Method for evaluating effect of time interference stimulation

Abstract

The invention relates to an effect evaluation method for time interference stimulation. The method comprises the following steps: inputting a lead field matrix, a feasible solution matrix, a target point coordinate, a preset stimulation range and nuclear magnetic image data with electric field value distribution; calculating an envelope space electric field distribution matrix; calculating a brain total electric field; calculating a total prime number based on the envelope space electric field distribution matrix; calculating a total electric field in the limited area and a total electric field in the non-limited area based on the envelope space electric field distribution matrix, the nuclear magnetic image data with the electric field value distribution, the target point coordinates and a preset stimulation range; based on the envelope space electric field distribution matrix, the target point coordinates and a preset stimulation range, calculating the number of voxels in the limited area and the number of voxels in the non-limited area; and calculating the average electric field of the brain, the average electric field in the limited area and the average electric field in the non-limited area. Through the setting, the quality of a plurality of feasible solutions in time interference stimulation can be better evaluated and measured.

Description

Technical Field

[0001] The present invention relates to the technical field of transcranial electrical stimulation, and in particular to a method for evaluating the effect of temporal interference stimulation. Background Art

[0002] Temporal interferometric stimulation (TIS) is a type of transcranial electrical stimulation (TES). TES involves placing electrodes on the scalp and stimulating brain nuclei through discharges, thereby treating mental illness. However, while conventional TES typically only effectively stimulates the cerebral cortex, TIS can effectively stimulate deep brain nuclei.

[0003] By accurately evaluating the effects of temporal interferometric stimulation, we can gain a deeper understanding of how different electrode placement patterns and current levels influence treatment outcomes. This helps researchers and clinicians develop personalized treatment plans tailored to each patient's specific circumstances, such as disease severity and brain structural characteristics.

[0004] Currently, evaluating the effectiveness of temporal interferometric stimulation (TIS) is typically done manually. Different research institutions and clinical sites often design their own evaluation metrics and methods based on their own experience and needs. This results in a lack of comparability between data and prevents the formation of systematic research results. Manual, computer-assisted, specialized calculations are not only time-consuming and labor-intensive, but also prone to errors due to the complexity and repetitiveness of manual operations. Furthermore, the lack of unified evaluation criteria makes it difficult to determine which approach is truly more effective, significantly hindering the development of TIS technology. Consequently, the existing technology lacks a comprehensive, universal evaluation method for the effectiveness of TIS. Summary of the Invention

[0005] In order to solve the above-mentioned defects, the present invention proposes a method for evaluating the effect of time interference stimulation.

[0006] The technical solution adopted by the present invention is a method for evaluating the effect of temporal interference stimulation, the method comprising:

[0007] S100, input the lead field matrix, feasible solution matrix, target coordinates, preset stimulation range, and MRI image data with electric field value distribution;

[0008] S200, calculating the envelope space electric field distribution matrix of the time interference stimulation based on the lead field matrix and the feasible solution matrix;

[0009] S300, calculating the total electric field of the brain based on the envelope space electric field distribution matrix and the nuclear magnetic resonance imaging data with electric field value distribution;

[0010] Based on the envelope space electric field distribution matrix, calculate the overall prime number;

[0011] Based on the envelope space electric field distribution matrix, the MRI image data with electric field value distribution, the target coordinates, and the preset stimulation range, the total electric field in the limited area and the total electric field in the unrestricted area are calculated;

[0012] Based on the envelope space electric field distribution matrix, the target coordinates, and the preset stimulation range, the number of voxels in the restricted area and the number of voxels in the unrestricted area are calculated;

[0013] S400, calculating the average electric field of the brain, the average electric field in the limited area, and the average electric field in the unlimited area, wherein:

[0014] Average electric field of the brain = total electric field of the brain / total prime number,

[0015] Average electric field in the defined area = total electric field in the defined area / number of voxels in the defined area,

[0016] Average electric field in the unconfined area = total electric field in the unconfined area / number of voxels in the unconfined area;

[0017] S500 , based on the result calculated in S400 , obtaining an effect evaluation result of the time interference stimulation.

[0018] Furthermore, the S200 specifically includes:

[0019] S210, reconstructing the feasible solution matrix into two current matrices;

[0020] S220, multiplying the two current matrices with the lead field matrix to obtain two high-frequency electric field spatial distribution matrices;

[0021] S230. Apply the Grossman formula to calculate the two high-frequency electric field spatial distribution matrices to obtain the envelope spatial electric field distribution matrix of the time interference stimulation.

[0022] Furthermore, the S400 further includes: calculating an average electric field ratio, where the average electric field ratio = average electric field in the defined area / average electric field in the brain.

[0023] Furthermore, the S100 further includes: inputting a stimulation threshold;

[0024] The S300 further includes:

[0025] Based on the envelope space electric field distribution matrix and the stimulation threshold, the total number of voxels exceeding the threshold is calculated;

[0026] Based on the envelope space electric field distribution matrix, the target coordinates, the preset stimulation range, and the stimulation threshold, the number of voxels exceeding the threshold in the limited area is calculated;

[0027] The S400 further includes: calculating the focusing property, where the focusing property = the number of voxels exceeding the threshold in the defined area / the total number of voxels exceeding the threshold.

