Connector for magnetic resonance examination device

Abstract

According to the invention, a connector (1) for galvanically connecting a first terminal (2) of a magnetic resonance examination device (4) with a second terminal (5) of the magnetic resonance examination device (4) comprises: a first superconductor wire (8) having an end region (14) for attachment to the first terminal (2) and an opposite end region (16); a second superconductor wire (10) having an end region (14) for attachment to the second terminal (5) and an opposite end region (16); a third superconductor wire (12); and a sheet metal element (18) having a first surface (20) and a second surface (22) on an opposite side of the first surface, the first superconductor wire (8) and the second superconductor wire (10) are each attached to the first surface (20) of the sheet metal element (18) with respective opposite end regions (16) of the first superconductor wire and the second superconductor wire, the shape of the opposite end region (16) of the first superconductor wire (8) and the shape of the opposite end region (16) of the second superconductor wire (10) have a curved shape, and the third superconductor wire (12) is attached to the second surface (22) of the sheet metal element (18), the end regions (14, 16) of the third superconductor wire (12) have a curved shape and at least partially overlap the opposite end region (16) of the first superconductor wire (8) and the opposite end region (16) of the second superconductor wire (10), respectively. In this manner, a robust connector for a magnetic resonance examination apparatus is provided.

Description

Technical Field

[0001] This invention relates to the field of magnetic resonance imaging. In particular, this invention relates to the field of connectors for magnetic resonance imaging apparatus. Background Technology

[0002] Magnetic resonance imaging (MRI) devices use a main magnetic field to align the nuclear spins of atoms. This main magnetic field is generated by a superconducting static field magnet comprising several coils within a cryostat in the MRI device. In this paper, MRI devices include magnetic resonance imaging equipment primarily used for diagnostic imaging of patients, as well as nuclear magnetic resonance (NMR) devices.

[0003] To generate the main magnetic field, a current must be supplied to the static field magnet, and thus to the coil. This current can be provided by an external power supply connected to the cryostat of the magnetic resonance imaging (MRI) apparatus. To maintain the superconducting state of the static field magnet, the cryostat must maintain the temperature required for superconductivity. For common static field magnets, niobium-titanium (NbTi) superconductors operate at 4 Kelvin (K), and magnesium diboride (MgB2) superconductors operate at 20 K. This temperature is typically achieved using liquid helium as a coolant.

[0004] In particular, magnesium diboride enables it to operate in a simplified cryogenic environment because the construction of its conductive cooling coil allows it to use less liquid helium than niobium-titanium superconductors, or none at all.

[0005] To ensure the magnetic field within the recesses of the aperture formed in the cryostat is as uniform as possible, several coils electrically connected to each other must be used. These current connections between the different coils in the magnesium diboride superconducting static field magnet are a critical component because they affect residual resistance and thus the heat generated in the cryostat. Furthermore, they are mechanically more demanding than simple coil windings of magnesium diboride superconductor in the coils. One option is to make separate coils from individual wires, which in turn requires forming non-superconducting connections. The design of these connectors is critical because they introduce residual resistance, so the heat generated in the cryostat must be kept to an absolute minimum. They are also mechanically more demanding than simple coil windings of magnesium diboride superconductor in the coils.

[0006] WO2013 / 114233A1 discloses a magnetic resonance imaging system including a superconducting magnet having a first current lead and a second current lead for connection to a current ramp-change system. The magnet also includes a vacuum container penetrated by the first and second current leads. The magnet further includes a magnet circuit within the vacuum container. The magnet circuit has a first magnet circuit connection and a second magnet circuit connection. The magnet also includes a first switch between the first magnet connection and the first current lead, and a second switch between the second magnet connection and the second current lead. The magnet also includes a first shunt connected across the first switch and a second shunt connected across the second switch. Summary of the Invention

[0007] The object of this invention is to provide a robust connector for a magnetic resonance imaging (MRI) examination device.

[0008] According to the invention, this objective is achieved through the subject matter of the independent claims. Preferred embodiments of the invention are described in the dependent claims.

[0009] Therefore, according to the present invention, a connector is provided for current connection of a first terminal of a magnetic resonance imaging (MRI) device to a second terminal of the MRI device, the connector comprising: a first superconducting wire having an end region for attachment to the first terminal and an opposite end region; a second superconducting wire having an end region for attachment to the second terminal and an opposite end region; a third superconducting wire; and a metal plate element having a substantially flat first surface and a substantially flat second surface on opposite sides of the first surface, wherein the first and second superconducting wires are each attached to the substantially flat first surface of the metal plate element via their respective opposite end regions, the shapes of the opposite end regions of the first and second superconducting wires having curved shapes, and the third superconducting wire is attached to the substantially flat second surface of the metal plate element, wherein the end region of the third superconducting wire also has a curved shape and at least partially overlaps with the opposite end regions of the first and second superconducting wires, respectively. A substantially flat surface should be interpreted as including both flat and slightly curved surfaces. Basically, overlap should be interpreted as overlap to a large extent (e.g., 70%, 80%, 90%, 100%).

