Electrical impedance imaging device calibration method and storage medium

Abstract

The application relates to an electrical impedance imaging device calibration method and a storage medium, wherein the electrical impedance imaging device calibration method comprises the following steps: acquiring multiple channel data in a measurement area; the measurement area is an area where a known impedance analog load is located; each channel corresponds to a pair of excitation electrodes and a pair of measurement electrodes; the excitation electrodes and the measurement electrodes are connected to the known impedance analog load; for each channel and each frequency in a preset frequency range, based on the channel data and a preset target current, an excitation current injected into the excitation electrodes is calibrated by adjusting a current configuration command to obtain an excitation calibration result; the excitation calibration result comprises a current configuration command under a corresponding frequency, a corresponding channel and a corresponding target current. Through the application, the problem of poor consistency of imaging results is solved.

Description

Technical Field

[0001] This application relates to the field of electrical impedance tomography, and in particular to calibration methods and storage media for electrical impedance tomography equipment. Background Technology

[0002] Electrical Impedance Tomography (EIT) is a novel non-invasive medical functional imaging technique. Its core principle involves arranging an electrode array on the human body surface, injecting a safe alternating current, and measuring the surface voltage signal between the electrodes. By utilizing the relationship between voltage and current, the distribution or changes in the body's internal electrical impedance can be reconstructed, thereby enabling visual monitoring of the functional state of biological tissues. However, as a high-precision device, EIT systems have inherent hardware deviations, which can cause inconsistencies between the actual output excitation current and the set target current, leading to poor consistency in imaging results.

[0003] Currently, no effective solution has been proposed to address the problem of poor consistency in imaging results in related technologies. Summary of the Invention

[0004] This application provides a calibration method and storage medium for electrical impedance imaging equipment to at least solve the problem of poor consistency of imaging results in related technologies.

[0005] In a first aspect, embodiments of this application provide a calibration method for an electrical impedance imaging device, the method comprising:

[0006] Acquire data from multiple channels within a measurement region; the measurement region is the area where a simulated load of known impedance is located; each channel corresponds to a pair of excitation electrodes and a pair of measurement electrodes; the excitation electrodes and the measurement electrodes are connected to the simulated load of known impedance.

[0007] For each channel and each frequency within a preset frequency range, based on the channel data and the preset target current, the excitation current injected into the excitation electrode is calibrated by adjusting the current configuration command to obtain the excitation calibration result; the excitation calibration result includes the current configuration command at the corresponding frequency, corresponding channel, and corresponding target current.

[0008] In some embodiments, the step of calibrating the excitation current injected into the excitation electrode based on the channel data and a preset target current by adjusting the current configuration command to obtain an excitation calibration result includes:

[0009] Based on the channel data and the preset gain factor, the actual voltage is obtained;

[0010] Based on the actual voltage and the preset known impedance, the actual output current is obtained;

[0011] Based on the target current and the actual output current, the excitation current injected into the excitation electrode is calibrated by adjusting the current configuration command to obtain the excitation calibration result.

[0012] In some embodiments, the step of calibrating the excitation current injected into the excitation electrode based on the target current and the actual output current by adjusting the current configuration command to obtain the excitation calibration result includes:

[0013] If the actual output current is greater than the target current, the current value of the current configuration command is reduced until the actual output current equals the target current.

[0014] The excitation calibration result is obtained based on the current configuration command at the current frequency, current channel, and current target current.

[0015] In some embodiments, the step of calibrating the excitation current injected into the excitation electrode by adjusting the current configuration command based on the target current and the actual output current to obtain the excitation calibration result further includes:

[0016] If the actual output current is less than the target current, increase the current value of the current configuration command until the actual output current equals the target current.

[0017] The excitation calibration result is obtained based on the current configuration command at the current frequency, current channel, and current target current.

[0018] In some embodiments, after obtaining the excitation calibration result, the method further includes:

[0019] Based on the excitation calibration results, for each frequency within the preset frequency range, the impedance values ​​of the known impedance simulated load at multiple specified locations are changed to obtain the imaging results at the specified locations.

[0020] The imaging results are calibrated by adjusting the preset imaging display dynamic range parameters of the imaging tool components to obtain imaging calibration results.

[0021] In some embodiments, the step of changing the impedance value of the known impedance simulated load at multiple specified locations for each frequency within the preset frequency range, based on the excitation calibration result, to obtain the imaging result at the specified locations, includes:

[0022] Based on the excitation calibration results, for each frequency within a preset frequency range, the impedance value of the known impedance simulated load at multiple specified locations is changed to generate the impedance change at the specified locations.

[0023] Based on the impedance change at the specified location, the imaging result at the specified location is obtained.

[0024] In some embodiments, the step of adjusting the preset imaging display dynamic range parameter of the imaging tool component to calibrate the imaging result and obtain an imaging calibration result includes:

[0025] Adjust the imaging display dynamic range parameter of the imaging tool component so that the impedance change at the specified location corresponds to a preset number of pixels in the imaging result;

[0026] The imaging calibration result is obtained based on the imaging display dynamic range parameters at the current frequency and the current specified position.

