A radiotherapy positioning system based on electrorheological fluid technology

Abstract

The present invention discloses a radiotherapy positioning system based on electrorheological fluid technology, which relates to the field of radiotherapy positioning technology, including an image acquisition unit that acquires a patient's CT image and determines the radiotherapy target area position information; a fixation strategy formulation unit that formulates a patient's fixation strategy, determines a key fixation area, selects a radiotherapy positioning pad, and places the radiotherapy positioning pad on the patient's to-be-fixed part; a pressure sensing unit that collects and acquires initial pressure distribution data; an electric field configuration selection unit that selects the best matching electric field configuration scheme from a preset electric field pattern library based on the radiotherapy target area position information and initial pressure distribution data; and an electric field application unit that applies an electric field to the electrorheological fluid through a microelectrode array in each chamber of the radiotherapy positioning pad, so that the radiotherapy positioning pad is formed according to the selected electric field configuration scheme. The present invention achieves high precision, dynamic adaptability, and comfort improvement in radiotherapy positioning, making the target area fixation more stable and greatly improving the patient's comfort experience.

Description

Technical Field

[0001] The invention relates to the technical field of radiotherapy positioning, and in particular to a radiotherapy positioning system based on electrorheological fluid technology. Background Art

[0002] In modern radiotherapy (abbreviated as RT), in order to ensure that the radiation acts accurately on the tumor area, patients are usually fixed in a variety of ways to avoid treatment deviations caused by changes in body position or respiratory movement. The current RT positioning methods mainly rely on physical devices such as mechanical clamps and vacuum fixation pads. Although these fixation methods have improved the stability of target positioning to a certain extent, due to the rigid characteristics of the fixation methods, it is difficult to fully adapt to the individual anatomical differences and slight changes in body position of patients, especially under the influence of dynamic activities such as breathing. Such physical devices are difficult to provide consistent and stable pressure distribution. In addition, traditional mechanical fixation systems pay little attention to the comfort of patients, and local compression may occur during the fixation process, which in turn affects the comfort and treatment experience of patients. Therefore, the rigid fixation strategy of the traditional RT positioning system has certain limitations, which not only limits the accuracy of target positioning, but also may affect the effectiveness of RT due to patient discomfort.

[0003] The application of electrorheological fluid (ER) technology provides a new idea for improving the adaptability and comfort of radiotherapy fixation systems. Electrorheological fluid can quickly change its rheological properties under an applied electric field, thereby forming a controllable semi-solid structure, which enables it to be flexibly formed according to the patient's body surface contour and positioning requirements. However, the existing radiotherapy positioning technology based on electrorheological fluid still has limitations in the accuracy of electric field configuration and pressure regulation. The existing system usually controls the formation of electrorheological fluid through a preset electric field mode. This fixation mode is difficult to adapt to the anatomical characteristics of different patients and the refined requirements of target area location. At the same time, due to the lack of real-time pressure monitoring and dynamic adjustment, the electric field is prone to uneven pressure distribution during application, resulting in local compression or relaxation areas, thereby affecting the positioning accuracy. In addition, the dynamic response capability of the existing technology is weak, and it is difficult to maintain a stable fixation effect when the body surface changes slightly due to physiological activities such as breathing, which is particularly prominent during a long period of radiotherapy. Therefore, there is still room for improvement in the existing electrorheological fluid radiotherapy positioning system in terms of pressure uniformity, dynamic adaptability and personalized accuracy. Summary of the invention

[0004] In view of the above-mentioned problems, the present invention is proposed.

[0005] Therefore, the present invention provides a radiotherapy positioning system based on electrorheological fluid technology, which can solve the problems mentioned in the background technology.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] In a first aspect, an embodiment of the present invention provides a radiotherapy positioning system based on electrorheological fluid technology, comprising: an image acquisition unit, used to acquire a CT image of a patient and determine the position information of a radiotherapy target area through image analysis; a fixation strategy formulation unit, used to formulate a fixation strategy for the patient based on the radiotherapy target area position information, determine key fixation areas, and select a radiotherapy positioning pad that matches the patient's body shape, and place the radiotherapy positioning pad at the patient's position to be fixed; a pressure sensing unit, used to collect and obtain initial pressure distribution data between the patient's body surface and the radiotherapy positioning pad; an electric field configuration selection unit, which selects the best matching electric field configuration scheme from a preset electric field pattern library based on the radiotherapy target area position information and the initial pressure distribution data; if there is no matching scheme, a new electric field configuration scheme is generated; an electric field application unit, used to apply an electric field to the electrorheological fluid through the microelectrode arrays of each chamber in the radiotherapy positioning pad, so that the radiotherapy positioning pad is formed according to the selected electric field configuration scheme.

[0008] As a preferred solution of the radiotherapy positioning system based on electrorheological fluid technology described in the present invention, the patient's CT image is obtained by performing a whole-body or local scan of the patient through a high-resolution CT scanning device to obtain a series of cross-sectional CT images, and the CT image contains the density information of the patient's body tissues and organs, which is presented in the form of grayscale values.

[0009] As a preferred solution of the radiotherapy positioning system based on electrorheological fluid technology described in the present invention, wherein: the position information of the radiotherapy target area includes three-dimensional coordinates, volume and shape characteristics; the process of determining the three-dimensional coordinates includes the following steps: determining the coordinate system of the CT image, specifically defining the head and feet direction of the patient's body as the Z axis, the left and right direction as the X axis, and the front and back direction as the Y axis; taking the uppermost slice of the patient's head as the Z axis origin, the midline of the body as the X axis origin, and the back contacting the scanning bed as the Y axis origin; marking the boundary points of the radiotherapy target area on each CT slice, and determining the geometric center coordinates and maximum range of the radiotherapy target area.

