Magnetic resonance apparatus, superconducting shim coil and method of manufacturing thereof

Abstract

The application relates to a magnetic resonance device, a superconducting shimming coil and a manufacturing method thereof. The superconducting shimming coil comprises a winding drum, the winding drum is provided with a saddle-shaped winding groove group, the winding groove group comprises a plurality of layer-by-layer sleeved winding grooves, and each winding groove is in a closed shape; and a superconducting wire is arranged in the winding groove. By fixing the superconducting wire in the winding groove of the winding drum, the winding process of the superconducting wire is simplified, the manufacturing of the superconducting shimming coil can be directly realized by fixing the superconducting wire in the winding groove, the superconducting wire does not need to be bent during winding and can be directly placed in the winding groove, the operation is convenient, the manufacturing of the superconducting shimming coil is facilitated, meanwhile, the superconducting wire can generate a uniform main magnetic field during work, the service performance of the magnetic resonance device is guaranteed, and the accuracy of an imaging result is further guaranteed.

Description

Technical Field

[0001] This invention relates to the field of medical imaging equipment technology, and in particular to a magnetic resonance imaging device, a superconducting shimming coil, and a method for manufacturing the same. Background Technology

[0002] The magnetic field strength and uniformity of the superconducting main magnet are important indicators for evaluating its performance, thereby ensuring the performance of the magnetic resonance imaging (MRI) device. The magnetic field strength and uniformity of the superconducting main magnet are related to the winding method of the superconducting wire on the winding drum. Typically, when winding the superconducting main magnet, the superconducting wire is first adhered to a planar carrier, and then laid on the winding drum.

[0003] When using this winding method, the superconducting wire must first be fixed onto a planar carrier according to a predetermined trajectory using tooling or other positioning components. Then, the planar carrier is fixed onto the winding drum. Moreover, after the superconducting wire is fixed onto the carrier, it needs to be bent into a predetermined trajectory before it can be fixed onto the carrier. This method of winding superconducting wire is cumbersome and inconvenient for coil winding. Summary of the Invention

[0004] Therefore, it is necessary to address the current problem of cumbersome coil winding by providing a magnetic resonance device, a superconducting shimming coil, and its manufacturing method that are easier to wind.

[0005] A superconducting shimming coil, comprising:

[0006] A winding drum having a saddle-shaped winding groove group, the winding groove group comprising multiple nested winding grooves, each winding groove being closed.

[0007] The superconducting wire is disposed in the winding groove.

[0008] In one embodiment, each of the winding slots has a wire outlet that communicates with the outer winding slot.

[0009] Not less than one of the superconducting wires is wound in each winding slot.

[0010] In one embodiment, the winding drum has multiple sets of winding grooves, which are regularly arranged on the winding drum.

[0011] In one embodiment, the superconducting shimming coil further includes an insulating component laid on the inner wall of the winding groove.

[0012] In one embodiment, the superconducting shimming coil further includes a binding portion, which is sleeved on the outside of the winding drum to fix the superconducting wire in the winding groove.

[0013] A method for fabricating a superconducting shimming coil includes the following steps:

[0014] The distribution of the winding slots on the winding drum is calculated based on the distribution of the main magnetic field.

[0015] The winding grooves are processed on the winding drum according to the distribution of the winding grooves;

[0016] One or more superconducting wires are wound into a wire bundle and installed in the winding groove.

[0017] In one embodiment, the step of calculating the distribution of the winding slots based on the distribution of the main magnetic field includes:

[0018] The distribution of the current density in the winding drum is calculated based on the distribution of the main magnetic field.

[0019] The current density is discretized to obtain the wire harness trajectory distribution.

[0020] The distribution of the winding slots is determined based on the distribution of the wire harness trajectory.

[0021] In one embodiment, the step of machining the winding groove assembly on the winding bobbin includes:

[0022] A cylinder is provided, and the surface of the cylinder is finished.

[0023] The winding grooves are formed by etching on the surface of the cylinder.

[0024] In one embodiment, the winding groove group includes multiple winding grooves, which are nested one inside the other; the step of installing the wire bundle made of multiple superconducting wires into the winding grooves includes:

[0025] The wire harness is segmented and shaped;

[0026] The segmented and shaped wire harness is inserted into the winding groove, and a fixing device is used to fix the segmented and shaped wire harness in the winding groove.

[0027] A magnetic resonance imaging device includes a cryostat and a superconducting shimming coil, wherein the superconducting shimming coil is installed in the cryostat.

[0028] The superconducting shimming coil includes:

[0029] A winding drum having a saddle-shaped winding groove group, the winding groove group comprising multiple nested winding grooves, each winding groove being closed.

[0030] The superconducting wire is disposed in the winding groove.

[0031] By adopting the above technical solution, the present invention has at least the following technical effects:

[0032] The present invention relates to a magnetic resonance imaging (MRI) device, a superconducting shimming coil, and a method for manufacturing the same. A saddle-shaped winding groove assembly is provided on the winding drum, with multiple nested winding grooves, each used to mount a superconducting wire. By fixing the superconducting wire in the winding grooves of the winding drum, the cumbersome process of current superconducting wire winding is effectively solved, simplifying the winding process. The superconducting wire can be directly fixed in the winding groove to achieve the fabrication of the superconducting shimming coil. Moreover, the superconducting wire does not need to be bent during winding; it can be directly placed in the winding groove, making operation convenient and facilitating the fabrication of the superconducting shimming coil. Simultaneously, it ensures that the superconducting wire generates a uniform main magnetic field during operation, guaranteeing the performance of the MRI device and thus ensuring the accuracy of the imaging results. Attached Figure Description

[0033] Figure 1A This is a schematic diagram of a magnetic resonance system structure according to an embodiment of this application;

[0034] Figure 1B This is a cross-sectional view of a superconducting shimming coil according to an embodiment of this application;

[0035] Figure 2 for Figure 1B A three-dimensional view of the winding drum in the superconducting shimming coil shown;

[0036] Figure 3 To and Figure 2 The superconducting wire corresponding to the winding drum in the middle;

[0037] Figure 4 for Figure 2 The plan view of the winding slot assembly shown;

[0038] Figure 5 for Figure 1B A magnified view of a portion of the winding slot in the superconducting shimming coil shown;

[0039] Figure 6 This is a current density distribution diagram of a magnetic resonance imaging (MRI) device.

