Electrical impedance imaging system

Abstract

The invention discloses an electrical impedance imaging system which comprises at least two electrode bands and a controller, and every two adjacent electrode bands are elastically connected. The electrode band comprises a plurality of electrodes arranged in an array; the controller is electrically connected with each electrode; the controller is used for providing electric signals for the electrodes or receiving feedback electric signals fed back by the electrodes; when the electrode bands are fixed to the body surface to be detected, the controller is configured to determine excitation electric signals provided for the electrodes according to the band spacing between every two adjacent electrode bands. According to the technical scheme provided by the invention, the imaging resolution and the imaging definition of the electrical impedance imaging system can be improved, and the imaging quality is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of biomedical electrical impedance imaging, and in particular to an electrical impedance imaging system. Background Art

[0002] Electrical impedance tomography (EIT) is a novel imaging technique that infers the electrical conductivity, dielectric constant, and impedance of a body part from surface electrode measurements and uses them to generate photographic images of that part. This technique offers advantages such as non-invasiveness, repeatability, low cost, and the ability to provide functional imaging, leading to its widespread application in fields such as biomedicine, agricultural geology, and industrial testing.

[0003] Electrical impedance tomography (EIT) reconstructs an image of the body's electrical conductivity, or impedance distribution, by applying a small alternating current (typically at frequencies ranging from a few kHz to several hundred kHz) to the body surface and measuring the voltage differences between multiple locations. In medicine, EIT can be used to monitor the functional status of organs such as the lungs and heart, as well as to detect changes in the morphology and properties of muscle tissue. Generally speaking, the basic principles of EIT involve the following processes: 1) Current injection: The EIT system consists of an electrode ring placed around a body part. Current is injected into the body through one or more pairs of electrodes. This current is a safe, low-amplitude alternating current that is harmless to the human body. 2) Voltage measurement: As current passes through different tissues, different voltage drops are generated due to the varying electrical conductivities of these tissues (for example, muscle, fat, blood, and air). Additional electrodes are used to measure these voltage changes. 3) Data acquisition: During 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, known as boundary measurement data. 4) Image reconstruction: A mathematical model is used to convert boundary measurement data into an estimate of the internal conductivity distribution.

[0004] Electrical impedance tomography (EIT) systems typically include multiple electrodes attached to the body surface to be tested. These electrodes transmit test electrical signals to the surface, and imaging information is obtained via feedback electrodes. However, the distance between electrodes and the spacing between adjacent electrode strips in existing EIT systems can vary with body surface size. This causes the equivalent impedance paths between and between electrode strips to fluctuate repeatedly, resulting in blurred imaging information under the same excitation, making observation difficult. Therefore, improving the imaging quality of EIT systems has become a pressing technical challenge. Summary of the Invention

[0005] The present invention provides an electrical impedance imaging system, which can improve the imaging resolution and imaging clarity of the electrical impedance imaging system and improve the imaging quality.

[0006] The present invention provides an electrical impedance imaging system, comprising:

[0007] At least two electrode strips, two adjacent electrode strips being elastically connected; the electrode strips comprising a plurality of electrodes arranged in an array;

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

[0009] When each of the electrode belts is fixed to the surface of a body to be detected, the controller is configured to determine the excitation electrical signal provided to the electrode according to the inter-belt spacing between two adjacent electrode belts.

[0010] Optionally, the controller is specifically configured to:

[0011] Acquire a first mapping relationship between the distance and the electrical signal;

[0012] The excitation electrical signal is determined according to the inter-strip spacing and the first mapping relationship.

[0013] Optionally, the controller is specifically configured to:

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

[0015] Determining an inter-belt impedance value between two adjacent electrode belts according to the inter-belt spacing and the impedance value of the type;

[0016] The excitation electrical signal is determined according to the inter-band impedance value and the preset current.