[0010] As a preferred solution of the radiotherapy positioning system based on electrorheological fluid technology described in the present invention, wherein: according to the radiotherapy target area position information, a patient fixation strategy is formulated and a key fixation area is determined, including the following steps: based on the radiotherapy target area position information, a number of concentric annular areas are divided around the patient's body surface projection position with the geometric center of the radiotherapy target area as a reference point; wherein the innermost annular area corresponds to the radiotherapy target area projection and is defined as the core fixation area; outwards are the proximal fixation area, the middle fixation area and the distal fixation area; different fixation priorities are assigned to each fixed area, which are strict, corresponding to the core fixation area, high level, corresponding to the proximal fixation area, medium, corresponding to the middle fixation area, low level, and corresponding to the distal fixation area; the range and shape of each fixed area are adjusted according to the patient's body position changes to cover all key body surface areas that affect the position of the radiotherapy target area, that is, the key fixation areas.

[0011] As a preferred solution of the radiotherapy positioning system based on electrorheological fluid technology described in the present invention, the pressure sensing unit starts the pressure sensing array embedded on the surface of the radiotherapy positioning pad at the beginning of radiotherapy, collects and analyzes the initial pressure distribution data between the patient's body surface and the radiotherapy positioning pad, and specifically includes the following steps: determining the maximum pressure point and its position, calculating the average pressure of each fixed area, identifying the pressure mutation area, and evaluating the uniformity of the pressure distribution; calculating the pressure difference between each pressure sensor and the adjacent sensor to form a gradient matrix PGM:

[0012] ;

[0013] Where i, j are the indices of the pressure sensors, is the distance between adjacent pressure sensors in the x and y directions.

[0014] Calculate the pressure gradient amplitude at each point according to the gradient matrix PGM:

[0015] ;

[0016] Defining the pressure drop threshold ,when It is marked as the pressure mutation point.

[0017] Calculate the pressure distribution uniformity index PDU:

[0018] ;

[0019] in, is the pressure value of the ith pressure sensor, is the average pressure value of all pressure sensors, is the total number of pressure sensors.

[0020] Calculate the patient's respiratory pressure fluctuation index RPI:

[0021] ;

[0022] in, and are the maximum and minimum pressures during the breathing cycle, is the average pressure, is the actual respiratory rate, is the standard respiratory rate, is the frequency adjustment factor.

[0023] The pressure distribution uniformity index PDU and the respiratory pressure fluctuation index RPI are used as initial pressure distribution data.

[0024] As a preferred solution of the radiotherapy positioning system based on electrorheological fluid technology described in the present invention, wherein: based on the radiotherapy target area position information and initial pressure distribution data, the best matching electric field configuration scheme is selected from the preset electric field pattern library; if there is no matching scheme, a new electric field configuration scheme is generated, including the following steps: integrating the geometric center coordinates of the radiotherapy target area , maximum range and initial pressure distribution data;

[0025] Access a preset electric field pattern library, which contains a variety of predefined electric field configuration schemes, each of which includes a radiotherapy target area position range, ideal pressure distribution parameters, and electric field strength and direction of each chamber in the radiotherapy positioning pad; select the best matching electric field configuration scheme from the preset electric field pattern library by calculating the electric field configuration matching index ECMI:

[0026] ;

[0027] Among them, w1, w2, w3 are weight coefficients, is the position matching degree, is the pressure matching degree, is the shape matching degree.

[0028] Among them, the position matching Calculation:

[0029] ;

[0030] in, is the geometric center coordinate of the radiotherapy target area of ​​the current plan, is the geometric center coordinate of the radiotherapy target area of ​​the electric field configuration scheme in the preset electric field pattern library, is the standard deviation in each direction, which is used to adjust the matching tolerance.

[0031] Among them, the pressure matching Calculation:

[0032] ;

[0033] in, is the pressure distribution unit of the current scheme, is the ideal pressure distribution unit value of the electric field configuration scheme in the preset electric field pattern library, is the stress index of the current solution, is the ideal pressure index value of the solution in the library, is the maximum acceptable pressure index value.

[0034] Shape matching Calculation:

[0035] ;

[0036] in, and are the minimum and maximum cross-sectional areas of the radiotherapy target area of ​​the current scheme and the radiotherapy target area of ​​the electric field configuration scheme in the preset electric field pattern library, respectively, is the shape adjustment factor.

[0037] The ECMI value of each electric field configuration scheme in the preset electric field pattern library is calculated, and the electric field configuration scheme with the highest ECMI is selected as the best matching electric field configuration scheme; if the highest ECMI value is lower than the preset threshold, it is prompted that manual intervention is required or a new electric field configuration scheme is generated.

[0038] As a preferred solution of the radiotherapy positioning system based on electrorheological fluid technology described in the present invention, if the electric field configuration matching index ECMI of each electric field configuration scheme in the preset electric field pattern library is lower than the preset threshold, a new scheme generation program is started. The generation program directly constructs the electric field configuration based on the characteristics of the electrorheological fluid and the requirements of the radiotherapy target area. The specific steps are as follows: Create an ideal electric field distribution map according to the position and shape of the radiotherapy target area ; Divide the radiotherapy positioning pad into an M×N grid, place an electrode at each grid point, and use a genetic algorithm to optimize the electrode layout; Use the charge simulation method to solve the actual electric field distribution under a given electrode layout , the electric field difference function is used to quantify the difference between the actual electric field distribution and the ideal distribution, where the objective function is:

[0039] ;

[0040] The optimization goal is to minimize D while satisfying the following constraints:

[0041] Total number of electrodes: ;

[0042] Electrode spacing limitations: ;

[0043] Voltage range limitations: ;

[0044] in, is the distance between electrodes o and p, The minimum distance allowed between electrodes, is the maximum number of electrodes allowed, are the minimum and maximum permissible values ​​of the electrode voltage; is the electrode voltage.

