Gradient coil and magnetic resonance imaging device

Abstract

This invention relates to a gradient coil and a magnetic resonance imaging device. The gradient coil includes a main coil and a shielding coil connected to each other. Both the main coil and the shielding coil include X, Y, and Z gradient coils arranged sequentially in the radial direction. The X and Y gradient coils include multiple conductor structures, each conductor structure including multiple parallel conductive coil units. The conductive coil units are configured to be wound with multiple turns of hollow wire according to a preset trajectory. The conductor structure layer also includes an electro-hydraulic circuit separation device. Each conductive coil unit is equipped with an electro-hydraulic circuit separation device, which is located on the outside of the wound portion of the conductive coil unit. The electro-hydraulic circuit separation device is connected to the hollow wire. The multiple turns of hollow wire in the same conductive coil unit form a series circuit and a parallel liquid circuit through the electro-hydraulic circuit separation device.

Description

Technical Field

[0001] This invention relates to the field of magnetic resonance imaging and its applications, and in particular to a gradient coil and a magnetic resonance imaging device. Background Technology

[0002] Scientific research in the fields of magnetic resonance imaging (MRI) and its applications has placed increasingly higher demands on gradient performance. In an MRI system, a traditional gradient coil consists of three main gradient coils (GX, GY, GZ) and three shielded gradient coils (SX, SY, SZ). A gradient power amplifier drives the three main gradient coils (GX, GY, GZ) to generate gradient magnetic fields in the X, Y, and Z directions to meet the imaging requirements of the MRI system. The three shielded gradient coils (SX, SY, SZ) provide shielded gradient magnetic fields in the X, Y, and Z directions, respectively. The X and Y coils are fingerprint-shaped coils, while the Z coil is a helical coil. These six coils are fabricated into a cylindrical structure and coaxially assembled, then encapsulated together with epoxy resin to form a cylindrical coil.

[0003] To improve the performance of gradient coils, more turns are needed within them. Existing technology uses hollow tubular material to fabricate gradient coils, providing a conduit for coolant delivery while simultaneously energizing the conductor. However, in this technology, the hollow conductor is wound spirally from beginning to end, resulting in a long hollow conductor path through which coolant flows. As the coolant flows from beginning to end, it experiences friction, resistance, and flow obstruction, leading to fluid loss, velocity reduction, and energy loss. Furthermore, the water pressure decreases gradually with increasing pipe length as the fluid passes through the hollow conductor tube, making it difficult to meet the design requirements of ultra-high-performance gradient coils. Summary of the Invention

[0004] Therefore, it is necessary to provide a gradient coil and magnetic resonance imaging device to address the technical problems of long conductor cooling paths and low cooling efficiency in existing gradient coils.

[0005] A gradient coil includes a main coil and a shielding coil interconnected. Both the main coil and the shielding coil include an X-gradient coil and a Y-gradient coil. The X-gradient coil and the Y-gradient coil include multiple conductor structures, each conductor structure comprising multiple parallel-arranged conductive coil units. Each conductive coil unit is configured to be wound with multi-turn hollow wire according to a preset trajectory. The conductor structure layer further includes:

[0006] An electro-hydraulic circuit separation device is provided for each of the conductive coil units, and the electro-hydraulic circuit separation device is located outside the winding center of the conductive coil unit. The electro-hydraulic circuit separation device is connected to the hollow wire, and multiple turns of the hollow wire in the same conductive coil unit form a series circuit and a parallel liquid circuit through the electro-hydraulic circuit separation device.

[0007] In one embodiment, the electro / hydraulic circuit separation device is disposed at both ends of the conductor structure layer along the axial direction, and the electro / hydraulic circuit device is composed of multiple electro / hydraulic separators; wherein, the electro / hydraulic separator has an inlet and an outlet, and the inlet and outlet are used for inputting or outputting water and electricity.

[0008] In one embodiment, each of the multiple turns of the hollow conductor includes a first end and a second end, and the hollow conductor is gradually wound outward from the winding center with the first end as the center to form a spiral shape;

[0009] The first end is connected to the corresponding electro / liquid separator, and the circuit and liquid path gathered by the electro / liquid separator are input into the hollow wire through the first end;

[0010] The second end is connected to the corresponding electro / liquid separator, and the converging circuit and liquid flow leave the hollow wire from the second end and are separated by the corresponding electro / liquid separator.

