Electrode ring for electrical impedance imaging and electrical impedance imaging system

Abstract

The application discloses an electrode ring and an electrical impedance imaging system for electrical impedance imaging. The electrode ring comprises a metal ring, a filler, an elastic fabric, a plurality of electrodes and a plurality of electrode lines, wherein the metal ring can adjust its diameter in a circular structure; the filler is arranged between the metal ring and the elastic fabric; the elastic fabric covers the metal ring, the filler and the plurality of electrodes; the plurality of electrode lines are wrapped between the filler and are led out as an electrode belt after being gathered together and are connected with an external electrical impedance imaging system; the plurality of electrodes are fixed on the surface of the elastic fabric in an equidistance manner, each electrode is connected by a corresponding electrode line, and the electrodes are not connected with each other. The electrode ring designed in the application can freely stretch and shrink in different limb diameter ranges, solves the problem of unfixed electrode spacing in the existing electrical impedance tomography electrode technology, and improves the wearing comfort and the stability of signal acquisition.

Description

Technical Field

[0001] This invention relates to the field of neuromuscular physiological detection technology, and more specifically, to an electrode ring and electrical impedance imaging system for electrical impedance imaging. 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 uses this information to create a tomographic 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] Besides its fundamental advantages such as low cost, portability, and no radiation, electrical impedance tomography (EIM) also boasts high temporal resolution, enabling continuous monitoring and capturing dynamic changes in muscle activity. This is invaluable for studying muscle responses and states under different exercise conditions. By monitoring real-time changes in muscle impedance, the temporal sequence and patterns of muscle activity can be analyzed in detail, revealing the dynamic characteristics of muscle contraction and relaxation.

[0004] Electrical impedance tomography (EIT) reconstructs images of the body's conductivity or electrical impedance distribution by applying a small alternating current (typically in the frequency range of 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 to detect changes in the morphology and properties of muscle tissue. In general, the basic principle of EIT involves the following process:

[0005] 1) Current Injection: The EIT system contains an electrode ring that wraps around a part of the body. Current is injected into the body through one or more selected pairs of electrodes. This current is a safe, low-amplitude alternating current that will not cause harm to the body.

[0006] 2) Voltage measurement: When current passes through different tissues, different voltage drops will be formed because different tissues have different electrical conductivities (such as the electrical conductivities of muscle, fat, blood and air are different). Other electrodes are used to measure these voltage changes.

[0007] 3) Data Acquisition: During a complete scan, current is injected through different electrode combinations, and the corresponding voltage response is recorded. This process generates a large number of voltage-current data points, known as boundary measurement data.

[0008] 4) Image reconstruction: Using a mathematical model, the boundary measurement data is converted into an estimate of the internal conductivity distribution. This step involves complex calculations because it requires solving the so-called "inverse problem".

[0009] The inverse problem refers to inferring the conductivity distribution (system characteristics) inside a body from a known voltage measurement result (output) and applied current pattern (input). This involves the following challenges: Non-uniqueness: Multiple different conductivity distributions may exist, producing the same surface voltage measurement result; Ill-conditioned nature: Even small measurement noise can lead to large fluctuations in the solution, i.e., the solution is unstable; Nonlinearity: The relationship between conductivity and voltage is nonlinear, increasing the complexity of the solution.

[0010] Since electrical impedance tomography (EIT) is essentially an inverse problem, the equidistant arrangement of electrodes is crucial for obtaining high-quality image reconstruction. This arrangement ensures uniform coverage of the entire measurement area, providing more comprehensive data acquisition. Inconsistent electrode spacing can lead to oversampling in some areas and undersampling in others, resulting in missing or distorted information during image reconstruction. Furthermore, equidistant electrode arrangement guarantees symmetry in data acquisition, which is essential for simplifying mathematical models and improving the stability of reconstruction algorithms. Symmetry helps reduce potential bias errors during reconstruction, resulting in more accurate images.

