Electrode belt rotation measurement method and system for circular field eit imaging

Abstract

The application provides an electrode belt rotation measurement method and system for circular field EIT imaging, comprising: obtaining a measured circular field radius and a circular field radius completely covered by a fixed electrode belt; calculating an electrode coverage rate according to a ratio of the two; determining a reference rotation number of the electrode belt based on the electrode coverage rate; calculating a rotation angle of the electrode belt each time according to the reference rotation number; moving the electrode belt according to the rotation number and the rotation angle to obtain multiple EIT boundary measurement data; and fusing the multiple measurement data and inversely reconstructing a measured field image. The application realizes complete measurement of a larger measured field by rotating a fixed-size electrode belt, avoiding the need to customize an electrode array due to a change in the size of a measured target; meanwhile, the total dimension of the measurement data is reduced by fusing multiple measurement data, thereby reducing the data processing time for solving the inverse problem.

Description

Technical Field

[0001] This invention relates to the field of electrical measurement technology, and specifically to an electrode strip rotation measurement method and system for circular field EIT imaging. Background Technology

[0002] Electrical Impedance Tomography (EIT) is a non-destructive testing technique based on electromagnetic field theory. It offers advantages such as visualization, high temporal resolution, real-time online monitoring, and in-situ detection. During EIT imaging, an electrode array covering the entire surface of the measured area is typically deployed. Safe electrical excitations are applied to some electrodes, and the response electrical signals are measured on the remaining electrodes, thereby reconstructing the conductivity distribution within the measured area. This technology has been widely applied in fields such as industrial multiphase flow detection, medical health monitoring, and structural health monitoring.

[0003] Currently, EIT technology in practical applications often employs fixed electrode arrays customized for the target being measured, covering the entire measured surface area through embedding or other methods. These fixed electrode arrays offer advantages such as high adaptability and good imaging results for specific targets, but they suffer from low flexibility. When the size of the target changes, the electrode array needs to be redesigned and manufactured; when some electrodes experience poor contact or disconnection, the measurement capability may fail to cover the entire measured area, leading to a decrease in imaging quality. For large-sized measured surfaces, a large number of electrodes are typically required to ensure measurement accuracy, resulting in a significant increase in the amount of measurement data. Limited by computer processing power, this significantly increases data processing time, leading to a substantial extension of EIT imaging time.

[0004] Therefore, how to adapt the same electrode strip to circular fields of different sizes under the condition of fixed electrode hardware and number of electrodes, and reduce the dimensionality of measurement data and shorten imaging time, has become a problem that needs to be solved in EIT imaging technology. Summary of the Invention

[0005] To address the issues that fixed electrode arrays cannot adapt to circular fields of different sizes, as well as the high dimensionality and long imaging time of large-size field measurement data, this invention provides an electrode strip rotation measurement method and system for EIT imaging of circular fields.

[0006] In one aspect, the present invention provides an electrode strip rotation measurement method for circular field EIT imaging, comprising: Obtain the radius of the circular field completely covered by the fixed electrode strip and the radius of the circular field being measured The radius of the measured circular field Larger than the radius of the circular field ; Based on the radius of the circular field and the radius of the circular field being measured Calculate electrode coverage F: ; The reference number of electrode band rotations N is determined by rounding down the electrode coverage rate F: ; in, This indicates rounding down to the nearest integer.

[0007] The rotation angle α of the electrode strip for each rotation is determined based on the reference number of rotations N: ; The electrode strip is rotated and moved to various positions according to the rotation angle α; EIT boundary measurements were performed at the initial position and at N rotated positions to obtain N+1 boundary measurement data. The N+1 boundary measurement data are linearly stacked to obtain a boundary measurement value vector; based on the boundary measurement value vector, the conductivity distribution image of the measured field is reconstructed using the EIT inverse problem algorithm.