[0045] After the electrode layout is determined, the voltage distribution optimization phase begins. The gradient descent method is used to gradually adjust the voltage of each electrode to reduce the difference between the actual electric field and the ideal electric field.

[0046] In a second aspect, an embodiment of the present invention provides a radiotherapy positioning method based on electrorheological fluid technology, which includes: obtaining a CT image of a patient, and determining the position information of the radiotherapy target area through image analysis; formulating a patient fixation strategy based on the radiotherapy target area position information, determining the key fixation area, and selecting a radiotherapy positioning pad that matches the patient's body shape, and placing the radiotherapy positioning pad at the patient's to-be-fixed position; collecting and acquiring initial pressure distribution data between the patient's body surface and the radiotherapy positioning pad; based on the radiotherapy target area position information and the initial pressure distribution data, selecting the best matching electric field configuration scheme from a preset electric field pattern library, and generating a new electric field configuration scheme if there is no matching scheme; applying an electric field to the electrorheological fluid through the microelectrode arrays of each chamber in the radiotherapy positioning pad, so that the radiotherapy positioning pad is formed according to the selected electric field configuration scheme.

[0047] In a third aspect, an embodiment of the present invention provides a computer device, including a memory and a processor, wherein the memory stores a computer program, wherein: when the processor executes the computer program, any step of the above-mentioned radiotherapy positioning system based on electrorheological fluid technology is implemented.

[0048] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein: when the computer program is executed by a processor, any step of the above-mentioned radiotherapy positioning system based on electrorheological fluid technology is implemented.

[0049] The beneficial effect of the present invention is that the present invention realizes accurate target area positioning through CT image analysis, and formulates a fixing strategy according to the patient's body shape and target area position. The pressure sensing unit is used to collect surface pressure distribution data in real time, optimize the pressure uniformity of the positioning pad, thereby improving comfort and reducing pressure concentration. At the same time, the system dynamically applies an electric field through a microelectrode array, so that the positioning pad is adaptively shaped, and can respond to physiological changes such as breathing in real time, so as to ensure the high precision and stability of the target area during radiotherapy, and effectively improve the safety and efficacy of radiotherapy. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them:

[0051] Figure 1 Schematic diagram of the overall structure of the radiotherapy positioning system based on electrorheological fluid technology.

[0052] Figure 2 This is a computer equipment diagram of a radiotherapy positioning system based on electrorheological fluid technology. DETAILED DESCRIPTION

[0053] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0054] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0055] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0056] The present invention is described in detail with reference to schematic diagrams. When describing the embodiments of the present invention, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0057] At the same time, in the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "upper, lower, inner and outer" are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first, second or third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0058] In the present invention, unless otherwise clearly specified and limited, the terms "install, connect, connect" should be understood in a broad sense, for example: it can be a fixed connection, a detachable connection or an integral connection; it can also be a mechanical connection, an electrical connection or a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0059] Example 1

[0060] Reference Figure 1 and Figure 2 , which is the first embodiment of the present invention, provides a radiotherapy positioning system based on electrorheological fluid technology.

[0061] First, a high-resolution CT scanner is used to perform a full-body or partial scan of the patient to obtain a series of cross-sectional CT images. The CT images contain density information of the patient's tissues and organs in the form of grayscale values. Subsequently, the acquired CT images are imported into a specialized medical image processing software. The software uses an intelligent recognition algorithm to automatically segment and mark different tissue structures, including bones, soft tissues, and possible tumor areas.

[0062] The doctor adjusts and accurately defines the radiotherapy target area, and marks the surrounding important organs and sensitive tissues. Based on the doctor's markings, the three-dimensional coordinates, volume, and shape characteristics of the radiotherapy target area are calculated. The calculation rules are as follows:

[0063] First, determine the coordinate system of the CT image. Define the head and feet direction of the patient's body as the Z axis, the left and right direction as the X axis, and the front and back direction as the Y axis. The top slice of the patient's head is the origin of the Z axis, the midline of the body is the origin of the X axis, and the back touching the scanning bed is the origin of the Y axis.

[0064] Secondly, mark the boundary points of the radiotherapy target area on each CT slice. For each marked point, record its two-dimensional coordinates (X, Y) on the slice. At the same time, record the position of the slice on the Z axis to obtain the three-dimensional coordinates (X, Y, Z) of the point. Then, determine the geometric center of the radiotherapy target area. Calculate the average value of the X coordinates of all marked points to obtain , the average value of the Y coordinate is , the average value of the Z coordinate is .point That is, the geometric center coordinates of the radiotherapy target area. Next, find the maximum value Xmax and minimum value Xmin of the X coordinate, the maximum value Ymax and minimum value Ymin of the Y coordinate, and the maximum value Zmax and minimum value Zmin of the Z coordinate among all the marked points. The maximum range of the radiotherapy target area on the X axis is Xmax - Xmin, on the Y axis is Ymax -Ymin, and on the Z axis is Zmax - Zmin.

[0065] Finally, define the shape characteristics of the radiotherapy target. If the maximum ranges of the three axes are similar, the radiotherapy target is approximated as a sphere; if one axis is significantly larger than the other two, it is approximated as an ellipsoid; if the shape is irregular, record the coordinate set of key contour points and describe the shape of the radiotherapy target in the form of polygons or spline curves.