[0011] Furthermore, equidistantly distributed electrodes significantly reduce geometric uncertainty, which simplifies the inverse problem. Irregular electrode placement introduces additional geometric uncertainty, making reconstruction algorithms more difficult to handle and impacting image quality. Conversely, equidistantly distributed electrodes minimize this uncertainty, making reconstruction algorithms easier to process and thus improving image quality. This arrangement also helps improve the spatial resolution and contrast of the image. Since the distance between each electrode is fixed, the reconstruction algorithm can more accurately calculate changes in internal conductivity based on this fixed distance, generating higher-resolution images. Differences in conductivity between different tissues are fundamental to EIT imaging; equidistantly distributed electrodes can more accurately capture these differences, thereby improving contrast between different tissues and making details in the image more clearly visible. Equidistantly distributed electrodes also enhance system stability and reliability, reducing fluctuations caused by electrode placement uncertainty. This is particularly important for real-time monitoring applications, as it ensures high repeatability and reliability for each measurement. In clinical applications, reliability and accuracy are paramount; equidistantly distributed electrodes help ensure consistent results for each measurement, thereby improving diagnostic reliability. However, in actual measurement processes, electrodes usually need to be reattached after each measurement. This not only significantly increases measurement time but also makes it difficult to guarantee the standardization and consistency of electrode attachment each time, thus affecting the standardization and stability of measurement results.

[0012] In the prior art, the solutions provided in patent applications CN111012347A (An electrode strip, electrode structure, feed line, and electrical impedance imaging device) and CN116035554A (Electrode strip and electrode assembly for electrical impedance imaging) both employ elastic electrode strips. These electrode strips are highly elastic and adjustable, allowing for quick adaptation to limbs of different sizes without the need for repeated electrode re-attaching or complex adjustments. However, the material properties of the elastic strips and the irregular shapes of human limbs (such as thighs, calves, and arms) can easily lead to uneven pressure distribution, i.e., excessive pressure in some areas and insufficient pressure in others. This affects the contact quality between the electrode and the skin, resulting in unstable signal acquisition and impacting image quality.

[0013] Analysis reveals the following main shortcomings in existing technologies:

[0014] 1) The current electrode fixing design requires frequent re-attaching of electrodes or adjustment of the elastic band position during multiple measurements. This repetitive operation is not only time-consuming and labor-intensive, but also makes it difficult to ensure standardization and consistency for each measurement, easily leading to unreliable and poor repeatability of measurement results.

[0015] 2) When the elastic band is fixed, its deformation inevitably changes the distance between the electrodes, making it impossible to maintain an equidistant arrangement of the electrodes at all times. This change introduces additional geometric uncertainties, complicating the solution of the inverse problem and leading to a decrease in the quality of image reconstruction.

[0016] 3) Some solutions attempt to improve electrode fixation by incorporating additional design features, such as split structures or detachable components. However, these designs increase the complexity and manufacturing cost of the device, while potentially reducing the overall durability and ease of use of the system. Summary of the Invention

[0017] The purpose of this invention is to overcome the shortcomings of the prior art and provide an electrode ring and electrical impedance imaging system for electrical impedance imaging.

[0018] According to a first aspect of the present invention, an electrode ring for electrical impedance tomography is provided. The electrode ring includes a metal ring, a filler, an elastic fabric, a plurality of electrodes, and a plurality of electrode wires, wherein: the metal ring is adjustable in diameter while maintaining a circular structure; the filler is disposed between the metal ring and the elastic fabric; the elastic fabric covers the metal ring, the filler, and the plurality of electrodes; the plurality of electrode wires are wrapped around the filler and converge together to form an electrode strip for connection to an external electrical impedance tomography system; the plurality of electrodes are fixed at equal intervals on the surface of the elastic fabric, each electrode being connected by a corresponding electrode wire, and the electrodes are not connected to each other.

[0019] In one embodiment, the metal ring is formed by bending a metal strip, which is cylindrical or sheet-shaped.

[0020] In one embodiment, the metal strip is made of spring steel, stainless steel, copper alloy, titanium alloy, or nickel alloy.

[0021] In one embodiment, the filler is flexible polyurethane foam.

[0022] In one embodiment, the elastic fabric is selected from spandex, polyester elastic fiber, or a blend of nylon and elastic fiber.

[0023] In one embodiment, the plurality of electrodes are fixed metal spheres, or disposable electrodes or wet electrodes.

[0024] In one embodiment, the number of the plurality of electrodes is set to 16 or a multiple of 16.

[0025] In one embodiment, the elastic fabric is prepared using a weft knitting method.

