A matrix radiation dose probe

Abstract

This invention discloses a matrix-type radiation dose detector, comprising: a detection module and a back-end processing module; the detection module is used to receive gamma rays and generate corresponding photocurrent signals, including N×M probe units, each probe unit including a pre-collimator, a high-precision CsI scintillator, and a photomultiplier tube installed sequentially from top to bottom; the probe units are arranged in an N×M matrix, where N and M are both positive integers greater than 1; the back-end processing module includes: a single-channel pulse amplitude analyzer, an FPGA, and an MCU; each photomultiplier tube is respectively connected to one of the single-channel pulse amplitude analyzers, all of the single-channel pulse amplitude analyzers are electrically connected to the FPGA, and the FPGA is electrically connected to the MCU; this invention can effectively scan specific organs of patients receiving internal radiotherapy.

Description

Technical Field

[0001] This invention relates to the field of nuclear radiation monitoring technology, and more specifically to a matrix-type radiation dose detector. Background Technology

[0002] In recent years, with the continuous development of related technologies in the field of nuclear medicine, radiotherapy has gradually become one of the commonly used methods for the clinical treatment of malignant tumors. Statistics show that approximately 1.8 million new cases of tumors are diagnosed in my country each year, and a total of 1.3 million malignant tumor patients require radiotherapy. While early conventional radiotherapy techniques could treat most tumors, they also caused significant damage to surrounding normal tissues and were difficult to control in terms of dose distribution within the irradiation field. Internal radiotherapy, as a new type of radiotherapy, has the advantages of high targeting, significant therapeutic effects, and good sustainability. Internal radiotherapy involves implanting radioactive drug sources into the patient's body through surgery, intravenous injection, or ingestion or swallowing pills. The radioactive drugs are absorbed and concentrated by internal organs, killing tumor cells through close-range, targeted irradiation. It plays an irreplaceable role, particularly in the treatment of thyroid cancer, prostate cancer, cervical cancer, and malignant tumor lymph node metastases.

[0003] Therefore, how to provide a detection matrix radiation dose detector that can scan specific organs of patients receiving internal radiotherapy is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] In view of this, the present invention provides a matrix-type radiation dose detector that can effectively scan specific organs of patients receiving internal radiotherapy.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A matrix-type radiation dose detector includes: a detection module and a back-end processing module;

[0007] The detection module is used to receive gamma rays and generate corresponding photocurrent signals. It includes N×M probe units. Each probe unit includes a pre-collimator, a high-precision CsI scintillator, and a photomultiplier tube installed from top to bottom. The probe units are arranged in an N×M matrix, where N and M are both positive integers greater than 1.

[0008] The back-end processing module includes: a single-channel pulse amplitude analyzer, an FPGA, and an MCU; each photomultiplier tube is connected to one of the single-channel pulse amplitude analyzers, all of the single-channel pulse amplitude analyzers are electrically connected to the FPGA, and the FPGA is electrically connected to the MCU.

[0009] The single-channel pulse amplitude analyzer is used to classify the electrical pulse signals corresponding to the photocurrent signal according to the magnitude of the signal amplitude and record the number of signals in each category.

[0010] The FPGA is used to integrate and encapsulate independent pulse count rates;

[0011] The MCU is used to convert each independent pulse count rate according to the calibrated conversion formula according to the instructions of the host computer, to obtain N×M absorbed dose rates, and to obtain accurate absorbed measurement data through interpolation algorithm.

[0012] Preferably, the pre-collimator is a hollow lead columnar structure with a square cross-section, a thickness of 1.5 mm, a side length of 1 cm, and a height of 1.5 cm.

[0013] Preferably, the high-precision CsI scintillator has a cubic structure with a side length of 1 cm.

[0014] Preferably, the photomultiplier tube is a columnar structure with a square cross-section, a height of 3mm, and a side length of 1cm.

[0015] Preferably, the detection module includes a detection panel and a housing. The detection panel has a perforated structure adapted to the probe unit, and the number of perforated structures is the same as the number of probe units. The probe unit is mounted on the detection panel. The housing is a cavity structure, and the detection panel is mounted on the housing as the top plate. One side of the housing is provided with an aluminum upper cover plate and an aluminum lower cover plate. The housing is also provided with wiring terminals and a bracket. The wiring terminals include a 485 data interface and a 220V power interface. The bracket is used to hang the detector.