[0008] This invention provides a unified quantitative index for the coverage of different sized test fields by obtaining the radius of the fixed electrode strip's complete coverage and the radius of the measured field, defining the coverage rate F as the radius ratio. The number of reference rotations N is calculated using the coverage rate F, and rounding down ensures that the coverage area after N rotations is not less than the perimeter of the measured field. Then, the N+1 measurement positions are uniformly covered by the boundary of the circular test field by each rotation angle α. N+1 boundary measurement data are obtained by measuring at the initial position and at the N rotated positions, achieving complete boundary information acquisition of the measured field. The N+1 boundary measurement data are linearly stacked to form a boundary measurement value vector, which preserves complete boundary information while maintaining a lower dimension of measurement data than traditional full-coverage electrode arrays, thus reducing the input dimension for solving the inverse problem. Based on this vector, the EIT inverse problem algorithm is used to reconstruct the conductivity distribution image, enabling image reconstruction of different sized fields without increasing the number of electrodes or hardware acquisition channels. The various features work synergistically: coverage, number of rotations, and rotation angle form a deterministic parameter chain; rotation measurement provides spatial expansion; and linear stacking and inversion reconstruction achieve data dimensionality reduction and image restoration. This solves the problems of low flexibility of fixed electrode arrays and long processing time for large-size measurement data.

[0009] In some preferred embodiments, rotational movement is achieved by driving a fixed electrode strip to rotate around the central axis of the circular field being measured via a motor, or by manual rotation. Motor drive improves the accuracy and repeatability of rotational positioning, while manual rotation is suitable for situations where there is no power source in the field. Both methods ensure that N+1 positions are reached at an angle α.

[0010] In some preferred embodiments, EIT boundary measurement includes: each electrode unit in the fixed electrode strip, controlled by a host computer, sequentially acquiring excitation and response signals according to a preset excitation-response mode. Host computer control enables automated multi-position, multi-channel measurement, reducing manual intervention and improving measurement consistency and acquisition efficiency.

[0011] In some preferred embodiments, the radius, electrode coverage, reference rotation count, and rotation angle are obtained before the initial measurement; or, they are recalculated and updated based on the current parameters after the initial measurement. This setup allows the measurement process to be pre-calculated offline or dynamically adjusted online based on the actual dimensions, enhancing its applicability.

[0012] In some preferred embodiments, the N+1 boundary measurement data are linearly stacked, including: sequentially splicing the corresponding boundary voltage vectors according to the spatial order of the fixed electrode strips at each measurement position. Splicing in spatial order ensures that the fused boundary measurement vector corresponds consistently to the field boundary position, avoiding reconstruction errors caused by data misalignment.

[0013] In some preferred embodiments, the EIT inverse problem algorithm includes a regularized inversion algorithm or an iterative reconstruction algorithm. These algorithms can suppress the ill-conditioned nature of the inverse problem and improve the stability and resolution of the reconstructed image.

[0014] In some preferred embodiments, the fixed electrode strip comprises a plurality of equally spaced electrodes used to apply excitation current and acquire response voltage. The equally spaced arrangement simplifies the design of the excitation-response mode and ensures uniformity of boundary measurement data.

[0015] The present invention also provides an electrode strip rotation measurement system for circular field EIT imaging, the system comprising: The size acquisition module is used to obtain the radius of the circular field completely covered by the fixed electrode strip. and the radius of the circular field being measured The radius of the measured circular field Larger than the radius of the circular field ; The coverage calculation module is used to calculate the coverage based on the radius of the circular field. and the radius of the circular field being measured Calculate the electrode coverage F; The rotation number determination module is used to determine the reference rotation number N of the electrode band based on the electrode coverage rate F, rounded down. The rotation angle determination module is used to determine the rotation angle α of the electrode strip for each rotation based on the reference number of rotations N; The rotation measurement module is used to control the fixed electrode strip to perform EIT boundary measurements at the initial position and at N rotated positions, respectively, to obtain N+1 boundary measurement data. The data fusion and reconstruction module is used to linearly stack the N+1 boundary measurement data to obtain a boundary measurement value vector, and reconstruct the conductivity distribution image of the measured field based on the boundary measurement value vector using the EIT inverse problem algorithm.

[0016] The system and method claims correspond to each other. Each module works together according to the process of parameter calculation, rotation execution and data fusion. Under the condition of fixed electrode hardware, it can realize the complete boundary measurement and image reconstruction of circular fields of different sizes. It has the advantages of good adaptability and low data processing volume.

