Head spatial positioning method, device and system based on electrical impedance imaging

Abstract

The present invention discloses a method, device, and system for spatial head positioning based on electrical impedance imaging. The method includes: constructing a corresponding three-dimensional model based on the basic parameters of a flexible electrode cap and performing finite element meshing to obtain a three-dimensional mesh model; calculating the electric field distribution of the sampling points of the three-dimensional mesh model according to preset calculation rules to obtain corresponding touch electrode response information; generating a sensitive field matrix corresponding to the sampling points and electrode pairs in the flexible electrode cap based on the touch electrode response information; performing projection matching on the sensitive field matrix based on the initial voltage data of the electrode pairs to obtain projection matching information; performing model training based on the projection matching information and the tensile deformation data of the flexible electrode cap to obtain a voltage feature-space coordinate mapping relationship and parsing the induced voltage data of the electrode pairs to obtain corresponding target coordinate information. The above method obtains the voltage change of the flexible electrode cap and parses the coordinate information to improve the accuracy and stability of positioning.

Description

Technical Field

[0001] The present invention relates to the field of neuronavigation technology, and in particular to a head spatial positioning method, device and system based on electrical impedance imaging. By using flexible conductive materials and a stylus pen to work together, high-precision dynamic spatial coordinate tracking applied to the head is achieved, and the system is suitable for fields such as neurosurgery navigation, neuromodulation and medical rehabilitation. Background Art

[0002] Traditional neurosurgical navigation techniques (such as optical navigation and electromagnetic navigation) rely on rigid markers or external sensors. For example, these require fixing optical markers or electromagnetic sensors to the individual's head, which imposes numerous limitations, increases surgical time, and complicates the procedure. Furthermore, tissue displacement during surgery can easily cause positioning drift of the optical markers or electromagnetic sensors. Furthermore, reliance on precision optical components or customized equipment leads to high maintenance costs. The clinical application of existing noninvasive neuromodulation technologies (such as transcranial electrical stimulation, transcranial magnetic stimulation, transcranial ultrasound stimulation, and transcranial light stimulation) also urgently requires easy-to-use and accurate head spatial positioning methods and systems.

[0003] Existing electrical impedance tomography (EIT) positioning methods rely on indirect inference of target position through image reconstruction, resulting in significant time-consuming calculations. Furthermore, EIT systems typically use fixed electrode arrays, which cannot adapt to head deformation or electrode cap stretching, resulting in poor positioning accuracy. Consequently, existing technologies for head positioning suffer from poor positioning accuracy and high application costs. Summary of the Invention

[0004] The embodiments of the present invention provide a method, device and system for spatial positioning of the head based on electrical impedance imaging, aiming to solve the problems of poor positioning accuracy and high application cost in existing methods used for head positioning in clinical or scientific research applications.

[0005] In a first aspect, an embodiment of the present invention provides a head spatial positioning method based on electrical impedance tomography, which is applied to a positioning and analysis terminal, wherein a data acquisition unit in the positioning and analysis terminal is respectively connected to a stylus and a flexible electrode cap to realize data information transmission, and the flexible electrode cap covers the outer surface of a three-dimensional head model, wherein the method includes:

[0006] Constructing a corresponding three-dimensional model based on the image segmentation information of the individual user and the basic parameters of the flexible electrode cap;

[0007] Performing finite element meshing on the three-dimensional model to obtain a three-dimensional mesh model;

[0008] Calculating the electric field distribution of the sampling points in the three-dimensional grid model according to preset calculation rules to obtain corresponding touch electrode response information;

[0009] generating a sensitive field matrix corresponding to the sampling points and the electrode pairs in the flexible electrode cap according to the touch electrode response information;

[0010] Performing projection matching on the initial voltage data of the electrode pairs and the sensitive field matrix to obtain projection matching information; the initial voltage data is voltage data of the electrode pairs at various positions of the flexible electrode cap when the stylus touches the electrode pairs;

[0011] Performing model training based on the projection matching information and the tensile deformation data of the flexible electrode cap to obtain a regression model based on the voltage feature-space coordinate mapping relationship;

[0012] The induced voltage data of the electrode pair is analyzed according to the regression model to obtain corresponding target coordinate information; the induced voltage data is voltage data of the electrode pair when the stylus touches a certain position in the flexible electrode cap.