[0017] Optionally, the controller is specifically configured to:

[0018] Calculating an average value of the inter-band impedance values, and using the average value as a reference impedance value;

[0019] The excitation electrical signal is determined according to 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 electrode belt is not fixed to the surface of the body to be detected, the electrode belt is a circular structure, and the diameter of the electrode belt is d1;

[0022] When the electrode belt is fixed to the surface of the body to be detected, the diameter of the electrode belt is d2, and the electrodes are arranged at equal intervals;

[0023] Among them, d2≥d1.

[0024] Optionally, the electrode belt further comprises a high-elastic fabric and a plurality of electrode wires;

[0025] The electrodes are fixed on the surface of the high-elasticity fabric at equal intervals, and the electrode wires are electrically connected to the electrodes and the controller respectively.

[0026] Optionally, two adjacent electrode belts are connected by using the high-elastic fabric.

[0027] Optionally, the electrode comprises silver chloride.

[0028] The technical solution provided by the present invention achieves three-dimensional electrical impedance imaging by providing at least two electrode strips, with adjacent electrode strips elastically connected; the electrode strips include multiple electrodes arranged in an array. A controller is also provided that is electrically connected to each electrode. When each electrode strip is fixed to the surface of a body to be examined, the controller is configured to determine an excitation signal to be provided to the electrode based on the inter-strip spacing between adjacent electrode strips. This excitation signal ensures that the current flowing between the electrode strips is a fixed value, allowing the feedback signal from the electrodes to accurately reflect image information beneath the surface of the body to be examined. This improves the imaging resolution and clarity of the electrical impedance imaging system, thereby enhancing imaging quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A schematic structural diagram of an electrical impedance tomography system provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0030] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It will be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all structures.

[0031] Figure 1 A schematic structural diagram of an electrical impedance imaging system provided by an embodiment of the present invention is shown in FIG. Figure 1 As shown, the electrical impedance imaging system 100 includes at least two electrode belts 10 and a controller 20: two adjacent electrode belts 10 are elastically connected; the electrode belt 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 an electrical signal to the electrode 11, or to receive a feedback electrical signal fed back by the electrode 11; when each electrode belt 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 electrode 11 based on the inter-belt spacing between the two adjacent electrode belts 10.

[0032] The electrode strips 10 are elastic and have strong elastic deformation capabilities. They can be applied to various body surfaces to be tested, such as the calf or arm. Applications can be tailored to specific needs and are not specifically limited here. The inter-strip spacing represents the distance between two adjacent electrode strips 10. This can be measured using a measuring tool such as a tape measure or vernier caliper and then manually entered into the controller 20. Alternatively, the inter-strip spacing can be obtained using methods such as 3D-printed bracket spacing, allowing the controller 20 to 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 the electrode strips 10 are placed on the surface of the body to be detected, the spacing h1 between the electrode strips 10 is fixed. After the electrode strips 10 are placed on the surface of the body to be detected, the spacing between two adjacent electrode strips 10 changes due to the different contours or sizes of the surface to be detected. Compared with the initial spacing, the changed spacing may become larger or smaller. The different spacings will 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 based on the current inter-strip spacing, so that after the excitation electrical signal is provided to the surface of the body to be detected through the electrode, the current flowing between the two electrode strips 10 is a fixed value. In addition, the feedback electrical signal fed back by the electrode 11 can be used to obtain image information about the area below the surface of the body to be detected, thereby improving imaging resolution and clarity.

[0034] It should be noted that Figure 1 The electrical impedance tomography system 100 is shown as including two elastically connected electrode belts 10, namely a first electrode belt 101 and a second electrode belt 102. In other optional embodiments, the electrical impedance tomography system 100 may also include three or more electrode belts 10, which can be arranged according to actual needs and are not specifically limited here.

[0035] It can be 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, and can also be other, which is not specifically limited here.