[0017] Compared with the prior art, the present invention has the following beneficial effects: This invention utilizes a rotating, fixed electrode strip to reconstruct images of measured fields of varying sizes, eliminating the need for the electrode strip to completely cover the measured field, thus achieving EIT image reconstruction. Compared to custom-designed, fully-covering electrode arrays, this application allows for the reuse of multiple measured fields, avoiding the need to customize measurement equipment and sensors when the measured target changes, effectively reducing costs and increasing flexibility. Furthermore, by linearly stacking N+1 measurement data points to obtain a boundary measurement value vector, the dimensionality of the measurement set is effectively reduced when imaging results are similar, thereby reducing the data processing workload of solving the inverse problem and shortening imaging time. The formula chain F, N, and α ensures the integrity and uniformity of the rotational coverage, while the linear stacking and fusion of data guarantees the integrity of the information after dimensionality reduction. The system modules and method steps correspond one-to-one, facilitating engineering implementation. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the electrode strip movement strategy in a circular test field with a radius of 12.5cm in an embodiment of the present invention; Figure 2 The actual distribution of the object field in the measurement model with a radius of 12.5 cm; Figure 3 The image shows a reconstructed image of a 12.5 cm radius measurement model obtained using the conventional 20-electrode full coverage method. Figure 4 The image is a reconstructed image of a measurement model with a radius of 12.5 cm obtained by using a fixed electrode belt rotation measurement method.

[0019] Figure 5This is a schematic diagram of the electrode strip movement strategy in a circular test field with a radius of 20cm in an embodiment of the present invention; Figure 6 The actual distribution of the object field in the measurement model with a radius of 20cm; Figure 7 Image reconstructed from a 20cm radius measurement model obtained using the conventional 32-electrode full coverage method; Figure 8 The image is a reconstruction of a 20cm radius measurement model obtained using a fixed electrode belt rotation measurement method. Figure 9 This is a schematic diagram of the method flow of the present invention.

[0020] Figure label: 1. Initial position of the electrode strip; 2. Position of the electrode strip after one movement; 3. Repeated measurement during the movement of the electrode strip; 4. Position of the electrode strip after two movements. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0022] This invention provides a specific implementation of an electrode strip rotation measurement method for circular field EIT imaging, referring to... Figure 9 This includes the following steps: Step 1: Obtain the radius of the circular field completely covered by the fixed electrode strip. and the radius of the circular field being measured ,in Greater than Step 2, according to and Step 3: Calculate the electrode coverage F; Step 4: Determine the reference rotation number N of the electrode strip based on F rounded down; Step 5: Determine the rotation angle α of the electrode strip for each rotation based on N; Step 6: Perform EIT boundary measurements at the initial position and at the N rotated positions to obtain N+1 boundary measurement data; Step 7: Linearly stack the N+1 boundary measurement data to obtain the boundary measurement value vector; Step 8: Based on the boundary measurement value vector, reconstruct the conductivity distribution image of the measured field using the EIT inverse problem algorithm.

[0023] The above method parameterizes the measurement capability of the fixed electrode strip as the full coverage radius, and determines the number of rotations and rotation angles based on the coverage rate under partial coverage conditions, allowing the electrode strip to sequentially cover different circumferential regions of the measured field in space. The data dependencies between the steps are as follows: Step 1 provides the geometric premise; Step 2 converts the geometric relationship into the coverage rate; Steps 3 and 4 derive discrete rotation parameters from the coverage rate; Step 5 performs spatial expansion measurement; and Steps 6 and 7 integrate the data obtained from the spatial expansion measurement into dimensionality-reduced boundary measurement values ​​and reconstruct the image. Therefore, complete EIT measurements of circular fields of different sizes can be performed without changing the electrode strip hardware.

[0024] In step 1, the radius of the circular field completely covered by the fixed electrode strip is determined. These are known inherent parameters of the electrode strip, which can be calculated by dividing the electrode strip length by 2π, or determined by the radius of the arc formed by the actual installation of the electrode strip. The radius of the circular field being measured. This can be obtained through geometric measurement or calibration. The reason for requiring... Greater than It is because when Not greater than At this time, the fixed electrode strip itself can completely cover the measured field in one go, and there is no need for rotational reuse. This condition limits this method to partial coverage scenarios and forms the basis for the subsequent rotational measurement steps.