[0013] In a second aspect, an embodiment of the present invention further provides a head spatial positioning device based on electrical impedance imaging, wherein the device is configured in a positioning and analysis terminal, and a data acquisition unit in the positioning and analysis terminal is respectively connected to a stylus and a flexible electrode cap to realize data information transmission, and the flexible electrode cap covers the outer surface of the three-dimensional head model. The device is used to perform the head spatial positioning method based on electrical impedance imaging as described in the first aspect above, and the device includes:

[0014] A three-dimensional model construction module, configured to construct a corresponding three-dimensional model based on the image segmentation information of the individual user and the basic parameters of the flexible electrode cap;

[0015] A three-dimensional mesh model acquisition module is used to perform finite element meshing on the three-dimensional model to obtain a three-dimensional mesh model;

[0016] an electric field distribution calculation module, configured to calculate the electric field distribution of the sampling points in the three-dimensional grid model according to preset calculation rules to obtain corresponding touch electrode response information;

[0017] A sensitive field matrix acquisition module, configured to generate a sensitive field matrix corresponding to the sampling points and the electrode pairs in the flexible electrode cap according to the touch electrode response information;

[0018] a projection matching information acquisition module, configured to perform projection matching on the sensitive field matrix according to the initial voltage data of the electrode pairs to obtain projection matching information; the initial voltage data being the voltage data of the electrode pairs at various positions in the flexible electrode cap touched by the stylus;

[0019] A regression model building module, configured to perform model training based on the projection matching information and the tensile deformation data of the flexible electrode cap to obtain a regression model based on a voltage feature-space coordinate mapping relationship;

[0020] The target coordinate information acquisition module is used to analyze the induced voltage data of the electrode pair according to the regression model to obtain corresponding target coordinate information; the induced voltage data is the voltage data of the electrode pair when the stylus touches a certain position in the flexible electrode cap.

[0021] In a third aspect, an embodiment of the present invention further provides a head space positioning system based on electrical impedance imaging, wherein the system includes a positioning analysis terminal, a stylus pen, and a flexible electrode cap;

[0022] The stylus is provided with an excitation unit, and the edge of the flexible electrode cap is provided with a ring electrode array consisting of a plurality of electrode pairs;

[0023] The positioning and analysis terminal is equipped with a communication unit, an interaction unit, a power supply unit, a control unit, a data acquisition unit, a sensitive field modeling unit, a stylus position reconstruction unit and a visualization unit;

[0024] The communication unit, the interaction unit, the power supply unit, the sensitive field modeling unit, and the stylus position reconstruction unit are all in communication connection with the control unit, and the control unit is also in communication connection with the excitation unit;

[0025] The stylus position reconstruction unit is in communication with the sensitive field modeling unit and the visualization unit; the data acquisition unit is in communication with the sensitive field modeling unit, the annular electrode array and the excitation unit respectively;

[0026] The positioning and analysis terminal is internally configured with a memory. When the positioning and analysis terminal executes the program stored in its internal memory, the steps of the head spatial positioning method based on electrical impedance imaging described in the first aspect are implemented.

[0027] In a fourth aspect, an embodiment of the present invention further provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the steps of the head spatial positioning method based on electrical impedance imaging as described in the first aspect above are implemented.

[0028] The embodiment of the present invention provides a method, device and system for head spatial positioning based on electrical impedance imaging, the method comprising: constructing a corresponding three-dimensional model based on basic parameters of the flexible electrode cap and the image segmentation information of the individual user; performing finite element meshing on the three-dimensional model to obtain a three-dimensional mesh model; performing electric field distribution calculation on the sampling points in the three-dimensional mesh model according to preset calculation rules to obtain corresponding touch electrode response information; generating a sensitive field matrix corresponding to the sampling points and the electrode pairs in the flexible electrode cap according to the touch electrode response information; performing projection matching on the sensitive field matrix based on the initial voltage data of the electrode pairs to obtain projection matching information; performing model training based on the projection matching information and the tensile deformation data of the flexible electrode cap to obtain a voltage feature-space coordinate mapping relationship and parsing the induced voltage data of the electrode pairs to obtain corresponding target coordinate information. The above method monitors voltage changes in real time through the flexible electrode cap and parses to obtain coordinate information, thereby improving the accuracy and stability of the positioning process. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0030] Figure 1 A flowchart of a method for head spatial positioning based on electrical impedance imaging provided by an embodiment of the present invention;

[0031] Figure 2 A schematic diagram of an application scenario of the head spatial positioning method based on electrical impedance imaging provided by an embodiment of the present invention;

[0032] Figure 3 This is an application effect diagram of the head spatial positioning method based on electrical impedance imaging provided by an embodiment of the present invention;

[0033] Figure 4 A structural diagram of a flexible electrode cap according to an embodiment of the present invention;

[0034] Figure 5 A schematic block diagram of a head space positioning device based on electrical impedance imaging provided by an embodiment of the present invention;

[0035] Figure 6 This is a schematic block diagram of a head spatial positioning system based on electrical impedance imaging provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0036] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0037] It will be understood that when used in this specification and the appended claims, the terms “comprises” and “comprising” indicate the presence of described features, integers, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0038] It should also be understood that the terms used in the present specification are only for the purpose of describing particular embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0039] It should be further understood that the term "and / or" used in the present description and appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0040] See also Figure 1 and Figure 2 As shown in the figure, the embodiment of the present invention provides a head space positioning method based on electrical impedance imaging, which is applied to the positioning and analysis terminal 20 and is executed by the application software installed in the positioning and analysis terminal 20; the data acquisition unit 5 in the positioning and analysis terminal 20 is respectively connected to the touch pen 8 and the flexible electrode cap 6 to realize the transmission of data information. The specific application process is as follows Figure 3 As shown, the flexible electrode cap 6 covers the outer surface of the three-dimensional head model 30. When the stylus pen 8 touches a certain position of the flexible electrode cap 6, the electrode pair set at the edge of the flexible electrode cap 6 can sense the voltage signal accordingly. The data acquisition unit can collect the voltage signal generated by the electrode pair, thereby converting the analog quantity into a digital quantity and obtaining the corresponding voltage data. The positioning analysis terminal 20 further analyzes the voltage data to obtain the accurate touch position of the stylus pen 8 on the flexible electrode cap 6, that is, to obtain the target coordinate information. Figure 1 As shown, the method includes steps S110 to S170.