[0040] Figure 7 for Figure 2 A schematic diagram showing the direction of current in a superconducting shimming coil;

[0041] Figure 8 This is a schematic diagram of a winding bracket according to an embodiment of this application.

[0042] in:

[0043] C. Magnetic Resonance Equipment; 100. Superconducting Shimming Coil; 110. Winding Spool; 111. Winding Slot Assembly; 1111. Winding Slot; 1112. Outlet; 120. Superconducting Conductor; 130. Insulating Components; 140. Binding Part; 200. Superconducting Magnet; 210. Cryogenic Holder; 211. Refrigeration Unit; 212. Outer Container; 213. Intermediate Shielding Layer; 214. Inner Container; 220. Main Magnet; 221. Main Coil Frame; 222. Main Coil; 223. Shielded Coil Frame; 224. Shielded Coil; 300. Gradient Coil; 400. Fixing Assembly. Detailed Implementation

[0044] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0045] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0046] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0047] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0048] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0049] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0050] To address the problem of reduced detection space caused by the placement of shimming coils in existing technologies, this application proposes a superconducting magnet assembly, which may include a cryogenic holder, a main magnet, and shimming coils. The cryogenic holder can surround and form the detection space, allowing the object to be detected to enter. The cryogenic container simultaneously has a space to accommodate the main magnet and the shimming coils, and this space is isolated from the detection space by the cryogenic holder's shell. The space within the cryogenic holder can contain a cryogenic cooling medium for cooling the main magnet, shimming coils, etc., disposed within the cryogenic holder. The main magnet may include a main coil and a main coil frame for supporting the main coil, and the main magnet is used to generate the main magnetic field. The shimming coils include multiple saddle-shaped coils, each formed by a conductor following a predetermined trajectory, capable of simultaneously shimming the main magnetic field generated by the main magnet with first-order, second-order, and higher-order shimming, improving the uniformity of the main magnetic field in the imaging region. The saddle-shaped coils are disposed within the shimming space and can be positioned adjacent to the main magnet, such as on the outside or inside of the main magnet. In one embodiment, the saddle-shaped coil is positioned outside the main magnet rather than within the detection aperture formed by the main magnet / low-temperature holder, thereby avoiding the problem of a significant reduction in the detection aperture caused by the placement of the shimming coil.

[0051] The saddle-shaped coils included in the shimming coil can be formed from conductors such as copper and aluminum, or from superconducting wires made of superconducting materials. For example, the superconducting material forming the superconducting wire can be one or more combinations of niobium, thallium, copper-oxide superconductors, iron-based superconductors, magnesium boride superconductors, lanthanum, strontium, etc. See also Figures 1A to 5 One embodiment of this application provides a superconducting shimming coil 100 composed of superconducting wires, which is applied in a corresponding magnetic resonance imaging (MRI) device C. This superconducting shimming coil 100 is used in the MRI device to generate a uniform magnetic field to image the location of the patient's lesion, ensuring accurate imaging results. It is understood that the uniformity of the magnetic field of the superconducting shimming coil 100 affects the performance of the MRI device, and consequently, the accuracy of the imaging results.

[0052] Considering that laying and pasting the superconducting wire of the superconducting shimming coil onto a planar carrier and then fixing it to a winding drum is a rather cumbersome process, this application provides a novel superconducting shimming coil 100. This superconducting shimming coil 100 can ensure the uniformity of the generated magnetic field, improve the performance of magnetic resonance imaging equipment, and simplify the manufacturing process, making it easier to form. The specific structure of the superconducting shimming coil 100 is described in detail below.

[0053] The magnetic resonance imaging (MRI) device C may include a superconducting magnet 200, a gradient coil 300, a radio frequency coil, etc. See also... Figure 1AThe superconducting magnet 200 includes a cryogenic holder 210 and a main magnet 220 disposed inside the cryogenic holder. The cryogenic holder 210 has an axial through hole along its axial direction to form an annular cavity within the cryogenic holder 210. The axial through hole is used to accommodate the gradient coil 300, and the annular cavity is used to accommodate the main magnet 220, so that the cryogenic holder 210, the gradient coil 300, and the main magnet 220 are coaxially assembled and fixed to form an integral structure.

[0054] The main magnet 220 includes a main coil 222 and a main coil frame 221 for supporting the main coil 222. To achieve superconductivity in the main magnet 220, a cryostat 211 is also provided on the cryostat 210. The cryostat 211 has a very low-temperature cooling electrode (also called a cold head). The cryostat 210 can contain a cooling medium. The cooling electrode of the cryostat 211 exchanges heat with the cooling medium through heat transfer to the cryostat 210, thereby indirectly cooling the main magnet 220. The cryogenic medium is liquid helium. Alternatively, a heat conduction element can be provided between the cryostat 210 and the cooling electrode of the cryostat 211 to achieve heat exchange between the two.