[0028] Furthermore, after S500, the following steps are further included:

[0029] S600, calculating the effect of conventional transcranial electrical stimulation;

[0030] S700, comparing the effects of temporal interferometric stimulation and conventional transcranial electrical stimulation;

[0031] The S600 specifically includes:

[0032] S610, calculating the spatial electric field distribution matrix of common transcranial electrical stimulation based on the lead field matrix and the feasible solution matrix;

[0033] S620, based on the spatial electric field distribution matrix of common transcranial electrical stimulation, the nuclear magnetic resonance imaging data with electric field value distribution, the target coordinates, and the preset stimulation range, calculate the average electric field in the common transcranial electrical stimulation limited area and the average electric field in the common transcranial electrical stimulation unrestricted area,

[0034] The focusing of the common transcranial electrical stimulation is calculated based on the spatial electric field distribution matrix of the common transcranial electrical stimulation, the target coordinates, the preset stimulation range, and the stimulation threshold.

[0035] Furthermore, the S700 specifically includes: calculating the relative change rate of the effect of the time interference stimulation and the effect of the ordinary transcranial electrical stimulation.

[0036] Furthermore, the calculation of the relative change rate of the stimulation effect of the temporal interferometric stimulation and the stimulation effect of the ordinary transcranial electrical stimulation specifically includes:

[0037] Calculate the electric field increase of the target point under temporal interferometric stimulation, where the electric field increase of the target point under temporal interferometric stimulation = (the average electric field within the limited area of temporal interferometric stimulation - the average electric field within the limited area of ordinary transcranial electrical stimulation) / the average electric field within the limited area of ordinary transcranial electrical stimulation; and / or

[0038] Calculate the electric field increase of the non-target target during time-interference stimulation, where the electric field increase of the non-target target during time-interference stimulation = (the average electric field in the non-limited area during time-interference stimulation - the average electric field in the non-limited area during ordinary transcranial electrical stimulation) / the average electric field in the non-limited area during ordinary transcranial electrical stimulation; and / or

[0039] The improvement in temporal interferometric stimulation focusing is calculated as follows: improvement in temporal interferometric stimulation focusing = (temporal interferometric stimulation focusing - ordinary transcranial electrical stimulation focusing) / ordinary transcranial electrical stimulation focusing.

[0040] Furthermore, the S610 specifically includes:

[0041] S611, reconstructing the feasible solution matrix into two current matrices;

[0042] S612. Add the two current matrices to obtain the spatial electric field distribution matrix of ordinary transcranial electrical stimulation.

[0043] Furthermore, the S100 further includes: inputting a gridded three-dimensional model;

[0044] The step S700 further includes:

[0045] S800 , based on the gridded three-dimensional model and the difference between the stimulation effect of the temporal interferometric stimulation and the stimulation effect of the common transcranial electrical stimulation, a difference rendering image is generated as an effect evaluation result of the temporal interferometric stimulation.

[0046] Furthermore, after S800, the following steps are further included:

[0047] S910, based on the gridded three-dimensional model, calculating the data resolution, the total volume of the head model, the maximum unit volume of the head model, the minimum unit volume of the head model, the average unit volume of the head model, and the median unit volume of the head model;

[0048] S920 , based on the result calculated in S910 , verify the effect evaluation results of the time interference stimulation obtained in S500 and S800 .

[0049] Compared with the prior art, the present invention has the following beneficial effects:

[0050] 1. The method for evaluating the effect of temporal interference stimulation in the present invention provides comprehensive and objective data support for the evaluation of the effect of temporal interference stimulation by calculating multiple quantitative indicators. Researchers and clinicians no longer rely solely on subjective experience judgment, but can accurately understand the stimulation effects under different electrode arrangements and current size combinations based on these specific numerical values, so as to more scientifically select appropriate stimulation schemes. Multi-dimensional indicator calculations help users analyze the stimulation effects from different angles. Standardized indicator calculation methods are conducive to the comparison and communication of results between different studies. Based on this method, researchers can conduct comparative experiments more conveniently, explore the impact of different factors on the effect of temporal interference stimulation, promote the further development of temporal interference stimulation technology in the fields of neuroscience research and clinical treatment, and accelerate the research and development and application of new technologies.

[0051] 2. The purpose of the present invention is to be able to better evaluate and measure the quality of multiple feasible solutions in time interference stimulation, and to enable users to more easily compare the effect differences of the same solution in different electrical stimulation methods. At the same time, the present invention can obtain the above content through a one-click program to avoid repeated manual operations. The time interference stimulation evaluation calculation method provided by the present invention effectively improves the efficiency of users in evaluating the effects between different feasible solutions, and the evaluation indicators are more complete and comprehensive. The comparison method of time interference stimulation and ordinary transcranial electrical stimulation provided by the present invention can clearly compare the effect differences of the same feasible solution between time interference stimulation and ordinary transcranial electrical stimulation, meeting actual needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] The present invention is described in detail below with reference to the embodiments and accompanying drawings, in which:

[0053] Figure 1 This is a flow chart of the method for evaluating the effect of temporal interference stimulation;

[0054] Figure 2 This is a difference rendering. DETAILED DESCRIPTION

[0055] To make the objectives, technical solutions, and advantages of the present invention more apparent, embodiments of the present invention will be described in further detail below with reference to the accompanying drawings. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar components or components having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0056] On the one hand, the electrode arrangement and corresponding current size of temporal interferometric stimulation often have countless feasible solutions for the same target point, but each feasible solution has multiple different evaluation dimensions. Therefore, there is no truly optimal solution. Users need to select the appropriate feasible solution based on the dimensions they need. Currently, users can only rely on themselves to select the appropriate solution from the numerous feasible solutions based on the dimensions of their own specific needs. However, this process not only consumes a lot of time and energy, but is also easily affected by subjective factors and lacks objectivity and scientificity. In actual operation, users often find it difficult to fully consider all dimensions, easily miss important information, and then make wrong choices, unable to fully realize the therapeutic effect of temporal interferometric stimulation, which seriously hinders the widespread application and development of temporal interferometric stimulation technology in clinical and scientific research fields.