[0011] In one embodiment, the electro / hydraulic circuit separation device further includes a first water separator and a second water separator;

[0012] One end of the first water distributor is connected to the liquid inlet of the cooling system, and the other end is connected to the electro-liquid separator to deliver liquid to the electro-liquid separator;

[0013] One end of the second water distributor is connected to the liquid outlet of the cooling system, and the other end is connected to the electro-hydraulic separator to deliver liquid to the cooling system.

[0014] In one embodiment, the conductive coil unit includes a first hollow wire and a second hollow wire;

[0015] The water inlets of the first electro-liquid separator and the second electro-liquid separator are respectively connected to the first water distributor, and the first ends of the first hollow wire and the second hollow wire are input through the integrated interface;

[0016] The second ends of the first hollow conductor and the second hollow conductor are respectively output to the second water distributor through the water outlet of the second electro-liquid separator and the third electro-liquid separator.

[0017] In one embodiment, both the X gradient coil and the Y gradient coil include a first conductor structure and a second conductor structure spaced apart, the first conductor structure and the second conductor structure being arranged symmetrically along the radial direction of the gradient coil, and the gap between the first conductor structure and the second conductor structure forming a lead-out groove;

[0018] The lead-out slots located in the X gradient coil and the lead-out slots located in the Y gradient coil are staggered in the circumferential direction of the gradient coils.

[0019] In one embodiment, the first end of the multiple turns of the hollow wire is connected to the electro-hydraulic separation device via a lead wire;

[0020] The X-gradient coil leads are placed in the Y-gradient coil leads, and the Y-gradient coil leads are placed in the X-gradient coil leads.

[0021] In one embodiment, the conductor structure further includes a support plate, the conductive coil unit is supported and fixed on the support plate, and the support plate is bent into a cylindrical or semi-cylindrical structure;

[0022] The conductor structure layer includes two opposing conductor structures that form a cylindrical structure.

[0023] A magnetic resonance imaging (MRI) device includes a gradient coil, the gradient coil comprising:

[0024] The main coil includes the X gradient coil and the Y gradient coil;

[0025] A shielding coil is disposed outside the main coil, and the main coil and the shielding coil are arranged to form a cylindrical structure, the cylindrical structure having two opposing ends;

[0026] The X gradient coil or the Y gradient coil includes a plurality of conductive coil units arranged in parallel, at least one of the conductive coil units is configured to be wound by wires according to a preset trajectory, at least part of the conductive coil unit is a hollow wire, and the hollow wire contains coolant.

[0027] An electro-hydraulic circuit separation device is disposed at at least one end of the cylindrical structure, and the electro-hydraulic circuit separation device is connected to the hollow conductor to achieve separation of the current flowing through the hollow conductor from the coolant at the end.

[0028] In one embodiment, the conductive coil unit comprises two parallel wires wound along a preset trajectory, one of which is a hollow wire and the other is a solid wire; or, both are hollow wires.

[0029] The beneficial effects of this invention are:

[0030] This invention provides a gradient coil. The main coil is primarily used to generate a gradient magnetic field that is linearly distributed in space. Through pulse sequences, the amplitude of the gradient magnetic field can be controlled temporally. This causes the precession frequency of nuclei in the imaging region to vary with their spatial position, achieving spatial encoding of nuclei signals in the imaged object. The shielding coil is mainly used to shield external interference, effectively reducing the influence of external electromagnetic waves on internal electronic components, thereby reducing noise and ensuring imaging quality. The shielding coil is located outside the main coil, with a gap between them. The main coil and the shielding coil have the same structure, both including an X-gradient coil and a Y-gradient coil. The X-gradient coil and the Y-gradient coil include multiple conductor structures, each conductor structure including multiple parallel conductive coil units. The performance of the gradient coil is improved by configuring each conductive coil unit with multiple turns of hollow wire wound along a preset trajectory. Furthermore, by configuring an electro-hydraulic circuit separation device for each conductive coil unit, the water circuits of each conductive coil unit are independent and do not affect each other. The electro-hydraulic circuit separation device is located on the outside of the winding portion of the conductive coil unit for easy wiring. The circuits in the multi-turn hollow wires of each conductive coil unit are set in series to enable the conductive coil unit to generate a gradient magnetic field, while the water path of the multi-turn hollow wires in each conductive coil unit is set in parallel to shorten the water path and thus improve cooling efficiency. Attached Figure Description

[0031] Figure 1 This is a top view of a conductor structure layer in a gradient coil according to an embodiment of the present invention;