[0016] Preferably, the back-end processing module further includes a pulse amplifier, a scaler, and a high-voltage power supply unit. Each photomultiplier tube is connected to a pulse amplifier, each pulse amplifier is connected to a single-channel pulse amplitude analyzer, each single-channel pulse amplitude analyzer is connected to a scaler, the scaler is electrically connected to the FPGA, and each photomultiplier tube is electrically connected to the high-voltage power supply unit.

[0017] The high-voltage power supply unit supplies power to the photomultiplier tube, the pulse amplifier converts the photocurrent signal generated by the photomultiplier tube into an electrical pulse signal and amplifies and shapes it, and the calibrator performs D / A conversion, converting the analog quantity into a pulse count of a recognizable digital quantity and outputting it to the FPGA.

[0018] Preferably, the MCU communicates with the FPGA via a CAN bus.

[0019] Preferably, the interpolation algorithm includes the following:

[0020] S1. Establish a coordinate system, divide it into P×P grids, and take any point (x, y) as the interpolation point, with the corresponding absorbed dose value being D. x，y ;

[0021] S2. Draw a line parallel to the x-axis or y-axis passing through the interpolation point (x, y), and obtain the coordinates of the projection points on the parallel line and the two diagonal lines.

[0022] S3. Calculate the absorbed dose fraction of the projection point coordinates using linear interpolation formulas:

[0023] S4. Calculate the absorbed dose at the point (x, y) to be interpolated using a linear interpolation formula based on the absorbed dose score;

[0024] For the first region, where a line parallel to the x-axis is drawn passing through the interpolation point (x, y), the absorbed dose fraction is:

[0025]

[0026]

[0027] The absorbed dose is:

[0028]

[0029] For the second region, where a line parallel to the y-axis is drawn passing through the interpolation point (x, y), the absorbed dose fraction is:

[0030]

[0031]

[0032] The absorbed dose is:

[0033]

[0034] For the third region, where a line parallel to the y-axis is drawn passing through the interpolation point (x, y), the absorbed dose fraction is:

[0035]

[0036]

[0037] The absorbed dose is:

[0038]

[0039] For the fourth region, where a line parallel to the x-axis is drawn passing through the interpolation point (x, y), the absorbed dose fraction is:

[0040]

[0041]

[0042] The absorbed dose is:

[0043]

[0044] As can be seen from the above technical solution, compared with the prior art, the present invention discloses a matrix radiation dose detector. The matrix radiation dose detector adopts a matrix structure design, with CsI scintillators and photomultipliers as core detector components. It can effectively realize the scanning detection of specific organs of patients receiving internal radiotherapy, which makes it convenient for doctors to accurately grasp the distribution of radiopharmaceutical activity and residual dose in a certain organ of the patient's body. Furthermore, a pre-collimator is installed at the front end of each detector to reduce the interference of gamma ray scattering, making the detector more accurate and better able to assist in the precision treatment of nuclear medicine. Attached Figure Description

[0045] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0046] Figure 1 The attached figure is a schematic diagram of the overall frame of a matrix-type radiation dose detector provided in an embodiment of the present invention;

[0047] Figure 2 The attached figure is a schematic diagram of the specific structure of a matrix radiation dose detector with a square cross-section, according to an embodiment of the present invention.

[0048] Figure 3 The attached figure is a schematic diagram of the specific structure of a matrix radiation dose detector with a circular cross-section in an embodiment of the present invention.

[0049] Figure 4 The attached figure is a schematic diagram of the specific structure of a matrix-type radiation dose detector provided in an embodiment of the present invention;

[0050] Figure 5 The attached figure is a schematic diagram of the specific structure of a matrix-type radiation dose detector provided in an embodiment of the present invention;

[0051] Figure 6 The attached figure is a schematic diagram of the interpolation algorithm partitioning in a matrix radiation dose detector provided by an embodiment of the present invention;

[0052] Among them, a-probe unit, a1-pre-collimator, a2-high-precision CsI scintillator, a3-photomultiplier tube, b-lower cover plate, c-upper cover plate, d-terminal block, e-hanger. Detailed Implementation

[0053] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0054] This invention discloses a matrix-type radiation dose detector, such as... Figure 1 As shown, it includes: a detection module and a back-end processing module;

[0055] The detection module is used to receive the corresponding photocurrent signal generated by gamma rays, and includes N×M probe units a, such as Figure 2 As shown, each probe unit a includes a pre-collimator a1, a high-precision CsI scintillator a2, and a photomultiplier tube a3, which are installed sequentially from top to bottom; the probe unit a is arranged in an N×M matrix, where N and M are both positive integers greater than 1;

[0056] The back-end processing module includes: a single-channel pulse amplitude analyzer, an FPGA, and an MCU; each photomultiplier tube a3 is connected to a single-channel pulse amplitude analyzer, all single-channel pulse amplitude analyzers are electrically connected to the FPGA, and the FPGA is electrically connected to the MCU;

[0057] A single-channel pulse amplitude analyzer is used to classify the electrical pulse signals corresponding to the photocurrent signal according to the magnitude of the signal amplitude and record the number of signals in each category.