[0026] According to a second aspect of the present invention, an electrical impedance imaging system is provided. The system includes:

[0027] Data acquisition unit: used to acquire voltage and current data of the target using the provided electrode ring for electrical impedance imaging;

[0028] Image reconstruction unit: used to obtain the corresponding conductivity distribution estimate based on the voltage and current data, and then obtain the impedance distribution image.

[0029] Compared with existing technologies, the advantages of this invention are that it provides an electrode ring, electrode band, and electrode assembly for electrical impedance tomography (EI) that is suitable for human bodies of different sizes and maintains an equidistant electrode distribution before and after changes in size. The provided electrode ring and electrode band offer high flexibility and adaptability, quickly adapting to limbs of different sizes without requiring repeated electrode re-attaching or complex adjustments. Whether the individual has a thicker or thinner thigh, the electrode assembly automatically adjusts to the optimal position, ensuring good contact between the electrodes and the skin, reducing measurement preparation time and improving the user experience. This invention can automatically adjust the electrode spacing, ensuring a good equidistant distribution of electrodes on limbs of different shapes and sizes. Furthermore, by using elastic materials or adjustable fasteners, the electrode ring or electrode band can automatically expand and contract according to the specific size of the limb, ensuring that the electrodes are always evenly distributed around the area to be measured, improving imaging accuracy and consistency.

[0030] Other features and advantages of the invention will become clear from the following detailed description of exemplary embodiments of the invention with reference to the accompanying drawings. Attached Figure Description

[0031] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of the invention and, together with their description, serve to explain the principles of the invention.

[0032] Figure 1 This is a schematic diagram of the overall structure of an electrode ring according to an embodiment of the present invention;

[0033] Figure 2 This is a line drawing of the overall structure of the electrode ring according to an embodiment of the present invention;

[0034] Figure 3 This is a schematic diagram of a metal ring according to an embodiment of the present invention;

[0035] Figure 4 This is a side view of an electrode ring structure according to an embodiment of the present invention;

[0036] Figure 5 This is a top view of an electrode ring structure according to an embodiment of the present invention;

[0037] Figure 6 This is a line drawing of an electrode ring according to an embodiment of the present invention;

[0038] Figure 7 A front view of an electrode ring structure according to an embodiment of the present invention;

[0039] Figure 8 This is a line drawing of an electrode ring according to an embodiment of the present invention;

[0040] Figure 9 This is a schematic diagram of the connection between electrodes and electrode wires according to an embodiment of the present invention. Detailed Implementation

[0041] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention.

[0042] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use.

[0043] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0044] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0045] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0046] Electrical impedance tomography (EIT) requires the placement of a certain number of electrodes around the area to be measured. These electrodes need to be equidistantly spaced, and a safe excitation current is applied alternately to two electrodes. The voltage difference between the remaining electrodes is then measured to obtain data for reconstructing the impedance image. For convenient biomedical EIT in practical applications, the electrodes should ideally be placed quickly and easily around the subject's body, minimizing the risk of electrode detachment and maintaining good contact with the body. Simultaneously, to obtain high-quality image data, the electrodes placed on the human body surface should ideally be evenly distributed around the area to be measured.

[0047] Current electrode placement methods are not suitable for human bodies of different sizes and typically require adjustments based on individual differences. When the measurement subject changes, electrodes often need to be reattached and repositioned, which is not only time-consuming but can also lead to inconsistent electrode distribution in each measurement, affecting data repeatability and accuracy. Furthermore, manually adjusting electrode positions is complex and time-consuming, causing significant inconvenience in practical applications. In addition, during EIT imaging, high-quality image data requires electrodes to be evenly distributed around the area to be measured. However, existing electrode placement methods struggle to ensure equidistant electrode spacing, especially on curved structures such as limbs. Manually attaching electrodes is not only cumbersome but also makes it difficult to guarantee the accuracy and consistency of each attachment. While fixing electrodes to a strip of fabric simplifies the installation process, it still presents problems such as poor contact between the electrodes and biological tissue and the inability to guarantee equidistant electrode spacing.

[0048] To overcome the shortcomings of existing technologies, this invention designs a novel electrode ring (or electrode ring device), which generally includes an adjustable-radius metal ring, filler, elastic fabric, electrodes, and electrode wires. Specifically, in conjunction with... Figure 1 and Figure 2 As shown, the provided electrode ring, from the inside out, comprises a metal ring, elastic filler between the elastic fabric and the metal ring, elastic fabric wrapping around various components, and a set of electrodes evenly distributed on the elastic fabric. Each electrode is connected by an electrode wire (the electrodes are not connected to each other; each electrode is connected by one electrode wire, but multiple wires converge together). The electrode wires are wrapped between the filler, and after converging together, an electrode strip is led out to connect with other parts of the electrical impedance imaging system.

