Surface wave trap of cable device, cable device and magnetic resonance equipment

Abstract

The utility model relates to a surface wave trap (20a-20b) for a cable device (16) of magnetic resonance equipment (10), which comprises at least one winding holding part (22) which is basically cylindrical and is used for holding the cable device (16) and generating a winding (24) by the cable device (16). The surface trap (20a-20b) comprises at least one capacitor device (26) on a circuit board (28) of the surface trap (20a-20b), and an adjusting bolt (30) which is supported at least partially on the winding holder (22), the circuit board (28) and the capacitor device (26) being arranged on a cover surface (32) of the winding holder (22), the circuit board (28) has a receptacle (34) for the adjusting bolt (30) such that the adjusting bolt (30) can be screwed into the cavity (36) of the winding holder (22) by means of the receptacle (34). In addition, the utility model also relates to a cable device (16) and magnetic resonance equipment (10).

Description

Technical Field

[0001] The utility model relates to a surface notch filter for a cable device of a magnetic resonance device. The cable device includes at least one substantially cylindrical winding holding part for holding the cable device and generating a winding by the cable device. The cable device includes at least one capacitor device on a circuit board of the surface notch filter and includes an adjusting bolt, and the adjusting bolt is at least partially supported on the winding holding part. In addition, the utility model also relates to a corresponding cable device and a corresponding magnetic resonance device. Background Art

[0002] In a magnetic resonance tomograph (MRT), various cables are required in the region of the transmission field of the body coil (BC), such as for receiving MR signals or sensor data or for supplying voltage. Since the cable can be constructed of a conductive material, the cable may act as an electrical antenna from a certain length, which length depends in particular on the MR (magnetic resonance) frequency. Since a non-negligible current will conduct on the cable in this case and this current may pose a potential risk to the patient, this current must be suppressed, or rather, the antenna effect of the cable must be avoided.

[0003] This is achieved by means of so-called surface notch filters, and a plurality of surface notch filters are arranged at intervals on the cable or cable bundle. In a feasible embodiment, the surface notch filter is formed by a toroidal winding of the cable itself. The winding is an inductor in principle, and a capacitor is installed in parallel with the winding. Thus, a parallel oscillating circuit is formed, which is tuned to the magnetic resonance frequency to suppress the current on the outer jacket. The cable has its own shielding layer, such as a coaxial cable or a triaxial cable, and the shielding layer of the cable itself can be used for this purpose. In the case of a cable bundle composed of a plurality of different cables, an external shielding layer must be assembled around the cable bundle, and the external shielding layer covers the entire length of the cable bundle.

[0004] Other configurations of surface notch filters are also known. For example, there is a ferrite solution, but obviously due to magnetic field reasons, the ferrite solution cannot be used in a magnetic resonance tomograph. Compared with the above-described configuration, other non-magnetic configurations have larger dimensions to obtain the same shielding effect. Since the introduced structural solution can be implemented very compactly, this type of structure is usually installed in the inlet line of a local coil, and the cable of the local coil must be guided on or beside the patient. Summary of the Utility Model

[0005] The technical problem to be solved by the utility model is to provide a surface notch filter, a cable device and a magnetic resonance device, whereby the surface notch filter can be provided with a reduced structural space.

[0006] This technical problem is solved by a surface notch filter, a cable device, and a magnetic resonance apparatus. Advantageous design forms are given in the embodiments.

[0007] The utility model relates to a surface notch filter for a cable device of a magnetic resonance apparatus. The surface notch filter includes at least one substantially cylindrical winding holder for holding the cable device and generating a winding by the cable device, and the surface notch filter includes at least one capacitor device on a circuit board of the surface notch filter and includes an adjustment bolt that is at least partially supported on the winding holder.

[0008] It is hereby provided that the circuit board together with the capacitor device is arranged on the cover surface of the winding holder, wherein the circuit board has a receiving portion for the adjustment bolt so that the adjustment bolt can be screwed into the cavity of the winding holder by means of this receiving portion.

[0009] Thereby, in particular, a combined arrangement for space-saving fine adjustment in the surface notch filter can be achieved by means of the adjustment bolt. Thereby, in particular, a surface notch filter with reduced structural space can be provided.