[0055] The cryogenic holder 210 has a multi-layered container structure, including an outer container 212, an inner container 214, and an intermediate shielding layer 213. The outer container is made of steel, preferably carbon steel or stainless steel. The outer container 212 includes a first outer cylinder and a first inner cylinder arranged radially from the center outwards. Both the first outer cylinder and the first inner cylinder are hollow cylindrical structures. The space enclosed by the inner side of the first inner cylinder is a detection space. End caps are provided at both ends of the first outer cylinder, and the end caps are connected to the first inner cylinder and the first outer cylinder respectively to seal them. With this arrangement, the internal space of the first inner cylinder of the outer container forms the aforementioned axial through hole, and an annular cavity is formed between the first inner cylinder, the first outer cylinder, and the first end cap.

[0056] Furthermore, an inner container 214 is provided inside the annular cavity. The inner container includes a second inner cylinder and a second outer cylinder arranged radially from the center inward. Both the second inner cylinder and the second outer cylinder are hollow cylindrical structures. Second end caps are provided at both ends of the second inner cylinder. The second end caps are annular structures and are connected to the second inner cylinder and the second outer cylinder respectively to seal them.

[0057] An intermediate shielding layer 213 is provided between the outer container and the inner container. The intermediate shielding layer includes a third inner cylinder and a third outer cylinder arranged radially from the center inward. Both the third inner cylinder and the third outer cylinder are hollow cylindrical structures. A third end cap is provided at both ends of the third inner cylinder. The third end cap is an annular structure and is connected to the third inner cylinder and the third outer cylinder respectively to seal them.

[0058] Furthermore, the internal space of the inner container 214, which is the receiving space, is provided with a main magnet 220. The main magnet 220 includes a main coil 222 and a main coil frame 221 for fixing the main coil 222. It can be understood that the main coil frame 221 has coil slots for receiving and fixing the main coil 222.

[0059] The superconducting magnet assembly also includes a shielding coil and a shielding coil frame for supporting the shielding coil, wherein the shielding coil frame is located outside the main coil frame.

[0060] In this embodiment, the shielding coil 224 is fixed and supported on the shielding coil frame 223. Both the shielding coil frame 223 and the main coil frame 221 are annular structures, and the axes of the shielding coil frame 223, the main coil frame 221, and the inner container 214 coincide. Optionally, the radial dimension of the shielding coil frame 223 is larger than the radial dimension of the main coil frame 221, that is, the shielding coil frame 223 is located outside the main coil frame 221.

[0061] One or more winding supports may be provided between the main coil frame 221 and the shielding coil frame 223. Winding slots may be formed on the winding supports, and one or more saddle-shaped coils may be disposed in the winding slots. The winding supports may be configured as winding cylinders sleeved around the outside of the main coil 222, with multiple saddle-shaped coils disposed on the winding cylinders. Alternatively, the winding supports may be non-cylindrical structures. In other embodiments, the winding supports may include two semi-cylinders, one at the top and one at the bottom of the main coil 222, which may cooperate to surround the outside of the main coil 222.

[0062] In one embodiment, a superconducting shimming coil 100 is disposed in the space between the main coil frame 221 and the shielding coil frame 223. This superconducting shimming coil 100 is used to generate an auxiliary magnetic field. The superconducting shimming coil 100 may include a first superconducting shimming coil and a second superconducting shimming coil. The first superconducting shimming coil is disposed adjacent to the main coil, and the second superconducting shimming coil is disposed outside the first superconducting shimming coil. The density of the main coil contained in the first superconducting shimming coil is greater than the density of the main coil contained in the second superconducting shimming coil.

[0063] It is understood that the embodiments of this application only provide illustrative examples of the arrangement and structure of the superconducting shimming coils. The number and type of superconducting shimming coils 100 are not specifically limited, but are determined based on the distribution of the main magnetic field. For example, the superconducting shimming coils 100 can be configured as a first saddle-shaped superconducting shimming coil, a second saddle-shaped superconducting shimming coil, and a third saddle-shaped shimming coil, arranged sequentially around the inner frame from the inside out. Alternatively, the superconducting shimming coils 100 can be configured as a solenoid shimming coil, a first saddle-shaped superconducting shimming coil, a second saddle-shaped superconducting shimming coil, and a third saddle-shaped shimming coil, arranged sequentially from the inside out. Different superconducting shimming coils can be respectively arranged on the same support structure or on different support structures. In one embodiment, the first saddle-shaped superconducting shimming coil and the second saddle-shaped superconducting shimming coil can be simultaneously arranged on one support structure (winding cylinder 110). For example, a first saddle-shaped superconducting shimming coil is set on the inner side of the winding drum 110, and a second saddle-shaped superconducting shimming coil is set on the outer side of the winding drum 110. During the assembly process of the magnetic resonance device C, the assembly is completed in one go, improving the installation efficiency.

[0064] See Figures 1B to 4 In one embodiment, the superconducting shimming coil 100 includes a winding drum 110 and a superconducting wire 120. The winding drum 110 has a saddle-shaped winding groove group 111, which includes a plurality of nested winding grooves 1111, each winding groove 1111 being closed. The superconducting wire 120 is disposed in the winding groove 1111.

[0065] The winding drum 110 serves as the supporting body for the superconducting shimming coil 100, supporting the superconducting wire 120 to ensure that an auxiliary magnetic field is generated around the winding drum 110 during operation, thus guaranteeing performance. The winding drum 110 is a hollow cylindrical shape, with its hollow portion corresponding to the magnet aperture of the magnetic resonance imaging (MRI) device. The superconducting wire 120 is wound around the outside of the winding drum 110. When energized, the superconducting wire 120 generates an auxiliary magnetic field, which, together with the main magnetic field formed by the superconducting magnet, creates a uniform magnetic field distribution.

[0066] Specifically, the winding drum 110 is provided with a winding groove assembly 111, which is used to lay the superconducting wire 120. Understandably, a groove is formed on the outer circumferential surface of the winding drum 110; this groove is the winding groove assembly 111. The superconducting wire 120 is located within the winding groove assembly 111. This prevents the superconducting wire 120 from being exposed, ensuring its performance and preventing it from detaching from the winding drum 110, thus guaranteeing its usability.