[0057] Therefore, the present invention proposes a method for evaluating the effect of temporal interference stimulation, which can better evaluate and measure the quality of multiple feasible solutions in temporal interference stimulation, effectively improve the efficiency of users in evaluating the effects between different feasible solutions, and the evaluation indicators are more complete and comprehensive.

[0058] In one embodiment, a method for evaluating the effect of temporal interference stimulation is described in detail. Figure 1 , the method comprising:

[0059] S100, input the lead field matrix, feasible solution matrix, target coordinates, preset stimulation range, and nuclear magnetic resonance imaging data with electric field value distribution.

[0060] Specifically, the user inputs the subject's MRI data, gender and age information, and target coordinates into the transcranial electrical stimulation positioning simulation software. During the calculation process, the transcranial electrical stimulation positioning simulation software will generate a gridded three-dimensional model and lead field matrix based on the subject's MRI data after brain tissue segmentation, and output multiple feasible solutions and MRI data with electric field value distribution.

[0061] The lead field matrix provides the three-dimensional basic electric field distribution for each electrode at the head model grid points. Its dimensions are typically M×N×3, where M represents the number of electrodes, N represents the number of head model grid points, and 3 corresponds to the x, y, and z directions in three-dimensional space. The lead field matrix records the contribution of each electrode to the electric field at each location in space. It serves as the basic data for subsequent electric field calculations and includes information about physical properties such as electrode position and tissue conductivity.

[0062] The feasible solution matrix defines the current parameters and electrode position configuration. Its size is 6×1, with the first and second dimensions corresponding to the current magnitudes of the first and second pairs of electrodes, respectively, and the last four dimensions representing the positions of the four electrodes. The feasible solution matrix determines the current input and spatial layout of the electrodes.

[0063] The target coordinates are determined using the MNI coordinate space and are used to define the center position of a defined area. They are key parameters for calculating indicators such as focality and determine the brain area to be analyzed.

[0064] The preset stimulation range defines the radius or range of the area in millimeters. The user defines the focus range based on research or treatment needs, clarifies the spatial size of the defined area, and affects the calculation of indicators such as the average electric field within the defined area.

[0065] Magnetic resonance imaging data with electric field value distribution is essentially a matrix. The size of the matrix is the number of voxels in the xyz axis. Each unit represents a voxel, and the matrix value is the electric field value of the corresponding voxel. The target coordinates can be converted into matrix index subscripts through affine transformation.

[0066] S200. Based on the lead field matrix and the feasible solution matrix, calculate the envelope spatial electric field distribution matrix of the temporal interferometric stimulation. This matrix reflects the spatial electric field distribution of the temporal interferometric stimulation and serves as an important foundation for subsequent calculations. For example, if a person's brain is divided into several equal blocks, an X×Y×Z matrix can be constructed. The median value of the matrix corresponds to the electric field value of one of the blocks. Here, "block" refers to the "voxel" of indices a to h. The target coordinates are in a three-dimensional spatial coordinate system and need to be converted into matrix index coordinates through an affine transformation.

[0067] S300: Calculate the total brain electric field based on the envelope space electric field distribution matrix and the MRI data with electric field value distribution. Since the matrix values represent the electric field values of each voxel, the total electric field can be obtained by summing them up. This step is crucial for calculating the average brain electric field, reflecting the sum of the electric fields across the entire brain region under stimulation.

[0068] Based on the envelope space electric field distribution matrix, the total prime number is calculated. By analyzing the envelope space electric field distribution matrix, the number of voxels in the entire space is determined. The total prime number is another important parameter for calculating the average electric field in the brain.

[0069] Based on the envelope space electric field distribution matrix, the MRI data with electric field value distribution, the target coordinates, and the preset stimulation range, the total electric field in the restricted area and the total electric field in the unrestricted area are calculated. Based on the envelope space electric field distribution matrix, the target coordinates, and the preset stimulation range, the number of voxels in the restricted area and the number of voxels in the unrestricted area are calculated.

[0070] Based on a nuclear magnetic resonance image (matrix) with electric field distribution, the matrix's "limited region" can be found using the aforementioned index subscripts and the user-entered stimulation range. This operation is implemented using the numpy library. The user enters the target coordinates and the stimulation range, and a matrix mask is generated with the target coordinates and the stimulation range as the radius. This mask is the electric field distribution matrix for the user's area of interest. Summing this mask matrix yields the total electric field within the limited region.

[0071] Based on the target coordinates and the preset stimulation range, a defined region is identified within the envelope space electric field distribution matrix and the MRI data with the electric field value distribution. The electric field values of all voxels within the defined region are then summed to obtain the total electric field within the defined region, and the number of voxels within the defined region is counted. The total electric field within the undefined region is calculated by subtracting the total electric field within the defined region from the total brain electric field, and the number of voxels within the undefined region is calculated by subtracting the number of voxels within the defined region from the total number of voxels. These data provide the necessary conditions for calculating the average electric field within the defined region and the average electric field within the undefined region.

[0072] S400, calculating the average electric field of the brain, the average electric field in the restricted area, and the average electric field in the unrestricted area.

[0073] The average brain electric field = total brain electric field / total number of voxels. The average brain electric field (index a) reflects the average electric field strength of the entire brain area when stimulated, and can measure the overall level of stimulation from a macro perspective. The average brain electric field is the total electric field divided by the total number of voxels in the brain (note that the total number of voxels here is not X×Y×Z. X×Y×Z is a cube, and the brain is irregular. The total number of voxels in the brain can be obtained by summing the non-zero voxels in the statistical matrix. The value of 0 usually represents the background, and the non-zero value represents the brain).