[0049] 1) Metal ring

[0050] The metal ring plays a crucial role in the entire electrode ring system in two main ways. First, due to its high elastic modulus, the metal ring's radius changes while its shape remains nearly constant during stretching, thus shaping the elastic fabric surrounding it and ensuring that the fabric also maintains a stable circular shape except for the radius change. Second, after the shape changes, the metal ring provides an inward stress caused by an elastic restoring force. Due to the metal ring's high elasticity, this force is much greater than that of common elastic bands or 3D printed materials, significantly improving the stability of the electrode's contact with the limb. This metal ring has an adaptive radius adjustment function, capable of changing its radius to adapt to different limb sizes while maintaining shape stability and a circular structure, providing stable support for external components both during and after adjustment. The metal ring can be made of high elastic modulus materials (such as spring steel and stainless steel) to ensure sufficient restoring force after deformation.

[0051] like Figure 3As shown, the metal ring can be formed by bending a strip of metal, which can be cylindrical or sheet-shaped, and made of a material with a high elastic modulus, such as spring steel, stainless steel, copper alloy, titanium alloy, or nickel alloy. These materials have characteristics such as high elastic modulus, good elastic limit, low hysteresis (small energy loss during cyclic deformation), and fatigue resistance. Through this design, the metal ring can ensure the stability and shape consistency of the electrode ring. For example, maintaining the circular structure of the electrode ring can provide stable support even under different limb shapes, and provide uniform inward pressure, ensuring sufficient contact between the electrode and the skin surface and reducing poor contact problems caused by differences in limb shape.

[0052] 2) Filler

[0053] In designing the electrode ring, to improve wearing comfort and electrode contact stability, a filling material is added between the metal ring and the elastic fabric to enhance wearing comfort and evenly distribute pressure within the ring. Preferably, this filling material is soft polyurethane foam, as it possesses advantages such as low density, good elastic recovery, excellent breathability, and thermal insulation. By incorporating this filling material, pressure unevenness caused by differences in limb shape can be balanced, ensuring consistent contact between the electrodes and the skin, providing soft support, reducing wearer discomfort, and further stabilizing the electrode wire position, preventing signal interference caused by movement or deformation.

[0054] Because the human limb is not a perfect cylinder, the pressure exerted by the circular metal ring on the limb is unevenly distributed, causing some protruding parts of the limb to bear greater pressure, while parts with smaller radii experience relatively less pressure. This uneven pressure distribution can affect the effective contact between the electrode and the skin. By using elastic filler, appropriate elastic support can be provided for different limb shapes, ensuring that the electrode can conform to the skin surface with appropriate pressure, thereby improving electrode stability and wearing comfort. Therefore, the filler not only enhances the wearing experience but also plays an important role in evenly distributing force and increasing electrode stability.

[0055] In summary, by adding soft polyurethane foam as a filler between the metal ring and the elastic fabric, good adaptability to different limb shapes is achieved, ensuring uniform pressure between the electrode and the skin, improving wearing comfort and electrode stability, and enhancing the contact effect between the electrode and the human body surface. By adding a filler material with specific physical properties (such as low density and good elastic recovery) to the inner layer of the electrode ring, uniform pressure distribution can be maintained even on non-ideal cylindrical body parts.

[0056] 3) Elastic fabric

[0057] Combination Figure 4 , Figure 5 , Figure 6 , Figure 7 and Figure 8 As shown, elastic fabric is used to wrap the metal ring, filler, and wires connecting the electrodes, ensuring the electrodes are securely fixed within the rings formed inside. This fabric stretches uniformly upon deformation and possesses excellent elastic recovery, maintaining shape stability. To achieve this performance, the fabric can be made from spandex, polyester elastic fibers (such as T400 or Lycra T400), or blends of nylon and elastic fibers. Weft knitting is used to further enhance its properties, as this method produces fabrics with excellent multidirectional stretch and superior tensile recovery, ensuring the fabric retains its original shape after deformation.