[0032] Figure 2 This is a three-dimensional structural diagram of a conductor structure layer in a gradient coil according to an embodiment of the present invention;

[0033] Figure 3 A side view of a gradient coil provided in an embodiment of the present invention;

[0034] Figure 4 This is a three-dimensional structural schematic diagram of a gradient coil provided in an embodiment of the present invention;

[0035] Figure 5 This is a partially enlarged schematic diagram of a gradient coil provided in an embodiment of the present invention;

[0036] Figure 6 This is a partially enlarged side view of a gradient coil provided in an embodiment of the present invention;

[0037] Figure 7 This is a schematic diagram of the arrangement of multiple hollow wires in a gradient coil according to an embodiment of the present invention;

[0038] Figure 8 A top view of a conductor structure layer in a gradient coil provided in another embodiment of the present invention;

[0039] Figure 9 This is a top view of a conductor structure layer in a gradient coil provided in another embodiment of the present invention.

[0040] Figure label:

[0041] Main coil 10; support plate 110; conductive coil unit 120; first hollow wire 121; first end 1211; second end 1212; second hollow wire 122; lead-out slot 130; X gradient coil 140; Y gradient coil 150; Z gradient coil 160; lead-out wire 170; electro-hydraulic circuit separation device 200; first electro-hydraulic separator 210; second electro-hydraulic separator 220; third electro-hydraulic separator 230; first water distributor 240; second water distributor 250; electro-hydraulic converter 260; main water distributor 270; shielded coil 20. Detailed Implementation

[0042] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be 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 the present invention. However, the present invention can be practiced 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 the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0043] In the description of this invention, 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," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention 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. Therefore, they should not be construed as limitations on this invention.

[0044] 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 invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0045] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," 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 explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0046] In this invention, unless otherwise explicitly 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," "over," and "on top" of 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.

[0047] 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.

[0048] See Figures 1 to 7 An embodiment of the present invention provides a gradient coil, which includes a main coil 10 and a shielding coil 20 connected to each other. Both the main coil 10 and the shielding coil 20 include X, Y, and Z gradient coils arranged radially. The X gradient coil 140 and the Y gradient coil 150 include multiple conductor structures, each conductor structure including multiple parallel conductive coil units. The conductive coil units are configured to be wound by multiple turns of hollow wire according to a preset trajectory. The conductor structure layer also includes an electrical / liquid circuit separation device. Each conductive coil unit is equipped with an electrical / liquid circuit separation device, and the electrical / liquid circuit separation device is located on the outside of the wound portion of the conductive coil unit. The electrical / liquid circuit separation device 200 is connected to the hollow wire. The multiple turns of hollow wire in the same conductive coil unit 120 form a series circuit and a parallel liquid circuit through the electrical / liquid circuit separation device.

[0049] This technical solution provides a gradient coil. The main coil 10 is primarily used to generate a gradient magnetic field that is linearly distributed in space. Through pulse sequences, the amplitude of the gradient magnetic field can be controlled temporally. This causes the precession frequency of nuclei in the imaging region to vary with their spatial position, achieving spatial encoding of nuclei signals in the imaging object. The shielding coil 20 is mainly used to shield external interference, effectively reducing the influence of external electromagnetic waves on internal electronic components, thereby reducing noise and ensuring imaging quality. The shielding coil is located outside the main coil 10, with a gap between them. The main coil 10 and the shielding coil 20 have the same structure, both including X, Y, and Z gradient coils arranged radially. The X gradient coil 140 and Y gradient coil 150 have conductor structures, each conductor structure including multiple parallel conductive coil units. By setting each conductive coil unit to be wound with multiple turns of hollow wire according to a preset trajectory, the performance of the gradient coil is improved. By configuring an electro-hydraulic circuit separation device for each conductive coil unit, the water circuits of each conductive coil unit are made independent and do not affect each other. Furthermore, the electro-hydraulic circuit separation device 200 is positioned outside the winding center of the conductive coil unit to facilitate wiring. The winding center can be understood as... Figure 1 As shown, the eye is formed by the first spiral winding. The circuits in the multi-turn hollow wires of each conductive coil unit are set in series to facilitate the generation of a gradient magnetic field by the conductive coil unit, while the water channels in the multi-turn hollow wires of each conductive coil unit are set in parallel to shorten the water path and thus improve cooling efficiency.

[0050] Specifically, the hollow conductor is a copper tube, with the tube itself acting as a conductor to transmit current, and the inner hole for coolant flow. The cross-section of the hollow conductor can be circular, flat, or rectangular, and its specific shape is not limited.