[0010] The technical problem to be solved in the surface notch filter is that the oscillating circuit of the surface notch filter is very narrowband. This means that the harmonic frequencies must be precisely matched. The inductance formed by the winding is fixed. The capacitance or capacitors used can be designed in different combinations to adjust the resonance frequency. With component changes or other changes, the resonance frequency fluctuates in the same inductance facility. In this case, a trimmer capacitor cannot be used for fine adjustment because in this case a high voltage and / or a higher current drop is formed by this capacitor, while the trimmer capacitor in a small structure does not bring higher voltage and / or current performance. Therefore, one or more bolts are installed in the winding. The bolts can also be called adjustment bolts and are made of a conductive and magnetic material. The bolts interact with the oscillating circuit and thereby finely adjust the resonance frequency accordingly.

[0011] The adjustment bolt in turn requires a guiding portion in the form of a threaded portion or some kind of channel into which the adjustment bolt can be screwed. Since the surface notch filter should be constructed as small as possible, the holder in the prior art is only implemented to be as long as the winding. Usually, the adjustment bolt can be embedded in this holder. The problem here is that the adjustment bolt does not interact with the oscillating circuit only by the part of the adjustment bolt that is directly inside the winding, but already interacts with the oscillating circuit due to the magnetic field of the winding before the winding. When the winding body into which the adjustment bolt is embedded starts to be wound, the adjustment bolt must be embedded in the holder to a certain extent for firm fixation. However, this means that the interaction between the adjustment bolt and the oscillating return current may already be too strong, and an accurate resonance frequency can no longer be set using the adjustment bolt.

[0012] Thus, in the prior art, the winding body has been implemented to be relatively long throughout, and the adjusting bolt could also be fixed prior to the winding at the above-mentioned position. However, this makes the surface wave filter unnecessarily long, and when the surface wave filter is applied in the coil channel, a relatively large bending radius is formed thereby, reducing the flexibility of the cable. As a result, the length of the winding body, the circuit board connected thereto, and the components are unnecessarily large.

[0013] To solve this problem, it is stipulated that the capacitor device required for the resonant circuit is installed on the circuit board, and the circuit board is soldered to the cable device itself. According to the present invention, the circuit board extends in the longitudinal direction of the winding, particularly before and / or after the winding. Similarly, the circuit board is used to fixedly mount the adjusting bolt at a certain distance from the winding itself. For this purpose, the circuit board is provided with an opening or a receiving portion, which is configured flush with the inner opening of the winding holding portion, and the adjusting bolt is generally fixedly held in the inner opening. The opening or the receiving portion of the circuit board is designed to form a threaded portion for the bolt, or the opening or the receiving portion has a diameter such that a threaded portion is formed by screwing in the adjusting bolt. Thus, the adjusting bolt can also be fixed at a relatively large distance from the winding, thereby broadening the adjustment range of the resonant frequency.

[0014] Thus, the general difference compared with the prior art is particularly that the required circuit board also serves as a capacitor support and as an extension of the bolt guide / winding body for fine-tuning the surface wave filter. As a result, the structure of the surface wave filter is reduced or kept as small as possible. The adjusting bolt is also fixed beside the guide portion at the same time.

[0015] In an alternative embodiment, the winding holding portion may further have an extended area, which can be guided into the recess of the circuit board. This extended area can be used as a bolt guide for the adjusting bolt. The extended area can end flush with the circuit board, or can also be guided inward through the circuit board.

[0016] According to an advantageous design, the receiving portion is at least partially configured for the threaded portion of the adjusting bolt. In other words, the receiving portion already has a thread to correspondingly hold or fix the bolt, and thereby achieve a threaded connection in the cavity of the winding holding portion. The advantage is that, for example, no debris is formed when the adjusting bolt is screwed in, and the debris may further adversely affect the magnetic field. Thus, it is particularly stipulated that the circuit board has a threaded portion at least partially in the receiving portion, whereby the adjusting bolt can be further screwed into the cavity.

[0017] Furthermore, it is advantageous that the adjusting bolt is configured as a tapped bolt. Thereby, the bolt can in particular be manufactured as a tapped bolt and thereby, for example, provide a receiving portion without a thread. By screwing the tapped bolt into the receiving portion, a threaded portion is formed in the receiving portion, whereby the adjusting bolt can be reliably held in the circuit board. Thereby, fixation can already be achieved by fewer screwing operations, thus enabling particularly precise fine adjustment of the surface wave filter.