[0074] The average electric field in the defined area = the total electric field in the defined area / the number of voxels in the defined area. The average electric field in the defined area (indicator b) focuses on the target area and reflects the stimulation intensity of the specific target, which is crucial for evaluating the stimulation effect on the target target.

[0075] The average electric field within the unrestricted area = the total electric field within the unrestricted area / the number of voxels within the unrestricted area. The average electric field within the unrestricted area (indicator c) is used to assess the intensity of stimulation in non-target areas and helps determine the specificity of stimulation, that is, the degree of targeting of the target area.

[0076] S500 , based on the result calculated in S400 , obtaining an effect evaluation result of the time interference stimulation.

[0077] By combining the above-calculated indicators, such as the average brain electric field, the average electric field within the restricted area, and the average electric field within the unrestricted area, the effectiveness of temporal interferometric stimulation can be evaluated from different perspectives. For example, by comparing the average electric field within the restricted area with the average electric field within the unrestricted area, the degree of focus of the stimulation on the target area can be assessed; the average brain electric field can be used to understand the overall stimulation intensity level. In other embodiments, the results calculated in S400 can also be weighted, normalized, or other operations to obtain a more scientific evaluation result of the effectiveness of temporal interferometric stimulation.

[0078] The method for evaluating the effect of time interference stimulation in this embodiment provides comprehensive and objective data support for the evaluation of the effect of time interference stimulation by calculating multiple quantitative indicators. Researchers and clinicians no longer rely solely on subjective experience judgment, but can accurately understand the stimulation effects under different electrode arrangements and current size combinations based on these specific values, so as to more scientifically select appropriate stimulation schemes. Multi-dimensional indicator calculations help users analyze the stimulation effects from different angles. Standardized indicator calculation methods are conducive to the comparison and communication of results between different studies. Based on this method, researchers can conduct comparative experiments more conveniently, explore the impact of different factors on the effect of time interference stimulation, promote the further development of time interference stimulation technology in the fields of neuroscience research and clinical treatment, and accelerate the research and development and application of new technologies.

[0079] The above calculations, such as voxels and average electric fields, can be calculated using an electric field distribution matrix. In other embodiments, they can also be calculated using a gridded three-dimensional model. The gridded three-dimensional model is essentially a more complex matrix. Since calculations using the electric field distribution matrix are simpler, calculations using the electric field distribution matrix are used in implementation.

[0080] In a more specific embodiment, the S200 specifically includes:

[0081] S210. Reconstruct the feasible solution matrix into two current matrices. Specifically, for envelope field calculations with temporal interferometric stimulation, reconstruct the feasible solution matrix into two new matrices with the electrode index position equal to 2 × the current magnitude and the non-index position equal to 0. In this way, the information about electrode current and position in the feasible solution matrix is converted into a matrix form that can be directly used in subsequent calculations, preparing for the calculation of the high-frequency electric field generated by the electrode.

[0082] S220. Multiply the two current matrices with the lead field matrix to obtain two high-frequency electric field spatial distribution matrices. Specifically, the two new matrices are multiplied with the lead field matrix to obtain the two electrodes' native high-frequency electric field spatial distribution matrices. The matrix multiplication process is essentially to calculate the distribution of the two electrodes' native high-frequency electric fields in space based on the current and position information of the electrodes and the electric field contribution relationship reflected by the lead field matrix, and obtain two high-frequency electric field spatial distribution matrices. This step establishes the connection from the electrode current and position to the spatial electric field distribution, providing basic data for the subsequent calculation of the envelope electric field.

[0083] S230. Apply the Grossman formula to calculate the two high-frequency electric field spatial distribution matrices to obtain the envelope spatial electric field distribution matrix of the time interference stimulation.

[0084] The Grossman formula is as follows:

[0085]

[0086] in, is the envelope electric field, is a space vector, is the electric field of the first set of electrodes, is the electric field of the second set of electrodes, α is The final result is the envelope space electric field distribution matrix of the temporal interference stimulus.

[0087] Based on the magnitude relationship and angle between the two high-frequency electric field vectors, different calculations are performed according to the formula to ultimately obtain the envelope spatial electric field distribution matrix of the temporal interferometric stimulation. This matrix reflects the distribution of the low-frequency modulated electric field generated by temporal interferometric stimulation in space and serves as an important foundation for evaluating the effects of temporal interferometric stimulation. Subsequent calculations of the total brain electric field and the total electric field within a defined area rely on this matrix.

[0088] Users' evaluation of feasible solutions is not a single process. Some may require higher focus, others a higher average electric field, some a stimulation range of 3cm^3, and still others prefer the smallest possible stimulation range. Some of these metrics can conflict with each other, for example, improving focus can reduce the average electric field. Therefore, a more comprehensive set of evaluation methods and metrics is needed for user reference.

[0089] In one embodiment, S400 further includes calculating an average electric field ratio, where the average electric field ratio = the average electric field within the defined area / the average electric field in the brain. The average electric field ratio (indicator d) reflects the relative relationship between the electric field strength within the defined area and the average electric field strength across the entire brain. It can intuitively demonstrate the relative strength of the electric field in the target area and further assist in determining the degree of focus of the stimulation on the target area.

[0090] In one embodiment, the S100 further includes: inputting a stimulation threshold.