[0051] like Figure 1 and Figure 2 As shown, in one embodiment, the conductor structure further includes a support plate 110, on which the conductive coil unit is supported and fixed. The support plate 110 is bent into a cylindrical or semi-cylindrical structure. Specifically, part or all of the hollow wire is embedded in the support plate 110. The support plate 110 serves to support and fix the conductive coil unit, and also provides insulation. Bending the support plate 110 into a cylindrical or semi-cylindrical structure allows the conductive coil to deform integrally with the support plate 110.

[0052] like Figures 3 to 5As shown, in one embodiment, both the X gradient coil 140 and the Y gradient coil 150 include a first conductor structure and a second conductor structure spaced apart. The first conductor structure and the second conductor structure are arranged symmetrically along the radial direction of the gradient coil, and the gap between the first conductor structure and the second conductor structure forms a lead-out slot 130. The lead-out slot 130 located in the X gradient coil 140 and the lead-out slot 130 located in the Y gradient coil 150 are staggered in the circumferential direction of the gradient coil.

[0053] Specifically, both the X gradient coil 140 and the Y gradient coil 150 include two opposing conductor structures. The support plates 110 in the two conductor structures are spaced apart. The support plate 110 in each conductor structure is bent to form a semi-cylindrical structure. The support plates 110 in the two opposing conductor structures form a cylindrical structure, thereby forming a gradient magnetic field in the entire circumference, thus ensuring the scanning effect.

[0054] By forming lead-out slots 130 in the X gradient coil 140 and Y gradient coil 150, lead-out lines 170 connecting the electrical and liquid circuits between the conductive coil unit and the electro / liquid circuit separation device 200 are led out from the lead-out slots 130.

[0055] Specifically, the gap between the two conductor structures in the same layer of the X gradient coil 140 and the Y gradient coil 150 is formed as a lead-out groove 130; the lead-out wires 170 of each turn of hollow wire in the same layer are arranged side by side and led out from the lead-out groove 130, and the radial width of the hollow wires in the same layer in the lead-out wire 170 is smaller than the groove width of the lead-out groove 130.

[0056] It is understandable that the entire gradient coil includes three directions: X-axis, Y-axis, and Z-axis. When the patient is supine with their head first, defining the coordinate system of the MRI equipment, the axial direction of the cylinder, i.e., from the patient's feet towards the head, is the Z-axis. The X-axis and Y-axis are perpendicular to the Z-axis. The X-axis points to the left side of the anatomical position, while the Y-axis points to the front. There are one or more gradient coils along each of the X, Y, and Z axes, and the gradient magnetic field generated after energization is distributed along the corresponding axis.

[0057] In one embodiment, the lead-out slots 130 on the X-gradient coil 140 and the Y-gradient coil 150 are staggered. The stagger angle between the lead-out slots 130 of the X-gradient coil 140 and the Y-gradient coil 150 is 90 degrees. Figure 6As shown, starting from the inside, the innermost layer is the X gradient coil 140, which includes two spaced-apart semicircular saddle-shaped coils distributed in the 0° and 180° directions; the middle layer is the Y gradient coil 150, which also includes two spaced-apart semicircular saddle-shaped coils distributed in the 90° and 270° directions; the outermost layer is the Z gradient coil 160, which is a complete cylindrical structure. This arrangement is to form gradient magnetic fields in the X, Y, and Z directions.

[0058] The first end 1211 of the multi-turn hollow wire is connected to the electro-hydraulic separation device through the lead wire 170; wherein, each lead wire 170 corresponding to the X gradient coil 140 is placed in the lead slot 130 of the Y gradient coil 150, and each lead wire 170 corresponding to the Y gradient coil 150 is placed in the lead slot 130 of the X gradient coil 140.

[0059] like Figures 3 to 5 As shown, from the inside out along the radial direction of the gradient coils, the coils are arranged as follows: X gradient coil 140, Y gradient coil 150, and Z gradient coil 160. The gap between the two conductor structures is a lead-out slot 130. Parallel lead-out wires of the conductor structure layers are arranged within the lead-out slot 130. Leading out the lead-out wire 170 of the X gradient coil 140 from the lead-out slot 130 of the Y gradient coil 150, and vice versa, reduces the travel of the lead-out wires, thereby shortening the water path and improving cooling efficiency. With the gradient coil performance unchanged, the gap size of the saddle-shaped coil is fixed. The more lead-out wires it can accommodate, the shorter the water path, and the higher the cooling efficiency.

