corresponding to each voxel is obtained.

[0103] In one embodiment, the point source position whose distance from the center position coordinates of each voxel is within a preset distance threshold range can be found from the point source efficiency spatial distribution according to the center position coordinates of each voxel. The distance threshold can be determined according to the size of the voxel. For example, when the voxel is in a cube shape, the distance threshold can be less than or equal to half the side length of each face of the cube in the voxel. Then, the point source efficiency is found from the point source efficiency spatial distribution according to the point source position found. For example, when at least one point source position is a point source position, the point source efficiency of the point source position can be directly used as the position efficiency. For another example, when at least one point source position includes multiple point source positions, the point source efficiencies of the multiple point source positions are interpolated (for example, the interpolation ratio or interpolation weight is calculated according to the distance to the center coordinate position) to obtain the position efficiency.

[0104] According to the embodiments of the present disclosure, when the passive efficiency calibration method of numerical integration is applied to calibrate the detection efficiency of the body source to be measured, the attenuation length required for use in the process can be quickly calculated, and the attenuation ratio of each voxel can be obtained based on the attenuation length and the material attenuation coefficient of the body source to be measured, and then the voxel efficiency of each voxel can be obtained based on the position efficiency and the attenuation ratio of each voxel. In this way, when the voxel efficiency of all voxels in the body source to be measured is obtained, the spatial distribution of the voxel efficiency of all voxels in the body source to be measured is obtained, and then by numerically integrating the voxel efficiency of all voxels in the body source to be measured, the operation efficiency of the calculation can be effectively improved and the operation time can be reduced while ensuring the error level of the calculation result.

[0105] According to some embodiments of the present disclosure, when calculating the attenuation length, for a coaxial axisymmetric volume source sample, a two-dimensional geometric relationship can be used to calculate the attenuation length, further saving calculation time. Correspondingly, for a non-coaxial axisymmetric volume source sample, a three-dimensional geometric relationship can be used to calculate the attenuation length, which can make the passive efficiency calibration method more widely used.

[0106] Figure 8 A schematic structural diagram of a gamma detector efficiency calibration device 800 based on numerical integration according to an embodiment of the present disclosure is shown.

[0107] like Figure 8As shown, the apparatus 800 may include a first acquisition module 810 , a voxelization module 820 , a matching module 830 , a second acquisition module 840 , a first processing module 850 and a numerical integration module 860 .

[0108] The first acquisition module 810 is used to acquire the spatial distribution of the point source efficiency of the gamma detector, which is information about how the detection efficiency of the gamma detector for a point source varies with the point source position of the point source. In one embodiment, the first acquisition module 810 may perform the operation S41 described above.

[0109] The voxelization module 820 is used to voxelize the volume source model of the volume source to be measured to obtain a plurality of voxels, wherein the volume source model is a closed polyhedron. In one embodiment, the voxelization module 820 may perform the operation S42 described above.

[0110] The matching module 830 is used to obtain the position efficiency corresponding to each voxel based on the matching of the position information of each voxel with the point source position in the point source efficiency spatial distribution, wherein the position information of each voxel is obtained based on the position information of the volume source model and the position of each voxel in the volume source model, and the position information of the volume source model is obtained according to the position of the volume source to be measured in space. In one embodiment, the matching module 830 can perform the operation S43 described above.

[0111] The second acquisition module 840 is used to acquire the distance from each voxel to the surface of the volume source model in the direction of the ray pointing from each voxel to the detection center of the gamma detector to obtain the attenuation length of each voxel. In one embodiment, the second acquisition module 840 may perform the operation S44 described above.

[0112] The first processing module 850 is used to obtain the attenuation ratio of each voxel based on the attenuation length of each voxel and the material attenuation coefficient of the volume source to be measured, and to obtain the voxel efficiency of each voxel based on the position efficiency and the attenuation ratio of each voxel. In one embodiment, the first processing module 850 can perform the operations S45 and S46 described above.