[0091] The stimulation threshold is the user-defined threshold for electric field activation. The default value is 0.25 V / m, but it can be customized. It is the critical value for determining whether brain nuclei are activated and is used to calculate metrics such as focusing. Due to the characteristics of cell membranes, the stimulation threshold must be exceeded to effectively stimulate the target neurons. Literature generally considers this value to be 0.25 V / m, and the software uses this value by default. The user can also change the stimulation threshold.

[0092] The S300 further includes:

[0093] Based on the envelope space electric field distribution matrix and the stimulation threshold, the total number of voxels exceeding the threshold is calculated. Based on the previously calculated envelope space electric field distribution matrix, the electric field value of each voxel is compared with the input stimulation threshold. The number of voxels with electric field values exceeding the stimulation threshold is counted to obtain the total number of voxels exceeding the threshold. This value reflects the total number of voxels in the entire brain space whose electric field strength reaches a level sufficient to activate neurons.

[0094] Based on the envelope space electric field distribution matrix, target coordinates, preset stimulation range, and stimulation threshold, the number of voxels exceeding the threshold in the defined area is calculated. Combining the envelope space electric field distribution matrix, target coordinates, preset stimulation range, and stimulation threshold, the defined area is first determined based on the target coordinates and preset stimulation range. Then, within this area, the number of voxels with electric field values exceeding the stimulation threshold is counted, i.e., the number of voxels exceeding the threshold in the defined area. This value reflects the number of voxels in the target area that can effectively activate neurons.

[0095] S400 further includes calculating focus, where focus = number of voxels exceeding a threshold within a defined area / total number of voxels exceeding a threshold. Focus (index e) measures the concentration of the stimulus within the target area. A higher focus indicates a more concentrated effect of the stimulus within the target area and a lower impact on surrounding non-target areas.

[0096] Horizontally speaking, users may need to compare the difference between time interference stimulation and ordinary transcranial electrical stimulation, such as transcranial alternating current stimulation, for the same feasible solution in order to select a more appropriate stimulation method. The present invention also provides a comparison between time interference stimulation and transcranial alternating current stimulation or transcranial direct current stimulation to further optimize the effect evaluation method of time interference stimulation. For the comparison between time interference stimulation and ordinary transcranial electrical stimulation, the envelope spatial electric field distribution matrix of time interference stimulation can be subtracted from the spatial electric field distribution matrix of ordinary transcranial electrical stimulation to obtain a difference matrix, and this matrix can be used to obtain an intermediate variable using the interpolate_to_volume function of the SimNibs toolkit. After completing some visualization operations on this intermediate variable, it is output to the user.

[0097] In a specific embodiment, after S500, the method further includes:

[0098] S600: Calculate the effect of common transcranial electrical stimulation, specifically including:

[0099] S610. Calculate the spatial electric field distribution matrix for conventional transcranial electrical stimulation based on the lead field matrix and the feasible solution matrix. Based on the input lead field matrix (which records the contribution of each electrode to the electric field at each location in space) and the feasible solution matrix (which determines the current input and spatial layout of the electrodes), a specific calculation method (different from the envelope field calculation in time-interference stimulation) is used to derive the spatial electric field distribution matrix for conventional transcranial electrical stimulation. This matrix describes the electric field distribution in space for conventional transcranial electrical stimulation and serves as the basis for subsequent calculations of related indicators.

[0100] S620. Based on the spatial electric field distribution matrix of conventional transcranial electrical stimulation, the MRI image data with electric field value distribution, the target coordinates, and the preset stimulation range, calculate the average electric field in the restricted area of conventional transcranial electrical stimulation and the average electric field in the unrestricted area of conventional transcranial electrical stimulation.

[0101] Combining the spatial electric field distribution matrix of conventional transcranial electrical stimulation, MRI data with electric field value distribution (providing actual electric field value information), target coordinates (defining the center position of the defined area), and the preset stimulation range (determining the spatial size of the defined area), the average electric field within the defined area and the average electric field within the undefined area of conventional transcranial electrical stimulation were calculated. The calculation method is similar to that of the corresponding indicators in temporal interferometric stimulation, that is, by determining the defined area and the undefined area, accumulating the electric field values within the area and dividing it by the number of voxels within the area to obtain the average electric field value. These indicators reflect the stimulation intensity of conventional transcranial electrical stimulation in the target area and the non-target area.

[0102] The focusing of the common transcranial electrical stimulation is calculated based on the spatial electric field distribution matrix of the common transcranial electrical stimulation, the target coordinates, the preset stimulation range, and the stimulation threshold.

[0103] Based on the spatial electric field distribution matrix of conventional transcranial electrical stimulation (TES), the target coordinates, the preset stimulation range, and the stimulation threshold (a user-defined electric field activation threshold used to determine neuronal activation), the focality of TES was calculated using the formula: "Focality = number of voxels exceeding the threshold within the defined area / total number of voxels exceeding the threshold." This metric measures the degree of concentration of TES within the target area.

[0104] S700. Compare the effects of temporal interferometric stimulation and conventional transcranial electrical stimulation.

[0105] The various effect indicators of temporal interferometric stimulation calculated previously (such as the average electric field within a limited area, focusing, etc.) are compared and analyzed with the corresponding indicators of conventional transcranial electrical stimulation. The comparison can include comparison of numerical values, analysis of indicator change trends, etc., so as to intuitively understand the differences between the two stimulation methods in different aspects. The comparison method can be to take the difference, which intuitively reflects the numerical difference between the two on the same indicator; or to take the ratio, which reflects the relative multiple relationship between the two on the indicator. By comprehensively comparing these indicators, the similarities and differences in the effects of temporal interferometric stimulation and conventional transcranial electrical stimulation can be clearly presented.