[0058] When the size of the metal ring is adjusted, the change in its radius causes the elastic fabric wrapped around it to change size accordingly. Because the metal ring maintains its shape after the radius change, the elastic fabric also maintains its shape after the size change. Thanks to the uniform deformation characteristics of the elastic fabric, the electrodes fixed within the ring and evenly distributed can maintain equal distances between each other even after the radius of the entire ring changes.

[0059] Elastic fabric covers the metal ring, filler, and electrode wires. It is made of highly elastic, fatigue-resistant materials (such as spandex, blended fabrics, and polyester elastic fibers) and enhanced by weft knitting to improve its deformation stability. Using a specific type of elastic fabric to wrap the entire device ensures that the overall structure can adapt to different limb shapes while maintaining good tensile recovery performance, further enhancing the wearer's comfort. For example, when the diameter of the metal ring changes, the elastic fabric maintains its shape stability and ensures equidistant distribution of the electrodes. Furthermore, the elastic fabric provides support and protection, preventing the filler or electrode wires from detaching, while also enhancing the overall durability and flexibility of the structure.

[0060] 4) Electrodes and electrode wires

[0061] See Figure 9 As shown, electrodes are fixed to the surface of elastic fabric and located within a loop. Each electrode is connected by an electrode wire, which is wrapped inside the elastic fabric. Filler stabilizes the electrode wires, and multiple electrode wires converge and exit the electrode loop from the same opening. The other end of the electrode wires is connected to other parts of the electrical impedance imaging system. The electrodes can apply different currents at specific frequencies to measure electrical information and electrophysiological signals on the human body surface. The electrodes can be fixed metal spheres, disposable electrodes, or wet electrodes, and can be used for electrocardiogram (ECG) or electromyography (EMG) measurements.

[0062] In one embodiment, the electrode assembly for electrical impedance tomography typically comprises 16 or a multiple thereof, all evenly spaced on a circular ring, regardless of the exact number. This design ensures that the electrodes fixed to the ring remain evenly spaced on a circle, regardless of the ring's size, guaranteeing the accuracy of data acquisition during electrical impedance tomography.

[0063] In summary, the electrodes are fixed to the surface of the elastic fabric at equal intervals. The internally connected electrode wires are wrapped between the filler material and converge at the output port of the electrode ring, connecting to the external electrical impedance imaging system. By applying currents of different frequencies, the electrodes acquire high-quality electrical impedance signals, adapting to various measurement needs. The stable arrangement and convergence design of the electrode wires ensures high efficiency and anti-interference capability in signal transmission, while simplifying the connection and use of the equipment.

[0064] Furthermore, based on the electrode ring of the above embodiments, the present invention also provides an electrical impedance imaging system. For example, the system includes: a data acquisition unit that acquires voltage-current data of a target using the electrode ring provided by the present invention; and an image reconstruction unit that, based on the voltage-current data, obtains a corresponding conductivity distribution estimate, and then obtains an electrical impedance distribution image. The data acquisition unit and the image reconstruction unit can be implemented in software, hardware, or a combination of both.

[0065] In summary, compared with the prior art, the present invention has the following advantages:

[0066] 1) While existing elastic band designs offer good adaptability and adjustability, the material properties and irregular shapes of human body parts cause the distance between electrodes to change during adjustment, affecting the quality of image reconstruction. This invention, through innovative design and structure (such as a combination of metal rings, fillers, and elastic fabric), ensures that the electrodes maintain an equidistant arrangement regardless of size adjustments, solving the problem of electrode spacing variation and improving the stability and accuracy of inverse problem solving.

[0067] 2) Existing elastic bands, due to material properties and the irregular shape of the human body, result in uneven pressure distribution during fixation. Some areas may bear greater pressure while others receive insufficient pressure, affecting the stability of signal acquisition. This invention utilizes soft polyurethane foam as a filler, providing appropriate elastic support under different limb shapes, ensuring that the electrodes can adhere to the skin surface with appropriate pressure, thus improving wearing comfort and signal acquisition stability.

[0068] 3) Although existing elastic bands can adapt to limbs of different thicknesses to some extent, they still have limitations when faced with complex changes in the curvature of the human body, making it difficult to guarantee the standardization and consistency of each measurement. This invention uses a metal ring material with a high elastic modulus, which allows the electrode ring to flexibly adapt to limbs of different diameters and maintain a circular structure after size adjustment, ensuring good contact quality between the electrode and the skin.