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

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

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

[0039] Specifically, when the first mapping relationship is a graph of spacing and electrical signals, after obtaining the current inter-strip spacing, the graph of spacing and electrical signals can be directly compared to determine the electrical signal on the graph corresponding to the current inter-strip spacing as the excitation electrical signal. Alternatively, when the first mapping relationship is a table of spacing and electrical signals, after obtaining the current inter-strip spacing, the table can be directly looked up to obtain the electrical signal corresponding to the current inter-strip spacing, and the electrical signal can be determined as the excitation electrical signal.

[0040] Optionally, the controller 20 is specifically configured to: obtain the type of the body 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 type includes muscle, bone, or fat, and the preset current can be a fixed value or a variable value, which can be set according to actual needs and is not specifically limited here. Optionally, determining the excitation electrical 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 electrical signal, and the excitation electrical signal can be obtained according to Ohm's law.

[0042] Specifically, the type of the body surface to be detected is different, and the corresponding impedance value is also different. The controller 20 stores the impedance value corresponding to each type, and uses the product of the impedance value and the inter-band spacing as the inter-band impedance value, and uses the product of the inter-band impedance value and the preset current as the required excitation electrical signal. The excitation electrical signal is a voltage signal, so that under the action of the excitation electrical signal, the current flowing between two adjacent electrode strips 10 is the preset current or close to the preset current, thereby making the feedback signal strength of the electrode 11 consistent or similar, avoiding the feedback signal of some electrodes 11 being too strong or too weak, and the current can pass through the body surface to be detected more evenly, reducing the boundary concentration effect, making the impact of internal impedance changes on voltage more significant, and improving imaging quality.

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

[0044] Optionally, the controller 20 is specifically configured to: calculate an average value of the impedance values ​​between the bands, and use the average value as a reference impedance value; and determine an excitation electrical signal according to the reference impedance value and a preset current.

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

[0046] Optionally, when the electrode belts 10 are not fixed to the surface of the body to be detected, the electrode belts 10 are circular in structure, and the diameter of the electrode belts 10 is d1; when the electrode belts 10 are fixed to the surface of the body to be detected, the diameter of the electrode belts 10 is d2, and the electrodes 11 are arranged at equal intervals; wherein, d2≥d1.

[0047] Specifically, when each electrode belt 10 is not fixed to the surface of the body to be detected, each electrode belt 10 is in a contracted state. When each electrode belt 10 is fixed to the surface of the body to be detected, part of the electrode belt 10 may be in a stretched state, while part of the electrode belt 10 may still be in a contracted state. The diameter d2 of the electrode belt 10 after being fixed to the surface of the body to be detected is greater than or equal to the diameter d1 when not fixed to the surface of the body to be detected. This allows the electrode belt 10 to be stably mounted on the surface of the body to be detected, increases the contact area between the electrodes 11 on the electrode belt 10 and the surface of the body to be detected, and improves the reliability of applying the excitation electrical signal and receiving the feedback signal.

[0048] Optionally, the electrode belt 10 further includes a high-elastic fabric and a plurality of electrode wires 12 ; the electrodes 11 are fixed on the surface of the high-elastic fabric at equal intervals, and the electrode wires 12 are electrically connected to the electrodes 11 and the controller 20 , respectively.

[0049] Among them, high-elastic fabrics include natural rubber, neoprene, silicone, spandex and other materials, which can be set according to actual needs.

[0050] Specifically, high-elastic fabrics have the characteristics of high elastic recovery rate, high fatigue resistance, and aging resistance. High-elastic fabrics usually use multi-layer composite materials. For example, the surface is covered with polytetrafluoroethylene film to improve wear resistance, the middle layer is embedded with aramid fibers to enhance tensile strength, and the inner layer is made of skin-friendly non-woven fabric to improve contact comfort. By setting the electrodes 11 on the surface of the high-elastic fabric, the spacing between the electrodes 11 is consistent before and after the high-elastic fabric is stretched, and there is no need to adjust the position of each electrode 11, thereby improving the convenience of use. Each electrode 11 is located on one side of the high-elastic fabric, and the electrode wire 12 is located on the other side of the high-elastic fabric. The electrode wire 12 can be fixedly electrically connected to the electrode 11 by soldering or other methods. The electrode wire 12 can be wound on the back of the electrode 11 and then contact the electrode 11, thereby increasing the contact area between the electrode wire 12 and the electrode 11 and improving the reliability of electrical signal transmission.