[0106] In a more specific embodiment, the S610 specifically includes:

[0107] S611, reconstructing the feasible solution matrix into two current matrices;

[0108] S612. Add the two current matrices to obtain the spatial electric field distribution matrix of ordinary transcranial electrical stimulation.

[0109] Specifically, for the electric field calculation of ordinary transcranial electrical stimulation, the feasible solution matrix is reconstructed into two new matrices with the electrode index position as 2×current size and the non-index position as 0. Then these two new matrices are added together to obtain the spatial electric field distribution matrix of ordinary transcranial electrical stimulation.

[0110] In one embodiment, the S700 specifically includes: calculating the relative rate of change of the effect of time interference stimulation and the effect of ordinary transcranial electrical stimulation. It can intuitively reflect the degree to which the electric field intensity of time interference stimulation is improved in the target target area compared with ordinary transcranial electrical stimulation. For example, when the relative improvement rate is 0.2 (i.e. 20%), this means that the average electric field intensity of time interference stimulation in a limited area is 20% higher than that of ordinary transcranial electrical stimulation. Through the relative improvement rate, researchers and clinicians can more clearly understand the advantages of time interference stimulation in the target target area, thereby providing a strong basis for evaluating the stimulation effect, optimizing the stimulation plan, and selecting appropriate treatment methods.

[0111] In one embodiment, the calculating of the relative change rate of the stimulation effect of the temporal interferometric stimulation and the stimulation effect of the conventional transcranial electrical stimulation specifically includes:

[0112] Calculate the electric field enhancement at the target site during temporal interferometric stimulation (index f). This index is calculated as: (average electric field within the area defined by temporal interferometric stimulation - average electric field within the area defined by conventional transcranial electrical stimulation) / average electric field within the area defined by conventional transcranial electrical stimulation. This index reflects the magnitude of the improvement in electric field intensity at the target site during temporal interferometric stimulation compared to conventional transcranial electrical stimulation, under the same electrode placement and current conditions.

[0113] In one embodiment, the calculating of the relative change rate of the stimulation effect of the temporal interferometric stimulation and the stimulation effect of the conventional transcranial electrical stimulation further includes:

[0114] Calculate the electric field increase in non-target areas after temporal interferometric stimulation (index g). This index is calculated as: (average electric field in the non-restricted area after temporal interferometric stimulation - average electric field in the non-restricted area after conventional transcranial electrical stimulation) / average electric field in the non-restricted area after conventional transcranial electrical stimulation. This index measures the change in electric field intensity in non-target areas after temporal interferometric stimulation compared to conventional transcranial electrical stimulation, reflecting the difference in the impact of temporal interferometric stimulation on non-target areas.

[0115] In one embodiment, the calculating of the relative change rate of the stimulation effect of the temporal interferometric stimulation and the stimulation effect of the conventional transcranial electrical stimulation further includes:

[0116] Calculate the improvement in temporal interferometric stimulation focus (index h): Temporal interferometric stimulation focus improvement = (temporal interferometric stimulation focus - conventional transcranial electrical stimulation focus) / conventional transcranial electrical stimulation focus. This index can intuitively demonstrate the degree of improvement in temporal interferometric stimulation focus compared to conventional transcranial electrical stimulation. Higher focus means more targeted stimulation of the target area.

[0117] The evaluation indicators from a to h are calculated based on the nuclear magnetic resonance images with electric field value distribution. The transcranial electrical stimulation positioning simulation software has a variety of stimulation modes, the more commonly used ones are ordinary transcranial electrical stimulation and time interference stimulation. The software attached to this patent is actually divided into two modules. One is from a to e, which can input the calculation results of ordinary transcranial electrical stimulation, and the calculation results of time interference stimulation. The above calculation results refer to the intermediate calculation files and final output files of the transcranial electrical stimulation positioning simulation software; the other is from f to h, which requires the input of the calculation results of ordinary transcranial electrical stimulation and time interference stimulation at the same time, aiming to compare the electric field differences of the two stimulation methods under the same electrode placement method and current size.

[0118] Through a clear calculation formula, the differences between temporal interferometric stimulation and conventional transcranial electrical stimulation in key aspects such as target and non-target electric fields, as well as focality, are quantified. These specific numerical indicators allow researchers and clinicians to clearly and intuitively understand the differences in the effects of the two stimulation methods, providing precise data support for subsequent research and treatment decisions.

[0119] In one embodiment, the step S100 further includes: inputting a gridded three-dimensional model, specifically a gridded three-dimensional model obtained by performing brain tissue segmentation based on the subject's MRI data.

[0120] Specifically, by using software written in Python combined with the vtk package to read the gridded three-dimensional model, the total number of grids, the distribution of each grid (such as grid vertex coordinates, volume, etc.), the total number of primes, and the distribution of each voxel can be obtained. Voxel is the smallest volume unit of a three-dimensional model. A grid may contain one voxel or several voxels. In the transcranial electrical stimulation positioning simulation software, the gridding processing of the three-dimensional model will have a smaller grid density for relatively unimportant brain areas such as the cerebellum, and a larger grid density for important brain areas such as the hippocampus and thalamus.

[0121] After S700, the method further includes: S800, generating a difference rendering image based on the gridded three-dimensional model and the difference between the stimulation effect of the time interference stimulation and the stimulation effect of the ordinary transcranial electrical stimulation, as an effect evaluation result of the time interference stimulation.