[0060] In one embodiment, the electro / hydraulic circuit separation device 200 is disposed at both ends of the conductor structure layer along the axial direction, and the electro / hydraulic circuit device is composed of multiple electro / hydraulic separators; wherein, the electro / hydraulic separator has an inlet and an outlet, and the inlet and outlet are used for inputting or outputting water and electricity.

[0061] The electro-hydraulic circuit separation device 200 is set at both ends of the conductor structure layer along the axial direction, which facilitates the connection of the circuit and water circuit of the electro-hydraulic circuit separation device 200 with the conductive coil unit, cooling system and external circuit, thereby facilitating the arrangement of pipelines.

[0062] Furthermore, each of the multi-turn hollow conductors includes a first end 1211 and a second end 1212. The hollow conductor is wound outward from the winding center with the first end 1211 as the center to form a spiral shape. The first end 1211 is connected to the corresponding electro-liquid separator. The circuit and liquid paths gathered by the electro-liquid separator are input into the hollow conductor through the first end 1211. The second end 1212 is connected to the corresponding electro-liquid separator. The gathered circuit and liquid paths leave the hollow conductor from the second end 1212 and are separated by the corresponding electro-liquid separator.

[0063] The aforementioned conductive coil unit is formed by gradually winding multiple turns of hollow wire arranged side by side in a spiral shape from the first end 1211 to the second end 1212 along the winding center. The first end 1211 of the hollow wire is connected to a corresponding electro-hydraulic separator, allowing the circuit and liquid paths to be input into the hollow wire through the separator. The second end 1212 of the hollow wire is connected to the corresponding electro-hydraulic separator, allowing the current and coolant on the hollow wire to be output from the second end 1212. This structural configuration forms a series circuit and a parallel liquid path within the conductive coil unit.

[0064] In one embodiment, the electro / hydraulic separation device 200 further includes a first water distributor 240 and a second water distributor 250; one end of the first water distributor 240 is connected to the liquid inlet of the cooling system, and the other end is connected to the electro / hydraulic separator to deliver liquid to the electro / hydraulic separator; one end of the second water distributor 250 is connected to the liquid outlet of the cooling system, and the other end is connected to the electro / hydraulic separator to deliver liquid to the cooling system.

[0065] By setting up a first water distributor 240 and a second water distributor 250, the first water distributor 240 connects the inlet of the cooling system to the electro-liquid separator, so as to deliver coolant into the electro-liquid separator; the second water distributor 250 connects the outlet of the cooling system to the electro-liquid separator, so that the coolant that has undergone heat exchange in the conductive coil unit flows out from the second water distributor 250 and flows into the cooling system, thereby realizing the circulation of coolant.

[0066] Specifically, the conductive coil unit includes a first hollow wire 121 and a second hollow wire 122; the water inlets of the first electro-liquid separator 210 and the second electro-liquid separator 220 are respectively connected to the first water distributor 240, and the first ends 1211 of the first hollow wire 121 and the second hollow wire 122 are input through the integrated interface; the second ends 1212 of the first hollow wire 121 and the second hollow wire 122 are respectively output to the second water distributor 250 through the water outlets of the second electro-liquid separator 220 and the third electro-liquid separator 230.

[0067] By setting it up as described above, the cooling water circuits inside the conductive coil are connected in parallel, thereby shortening the water path and improving cooling efficiency.

[0068] In one embodiment, current is connected to the circuit of the first electro-liquid separator 210 and input to the first end 1211 of the first hollow wire 121 through the first electro-liquid separator 210; the current is output to the second electro-liquid separator 220 through the second end 1212 of the first hollow wire 121 and input to the first end 1211 of the second hollow wire 122 through the wire provided on the second electro-liquid separator 220; after flowing through the hollow wire, the current is input to the circuit inlet of the third electro-liquid separator 230 from the second end 1212 of the second hollow wire 122.

[0069] The above setup enables the circuitry within the conductive coil unit to be connected in series, thereby facilitating the generation of a gradient magnetic field within the conductive coil unit; for example... Figure 1 and Figure 2 As shown, further, each of the first ends 1211 of the first hollow conductor 121 and the first ends 1211 of the second hollow conductor is provided with an electro-hydraulic converter 260. The first electro-hydraulic separator 210 is connected to the electro-hydraulic converter 260 of the first hollow conductor 121, and the circuit and water circuit of the second electro-hydraulic separator 220 are connected to the electro-hydraulic converter 260 on the second hollow conductor.