[0027] In some embodiments, the step of changing the impedance value of the known impedance simulated load at multiple specified locations for each frequency within the preset frequency range, based on the excitation calibration result, to generate an impedance change at the specified locations, includes:

[0028] Based on the current configuration command in the excitation calibration result, for each frequency within the preset frequency range, the excitation electrode is controlled to inject the excitation current into the known impedance simulated load;

[0029] By changing the impedance value of the known impedance simulated load at multiple specified locations, the impedance change at the specified locations under the action of the excitation current is generated.

[0030] In some embodiments, adjusting the imaging display dynamic range parameter of the imaging tool component so that the impedance change at the specified location corresponds to a preset number of pixels in the imaging result includes:

[0031] When the number of pixels in the imaging result where the impedance change at the specified location is greater than the preset number, the lower limit of the imaging display dynamic range parameter is increased and / or the upper limit of the imaging display dynamic range parameter is decreased until the number of pixels in the imaging result where the impedance change is greater than the preset number.

[0032] When the number of pixels in the imaging result where the impedance change at the specified location is less than the preset number, the lower limit of the imaging display dynamic range parameter is lowered and / or the upper limit of the imaging display dynamic range parameter is raised until the number of pixels in the imaging result where the impedance change matches the preset number.

[0033] Secondly, embodiments of this application provide a storage medium storing a computer program that, when executed by a processor, implements the electrical impedance imaging device calibration method as described in the first aspect above.

[0034] Compared to related technologies, the electrical impedance imaging device calibration method and storage medium provided in this application acquire multiple channel data in the measurement area; the measurement area is the region where a known impedance simulated load is located; each channel corresponds to a pair of excitation electrodes and a pair of measurement electrodes; the excitation electrodes and measurement electrodes are connected to the known impedance simulated load; for each channel and each frequency within a preset frequency range, based on the channel data and a preset target current, the excitation current injected into the excitation electrode is calibrated by adjusting the current configuration command to obtain the excitation calibration result; the excitation calibration result includes the current configuration command at the corresponding frequency, corresponding channel, and corresponding target current, thus solving the problem of poor consistency of imaging results.

[0035] Details of one or more embodiments of this application are set forth in the following drawings and description to make other features, objects and advantages of this application more readily apparent. Attached Figure Description

[0036] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0037] Figure 1 This is a hardware structure block diagram of a terminal for a calibration method of an electrical impedance imaging device according to an embodiment of this application;

[0038] Figure 2 This is a flowchart of a calibration method for an electrical impedance imaging device according to an embodiment of this application;

[0039] Figure 3 This is a schematic diagram of a simulated load with known impedance according to an embodiment of this application;

[0040] Figure 4 This is a schematic diagram of a measurement load circuit according to an embodiment of this application;

[0041] Figure 5 This is a flowchart of another electrical impedance imaging device calibration method according to an embodiment of this application;

[0042] Figure 6 According to the embodiments of this application, the same amount of impedance change is presented in a consistent imaging display at different frequencies and different locations of impedance change;

[0043] Figure 7 This is an impedance variation distribution diagram according to an embodiment of this application;

[0044] Figure 8 This is a structural block diagram of a calibration device for electrical impedance imaging according to an embodiment of this application. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of this application clearer, the application is described and illustrated below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the application. All other embodiments obtained by those skilled in the art based on the embodiments provided in this application without inventive effort are within the scope of protection of this application. Furthermore, it is understood that although the efforts made in such a development process may be complex and lengthy, for those skilled in the art related to the content disclosed in this application, modifications to design, manufacturing, or production based on the technical content disclosed in this application are merely conventional technical means and should not be construed as insufficient disclosure of the content of this application.

[0046] In this application, the reference to "embodiment" means that a specified feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments without conflict.

[0047] Unless otherwise defined, the technical or scientific terms used in this application shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms “a,” “an,” “an,” “the,” and similar words used in this application do not indicate quantity limitation and may indicate singular or plural. The terms “comprising,” “including,” “having,” and any variations thereof used in this application are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or device that includes a series of steps or modules (units) is not limited to the listed steps or units, but may also include steps or units not listed, or may include other steps or units inherent to these processes, methods, products, or devices. The terms “connected,” “linked,” “coupled,” and similar words used in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. “Multiple” used in this application means two or more. “And / or” describes the relationship between related objects, indicating that three relationships may exist; for example, “A and / or B” can represent: A alone, A and B simultaneously, and B alone. The terms “first,” “second,” “third,” etc., used in this application are merely to distinguish similar objects and do not represent a specific ordering of the objects.

