An electrical impedance imaging system

Abstract

This invention discloses a power impedance imaging system, comprising at least two electrode strips and a controller, with adjacent electrode strips elastically connected. Each electrode strip includes multiple electrodes arranged in an array. The controller is electrically connected to each electrode. The controller is used to provide electrical signals to the electrodes or to receive feedback electrical signals from the electrodes. When each electrode strip is fixed to the surface of the body to be tested, the controller is configured to determine the excitation electrical signal provided to the electrodes based on the inter-strip spacing between adjacent electrode strips. The technical solution provided by this invention can improve the imaging resolution and clarity of the power impedance imaging system, thereby improving image quality.

Description

Technical Field

[0001] This invention relates to the field of biomedical electrical impedance imaging technology, and more particularly to an electrical impedance imaging system. Background Technology

[0002] Electrical Impedance Tomography (EIT) is a novel imaging technique that infers the conductivity, dielectric constant, and impedance of a part of the body from measurements taken using surface electrodes, and then uses this information to create a photographic image of that area. This technique offers advantages such as non-invasiveness, repeatability, low cost, and functional imaging, making it widely applicable in fields such as biomedicine, agricultural geology, and industrial inspection.

[0003] Electrical impedance tomography (EIT) reconstructs images of the body's conductivity or impedance distribution by applying small alternating currents (typically ranging from a few kHz to hundreds of kHz) to the body surface and then measuring the voltage differences between multiple locations. In the medical field, EIT can be used to monitor the functional status of organs such as the lungs and heart, as well as detect changes in the morphology and properties of muscle tissue. In general, the basic principle of EIT involves the following processes: 1) Current injection: The EIT system contains an electrode ring encircling a part of the body. Current is injected into the body through one or more selected pairs of electrodes; this current is a safe, small-amplitude alternating current that will not cause harm. 2) Voltage measurement: As the current passes through different tissues, different voltage drops are created due to the different conductivities of these tissues (e.g., muscle, fat, blood, and air have different conductivities). Other electrodes are used to measure these voltage changes. 3) Data acquisition: In a complete scan, current is injected through different electrode combinations, and the corresponding voltage responses are recorded. This process generates a large number of voltage-current data points, called boundary measurement data. 4) Image reconstruction: Using mathematical models to convert boundary measurement data into estimates of the internal conductivity distribution.

[0004] Electrical impedance imaging (EIA) systems typically consist of multiple electrodes attached to the surface of the body under test. Test electrical signals are transmitted through the electrodes to the surface, and imaging information is obtained via feedback electrodes. However, in existing EIA systems, the distance between the electrodes and the spacing between adjacent electrode strips can vary with different body surface sizes. This causes repeated changes in the equivalent impedance paths between electrode strips and between them, resulting in blurry imaging information under the same excitation, which is detrimental to observation. Therefore, improving the imaging quality of EIA systems has become a pressing technical problem that needs to be solved. Summary of the Invention

[0005] This invention provides an electrical impedance imaging system that can improve the imaging resolution and clarity of the electrical impedance imaging system, thereby improving the imaging quality.

[0006] This invention provides a power impedance imaging system, comprising:

[0007] At least two electrode strips, with adjacent electrode strips elastically connected; each electrode strip comprises a plurality of electrodes arranged in an array.

[0008] A controller is electrically connected to each of the electrodes; the controller is used to provide electrical signals to the electrodes, or to receive feedback electrical signals from the electrodes.

[0009] When each of the electrode strips is fixed to the surface of the body to be tested, the controller is configured to determine the excitation electrical signal to be provided to the electrode based on the inter-strip spacing between two adjacent electrode strips.

[0010] Optionally, the controller is specifically configured as follows:

[0011] Obtain the first mapping relationship between the spacing and the electrical signal;

[0012] The excitation electrical signal is determined based on the inter-band spacing and the first mapping relationship.

[0013] Optionally, the controller is specifically configured as follows:

[0014] Obtain the type of the body surface to be detected;

[0015] Based on the inter-band spacing and the impedance value of the type, determine the inter-band impedance value between two adjacent electrode bands;

[0016] The excitation signal is determined based on the inter-band impedance value and the preset current.

[0017] Optionally, the controller is specifically configured as follows:

[0018] Calculate the average value of each of the inter-band impedance values, and use this average value as the reference impedance value;

[0019] The excitation signal is determined based on the reference impedance value and the preset current.

[0020] Optionally, the controller is specifically configured to use the product of the inter-band impedance value and the preset current as the excitation electrical signal.