[0058] FPGA is used to integrate and encapsulate independent pulse count rates;

[0059] The MCU is used to convert each independent pulse count rate according to the calibrated conversion formula according to the instructions of the host computer, to obtain N×M absorbed dose rates, and to obtain accurate absorbed measurement data through interpolation algorithm.

[0060] It should be noted that:

[0061] The conversion formula is y = ax + b, where y is the absorbed dose and x is the pulse count. By measuring a set (usually 20 to 40 sets of data) of absorbed dose and pulse count, the parameters a and b are obtained using the least squares method. Then, the absorbed dose is obtained by predicting other pulse counts using a and b.

[0062] To further implement the above technical solution, the pre-collimator a1 is a lead hollow columnar structure with a square cross-section, a thickness of 1.5mm, a side length of 1cm, and a height of 1.5cm.

[0063] It should be noted that:

[0064] Figure 2 The diagram shows the structure of a single detector. The front collimator a1 is mainly designed with a lead square column structure with a thickness of 1.5mm and a length of 1cm. This size can ensure accurate reception of γ-rays at the corresponding position, while filtering out interference from nearby scattered γ-rays.

[0065] To further implement the above technical solution, the high-precision CsI scintillator a2 is a cubic structure with a side length of 1cm.

[0066] To further implement the above technical solution, the photomultiplier tube a3 is a columnar structure with a square cross-section, a height of 3mm, and a side length of 1cm.

[0067] It should be noted that:

[0068] The pre-collimator a1, the high-precision CsI scintillator a2, and the photomultiplier tube a3 can all be cylindrical, i.e., have a circular cross-section, such as... Figure 3 As shown, the settings can be adjusted as needed in practical applications.

[0069] To further implement the above technical solutions, such as Figure 4 As shown, the detection module includes a detection panel and a housing. The detection panel has a perforated structure that matches the probe unit a, and the number of perforated structures is the same as the number of probe units a. The probe unit a is mounted on the detection panel. The housing is a hollow structure, and the detection panel is mounted on the housing as the top plate. An aluminum upper cover plate c and an aluminum lower cover plate b are provided on one side of the housing. The housing also has a wiring terminal d and a bracket e. The wiring terminal d includes a 485 data interface and a 220V power interface. The bracket e is used to hang the detector.

[0070] It should be noted that:

[0071] The matrix-type radiation dose detector can be mounted on a three-dimensional motion platform and can be driven by a multi-axis controller to move up and down, forward and backward, and left and right. This enables in-depth three-dimensional scanning and detection of specific organs of patients receiving internal radiotherapy, allowing doctors to accurately grasp the distribution of radiopharmaceutical activity and residual dose in a patient's body.

[0072] Furthermore, the housing is made of aluminum and is used to encapsulate probe unit a to form a matrix detector array.

[0073] To further implement the above technical solution, the back-end processing module also includes a pulse amplifier, a scaler, and a high-voltage power supply unit. Each photomultiplier tube a3 is connected to a pulse amplifier, and each pulse amplifier is connected to a single-channel pulse amplitude analyzer. Each single-channel pulse amplitude analyzer is connected to a scaler, and the scaler is electrically connected to the FPGA. All photomultiplier tubes are electrically connected to the high-voltage power supply unit.

[0074] The high-voltage power supply unit supplies power to the photomultiplier tube a3, the pulse amplifier converts the photocurrent signal generated by the photomultiplier tube a3 into an electrical pulse signal and amplifies and shapes it, and the scaler is used to complete the D / A conversion, converting the analog quantity into a pulse count of a recognizable digital quantity and outputting it to the FPGA.

[0075] To further implement the above technical solution, the MCU communicates with the FPGA via the CAN bus.