[0048] The method embodiments provided in this example can be executed on a terminal, computer, or similar computing device. Taking running on a terminal as an example, Figure 1 This is a hardware structure block diagram of a terminal for a calibration method of an electrical impedance imaging device according to an embodiment of this application. For example... Figure 1 As shown, a terminal may include one or more ( Figure 1 Only one is shown in the diagram. A processor 102 (which may include, but is not limited to, a microprocessor MCU or a programmable logic device FPGA, etc.) and a memory 104 for storing data are also shown. Optionally, the terminal may further include a transmission device 106 for communication functions and an input / output device 108. Those skilled in the art will understand that... Figure 1 The structure shown is for illustrative purposes only and does not limit the structure of the terminal described above. For example, the terminal may also include components that are more... Figure 1 The more or fewer components shown, or having the same Figure 1 The different configurations shown.

[0049] The memory 104 can be used to store computer programs, such as application software programs and modules, like the computer program corresponding to the electrical impedance tomography device calibration method in this embodiment. The processor 102 executes various functional applications and data processing by running the computer program stored in the memory 104, thereby implementing the above-described method. The memory 104 may include high-speed random access memory and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 104 may further include memory remotely located relative to the processor 102, and these remote memories can be connected to the terminal via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0050] The transmission device 106 is used to receive or send data via a network. Specific examples of the network described above may include a wireless network provided by the terminal's communication provider. In one example, the transmission device 106 includes a Network Interface Controller (NIC), which can connect to other network devices via a base station to communicate with the Internet. In another example, the transmission device 106 may be a Radio Frequency (RF) module used for wireless communication with the Internet.

[0051] EIT, or bioelectrical impedance tomography, is a novel medical functional imaging technique. It works by placing a number of electrodes on the human body surface, injecting a safe current, and measuring the surface voltage of the other electrodes. The relationship between voltage and current is used to reconstruct the internal electrical impedance value or its change. Because this method does not use radionuclides or radiation, it is harmless to the human body, allowing for repeated measurements and offering fast imaging speeds and functional imaging capabilities. EIT technology has many advantages, such as being non-invasive, posing no ionizing or radiation hazards, having a simple system structure, and being easy to measure. It can be used for rapid, portable imaging and has broad application prospects in the continuous dynamic image monitoring of physiological activities in the cardiovascular system, esophagus, and stomach.

[0052] However, as high-precision equipment, EIT systems have inherent hardware deviations, leading to discrepancies in the final output and imaging results. Different devices testing the same impedance-changing target (due to chip and circuit errors) will also produce inconsistent imaging results. Similarly, the same device using different excitation signals to test the same impedance-changing target will produce different imaging results (due to frequency response variations, and inconsistencies in the magnitude of the excitation and received signals at different frequencies). This phenomenon can easily cause confusion or inconvenience for users, requiring operators to understand the principles of EIT technology for proper use, thus increasing the operational threshold.

[0053] Based on this, this embodiment provides a calibration method for electrical impedance imaging equipment. Figure 2 This is a flowchart of a calibration method for an electrical impedance imaging device according to an embodiment of this application, such as... Figure 2 As shown, the process includes the following steps:

[0054] Step S201: Acquire multiple channel data in the measurement area; the measurement area is the region where the known impedance simulated load is located; each channel corresponds to a pair of excitation electrodes and a pair of measurement electrodes; the excitation electrodes and measurement electrodes are connected to the known impedance simulated load.

[0055] First, multiple electrodes need to be connected to a simulated load with known impedance. Typically, an array of 16 electrodes is used. These electrodes are evenly distributed around the circumference of the simulated load according to the rule of 16 equal parts, forming a closed measurement loop. Each electrode can either act as an excitation electrode to inject excitation current into the load or as a measurement electrode to collect voltage signals. Each channel corresponds to a pair of excitation electrodes and a pair of measurement electrodes. All electrodes establish a stable electrical connection with the simulated load with known impedance through dedicated electrode lines.

[0056] The preset known impedance simulated load is the core reference for calibration, and its impedance characteristics (including the basic impedance value, adjustable impedance variation amount, and variation position) have been precisely calibrated. For example, please refer to... Figure 3 The load contains multiple designated positions, numbered 1-5, each with a preset fixed impedance change. The overall impedance frequency response characteristics within the preset full operating frequency band (e.g., 10kHz-200kHz) are known, enabling the simulation of impedance changes in human tissue at different frequencies.

[0057] During the calibration of electrical impedance imaging equipment, it is first necessary to acquire data from multiple channels within the measurement area. This measurement area is specifically the region where a simulated load with known impedance is located. The impedance characteristics of this simulated load (including the basic impedance value, adjustable impedance variation, and variation position) have been precisely calibrated to provide a stable and traceable benchmark for calibration. Each channel corresponds to a pair of excitation electrodes and a pair of measurement electrodes. The excitation electrodes are used to inject excitation current into the simulated load with known impedance, while the measurement electrodes are used to acquire channel data (such as voltage signals) generated by the load under the action of the excitation current. All excitation electrodes and measurement electrodes are stably connected to the simulated load with known impedance through dedicated electrode lines to ensure effective transmission of the excitation signal and accurate acquisition of the measurement signal.

[0058] Step S202: For each channel and each frequency within a preset frequency range, based on channel data and a preset target current, the excitation current injected into the excitation electrode is calibrated by adjusting the current configuration command to obtain the excitation calibration result; the excitation calibration result includes the current configuration command at the corresponding frequency, corresponding channel, and corresponding target current.