[0113] The numerical integration module 860 is used to process the voxel efficiency of multiple voxels based on the passive efficiency calibration method of numerical integration to obtain the detection efficiency of the gamma detector for the volume source to be detected. In one embodiment, the numerical integration module 860 can perform the operation S47 described above.

[0114] According to some embodiments of the present disclosure, the second acquisition module 840 includes a coaxial axisymmetric submodule. The coaxial axisymmetric submodule is used to calculate the attenuation length of each voxel in the two-dimensional plane where each voxel and the axis of symmetry are located by a two-dimensional geometric relationship when the volume source model is an axisymmetric model and the axis of symmetry coincides with the axis of symmetry of the gamma detector; wherein the detection center of the gamma detector is on the axis of symmetry of the gamma detector.

[0115] According to some embodiments of the present disclosure, the coaxial axisymmetric submodule is used to: determine the target two-dimensional plane based on the target voxel and the axis of symmetry, wherein the target voxel is any one of the multiple voxels; obtain the first position information of the target voxel in the target two-dimensional plane and the second position information of the detection center in the target two-dimensional plane; obtain the target angle information based on the angle between the target ray direction pointing from the first position information to the second position information and the predefined reference direction in the target two-dimensional plane; obtain the boundary position information of the surface of the volume source model in the target ray direction based on the position information and the target angle information of the volume source model; and obtain the attenuation length of the target voxel based on the boundary position information and the first position information. In one embodiment, the coaxial axisymmetric submodule can perform the operations S441 to S445 described above.

[0116] According to an embodiment of the present disclosure, the second acquisition module 840 further includes a non-coaxial axisymmetric submodule. The non-coaxial axisymmetric submodule is used to calculate the attenuation length of each voxel based on the three-dimensional geometric relationship between each voxel, the volume source model and the detection center in space when the volume source model is a non-axisymmetric model or the volume source model is an axisymmetric model but the symmetry axis does not coincide with the symmetry axis of the gamma detector.

[0117] The device 800 can realize reference Figure 4~Figure 7 The efficiency calibration method described is described in detail in the previous article and will not be repeated here.

[0118] According to an embodiment of the present disclosure, any multiple modules of the first acquisition module 810, the voxelization module 820, the matching module 830, the second acquisition module 840, the first processing module 850 and the numerical integration module 860 can be combined in one module, or any one of the modules can be split into multiple modules. Alternatively, at least part of the functions of one or more of these modules can be combined with at least part of the functions of other modules and implemented in one module. According to an embodiment of the present disclosure, at least one of the first acquisition module 810, the voxelization module 820, the matching module 830, the second acquisition module 840, the first processing module 850 and the numerical integration module 860 can be at least partially implemented as a hardware circuit, such as a field programmable gate array (FPGA), a programmable logic array (PLA), a system on a chip, a system on a substrate, a system on a package, an application specific integrated circuit (ASIC), or can be implemented by hardware or firmware such as any other reasonable way of integrating or packaging the circuit, or implemented in any one of the three implementation methods of software, hardware and firmware or in a suitable combination of any of them. Alternatively, at least one of the first acquisition module 810, the voxelization module 820, the matching module 830, the second acquisition module 840, the first processing module 850 and the numerical integration module 860 can be at least partially implemented as a computer program module, which can perform corresponding functions when the computer program module is executed.

[0119] Fig. 9 A schematic structural diagram of an electronic device suitable for implementing a gamma detector efficiency calibration method based on numerical integration according to various embodiments of the present disclosure is shown.

[0120] like Fig. 9 As shown, the electronic device 900 according to an embodiment of the present disclosure includes a processor 901, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 902 or a program loaded from a storage part 908 to a random access memory (RAM) 903. The processor 901 may include, for example, a general-purpose microprocessor (e.g., a CPU), an instruction set processor and / or a related chipset and / or a dedicated microprocessor (e.g., an application-specific integrated circuit (ASIC)), etc. The processor 901 may also include an onboard memory for caching purposes. The processor 901 may include a single processing unit or multiple processing units for performing different actions of the method flow according to an embodiment of the present disclosure.