[0076] It should be noted that:

[0077] Considering the average size of human organs, in this embodiment, both N and M are preferably set to 10, that is, the matrix radiation dose detector is configured with 100 detectors. The detection width range of this size covers the size of the major human organs. Furthermore, the matrix radiation dose detector is designed with 10 probe units a in each row and column to ensure effective coverage and detection accuracy of the detection data. After the multi-channel radiation detector completes one human body scan, it can acquire 10×10 grid data, totaling 100 grids. Through data interpolation, the dose distribution map of the human organ range can be finally obtained.

[0078] In practical applications, N and M can be further configured as needed. For example, N can be set to 1 and M to 13, such as... Figure 5 As shown.

[0079] In this embodiment, a silicon photomultiplier tube a3 is used to achieve the above work. The FPGA mainly uses the Stratix series chip manufactured by Altera, which has high processing performance and can ensure the real-time performance of data processing and conversion. The MCU uses the STM32F407 series microcontroller manufactured by STMicroelectronics.

[0080] The overall working principle of this embodiment is as follows:

[0081] In the matrix-type radiation dose detector, gamma rays first pass through the pre-collimator a1 of each probe unit a to filter out interference from nearby scattered rays, ensuring that the rays entering probe unit a all come from the ray beam in front of probe unit a. After the gamma rays enter the CsI scintillator, they react with the dopant material in the scintillator to produce fluorescence. The fluorescence is converted and amplified by the photomultiplier tube a3 to generate a photocurrent signal, which is then sent to the back-end processing module for further amplification and signal processing. In the back-end processing module, 100 high-voltage power supply modules provide high voltage to the photomultiplier tubes (A3) of the 100 probes, ensuring the normal operation of the photomultiplier tubes A3. The current signal generated by the photomultiplier tubes A3 is converted into an electrical pulse signal by a pulse amplifier, and the electrical pulse signal is amplified and shaped. The converted electrical pulse signal is processed by a single-channel pulse amplitude analyzer, which classifies the pulse signal according to its amplitude and records the number of signals in each category. Next, a calibrator performs D / A conversion, converting the analog quantity into a recognizable digital quantity, i.e., pulse count. Then, the FPGA performs comprehensive processing to complete the integration and encapsulation of the 100 independent pulse count rates. The MCU is the interaction medium between the detector and the host computer control system, realizing the interaction with the host computer commands and the transmission of data. After receiving the data acquisition command from the host computer, the MCU communicates with the FPGA via the CAN bus, converts the 100 pulse count rates according to the conversion formula after calibration of each independent probe data, converts them into the corresponding absorbed dose rate, and encapsulates them, sending them to the host computer for comprehensive analysis and display processing.

[0082] To further implement the above technical solution, the interpolation algorithm includes the following:

[0083] S1. Establish a coordinate system, divide it into P×P grids, and take any point (x, y) as the interpolation point, with the corresponding absorbed dose value being D. x，y ;

[0084] S2. Draw a parallel line to the x-axis passing through the point to be interpolated (x, y). The coordinates of the projection points on the parallel line and the two diagonal lines are (y, y) and (Py, y), respectively.

[0085] S3. Calculate the absorbed dose fraction of the projection point coordinates using linear interpolation formulas:

[0086] S4. Calculate the absorbed dose at the point (x, y) to be interpolated using a linear interpolation formula based on the absorbed dose score;

[0087] For the first region, where a line parallel to the x-axis is drawn passing through the point (x, y) to be interpolated, the absorbed dose fraction is:

[0088]

[0089]

[0090] The absorbed dose is:

[0091]

[0092] For the second region, where a line parallel to the y-axis is drawn passing through the point (x, y) to be interpolated, the absorbed dose fraction is:

[0093]

[0094]

[0095] The absorbed dose is:

[0096]

[0097] For the third region, where a line parallel to the y-axis is drawn passing through the point to be interpolated (x, y), the absorbed dose fraction is:

[0098]

[0099]

[0100] The absorbed dose is:

[0101]

[0102] For the fourth region, where a line parallel to the x-axis is drawn passing through the point (x, y) to be interpolated, the absorbed dose fraction is:

[0103]

[0104]

[0105] The absorbed dose is:

[0106]

[0107] It should be noted that:

[0108] In the above embodiment, the multi-channel radiation dose detection with N set to 10 can acquire 100 radiation dose data in 10×10 scans. However, since the monitoring data on the 10×10 grid are mainly discrete points, it can only achieve centimeter-level resolution and cannot achieve millimeter-level precision. In order to better reflect the gradient effect of radiation dose distribution of a certain human organ, this embodiment also adopts a four-zone quadratic linear interpolation algorithm, which obtains the corresponding value by calculating the output value of the four adjacent points above, below, left, and right of the interpolation.