[0059] The current configuration command is a parameter used by the device to control the output current of the excitation electrode. Its core function is to correct the deviation between the actual output current and the target current by adjusting the command, ultimately achieving accurate calibration of the excitation current. During the excitation current calibration of the electrical impedance imaging device, it is necessary to cover every channel of the device and all frequency points within the preset operating frequency band (e.g., 10kHz–200kHz). For calibration of each channel at each frequency, the actual voltage is first calculated based on the channel data and the preset gain factor. Then, the actual output current is derived by combining the impedance value of the simulated load with the preset known impedance. The deviation between the actual output current and the target current is then used to determine the accuracy. If the actual output current differs from the target current, the excitation current injected into the excitation electrode is calibrated by adjusting the current configuration command until the actual output current matches the target current. The resulting excitation calibration result specifically includes the accurate current configuration command for that frequency, that channel, and the corresponding target current, providing a foundation for subsequent excitation consistency across devices and frequencies.

[0060] Steps S201 to S202 above acquire multiple channel data of the region where the known impedance simulated load is located, and for each channel and each frequency within a preset frequency range, adjust the current configuration command based on the channel data and the preset target current to calibrate the excitation current, obtaining the excitation calibration result of the current configuration command under the corresponding frequency, channel, and target current. This can eliminate the problem of inconsistency between the actual output current and the target current caused by inherent hardware deviations (such as chip errors and circuit errors) and signal frequency response characteristics of the EIT device, thereby solving the problem of poor consistency of imaging results caused by this, ensuring that different devices output the same excitation current at the same frequency and the same channel, while ensuring the accuracy of the excitation current of the same device at different frequencies.

[0061] In some embodiments, based on channel data and a preset target current, the excitation current injected into the excitation electrode is calibrated by adjusting the current configuration command to obtain excitation calibration results, including:

[0062] The actual voltage is obtained based on the channel data and the preset gain factor;

[0063] The actual output current is obtained based on the actual voltage and the preset known impedance;

[0064] Based on the target current and the actual output current, the excitation current injected into the excitation electrode is calibrated by adjusting the current configuration command to obtain the excitation calibration result.

[0065] First, the actual voltage is calculated using the acquired channel data (such as voltage signals) and a preset receiver gain factor. This step ensures the accuracy of the voltage data by clarifying the gain effect of the signal during transmission and amplification.

[0066] Next, based on the obtained actual voltage and the preset impedance value of the simulated load with known impedance, the actual output current is derived according to Ohm's law. Please refer to [link / reference]. Figure 4 Its calculation formula can be expressed as:

[0067] I out =(V r / G) / R load ;

[0068] Among them, I out V represents the actual output current. r The voltage signal received at the digital terminal, where G is the receiver gain factor, and R... load Given the impedance, the actual current output of the device can be precisely quantified.

[0069] Finally, the calculated actual output current is compared with the preset target current. If the actual output current is greater than the target current, the current value of the current configuration command is reduced. If the actual output current is less than the target current, the current value of the current configuration command is increased until the actual output current matches the target current. At this point, the frequency, channel, and current configuration command under the corresponding target current are recorded as the final excitation calibration result.

[0070] For different target currents, the above calibration steps need to be repeated until all target currents are calibrated to ensure that the excitation current output accuracy of the corresponding frequency and channel meets the consistency requirements under each target current. Table 1 shows the relationship between the current configuration command and the actual output current.

[0071] Table 1 Relationship between current configuration command and actual output current

[0072]

[0073] The above steps calculate the actual voltage based on channel data and a preset gain factor, derive the actual output current by combining the preset known impedance, and adjust the current configuration command according to the deviation between the target current and the actual output current to complete the excitation current calibration. This accurately quantifies the impact of inherent hardware deviations (such as chip and circuit errors) and signal frequency response characteristics on the excitation current. Through a closed-loop adjustment mechanism, the actual output current is kept consistent with the target current. The final excitation calibration result ensures that each channel can output accurate excitation current at each frequency within the preset frequency range. This achieves consistency of excitation current for different devices at the same frequency and the same channel, and also ensures the accuracy of excitation current for the same device at different frequencies. This lays a core foundation for the cross-device and cross-frequency consistency of subsequent imaging results and effectively reduces the operational threshold caused by excitation signal deviation.

[0074] In some embodiments, based on the target current and the actual output current, the excitation current injected into the excitation electrode is calibrated by adjusting the current configuration command to obtain excitation calibration results, including:

[0075] If the actual output current is greater than the target current, reduce the current value of the current configuration command until the actual output current equals the target current.

[0076] The excitation calibration results are obtained based on the current configuration command at the current frequency, current channel, and current target current.

[0077] Specifically, when the calculated actual output current is greater than the preset target current, the current value corresponding to the current configuration command is reduced. This adjustment will be applied to the current output of the excitation electrode in real time. At the same time, the change of the actual output current is continuously monitored through the channel data of the known impedance simulated load until the actual output current is completely consistent with the target current. At this time, the current frequency, the current channel, and the current configuration command corresponding to the current target current are recorded as the excitation calibration result in this scenario.