[0070] like Figure 1 and Figure 2 As shown, specifically, current is input from the black arrow of the first electro-hydraulic separator 210, while cooling water is input from the first water distributor 240 into the inlet water path of the first electro-hydraulic separator 210. At the outlet of the first electro-hydraulic separator 210, the current converges and enters the conductive pipe, then flows together into the electro-hydraulic converter 260 at the first end 1211 of the first hollow conductor 121. The current then flows into the first hollow conductor 121, winding along its path to the second electro-hydraulic separator 220. At this time, the current in the first hollow conductor 121 flows through the conductor and the second electro-hydraulic separator 220 into the electro-hydraulic converter 260 at the first end 1211 of the second hollow conductor, and through this converter 260 into the second hollow conductor. Finally, it flows from the second end 1212 of the second hollow conductor into the third electro-hydraulic separator 230 and is output.

[0071] Cooling water for the first hollow conductor 121 enters the inlet pipe of the first electro-hydraulic separator 210 from the first water distributor 240, flows through the winding path of the first hollow conductor 121, flows through the outlet water path of the second electro-hydraulic separator 220 into the second water distributor 250, and then into the external cooling system. Correspondingly, cooling water for the second hollow conductor enters the inlet water path of the second electro-hydraulic separator 220 from the first water distributor 240, flows through the winding path of the second hollow conductor, flows through the outlet water path of the third electro-hydraulic separator 230 into the second water distributor 250, and then into the external cooling system.

[0072] The above connection method enables the circuits of the first hollow wire 121 and the second hollow conductor to be connected in series, and the cooling water path to be connected in parallel.

[0073] It is understood that the cooling water for each conductor structure layer enters through a main inlet into the corresponding first distributor 240 of each layer, then flows through the hollow conductor to the corresponding second distributor 250 of each layer, and finally flows out through the same main outlet. The cooling water for each layer is collected and directed to the same end. It should be understood that the cooling water for the main coil 10 and the shield coil 20 enters through the same main inlet into the corresponding first distributor 240 of the conductor structure layer, flows out through the corresponding second distributor 250 of the conductor structure layer, and flows out through the main outlet. Specifically, the main outlet and main inlet are located on a main distributor 270, and a main distributor 270 is located at each end of the gradient coil.

[0074] It should be understood that the first hollow conductor 121 and the second hollow conductor 122 are substantially parallel. In another embodiment, the hollow conductor may have two, three, or even more turns.

[0075] like Figure 8 As shown, in one embodiment, each conductor structure includes two conductive coil units 120, the circuits of the two conductive coil units 120 are connected in series, and the water channels of the two conductive coil units 120 are independent of each other.

[0076] For example, in one embodiment, water and electricity are separated at the center of the coil of the conductive coil unit 120. The circuit runs directly from one conductive coil unit 120 to another via a wire, and the water path connects from the center of the conductive coil unit 120 to both sides of the gradient. It is understood that the water path connection can be directly replaced with a non-metallic water pipe at the center of the coil, or a hollow wire can be connected to both sides of the gradient first, and then connected to a non-metallic water pipe on both sides of the gradient. Figure 8As shown, the current is input along the black arrow of the first electro-hydraulic circuit separator 200, while the cooling water is input from the water distributor into the water inlet of the first electro-hydraulic circuit separator 200. At the outlet of the first electro-hydraulic separator 210, the current converges and is input into the first hollow conductor 121, and then together they are input into the electro-hydraulic converter 260 of the first hollow conductor 121. The current is wound along the path to the second electro-hydraulic separator 220. Here, the current in the first hollow conductor 121 in the circuit is input into the winding path of the second hollow conductor through the conductor. The cooling water in the first hollow conductor 121 is output through the second electro-hydraulic separator 220 and enters the cooling cycle of the external system of the gradient coil. Cooling water enters from the distributor along the inlet water path of the second electro-hydraulic separator 220. Water and electricity are simultaneously input into the winding path of the second hollow conductor via wires. Current is connected to the first hollow conductor 121 of another conductive coil unit 120 via a solid wire, thus inputting current into the other conductive coil unit 120. Cooling water exits through a non-metallic water pipe into the external cooling circulation system of the gradient coil. With this connection method, the circuits of the first hollow conductor 121 and the second hollow conductor are connected in series, while the cooling water paths of the first hollow conductor 121 and the second hollow conductor are connected in parallel.

