Method for calculating maximum SAR value of region of interest, and readable storage medium and computer device

Abstract

The present application is applicable to the field of electromagnetic radiation. Provided are a method and apparatus for calculating the maximum SAR value of a region of interest, and a computer-readable storage medium and a computer device. The method comprises the following steps: using complex function expression (1) to describe SAR values of a region of interest, wherein SAR(x)=u(x)+iv(x), x∈D (1); and solving for the maximum value among the absolute values of SARs of the region of interest by means of region decomposition combined with linear programming. By means of the present application, the precision of the calculation of the maximum SAR value can be improved, and compared with a conventional method for directly solving for the maximum value, the precision is improved by one order of magnitude.

Description

Calculation method of SAR maximum value in area of ​​interest, readable storage medium and computer device Technical Field

[0001] The present application relates to the field of electromagnetic radiation, and in particular to a method, apparatus, computer-readable storage medium, and computer equipment for calculating the SAR maximum value of an area of ​​interest. Background Art

[0002] In the field of electromagnetic radiation, researchers use SAR (Specific Absorption Rate) to measure the amount of radiation absorbed by human tissue. The increasing use of wireless devices has also increased the amount of radiation absorbed by human tissue. The SAR value is a commonly used attribute to measure the absorbed energy, which can determine the amount of radiation absorbed by human tissue. The SAR value directly reflects the damage caused by electromagnetic radiation to a living organism. Generally speaking, the higher the SAR value for a particular area, the greater the damage caused by electromagnetic radiation to that area. Within a given region of interest, the maximum SAR value is generally used as an important indicator of the impact of electromagnetic radiation on the area of ​​interest.

[0003] A typical application scenario is a head model for receiving and making calls on a mobile phone. This model studies how the human head absorbs antenna radiation waves and the resulting temperature rise. In this model, the region of interest is the smallest enclosing cuboid of the human head. The geometry of the human head is defined by IEEE, IEC, and CENELEC standards.

[0004] Generally speaking, the SAR value in the region of interest can be obtained based on existing testing technology and solution algorithms. However, due to the limitations of computer storage devices, only N sample points {x p ,1≤p≤N}, expressed as: {SAR(x p ),x p ∈ region of interest D, 1≤p≤N}, where N is a finite positive integer. A simple and direct method for calculating the maximum SAR value in region of interest D based on the SAR values ​​corresponding to these N samples is to take the maximum absolute value of the SAR values ​​corresponding to these N samples. The disadvantage of this method is that the accuracy of calculating the maximum SAR value is insufficient. Let Δ be the distance between adjacent sample points. The accuracy of this direct maximum value algorithm is on the order of O(Δ).

[0005] Summary of the Invention

[0006] The purpose of the present application is to provide a method, apparatus, computer-readable storage medium, and computer equipment for calculating the SAR maximum value of a region of interest, which can improve the accuracy of calculating the SAR maximum value.

[0007] In a first aspect, the present application provides a method for calculating the maximum value of the SAR in an interest region, including the following steps:

[0008] S101. Describe the SAR value in the interest region using the complex function formula (1): Sar(x) = u(x) + iv(x), x ∈ D (1)

[0009] where u(x), v(x) ∈ R represent continuous and smooth real - valued functions in three - dimensional space, i represents an imaginary unit, D represents the cuboid interest region, which is described by the cuboid D := {x: x(j) ∈ [l j , u j , j = 1, 2, 3}, the interest region is the smallest - enclosing cuboid of the human body's interested part, x(1), x(2), and x(3) respectively represent the coordinates of point x in the x - axis, y - axis, and z - axis directions, l j and u j represent real numbers, satisfying: l1 < u1, where l1 is the minimum value of the coordinates of the cuboid D in the x - axis direction, u1 is the maximum value of the coordinates of the cuboid D in the x - axis direction, l2 < u2, where l2 is the minimum value of the coordinates of the cuboid D in the y - axis direction, u2 is the maximum value of the coordinates of the cuboid D in the y - axis direction, l3 < u3, where l3 is the minimum value of the coordinates of the cuboid D in the z - axis direction, and u3 is the maximum value of the coordinates of the cuboid D in the z - axis direction;

[0010] S102. Solve for the maximum value of the absolute value of the SAR within the interest region through region decomposition combined with linear programming:

[0011] max x∈D |Sar(x)| (3), where the symbol |.| represents taking the absolute value of a complex number.