[0067] The winding groove assembly 111 includes multiple winding grooves 1111, which are nested in layers (diffused outwards from the center). Each winding groove 1111 contains a superconducting wire 120. Furthermore, there is a spacing between adjacent winding grooves 1111 to prevent interference between adjacent superconducting wires 120. The winding grooves 1111 can be arranged in a closed configuration. This ensures that when the superconducting wire 120 is energized, a magnetic field can be generated around its periphery, guaranteeing the uniformity of the magnetic field. Exemplarily, in this embodiment, the number of winding grooves 1111 is five. Of course, in other embodiments of this application, the number of winding grooves 1111 can also be two, three, or even more, etc.

[0068] In other embodiments, two adjacent winding slots are connected, and a wire bundle made of multiple superconducting wires can be wound around the central winding slot in sequence, and enter the next winding slot through the connecting space of the adjacent winding slots. In this way, the wire bundle is fixed along the trajectory of the winding slots to form a saddle-shaped coil.

[0069] Furthermore, the winding slot group 111 is saddle-shaped, and the wiring trajectory of the winding slot group 111 is calculated using a Harmonic expression:

[0070] in, The main magnetic field, and This is a first-order term, corresponding to the shimming component of the saddle-shaped shimming coil; The shimming component corresponding to the solenoid shimming coil; and These are second-order terms, corresponding to the shimming components of the saddle-shaped shimming coil.

[0071] Current superconducting shims are mainly A simple toroidal coil can affect the uniformity of the magnetic field. Therefore, the layout shape of the winding slot group 111 in the superconducting shimming coil 100 of this application is calculated using the Harmonic expression. The components of the saddle-shaped shim coil are eliminated. etc. Among them, and These represent two first-order terms in a harmonic function, and similarly, and and These represent the four second-order terms in the harmonic function. and These represent the six third-order terms in the harmonic function. This pattern continues, but the higher the order, the smaller the impact on the main magnetic field, and the higher the cost. Therefore, the main magnetic field corresponds to the 0th-order term in the harmonic function; all other orders affect the uniformity of the main magnetic field and need to be eliminated as much as possible. Based on this, shimming coils for first-order and higher-order harmonic function terms were fabricated to eliminate these terms. In this embodiment, the superconducting shimming coils corresponding to the lower-order terms of the harmonic function are placed close to the main coil, while the superconducting shimming coils corresponding to the higher-order terms of the harmonic function are placed further away from the main coil. For more details, please refer to [link to documentation]. Figure 1A The first-order term in the harmonic function corresponding to the first superconducting shim coil or The second superconducting shimming coil corresponds to the second-order term in the harmonic function. and and One or more of the first superconducting shimming coils and the second superconducting shimming coils are mounted on different winding cylinders 110. In this way, the wiring trajectory of the winding slot group 111 is saddle-shaped, so that the shape of each winding slot 1111 is a closed structure with asymmetrical circumference, thereby improving the magnetic field uniformity of the superconducting shimming coil 100.

[0072] The superconducting shimming coil 100 of this application effectively solves the problem of the cumbersome superconducting wire winding process by fixing the superconducting wire 120 in the winding groove 1111 of the winding cylinder 110. It simplifies the winding process of the superconducting wire 120, and the superconducting wire 120 can be directly fixed in the winding groove 1111 to realize the fabrication of the superconducting shimming coil 100. Moreover, the superconducting wire 120 does not need to be bent during winding, and can be directly placed in the winding groove 1111, which is convenient to operate and facilitates the fabrication of the superconducting shimming coil 100. At the same time, it can also ensure that the superconducting wire 120 generates a uniform main magnetic field when working, ensuring the performance of the magnetic resonance equipment and thus ensuring the accuracy of the imaging results.

[0073] Optionally, the winding spool 110 is made of a non-magnetic or weakly magnetic material. Further, the winding spool 110 is made of materials such as stainless steel, aluminum alloy, copper, or epoxy resin. Optionally, the winding spool 110 can be manufactured by casting or rolling.

[0074] In one embodiment, the winding groove 1111 is formed using a five-axis machining equipment. It is understood that because the winding groove 1111 is calculated using Harmonic expressions, its wiring trajectory is an asymmetrical closed structure. This structure is difficult to machine; therefore, it is achieved using a five-axis machining equipment. Specifically, the wiring trajectory of the winding groove 1111 is input into the five-axis machining settings, and the winding groove 1111 is machined on the outer periphery of the winding cylinder 110 using the five-axis machining settings.

[0075] Please continue referring to Figure 1. The first saddle-shaped superconducting shimming coil and the second saddle-shaped superconducting shimming coil are respectively set on different support structures (winding cylinders 110), and there is a gap between the two support structures. During the assembly process of the magnetic resonance device C, a winding groove 1111 can be first opened on the side of a winding cylinder 110 facing away from the main magnet 220. The first saddle-shaped superconducting shimming coil is set in the winding groove 1111 to form a first combination. This first combination is close to the main coil and has a gap with the main magnet 220. Another winding cylinder 110 is set outside the aforementioned winding cylinder 110, and a winding groove 1111 is opened on the outer periphery of the other winding cylinder 110. The second saddle-shaped superconducting shimming coil is set in the winding groove 1111 to form a second combination. In this embodiment, the gap between the first combined structure and the main magnet 220 allows cooling medium to flow in, ensuring that the cooling efficiency of the main magnet 220 is not affected by the superconducting shimming coil. The first saddle-shaped superconducting shimming coil and the second saddle-shaped superconducting shimming coil are separated by a winding drum 110 to prevent the heat generated during operation from affecting each other. Furthermore, a gap exists between the two winding drums 110, allowing cooling medium to flow in and cool the first saddle-shaped superconducting shimming coil. See also Figure 2 In one embodiment, each winding groove 1111 has an outlet 1112, which communicates with the outer winding groove 1111. The outlet 1112 of the outermost winding groove 1111 extends through the end of the winding drum 110. A superconducting wire 120 is wound in each winding groove 1111. The winding groove group 111 has a ring-type structure. The inner winding groove 1111 communicates with the outer winding groove 1111 through the outlet 1112. The outermost winding groove 1111 is connected to the end of the winding drum 110 in the axial direction. The outermost outlet 1112 is used to lead the superconducting wire 120 to the outside.