[0109] The algorithm described above will be illustrated with examples below:

[0110] S1. Set the grid where the interpolation point is located to extend horizontally to the right and vertically to the top along the left side, with the horizontal axis being the x-axis and the vertical axis being the y-axis. Divide the four sides of the grid where the interpolation point is located (hereinafter referred to as the grid) into 100 equal parts, i.e., set M to 100, which can form a 100×100 cell matrix. The scale of each cell is 1, and the actual size it represents is 50mm / 100=0.5mm.

[0111] The point where the x-axis and y-axis intersect is the origin, and the minimum value of the coordinate axis is 0. Along the horizontal x-axis, because the grid is divided into 100 equal parts, the maximum value is 100. Along the vertical y-axis, it is also divided into 100 equal parts, so the maximum value is also 100.

[0112] The projection values ​​of each point in a 100×100 cell (hereinafter referred to as the cell) onto the horizontal and vertical axes are defined as the coordinates of that point. For example, the coordinates of the four vertices of the grid from the top left along the clockwise direction are (0, 100), (100, 100), (100, 0) and (0, 0), and the coordinates of the center point are (50, 50).

[0113] If the coordinates of a point are (x, y), then its absorbed dose value is D. x，y The absorbed dose values ​​at the four vertices of the grid are denoted as D, starting from the top left and proceeding clockwise. 0,100 D 100,100 D 100，0 and D 0,0 The absorbed dose at the center point is

[0114] The grid is divided into four regions. Starting from the four vertices of the grid, connect the two diagonally opposite vertices along the diagonal with straight lines, thus dividing the grid into four isosceles triangular regions. The extent of each of the four regions is as follows: Figure 6 As shown:

[0115] The coordinate range for region 1 is: 0 ≤ x < 50, 0 ≤ y ≤ x; 50 <x≤100,0≤y≤100-x

[0116] The coordinate range for zone 2 is: 0 ≤ x ≤ 50, x <y<100-x

[0117] The coordinate range for zone 3 is 50. <x≤100,100-x<y<x

[0118] The coordinate range for region 4 is: 0 ≤ x < 50, 100 - x ≤ y ≤ 100; 50 <x≤100,x≤y≤100

[0119] Among them, the first region is taken as the interpolation point D. x,y The calculation process of the algorithm is illustrated using an example. The interpolation calculation process for other regions is the same as that for region 1.

[0120] S2. Draw a line parallel to the x-axis passing through the point to be interpolated (x, y). The coordinates of the projection points on the two diagonal lines of this line are (y, y) and (100-y, y), respectively.

[0121] S3. Calculate the absorbed dose value D at coordinates (y, y) and (100-y, y) using a linear interpolation formula. (y , y) and D (100-y，y) Since the three sets of coordinates (0, 0), (100, 100), and (100, 0) form a right isosceles triangle, and the other three sets of coordinates (0, 0), (y, y), and (y, 0) also form a triangle sharing a vertex with the previous right isosceles triangle, according to the theorem of similar triangles, the distance from the origin (0, 0) to (x, y) is proportional to the distance projected onto the x-axis of the two points. Similarly, the distance from the origin (0, 0) to (100, 100) is also proportional to the distance projected onto the x-axis of the two points. Therefore, without calculating the lengths of each point on the diagonal, we can directly use the projected distances onto the x-axis to replace them, resulting in:

[0122]

[0123]

[0124] S4. Then, using the already calculated D... y，y and D 100-y，y The absorbed dose at the interpolation point (x, y) is calculated using a linear interpolation formula.

[0125] If necessary, S2-S4 can be repeated to calculate the absorbed dose value of each interpolation point belonging to Zone 1. Finally, the absorbed dose values ​​obtained from the interpolation of the four zones can be summarized to facilitate the generation of a radiation dose heatmap.

[0126] For the above-mentioned four-zone quadratic linear interpolation algorithm, this invention uses two diagonals to divide the grid into four regions. Each region is an isosceles triangle formed by the grid center point and two adjacent grid vertices. The actual interpolation value is determined by the gradient change law of the two hypotenuse sides of the triangle and the horizontal gradient change law parallel to the base of the triangle, thus eliminating the uncertainty of the influence of the four vertices on the interpolation point.