[0066] Furthermore, based on the previously obtained radiotherapy target location information, the precise location of the radiotherapy target in the patient and the surrounding anatomical structures are evaluated. The relative position relationship between the radiotherapy target and the patient's body surface is determined by considering the geometric center coordinates (Xc, Yc, Zc) of the radiotherapy target and its maximum range.

[0067] Secondly, the patient's body surface is divided into multiple areas according to the location information of the radiotherapy target area. Taking the geometric center of the radiotherapy target area as the reference point, several concentric annular areas are divided around the projection position of the body surface. The innermost annular area directly corresponds to the projection of the radiotherapy target area and is defined as the core fixed area; outwards are the proximal fixed area, the middle fixed area, and the distal fixed area.

[0068] Then, different fixation priorities are assigned to each fixation area. The core fixation area has the highest fixation priority, requiring the most stringent fixation effect; the proximal fixation area is second, and the middle fixation area is third, requiring a medium degree of fixation; the distal fixation area has the lowest priority, mainly playing an auxiliary fixation role.

[0069] Next, the patient's height, weight, and body shape (such as obesity, spinal curvature, etc.) are analyzed to estimate changes in body position during radiotherapy. Based on these factors, the range and shape of each fixed area are adjusted to ensure that all key body surface areas that may affect the location of the radiotherapy target are covered.

[0070] Finally, a detailed fixation strategy report is generated based on the above factors. The report includes the precise boundary coordinates of each fixation area, the fixation priority of each area, the recommended fixation strength, and the key points that need to be monitored during the fixation process.

[0071] Furthermore, a radiotherapy positioning pad that matches the patient's body shape is selected and placed on the patient's fixed part. A high-density pressure sensor array is pre-embedded on the surface of the radiotherapy positioning pad. The array consists of hundreds of micro pressure sensors evenly distributed on the surface of the radiotherapy positioning pad. Each sensor can independently measure local pressure with an accuracy of up to 0.1 kPa.

[0072] Next, the pressure sensor array on the surface of the radiotherapy positioning pad is activated to start collecting pressure data in real time. Each sensor samples at a frequency of 100 Hz to ensure that it can capture the slight pressure changes caused by the patient's physiological activities such as breathing. Data collection lasts for 30 seconds to obtain enough samples to analyze the dynamic characteristics of pressure distribution.

[0073] Furthermore, key features are identified, including determining the maximum pressure point and its location, calculating the average pressure of each fixation area (such as the core fixation area, the proximal fixation area, etc.), identifying the pressure mutation area, and evaluating the uniformity of the pressure distribution.

[0074] It should be noted that in order to identify the pressure mutation area, the concept of pressure gradient matrix (PGM, Pressure GradientMatrix) is introduced. For each pressure sensor, the pressure difference between it and the adjacent pressure sensor is calculated to form a gradient matrix:

[0075] ;

[0076] Where i, j are the indices of the pressure sensors, is the distance between adjacent pressure sensors in the x and y directions.

[0077] Then the pressure gradient amplitude at each point is calculated according to the gradient matrix:

[0078] ;

[0079] Defining the pressure drop threshold ,when This point is marked as a pressure mutation point.

[0080] In order to evaluate the uniformity of pressure distribution, the pressure distribution uniformity index (PDU, Pressure Distribution Uniformity) is calculated:

[0081] ;

[0082] in, is the pressure value of the ith pressure sensor, is the average pressure value of all pressure sensors, is the total number of pressure sensors. The value range of PDU is [0, 1], and the closer the value is to 1, the more uniform the pressure distribution is.

[0083] Furthermore, the patient's pressure due to physiological functions such as breathing changes over time. For this reason, the respiratory pressure fluctuation index (RPI, Respiratory Pressure Index) is introduced:

[0084] ;

[0085] in, and are the maximum and minimum pressures during the breathing cycle, is the average pressure, is the actual respiratory rate, is the standard respiratory rate (usually 12 times / minute), is the frequency adjustment factor (default is 0.5). RPI reflects the degree of influence of breathing on pressure distribution. The larger the value, the more significant the pressure fluctuation caused by breathing.

[0086] The pressure distribution uniformity index PDU and the respiratory pressure fluctuation index RPI are used as the initial pressure distribution data.

[0087] Finally, the system generates a detailed initial pressure distribution report. The report contains the following information: overall pressure distribution heat map, average pressure value of each fixed area, maximum and minimum pressure point location and value, initial pressure distribution data (pressure distribution uniformity index PDU and respiratory pressure fluctuation index RPI), and initially identified areas that may require special attention (such as points with too high or too low pressure).

[0088] Furthermore, based on the radiotherapy target area position information and the initial pressure distribution data, the best matching electric field configuration scheme is selected from the preset electric field pattern library:

[0089] First, the previously obtained geometric center coordinates (Xc, Yc, Zc) and maximum range (Dx, Dy, Dz) of the radiotherapy target and the initial pressure distribution data are integrated.

[0090] Access the library of preset electric field patterns. The library contains a variety of predefined electric field configurations, each for a specific radiation therapy target location and surface pressure distribution. Each electric field configuration contains the following information: the applicable radiation therapy target location range, the ideal pressure distribution parameters, and the electric field strength and direction of each chamber in the radiation therapy positioning pad.

[0091] In order to select the best matching electric field configuration scheme from the preset electric field pattern library, the Electric Field Configuration Matching Index (ECMI) is calculated:

[0092] ;

[0093] Among them, w1, w2, w3 are weight coefficients, satisfying w1 + w2 + w3 = 1, is the position matching degree, is the pressure matching degree, is the shape matching degree.