[0010] The connector can be used to connect an external power source to the cryostat of the magnetic resonance imaging (MRI) apparatus to supply power to the cryostat. Similarly, the connector can be used for various connections within the MRI apparatus. However, it is particularly preferred that the first and second terminals are used at the first and second coils of the MRI apparatus, respectively, such that the connector connects the first coil to the second coil at the corresponding terminals. The end regions of the first and second superconducting wires can be soldered to the first and second terminals.

[0011] According to the present invention, it has been recognized that although magnesium diboride superconductors require very little helium and are considered high-temperature superconductors operating at a superconducting temperature of 20 K, the brittleness of magnesium diboride presents challenges in establishing current connections between coils during the fabrication of magnetic resonance imaging (MRI) devices. Similarly, these connections are space-consuming in cryogenic systems because the brittleness affects the dimensions of the coil windings, and the bending radius of magnesium diboride only allows for the connection of two coils with fully helical windings.

[0012] These problems can be avoided by using the connector according to the invention. Since the first to third superconducting wires are connected to each other via a metal plate element, the first and second terminals can be connected to each other in a space-saving manner. The superconducting wires can be formed straight, and therefore applied at an angle to the metal plate element, allowing the superconductor to connect the two terminals to each other in the best possible way. Since magnesium diboride is brittle only after the reaction process is completed and can still be shaped into any desired form before that, the superconducting wires can be prefabricated into the desired shape for final assembly.

[0013] The fact that the curved end regions of the third superconductor overlap with the opposite end regions of the first and second superconductor lines respectively means that these end regions are attached to the overlapping areas on opposite sides of the metal plate element.

[0014] By using end regions with curved shapes, the contact area on the metal plate element is increased, which in turn reduces the contact resistance.

[0015] In principle, curved shapes can be designed in different ways. However, according to a preferred embodiment of the invention, the curved shape is selected from: meandering shapes, coil shapes, or combinations thereof. Compared to straight shapes, meandering shapes and coil shapes allow for longer attachments (joints) with less extension, and longer joints reduce contact resistance.

[0016] Generally, metal plate elements can be made of different materials. However, according to a preferred embodiment of the invention, the metal plate element comprises copper. Copper is an excellent conductor of heat and electricity. This means that the superconducting wires can be thermally coupled to each other to maintain the lowest possible temperature loss. At the same time, copper is easy to process and can still be manipulated in the field during the assembly of the magnetic resonance imaging (MRI) device.

[0017] Different superconductors can be used in the superconducting wire. However, according to a preferred embodiment of the invention, the first, second, and third superconducting wires comprise high-temperature superconductors. Various high-temperature superconductors can be provided for this purpose. However, according to a preferred embodiment of the invention, the high-temperature superconductor is MgB2. The advantage of using a high-temperature superconductor is that it can conduct cooling more efficiently than NbTi superconductors, for example, NbTi superconductors are preferably surrounded by liquid helium. This avoids the need to introduce liquid helium into the connector to maintain the connector at a superconducting temperature. For this purpose, the high-temperature superconductor can be in the form of high-temperature superconducting strands deposited in a metal matrix (e.g., on a strip) to form a single superconducting wire.

[0018] In principle, superconducting wires can have various shapes. However, according to a preferred embodiment of the invention, the intermediate region connecting the two end regions of the superconducting wire has a straight shape. This prevents breakage due to the brittleness of the superconducting material.

[0019] The end regions of the superconductor can be connected to the metal plate element in various ways. However, according to a preferred embodiment of the invention, the end regions of the superconductor wire attached to the metal plate element are attached to the metal plate element by soldering. Soldering the end regions to the metal plate element allows for simple and efficient assembly of the connector, which also enables field manipulation during connector insertion.