[0018] Equally advantageously, at least one turn of the winding is at least partially configured in the circuit board. The winding in particular has a plurality of turns extending along the winding holding portion. The winding is in particular arranged on the winding holding portion when viewed longitudinally. It can be provided that at least a first winding or also a second or third winding is already implemented in the circuit board. Thereby, reliable contact with the winding can be provided by the circuit board. Furthermore, the advantage also lies in that fine adjustment of the magnetic field for the winding can already be achieved by screwing the adjusting bolt into the circuit board. Thereby, further reduction of the structural space of the surface wave filter can be achieved.

[0019] It is also considered advantageous to configure at least one soldering point on the circuit board for soldering the circuit board to the cable device. In particular, it is necessary that the cable device is electrically connected to the circuit board, in particular to the capacitor device or to the capacitor, thereby forming an oscillating circuit. By providing the soldering point on the circuit board, an electrical oscillating circuit can be reliably formed and at the same time the structural space can be reduced.

[0020] Furthermore, it is also considered advantageous that the winding holding portion is configured in a screw-like manner. In particular, the winding holding portion is configured in a screw-like manner, for example, along the outer jacket surface of the winding holding portion in terms of its longitudinal shape, or has a screw-like receiving portion into which the cable device can in turn be guided. Thereby, an inductance can be reliably provided, which is necessary for the oscillating circuit. Thereby, the inductance can be adjusted very precisely by the winding holding portion.

[0021] Equally advantageously, another circuit board is arranged on another cover surface of the winding holding portion opposite the cover surface, which has another receiving portion for receiving another adjusting bolt. Here, in particular, the other circuit board, the other receiving portion and the other adjusting bolt are configured substantially identically to the circuit board, the receiving portion and the adjusting bolt. Thereby, in particular, the circuit board and the other circuit board can be provided opposite each other, so that corresponding circuit boards with adjusting bolts can be provided on the two cover surfaces of the substantially cylindrical winding holding portion. Thereby, fine adjustment of the resonance frequency can be implemented on both sides.

[0022] It is also considered advantageous that the cavity has at least locally a diameter smaller than that of the adjusting bolt. In other words, it is particularly provided that the adjusting bolt can also be screwed at least locally into the cavity and thus fixed by the fixing part. Thereby, it can be achieved that the adjusting bolt is fixed correspondingly by the cavity or by its outer wall. Thereby, a displacement of the adjusting bolt and thus a displacement of the resonance frequency are reliably avoided.

[0023] Equally advantageously, the adjusting bolt is tapered at a first end arranged in the direction towards the cavity. By the tapered shape, reliable screwing of the adjusting bolt into the winding body and into the circuit board can be achieved. In addition, by the tapered shape, the magnetic field can be very finely influenced from the beginning, so that a particularly precise adjustment of the resonance frequency can be made.

[0024] Equally advantageously, the cavity has three connecting bars extending in its longitudinal direction, and a receiving cavity for the adjusting bolt is formed between the connecting bars. In particular, the connecting bars extend from one cover surface of the winding fixing part to another cover surface of the winding fixing part. The connecting bar can in turn have corresponding gaps between the connecting bars. The connecting bars can be arranged substantially in a star shape. Then it can be provided that, for example, corresponding contact surfaces for the adjusting bolt are provided on the surface of the connecting bar generally facing the center of the cylinder of the winding fixing part, and thus a thread part is formed on this surface. In other words, this surface of the connecting bar serves as a fixing part for the adjusting bolt in the screwed-in state. However, due to the gaps between the connecting bars, the material requirement can also be reduced, and thus a surface wave filter can be realized with less material cost. For example, the connecting bars can be constructed at an angle of 120° to each other.

[0025] Another advantageous design provides that the cable device is constructed as a coaxial cable or a triaxial cable. In this case, there is no need to provide a corresponding outer jacket for the cable device. The outer jacket already exists in the coaxial cable or triaxial cable. If the cable device is not constructed as a coaxial cable or a triaxial cable, for example, in the form of a cable bundle, it is necessary to construct a shielding element around the cable device itself.