[0094] Among them, the position matching Calculation:

[0095] ;

[0096] in, is the geometric center coordinate of the radiotherapy target area of ​​the current plan, is the geometric center coordinate of the radiotherapy target area of ​​the electric field configuration solution in the library, is the standard deviation in each direction, which is used to adjust the matching tolerance.

[0097] Among them, the pressure matching Calculation:

[0098] ;

[0099] in, is the pressure distribution unit of the current scheme, is the ideal pressure distribution unit value of the electric field configuration scheme in the preset electric field pattern library. is the stress index of the current solution, is the ideal pressure index value of the solution in the library, is the maximum acceptable pressure index value.

[0100] Shape matching Calculation:

[0101] ;

[0102] in, and are the minimum and maximum cross-sectional areas of the radiotherapy target area of ​​the current scheme and the radiotherapy target area of ​​the electric field configuration scheme in the preset electric field pattern library, respectively. is the shape adjustment factor (default is 0.5).

[0103] Calculate the ECMI value of each power plant configuration scheme in the preset electric field pattern library, and select the scheme with the highest ECMI as the best matching electric field configuration scheme. If the highest ECMI value is lower than the preset threshold, the system will prompt that manual intervention is required or a new electric field configuration scheme is generated.

[0104] If the electric field configuration matching index ECMI of each electric field configuration scheme in the preset electric field pattern library is lower than the preset threshold, the new scheme generation program is started. The generation program directly constructs the electric field configuration based on the characteristics of the current fluid change and the requirements of the radiotherapy target area. The specific steps are as follows:

[0105] Create an ideal electric field distribution map based on the location and shape of the radiotherapy target This distribution diagram describes the ideal electric field strength and direction required at each point in space to achieve the best fixing effect.

[0106] The radiotherapy positioning pad is divided into an M×N grid, and an electrode is placed at each grid point. The genetic algorithm is used to optimize the electrode layout, and the chromosome encoding is: ,in Indicates whether an electrode is placed at this location.

[0107] Use the charge simulation method to quickly solve the actual electric field distribution under a given electrode layout The electric field difference function is then used to quantify the difference between the actual electric field distribution and the ideal distribution. The core goal of the optimization is to minimize this difference function to ensure that the generated solution is both effective and feasible. Specifically, the objective function is expressed as follows:

[0108] ;

[0109] The optimization goal is to minimize D while satisfying the following constraints:

[0110] Total number of electrodes: ;

[0111] Electrode spacing limitations: ;

[0112] Voltage range limitations: ;

[0113] in, is the distance between electrodes o and p, The minimum distance allowed between electrodes, is the maximum number of electrodes allowed, are the minimum and maximum permissible values ​​of the electrode voltage; is the electrode voltage.

[0114] After the electrode layout is determined, the voltage distribution optimization phase begins. Using the gradient descent method, the voltage of each electrode is gradually adjusted to further reduce the difference between the actual electric field and the ideal electric field:

[0115] ;

[0116] in, The voltage of the oth electrode at the tth iteration, The target function D is the electrode voltage The partial derivative of For the adaptive learning rate:

[0117] ;

[0118] in, is the number of iterations, is the attenuation constant.

[0119] It should be noted that during the entire optimization process, the fast convergence judgment criterion is continuously used to evaluate the progress of the optimization. This step is closely linked to all previous optimization steps. It determines when to stop the current optimization iteration, whether the optimization strategy needs to be adjusted, or whether a satisfactory result has been achieved. This judgment mechanism ensures the computational efficiency of the entire process and avoids unnecessary over-optimization.

[0120] Furthermore, an electric field is applied to the electrorheological fluid through the microelectrode array in each chamber, so that the radiotherapy positioning pad is formed according to the selected configuration scheme.

[0121] Furthermore, this embodiment also provides a radiotherapy positioning method based on electrorheological fluid technology, including:

[0122] S1: Obtain the patient's CT image and determine the location information of the radiotherapy target area through image analysis;

[0123] S2: According to the location information of the radiotherapy target area, formulate a patient fixation strategy, determine the key fixation area, select a radiotherapy positioning pad that matches the patient's body shape, and place the radiotherapy positioning pad at the patient's position to be fixed;

[0124] S3: Collect and obtain the initial pressure distribution data between the patient's body surface and the radiotherapy positioning pad;

[0125] S4: Based on the radiotherapy target area position information and the initial pressure distribution data, the best matching electric field configuration scheme is selected from the preset electric field pattern library. If there is no matching scheme, a new electric field configuration scheme is generated;

[0126] S5: applying an electric field to the electrorheological fluid through the microelectrode arrays in each chamber of the radiotherapy positioning pad, so that the radiotherapy positioning pad is formed according to the selected electric field configuration scheme.

[0127] like Figure 2 As shown, this embodiment also provides a computer device, which is suitable for the radiotherapy positioning system based on electrorheological fluid technology, including a memory and a processor; the memory is used to store computer executable instructions, and the processor is used to execute computer executable instructions to implement the radiotherapy positioning system based on electrorheological fluid technology proposed in the above embodiment.

[0128] The computer device may be a terminal, and the computer device includes a processor, a memory, a communication interface, a display screen and an input device connected through a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be achieved through WIFI, an operator network, NFC (near field communication) or other technologies. The display screen of the computer device may be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device may be a touch layer covered on the display screen, or a key, trackball or touchpad provided on the housing of the computer device, or an external keyboard, touchpad or mouse, etc.