[0076] When the winding spool 110 winds the superconducting wire 120, each winding slot group 111 uses one superconducting wire 120 for winding, and each winding slot 1111 uses one superconducting wire 120 for winding. For example, the superconducting wire 120 is wound n turns (n≥1) with one superconducting wire 120 at the innermost winding slot 1111. After the superconducting wire 120 is wound in the innermost winding slot 1111, it enters the next winding slot 1111 from the outlet 1112 and is wound n turns, and so on. After the superconducting wire 120 is wound in each winding slot 1111 of the winding slot group 111, the superconducting wire 120 is led to the outside.

[0077] In another embodiment, multiple superconducting wires 120 can first be wound into a wire bundle, and the wire bundle can be wound n turns (n≥1) from the innermost to the outermost along the winding groove 1111, with the end of the wire bundle placed near the outlet 1112 in the winding groove 1111. Furthermore, the wire bundle can be connected in series with another wire bundle wound with a saddle-shaped coil.

[0078] For further information, please see [link / reference]. Figure 2 Four shimming coils are arranged on the same circumferential layer of the winding drum 110, and these four superconducting shimming coils can be powered independently. Alternatively, the current lead connectors of two superconducting shimming coils that are symmetrical about the axial direction of the winding drum 110 are connected in series to achieve simultaneous power supply to the two superconducting shimming coils.

[0079] Optionally, the current magnitude of the superconducting wire 120 in each winding slot group 111 is the same, and the current direction of the superconducting wire 120 in at least two winding slots 111 is the same. For example, the current in each winding slot group 111 is the same, and the current directions of adjacent winding slot groups 111 are opposite, such as... Figure 7 As shown, the arrows indicate the direction of the current in the shimming coils. In the same layer of the winding drum 110, four saddle-shaped superconducting shimming coils are symmetrically distributed. The saddle-shaped superconducting shimming coils facing each other relative to the axis of the winding drum 110 have currents flowing in opposite directions but with the same magnitude. Similarly, the saddle-shaped superconducting shimming coils facing each other relative to the center of the winding drum 110 also have currents flowing in opposite directions but with the same magnitude.

[0080] When each winding slot group 111 is wound with a superconducting wire 120, the control of the superconducting uniform coil 100 can be facilitated, the control steps can be simplified, and it is easy to use.

[0081] Optionally, the depth of the outlet 1112 is equal to the depth of the winding groove 1111. This ensures that the radial dimensions of the superconducting wire 120 are consistent in both the outlet 1112 and the winding groove 1111, preventing the wound superconducting wire 120 from being exposed and ensuring performance.

[0082] In one embodiment, each winding slot 1111 is independently arranged, and each winding slot 1111 accommodates one superconducting wire 120. That is, the winding slots 1111 are not connected to each other and are arranged independently. Each winding slot 1111 is an independent channel, and is wound using one superconducting wire 120. During winding, one superconducting wire 120 is wound n turns in one winding slot 1111. Then another superconducting wire 120 is wound n turns in another winding slot 1111, and so on, until all winding slots 1111 are completed.

[0083] Please continue to refer to the appendix. Figure 5Multiple superconducting wires 120 are accommodated in a winding slot 1111, forming a superconducting wire bundle, and adjacent superconducting wires 120 are insulated from each other. This arrangement reduces the number of winding slots 1111 on the winding drum 110 and improves the field uniformity.

[0084] When a superconducting wire 120 is installed in each winding slot 1111, the ends of each superconducting wire 120 are led to the outside to control the superconducting shimming coil 100. Moreover, in the actual control process, the superconducting wire 120 in each winding slot 1111 can be supplied with a corresponding current according to actual needs to adjust the strength of the magnetic field.

[0085] Of course, in other embodiments of this application, some of the winding grooves 1111 may be independent of each other, or some of the winding grooves 1111 may be connected through the outlet 1112. It is worth noting that this embodiment can be implemented by the two winding methods described above, and their principles are essentially the same, so they will not be described in detail here.

[0086] In one embodiment, the winding drum 110 has multiple sets of winding grooves 111, which are symmetrically arranged on the winding drum 110. Exemplarily, there are four winding groove sets 111, which are symmetrically arranged on the outer periphery of the winding drum 110. Two of the winding groove sets 111 are arranged side-by-side along the axial direction of the winding drum 110, and the other two winding groove sets 111 are symmetrically arranged about the central axis of the winding drum 110 about two of the winding groove sets 111.

[0087] See Figure 1 and Figure 5 In one embodiment, the winding groove 1111 has a symmetrical structure. The symmetrical winding groove 1111 ensures the uniformity of the winding, guaranteeing that the superconducting wire 120 is evenly wound within the winding groove 1111. It is worth noting that the shape of the winding groove 1111 is not limited in principle, as long as it is symmetrical on both sides. Optionally, the winding groove 1111 can be square, rectangular, arc-shaped, straight-line spliced, curved-line spliced, straight-line and curved-line spliced, or a dovetail groove, etc.