[0026] Another advantageous design provides that the adjusting bolt is constructed as a countersunk screw. In particular, the countersunk screw has a corresponding depression on the surface facing away from the cavity, so that it can be screwed into the circuit board or the cavity, for example, with a tool. By being constructed as a countersunk screw, this particularly means that the diameter of the bolt extends substantially over the entire longitudinal extension region, so that the entire length of the countersunk screw can be used to achieve fine adjustment by the screwing process, for example, without a stop point.

[0027] Another advantageous design provides that the adjusting bolt is constructed of a conductive material. The adjusting bolt can for example be constructed of steel, brass, copper or other conductive materials. The advantage is that a reliable adjustment of the resonance frequency can be carried out by means of the adjusting bolt.

[0028] Another aspect of the present utility model relates to a cable device for a magnetic resonance apparatus, which comprises at least one surface notch filter according to the foregoing aspect. The cable device can in particular have a plurality of surface notch filters. Accordingly, the surface notch filters can be installed at the spacings corresponding to the foregoing in order to avoid an impermissible antenna effect of the cable device. Here, the cable device is constructed as a coaxial cable or a triaxial cable. It is also feasible that the cable device has a plurality of single cables, which are subsequently shielded by the shielding element of the cable device. Thereby, the surface notch filters can be used for a variety of different cable devices.

[0029] Likewise, the present utility model also relates to a magnetic resonance apparatus having at least one cable device according to the foregoing aspect.

[0030] A magnetic resonance tomography (MRI) apparatus is an imaging apparatus that uses a strong external magnetic field to orient the nuclear spins of the object to be examined and makes them precess by applying high-frequency excitation pulses, thereby achieving the corresponding orientation. The precession or transition of the spins from the excited state to a state with lower energy generates an electromagnetic alternating field, and the magnetic resonance signal can be detected by a receiving antenna.

[0031] With the help of a magnetic gradient field, position encoding can be manifested on the signal, and this position encoding subsequently allows the obtained signal to be assigned to the volume elements of the object to be examined. The received signal can then be evaluated in order to provide, for example, an image of the object to be examined.

[0032] Unless otherwise specified, the connection of two electronic or electrical components can be understood as an electrical connection existing between the components or an electrical connection being established by operating one or more switching elements (circuit / arrangement / device). Unless otherwise specified, the components can in particular be directly or indirectly connected to each other. Here, a direct connection can be understood as meaning that, apart from optionally one or more switching elements, no other electrical or electronic components are arranged between the components; while an indirect connection can be understood as meaning that, apart from optionally one or more switching elements, one or more additional electrical or electronic components, such as resistors, capacitors, coils, etc., are arranged between the components.

[0033] Other features of the present utility model are derived from the claims, the drawings and the description of the drawings. The features and combinations of features mentioned above in the description and the features and combinations of features mentioned and / or shown in the following description of the drawings can be included in the present utility model not only in the combinations given respectively, but also in other different combinations. In particular, embodiments and combinations of features that do not have all the features of the original claims can also be included in the present utility model. In addition, embodiments and combinations of features that go beyond or deviate from the combinations of features set forth in the reference relationships of the claims can also be included in the present utility model. Description of the Drawings

[0034] In the drawings:

[0035] Figure 1 A schematic block diagram showing an embodiment of a magnetic resonance device, including an embodiment of a cable device with an embodiment of a surface notch filter;

[0036] Figure 2 A schematic cross-sectional view showing an embodiment of a surface notch filter;

[0037] Figure 3 A schematic perspective view showing an embodiment of a surface notch filter; and

[0038] Figure 4 Another schematic cross-sectional view showing an embodiment of a surface notch filter.

[0039] The present utility model will be explained in more detail below with the aid of specific embodiments and the accompanying schematic diagrams. In the drawings, identical or functionally identical elements may be provided with the same reference numerals. Identical or functionally identical elements do not necessarily have to be repeatedly described with respect to different figures. Detailed Description of the Embodiments

[0040] Figure 1 A schematic block diagram showing an embodiment of a magnetic resonance device 10 is shown. In this embodiment, the magnetic resonance device 10 has a magnetic field generating device 12. The magnetic field generating device 12 shows a cylindrical cavity in which, for example, a platform 14 for a patient is provided. It can be provided here that, for example, a cable device 16 must be arranged at the patient, and the cable device 16 can in turn be connected, for example, to an electronic computing device 18. In order to prevent the corresponding antenna effect of the cable device 16, the cable device 16 has three surface notch filters 20a, 20b, 20c in this embodiment. The surface notch filters 20a, 20b, 20c are arranged at a given or predefined distance from each other in this embodiment, so that the antenna effect of the cable device 16 can be prevented. Obviously, more than three or fewer than three surface notch filters 20a, 20b, 20c can also be constructed on the cable device 16.