[0041] S110 , constructing a corresponding three-dimensional model according to the image segmentation information of the individual user and the basic parameters of the flexible electrode cap.

[0042] The image segmentation information of the individual user is combined with the basic parameters of the flexible electrode cap to construct a corresponding three-dimensional model, where the three-dimensional model is a virtual three-dimensional model. Specifically, based on the image segmentation information, the virtual model of the flexible electrode cap is placed on a high-precision three-dimensional head model corresponding to the image segmentation information, and based on the basic parameters of the flexible electrode cap, the virtual model of the flexible electrode cap is fused with the three-dimensional head model corresponding to the image segmentation information, so as to construct a composite model including tissue conductivity (σ) and relative dielectric constant distribution as the corresponding three-dimensional model. Among them, the basic parameters of the flexible electrode cap include electrode cap size, electrode spacing, electrode diameter, material conductivity, etc.; the parameter values in the basic parameters can be obtained through actual measurement or experimental measurement. For example, the conductivity of the conductive material in the electrode cap can be calibrated through experimental measurement (for example, if the conductive material is Ag / AgCl coating, its conductivity can be calibrated to σ by measurement). In this 3D model, the stylus model can be simplified as a point current source. The virtual position of the stylus model can be dynamically bound to the coordinate system of the 3D model to set the node parameters of the 3D head model and each virtual component in the 3D model. The virtual components include the stylus model and the flexible electrode cap model.

[0043] In a specific embodiment, before step S110, the following steps are further included: receiving brain image data of an individual user, performing segmentation processing on the brain image data according to a preset segmentation model to obtain corresponding initial segmentation information; performing segmentation optimization processing on the initial segmentation information according to a preset segmentation optimization model to obtain corresponding image segmentation information; and using the image segmentation information as basic data for constructing the three-dimensional head model.

[0044] Individual user brain image data, such as MRI / CT images, can be imported into the positioning and analysis terminal. Segmentation is then performed based on a pre-set segmentation model. Specifically, an anisotropic diffusion filter is used to remove image noise while preserving tissue edge features. Brain tissue is then segmented from the de-noised images using a segmentation model integrated with a deep learning framework (such as U-Net or nnU-Net). Based on the pre-trained segmentation model, the scalp, skull, cerebrospinal fluid, gray matter, and white matter are automatically segmented to obtain initial segmentation information.

[0045] The initial segmentation information is then optimized using a pre-set segmentation optimization model, such as by combining the cross-entropy loss function with the Dice coefficient, to optimize segmentation accuracy and obtain more accurate image segmentation information. This image segmentation information serves as the basis for constructing a 3D head model, which simulates the 3D physical structure of an individual user's head.

[0046] S120 , performing finite element meshing on the three-dimensional model to obtain a three-dimensional mesh model.

[0047] Finite element meshing is performed on the three-dimensional model obtained in the above steps to further obtain a three-dimensional mesh model. Finite element meshing is to divide the three-dimensional model into specific meshes to obtain a three-dimensional mesh model containing mesh information.

[0048] In a specific embodiment, step S120 includes the following steps: meshing the sensing area of the three-dimensional model according to a preset finite element model to obtain corresponding mesh division information; determining the three-dimensional coordinate position of each grid according to the position parameters of each grid in the mesh division information; and adding the mesh division information and the three-dimensional coordinate position to the three-dimensional model to obtain a corresponding three-dimensional mesh model.

[0049] Specifically, the sensing area of the three-dimensional model can be meshed according to a preset finite element model. The finite element model includes an unstructured tetrahedral mesh and a mesh size parameter. For example, the mesh size of the size parameter can be set to 0.1 mm. Then, the unstructured tetrahedral mesh can be used in combination with the size parameter to mesh the sensing area of the three-dimensional model to obtain mesh division information, thereby ensuring the accuracy of the electric field calculation. Furthermore, the three-dimensional coordinate position of each grid can be determined according to the position parameters of each grid in the mesh division information. Specifically, the center point coordinates of the grid can be calculated according to the position parameters of the grid. A vertical line perpendicular to the plane where the grid is located is drawn with the center point coordinates as the origin. The intersection coordinates of the vertical line and the virtual model of the flexible electrode cap in the three-dimensional model are the three-dimensional coordinate position of the grid. The obtained mesh division information and three-dimensional coordinate position are added to the three-dimensional model to obtain a three-dimensional mesh model.