[0088] See Figure 1 and Figure 5 In one embodiment, the superconducting shimming coil 100 further includes an insulating component 130, which is laid on the inner wall of the winding groove 1111 to isolate the superconducting wire 120 from the winding drum 110. It is understood that the interior of the winding groove 1111 needs to be insulated to prevent direct contact between the superconducting wire 120 and the inner wall of the winding groove 1111. Therefore, the insulating component 130 is laid inside the winding groove 1111 to separate the superconducting wire 120 from the winding drum 110.

[0089] Optionally, the insulating component 130 is fixed to the inner wall of the winding groove 1111 by means of adhesive, threaded parts, or other methods. Optionally, the insulating component 130 is made of insulating material. Exemplarily, the insulating component 130 is insulating varnish, insulating adhesive, insulating paper, insulating fiber products, plastic, rubber, etc.

[0090] In one embodiment, the superconducting shimming coil 100 further includes a binding portion 140, which is used to bind the superconducting wire 120 in the winding groove 1111. The binding portion 140 can fix the superconducting wire 120 in the winding groove 1111, preventing the superconducting wire 120 from slipping out of the winding groove 1111, so that the superconducting wire 120 is reliably located in the winding groove 1111, ensuring the performance of the superconducting shimming coil 100.

[0091] The binding portion includes one or more of a binding tube, a binding band, and a binding strip. In one embodiment, the binding portion 140 forms a cylindrical structure and is sleeved on the outside of the winding tube 110, and contacts the superconducting wire 120 in the winding groove 1111 to fix the superconducting wire 120 in the winding groove 1111. The binding portion 140 confines the superconducting wire 120 in the winding groove 1111, preventing the superconducting wire 120 from detaching from the winding groove 1111.

[0092] Optionally, there may be multiple binding portions 140, which are spaced apart and sleeved on the winding drum 110, each corresponding to the superconducting wire 120 in each winding groove 1111. In other embodiments of this application, the binding portion 140 may be a hollow cylindrical structure, with the binding portion 140 entirely sleeved on the outside of the winding drum 110. For example, the binding portion 140 may be an epoxy resin sleeve.

[0093] Of course, the binding part 140 can also be a component such as a fixing tape or a binding strap that can fix the superconducting wire 120 to the winding groove 1111.

[0094] The superconducting shimming coil 100 of this application effectively solves the problem of the cumbersome winding process of the superconducting wire 120 by fixing the superconducting wire 120 in the winding groove 1111 of the winding cylinder 110. It simplifies the winding process of the superconducting wire 120, and the superconducting wire 120 can be directly fixed in the winding groove 1111 to realize the fabrication of the superconducting shimming coil 100. Moreover, the superconducting wire 120 does not need to be bent during winding, and can be directly placed in the winding groove 1111, which is convenient to operate and facilitates the fabrication of the superconducting shimming coil 100. At the same time, it can also ensure that the superconducting wire 120 generates a uniform main magnetic field when working, ensuring the performance of the magnetic resonance equipment and thus ensuring the accuracy of the imaging results.

[0095] This application also provides a method for fabricating a superconducting shimming coil 100, comprising the following steps:

[0096] The wiring trajectory of the winding groove group 111 on the winding drum 110 is calculated based on the distribution of the main magnetic field.

[0097] The winding grooves 111 are distributed on the winding drum 110 and the winding grooves 111 are machined accordingly.

[0098] A wire harness made of one or more superconducting wires 120 is installed in the winding groove.

[0099] For example, insulation components 130 may be laid in the winding groove assembly 111 first, and then the wire harness may be installed in the winding groove 1111.

[0100] Magnetic resonance imaging (MRI) equipment has specific requirements for the distribution of the main magnetic field. Based on these requirements, the wiring trajectory of the winding groove group 111 on the winding drum 110 is calculated. After the superconducting shimming coil 100 arranges the superconducting wire 120 using the above wiring trajectory, it can ensure that the generated magnetic field is consistent with the magnetic field of the MRI equipment, thus ensuring imaging effect. After determining the wiring trajectory, the corresponding winding groove group 111 is processed on the winding drum 110 according to the wiring trajectory. The superconducting wire 120 is wound into a wire bundle, and the insulating component 130 is laid on the inner wall of the winding groove 1111. The wire bundle is then arranged in the winding groove 1111.

[0101] In one embodiment, the step of calculating the wiring trajectory of the winding slot assembly 111 on the winding drum 110 based on the distribution of the main magnetic field includes:

[0102] The distribution of current density in the winding drum 110 is calculated based on the distribution of the main magnetic field.

[0103] Discretize the current density to obtain the wiring harness trajectory;

[0104] The distribution of winding slots 1111 is determined based on the distribution of the wire harness trajectory.

[0105] When designing the wiring trajectory of the winding slot assembly 111, the current density distribution on the surface of the winding drum 110 is calculated according to the Harmonic expression based on the distribution of the main magnetic field set by the magnetic resonance system. This current density distribution is as follows: Figure 6 As shown in the figure, the ring-shaped area in the middle is the region where the current is concentrated, and the superconducting wire 120 needs to be laid in this region. By discretizing the current density, the wiring trajectory of the winding groove 1111 on the winding drum 110 is obtained, and this wiring trajectory is the wiring trajectory of the superconducting wire 120.

[0106] In one embodiment, the step of machining the winding groove assembly 111 on the winding bobbin 110 includes:

[0107] The five-axis machining equipment is controlled to carve the winding groove group 111 on the winding drum 110 according to the wiring trajectory.

[0108] Understandably, because the winding groove 1111 is calculated using Harmonic expressions, its wiring trajectory is an asymmetrical closed structure. This structure is difficult to manufacture, therefore, it is achieved using a five-axis machining center. Specifically, the wiring trajectory of the winding groove 1111 is input into the five-axis machining settings, and the winding groove 1111 is machined on the outer circumference of the winding drum 110 using these settings.