[0129] This embodiment further provides a storage medium on which a computer program is stored. When the program is executed by a processor, a radiotherapy positioning system based on electrorheological fluid technology as proposed in the above embodiment is implemented.

[0130] The storage medium proposed in this embodiment and the data storage method proposed in the above embodiment belong to the same inventive concept. The technical details not fully described in this embodiment can be found in the above embodiment, and this embodiment has the same beneficial effects as the above embodiment.

[0131] In summary, the present invention has the following beneficial effects compared with the prior art: 1. The location information of the radiotherapy target area is determined by CT image analysis, and an accurate fixation strategy is formulated to form a multi-level fixation area. This design ensures the accuracy of the target area and reduces the impact of changes in the patient's body position on the target area positioning.

[0132] 2. The pressure sensing unit collects the initial pressure data between the patient's body surface and the positioning pad, and identifies pressure mutation points and uneven areas through gradient matrix and uniformity index analysis. This can optimize the patient's fixation effect, reduce pressure concentration points, thereby improving patient comfort and stabilizing target area positioning.

[0133] 3. Based on the target area location and pressure distribution data, the system selects the best electric field configuration scheme from the preset pattern library, or automatically generates a new scheme, and applies a precise electric field through the microelectrode array to achieve precise shaping of the positioning pad. This dynamic adaptive capability ensures reliable positioning in complex situations.

[0134] 4. The pressure distribution uniformity index and respiratory fluctuation index can reflect the pressure changes caused by the patient's breathing in real time. The system takes these parameters into account when applying the electric field to ensure accurate fixation of the target area during radiotherapy.

[0135] Embodiment 2 is the second embodiment of the present invention. This embodiment provides a radiotherapy positioning system based on electrorheological fluid technology. In order to verify the beneficial effects of the present invention, scientific demonstration is carried out through economic benefit calculation and simulation experiments.

[0136] The purpose of this experiment is to verify the advantages of the radiotherapy positioning system based on electrorheological fluid technology over the traditional fixation system during radiotherapy, especially in terms of fixation accuracy, comfort and pressure response. Traditional radiotherapy fixation equipment usually relies on mechanical clamps or vacuum fixation pads to ensure the stability of the target area, but these methods have significant deficiencies in pressure distribution uniformity and dynamic response capabilities. Therefore, this experiment will focus on comparing the new system with the traditional system in terms of fixation deviation, local pressure maximum and minimum values, and comfort score.

[0137] Six groups of test subjects were selected for the experiment, including different body positions and breathing states of simulated patients. To ensure the accuracy of the experiment, the experiment first used high-resolution CT scanning equipment to obtain CT images of simulated patients, and generated the three-dimensional coordinates and body surface contour information of the radiotherapy target area through image analysis software. Then, the center position, size and shape of the radiotherapy target area of ​​each test subject were determined based on the CT image, and a pressure sensor array was set near the target area to obtain the initial pressure distribution between the body surface and the positioning pad.

[0138] The experiment is divided into two main steps: the first step is to apply traditional fixation methods (including vacuum fixation pads and mechanical clamps) to record their fixation effects and pressure distribution under different body positions and breathing states; the second step is to use a radiotherapy positioning system based on electrorheological fluid technology, using electric field regulation and pressure uniformity control functions, to experiment on the same group of test subjects. The electric field configuration of the present invention is applied through a microelectrode array, and an intelligent pressure distribution adjustment module is introduced to automatically select the best electric field scheme or dynamically generate a new electric field configuration to ensure stable positioning under dynamic conditions. In addition, the system automatically adjusts the electric field under different breathing states to optimize pressure distribution and reduce surface pressure fluctuations.

[0139] To ensure comparability, the following data were recorded in both systems: target area fixation deviation, average pressure, maximum and minimum local pressure, and comfort score of each test subject. It is worth noting that due to the lack of dynamic pressure control function in the traditional fixation system, the pressure data of the traditional system during the experiment is only used as the final stable value, while the pressure data of the present invention is based on its real-time dynamic adjustment effect, reflecting its responsiveness to different respiratory states.

[0140] Table 1 Performance comparison with traditional fixed system

[0141] Test subjects Fixing method Fixed deviation (mm) Average pressure (kPa) Maximum pressure (kPa) Minimum pressure (kPa) Comfort score ( / 10) Simulated patient A (resting state) Traditional fixing system 3.6 2.2 4.0 1.4 5 Simulated patient A (resting state) The present invention 1.2 2.6 3.0 2.1 9 Simulated patient B (deep breathing state) Traditional fixing system 4.5 2.0 4.5 1.2 4 Simulated patient B (deep breathing state) The present invention 1.5 2.8 3.2 2.0 8 Simulated patient C (shallow breathing state) Traditional fixing system 3.2 2.4 3.8 1.7 6 Simulated patient C (shallow breathing state) The present invention 1.0 2.7 2.9 2.2 9 Simulated patient D (normal breathing) Traditional fixing system 3.8 2.1 4.2 1.5 5 Simulated patient D (normal breathing) The present invention 1.4 2.9 3.1 2.0 8 Simulated Patient E (Heavy Breathing) Traditional fixing system 5.0 1.9 4.8 1.3 3 Simulated Patient E (Heavy Breathing) The present invention 1.8 3.0 3.3 2.1 7 Simulated patient F (no breathing) Traditional fixing system 3.0 2.3 3.6 1.8 6 Simulated patient F (no breathing) The present invention 0.9 2.8 2.9 2.2 9

[0142] As shown in Table 1, the present invention shows obvious advantages in multiple indicators. First, in terms of fixation deviation, the average fixation deviation of the present invention is significantly lower than that of the traditional system. In a resting state, the fixation deviation of the traditional system is about 3.0mm to 3.6mm, while that of the present invention is only 0.9mm to 1.5mm. This result shows that the electric field adjustment function of the new system can perform more precise pressure control according to the patient's body surface characteristics, thereby improving the accuracy of target positioning. The improvement in fixation accuracy is particularly suitable for radiotherapy applications with high requirements for precise positioning, which helps to reduce target position deviation and improve treatment effects.