[0069] 4) In existing technologies, each measurement requires re-attaching electrodes or making complex adjustments, increasing measurement time and difficulty, and reducing user experience. The electrode ring provided by this invention is highly flexible and adaptable, and can quickly adapt to limbs of different sizes. It eliminates the need to re-attach electrodes or make complex adjustments each time; each time it is worn, it only requires stretching and expanding the electrode ring, simplifying the measurement preparation process and improving the user's ease of operation and experience.

[0070] 5) This invention adopts a design that combines a metal ring with a high elastic modulus and elastic fabric, which improves the durability of the device while ensuring its flexibility, providing users with a better wearing experience, and is suitable for long-term measurement scenarios.

[0071] This invention can be a system, method, and / or computer program product. A computer program product may include a computer-readable storage medium having computer-readable program instructions loaded thereon for causing a processor to implement various aspects of the invention.

[0072] Computer-readable storage media can be tangible devices capable of holding and storing instructions for use by an instruction execution device. Computer-readable storage media can be, for example, but not limited to, electrical storage devices, magnetic storage devices, optical storage devices, electromagnetic storage devices, semiconductor storage devices, or any suitable combination thereof. More specific examples (a non-exhaustive list) of computer-readable storage media include: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), static random access memory (SRAM), portable compact disc read-only memory (CD-ROM), digital multifunction disc (DVD), memory sticks, floppy disks, mechanical encoding devices, such as punch cards or recessed protrusions storing instructions thereon, and any suitable combination thereof. The computer-readable storage media used herein are not to be construed as transient signals themselves, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through waveguides or other transmission media (e.g., light pulses through fiber optic cables), or electrical signals transmitted through wires.

[0073] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of an instruction containing one or more executable instructions for implementing a specified logical function. In some alternative implementations, the functions marked in the blocks may occur in a different order than those marked in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions. It will be known to those skilled in the art that implementation in hardware, implementation in software, and implementation using a combination of software and hardware are equivalent.

[0074] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, and are not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein. The scope of the invention is defined by the appended claims.

Claims

1. An electrode ring for electrical impedance imaging, comprising a metal ring, a filler, an elastic fabric, a plurality of electrodes, and a plurality of electrode wires, wherein: The diameter of the metal ring can be adjusted when it has a circular structure; The filler is disposed between the metal ring and the elastic fabric; the elastic fabric covers the metal ring, the filler, and the plurality of electrodes; the plurality of electrode wires are wrapped between the filler and converge together to form an electrode strip, which is then connected to an external electrical impedance imaging system; the plurality of electrodes are fixed at equal intervals on the surface of the elastic fabric, each electrode is connected by a corresponding electrode wire, and the electrodes are not connected to each other. The metal ring is formed by bending a metal strip, which can be cylindrical or sheet-shaped. The metal ring is made of a high elastic modulus material. During the stretching process of the electrode ring, the radius of the metal ring changes but the shape remains constant, and the metal ring provides inward stress caused by elastic restoring force.

2. The electrode ring for electrical impedance imaging according to claim 1, characterized in that, The metal strip is made of spring steel, stainless steel, copper alloy, titanium alloy, or nickel alloy.

3. The electrode ring for electrical impedance imaging according to claim 1, characterized in that, The filler is flexible polyurethane foam.

4. The electrode ring for electrical impedance imaging according to claim 1, characterized in that, The elastic fabric is made of spandex, polyester elastic fiber, or a blend of nylon and elastic fiber.

5. The electrode ring for electrical impedance imaging according to claim 1, characterized in that, The plurality of electrodes are fixed metal spheres.

6. The electrode ring for electrical impedance imaging according to claim 1, characterized in that, The number of the plurality of electrodes is set to 16 or a multiple of 16.

7. The electrode ring for electrical impedance imaging according to claim 1, characterized in that, The elastic fabric is prepared by weft knitting.

8. The electrode ring for electrical impedance imaging according to claim 1, characterized in that, The multiple electrodes are either disposable electrodes or wet electrodes.

9. An electrical impedance imaging system, comprising: Data acquisition unit: used to acquire voltage and current data of the target using the electrode ring for electrical impedance imaging as described in any one of claims 1 to 8; Image reconstruction unit: used to obtain the corresponding conductivity distribution estimate based on the voltage and current data, and then obtain the impedance distribution image.

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