[0109] In one embodiment, the winding groove assembly 111 includes a plurality of winding grooves 1111, which are nested one inside the other; the step of installing the wire harness in the winding grooves 1111 includes:

[0110] The segmented and shaped wire harness is inserted into the winding groove 1111, and the binding part 140 is used to fix the segmented and shaped wire harness in the winding groove 1111.

[0111] Understandably, the performance of the superconducting shimming coil 100 is ensured in the slot 1111.

[0112] In one embodiment, after the superconducting wire 120 is wound into a wire bundle according to the trajectory of the winding groove, it needs to be segmented and shaped to ensure that the superconducting wire 120 is reliably shaped and positioned. Subsequently, the superconducting wire 120 is fixed in the winding groove 111 and secured by the binding part 140 to prevent the superconducting wire 120 from detaching from the winding groove 1111. The binding part 140 can fix the superconducting wire 120 in the manner described in the above embodiments, which will be described in detail here.

[0113] In one embodiment, the winding groove assembly 111 includes a plurality of winding grooves 1111, which are nested one inside the other; the step of installing the wire harness in the winding grooves 1111 includes:

[0114] A wire outlet 1112 is machined on the winding drum 110. After the superconducting wire 120 is wound once in the winding groove 1111, it enters the next winding groove 1111 through the wire outlet 1112.

[0115] or,

[0116] A superconducting wire 120 is installed in each winding slot 1111.

[0117] Optionally, each winding groove group 111 uses a single superconducting wire 120 to wind multiple winding grooves 1111. Specifically, each winding groove 1111 has an outlet 1112, which communicates with the outer winding groove 1111. The outlet 1112 of the outermost winding groove 1111 extends through the end of the winding drum 110. A single superconducting wire 120 is wound in each winding groove 1111. The winding groove group 111 has a ring-type structure. The inner winding groove 1111 communicates with the outer winding groove 1111 through the outlet 1112. The outermost winding groove 1111 is connected axially to the end of the winding drum 110. The outermost outlet 1112 is used to lead the superconducting wire 120 to the outside.

[0118] When the winding spool 110 winds the superconducting wire 120, each winding slot group 111 uses one superconducting wire 120 for winding, and each winding slot 1111 uses one superconducting wire 120 for winding. For example, the superconducting wire 120 is wound n turns (n≥1) with one superconducting wire 120 at the innermost winding slot 1111. After the superconducting wire 120 is wound in the innermost winding slot 1111, it enters the next winding slot 1111 from the outlet 1112 and is wound n turns, and so on. After the superconducting wire 120 is wound in each winding slot 1111 of the winding slot group 111, the superconducting wire 120 is led to the outside.

[0119] When each winding slot group 111 is wound with a superconducting wire 120, the control of the superconducting uniform coil 100 can be facilitated, the control steps can be simplified, and it is easy to use.

[0120] Optionally, each winding slot 1111 of the winding slot group 111 is wound with a single superconducting wire 120. Specifically, each winding slot 1111 is set independently, and each winding slot 1111 accommodates one superconducting wire 120. That is, the winding slots 1111 are not connected to each other and are set independently. Each winding slot 1111 is an independent channel and is wound with a single superconducting wire 120. During winding, a superconducting wire 120 is wound n turns in one winding slot 1111. Then another superconducting wire 120 is wound n turns in another winding slot 1111, and so on, until all winding slots 1111 are wound.

[0121] When a superconducting wire 120 is installed in each winding slot 1111, the ends of each superconducting wire 120 are led to the outside to control the superconducting shimming coil 100. Moreover, in the actual control process, the superconducting wire 120 in each winding slot 1111 can be supplied with a corresponding current according to actual needs to adjust the strength of the magnetic field.

[0122] Of course, in other embodiments of this application, some of the winding grooves 1111 may be independent of each other, or some of the winding grooves 1111 may be connected through the outlet 1112. It is worth noting that this embodiment can be implemented by the two winding methods described above, and their principles are essentially the same, so they will not be described in detail here.

[0123] This application also provides a magnetic resonance device, including a cryogenic holder; a main magnet disposed inside the cryogenic holder, the main magnet including a main coil and a main coil frame for supporting the main coil; a winding bracket disposed inside the cryogenic holder and located on the outer periphery of the main magnet, the winding bracket having a winding groove; and a saddle-shaped coil disposed in the winding groove.

[0124] In one embodiment, the saddle-shaped coil is supported by a superconducting wire, and the corresponding magnetic resonance device includes a cryogenic holder and a superconducting shimming coil 100, which is installed in the cryogenic holder. The superconducting shimming coil 100 includes a winding drum 110 and a superconducting wire 120. The winding drum 110 has a saddle-shaped winding groove group 111, which includes a plurality of nested winding grooves 1111 (spreading outwards from the center). The superconducting wire 120 is disposed in the winding grooves 1111.

[0125] The winding support can be configured as a winding cylinder sleeved around the outside of the main coil. Please refer to the appendix. Figure 8 This is a schematic diagram of the winding support structure in an embodiment of this application. The winding support includes a first winding cylinder 110-1 and a second winding cylinder 110-2, and the second winding cylinder 110-2 is fixed to the outer periphery of the first winding cylinder 110-1 by an end fixing component. Specifically, the first winding cylinder 110-1, on which a saddle-shaped coil is mounted, can be first sleeved on the outside of the main coil frame 221. The two are fixed by setting a fixing component 400 at the end. The fixing component may include a fixing strip, one end of which extends to the main coil frame 221, and the other end of which extends to the first winding cylinder 110-1. The two ends of the fixing strip are respectively connected by threads. Of course, in this embodiment, the fixing method of the main coil frame 221 and the first winding cylinder 110-1 is not specifically limited. For example, various connection methods such as keys, hooks, splines, pins, welding, gluing, and riveting can also be used. The second winding cylinder 110-2 is provided on the outside of the first winding cylinder 110-1. The two are fixed by the fixing component 400 as mentioned above. Understandably, the number of winding drum layers in the winding bracket can be set according to the actual field uniformity requirements. In the case of field strength of 5 Tesla, 7 Tesla or higher, three, four or more layers of winding drums can be set.