[0121] In RAM 903, various programs and data required for the operation of electronic device 900 are stored. Processor 901, ROM 902 and RAM 903 are connected to each other via bus 904. Processor 901 performs various operations of the method flow according to the embodiment of the present disclosure by executing the program in ROM 902 and / or RAM 903. It should be noted that the program can also be stored in one or more memories other than ROM 902 and RAM 903. Processor 901 can also perform various operations of the method flow according to the embodiment of the present disclosure by executing the program stored in the one or more memories.

[0122] According to an embodiment of the present disclosure, the electronic device 900 may further include an input / output (I / O) interface 905, which is also connected to the bus 904. The electronic device 900 may further include one or more of the following components connected to the I / O interface 905: an input portion 906 including a keyboard, a mouse, etc.; an output portion 907 including a cathode ray tube (CRT), a liquid crystal display (LCD), etc., and a speaker, etc.; a storage portion 908 including a hard disk, etc.; and a communication portion 909 including a network interface card such as a LAN card, a modem, etc. The communication portion 909 performs communication processing via a network such as the Internet. A drive 910 is also connected to the I / O interface 905 as needed. A removable medium 911, such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, etc., is installed on the drive 910 as needed, so that a computer program read therefrom is installed into the storage portion 908 as needed.

[0123] The present disclosure also provides a computer-readable storage medium, which may be included in the device / apparatus / system described in the above embodiments; or may exist independently without being assembled into the device / apparatus / system. The above computer-readable storage medium carries one or more programs, and when the above one or more programs are executed, the method according to the embodiment of the present disclosure is implemented.

[0124] According to an embodiment of the present disclosure, a computer-readable storage medium may be a non-volatile computer-readable storage medium, for example, may include but is not limited to: a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof. In the present disclosure, a computer-readable storage medium may be any tangible medium containing or storing a program, which may be used by or in combination with an instruction execution system, an apparatus or a device. For example, according to an embodiment of the present disclosure, a computer-readable storage medium may include the ROM 902 and / or RAM 903 described above and / or one or more memories other than ROM 902 and RAM 903.

[0125] The embodiment of the present disclosure also includes a computer program product, which includes a computer program, and the computer program contains program code for executing the method shown in the flowchart. When the computer program product is run in a computer system, the program code is used to enable the computer system to implement the item recommendation method provided by the embodiment of the present disclosure.

[0126] The above functions defined in the system / device of the embodiment of the present disclosure are performed when the computer program is executed by the processor 901. According to the embodiment of the present disclosure, the system, device, module, unit, etc. described above can be implemented by a computer program module.

[0127] In one embodiment, the computer program may be based on a tangible storage medium such as an optical storage device, a magnetic storage device, etc. In another embodiment, the computer program may also be transmitted and distributed in the form of a signal on a network medium, and downloaded and installed through the communication part 909, and / or installed from a removable medium 911. The program code contained in the computer program may be transmitted using any appropriate network medium, including but not limited to: wireless, wired, etc., or any suitable combination of the above.

[0128] In such an embodiment, the computer program can be downloaded and installed from the network through the communication part 909, and / or installed from the removable medium 911. When the computer program is executed by the processor 901, the above functions defined in the system of the embodiment of the present disclosure are performed. According to the embodiment of the present disclosure, the system, device, means, module, unit, etc. described above can be implemented by a computer program module.

[0129] According to an embodiment of the present disclosure, the program code for executing the computer program provided by the embodiment of the present disclosure can be written in any combination of one or more programming languages. Specifically, these computing programs can be implemented using high-level process and / or object-oriented programming languages, and / or assembly / machine languages. Programming languages ​​include, but are not limited to, Java, C++, python, "C" language or similar programming languages. The program code can be executed entirely on the user computing device, partially on the user device, partially on the remote computing device, or entirely on the remote computing device or server. In the case of a remote computing device, the remote computing device can be connected to the user computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computing device (for example, using an Internet service provider to connect through the Internet).