[0078] In the above steps, by reducing the current value of the current configuration command when the actual output current is greater than the target current until the actual output current is equal to the target current, and recording the current configuration command corresponding to the current frequency, channel, and target current as the excitation calibration result, the problem of excessive excitation current output caused by inherent hardware deviations (such as chip errors and circuit errors) and signal frequency response characteristics is accurately eliminated. This ensures the accuracy of the excitation current at specific frequencies and channels, provides a guarantee for different devices to output consistent excitation current at the same frequency and channel, and for the same device to maintain the stability of the excitation current at different frequencies. This lays a key foundation for the cross-device and cross-frequency consistency of subsequent imaging results and reduces the operational threshold caused by current deviation.

[0079] In some embodiments, based on the target current and the actual output current, the excitation current injected into the excitation electrode is calibrated by adjusting the current configuration command to obtain an excitation calibration result, and the method further includes:

[0080] If the actual output current is less than the target current, increase the current value of the current configuration command until the actual output current equals the target current.

[0081] The excitation calibration results are obtained based on the current configuration command at the current frequency, current channel, and current target current.

[0082] Specifically, when the actual output current is less than the preset target current, the current value corresponding to the current configuration command is increased. This adjustment is fed back to the current output stage of the excitation electrode in real time. At the same time, the change of the actual output current is continuously monitored through the measurement channel until the actual output current is completely matched with the target current. At this time, the system will record the current frequency, the current channel, and the current configuration command corresponding to the current target current as the excitation calibration result in this scenario.

[0083] In the above steps, by increasing the current value of the current configuration command when the actual output current is less than the target current until the actual output current is equal to the target current, and recording the current configuration command corresponding to the current frequency, channel, and target current as the excitation calibration result, the problem of insufficient excitation current output caused by inherent hardware deviations (such as chip errors and circuit errors) and signal frequency response characteristics is accurately compensated. This ensures the accuracy of the excitation current at specific frequencies and channels. Together with the adjustment logic when the actual output current is greater than the target current, it forms a complete closed-loop calibration mechanism, further ensuring the consistency of excitation current of different devices at the same frequency and channel, as well as the stability of excitation current of the same device at different frequencies. This lays a solid foundation for the consistency of imaging results across devices and frequencies, and reduces the operational complexity caused by current deviations.

[0084] In some embodiments, another method for calibrating electrical impedance imaging devices is provided. Figure 5 This is a flowchart of another electrical impedance imaging device calibration method according to an embodiment of this application, such as... Figure 5 As shown, the process includes Figure 2 The steps S201 and S202 shown herein also include the following steps:

[0085] Step S501: Based on the excitation calibration results, for each frequency within a preset frequency range, change the impedance value of the known impedance simulated load at multiple specified locations to obtain the imaging results at the specified locations.

[0086] Step S502: Adjust the preset imaging display dynamic range parameters of the imaging tool component to calibrate the imaging results and obtain the imaging calibration results.

[0087] Specifically, based on the calibrated excitation current output logic, for each frequency within a preset frequency range (e.g., 10kHz–200kHz), the impedance values ​​at multiple specified locations (e.g., locations 1-5) on a known impedance simulated load are changed (injecting a preset fixed impedance change). This allows the system to generate impedance change signals at these specified locations under the action of an accurate excitation current, thereby reconstructing the imaging results at the corresponding locations. Subsequently, for these imaging results, the imaging display dynamic range parameters (including the upper and lower limits of the color bar) of preset imaging tool components (e.g., a pseudo-color image and a matching color bar for displaying the imaging results) are adjusted. By quantifying the mapping relationship between color and impedance change, the same impedance change is made to present a consistent visual representation in imaging results at different frequencies and different specified locations (e.g., all corresponding to 20 pixels; see [link to documentation]). Figure 6 This process ultimately yields imaging calibration results containing dynamic range parameters for each frequency and specified location. For different excitation currents, the above calibration steps must be repeated until all excitation currents are calibrated.

[0088] In the above steps, after obtaining the excitation calibration result, based on the result, for each frequency within the preset frequency range, the impedance value of the known impedance simulated load at multiple specified locations is changed to obtain the imaging result at the corresponding location. The imaging display dynamic range parameter of the imaging tool component is adjusted to calibrate the imaging result to obtain the imaging calibration result. This process, through standardized imaging display logic, compensates for the imaging visual deviation caused by differences in device hardware or frequency characteristics. It effectively solves the problem of inconsistent imaging results of the same device at different frequencies or between different devices for the same impedance change target caused by inherent deviations in device hardware and differences in signal frequency response characteristics (such as different imaging sizes at the same location). It ensures that the imaging display of the same impedance change amount under different frequencies and different excitation currents has consistency (such as all corresponding to a preset number of pixels), reduces the usage threshold for operators, and makes the imaging results more comparable and reliable. Together with excitation calibration, it achieves cross-device and cross-frequency EIT device consistency and imaging consistency.