[0126] It is worth noting that the structure of the superconducting shimming coil 100 has already been mentioned above and will not be repeated here. The superconducting shimming coil 100 of the magnetic resonance imaging (MRI) device of this application is installed in a cryogenic holder. When operating, the superconducting shimming coil 100 can generate a magnetic field to image the location of the patient's lesion. By using the superconducting shimming coil 100 of the above embodiment, the MRI device of this application simplifies the manufacturing process, facilitates processing and manufacturing, reduces production costs, and ensures the uniformity of the magnetic field, thereby ensuring accurate imaging results and facilitating diagnosis.

[0127] 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 are 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.

[0128] 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. A superconducting shimming coil, applicable to a magnetic resonance imaging (MRI) device, the MRI device comprising a superconducting magnet, the superconducting magnet comprising a main coil, a main coil frame for supporting the main coil, a shielding coil, and a shielding coil frame for fixing and supporting the shielding coil, the shielding coil frame being disposed outside the main coil frame, characterized in that, The superconducting shimming coil is disposed in the space between the main coil frame and the shielding coil frame, and the superconducting shimming coil includes: A winding drum having a saddle-shaped winding groove group, the winding groove group comprising multiple nested winding grooves, each winding groove being closed. A superconducting wire is disposed in the winding groove, forming a first superconducting shimming coil and a second superconducting shimming coil. The first superconducting shimming coil is disposed adjacent to the main coil, and the second superconducting shimming coil is disposed outside the first superconducting shimming coil. The first superconducting shimming coil and the second superconducting shimming coil are respectively disposed on different winding drums, and there is a gap between the two winding drums. There is a gap between the winding drum containing the first superconducting shimming coil and the main coil. The density of the main coil contained in the first superconducting shimming coil is greater than the density of the main coil contained in the second superconducting shimming coil.

2. The superconducting shimming coil according to claim 1, characterized in that, Each of the winding slots has a wire outlet, which communicates with the outer winding slot; Not less than one of the superconducting wires is wound in each winding slot.

3. The superconducting shimming coil according to claim 2, characterized in that, The winding drum has multiple sets of winding grooves, which are regularly arranged on the winding drum.

4. The superconducting shimming coil according to any one of claims 1 to 3, characterized in that, The superconducting shimming coil also includes an insulating component, which is laid on the inner wall of the winding groove.

5. The superconducting shimming coil according to any one of claims 1 to 3, characterized in that, The superconducting shimming coil also includes a binding part, which is sleeved on the outside of the winding drum to fix the superconducting wire in the winding groove.

6. A method for fabricating a superconducting shimming coil as described in any one of claims 1-5, characterized in that, Includes the following steps: The distribution of the winding slots on the winding drum is calculated based on the distribution of the main magnetic field. The winding grooves are processed on the winding drum according to the distribution of the winding grooves; A wire bundle made of one or more superconducting wires is installed in the winding groove.

7. The method for fabricating a superconducting shimming coil according to claim 6, characterized in that, The steps for calculating the distribution of the winding slots based on the distribution of the main magnetic field include: The distribution of the current density in the winding drum is calculated based on the distribution of the main magnetic field. The current density is discretized to obtain the wire harness trajectory distribution; The distribution of the winding slots is determined based on the distribution of the wire harness trajectory.

8. The method for fabricating a superconducting shimming coil according to claim 6, characterized in that, The step of machining the winding groove assembly on the winding bobbin includes: A cylinder is provided, and the surface of the cylinder is finished. The winding grooves are formed by etching on the surface of the cylinder.

9. The method for fabricating a superconducting shimming coil according to claim 6, characterized in that, The winding groove group includes multiple winding grooves, and the multiple winding grooves are nested in layers; The step of installing a wire bundle made of multiple superconducting wires into the winding groove includes: The wire harness is segmented and shaped; The segmented and shaped wire harness is inserted into the winding groove, and a fixing device is used to fix the segmented and shaped wire harness in the winding groove.

10. A magnetic resonance imaging device, characterized in that, It includes a cryogenic holder, a superconducting magnet, and a superconducting shimming coil, wherein the superconducting shimming coil is installed in the cryogenic holder; The superconducting magnet includes a main coil, a main coil frame for supporting the main coil, a shielding coil, and a shielding coil frame for fixing and supporting the shielding coil. The shielding coil frame is disposed outside the main coil frame, and the superconducting shimming coil is disposed in the space between the main coil frame and the shielding coil frame. The superconducting shimming coil includes: A winding drum having a saddle-shaped winding groove group, the winding groove group comprising multiple nested winding grooves, each winding groove being closed. A superconducting wire is disposed in the winding groove, forming a first superconducting shimming coil and a second superconducting shimming coil. The first superconducting shimming coil is disposed adjacent to the main coil, and the second superconducting shimming coil is disposed outside the first superconducting shimming coil. The first superconducting shimming coil and the second superconducting shimming coil are respectively disposed on different winding drums, and there is a gap between the two winding drums. There is a gap between the winding drum containing the first superconducting shimming coil and the main coil. The density of the main coil contained in the first superconducting shimming coil is greater than the density of the main coil contained in the second superconducting shimming coil.

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