[0050] S130 , performing electric field distribution calculation on the sampling points in the three-dimensional grid model according to a preset calculation rule to obtain corresponding touch electrode response information.

[0051] After meshing, the electric field distribution of the sampling points in the 3D mesh model can be calculated according to preset calculation rules to obtain the corresponding touch electrode response information. The sampling points in the 3D mesh model correspond to the touch locations of the stylus. For example, if the sensing area in the 3D mesh model is divided into a 100×100 grid, there will be 10,000 touch locations, each corresponding to a sampling point. The electric field distribution is calculated for each sampling point to obtain the corresponding voltage response value. The voltage response values of all sampling points constitute the touch electrode response information of the 3D mesh model.

[0052] In a specific embodiment, step S130 includes the following steps: performing spatial potential calculation on the three-dimensional grid model according to the calculation rules and the basic parameters to obtain corresponding spatial potential distribution information; obtaining the voltage response value of the electrode pair adjacent to the sampling point when each sampling point contacts the stylus according to the spatial potential distribution information to obtain the touch electrode response information.

[0053] Specifically, the spatial potential can be calculated for each sampling point based on the calculation rules and the basic parameters of the flexible electrode cap. The calculation rules are configured with finite element equations, which are solved based on the material conductivity and the preset voltage value to obtain the spatial potential distribution information induced by the stylus at different sampling points in the three-dimensional grid model when the stylus is stimulated by the preset voltage value. Based on the spatial potential distribution information, the voltage response value V of the electrode pair adjacent to the sampling point in the electrode array is further calculated when the stylus acts as a point current source (position (X, Y, Z)) and contacts the sampling point. ij (X, Y, Z), thereby obtaining the touch electrode response information.

[0054] S140: Generate a sensitive field matrix corresponding to the sampling points and the electrode pairs in the flexible electrode cap according to the touch electrode response information.

[0055] The sensitive field matrix corresponding to the sampling points and the electrode pairs in the flexible electrode cap is generated based on the obtained touch electrode response information. Specifically, each sampling point in the three-dimensional grid model can be traversed, and the corresponding sparse sensitive field matrix S is generated based on the correspondence between the sampling points and the electrode pairs and the touch electrode response information, where S∈R M×N (M is the number of electrode pairs, and N is the number of spatial sampling points.) Generating the sensitive field matrix S requires processing the matrix to obtain a data structure consistent with the actual position, and compressing and storing the sensitive field matrix S through singular value decomposition (SVD) to reduce the complexity of real-time calculations.

[0056] S150 , performing projection matching on the initial voltage data of the electrode pair and the sensitive field matrix to obtain projection matching information.

[0057] Projection matching information is obtained by performing projection matching on the initial voltage data of the pair and the sensitive field matrix, wherein the initial voltage data is voltage data of the electrode pairs at various positions of the flexible electrode cap touched by the stylus.

[0058] The initial voltage data includes voltage data corresponding to each position, and a group of voltage data corresponds to one position. Feature extraction can be performed on the initial voltage data, and vector features can be extracted from each group of voltage data. The vector features are then projected and matched with the sensitive field matrix S to obtain projection matching information corresponding to each position.

[0059] S160 , performing model training according to the projection matching information and the tensile deformation data of the flexible electrode cap to obtain a regression model based on a voltage feature-space coordinate mapping relationship.

[0060] Model training can be performed based on the projection matching information and the tensile deformation data of the flexible electrode cap to obtain a regression model based on the voltage feature-space coordinate mapping relationship. Specifically, a lightweight machine learning method can be used for model training to establish a regression model based on the voltage feature-space coordinate mapping relationship; tensile deformation data is added during the model training process, and robustness can be enhanced by adding tensile deformation data during the model training process. The tensile deformation data is also the simulation data of the tensile deformation of the electrode cap, and the simulation data of the tensile deformation of the electrode cap is obtained by generating voltage-position pairs in a deformation scenario through finite element simulation.

[0061] S170 , analyzing the induced voltage data of the electrode pair according to the regression model to obtain corresponding target coordinate information.

[0062] During the actual application of spatial positioning, the electrode pairs at the edge of the electrode cap can be monitored in real time to obtain induced voltage data. The induced voltage data of the electrode pairs can be analyzed based on the regression model constructed in the above steps to obtain the corresponding target coordinate information. The induced voltage data is the voltage data generated when the stylus touches the electrode pair at a certain position in the flexible electrode cap.

[0063] In a specific embodiment, step S170 includes the following steps: extracting corresponding voltage vector features from the induced voltage data; mapping the voltage vector features according to the voltage feature-space coordinate mapping relationship in the regression model to parse and obtain the corresponding initial coordinate position as the corresponding target coordinate information.

[0064] Specifically, the voltage vector feature can be extracted from the induced voltage data, that is, the voltage vector V of the induced voltage data collected in real time. real The principal component extraction is performed to obtain the voltage vector feature. The voltage vector feature is mapped according to the obtained voltage feature-space coordinate mapping relationship, thereby realizing the coordinate position analysis of the voltage vector feature and obtaining the initial coordinate position, which can be used as the target coordinate information.