[0089] In some embodiments, based on the excitation calibration results, for each frequency within a preset frequency range, the impedance values ​​of a known impedance simulated load at multiple specified locations are changed to obtain imaging results at the specified locations, including:

[0090] Based on the excitation calibration results, for each frequency within a preset frequency range, the impedance values ​​of a known impedance simulated load at multiple specified locations are changed to generate the impedance change at the specified locations.

[0091] Based on the impedance change at a specified location, the imaging result at that location is obtained.

[0092] Specifically, based on the excitation calibration results (i.e., the accurate current configuration commands corresponding to each frequency and channel), for each frequency within a preset frequency range (e.g., 10kHz–200kHz), the impedance values ​​at multiple specified locations (e.g., locations 1-5) on the known impedance simulated load are changed to generate a preset, fixed impedance change (e.g., impedance change caused by injecting the same perturbation target), thereby simulating the dynamic impedance changes of human tissue in actual applications.

[0093] Subsequently, under the action of a calibrated excitation current, the system reconstructs the imaging results at the corresponding locations based on the impedance changes at these designated locations and the signals collected by the electrodes.

[0094] The above steps, based on the excitation calibration results (accurate current configuration commands corresponding to each frequency and channel), change the impedance value of the known impedance simulated load at multiple specified locations for each frequency within the preset frequency range to generate a fixed impedance change, and obtain the imaging result at the corresponding location based on this change. This process generates a known impedance change signal under standardized excitation conditions, providing a unified benchmark for the calibration of subsequent imaging display parameters, ensuring that the imaging results can accurately reflect the location and amplitude characteristics of the impedance change, and laying a data foundation for achieving imaging consistency across frequencies and devices.

[0095] In some embodiments, the imaging results are calibrated by adjusting the preset imaging display dynamic range parameters of the imaging tool component to obtain imaging calibration results, including:

[0096] Adjust the imaging display dynamic range parameter of the imaging tool component so that the impedance change at a specified location corresponds to a preset number of pixels in the imaging result.

[0097] The imaging calibration results are obtained based on the imaging display dynamic range parameters at the current frequency and the current specified location.

[0098] Specifically, for the imaging results generated by simulating the impedance change at a specified location of a load with known impedance, the imaging display dynamic range parameters of the imaging tool components (such as the pseudo-color image and the accompanying color bar used to present the imaging results) are adjusted (including the upper and lower limits of the color bar, etc., to quantify the mapping relationship between color and impedance change). This ensures that the impedance change at the specified location precisely corresponds to a preset number of pixels in the imaging result (e.g., to stably display a specific impedance change as 20 pixels in the image). Based on this, the imaging display dynamic range parameters at the current frequency and the current specified location are recorded and saved as the imaging calibration results for this scenario. In an electrical impedance imaging system, the imaging results are typically displayed as a pseudo-color image. The color bar plays a crucial role alongside this image, its core function being to provide a numerical scale, which is the most basic and important function of the color bar. Different colors (pseudo-color) on the EIT image represent the relative change in impedance (or conductivity) within the reconstructed region. The color bar quantifies and visualizes this color mapping relationship. It clearly indicates the specific impedance change value or percentage corresponding to each color (or color range) on the image. For example, one end of the Colorbar (e.g., red) might be marked -30%, indicating that the impedance in that area has decreased by 30% relative to the reference value (e.g., the average impedance at the end of expiration); the other end (e.g., blue) might be marked +20%, indicating that the impedance has increased by 20%; and the middle color (e.g., green) might be marked 0%, indicating that it is close to the reference value. Please refer to [link / reference]. Figure 7The curve in the figure is a distribution of impedance change. The horizontal axis represents the relative position of the test target (e.g., the origin is the chest and the farthest point is the back), and the vertical axis is the impedance change relative to the reference frame obtained by the test. By calibrating the Colorbar, the number of pixels greater than the dashed line is a preset number (e.g., 20).

[0099] In the above steps, by adjusting the imaging display dynamic range parameter of the imaging tool component, the impedance change at a specified location corresponds to a preset number of pixels in the imaging result. Based on the parameter at the current frequency and the current specified location, the imaging calibration result is obtained. This process eliminates the visual deviation caused by differences in device hardware or frequency characteristics (such as different imaging sizes at different frequencies due to impedance changes at the same location) by standardizing the correspondence between impedance changes and the number of imaging pixels. It ensures that the imaging display of the same impedance change at different frequencies and different specified locations has a unified pixel scale standard, realizes visual consistency of imaging results across frequencies and devices, reduces the threshold for operators to rely on the technical principles of the equipment, and makes the imaging results more comparable and reliable. Together with excitation calibration, it ensures the consistency of EIT equipment and the accuracy of multi-frequency imaging.