[0012] In a second aspect, the present application provides a device for calculating the maximum value of the SAR in an interest region, including:

[0013] A description module for describing the SAR value in the interest region using the complex function formula (1): Sar(x) = u(x) + iv(x), x ∈ D (1)

[0014] where u(x), v(x) ∈ R represent continuous and smooth real - valued functions in three - dimensional space, i represents an imaginary unit, D represents the cuboid interest region, which is described by the cuboid D := {x: x(j) ∈ [l j S101. Describe the SAR value in the interest region using the complex function formula (1): Sar(x) = u(x) + iv(x), x ∈ D (1) j , j = 1, 2, 3}, the interest region is the smallest - enclosing cuboid of the human body's interested part, x(1), x(2), and x(3) respectively represent the coordinates of point x in the x - axis, y - axis, and z - axis directions, l j and u jDenote real numbers, satisfying: l1 < u1, where l1 is the minimum value of the coordinates of the cuboid D in the x-axis direction, u1 is the maximum value of the coordinates of the cuboid D in the x-axis direction, l2 < u2, where l2 is the minimum value of the coordinates of the cuboid D in the y-axis direction, u2 is the maximum value of the coordinates of the cuboid D in the y-axis direction, l3 < u3, where l3 is the minimum value of the coordinates of the cuboid D in the z-axis direction, and u3 is the maximum value of the coordinates of the cuboid D in the z-axis direction;

[0015] A solving module, configured to solve the maximum value of the absolute value of SAR in the region of interest by combining region decomposition with linear programming:

[0016] max x∈D |Sar(x)| (3), where the symbol |.| represents taking the absolute value of a complex number.

[0017] In a third aspect, the present application provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the steps of the method for calculating the maximum value of SAR in the region of interest as described above are implemented.

[0018] In a fourth aspect, the present application provides a computer device, including:

[0019] One or more processors;

[0020] A memory; and

[0021] One or more computer programs, where the processor and the memory are connected through a bus. The one or more computer programs are stored in the memory and are configured to be executed by the one or more processors. When the processor executes the computer program, the steps of the method for calculating the maximum value of SAR in the region of interest as described above are implemented. Beneficial effects

[0022] In the present application, since the maximum value of the absolute value of SAR in the region of interest is solved by combining region decomposition with linear programming. Therefore, the accuracy of calculating the maximum value of SAR can be improved, and the accuracy can reach O(Δ 2 ). Therefore, in the case of the same number of samples, the accuracy of the present application can be improved by one order of magnitude, or under the requirement of the same accuracy, the number of samples can be reduced by one order of magnitude. Description of the drawings

[0023] FIG. 1 is a flowchart of a method for calculating the maximum value of SAR in the region of interest provided by an embodiment of the present application.

[0024] FIG. 2 is a functional module block diagram of a device for calculating the maximum value of SAR in the region of interest provided by an embodiment of the present application.

[0025] FIG. 3 is a specific structural block diagram of a computer device provided by an embodiment of the present application. Detailed implementation manners

[0026] In order to make the objectives, technical solutions and beneficial effects of the present application clearer and more understandable, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0027] In order to illustrate the technical solutions described in the present application, specific embodiments will be used for illustration below.