[0065] In a specific embodiment, after mapping the voltage vector feature according to the voltage feature-space coordinate mapping relationship in the regression model to resolve and obtain the corresponding initial coordinate position, it also includes: performing position compensation on the initial coordinate position according to a preset position compensation strategy and the induced voltage data to obtain the corresponding compensated coordinate position as the target coordinate information.

[0066] To further improve the accuracy of coordinate acquisition, after obtaining the initial coordinate, position compensation can be performed on the initial coordinate. The deformation of the flexible electrode cap is estimated using the induced voltage data, thereby compensating the initial coordinate and obtaining a more accurate compensated coordinate to use as the target coordinate.

[0067] In a specific embodiment, the position compensation is performed on the initial coordinate position according to a preset position compensation strategy and the induced voltage data to obtain a corresponding compensated coordinate position as the target coordinate information, including: obtaining voltage gradient change information of the edge position in the induced voltage data; performing compensation calculation on the voltage gradient change information according to the position compensation strategy to obtain a corresponding position compensation value; and performing position compensation on the initial coordinate position according to the position compensation value to obtain a corresponding compensated coordinate position.

[0068] Specifically, the voltage gradient change information of the edge position in the induced voltage data can be obtained. The voltage gradient change information is also the voltage gradient change information of the electrode pair at the edge of the electrode cap monitored in real time. The obtained voltage gradient change information is compensated and calculated through the position compensation strategy. The compensation strategy can be a Kalman filter operation, which performs compensation calculation on the voltage gradient change information through Kalman filtering to obtain an estimated deformation variable ΔX as the corresponding position compensation value. The initial coordinate position can be compensated by the position compensation value. Specifically, the estimated deformation variable can be fed back to the above-mentioned regression model, and the estimated deformation variable and the initial coordinate position are comprehensively analyzed based on the regression model to achieve position compensation. The final output compensation coordinate position is: X final = X pred + ΔX, X pred is the initial coordinate position, X final To compensate the coordinate position.

[0069] In the head spatial positioning method based on electrical impedance imaging disclosed in the above embodiment, the method includes: constructing a corresponding three-dimensional model based on the basic parameters of the flexible electrode cap; performing finite element meshing on the three-dimensional model to obtain a three-dimensional mesh model; calculating the electric field distribution of the sampling points in the three-dimensional mesh model according to preset calculation rules to obtain corresponding touch electrode response information; generating a sensitive field matrix corresponding to the sampling points and the electrode pairs in the flexible electrode cap according to the touch electrode response information; performing projection matching on the sensitive field matrix based on the initial voltage data of the electrode pairs to obtain projection matching information; performing model training based on the projection matching information and the tensile deformation data of the flexible electrode cap to obtain a voltage feature-space coordinate mapping relationship and parsing the induced voltage data of the electrode pairs to obtain the corresponding target coordinate information. The above method monitors voltage changes in real time through the flexible electrode cap and parses to obtain coordinate information, thereby improving the accuracy and stability of the positioning process.

[0070] The embodiment of the present invention further provides a head space positioning device based on electrical impedance imaging, which is configured in a positioning and analysis terminal; the head space positioning device based on electrical impedance imaging is used to perform any embodiment of the head space positioning method based on electrical impedance imaging. Specifically, please refer to Figure 5 , Figure 5 A schematic block diagram of a head space positioning device based on electrical impedance imaging provided by an embodiment of the present invention.

[0071] like Figure 5 As shown, the head space positioning device 100 based on electrical impedance imaging includes a three-dimensional model construction module 110, a three-dimensional grid model acquisition module 120, an electric field distribution calculation module 130, a sensitive field matrix acquisition module 140, a projection matching information acquisition module 150, a regression model construction module 160 and a target coordinate information acquisition module 170.

[0072] The three-dimensional model construction module 110 is configured to construct a corresponding three-dimensional model based on the image segmentation information of the individual user and the basic parameters of the flexible electrode cap. The three-dimensional mesh model acquisition module 120 is configured to perform finite element meshing on the three-dimensional model to obtain a three-dimensional mesh model. The electric field distribution calculation module 130 is configured to calculate the electric field distribution of the sampling points in the three-dimensional mesh model according to preset calculation rules to obtain corresponding touch electrode response information. The sensitive field matrix acquisition module 140 is configured to generate a sensitive field matrix corresponding to the sampling points and the electrode pairs in the flexible electrode cap based on the touch electrode response information. The projection matching information acquisition module 150 is configured to perform projection matching on the sensitive field matrix based on the initial voltage data of the electrode pairs to obtain projection matching information; the initial voltage data is the voltage data of the electrode pairs at each position of the flexible electrode cap when the stylus touches them. The regression model construction module 160 is configured to perform model training based on the projection matching information and the tensile deformation data of the flexible electrode cap to obtain a regression model based on the voltage feature-spatial coordinate mapping relationship. The target coordinate information acquisition module 170 is used to analyze the induced voltage data of the electrode pair according to the regression model to obtain corresponding target coordinate information; the induced voltage data is the voltage data of the electrode pair when the stylus touches a certain position in the flexible electrode cap.