[0100] In some embodiments, based on the excitation calibration results, for each frequency within a preset frequency range, the impedance values ​​of a known impedance simulated load at multiple specified locations are changed to generate impedance changes at the specified locations, including:

[0101] Based on the current configuration command in the excitation calibration results, for each frequency within the preset frequency range, control the excitation electrode to inject excitation current into the simulated load with known impedance;

[0102] By changing the impedance values ​​of a known load at multiple specified locations, the impedance change at the specified locations under the action of excitation current is generated.

[0103] Specifically, based on the current configuration command in the excitation calibration results, for each frequency within the preset frequency range (such as 10kHz–200kHz), the excitation electrode is first controlled by the current configuration command to inject a precise excitation current into the simulated load with known impedance. This step relies on the standardized current output logic formed by the previous excitation calibration to ensure that the injected excitation current is consistent with the target current at different frequencies.

[0104] Subsequently, by changing the impedance values ​​at multiple specified locations (such as locations 1-5) on the known impedance simulated load, these locations are made to produce quantifiable impedance changes under the action of the aforementioned precise excitation current, thereby generating the impedance change amount (such as a preset fixed change amount) at the corresponding specified location.

[0105] In the above steps, based on the current configuration command in the excitation calibration result, the excitation electrode is controlled to inject a precise excitation current into the known impedance simulated load for each frequency within the preset frequency range. The impedance values ​​at multiple specified locations of the load are changed to generate the impedance change at the corresponding location under the action of the excitation current. This ensures that the impedance change generated under standardized excitation conditions is repeatable and consistent. It eliminates the interference of inaccurate excitation current caused by inherent hardware deviations or signal frequency response characteristics on the measurement of impedance change. Furthermore, by using the fixed position of the known load and the preset impedance change, the impedance change signals generated under different frequencies and different devices have a unified benchmark, providing stable and comparable input data for subsequent imaging calibration. This lays the data foundation for achieving consistent imaging results across devices and frequencies, effectively solving the imaging deviation problem caused by inconsistent signal input in the prior art.

[0106] In some embodiments, adjusting the imaging display dynamic range parameter of the imaging tool component so that the impedance change at a specified location corresponds to a preset number of pixels in the imaging result includes:

[0107] When the number of pixels in the imaging result where the impedance change at a specified location is greater than the preset number, the lower limit of the imaging display dynamic range parameter is increased and / or the upper limit of the imaging display dynamic range parameter is decreased until the number of pixels in the imaging result where the impedance change is greater than the preset number.

[0108] When the number of pixels in the imaging result where the impedance change at a specified location is less than the preset number, the lower limit of the imaging display dynamic range parameter is lowered and / or the upper limit of the imaging display dynamic range parameter is raised until the number of pixels in the imaging result where the impedance change matches the preset number.

[0109] Specifically, when the number of pixels corresponding to a specified location in the imaging result generated by simulating the impedance change at a known impedance load exceeds a preset number, the system will adjust the lower limit of the imaging display dynamic range parameter upwards and / or the upper limit downwards. This operation reduces the pixel coverage area corresponding to low and high impedance change signals by compressing the dynamic range, thereby reducing the pixel scale occupied by the impedance change at the specified location in the imaging. Conversely, when the number of pixels corresponding to the impedance change at the specified location in the imaging result is less than the preset number, the lower limit of the imaging display dynamic range parameter will be lowered and / or the upper limit will be raised. By expanding the dynamic range, the pixel mapping coverage of the impedance change signal will be increased, thus increasing the number of pixels at that location. The above adjustments will continue until the number of pixels corresponding to the impedance change at the specified location in the imaging result completely matches the preset number. The above steps precisely control the mapping relationship between impedance change and imaging pixel size by finely adjusting the upper and lower limits of the dynamic range. This effectively eliminates the problem of inconsistent pixel counts for the same impedance change in imaging caused by differences in device hardware and frequency characteristics. It ensures that the same impedance change has a uniform visual representation scale in imaging results at different frequencies and specified locations, providing a standardized visual benchmark for comparing imaging results across devices and frequencies, and further improving the consistency and reliability of imaging results.

[0110] This embodiment also provides a calibration device for electrical impedance tomography (EIT) equipment, which is used to implement the above embodiments and preferred embodiments; details already described will not be repeated. As used below, the terms "module," "unit," "subunit," etc., can refer to a combination of software and / or hardware that performs a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0111] Figure 8 This is a structural block diagram of a calibration device for electrical impedance imaging according to an embodiment of this application, such as... Figure 8 As shown, the device includes:

[0112] The channel data acquisition module 81 is used to acquire data from multiple channels in the measurement area; the measurement area is the region where a known impedance analog load is located; each channel corresponds to a pair of excitation electrodes and a pair of measurement electrodes; the excitation electrodes and the measurement electrodes are connected to the known impedance analog load.

[0113] The excitation current calibration module 82 is used to calibrate the excitation current injected into the excitation electrode for each channel and each frequency within a preset frequency range, based on the channel data and the preset target current, by adjusting the current configuration command, and obtain the excitation calibration result; the excitation calibration result includes the current configuration command at the corresponding frequency, corresponding channel and corresponding target current.