[0025] In practice, the geometric parameters input in this step directly determine the rotation strategy. Compared to existing fixed full-coverage electrode arrays, traditional methods require the perimeter of the electrode array to match the perimeter of the measured field. Once the radius of the measured field is larger than the radius covered by the electrode strip, the fixed array cannot be used; however, this method... and As an explicit input, the same electrode band can be used for different The system automatically adjusts subsequent rotation parameters, enabling hardware reuse. This process avoids hardware redesign and manufacturing due to changes in target dimensions, and is particularly suitable for on-site measurement of objects with multiple sizes and batches.

[0026] In step 2, the electrode coverage F is determined according to... and The ratio is calculated as follows: ; The coverage rate is equivalent to the ratio of the length of the fixed electrode strip to the circumference of the circular field being measured. The coverage rate F is a dimensionless quantity, with a value range of 0 < F < 1. The closer F is to 1, the closer the fixed electrode strip is to completely covering the field being measured, and the fewer rotations are required; the smaller F is, the shorter the fixed electrode strip is relative to the field being measured, and the more rotations are required.

[0027] In practical implementation, taking a 16-electrode fixed electrode strip as an example, it perfectly covers a circular field with a radius of 10cm. If the radius of the measured circular field is 12.5cm, then F = 10 / 12.5 = 0.8; if the radius of the measured circular field is 20cm, then F = 10 / 20 = 0.5. It can be seen that the coverage rate F can clearly quantify the degree of coverage of the same electrode strip over fields of different sizes, providing a consistent indicator for calculating rotational parameters. Traditional methods, however, require designing electrode arrays with different perimeters for fields of different sizes, lacking a unified parameterization method.

[0028] In step 3, the reference rotation number N is determined by rounding down the coverage rate F, i.e.: ; in, This indicates rounding down. The formula means that to achieve a total coverage length equal to the perimeter of the measured field, at least 1 / F of the number of rotations is required. Since the number of rotations must be an integer, the largest integer not greater than 1 / F is used. Rounding down ensures that after N rotations, the total coverage length is not less than the perimeter of the measured field, avoiding missing boundary measurement information due to insufficient coverage. Since 0 < F < 1, 1 / F > 1, and N is a positive integer greater than zero.

[0029] This calculation avoids unnecessary additional measurements. Rounding up would add an extra measurement, increasing data volume and imaging time; direct rounding might result in insufficient coverage at certain F values. Therefore, matching rounding down with the boundary condition that the total coverage length is not less than the measured perimeter is key to balancing measurement integrity and data efficiency.

[0030] In step 4, the rotation angle α of the electrode strip for each rotation is determined based on the reference number of rotations N, where: ; Since N rotations correspond to the initial position and N rotated positions, totaling N+1 measurement positions, dividing the 360° into N+1 equal parts ensures that the measurement positions are evenly spaced circumferentially. This allows the electrode strip coverage areas at multiple positions to overlap and form a uniform coverage of the boundary of the measured circular field. Uniform spacing also helps avoid the problem of some circumferential areas being excessively covered while other areas are insufficiently covered.

[0031] In practical implementation, if N=1, then α=360° / (1+1)=180°, meaning the electrode strip only needs to rotate 180° to cover the other half of the circumference, forming two uniformly distributed positions. If N=2, then α=360° / (2+1)=120°, and the electrode strip rotates 120° and 240° sequentially to form three uniformly distributed positions. In contrast, if a non-uniform angle is used, such as rotating 150° and 200° when N=2, although it can also cover the field, it will introduce inconsistent coverage repetition, which may lead to non-uniformity of the reconstructed sensitivity matrix. Therefore, uniform rotation angle is an important condition to ensure that the boundary is approximately uniformly sampled after linear stacking of multiple boundary measurement data.

[0032] In step 5, EIT boundary measurements are performed at the initial position and at N rotated positions, resulting in N+1 boundary measurement data. The EIT boundary measurement at each measurement position includes: applying a safe excitation current to some electrodes according to a preset excitation-response mode, and acquiring response voltages on the remaining electrodes; a complete boundary measurement yields a set of boundary voltage vectors corresponding to that position. The rotation drive device moves the fixed electrode strip sequentially to each position according to the angle α obtained in step 4, and the acquisition process at each position is controlled by the host computer. The N+1 measurements cover all N+1 angular positions.