[0130] The flow charts and block diagrams in the accompanying drawings illustrate the possible architecture, functions and operations of the systems, methods and computer program products according to various embodiments of the present disclosure. In this regard, each box in the flow chart or block diagram can represent a module, a program segment, or a part of a code, and the above-mentioned module, program segment, or a part of a code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram or flow chart, and the combination of the boxes in the block diagram or flow chart can be implemented with a dedicated hardware-based system that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0131] It will be appreciated by those skilled in the art that the features described in the various embodiments and / or claims of the present disclosure may be combined and / or combined in a variety of ways, even if such combinations and / or combinations are not explicitly described in the present disclosure. In particular, the features described in the various embodiments and / or claims of the present disclosure may be combined and / or combined in a variety of ways without departing from the spirit and teachings of the present disclosure. All of these combinations and / or combinations fall within the scope of the present disclosure.

[0132] The embodiments of the present disclosure are described above. However, these embodiments are only for illustrative purposes and are not intended to limit the scope of the present disclosure. Although the embodiments are described above separately, this does not mean that the measures in the various embodiments cannot be used in combination to advantage. The scope of the present disclosure is defined by the attached claims and their equivalents. Without departing from the scope of the present disclosure, those skilled in the art may make a variety of substitutions and modifications, which should all fall within the scope of the present disclosure.

Claims

1. A method for calibrating the efficiency of a gamma detector based on numerical integration, comprising: Acquire a point source efficiency spatial distribution of a gamma detector, wherein the point source efficiency spatial distribution is information on how the detection efficiency of the gamma detector for a point source varies with the point source position of the point source; voxelize a volume source model of a volume source to be measured to obtain a plurality of voxels, wherein the volume source model is a closed polyhedron; Based on the matching of the position information of each voxel with the point source position in the point source efficiency spatial distribution, the position efficiency corresponding to each voxel is obtained, wherein the position information of each voxel is obtained based on the position information of the volume source model and the position of each voxel in the volume source model, and the position information of the volume source model is obtained according to the position of the volume source to be measured in space; Acquire the distance from each voxel to the surface of the volume source model in the direction of the ray pointing from each voxel to the detection center of the gamma detector to obtain the attenuation length of each voxel; Based on the attenuation length of each voxel and the material attenuation coefficient of the volume source to be measured, obtaining the attenuation ratio of each voxel; Based on the position efficiency and the attenuation ratio of each voxel, a voxel efficiency of each voxel is obtained; The voxel efficiencies of the plurality of voxels are processed by a passive efficiency calibration method based on numerical integration to obtain the detection efficiency of the gamma detector for the volume source to be detected.

2. The method according to claim 1, wherein: The step of acquiring the distance from each voxel to the surface of the volume source model in the direction of the ray pointing from each voxel to the detection center of the gamma detector to obtain the attenuation length of each voxel comprises: When the volume source model is an axisymmetric model and the axis of symmetry coincides with the axis of symmetry of the gamma detector, the attenuation length of each voxel is calculated by a two-dimensional geometric relationship in a two-dimensional plane where each voxel and the axis of symmetry are located; wherein the detection center of the gamma detector is on the axis of symmetry of the gamma detector.

3. The method according to claim 2, wherein: When the volume source model is an axisymmetric model and the axis of symmetry coincides with the axis of symmetry of the gamma detector, in the two-dimensional plane where each voxel and the axis of symmetry are located, calculating the attenuation length of each voxel by a two-dimensional geometric relationship includes: Determine a target two-dimensional plane based on a target voxel and the symmetry axis, wherein the target voxel is any one of the multiple voxels; Acquire first position information of the target voxel in the target two-dimensional plane and second position information of the detection center in the target two-dimensional plane; Obtaining target angle information based on an angle between a target ray direction pointing from the first position information to the second position information and a predefined reference direction in the target two-dimensional plane; Based on the position information of the volume source model and the target angle information, obtaining the boundary position information of the surface of the volume source model in the direction of the target ray; and Based on the boundary position information and the first position information, an attenuation length of the target voxel is obtained.