[0122] See also Figure 2 , which is the visualization effect of the difference matrix obtained by subtracting the envelope spatial electric field distribution matrix of temporal interferometric stimulation from the spatial electric field distribution matrix of ordinary transcranial electrical stimulation. From left to right and from top to bottom are the electric field distribution maps of the coronal plane, sagittal plane, cross-section and three-dimensional model, respectively. The reddish area indicates that the difference between temporal interferometric stimulation and ordinary transcranial electrical stimulation is large, and the blue area indicates that the difference between temporal interferometric stimulation and ordinary transcranial electrical stimulation is small.

[0123] Of all the above outputs, the comparison between the temporal interferometric stimulation and the ordinary transcranial electrical stimulation is output in the form of pictures (ie, S800 ), and the others are output in the form of text (ie, S500 ).

[0124] In one embodiment, after S800, the method further includes:

[0125] S910 , based on the gridded three-dimensional model, calculating the data resolution, the total volume of the head model, the maximum unit volume of the head model, the minimum unit volume of the head model, the average unit volume of the head model, and the median unit volume of the head model.

[0126] Specifically, after reading the meshed 3D model, the following information can be easily obtained from the mesh information: the total head model volume, the maximum unit volume of the head model, the minimum unit volume of the head model, the average unit volume of the head model, and the median unit volume of the head model. The term "unit" can be replaced with "mesh." The calculation method described above is to sum, maximize, minimize, average, and median the 3D model's mesh distribution information. The resolution of the 3D model is the volume of the 3D model voxels, which are typically of equal size. All of the above operations can be performed using the VTK and NumPy packages.

[0127] S920 , based on the result calculated in S910 , verify the effect evaluation results of the time interference stimulation obtained in S500 and S800 .

[0128] Specifically, the model parameters calculated at S910 are used to verify the temporal interferometric stimulation effect evaluation results obtained by calculating various evaluation indicators (such as the average brain electric field and the average electric field within a defined area) at S500, as well as the difference rendering generated at S800. For example, by comparing the relationship between the electric field distribution in different regions and the unit volume of the head model, the electric field distribution is checked to see if it conforms to the structural characteristics of the model; the credibility of the details of the electric field changes is determined based on the data resolution. In this way, the accuracy and reliability of the temporal interferometric stimulation effect evaluation results are ensured.

[0129] By calculating model-related parameters and using them to verify effect evaluation results, potential errors or inconsistencies in the evaluation process can be promptly identified, prompting researchers to re-examine the calculation process and ensure that the evaluation results truly reflect the effects of temporal interferometric stimulation, providing a reliable basis for subsequent research and clinical application. This verification scheme can effectively avoid erroneous conclusions caused by model parameter issues, enhancing the scientific nature and rigor of temporal interferometric stimulation research. A unified approach to effect evaluation and verification of evaluation results will promote the standardization of temporal interferometric stimulation technology.

[0130] In one embodiment, an electronic device includes: at least one processor and at least one memory, wherein the memory stores a computer program; the computer program is loaded and executed by the processor, so that the electronic device implements the above-mentioned method for evaluating the effect of temporal interference stimulation.

[0131] In one embodiment, a storage medium stores a computer program, which, when executed by a processor, implements the above-mentioned method for evaluating the effect of temporal interference stimulation.

[0132] Based on the above, the present invention constructs a method for evaluating the effects of temporal interferometric stimulation, as well as comparative data with conventional transcranial electrical stimulation. For some functions, an operational graphical user interface (GUI) is also provided. The program code of the method is implemented in Python, and the GUI is implemented in PySide6.

[0133] The method program of the present invention can be run on Windows and MacOS. After several tests, the software results are consistent with the theoretical situation. The calculation time of this method program is about 5 minutes under the configuration of Windows system and Intel i9-10900K CPU.

[0134] The main stimulation target of the present invention is the biological brain, but in actual use, it can stimulate various entities including but not limited to other biological tissues such as the spinal cord, non-biological media such as saline, etc. The stimulation target depends on the lead field matrix input by the user and has no mandatory association with the software.

[0135] In this specification, the use of terms such as "Embodiment 1," "this embodiment," and "in one embodiment" indicates that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in the invention or at least one embodiment or example of the invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example; furthermore, the specific features, structures, materials, or characteristics described may be appropriately combined in any one or more embodiments or examples.

[0136] In the description of this specification, the terms "connect," "install," "fix," "dispose," and "have" are to be understood in a broad sense. For example, "connect" can mean a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0137] In the description of this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises", "comprising" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article or apparatus comprising the element.

[0138] The above description of the embodiments is to facilitate ordinary technicians in this technical field to understand and apply the technology of this case. People familiar with the technology in this field can obviously make various modifications to these examples easily and apply the general principles described here to other embodiments without having to go through creative work. Therefore, this case is not limited to the above embodiments. Modifications to the following situations should all be within the scope of protection of this case: ① A new technical solution implemented based on the technical solution of the present invention and combined with existing common knowledge, the technical effect produced by the new technical solution does not exceed the technical effect of the present invention; ② The equivalent replacement of some features of the technical solution of the present invention with the known technology, the technical effect produced is the same as the technical effect of the present invention; ③ The technical solution of the present invention is expandable, and the substantive content of the expanded technical solution does not exceed the technical solution of the present invention; ④ The equivalent transformation made by the content of the description and drawings of the present invention is directly or indirectly applied to other related technical fields.