[0021] Optionally, when each of the electrode strips is not fixed to the surface of the body to be tested, the electrode strip has a circular structure and the diameter of the electrode strip is d1;

[0022] When the electrode strip is fixed to the surface of the body to be tested, the diameter of the electrode strip is d2, and the electrodes are arranged at equal intervals.

[0023] Where d2≥d1.

[0024] Optionally, the electrode strip may further include a highly elastic fabric and multiple electrode wires;

[0025] Each of the electrodes is fixed at equal intervals on the surface of the high-elasticity fabric, and each of the electrode lines is electrically connected to each of the electrodes and the controller, respectively.

[0026] Optionally, the high-elasticity fabric is used to connect two adjacent electrode strips.

[0027] Optionally, the electrode comprises silver chloride.

[0028] The technical solution provided by this invention achieves three-dimensional electrical impedance tomography by setting at least two electrode strips, with adjacent electrode strips elastically connected. Each electrode strip includes multiple electrodes arranged in an array. A controller is electrically connected to each electrode. When each electrode strip is fixed to the surface of the body to be tested, the controller is configured to determine the excitation electrical signal supplied to the electrodes based on the inter-strip spacing between adjacent electrode strips. This ensures that the current flowing between the electrode strips is a fixed value under the action of the excitation electrical signal, allowing the feedback electrical signal from the electrodes to accurately reflect the image information beneath the surface of the body to be tested. This improves the imaging resolution and clarity of the electrical impedance tomography system, thereby enhancing the imaging quality. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the structure of an electrical impedance imaging system provided in an embodiment of the present invention. Detailed Implementation

[0030] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0031] Figure 1 This is a schematic diagram of the structure of a power impedance imaging system provided in an embodiment of the present invention, as shown below. Figure 1 As shown, the electrical impedance imaging system 100 includes at least two electrode strips 10 and a controller 20: two adjacent electrode strips 10 are elastically connected; the electrode strip 10 includes a plurality of electrodes 11 arranged in an array; the controller 20 is electrically connected to each electrode 11; the controller 20 is used to provide electrical signals to the electrodes 11, or to receive feedback electrical signals from the electrodes 11; when each electrode strip 10 is fixed to the surface of the body to be detected, the controller 20 is configured to determine the excitation electrical signal provided to the electrodes 11 based on the inter-strip spacing between two adjacent electrode strips 10.

[0032] The electrode strip 10 is an elastic electrode strip with strong elastic deformation capability, which can be fitted onto different body surfaces to be tested, such as the lower leg or arm, and can be used in specific applications according to actual needs, without specific limitations here. The strip spacing represents the distance between two adjacent electrode strips 10, which can be obtained by measuring tools such as a tape measure or vernier caliper, and then manually input into the controller 20; alternatively, the strip spacing can be obtained by using a 3D printed bracket for distance determination, so that the controller 20 can perform corresponding operations. The excitation electrical signal includes a voltage signal or a current signal, and the feedback electrical signal includes a current signal or a voltage signal.

[0033] Specifically, before each electrode strip 10 is fitted onto the surface of the body to be tested, the spacing h1 between each electrode strip 10 is fixed. After each electrode strip 10 is fitted onto the surface of the body to be tested, the spacing between two adjacent electrode strips 10 changes due to differences in the contour or size of the surface. Compared to the initial spacing, the changed spacing may become larger or smaller. Different spacings result in different equivalent impedance paths and equivalent impedance values ​​between the two electrode strips 10. The excitation electrical signal provided to each electrode can be adjusted according to the current inter-strip spacing so that the current flowing between the two electrode strips 10 after the excitation electrical signal is provided to the surface of the body to be tested through the electrodes is a fixed value. In this way, image information about the area below the surface of the body to be tested can be obtained through the feedback electrical signal fed back by the electrode 11, thereby improving the imaging resolution and imaging clarity.

[0034] It should be noted that, Figure 1 The diagram only shows the electrical impedance imaging system 100 including two elastically connected electrode strips 10, namely a first electrode strip 101 and a second electrode strip 102. In other optional embodiments, the electrical impedance imaging system 100 may also include three or more electrode strips 10, which can be set according to actual needs, and no specific limitation is made here.

[0035] It is understood that by setting the electrical impedance imaging system 100 to include multiple electrode strips 10, the electrical impedance imaging system 100 can achieve three-dimensional imaging. The number of electrodes 11 included in each electrode strip 10 can be set according to actual needs. For example, each electrode strip 10 includes 160 electrodes 11, but it can also be other types, which are not specifically limited here.