[0028] Please refer to FIG. 1, which is a flowchart of a method for calculating the maximum value of SAR in an interest region provided by an embodiment of the present application. In this embodiment, the method for calculating the maximum value of SAR in the interest region is mainly exemplified by being applied to a computer device. The method for calculating the maximum value of SAR in an interest region provided by an embodiment of the present application includes the following steps:

[0029] S101. Describe the SAR value in the interest region using the complex function formula (1): Sar(x) = u(x) + iv(x), x ∈ D (1)

[0030] Where, u(x), v(x) ∈ R represent continuous and smooth real functions in three-dimensional space, i represents a pure imaginary number, D represents the cuboid interest region, which is described by the cuboid D: = {x: x(j) ∈ [l j , u j , j = 1, 2, 3}, the interest region is the smallest enclosing cuboid of the human interest part, x(1), x(2) and x(3) respectively represent the coordinates of point x in the x-axis, y-axis and z-axis directions, l j and u j represent real numbers, satisfying: l1 < u1, where l1 is the minimum value of the coordinate of the cuboid D in the x-axis direction, u1 is the maximum value of the coordinate of the cuboid D in the x-axis direction, l2 < u2, where l2 is the minimum value of the coordinate of the cuboid D in the y-axis direction, u2 is the maximum value of the coordinate of the cuboid D in the y-axis direction, l3 < u3, where l3 is the minimum value of the coordinate of the cuboid D in the z-axis direction, and u3 is the maximum value of the coordinate of the cuboid D in the z-axis direction;

[0031] S102. Solve for the maximum value of the absolute value of SAR in the interest region through region decomposition combined with linear programming:

[0032] max x∈D |Sar(x)| (3), where the symbol |.| represents taking the absolute value of a complex number.

[0033] In an embodiment of the present application, the SAR value in the interest region is N sample points {x measured in the interest regionp SAR value on ∈D,1≤p≤N}, expressed as formula (2): SAR(x p )=u(x p )+iv(x p ),1≤p≤N (2).

[0034] In one embodiment of the present application, S102 specifically includes the following steps:

[0035] S1021, according to N sample points {x p ∈D,1≤p≤N} Perform spline function interpolation on SAR(.) in the cuboid D to obtain the function value and partial derivative value of SAR(.) at any point in the cuboid D;

[0036] S1022. Perform regional decomposition on the cuboid D: Among them D p :={x:x(k)∈[x p (k)-Δ k ,x p (k)+Δ k ],k=1,2,3},1≤p≤N; where Δ k >0, k=1,2,3 are positive integers, Δ1, Δ2 and Δ3 represent the region decomposition step size in the x-axis, y-axis and z-axis directions respectively;

[0037] S1023, in D p Perform a first-order Taylor expansion on |Sar(x)|: where c p is a three-dimensional complex vector, d p is a complex number, and the function Sar(.) is used in x p The partial derivative value at is determined;

[0038] S1024, using linear programming to solve D p The maximum value of |Sar(x)| in :

[0039] Solved That is D p The maximum value of |Sar(x)|;

[0040] S1025, according to the solution Find the maximum absolute value of SAR in the cuboid D:

[0041] Referring to FIG. 2, the apparatus for calculating the maximum SAR value of the region of interest provided by an embodiment of the present application may be a computer program or a piece of program code running on a computer device. For example, the apparatus for calculating the maximum SAR value of the region of interest is an application software; the apparatus for calculating the maximum SAR value of the region of interest can be used to execute the corresponding steps in the method for calculating the maximum SAR value of the region of interest provided by an embodiment of the present application. The apparatus for calculating the maximum SAR value of the region of interest provided by an embodiment of the present application includes:

[0042] A description module 11, configured to describe the SAR value in the region of interest by using the complex function formula (1); Sar(x) = u(x) + iv(x), x ∈ D (1)

[0043] where u(x), v(x) ∈ R represent continuous and smooth real functions in three-dimensional space, i represents a pure imaginary number, D represents the cuboid region of interest, which is described by the cuboid D := {x: x(j) ∈ [l j , u j , j = 1, 2, 3}, the region of interest is the smallest enclosing cuboid of the human body's region of interest, x(1), x(2), and x(3) respectively represent the coordinates of point x in the x-axis, y-axis, and z-axis directions, l j and u j represent real numbers, satisfying: l1 < u1, where l1 is the minimum value of the coordinates of the cuboid D in the x-axis direction, u1 is the maximum value of the coordinates of the cuboid D in the x-axis direction, l2 < u2, where l2 is the minimum value of the coordinates of the cuboid D in the y-axis direction, u2 is the maximum value of the coordinates of the cuboid D in the y-axis direction, l3 < u3, where l3 is the minimum value of the coordinates of the cuboid D in the z-axis direction, and u3 is the maximum value of the coordinates of the cuboid D in the z-axis direction;