Claims

1. A method for evaluating the effect of temporal interference stimulation, characterized in that: The method comprises: S100, input the lead field matrix, feasible solution matrix, target coordinates, preset stimulation range, and MRI image data with electric field value distribution; S200, calculating the envelope space electric field distribution matrix of the time interference stimulation based on the lead field matrix and the feasible solution matrix; S300, calculating the total electric field of the brain based on the envelope space electric field distribution matrix and the nuclear magnetic resonance imaging data with electric field value distribution; Based on the envelope space electric field distribution matrix, calculate the overall prime number; Based on the envelope space electric field distribution matrix, the MRI image data with electric field value distribution, the target coordinates, and the preset stimulation range, the total electric field in the limited area and the total electric field in the unrestricted area are calculated; Based on the envelope space electric field distribution matrix, the target coordinates, and the preset stimulation range, the number of voxels in the restricted area and the number of voxels in the unrestricted area are calculated; S400, calculating the average electric field of the brain, the average electric field in the limited area, and the average electric field in the unlimited area, wherein: Average electric field of the brain = total electric field of the brain / total prime number, Average electric field in the defined area = total electric field in the defined area / number of voxels in the defined area, Average electric field in the unconfined area = total electric field in the unconfined area / number of voxels in the unconfined area; S500 , based on the result calculated in S400 , obtaining an effect evaluation result of the time interference stimulation.

2. The effect evaluation method according to claim 1, characterized in that: The S200 specifically includes: S210, reconstructing the feasible solution matrix into two current matrices; S220, multiplying the two current matrices with the lead field matrix to obtain two high-frequency electric field spatial distribution matrices; S230. Apply the Grossman formula to calculate the two high-frequency electric field spatial distribution matrices to obtain the envelope spatial electric field distribution matrix of the time interference stimulation.

3. The effect evaluation method according to claim 2, characterized in that: The S400 further includes: calculating an average electric field ratio, where the average electric field ratio = average electric field in the defined area / average electric field in the brain.

4. The effect evaluation method according to claim 2 or 3, characterized in that: The S100 further includes: inputting a stimulation threshold; The S300 further includes: Based on the envelope space electric field distribution matrix and the stimulation threshold, the total number of voxels exceeding the threshold is calculated; Based on the envelope space electric field distribution matrix, the target coordinates, the preset stimulation range, and the stimulation threshold, the number of voxels exceeding the threshold in the limited area is calculated; The S400 further includes: calculating the focusing property, where the focusing property = the number of voxels exceeding the threshold in the defined area / the total number of voxels exceeding the threshold.

5. The effect evaluation method according to claim 4, characterized in that: The step S500 further includes: S600, calculating the effect of conventional transcranial electrical stimulation; S700, comparing the effects of temporal interferometric stimulation and conventional transcranial electrical stimulation; The S600 specifically includes: S610, calculating the spatial electric field distribution matrix of common transcranial electrical stimulation based on the lead field matrix and the feasible solution matrix; S620, based on the spatial electric field distribution matrix of common transcranial electrical stimulation, the nuclear magnetic resonance imaging data with electric field value distribution, the target coordinates, and the preset stimulation range, calculate the average electric field in the common transcranial electrical stimulation limited area and the average electric field in the common transcranial electrical stimulation unrestricted area, The focusing of the common transcranial electrical stimulation is calculated based on the spatial electric field distribution matrix of the common transcranial electrical stimulation, the target coordinates, the preset stimulation range, and the stimulation threshold.

6. The effect evaluation method according to claim 5, characterized in that: The S700 specifically includes: calculating the relative change rate of the effect of the time interference stimulation and the effect of the ordinary transcranial electrical stimulation.

7. The effect evaluation method according to claim 6, characterized in that: The calculation of the relative change rate of the stimulation effect of the temporal interferometric stimulation and the stimulation effect of the ordinary transcranial electrical stimulation specifically includes: Calculate the electric field increase of the target point under temporal interferometric stimulation, where the electric field increase of the target point under temporal interferometric stimulation = (the average electric field within the limited area of temporal interferometric stimulation - the average electric field within the limited area of ordinary transcranial electrical stimulation) / the average electric field within the limited area of ordinary transcranial electrical stimulation; and / or Calculate the electric field increase of the non-target target during time-interference stimulation, where the electric field increase of the non-target target during time-interference stimulation = (the average electric field in the non-limited area during time-interference stimulation - the average electric field in the non-limited area during ordinary transcranial electrical stimulation) / the average electric field in the non-limited area during ordinary transcranial electrical stimulation; and / or The improvement in temporal interferometric stimulation focusing is calculated as follows: improvement in temporal interferometric stimulation focusing = (temporal interferometric stimulation focusing - ordinary transcranial electrical stimulation focusing) / ordinary transcranial electrical stimulation focusing.

8. The effect evaluation method according to claim 7, characterized in that: The S610 specifically includes: S611, reconstructing the feasible solution matrix into two current matrices; S612. Add the two current matrices to obtain the spatial electric field distribution matrix of ordinary transcranial electrical stimulation.

9. The effect evaluation method according to claim 7 or 8, characterized in that: The S100 further includes: inputting a gridded three-dimensional model; The step S700 further includes: S800 , based on the gridded three-dimensional model and the difference between the stimulation effect of the temporal interferometric stimulation and the stimulation effect of the common transcranial electrical stimulation, a difference rendering image is generated as an effect evaluation result of the temporal interferometric stimulation.

10. The effect evaluation method according to claim 9, characterized in that: The step S800 further includes: S910, based on the gridded three-dimensional model, calculating the data resolution, the total volume of the head model, the maximum unit volume of the head model, the minimum unit volume of the head model, the average unit volume of the head model, and the median unit volume of the head model; S920 , based on the result calculated in S910 , verify the effect evaluation results of the time interference stimulation obtained in S500 and S800 .

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