[0020] In principle, metal plate elements can be formed in various ways. However, according to a preferred embodiment of the invention, the metal plate element includes a first sub-element, a second sub-element, and a third sub-element, wherein the opposing end regions of the first superconducting line are attached to the first sub-element, the opposing end regions of the second superconducting line are attached to the second sub-element, the third superconducting line is fully attached to the third sub-element, and both the first and second sub-elements are removably attached to the third sub-element. The sub-elements are preferably designed such that the sides facing each other are flat, allowing them to contact each other as advantageously as possible. The sides of the sub-elements facing away from each other then have corresponding contacts with the respective superconducting lines. In this way, the connector can be transported in a modular form. In the field, only the end regions of the first and second superconducting lines will need to be connected to the first and second terminals using processes such as soldering. The other parts of the connector can contact each other with the sub-elements.

[0021] According to a preferred embodiment of the present invention, the metal plate element includes a first sub-element, a second sub-element, a third sub-element, and a fourth sub-element, wherein the opposite end regions of the first superconducting line are attached to the first sub-element, the opposite end regions of the second superconducting line are attached to the second sub-element, one end region of the third superconducting line is attached to the third sub-element, the opposite end regions of the third superconducting line are attached to the fourth sub-element, the first sub-element is removably attached to the third sub-element, and the second sub-element is removably attached to the fourth sub-element.

[0022] This means the connector can cover a longer distance. The middle region of the third superconducting wire no longer contacts the metal plate element. Sub-elements are used to intercept changes in connector placement orientation. Then, the distance between two widely spaced coils can be bridged using a third superconducting wire of the corresponding length.

[0023] In principle, sub-elements can be connected to each other in various ways. However, according to a preferred embodiment of the invention, the sub-elements include through holes through which screws pass to fasten the respective sub-elements to each other. Of course, in addition to screws, other fasteners suitable for connecting sub-elements to through holes can be provided.

[0024] Through holes can have different shapes. However, according to a preferred embodiment of the invention, the through hole has an elliptical or circular shape with a diameter larger than that required for the screw to pass through. This allows for slight mechanical adjustments.

[0025] The present invention also relates to a coil assembly for a magnetic resonance imaging (MRI) examination apparatus, the coil assembly comprising: a first coil having a first terminal, a second coil having a second terminal, and a connector according to any one of the preceding claims, the connector being used to connect the coils to each other at the respective terminals.

[0026] In addition, according to the present invention, a magnetic resonance imaging apparatus including the coil assembly as described above is provided. Attached Figure Description

[0027] These and other aspects of the invention will become apparent and elucidated from and with reference to the embodiments described below. Such embodiments do not necessarily represent the full scope of the invention. In the accompanying drawings: Figure 1a A front view of a connector according to a preferred embodiment of the present invention is schematically depicted; Figure 1b A rear view of a connector according to a preferred embodiment of the present invention is schematically depicted; Figure 2a A front view of a connector according to another preferred embodiment of the invention is schematically depicted; Figure 2b A rear view of a connector according to another preferred embodiment of the invention is schematically depicted; Figure 3 A connector according to a third preferred embodiment of the invention is schematically depicted; Figure 4 A coil assembly according to a preferred embodiment of the invention is schematically depicted; and Figure 5 A magnetic resonance imaging (MRI) apparatus according to a preferred embodiment of the present invention is schematically depicted. Detailed Implementation

[0028] Figure 1a A schematic front view of a connector 1 according to a preferred embodiment of the invention is shown. The connector 1 has a first superconducting line 8 and a second superconducting line 10. Each of the two superconducting lines 8 and 10 includes an end region 14 and an opposing end region 16. The first superconducting line 8 and the second superconducting line 10 extend from the end region 14 to the opposing end region 16, having a straight intermediate region 24. The end region 14 and the opposing end region 16 are meandering. The opposing end region 16 is soldered to a first flat surface 20 of a metal plate element 18.

[0029] Figure 1bA schematic rear view of a connector 1 according to a preferred embodiment of the invention is shown. A third superconducting wire 12 is arranged on a second flat surface 22 opposite to a first flat surface 20 of a metal plate element 18. Similar to the first superconducting wire 8 and the second superconducting wire 10, the third superconducting wire 12 also extends from an end region 14 to an opposite end region 16, wherein the end region 14 of the third superconducting wire 12 on the second flat surface 22 overlaps with the opposite end region 16 of the first superconducting wire 8 on the first flat surface 20. Therefore, the opposite end region 16 of the third superconducting wire 12 on the second flat surface 22 overlaps with the opposite end region 16 of the second superconducting wire 10 on the first flat surface 20. This allows current to be transmitted through the metal plate element 18 between the end regions 14, 16. However, the current is transmitted along the metal plate element 18 via the third superconducting wire 12. The overlap of the metal plate element 18 between the respective end regions 14, 16 ensures the lowest possible contact resistance in the metal plate element 18. The first superconducting line 8, the second superconducting line 10, and the third superconducting line 12 are preferably formed using magnesium diboride as a high-temperature superconductor. Furthermore, the metal plate element 18 is preferably a copper plate. The design of the connector 1 chosen here avoids exceeding the bending radius of the magnesium diboride superconductor. The straight intermediate region 24 takes into account this brittleness of the material.