[0044] A solving module 12, configured to solve the maximum value of the absolute value of SAR within the region of interest by combining regional decomposition with linear programming:

[0045] max x∈D |Sar(x)| (3), where the symbol |.| represents taking the absolute value of a complex number.

[0046] The apparatus for calculating the maximum SAR value of the region of interest provided by an embodiment of the present application and the method for calculating the maximum SAR value of the region of interest provided by an embodiment of the present application belong to the same concept. The specific implementation process is detailed in the full text of the specification and will not be repeated here.

[0047] An embodiment of the present application provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, it implements the steps of the method for calculating the maximum SAR value of the region of interest provided by an embodiment of the present application.

[0048] Figure 3 shows a specific structural block diagram of a computer device provided in an embodiment of the present application. A computer device 100 includes: one or more processors 101, a memory 102, and one or more computer programs, wherein the processors 101 and the memory 102 are connected via a bus. The one or more computer programs are stored in the memory 102 and are configured to be executed by the one or more processors 101. When the processor 101 executes the computer program, the steps of the method for calculating the maximum SAR value of the region of interest provided in an embodiment of the present application are implemented.

[0049] In this application, the maximum absolute value of SAR in the region of interest is solved by combining regional decomposition with linear programming. Therefore, the accuracy of calculating the maximum value of SAR can be improved, and the accuracy can reach O(Δ 2 ), so with the same number of samples, the accuracy of the present application can be improved by one order of magnitude, or with the same accuracy requirement, the number of samples can be reduced by one order of magnitude.

[0050] It should be understood that each step in each embodiment of the present application is not necessarily performed in sequence according to the order indicated by the step numbers. Unless clearly stated herein, the execution of these steps does not have strict order restrictions, and these steps can be performed in other orders. Moreover, in each embodiment, at least a portion of steps may include a plurality of sub-steps or a plurality of stages, and these sub-steps or stages are not necessarily performed at the same time, but can be performed at different times, and the execution order of these sub-steps or stages is not necessarily performed in sequence, but can be performed in turn or alternately with at least a portion of other steps or the sub-steps or stages of other steps.

[0051] Those skilled in the art will appreciate that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program. The program can be stored in a non-volatile computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0052] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0053] The above embodiments merely illustrate several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make various modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A method for calculating the maximum value of SAR in the region of interest, characterized in that, it includes the following steps: S101. Describe the SAR value in the region of interest by using the complex function formula (1); Sar(x) = u(x) + iv(x), x ∈ D (1) where \(u(x), v(x)\in R\) represent continuous and smooth real-valued functions in three-dimensional space, \(i\) represents the pure imaginary number, and \(D\) represents the region of interest of the cuboid, which is described by the cuboid \(D:=\{x:x^{(j)}\in [l j ,u j , j = 1, 2, 3\}\), and the region of interest is the smallest enclosing cuboid of the human body's region of interest. \(x^{(1)}, x^{(2)}\), and \(x^{(3)}\) respectively represent the coordinates of point \(x\) in the \(x\)-axis, \(y\)-axis, and \(z\)-axis directions. \(l j and \(u j represent real numbers, satisfying: \(l 1 <u 1 , where \(l 1 is the minimum value of the coordinates of the cuboid \(D\) in the \(x\)-axis direction, and \(u 1 is the maximum value of the coordinates of the cuboid \(D\) in the \(x\)-axis direction. \(l 2 <u 2 , where \(l 2 is the minimum value of the coordinates of the cuboid \(D\) in the \(y\)-axis direction, and \(u 2 is the maximum value of the coordinates of the cuboid \(D\) in the \(y\)-axis direction. \(l 3 <u 3 , where \(l 3 is the minimum value of the coordinates of the cuboid \(D\) in the \(z\)-axis direction, and \(u 3 is the maximum value of the coordinates of the cuboid \(D\) in the \(z\)-axis direction; S102. Solve for the maximum value of the absolute value of SAR in the region of interest by combining region decomposition with linear programming: max x∈D |Sar(x)| (3), where the symbol |.| represents taking the absolute value of a complex number.