[0073] The head space positioning device based on electrical impedance imaging provided in the embodiment of the present invention is used to execute the above-mentioned head space positioning method based on electrical impedance imaging, construct a corresponding three-dimensional model according to the basic parameters of the flexible electrode cap; perform finite element meshing on the three-dimensional model to obtain a three-dimensional mesh model; perform electric field distribution calculation on the sampling points in the three-dimensional mesh model according to preset calculation rules to obtain corresponding touch electrode response information; generate a sensitive field matrix corresponding to the sampling points and the electrode pairs in the flexible electrode cap according to the touch electrode response information; perform projection matching on the sensitive field matrix based on the initial voltage data of the electrode pair to obtain projection matching information; perform model training based on the projection matching information and the tensile deformation data of the flexible electrode cap to obtain a voltage feature-space coordinate mapping relationship and analyze the induced voltage data of the electrode pair to obtain the corresponding target coordinate information. The above method monitors voltage changes in real time through the flexible electrode cap and parses to obtain coordinate information, thereby improving the accuracy and stability of the positioning process.

[0074] The present application also discloses a head space positioning system based on electrical impedance imaging, such as Figure 6As shown, the system includes a positioning and analysis terminal 20, a touch pen 8 and a flexible electrode cap 6; the touch pen 8 is equipped with an excitation unit 7, and the edge of the flexible electrode cap 6 is provided with a ring electrode array composed of multiple electrode pairs; the positioning and analysis terminal 20 is equipped with a communication unit 9, an interaction unit 10, a power supply unit 11, a control unit 1, a data acquisition unit 5, a sensitive field modeling unit 4, a touch pen position reconstruction unit 2 and a visualization unit 3; the communication unit 9, the interaction unit 10, the power supply unit 11, the sensitive field modeling unit 4 and the touch pen position reconstruction unit 2 are all It is communicatively connected to the control unit 1, and the control unit 1 is also communicatively connected to the excitation unit 7; the stylus position reconstruction unit 2 is communicatively connected to the sensitive field modeling unit 4 and the visualization unit 3; the data acquisition unit 5 is communicatively connected to the sensitive field modeling unit 4, the annular electrode array and the excitation unit 7 respectively; the positioning and analysis terminal is internally configured with a memory, and when the positioning and analysis terminal executes the program stored in its internal memory, the positioning and analysis terminal can execute the steps included in the head space positioning method based on electrical impedance imaging.

[0075] The data acquisition unit collects voltage signals from the annular electrode array on the electrode cap and features an anti-interference design to detect weak signals. The data acquisition unit is also connected to the excitation unit to receive the synchronous trigger signal generated by the stylus touching the electrode cap.

[0076] like Figure 4 As shown, the flexible electrode cap 6 is worn on the head similar to a traditional EEG cap. Specifically, it is made of a layered combination of an electrode array 64, conductive fiber sutures 63, conductive silicone 62, and soft fabric 61. In this embodiment, the conductive fiber sutures 63 sew and secure the electrode array 64 and the conductive silicone 62 together, with a layer of soft fabric 61 positioned underneath. The conductive silicone 62 is a stretchable conductive material, with electrode pairs arranged in a circular pattern around its edge, forming a circular electrode array. The soft fabric 61 directly contacts the scalp to enhance wearing comfort, adapt to head deformation, and maintain electrical contact stability.

[0077] Specific application process such as Figure 2 As shown, the subject wears a flexible electrode cap, and data is collected when the stylus touches the top of the electrode cap. When the stylus of this embodiment contacts the flexible electrode cap, different electric field distributions and real-time coordinates are generated at different positions on the head. The positioning analysis terminal with a visualization unit on the right side can visualize the acquired target coordinate information in real time.

[0078] The excitation unit is used to transmit the excitation trigger state. It can send a synchronous trigger signal containing frequency parameters and current intensity parameters to the data acquisition unit through its own wireless communication module to ensure the timing consistency of current excitation and voltage measurement.

[0079] The stylus pen includes a contact detection module, which integrates a pressure sensing unit and an electrode impedance detection unit. When the contact pressure between the pen tip and the electrode cap reaches a set threshold and the contact impedance is lower than a critical value, the driving excitation unit generates a synchronous trigger signal.

[0080] In a preferred embodiment of the present invention, the stylus position reconstruction unit is used to analyze the data collected by the data acquisition unit, and convert the spatial position of the stylus into the voltage distribution of the electrode array when the stylus applies excitation current at different positions of the electrode cap.