[0077] like Figure 9 As shown, in another embodiment, the first electro-hydraulic separator 210 and the second electro-hydraulic separator 220 can be positioned at the center of the conductive coil unit 120. The current input is a solid, good conductor, and the cooling water input is a non-metallic conduit. The water and electricity enter the conductive coil unit 120 through the first electro-hydraulic separator 210 and the second electro-hydraulic separator 220 to form a spiral gradient coil. After passing through a water-electricity conversion connector, the cooling water in the first hollow conductor 121 flows out into the external cooling circulation system. The current continues to be input to the second hollow conductor and even the nth turn of the hollow conductor, and so on. The other part of the gradient coil is the conductive coil unit 120.

[0078] An embodiment of the present invention also provides a magnetic resonance imaging device, which includes gradient coils. The gradient coils include a main coil 10, a shielding coil 20, and an electro-hydraulic circuit separation device 200. The main coil 10 includes an X gradient coil 140 and a Y gradient coil 150. The shielding coil 20 is disposed outside the main coil 10. The main coil 10 and the shielding coil 20 are arranged to form a cylindrical structure, which has two opposite ends. The X gradient coil 140 or the Y gradient coil 150 includes a plurality of parallel conductive coil units 120. At least one conductive coil unit 120 is configured to be wound by a wire according to a preset trajectory. At least a portion of the wound conductive coil unit 120 is a hollow wire, which contains coolant. The electro-hydraulic circuit separation device 200 is disposed at at least one end of the cylindrical structure and is connected to the hollow wire to separate the current flowing through the hollow wire from the coolant at the end.

[0079] This application provides a magnetic resonance imaging device. The main coil 10 is primarily used to generate a gradient magnetic field that is linearly distributed in space. Through pulse sequences, the amplitude of the gradient magnetic field can be controlled temporally. This causes the precession frequency of nuclei in the imaging region to vary with their spatial position, achieving spatial encoding of nuclei signals in the imaged object. The shielding coil 20 is mainly used to shield external interference, effectively reducing the influence of external electromagnetic waves on internal electronic components, thereby reducing noise and ensuring imaging quality. The shielding coil is located outside the main coil, with a gap between them. By arranging the X gradient coil 140 and Y gradient coil 150 as a parallel conductive coil unit 120, and setting the conductive coil unit 120 to be wound with wires according to a preset trajectory, the performance of the gradient coils is improved. At least a portion of the conductive coil unit 120 is a hollow wire to accommodate coolant, thereby cooling the conductive coil unit 120 and improving the performance of the gradient coils. By installing an electrical / hydraulic circuit separation device 200 at the ends of the main coil and the shielding coil, the current flowing through the hollow conductive core and the coolant are separated, thereby enabling the supply of power and coolant to the main coil and the shielding coil.

[0080] In one embodiment, the conductive coil unit 120 comprises two parallel wires wound along a preset trajectory, one of which is a hollow wire and the other is a solid wire; or both are hollow wires. In this embodiment, by setting at least one of the wires winding the conductive coil unit 120 as a hollow wire, coolant can flow through it, thereby dissipating heat and cooling the conductive coil unit.

[0081] The gradient coil provided in this invention uses a multi-turn hollow conductor and water-electricity separation devices at both ends to form a series circuit and parallel water path. The hollow conductor coil's lead wire 170 of the X gradient coil 140 is located in the gap between the two saddle-shaped coils of the Y gradient coil 150, and the Y gradient coil 150's lead wire is also located in the gap between the two saddle-shaped coils of the X gradient coil 140. With the gradient coil performance unchanged, the gap size of the saddle-shaped coils is fixed. The more lead wires it can accommodate, the shorter the water path, and the higher the cooling efficiency. The gradient coil provided by this invention can achieve twice the number of lead wires under the same circuit path and the same saddle-shaped coil gap size, thereby shortening the water path by 50%, effectively solving the problem of low cooling efficiency and significantly improving cooling efficiency. With unchanged performance, the heat dissipation effect is improved by more than 70%, resulting in a 30% increase in the equivalent DC gradient intensity Grms.

[0082] 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.