2. The method according to claim 1, characterized in that, The SAR values in the region of interest are the SAR values measured at N sample points {x p ∈ D, 1 ≤ p ≤ N} in the region of interest, expressed as in Equation (2): SAR(x p ) = u(x p ) + iv(x p ), 1 ≤ p ≤ N (2).

3. The method according to claim 2, characterized in that, S102 specifically includes the following steps: S1021. Interpolate the SAR(.) in the cuboid D by spline function according to N sample points {x p ∈ D, 1 ≤ p ≤ N} in the region of interest to obtain the function value and partial derivative value of SAR(.) at any point in the cuboid D; S1022. Perform regional decomposition on the cuboid D: Among which D p : = {x: x(k) ∈ [x p (k) - Δ k , x p (k) + Δ k , k = 1, 2, 3}, 1 ≤ p ≤ N; where Δ k > 0, k = 1, 2, 3 are positive integers, Δ 1 , Δ 2 and Δ 3 respectively represent the regional decomposition step sizes in the x-axis, y-axis, and z-axis directions; S1023. Perform a first-order Taylor expansion of |Sar(x)| in D p : where c p is a three-dimensional complex vector, and d p is a complex number, which is determined by the partial derivative value of the function Sar(.) at x p . S1024. Solve for the maximum value of |Sar(x)| in D using linear programming p among Solved That is D p The maximum value of |Sar(x)| in S1025. According to the solved Find the maximum value of the absolute value of SAR within the cuboid D:

4. A device for calculating the maximum value of SAR in the region of interest, characterized in that, it includes: A description module, configured to describe the SAR value in the region of interest by using the complex function formula (1); Sar(x) = u(x) + iv(x), x ∈ D (1) Among them, u(x), v(x) ∈ R represent continuous and smooth real-valued functions in three-dimensional space, i represents the pure imaginary number, and D represents the region of interest of the cuboid, which is described by the cuboid D := {x: x(j) ∈ [l j , u j , j = 1, 2, 3}, where the region of interest is the smallest enclosing cuboid of the human body's region of interest, x(1), x(2), and x(3) respectively represent the coordinates of point x in the x-axis, y-axis, and z-axis directions, l j and u j represent real numbers, satisfying: l 1 < u 1 , where l 1 is the minimum value of the coordinates of the cuboid D in the x-axis direction, and u 1 is the maximum value of the coordinates of the cuboid D in the x-axis direction, l 2 < u 2 , where l 2 is the minimum value of the coordinates of the cuboid D in the y-axis direction, and u 2 is the maximum value of the coordinates of the cuboid D in the y-axis direction, l 3 < u 3 , where l 3 is the minimum value of the coordinates of the cuboid D in the z-axis direction, and u 3 is the maximum value of the coordinates of the cuboid D in the z-axis direction; A solving module, configured to solve for the maximum value of the absolute value of SAR in the region of interest by combining region decomposition with linear programming: max x∈D |Sar(x)| (3), where the symbol |.| represents taking the absolute value of a complex number.

5. A computer-readable storage medium storing a computer program, characterized in that, when the computer program is executed by a processor, it implements the steps of the method for calculating the maximum value of SAR in the region of interest according to any one of claims 1 to 3.

6. A computer device, including: One or more processors; A memory; and One or more computer programs, the processor and the memory are connected through a bus, wherein the one or more computer programs are stored in the memory and are configured to be executed by the one or more processors. Characterized in that, when the processor executes the computer program, it implements the steps of the method for calculating the maximum value of SAR in the region of interest according to any one of claims 1 to 3.

Images