[0143] In terms of pressure distribution, the average pressure of the present invention is controlled between 2.6 and 3.0 kPa, while the pressure fluctuation range of the traditional system is wider, and the local pressure peak often reaches 4.5 kPa or even higher, indicating that the pressure concentration phenomenon in the local area of ​​the traditional system is more serious. This uneven pressure distribution can easily cause local discomfort to the patient and may even cause certain compression damage to the skin. In contrast, when the present invention dynamically adjusts the pressure, the local pressure peak is controlled below 3.3 kPa, showing its more uniform pressure distribution effect, which helps to relieve local compression and improve the comfort of the patient.

[0144] For the comfort score, the average score of the present invention among all experimental subjects was 8 to 9, while the traditional system was only 3 to 6. This result shows that the present invention significantly improves the overall comfort of patients by dynamically adjusting the electric field in real time. Especially in the dynamic environment of deep breathing or heavy breathing, the comfort score of the electrorheological fluid system shows obvious advantages. The traditional system shows poor comfort under these conditions because it lacks the function of dynamically adjusting pressure and cannot adapt to the slight changes in the patient's body shape during breathing. The present invention can respond to the body deformation caused by breathing, and ensure the stability of pressure distribution through electric field regulation, thereby improving the comfort in a dynamic environment.

[0145] In summary, it can be seen from the experimental data that the present invention exhibits excellent performance in multiple key indicators. Compared with traditional mechanical clamps and vacuum fixation pads, the present invention not only improves the fixation accuracy of the radiotherapy target area, but also significantly improves the patient's comfort through uniform pressure distribution and dynamic adjustment capabilities. This advantage comes from the rheological characteristics of the electrorheological fluid, which enables the present invention to adjust the pressure in real time under the control of an external electric field, adapting to the changes in the patient's different body surface shapes and respiratory states, thereby solving the shortcomings of traditional fixation systems in dynamic adaptability, comfort and uniformity of pressure distribution. The present invention provides a new technical path for radiotherapy positioning, greatly enhancing the patient's comfort experience and treatment accuracy during radiotherapy.

[0146] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A radiotherapy positioning system based on electrorheological fluid technology, characterized in that: include, An image acquisition unit is used to obtain CT images of the patient and determine the location information of the radiotherapy target area through image analysis; A fixation strategy formulation unit, used to formulate a fixation strategy for the patient according to the radiotherapy target area position information, determine the key fixation area, and select a radiotherapy positioning pad that matches the patient's body shape, and place the radiotherapy positioning pad at the patient's position to be fixed; A pressure sensing unit, used to collect and obtain initial pressure distribution data between the patient's body surface and the radiotherapy positioning pad; An electric field configuration selection unit, which selects the best matching electric field configuration scheme from a preset electric field pattern library based on the radiotherapy target area position information and initial pressure distribution data; if there is no matching scheme, generates a new electric field configuration scheme; An electric field applying unit, used for applying an electric field to the electrorheological fluid through the microelectrode arrays in each chamber of the radiotherapy positioning pad, so that the radiotherapy positioning pad is formed according to the selected electric field configuration scheme; The pressure sensing unit starts the pressure sensing array embedded in the surface of the radiotherapy positioning pad at the beginning of radiotherapy, collects and analyzes the initial pressure distribution data between the patient's body surface and the radiotherapy positioning pad, and specifically includes the following steps: Determine the maximum pressure point and its location, calculate the average pressure in each fixed area, identify areas of sudden pressure changes, and evaluate the uniformity of pressure distribution; Calculate the pressure difference between each pressure sensor and the adjacent sensor to form a gradient matrix PGM: ； Where i, j are the indices of the pressure sensors, is the distance between adjacent pressure sensors in the x and y directions; Calculate the pressure gradient amplitude at each point according to the gradient matrix PGM: ； Defining the pressure drop threshold ,when When , it is marked as the pressure mutation point; Calculate the pressure distribution uniformity index PDU: ； in, is the pressure value of the ith pressure sensor, is the average pressure value of all pressure sensors, is the total number of pressure sensors; Calculate the patient's respiratory pressure fluctuation index RPI: ； in, and are the maximum and minimum pressures during the breathing cycle, is the average pressure, is the actual respiratory rate, is the standard respiratory rate, is the frequency adjustment factor; Using the pressure distribution uniformity index PDU and the respiratory pressure fluctuation index RPI as initial pressure distribution data; Based on the radiotherapy target area position information and the initial pressure distribution data, the best matching electric field configuration scheme is selected from the preset electric field pattern library; if there is no matching scheme, a new electric field configuration scheme is generated, including the following steps: Integrated geometric center coordinates of radiotherapy target area , maximum range and initial pressure distribution data; Accessing a preset electric field pattern library, wherein the preset electric field pattern library contains a plurality of predefined electric field configuration schemes, each electric field configuration scheme including a radiotherapy target area position range, an ideal pressure distribution parameter, and an electric field strength and direction of each chamber in the radiotherapy positioning pad; By calculating the electric field configuration matching index ECMI, the best matching electric field configuration scheme is selected from the preset electric field pattern library: ； Among them, w1, w2, w3 are weight coefficients, is the position matching degree, is the pressure matching degree, is the shape matching degree; Among them, the position matching Calculation: ； in, is the geometric center coordinate of the radiotherapy target area of ​​the current plan, is the geometric center coordinate of the radiotherapy target area of ​​the electric field configuration scheme in the preset electric field pattern library, is the standard deviation in each direction, which is used to adjust the matching tolerance; Among them, the pressure matching Calculation: ； in, is the pressure distribution unit of the current scheme, is the ideal pressure distribution unit value of the electric field configuration scheme in the preset electric field pattern library, is the stress index of the current solution, is the ideal pressure index value of the solution in the library, is the maximum acceptable pressure index value; Shape matching Calculation: ； in, and are the minimum and maximum cross-sectional areas of the radiotherapy target area of ​​the current scheme and the radiotherapy target area of ​​the electric field configuration scheme in the preset electric field pattern library, respectively, is the shape adjustment factor; Calculate the ECMI value of each electric field configuration scheme in the preset electric field pattern library, and select the electric field configuration scheme with the highest ECMI as the best matching electric field configuration scheme; if the highest ECMI value is lower than the preset threshold, it is prompted that manual intervention is required or a new electric field configuration scheme is generated; If the electric field configuration matching index ECMI of each electric field configuration scheme in the preset electric field pattern library is lower than the preset threshold, a new scheme generation program is started. The generation program directly constructs the electric field configuration based on the characteristics of the current fluid change and the requirements of the radiotherapy target area. The specific steps are as follows: Create an ideal electric field distribution map based on the location and shape of the radiotherapy target ; The radiotherapy positioning pad is divided into an M×N grid, an electrode is placed at each grid point, and the electrode layout is optimized using a genetic algorithm; Use charge simulation to solve the actual electric field distribution under a given electrode layout , the electric field difference function is used to quantify the difference between the actual electric field distribution and the ideal distribution, where the objective function is: ； The optimization goal is to minimize D while satisfying the following constraints: Total number of electrodes: ; Electrode spacing limitations: ; Voltage range limitations: ; in, is the distance between electrodes o and p, The minimum distance allowed between electrodes, is the maximum number of electrodes allowed, are the minimum and maximum permissible values ​​of the electrode voltage; is the electrode voltage; After the electrode layout is determined, the voltage distribution optimization phase begins. The gradient descent method is used to gradually adjust the voltage of each electrode to reduce the difference between the actual electric field and the ideal electric field.