[0127] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0128] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A matrix-type radiation dose detector, characterized in that, include: Detection module and back-end processing module; The detection module is used to receive gamma rays and generate corresponding photocurrent signals. It includes N×M probe units. Each probe unit includes a pre-collimator, a high-precision CsI scintillator, and a photomultiplier tube installed from top to bottom. The probe units are arranged in an N×M matrix, where N and M are both positive integers greater than 1. The pre-collimator is a hollow lead columnar structure with a square cross-section, a thickness of 1.5 mm, a side length of 1 cm, and a height of 1.5 cm. The back-end processing module includes: a single-channel pulse amplitude analyzer, an FPGA, and an MCU; each photomultiplier tube is connected to one of the single-channel pulse amplitude analyzers, all of the single-channel pulse amplitude analyzers are electrically connected to the FPGA, and the FPGA is electrically connected to the MCU. The single-channel pulse amplitude analyzer is used to classify the electrical pulse signals corresponding to the photocurrent signal according to the magnitude of the signal amplitude and record the number of signals in each category. The FPGA is used to integrate and encapsulate independent pulse count rates; The MCU is used to convert each independent pulse count rate according to the calibrated conversion formula according to the instructions of the host computer, to obtain N×M absorbed dose rates, and to obtain accurate absorbed measurement data through a four-zone quadratic linear interpolation algorithm. The four-zone quadratic linear interpolation algorithm is as follows: S1. Establish a coordinate system, divide it into P×P grids, and take any point (x, y) as the interpolation point, with the corresponding absorbed dose value being D. x，y ; S2. Draw a line parallel to the x-axis or y-axis passing through the interpolation point (x, y), and obtain the coordinates of the projection points on the two diagonal lines of the drawn line. S3. Calculate the absorbed dose fraction of the projection point coordinates using linear interpolation formulas: S4. Calculate the absorbed dose at the point (x, y) to be interpolated using a linear interpolation formula based on the absorbed dose score; The grid is divided into four regions using two diagonals. Each region consists of an isosceles triangle formed by the grid center point and two adjacent grid vertices. The actual interpolation value is determined by the gradient variation of the two hypotenuses of the triangle and the lateral gradient variation parallel to the base of the triangle, thus eliminating the uncertainty of the influence of the four vertices on the interpolation point. For the first region, where a line parallel to the x-axis is drawn passing through the interpolation point (x, y), the absorbed dose fraction is: ； ； The absorbed dose is: ； For the second region, where a line parallel to the y-axis is drawn passing through the interpolation point (x, y), the absorbed dose fraction is: ； ； The absorbed dose is: ； For the third region, where a line parallel to the y-axis is drawn passing through the interpolation point (x, y), the absorbed dose fraction is: ； ； The absorbed dose is: ； For the fourth region, where a line parallel to the x-axis is drawn passing through the interpolation point (x, y), the absorbed dose fraction is: ； ； The absorbed dose is: 。 2. A matrix-type radiation dose detector according to claim 1, characterized in that, The high-precision CsI scintillator has a cubic structure with a side length of 1 cm.

3. A matrix-type radiation dose detector according to claim 1, characterized in that, The photomultiplier tube is a columnar structure with a square cross-section, a height of 3mm, and a side length of 1cm.

4. A matrix-type radiation dose detector according to claim 1, characterized in that, The detection module includes a detection panel and a housing. The detection panel has a perforated structure adapted to the probe unit, and the number of perforated structures is the same as the number of probe units. The probe unit is mounted on the detection panel. The housing is a hollow structure, and the detection panel is mounted on the housing as the top plate. One side of the housing has an aluminum upper cover plate and an aluminum lower cover plate. The housing also has wiring terminals and a bracket. The wiring terminals include a 485 data interface and a 220V power interface. The bracket is used to hang the detector.

5. A matrix-type radiation dose detector according to claim 1, characterized in that, The back-end processing module also includes a pulse amplifier, a scaler, and a high-voltage power supply unit. Each photomultiplier tube is connected to a pulse amplifier, each pulse amplifier is connected to a single-channel pulse amplitude analyzer, each single-channel pulse amplitude analyzer is connected to a scaler, the scaler is electrically connected to the FPGA, and each photomultiplier tube is electrically connected to the high-voltage power supply unit. The high-voltage power supply unit supplies power to the photomultiplier tube, the pulse amplifier converts the photocurrent signal generated by the photomultiplier tube into an electrical pulse signal and amplifies and shapes it, and the calibrator performs D / A conversion, converting the analog quantity into a pulse count of a recognizable digital quantity and outputting it to the FPGA.

6. A matrix-type radiation dose detector according to claim 1, characterized in that, The MCU communicates with the FPGA via a CAN bus.

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