4. The method according to claim 1, wherein: The step of acquiring the distance from each voxel to the surface of the volume source model in the direction of the ray pointing from each voxel to the detection center of the gamma detector to obtain the attenuation length of each voxel comprises: When the volume source model is a non-axisymmetric model or the volume source model is an axisymmetric model but the symmetry axis does not coincide with the symmetry axis of the gamma detector, the attenuation length of each voxel is calculated based on the three-dimensional geometric relationship between each voxel, the volume source model and the detection center in space.

5. The method according to claim 1, wherein: The matching of the position information of each voxel with the point source position in the point source efficiency spatial distribution to obtain the position efficiency corresponding to each voxel includes: Finding at least one point source position from the point source efficiency spatial distribution based on the position information of each voxel; and Based on the point source efficiency corresponding to the at least one point source position in the point source efficiency spatial distribution, the position efficiency corresponding to each voxel is obtained.

6. The method according to claim 5, wherein: The obtaining the position efficiency corresponding to each voxel based on the point source efficiency corresponding to the at least one point source position in the point source efficiency spatial distribution includes: When the at least one point source position is a point source position, the point source efficiency of the point source position is used as the position efficiency; or When the at least one point source position includes a plurality of point source positions, the point source efficiencies of the plurality of point source positions are interpolated to obtain the position efficiency.

7. The method according to claim 1, wherein: The spatial distribution of point source efficiency is represented by a grid or a fitting function.

8. The method according to claim 1, wherein: The passive efficiency calibration method based on numerical integration processes the voxel efficiency of the plurality of voxels to obtain the detection efficiency of the gamma detector for the volume source to be detected, comprising: The voxel efficiencies of the multiple voxels are integrated and averaged to obtain the detection efficiency of the gamma detector for the volume source to be detected.

9. A gamma detector efficiency calibration device based on numerical integration, comprising: A first acquisition module is used to acquire a spatial distribution of a point source efficiency of a gamma detector, wherein the spatial distribution of the point source efficiency is information on how the detection efficiency of the gamma detector for a point source varies with the point source position of the point source; A voxelization module, used for voxelizing a volume source model of a volume source to be measured to obtain a plurality of voxels, wherein the volume source model is a closed polyhedron; A matching module, configured to obtain the position efficiency corresponding to each voxel based on the matching of the position information of each voxel with the point source position in the point source efficiency spatial distribution, wherein the position information of each voxel is obtained based on the position information of the volume source model and the position of each voxel in the volume source model, and the position information of the volume source model is obtained according to the position of the volume source to be measured in space; A second acquisition module is used to acquire the distance from each voxel to the surface of the volume source model in the direction of the ray pointing from each voxel to the detection center of the gamma detector, so as to obtain the attenuation length of each voxel; A first processing module, configured to obtain an attenuation ratio of each voxel based on the attenuation length of each voxel and the material attenuation coefficient of the volume source to be measured, and to obtain a voxel efficiency of each voxel based on the position efficiency and the attenuation ratio of each voxel; and The numerical integration module is used to process the voxel efficiency of the plurality of voxels based on a passive efficiency calibration method of numerical integration to obtain the detection efficiency of the gamma detector for the volume source to be detected.

10. An electronic device, comprising: one or more processors; a memory for storing one or more computer programs, The one or more processors execute the one or more computer programs to implement the steps of the method according to any one of claims 1 to 8.

11. A computer-readable storage medium having a computer program or instruction stored thereon, wherein: When the computer program or instruction is executed by a processor, the steps of the method according to any one of claims 1 to 8 are implemented.

12. A computer program product comprising a computer program or instructions, wherein: When the computer program or instruction is executed by a processor, the steps of the method according to any one of claims 1 to 8 are implemented.

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