[0041] Figure 2 Shows a schematic cross-sectional view according to an embodiment of surface filters 20a, 20b, 20c. Hereinafter, only the surface filter 20a will be described in detail among the surface filters 20a, 20b, 20c. This description clearly also applies equally to the other surface filters 20a, 20b, 20c.

[0042] The surface filter 20a for the cable device 16 according to the present utility model has at least one substantially cylindrical winding holding part 22, which is purely schematically shown in this embodiment, however, it will be further described in Figure 3 and Figure 4 in more detail.

[0043] The winding holding part 22 is configured to hold the cable device 16 and is configured to generate a winding 24 through the cable device 16. In addition, the surface filter 20 also has a capacitor device 26, which can be constructed, for example, by a plurality of individual capacitors. Here, the capacitor device 26 is arranged on a circuit board 28. In addition, the surface filter 20 also has an adjustment bolt 30, which is at least partially supported on the winding holding part 22.

[0044] Here it is stipulated that the circuit board 28 together with the capacitor device 26 is arranged on the cover surface 32 of the winding holding part 22, wherein the circuit board 28 has a receiving part 34 for the adjustment bolt 30, so that the adjustment bolt 30 can be screwed into the cavity 36 of the winding holding part 22 by means of this receiving part 34.

[0045] This especially shows that in order to be able to construct a resonant circuit accordingly, the capacitor device 26 is required. The capacitor device 26 is installed on the circuit board 28 here, and the circuit board is then soldered to the cable device 16. In an embodiment according to the present utility model, the circuit board 28 is arranged before and / or after the winding holding part 22 along the longitudinal direction of the winding 24 as Figure 3 shown. Similarly, the circuit board 28 is also used to fixedly mount the adjustment bolt 30 at a certain distance from the winding 24 itself. For this purpose, the circuit board 28 provides a receiving part 34, which is constructed flush with the internal opening of the winding holding part 22, especially in the cavity 36, and the adjustment bolt 30 is generally completely held in the internal opening. The receiving part 34 of the circuit board 28 is designed to have a threaded part 30 for the bolt, or the opening or receiving part has a diameter so that a threaded part is formed by screwing in the adjustment bolt 30, and the adjustment bolt 30 is especially self-tapping. Thus, the adjustment bolt 30 can also be fixed at a relatively large distance from the winding 24, thereby broadening the adjustment range of the resonant frequency.

[0046] Figure 3Shows a schematic perspective view according to an embodiment of the surface filter 20a. In this embodiment, in particular, it is shown that the surface filter 20a can have a plurality of capacitors. In addition, in Figure 3 the receiving portion 34 is also shown in detail and thus the adjusting bolt 30 is missing. Figure 3 In particular, it is shown that, for example, a soldering point 38 can be provided to solder the circuit board 28 to the cable device 16. In addition, Figure 3 in particular, it is shown that the winding holding portion 22 is generally constructed in a screw shape. It can also be provided that, opposite the cover surface 32, another circuit board 42 is provided on another cover surface 40, which has another receiving portion 44 for receiving another adjusting bolt 46 ( Figure 4 ). In particular, another capacitor device 48 can be provided on the other circuit board 42.

[0047] Figure 4 Shows another schematic cross-sectional view according to an embodiment of the surface filter 20a. In this embodiment, two adjusting bolts 30, 46 are provided on the circuit boards 28, 42. Figure 4 In particular, it is shown that the cavity 36 at least partially has a diameter smaller than the diameter of the adjusting bolt 30. In addition, Figure 4 it is shown that the adjusting bolt 30 is tapered at a first end disposed in the direction toward the cavity 36. At a second end 52 constructed in particular opposite the first end 50, the adjusting bolt 30 can, for example, have a tool receiving portion 54 to be screwed into the circuit board 38, for example.