2. The radiotherapy positioning system based on electrorheological fluid technology as claimed in claim 1, characterized in that: The CT image of the patient is obtained by performing a whole-body or local scan of the patient using a high-resolution CT scanning device to obtain a series of cross-sectional CT images. The CT image contains density information of tissues and organs in the patient's body and is presented in the form of grayscale values.

3. The radiotherapy positioning system based on electrorheological fluid technology as claimed in claim 2, characterized in that: The radiotherapy target area position information includes three-dimensional coordinates, volume and shape characteristics; the process of determining the three-dimensional coordinates includes the following steps: Determine the coordinate system of the CT image, specifically define the head and feet direction of the patient's body as the Z axis, the left and right direction as the X axis, and the front and back direction as the Y axis; take the top slice of the patient's head as the origin of the Z axis, the midline of the body as the origin of the X axis, and the back contacting the scanning bed as the origin of the Y axis; Mark the boundary points of the radiotherapy target area on each CT slice, and determine the geometric center coordinates and maximum range of the radiotherapy target area.

4. The radiotherapy positioning system based on electrorheological fluid technology as claimed in claim 3, characterized in that: According to the radiotherapy target area location information, a patient fixation strategy is formulated to determine the key fixation area, including the following steps: Based on the radiotherapy target area position information, a number of concentric annular areas are divided around the patient's body surface projection position with the geometric center of the radiotherapy target area as a reference point; wherein the innermost annular area corresponds to the radiotherapy target area projection and is defined as the core fixed area; outwards are the proximal fixed area, the middle fixed area and the distal fixed area; Different fixing priorities are assigned to each fixing area, which are strict, corresponding to the core fixing area, high level, corresponding to the proximal fixing area, medium level, corresponding to the mid-end fixing area, and low level, corresponding to the distal fixing area; The range and shape of each fixed area are adjusted according to the patient's body position changes to cover all key body surface areas that affect the location of the radiotherapy target, namely the key fixed areas.

5. A radiotherapy positioning method based on electrorheological fluid technology, based on the radiotherapy positioning system based on electrorheological fluid technology according to any one of claims 1 to 4, characterized in that: include, Obtain the patient's CT image and determine the location information of the radiotherapy target area through image analysis; According to the radiotherapy target area position information, a patient fixation strategy is formulated, key fixation areas are determined, and a radiotherapy positioning pad adapted to the patient's body shape is selected, and the radiotherapy positioning pad is placed at the patient's position to be fixed; Collecting and obtaining initial pressure distribution data between the patient's body surface and the radiotherapy positioning pad; Based on the radiotherapy target area position information and the initial pressure distribution data, the best matching electric field configuration scheme is selected from the preset electric field pattern library, and if there is no matching scheme, a new electric field configuration scheme is generated; An electric field is applied to the electrorheological fluid through the microelectrode arrays in each chamber of the radiotherapy positioning pad, so that the radiotherapy positioning pad is formed according to the selected electric field configuration scheme.

6. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the radiotherapy positioning system based on electrorheological fluid technology described in any one of claims 1 to 4 are implemented.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the radiotherapy positioning system based on electrorheological fluid technology described in any one of claims 1 to 4 are implemented.

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