[0030] Figure 2a A front view of a connector 1 according to another preferred embodiment of the invention is schematically shown. In this embodiment, the metal plate element 18 has a first sub-element 26, a second sub-element 28, and a third sub-element 30. The first sub-element 26 and the second sub-element 28 are provided with through holes 34, and the corresponding sub-element 26, 28 are connected to the third sub-element 30 via the through holes 34 using corresponding screws 36. The third sub-element 30 also has through holes 34. Opposite end regions 16 of the first superconducting wire 8 are soldered to the side of the first sub-element 26 facing away from the third sub-element 30. Opposite end regions 16 of the second superconducting wire 10 are soldered to the side of the second sub-element 28 facing away from the third sub-element 30. The sides of the sub-elements facing each other are flat to achieve the most advantageous contact.

[0031] Figure 2b A rear view of connector 1 according to another preferred embodiment of the invention is shown schematically. Similar to... Figure 1b The third superconducting line 12 is applied to the side of the third sub-element 30 away from the first sub-element 26 and the second sub-element 28. Figure 2a and Figure 2b The basic feature of the illustrated embodiment is the modular structure of connector 1. The first superconducting wire 8 is soldered to the first sub-element 26, and thus can be attached to the third sub-element 30 using screws 36. The same applies to the second superconducting wire 10 soldered to the second sub-element 28.

[0032] Figure 3 A connector according to a third preferred embodiment of the invention is schematically shown. Similar to... Figure 2a and Figure 2b In the illustrated embodiment, the first superconducting wire 8 is soldered to the first sub-element 26. The second superconducting wire 10 is soldered to the second sub-element 28. However, the first sub-element 26 and the second sub-element 28 are now screwed to the third sub-element 30 and the fourth sub-element 34, which are provided with through holes 34 with screws 36. The third sub-element 30 is screwed to the first sub-element 26, and the fourth sub-element 32 is screwed to the second sub-element 28. The third sub-element 30 and the fourth sub-element 32 are... Figure 3 While shown in an enlarged view, this is not always the case. In reality, these sub-elements 30, 32 can also be designed to correspond with the corresponding first sub-elements 26 and second sub-elements 28. The third superconducting line 12 is indicated by a dashed line in the semi-transparent view. The end region 14 of the third superconducting line 12 is soldered to the side of the third sub-element 30 facing away from the first sub-element 26. The opposite end region 16 of the third superconducting line 12 is soldered to the side of the fourth sub-element 32 facing away from the second sub-element 28. Therefore, the middle region 24 of the third superconducting line no longer has any contact with the metal plate element 18. In particular, for this embodiment of the invention, the additional spaced-apart terminals 2, 5 can be in current contact with each other.

[0033] For example, in Figure 4 This situation is illustrated here. A coil assembly according to a preferred embodiment of the invention is schematically shown. In this case, connector 1 is connected to the second terminal 5 of the second coil 6 by a first coil 3 supplied with a first terminal 2. More specifically, the end regions 14 of the first superconducting wire 8 and the second superconducting wire 10 of connector 1 are capable of making current contact with the first terminal 2 and the second terminal 5. In order to... Figure 4 and Figure 5 The terminals 2 and 5 shown are in contact, and the end regions 14 of the first superconducting line 8 and the second superconducting line 10 are welded to these terminals.

[0034] Figure 5 A preferred embodiment of the invention is schematically depicted. Figure 4 Magnetic resonance examination device 4 for coil assembly.

[0035] Although the invention has been described and illustrated in detail in the accompanying drawings and the foregoing description, such description and illustration are to be regarded as illustrative or exemplary rather than restrictive; the invention is not limited to the disclosed embodiments. Other variations of the disclosed embodiments will be understood and implemented by those skilled in the art in practicing the claimed invention by studying the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the words "a" or "an" do not exclude a plurality. The mere fact that certain measures are recited in different dependent claims does not indicate that combinations of these measures cannot be advantageously used. No reference numerals in the claims should be construed as limiting the scope. Furthermore, for clarity, not all elements in the drawings are provided with reference numerals.