[0051] Optionally, two adjacent electrode belts 10 are connected by using high-elastic fabric.

[0052] Specifically, before being applied to different body surfaces to be tested, the spacing between the electrodes 11 on the electrode strips 10 is fixed. After being applied to different body surfaces to be tested, the high-elastic fabric between the electrode strips 10 has a certain degree of stretchability, so that the spacing between the electrode strips 10 and the high-elastic fabric between the electrode strips 10 will also experience a certain degree of stretching to adapt to different body surfaces to be tested, improving the user experience.

[0053] Optionally, the electrode 11 comprises silver chloride.

[0054] Among them, the probability of silver chloride generating polarization voltage under direct current or low-frequency alternating current is low, and the 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 impedance when the electrode 11 contacts the surface of the body to be detected, and improve the current injection efficiency. High contact impedance will cause signal attenuation. Silver chloride can stabilize the interface reaction, increase the current penetration depth, and improve the three-dimensional imaging resolution.

[0055] Note that the above are only preferred embodiments of the present invention and the technical principles employed. Those skilled in the art will appreciate that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments, combinations, and substitutions are possible for those skilled in the art without departing from the scope 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 scope of the present invention. The scope of the present invention is determined by the scope of the appended claims.

Claims

1. An electrical impedance tomography system, characterized in that: include: At least two electrode strips, two adjacent electrode strips being elastically connected; the electrode strips comprising a plurality of electrodes arranged in an array; a controller electrically connected to each of the electrodes; The controller is used to provide an electrical signal to the electrode, or receive a feedback electrical signal from the electrode; When each of the electrode belts is fixed to the surface of a body to be detected, the controller is configured to determine the excitation electrical signal provided to the electrode according to the inter-belt spacing between two adjacent electrode belts.

2. The electrical impedance tomography system according to claim 1, wherein: The controller is specifically configured to: Acquire a first mapping relationship between the distance and the electrical signal; The excitation electrical signal is determined according to the inter-strip spacing and the first mapping relationship.

3. The electrical impedance tomography system according to claim 1, wherein: The controller is specifically configured to: Obtaining the type of the body surface to be detected; Determining an inter-belt impedance value between two adjacent electrode belts according to the inter-belt spacing and the impedance value of the type; The excitation electrical signal is determined according to the inter-band impedance value and the preset current.

4. The electrical impedance tomography system according to claim 3, wherein: The controller is specifically configured to: Calculating an average value of the inter-band impedance values, and using the average value as a reference impedance value; The excitation electrical signal is determined according to the reference impedance value and the preset current.

5. The electrical impedance tomography system according to claim 3, wherein: The controller is specifically configured to use the product of the inter-band impedance value and the preset current as the excitation electrical signal.

6. The electrical impedance tomography system according to claim 1, wherein: When each of the electrode belts is not fixed to the surface of the body to be detected, the electrode belt is a circular structure, and the diameter of the electrode belt is d1; When the electrode belt is fixed to the surface of the body to be detected, the diameter of the electrode belt is d2, and the electrodes are arranged at equal intervals; Among them, d2≥d1.

7. The electrical impedance tomography system according to claim 1, wherein: The electrode belt also includes a high-elastic fabric and a plurality of electrode wires; The electrodes are fixed on the surface of the high-elasticity fabric at equal intervals, and the electrode wires are electrically connected to the electrodes and the controller respectively.

8. The electrical impedance tomography system according to claim 7, wherein: Two adjacent electrode belts are connected by using the high-elasticity fabric.

9. The electrical impedance tomography system according to claim 1, wherein: The electrodes include silver chloride.

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