[0081] The stylus position reconstruction unit can solve the position information based on the stylus position solution method, as follows: first, the flexible electrode cap is worn on the subject's head, and the flexible electrode cap containing the electrode array is connected to the acquisition front-end module of the data acquisition unit. After the connection, the stylus is placed at the relevant position of the electrode cap, and the trigger module of the acquisition unit receives the trigger signal. The data acquisition unit will collect the electrode pair voltage data under the excitation of the stylus unit, and then transmit it to the stylus position reconstruction unit for data processing. FPGA hardware is used to accelerate data processing. According to the sensitive field matrix obtained by the sensitive field modeling unit, the position solution time is shortened in combination with a fast matching algorithm or a lightweight machine learning model. At the same time, the deformation parameters of the voltage change at the edge of the electrode cap are extracted, and the positioning error caused by the deformation is dynamically corrected and compensated. Finally, the specific position (X, Y, Z) of the stylus on the electrode cap at this time is given.

[0082] The visualization unit is used to display the electric field generated by the stylus at different positions on the electrode cap in real time, as well as the stylus's real-time coordinates. It can use high-performance graphics interfaces such as OpenGL or Vulkan for 3D rendering, combined with a user-friendly GUI (graphical user interface), to achieve intuitive operation and visualization.

[0083] The power supply unit is used to provide energy for the system operation, and is mainly composed of a power conditioning circuit, adopting a modular power supply system, including circuit modules such as an AC / DC conversion module, a DC / DC voltage regulator module, and a backup battery pack.

[0084] The communication unit is used for the system to communicate with the outside world. The communication mode is wired communication or wireless Bluetooth WIFI communication. Wired communication uses Ethernet or USB interface, and wireless communication uses Wi-Fi or Bluetooth module.

[0085] The interactive unit is used for users to set and interact with system functions, wherein the interactive method adopts an interactive interface including a liquid crystal touch screen, an LED display, buttons and touch keys, and provides operation guidance and system feedback through an intuitive user interface.

[0086] In another embodiment of the present invention, a computer-readable storage medium is provided. The computer-readable storage medium may be volatile or non-volatile. The computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps included in the above-described method for spatial head positioning based on electrical impedance imaging.

[0087] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described equipment, devices and units can refer to the corresponding processes in the aforementioned method embodiments, and will not be repeated here. Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented with electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in terms of function in the above description. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0088] In the several embodiments provided by the present invention, it should be understood that the disclosed devices, apparatuses and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, or units with the same function may be combined into one unit. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interfaces, devices or units, or may be an electrical, mechanical or other form of connection.

[0089] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected according to actual needs to achieve the objectives of the embodiments of the present invention.

[0090] In addition, the functional units in the various embodiments of the present invention may be integrated into a single processing unit, each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0091] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the portion that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a computer-readable storage medium and includes several instructions for causing a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned computer-readable storage medium includes various media that can store program code, such as a USB flash drive, a mobile hard drive, a read-only memory (ROM), a magnetic disk, or an optical disk.

[0092] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and such modifications or substitutions are intended to be within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. A head spatial positioning method based on electrical impedance tomography, characterized in that: The method is applied to a positioning and analysis terminal, wherein a data acquisition unit in the positioning and analysis terminal is respectively connected to a stylus and a flexible electrode cap to realize data information transmission, wherein the flexible electrode cap covers the outer surface of a three-dimensional head model, and the method includes: Constructing a corresponding three-dimensional model based on the image segmentation information of the individual user and the basic parameters of the flexible electrode cap; Performing finite element meshing on the three-dimensional model to obtain a three-dimensional mesh model; Calculating the electric field distribution of the sampling points in the three-dimensional grid model according to preset calculation rules to obtain corresponding touch electrode response information; generating a sensitive field matrix corresponding to the sampling points and the electrode pairs in the flexible electrode cap according to the touch electrode response information; Performing projection matching on the initial voltage data of the electrode pairs and the sensitive field matrix to obtain projection matching information; the initial voltage data is voltage data of the electrode pairs at various positions of the flexible electrode cap when the stylus touches the electrode pairs; Performing model training based on the projection matching information and the tensile deformation data of the flexible electrode cap to obtain a regression model based on a voltage feature-space coordinate mapping relationship; The induced voltage data of the electrode pair is analyzed according to the regression model to obtain corresponding target coordinate information; the induced voltage data is voltage data of the electrode pair when the stylus touches a certain position in the flexible electrode cap.

2. The head spatial positioning method based on electrical impedance tomography according to claim 1, characterized in that: The performing finite element meshing on the three-dimensional model to obtain a three-dimensional mesh model includes: Meshing the sensing area of the three-dimensional model according to a preset finite element model to obtain corresponding meshing information; Determining the three-dimensional coordinate position of each grid according to the position parameters of each grid in the grid division information; The grid division information and the three-dimensional coordinate position are added to the three-dimensional model to obtain a corresponding three-dimensional grid model.

3. The head spatial positioning method based on electrical impedance tomography according to claim 1 or 2, characterized in that: The electric field distribution calculation is performed on the sampling points in the three-dimensional grid model according to a preset calculation rule to obtain corresponding touch electrode response information, including: Performing spatial electric potential calculation on the three-dimensional grid model according to the calculation rules and the basic parameters to obtain corresponding spatial electric potential distribution information; The voltage response value of the electrode pair adjacent to each sampling point when the sampling point contacts the stylus is acquired according to the spatial potential distribution information to obtain the touch electrode response information.