[0036] The technical solution of this invention achieves three-dimensional electrical impedance tomography by setting at least two electrode strips, with adjacent electrode strips elastically connected. Each electrode strip includes multiple electrodes arranged in an array. A controller is electrically connected to each electrode. When each electrode strip is fixed to the surface of the body to be tested, the controller is configured to determine the excitation electrical signal supplied to the electrodes based on the inter-strip spacing between adjacent electrode strips. This ensures that the current flowing between the electrode strips is a fixed value under the action of the excitation electrical signal, allowing the feedback electrical signal from the electrodes to accurately reflect the image information beneath the surface of the body to be tested. This improves the imaging resolution and clarity of the electrical impedance tomography system, thereby enhancing the imaging quality.

[0037] Optionally, the controller 20 is specifically configured to: acquire a first mapping relationship between the spacing and the electrical signal; and determine the excitation electrical signal based on the inter-band spacing and the first mapping relationship.

[0038] The first mapping relationship can be a graph of the spacing and the electrical signal or a table of the spacing and the electrical signal, which can be obtained through experiments or experience.

[0039] Specifically, when the first mapping relationship is a curve of spacing versus electrical signal, after obtaining the current inter-band spacing, the electrical signal on the curve corresponding to the current inter-band spacing can be directly determined as the excitation signal by referring to the curve of spacing versus electrical signal. Alternatively, when the first mapping relationship is a correspondence table of spacing and electrical signal, after obtaining the current inter-band spacing, the electrical signal corresponding to the current inter-band spacing can be directly obtained by looking up the table and determined as the excitation signal.

[0040] Optionally, the controller 20 is specifically configured to: acquire the type of the current object surface to be detected; determine the inter-band impedance value between two adjacent electrode bands 10 based on the inter-band spacing and the impedance value of the type; and determine the excitation electrical signal based on the inter-band impedance value and the preset current.

[0041] The data type can include muscle, bone, or fat, and the preset current can be a fixed or variable value, which can be set according to actual needs; no specific limitation is made here. Optionally, determining the excitation signal based on the inter-band impedance value and the preset current includes using the product of the inter-band impedance value and the preset current as the excitation signal, which can be obtained according to Ohm's law.

[0042] Specifically, the impedance value varies depending on the type of the object surface to be detected. The controller 20 stores the impedance values ​​corresponding to each type. The product of the impedance value and the inter-band spacing is used as the inter-band impedance value. The product of the inter-band impedance value and the preset current is used as the required excitation signal. This excitation signal is a voltage signal. Under the action of this excitation signal, the current flowing between two adjacent electrode bands 10 is a preset current or close to a preset current. This makes the feedback signal intensity of the electrodes 11 consistent or similar, avoiding excessively strong or weak feedback signals from some electrodes 11. The current can pass through the object surface to be detected more evenly, reducing the boundary concentration effect and making the influence of internal impedance changes on voltage more significant, thus improving imaging quality.

[0043] For example, the impedance value corresponding to subcutaneous fat is 2500 Ω / cm, that of muscle is 333 Ω / cm, and that of bone is 5000 Ω / cm. The impedance values ​​for the same body surface area at different ages may also vary. In other optional embodiments, the age of the subject to be detected can be obtained, and the specific interband impedance value can be calculated based on the impedance values ​​for each type at that age, which can further improve imaging quality.

[0044] Optionally, the controller 20 is specifically configured to: calculate the average value of each inter-band impedance value, use the average value as a reference impedance value; and determine the excitation signal based on the reference impedance value and a preset current.

[0045] Specifically, when the electrical impedance imaging system 100 includes three or more electrode strips 10, the impedance value between each strip can be calculated separately. Since the spacing between each electrode strip 10 is inconsistent, the impedance values ​​between each strip may be different. The average value of the inter-strip impedance value can be used as the reference impedance value. Under the action of the excitation signal determined according to the reference impedance value and the preset current, the current flowing through each electrode strip 10 is consistent or the difference is small, thereby improving the imaging resolution and imaging quality.

[0046] Optionally, when the electrode strips 10 are not fixed to the surface of the body to be tested, the electrode strips 10 are circular structures with a diameter of d1; when the electrode strips 10 are fixed to the surface of the body to be tested, the diameter of the electrode strips 10 is d2, and the electrodes 11 are arranged at equal intervals; wherein, d2≥d1.

[0047] Specifically, when each electrode strip 10 is not fixed to the surface of the object to be tested, each electrode strip 10 is in a contracted state. When each electrode strip 10 is fixed to the surface of the object to be tested, some electrode strips 10 may be in a stretched state, while others may remain in a contracted state. The diameter d2 of the electrode strip 10 after being fixed to the surface of the object to be tested is greater than or equal to the diameter d1 when it is not fixed to the surface of the object to be tested. This allows the electrode strip 10 to be stably fitted onto the surface of the object to be tested, increasing the contact area between the electrode 11 on the electrode strip 10 and the surface of the object to be tested, thereby improving the reliability of the excitation electrical signal application and the reliability of the feedback signal reception.