[0114] It should be noted that the above modules can be functional modules or program modules, and can be implemented by software or hardware. For modules implemented by hardware, the above modules can reside in the same processor; or the above modules can be located in different processors in any combination. Specific examples in this embodiment can be found in the examples described in the above embodiments and optional implementations, and will not be repeated in this embodiment.

[0115] Furthermore, in conjunction with the electrical impedance imaging device calibration methods in the above embodiments, this application embodiment can provide a storage medium for implementation. This storage medium stores a computer program; when executed by a processor, the computer program implements any of the electrical impedance imaging device calibration methods in the above embodiments.

[0116] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties.

[0117] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments described above. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0118] Those skilled in the art should understand that the technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments have been described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0119] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. An electrical impedance imaging device calibration method, characterized by, The method comprises: acquiring a plurality of channel data in a measurement region; the measurement region is a region where a known impedance analog load is located; each channel corresponds to a pair of excitation electrodes and a pair of measurement electrodes; the excitation electrodes and the measurement electrodes are connected to the known impedance analog load; for each channel and each frequency in a preset frequency range, based on the channel data and a preset target current, adjusting a current configuration command to calibrate an excitation current injected into the excitation electrodes to obtain an excitation calibration result; the excitation calibration result includes a current configuration command under a corresponding frequency, a corresponding channel and a corresponding target current, and comprises: based on the channel data and a preset gain multiple, an actual voltage is obtained; based on the actual voltage and a preset known impedance, an actual output current is obtained; based on the target current and the actual output current, adjusting a current configuration command to calibrate an excitation current injected into the excitation electrodes to obtain the excitation calibration result, comprising: in the case that the actual output current is greater than the target current, the current value of the current configuration command is reduced until the actual output current is equal to the target current; based on the current configuration command under the current frequency, the current channel and the current target current, the excitation calibration result is obtained; in the case that the actual output current is less than the target current, the current value of the current configuration command is increased until the actual output current is equal to the target current; based on the current configuration command under the current frequency, the current channel and the current target current, the excitation calibration result is obtained.

2. The electrical impedance imaging device calibration method of claim 1, wherein, After obtaining the excitation calibration result, the method further comprises: based on the excitation calibration result, for each frequency in the preset frequency range, changing the impedance value of the known impedance analog load at a plurality of specified positions to obtain an imaging result at the specified positions; adjusting the imaging display dynamic range parameter of the preset imaging tool assembly to calibrate the imaging result to obtain an imaging calibration result.

3. The electrical impedance imaging device calibration method of claim 2, wherein, The method based on the excitation calibration result, for each frequency in the preset frequency range, changing the impedance value of the known impedance analog load at a plurality of specified positions to obtain an imaging result at the specified positions, comprises: based on the excitation calibration result, for each frequency in the preset frequency range, changing the impedance value of the known impedance analog load at a plurality of specified positions to generate an impedance change amount at the specified positions; based on the impedance change amount at the specified positions, an imaging result at the specified positions is obtained.

4. The electrical impedance imaging device calibration method of claim 2, wherein, The method of adjusting the imaging display dynamic range parameter of the preset imaging tool assembly to calibrate the imaging result to obtain an imaging calibration result, comprises: adjusting the imaging display dynamic range parameter of the imaging tool assembly, so that the impedance change amount at the specified positions corresponds to a preset number of pixel points in the imaging result; based on the imaging display dynamic range parameter under the current frequency and the current specified position, the imaging calibration result is obtained.

5. The electrical impedance imaging device calibration method of claim 3, wherein, The impedance change amount of the specified position under the action of the excitation current is generated by changing the impedance value of the known impedance analog load at a plurality of the specified positions for each frequency in the preset frequency range based on the excitation calibration result, comprising: Based on the current configuration command in the excitation calibration result, the excitation electrode injects the excitation current into the known impedance analog load for each frequency in the preset frequency range. The impedance change amount of the specified position under the action of the excitation current is generated by changing the impedance value of the known impedance analog load at a plurality of the specified positions for each frequency in the preset frequency range based on the excitation calibration result, comprising:

6. The electrical impedance imaging device calibration method of claim 4, wherein, The imaging display dynamic range parameter of the imaging tool assembly is adjusted so that the impedance change amount of the specified position corresponds to a preset number of pixel points in the imaging result, comprising: When the number of pixel points of the impedance change amount of the specified position in the imaging result is greater than the preset number, the lower limit value of the imaging display dynamic range parameter is adjusted to be higher and / or the upper limit value of the imaging display dynamic range parameter is adjusted to be lower until the number of pixel points of the impedance change amount in the imaging result and the preset number match; When the number of pixel points of the impedance change amount of the specified position in the imaging result is less than the preset number, the lower limit value of the imaging display dynamic range parameter is adjusted to be lower and / or the upper limit value of the imaging display dynamic range parameter is adjusted to be higher until the number of pixel points of the impedance change amount in the imaging result and the preset number match.

7. A storage medium, characterized by The storage medium has a computer program stored therein, wherein the computer program is configured to execute the electrical impedance imaging device calibration method of any one of claims 1-6 when running.

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