[0083] The embodiments described above are merely illustrative of several implementations of the present invention, 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 the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A gradient coil, characterized in that, The gradient coil includes an interconnected main coil and a shielding coil. Both the main coil and the shielding coil include an X-gradient coil and a Y-gradient coil. The X-gradient coil and the Y-gradient coil include multiple conductor structures, each conductor structure comprising multiple parallel-arranged conductive coil units. Each conductive coil unit is configured to be wound with multi-turn hollow wire according to a preset trajectory. The conductor structure layer further includes: An electro-hydraulic circuit separation device is provided for each of the conductive coil units, and the electro-hydraulic circuit separation device is located outside the winding center of the conductive coil unit. The electro-hydraulic circuit separation device is connected to the hollow wire, and multiple turns of the hollow wire in the same conductive coil unit form a series circuit and a parallel liquid circuit through the electro-hydraulic circuit separation device.

2. The gradient coil according to claim 1, characterized in that, The electro / hydraulic circuit separation device is disposed at both ends of the conductor structure layer along the axial direction. The electro / hydraulic circuit separation device is composed of multiple electro / hydraulic separators. Each electro / hydraulic separator has an inlet and an outlet, which are used for inputting or outputting water and electricity.

3. The gradient coil according to claim 2, characterized in that, Each of the multiple turns of the hollow conductor includes a first end and a second end. The hollow conductor is gradually wound outward from the winding center with the first end as the center to form a spiral shape. The first end is connected to the corresponding electro / liquid separator, and the circuit and liquid path gathered by the electro / liquid separator are input into the hollow wire through the first end; The second end is connected to the corresponding electro / liquid separator, and the converging circuit and liquid flow leave the hollow wire from the second end and are separated by the corresponding electro / liquid separator.

4. The gradient coil according to claim 2, characterized in that, The electro / hydraulic circuit separation device also includes a first water separator and a second water separator. One end of the first water distributor is connected to the liquid inlet of the cooling system, and the other end is connected to the electro-liquid separator to deliver liquid to the electro-liquid separator; One end of the second water distributor is connected to the liquid outlet of the cooling system, and the other end is connected to the electro-hydraulic separator to deliver liquid to the cooling system.

5. The gradient coil according to claim 4, characterized in that, The conductive coil unit includes a first hollow wire and a second hollow wire; the electro-liquid separator includes a first electro-liquid separator, a second electro-liquid separator, and a third electro-liquid separator. The water inlets of the first electro-liquid separator and the second electro-liquid separator are respectively connected to the first water distributor, and are input to the first ports of the first hollow wire and the second hollow wire through a comprehensive interface; The second ports of the first hollow conductor and the second hollow conductor are respectively output to the second water distributor through the water outlets of the second electro-liquid separator and the third electro-liquid separator.

6. The gradient coil according to claim 1, characterized in that, Both the X gradient coil and the Y gradient coil include a first conductor structure and a second conductor structure arranged at intervals. The first conductor structure and the second conductor structure are arranged symmetrically along the radial direction of the gradient coil, and the gap between the first conductor structure and the second conductor structure forms a lead-out groove. The lead-out slots located in the X gradient coil and the lead-out slots located in the Y gradient coil are staggered in the circumferential direction of the gradient coils.

7. The gradient coil according to claim 6, characterized in that, The first end of the multi-turn hollow wire is connected to the electro-hydraulic separation device via a lead wire; The X-gradient coil leads are placed in the Y-gradient coil leads, and the Y-gradient coil leads are placed in the X-gradient coil leads.

8. The gradient coil according to any one of claims 1-7, characterized in that, The conductor structure also includes a support plate, on which the conductive coil unit is supported and fixed. The support plate is bent into a cylindrical or semi-cylindrical structure. The conductor structure layer includes two opposing conductor structures that form a cylindrical structure.

9. A magnetic resonance imaging device, the magnetic resonance imaging device comprising gradient coils, characterized in that, The gradient coil includes: The main coil includes the X gradient coil and the Y gradient coil; A shielding coil is disposed outside the main coil, and the main coil and the shielding coil are arranged to form a cylindrical structure, the cylindrical structure having two opposing ends; The X gradient coil or the Y gradient coil includes a plurality of conductive coil units arranged in parallel, at least one of the conductive coil units is configured to be wound by wires according to a preset trajectory, at least part of the conductive coil unit is a hollow wire, and the hollow wire contains coolant. An electro-hydraulic circuit separation device is disposed at at least one end of the cylindrical structure, and the electro-hydraulic circuit separation device is connected to the hollow conductor to achieve separation of the current flowing through the hollow conductor from the coolant at the end.

10. The magnetic resonance imaging device according to claim 9, characterized in that, The conductive coil unit comprises two parallel wires wound along a preset trajectory, one of which is a hollow wire and the other is a solid wire; or both are hollow wires.

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