[0033] In practical implementation, taking the 16-electrode adjacent excitation mode as an example, 16×13 independent boundary measurements can be collected at each position. A set of measurements is taken at the initial position, and then another set is taken after each rotation by an angle α, until N rotations are completed. After all positions are measured, the total number of boundary measurements is N+1. For example, with R_obj=12.5cm, F=0.8, N=1, and α=180°, a total of 2 boundary measurement data are obtained; with R_obj=20cm, F=0.5, N=2, and α=120°, a total of 3 boundary measurement data are obtained. Clearly, this method does not require changing the number of electrodes; a larger measured field can be covered simply by rotation.

[0034] In step 6, the boundary measurement data from N+1 measurements are linearly stacked to obtain a boundary measurement value vector. The physical meaning of linear stacking is to concatenate the boundary voltage vectors obtained at each location in a specific order, forming a higher-dimensional but structurally unified measurement vector. The equivalent measurement coverage corresponding to this vector is greater than any single measurement, approaching the boundary information range obtained from a single measurement using a traditional full-coverage electrode array. Since the number of electrodes used in each measurement is the same, the total dimension of the measurement data is determined by multiplying the dimension of a single measurement by the number of measurements. Linear stacking ensures that boundary information is preserved with a lower data dimension without changing the input format of the reconstruction algorithm.

[0035] In step 7, based on the boundary measurement vector, the conductivity distribution image of the measured field is reconstructed using the EIT inverse problem algorithm. The EIT inverse problem is an ill-conditioned inverse problem, requiring the solution of the conductivity distribution within the field based on the boundary measurement vector and the sensitivity matrix. Commonly used algorithms in this field, such as regularized inversion algorithms and iterative reconstruction algorithms, can be employed. The reconstructed conductivity distribution image is used to observe the distribution state of different media within the measured field.

[0036] In practice, for the boundary measurement vector obtained in step 6, a sensitivity matrix corresponding to the position of each electrode after rotation can be constructed, and then the Tikhonov regularization method can be used to solve for the change in conductivity. The image reconstruction quality of this method is close to that of the traditional full-coverage method, and the imaging results can accurately reflect the position and number of targets in the object field, proving that the rotation multiplexing strategy does not significantly lose imaging quality while reducing hardware scale and data processing volume.

[0037] For the rotational movement in step 5, in one optional implementation, the fixed electrode strip can be rotated around the central axis of the circular field being measured by a motor, or it can be achieved by manual rotation. Motor-driven rotation offers higher positional repeatability and automation, making it suitable for applications requiring multiple repeated measurements; manual rotation is simple in structure and suitable for situations where no power is available on-site. Regardless of the driving method used, as long as the electrode strip can be moved sequentially to N positions at angle α, the measurement effect of this method will not be affected.

[0038] For the EIT boundary measurement in step 5, the host computer can control each electrode unit in the fixed electrode strip to sequentially acquire excitation and response signals according to a preset excitation-response mode. The host computer switches channels sequentially according to the excitation electrode number and the acquisition electrode number, forming a complete frame acquisition process. Host computer control can avoid manual wiring and switching, improving the efficiency and consistency of multi-position, multi-channel measurements.

[0039] Regarding the timing of parameter calculations in steps S1 to S4, all parameter calculations can be completed before the initial measurement, or the initial measurement can be completed first, and then the rotation parameters can be recalculated and updated based on the current parameters. Calculating parameters before the initial measurement is suitable for situations where the dimensions of the measured field are known and do not change during rotation; updating parameters after the initial measurement is suitable for situations where the dimensions of the measured field may change due to deformation, installation errors, etc. Both methods ensure that subsequent rotation measurements match the current measured field.

[0040] For the linear stacking in step 6, the corresponding boundary voltage vectors can be sequentially stitched together according to the spatial order of the fixed electrode strips at each measurement position. For example, the initial position, the position after rotation α, the position after rotation 2α, and so on, up to the position after rotation Nα, can be stitched together sequentially. Spatially sequential stitching ensures that the fused boundary measurement vectors correspond to the spatial positions on the physical boundaries, avoiding misalignment of the sensitivity matrix and measurement vectors due to incorrect stitching order, thus preventing reconstruction errors. The specific stitching order of the linear stacking does not affect the data dimension, but it does affect the accuracy of the position calibration during inversion reconstruction.