[0048] Optionally, the electrode strip 10 may also include a high-elasticity fabric and a plurality of electrode wires 12; each electrode 11 is fixed at equal intervals on the surface of the high-elasticity fabric, and each electrode wire 12 is electrically connected to each electrode 11 and the controller 20 respectively.

[0049] The high-elasticity fabrics include materials such as natural rubber, neoprene rubber, silicone, and spandex, which can be configured according to actual needs.

[0050] Specifically, high-elasticity fabrics possess characteristics such as high elastic recovery rate, high fatigue strength, and aging resistance. High-elasticity fabrics typically employ multi-layer composite materials; for example, a surface layer covered with a polytetrafluoroethylene film enhances abrasion resistance, a middle layer embedded with aramid fibers strengthens tensile strength, and an inner layer made of skin-friendly non-woven fabric improves contact comfort. By positioning electrodes 11 on the surface of the high-elasticity fabric, the spacing between electrodes 11 remains consistent before and after stretching, eliminating the need for adjustment of their positions and improving ease of use. Each electrode 11 is located on one side of the high-elasticity fabric, while electrode wires 12 are located on the other side. Electrode wires 12 can be electrically connected to electrodes 11 via soldering or other methods. Electrode wires 12 can also be wound around the back of electrodes 11 before contacting them, increasing the contact area and improving the reliability of electrical signal transmission.

[0051] Optionally, a high-elasticity fabric is used to connect two adjacent electrode strips 10.

[0052] Specifically, before being applied to different surfaces to be tested, the spacing between the electrodes 11 on the electrode strip 10 is a fixed value. After being applied to different surfaces to be tested, the high-elasticity fabric located between the electrode strips 10 has a certain tensile deformation property, which causes the spacing between the electrode strips 10 and the high-elasticity fabric between the electrode strips 10 to also be stretched to adapt to different surfaces to be tested and improve the user experience.

[0053] Optionally, electrode 11 includes silver chloride.

[0054] Among them, silver chloride has a low probability of generating polarization voltage under DC or low-frequency AC power, and polarization voltage will interfere with the accuracy of impedance detection; silver chloride can stabilize the interface potential and improve the signal-to-noise ratio; silver chloride can effectively reduce the contact resistance when electrode 11 contacts the surface of the object to be tested, improve the current injection efficiency, and high contact resistance will lead to signal attenuation. Silver chloride can stabilize the interface reaction, increase the current penetration depth, and improve the resolution of three-dimensional imaging.

[0055] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, combinations, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A power impedance imaging system, characterized in that, include: At least two electrode strips, with adjacent electrode strips elastically connected; each electrode strip comprises a plurality of electrodes arranged in an array. The controller is electrically connected to each of the electrodes. The controller is used to provide electrical signals to the electrode, or to receive feedback electrical signals from the electrode; When each of the electrode strips is fixed to the surface of the body to be tested, the controller is configured to: determine the excitation electrical signal to be provided to the electrode based on the inter-strip spacing between two adjacent electrode strips; Specifically, the controller is configured as follows: Obtain the type of the body surface to be detected; Based on the inter-band spacing and the impedance value of the type, determine the inter-band impedance value between two adjacent electrode bands; The excitation signal is determined based on the inter-band impedance value and the preset current.

2. The electrical impedance imaging system according to claim 1, characterized in that, The controller is specifically configured as follows: Calculate the average value of each of the inter-band impedance values, and use the average value as the reference impedance value; The excitation signal is determined based on the reference impedance value and the preset current.

3. The electrical impedance imaging system according to claim 1, characterized in that, The controller is specifically configured to use the product of the inter-band impedance value and the preset current as the excitation electrical signal.

4. The electrical impedance imaging system according to claim 1, characterized in that, When the electrode strips are not fixed to the surface of the body to be tested, the electrode strips are circular and the diameter of the electrode strips is d1. When the electrode strip is fixed to the surface of the body to be tested, the diameter of the electrode strip is d2, and the electrodes are arranged at equal intervals. Where d2≥d1.

5. The electrical impedance imaging system according to claim 1, characterized in that, The electrode strip also includes a high-elasticity fabric and multiple electrode wires; Each of the electrodes is fixed at equal intervals to the surface of the high-elasticity fabric, and each of the electrode lines is electrically connected to each of the electrodes and the controller, respectively.

6. The electrical impedance imaging system according to claim 5, characterized in that, The high-elasticity fabric is used to connect two adjacent electrode strips.

7. The electrical impedance imaging system according to claim 1, characterized in that, The electrode comprises silver chloride.

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