Claims

1. A connector (1) for electrically connecting a first terminal (2) of a magnetic resonance imaging (MRI) device (4) to a second terminal (5) of the MRI device (4), the connector comprising: The first superconducting wire (8) has an end region (14) for attachment to the first terminal (2) and an opposite end region (16). The second superconducting wire (10) has an end region (14) for attachment to the second terminal (5) and an opposite end region (16). The third superconducting line (12), and A metal plate element (18) having a first surface (20) and a second surface (22) on the opposite side of the first surface, wherein, The first superconducting line (8) and the second superconducting line (10) are each attached to the first surface (20) of the metal plate element (18) using their respective opposite end regions (16). The shape of the opposite end region (16) of the first superconducting wire (8) and the shape of the opposite end region (16) of the second superconducting wire (10) have curved shapes, and The third superconducting line (12) is attached to the second surface (22) of the metal plate element (18), wherein each of the end regions (14, 16) of the third superconducting line (12) has a curved shape and at least partially overlaps with the opposite end region (16) of the first superconducting line (8) and the opposite end region (16) of the second superconducting line (10), respectively.

2. The connector (1) according to claim 1, wherein, The curved shape is one of the following: a meandering shape, a coil shape, or a combination thereof.

3. The connector (1) according to claim 1 or 2, wherein, The metal plate element (18) comprises copper.

4. The connector (1) according to any one of the preceding claims, wherein, The first superconducting line (8), the second superconducting line (10) and the third superconducting line (12) include high-temperature superconductors.

5. The connector (1) according to claim 4, wherein, The high-temperature superconductor is MgB2.

6. The connector (1) according to any one of the preceding claims, wherein, The middle region (24) of the superconducting lines (8, 10, 12) connecting the two end regions (14, 16) of the superconducting lines (8, 10, 12) has a straight shape.

7. The connector (1) according to any one of the preceding claims, wherein, The end regions (14, 16) of the superconducting lines (8, 10, 12) that are attached to the metal plate element (18) are attached to the metal plate element (18) by welding.

8. The connector (1) according to any one of the preceding claims, wherein, The metal plate element (18) includes a first sub-element (26), a second sub-element (28), and a third sub-element (30), wherein, The opposite end region (16) of the first superconducting line (8) is attached to the first sub-element (26). The opposite end region (16) of the second superconducting line (10) is attached to the second sub-element (28). The third superconducting line (12) is completely attached to the third sub-element (30), and Both the first sub-element (26) and the second sub-element (28) can be removably attached to the third sub-element (30).

9. A connector (1) for electrically connecting a first terminal (2) of a magnetic resonance imaging (MRI) device (4) to a second terminal (5) of the MRI device (4), the connector comprising: The first superconducting wire (8) has an end region (14) for attachment to the first terminal (2) and an opposite end region (16). The second superconducting wire (10) has an end region (14) for attachment to the second terminal (5) and an opposite end region (16). The third superconducting line (12), and Four metal plate components (18), among which, The shapes of the opposite end regions (16) of the first superconducting line (8) and the opposite end regions (16) of the second superconducting line (10) are curved, and each of the end regions (14, 16) of the third superconducting line (12) is curved. The opposite end regions (16) of the first superconducting line are attached to the first sub-element (26). The opposite end region (16) of the second superconducting line is attached to the second sub-element (28). One end region (14, 16) of the third superconducting line (12) is attached to the third sub-element (30). The opposite end region (16) of the third superconducting line (12) is attached to the fourth sub-element (32). The first sub-element (26) is removably attached to the third sub-element (30), and The second sub-element (28) is removably attached to the fourth sub-element (32) such that each end region of the end regions (14, 16) of the third superconducting line (12) at least partially overlaps with the opposite end region (16) of the first superconducting line (8) and the opposite end region (16) of the second superconducting line (10).

10. The connector (1) according to claim 8 or 9, wherein, The sub-elements (26, 28, 30, 32) include through holes (34) through which screws (36) pass to fasten the respective sub-elements (26, 28, 30, 32) to each other.

11. The connector (1) according to claim 10, wherein, The through hole (34) has an elliptical shape or a diameter larger than that required for the screw (36) to pass through.

12. The connector according to any one of the preceding claims, wherein, The end regions that overlap at least partially are essentially overlapping end regions.

13. The connector according to any one of the preceding claims, wherein, The surface of the metal plate element is substantially flat.

14. A coil assembly for a magnetic resonance imaging (MRI) examination apparatus (4), the coil assembly comprising: A first coil (3) having a first terminal (2), a second coil (6) having a second terminal (5), and a connector (1) according to any one of the preceding claims, the connector being used to connect the coils (3, 6) to each other at the respective terminals (2, 5).

15. A magnetic resonance imaging apparatus (4) having a coil assembly according to claim 14.

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