[0041] For the EIT inverse problem algorithm in step 7, a regularized inversion algorithm or an iterative reconstruction algorithm can be used. Regularized inversion algorithms suppress ill-conditioned phenomena by introducing prior constraints; a typical example is Tikhonov regularization. Iterative reconstruction algorithms solve for the conductivity distribution through a stepwise approximation method; a typical example is Landweber iteration. Algorithm selection mainly affects image resolution and noise suppression capability, but does not change the data dimensionality reduction effect achieved by this method through rotation reuse and linear stacking. In practical applications, a suitable algorithm can be selected based on the characteristics of the measured field and processing speed requirements.

[0042] The fixed electrode strip itself may optionally include multiple equally spaced electrodes used to apply excitation current and acquire response voltage. Equal spacing simplifies the design of the excitation-response mode, ensures uniform spatial distribution of the electrodes, and helps guarantee data quality for each boundary measurement. The electrode strip can be made of a flexible conductive material to conform to the boundary of a circular field. The number of electrodes can be selected based on the size of the measured field and resolution requirements; for example, 16 electrodes are used in this embodiment, but the invention is not limited to this number.

[0043] The present invention will be further described below with reference to the accompanying drawings and embodiments: Using COMSOL finite element software and MATLAB calculation software, a simulation experiment was conducted on the electrode strip rotation measurement method for circular field EIT imaging proposed in this invention. The experimental scheme is as follows: In this experiment, the fixed electrode belt was set with 16 electrodes, which could completely cover the circular field with a radius of 10cm. The fixed electrode belt rotation measurement method was studied for circular areas of 12.5cm and 20cm. 1. If the measured field is 12.5cm, then the coverage of the fixed electrode strip is 80%. Following the above rotation measurement strategy, the number of rotations N=1, and the rotation angle α=180°. Therefore, the fixed electrode strip needs to be rotated once to achieve complete measurement of this field. Figure 1 As shown, the dimension of the measurement data obtained from two measurements is 2 × 16 × 13 = 416. Regarding... Figure 2The measurement model was used to invert and reconstruct images using both the traditional 20-electrode method that just completely covers the image and the fixed 16-electrode rotating measurement method of this invention. The reconstructed image obtained by the traditional method is shown below. Figure 3 As shown, the reconstructed image obtained by the fixed 16-electrode rotation measurement method of the present invention is as follows: Figure 4 As shown; 2. If the measured field is 20cm, then the coverage of the fixed electrode strip is 50%. Following the above rotation measurement strategy, the number of rotations N=2, and the rotation angle α=120°. Therefore, the fixed electrode strip needs to be rotated twice to achieve complete measurement of this field. Figure 5 As shown, the dimension of the measurement data obtained from three measurements is 3 × 16 × 13 = 624. (Regarding...) Figure 6 The measurement model was used to invert and reconstruct images using both the traditional 32-electrode full-coverage method and the fixed 16-electrode rotating measurement method of this invention. The reconstructed image obtained by the traditional method is shown below. Figure 7 As shown, the reconstructed image obtained by the fixed 16-electrode rotation measurement method of the present invention is as follows: Figure 8 As shown.

[0044] Simulation results show that the electrode rotation measurement method provided by this invention, based on a fixed 16 electrodes and without increasing the number of hardware data acquisition channels, achieves complete coverage of the measured field through rotation. It reconstructs images of the measured field that traditionally requires 20 and 32 electrodes for complete coverage, with minimal loss of image reconstruction quality. This improves the adaptability and flexibility of the EIT system and significantly reduces equipment costs. Furthermore, the data dimension of the traditional 32-electrode complete coverage measurement is 32 × 29 = 928, while the data dimension of the fixed electrode rotation measurement method is 3 × 16 × 13 = 624. The method proposed in this invention reduces the data dimension by 32.76% compared to the traditional scheme, effectively reducing the computational burden and improving computational speed. Simulation experiments verify the excellent performance of the electrode rotation measurement method provided by this invention.