4. The head spatial positioning method based on electrical impedance tomography according to claim 3, characterized in that: The analyzing the induced voltage data of the electrode pair according to the regression model to obtain corresponding target coordinate information includes: Extracting corresponding voltage vector features from the induced voltage data; The voltage vector feature is mapped according to the voltage feature-space coordinate mapping relationship in the regression model to obtain the corresponding initial coordinate position as the corresponding target coordinate information.

5. The head spatial positioning method based on electrical impedance tomography according to claim 4, characterized in that: After mapping the voltage vector feature according to the voltage feature-space coordinate mapping relationship in the regression model to obtain the corresponding initial coordinate position through analysis, the method further includes: The initial coordinate position is position compensated according to a preset position compensation strategy and the induced voltage data to obtain a corresponding compensated coordinate position as the target coordinate information.

6. The head spatial positioning method based on electrical impedance tomography according to claim 5, characterized in that: The performing position compensation on the initial coordinate position according to the preset position compensation strategy and the induced voltage data to obtain a corresponding compensated coordinate position as the target coordinate information includes: Acquiring voltage gradient change information at an edge position in the induced voltage data; Performing compensation calculation on the voltage gradient change information according to the position compensation strategy to obtain a corresponding position compensation value; Position compensation is performed on the initial coordinate position according to the position compensation value to obtain a corresponding compensated coordinate position.

7. The head spatial positioning method based on electrical impedance tomography according to claim 6, characterized in that: The method further comprises: Receiving brain image data of an individual user, and performing segmentation processing on the brain image data according to a preset segmentation model to obtain corresponding initial segmentation information; The initial segmentation information is segmented and optimized according to a preset segmentation optimization model to obtain corresponding image segmentation information; the image segmentation information is used as basic data for constructing the three-dimensional head model.

8. A head space positioning device based on electrical impedance imaging, characterized in that: The device is configured in a positioning and analysis terminal, wherein a data acquisition unit in the positioning and analysis terminal is respectively connected to a stylus and a flexible electrode cap to realize data information transmission, wherein the flexible electrode cap covers the outer surface of a three-dimensional head model, and the device is used to perform the head spatial positioning method based on electrical impedance imaging according to any one of claims 1 to 7, and the device comprises: A three-dimensional model construction module, configured to construct a corresponding three-dimensional model based on the image segmentation information of the individual user and the basic parameters of the flexible electrode cap; A three-dimensional mesh model acquisition module is used to perform finite element meshing on the three-dimensional model to obtain a three-dimensional mesh model; an electric field distribution calculation module, configured to calculate the electric field distribution of the sampling points in the three-dimensional grid model according to preset calculation rules to obtain corresponding touch electrode response information; A sensitive field matrix acquisition module, configured to generate a sensitive field matrix corresponding to the sampling points and the electrode pairs in the flexible electrode cap according to the touch electrode response information; a projection matching information acquisition module, configured to perform projection matching on the sensitive field matrix according to the initial voltage data of the electrode pairs to obtain projection matching information; the initial voltage data being the voltage data of the electrode pairs at various positions in the flexible electrode cap touched by the stylus; A regression model building module, configured to perform model training based on the projection matching information and the tensile deformation data of the flexible electrode cap to obtain a regression model based on a voltage feature-space coordinate mapping relationship; The target coordinate information acquisition module is used to analyze the induced voltage data of the electrode pair according to the regression model to obtain corresponding target coordinate information; the induced voltage data is the voltage data of the electrode pair when the stylus touches a certain position in the flexible electrode cap.

9. A head spatial positioning system based on electrical impedance imaging, characterized in that: The system includes a positioning and analysis terminal, a touch pen and a flexible electrode cap; The stylus is provided with an excitation unit, and the edge of the flexible electrode cap is provided with a ring electrode array consisting of a plurality of electrode pairs; The positioning and analysis terminal is equipped with a communication unit, an interaction unit, a power supply unit, a control unit, a data acquisition unit, a sensitive field modeling unit, a stylus position reconstruction unit and a visualization unit; The communication unit, the interaction unit, the power supply unit, the sensitive field modeling unit, and the stylus position reconstruction unit are all in communication connection with the control unit, and the control unit is also in communication connection with the excitation unit; The stylus position reconstruction unit is in communication with the sensitive field modeling unit and the visualization unit; the data acquisition unit is in communication with the sensitive field modeling unit, the annular electrode array and the excitation unit respectively; The positioning and analysis terminal is internally configured with a memory. When the positioning and analysis terminal executes the program stored in its internal memory, the steps of the head spatial positioning method based on electrical impedance imaging described in any one of claims 1 to 7 are implemented.

10. 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 head spatial positioning method based on electrical impedance imaging are implemented as described in any one of claims 1 to 7.

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