[0048] In addition Figure 4 it is shown that the cavity 36 has three connecting bars 56 extending in its extending direction, wherein a receiving cavity for the adjusting bolt 30 is constructed between the connecting bars 56. The connecting bars 56 can, in particular, be spaced from each other at an interval of 120° for example. A gap can also be constructed between each of the connecting bars 56, whereby material savings can be achieved. The surface 58 of the connecting bar 56 can, for example, come into contact with the adjusting bolt 30, or provide a thread portion for the adjusting bolt 30.

[0049] In addition Figure 4 it is shown that the adjusting bolt 30 is particularly constructed as a countersunk screw. In addition, the adjusting bolt 30 is constructed of a conductive material.

[0050] In particular, in order to, for example, be able to further shorten the winding holding portion 22, the winding 24, in particular, for example, at least one first turn can also be screwed into the circuit board 28, so that the circuit board 28 functions as the "last wall" of this turn. This is feasible because the circuit board 28 undertakes the aforementioned guiding and fixing functions of the adjusting bolt. If the adjusting bolt 30 is thus screwed into the conductor plate or the circuit board 28 in a self-tapping manner, a force for fixing the adjusting bolt 30 is generated in the conductor plate material.

Claims

1. A surface wave trap (20a - 20b) for a cable device (16) of a magnetic resonance apparatus (10), the surface wave trap comprising at least one substantially cylindrical winding holder (22) for holding the cable device (16) and generating a winding (24) by the cable device (16), and the surface wave trap comprising at least one capacitor device (26) on a circuit board (28) of the surface wave trap (20a - 20b), and comprising an adjusting bolt (30), the adjusting bolt being at least partially supported on the winding holder (22). Characterized in that the circuit board (28) together with the capacitor device (26) is arranged on a cover surface (32) of the winding holder (22), wherein the circuit board (28) has a receiving portion (34) for the adjusting bolt (30) such that the adjusting bolt (30) can be screwed into a cavity (36) of the winding holder (22) by means of the receiving portion (34).

2. The surface wave trap (20a - 20b) according to claim 1, characterized in that the receiving portion (34) is at least partially configured as a threaded portion for the adjusting bolt (30).

3. The surface wave trap (20a - 20b) according to claim 1 or 2, characterized in that the adjusting bolt (30) is configured as a tapping bolt.

4. The surface wave trap (20a - 20b) according to claim 1, characterized in that at least one turn of the winding (24) is at least partially configured in the circuit board (28).

5. The surface wave trap (20a - 20b) according to claim 1, characterized in that at least one soldering point (38) is configured on the circuit board (28) for soldering the circuit board (28) to the cable device (16).

6. The surface wave trap (20a - 20b) according to claim 1, characterized in that the winding holder (22) is configured in a screw-like manner.

7. The surface wave trap (20a - 20b) according to claim 1, characterized in that opposite to the cover surface (32), another circuit board is arranged on another cover surface of the winding holder (22), which has another receiving portion for receiving another adjusting bolt.

8. The surface wave trap (20a - 20b) according to claim 1, characterized in that the cavity (36) at least partially has a diameter smaller than the diameter of the adjusting bolt (30).

9. The surface wave trap (20a - 20b) according to claim 1, characterized in that the adjusting bolt (30) is configured in a conical shape at a first end arranged in the direction towards the cavity (36).

10. The surface wave trap (20a - 20b) according to claim 1, characterized in that the cavity (36) has three connecting bars (56) extending in its extending direction, and a receiving cavity for the adjusting bolt (30) is configured between the connecting bars (56).

11. The surface wave trap (20a - 20b) according to claim 1, characterized in that The cable device (16) is configured as a coaxial cable or a triaxial cable.

12. The surface trap (20a - 20b) according to claim 1, characterized in that the adjusting bolt (30) is configured as a countersunk screw.

13. The surface trap (20a - 20b) according to claim 1, characterized in that the adjusting bolt (30) is made of a conductive material.

14. A cable device (16) for a magnetic resonance device (10), characterized in that, It includes at least one surface trap (20a - 20b) according to any one of the above claims 1 to 13.

15. A magnetic resonance device (10), characterized in that, It includes the cable device (16) according to claim 14.

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