[0045] The present invention also provides an electrode strip rotation measurement system for circular field EIT imaging, the system comprising: The size acquisition module is used to obtain the radius of the circular field completely covered by the fixed electrode strip. and the radius of the circular field being measured The radius of the measured circular field Larger than the radius of the circular field ; The coverage calculation module is used to calculate the coverage based on the radius of the circular field. and the radius of the circular field being measured Calculate the electrode coverage F; The rotation number determination module is used to determine the reference rotation number N of the electrode band based on the electrode coverage rate F, rounded down. The rotation angle determination module is used to determine the rotation angle α of the electrode strip for each rotation based on the reference number of rotations N; The rotation measurement module is used to control the fixed electrode strip to perform EIT boundary measurements at the initial position and at N rotated positions, respectively, to obtain N+1 boundary measurement data. The data fusion and reconstruction module is used to linearly stack the N+1 boundary measurement data to obtain a boundary measurement value vector, and reconstruct the conductivity distribution image of the measured field based on the boundary measurement value vector using the EIT inverse problem algorithm.

[0046] The system and method claims correspond to each other. Each module works together according to the process of parameter calculation, rotation execution and data fusion. Under the condition of fixed electrode hardware, it can realize the complete boundary measurement and image reconstruction of circular fields of different sizes. It has the advantages of good adaptability and low data processing volume.

[0047] The above embodiments are merely illustrative of the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any equivalent substitutions or improvements made based on the technical concept of the present invention should be considered as falling within the scope of protection of the present invention.

Claims

1. A method for measuring electrode strip rotation in circular field EIT imaging, characterized in that, include: Obtain the radius of the circular field completely covered by the fixed electrode strip and the radius of the circular field being measured ,in Greater than ; according to and Calculate electrode coverage F: ； The reference number of electrode band rotations N is determined by rounding down the electrode coverage rate F. ； in, Indicates rounding down; The rotation angle α of the electrode strip for each rotation is determined based on the reference number of rotations N: ； The electrode strip is rotated and moved to the N rotated positions according to the rotation angle α. EIT boundary measurements were performed at the initial position and at N rotated positions to obtain N+1 boundary measurement data. The boundary measurement data of the N+1 times are linearly stacked to obtain the boundary measurement value vector; Based on the boundary measurement vector, the conductivity distribution image of the measured field is reconstructed using the EIT inverse problem algorithm.

2. The method according to claim 1, characterized in that, The rotational movement is achieved by driving the fixed electrode strip to rotate around the central axis of the circular field being measured via a motor, or by manual rotation.

3. The method according to claim 1, characterized in that, The EIT boundary measurement includes: the host computer controlling each electrode unit in the fixed electrode strip to sequentially collect excitation and response signals according to a preset excitation-response mode.

4. The method according to claim 1, characterized in that, The acquisition of radius, calculation of electrode coverage, reference rotation count, and rotation angle are completed before the initial measurement; or, after the initial measurement is completed, they are recalculated and updated based on the current parameters.

5. The method according to claim 1, characterized in that, The step of linearly stacking the N+1 boundary measurement data includes: sequentially splicing the corresponding boundary voltage vectors according to the spatial order of the fixed electrode strip at each measurement position.

6. The method according to claim 1, characterized in that, The EIT inverse problem algorithm includes a regularized inversion algorithm or an iterative reconstruction algorithm.

7. The method according to claim 1, characterized in that, The fixed electrode strip includes multiple electrodes arranged at equal intervals, which are used to apply excitation current and acquire response voltage.

8. An electrode strip rotation measurement system for circular field EIT imaging, characterized in that, include: The size acquisition module is used to obtain the radius of the circular field completely covered by the fixed electrode strip. and the radius of the circular field being measured ,in Greater than ; The coverage calculation module is used to calculate the coverage based on... and Calculate the electrode coverage F; The rotation number determination module is used to determine the reference rotation number N of the electrode band based on the electrode coverage rate F, rounded down. The rotation angle determination module is used to determine the rotation angle α of the electrode strip for each rotation based on the reference number of rotations N; The rotation measurement module is used to control the fixed electrode strip to perform EIT boundary measurements at the initial position and at N rotated positions, respectively, to obtain N+1 boundary measurement data. The data fusion and reconstruction module is used to linearly stack the N+1 boundary measurement data to obtain a boundary measurement value vector, and reconstruct the conductivity distribution image of the measured field based on the boundary measurement value vector using the EIT inverse problem algorithm.

9. The system according to claim 8, characterized in that, The rotation measurement module includes a motor drive unit for driving the fixed electrode strip to rotate around the central axis of the circular field being measured.

10. An electronic device comprising a memory and a processor, the memory storing a computer program, the processor executing the computer program to implement the steps of the method according to any one of claims 1-7.

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