Radio frequency cable for magnetic resonance equipment and magnetic resonance equipment

Abstract

The utility model provides a radio frequency cable for magnetic resonance equipment and the magnetic resonance equipment. The radio frequency cable comprises a cable main body; the outer sheath is arranged outside the cable main body in a sleeving manner; the wave trap units are arranged between the outer sheath and the cable main body and are arranged at intervals along the axial direction of the cable main body; and any two adjacent wave trap units are separated by the insulating part. The magnetic resonance equipment comprises a main magnet, a gradient system and a radio frequency system, wherein the radio frequency system comprises a radio frequency generator, a radio frequency receiver, a radio frequency coil and a radio frequency cable.

Description

Technical Field

[0001] This specification relates to the medical field, and particularly to a radio frequency cable for a magnetic resonance device and a magnetic resonance device. Background Art

[0002] Magnetic resonance imaging (MR) systems can non-invasively obtain images of any tomogram of various parts of the human body for doctors to diagnose diseased parts. During nuclear magnetic resonance scanning, when the volume transmit coil (VTC) emits a high power, a large common-mode current will be generated on the cable of the local coil. This common-mode current will seriously affect the local radio frequency field (B1), thereby affecting the imaging quality. Therefore, in order to suppress this common-mode current, a special device - a trap needs to be installed on the cable of the local coil. With the progress of technology, the number of units of the receiving coil of magnetic resonance devices is increasing continuously, which leads to the radio frequency cable becoming thicker and thicker. Designing a trap on the radio frequency cable will undoubtedly further increase the diameter of the radio frequency cable, which brings many challenges to the design of the trap.

[0003] The trap in the related technology winds the transmission cable into a spiral shape, with a shielding cover sleeved outside. One end of the shielding cover is directly welded to the cable, and the other end is connected together through a tuning capacitor. This kind of trap has a large inductance value, so it has a good effect on suppressing common-mode current and generates little heat. However, the disadvantages are large volume, heavy weight, increased loss of the internal radio frequency line and affecting the total phase distance, and as the cable becomes thicker, the diameter of the spiral winding becomes larger and larger, resulting in the trap having an increasingly large volume and an increasingly heavy weight.

[0004] Therefore, how to design a radio frequency cable with a smaller volume, weight and heat generation and better bending performance without reducing the effect of suppressing common-mode current has become a problem to be solved. Summary of the Utility Model

[0005] One aspect of the present utility model provides a radio frequency cable for a magnetic resonance device, characterized in that the radio frequency cable includes: a cable main body; an outer sheath sleeved outside the cable main body; a plurality of trap units disposed between the outer sheath and the cable main body and spaced along the axial direction of the cable main body; and an insulating member, and any two adjacent trap units are separated by the insulating member.

[0006] In some embodiments, the insulating member is a flexible insulating member, and the outer sheath is a flexible outer sheath.

[0007] In some embodiments, the notch filter unit includes: a first coil configured as an annular spiral; a second coil configured as an annular spiral; the first coil and the second coil are provided with breaks, and capacitors are provided on both the first coil and the second coil; the winding directions of the first coil and the second coil are opposite or reverse, the first coil and the second coil are overlapped and placed, and a first channel is formed inside the first coil and the second coil, and the cable body is allowed to pass through the first channel.

[0008] In some embodiments, the notch filter unit includes: an inner sleeve sleeved outside the cable body; an outer sleeve sleeved outside the inner sleeve; a first capacitor, one end of the first capacitor is electrically connected to the inner sleeve, and the other end is electrically connected to the outer sleeve.

[0009] In some embodiments, the notch filter unit further includes a circuit board, the circuit board is annular, the inner ring of the circuit board is connected to one end of the inner sleeve, and the outer ring of the circuit board is connected to one end of the outer sleeve; the first capacitor is arranged on the circuit board.

[0010] In some embodiments, the outer sleeve is provided with a plurality of through holes, the plurality of through holes are formed into multiple groups, and each group of through holes is arranged along the circumferential direction of the outer sleeve, the multiple groups of through holes are arranged at intervals along the axial direction of the outer sleeve, and adjacent two groups of through holes are arranged staggeredly.

[0011] In some embodiments, the RF cable further includes an end connection assembly, the end connection assembly includes a connector and a housing, the connector connects the cable body, the housing is connected to the connector and covers the connector.

[0012] In some embodiments, the connector includes a second channel and a positioning wire, the cable body includes a signal transmission line and a tensile wire, the positioning wire is connected to the tensile wire, and the signal transmission line passes through the second channel.

[0013] One aspect of the present invention also provides a magnetic resonance device, the magnetic resonance device includes: a scanner forming a scanning cavity capable of accommodating a detection object; a hospital bed coupled to the scanner, the hospital bed can carry the detection object and a coil plug is provided on the hospital bed; a local coil that can be placed on the body surface of the detection object and can enter the scanning cavity with the detection object; an RF cable connecting the coil plug and the local coil; the RF cable includes: a cable body; an outer sheath sleeved outside the cable body; a plurality of notch filter units provided between the outer sheath and the cable body and arranged at intervals along the axial direction of the cable body; an insulating member, and any two adjacent notch filter units are separated by the insulating member.

[0014] In some embodiments, the notch filter unit includes: an inner sleeve, sleeved outside the cable body; an outer sleeve, sleeved outside the inner sleeve; an annular metal sheet is arranged at one end of the inner sleeve to connect the outer sleeve; a circuit board is arranged at the other end of the inner sleeve, and a first capacitor is arranged on the circuit board to connect the outer sleeve.

[0015] The beneficial effects brought by the above-mentioned utility model content include but are not limited to: (1) By serially arranging a plurality of notch filter units on the RF cable, the RF cable has better common-mode rejection ability; (2) By arranging an insulating member between two adjacent notch filter units, it is possible to prevent a short-circuit phenomenon from occurring between two adjacent notch filter units. At the same time, it is also possible to disperse the energy in a plurality of notch filter units to reduce the heat generation of a single notch filter unit and ensure the suppression effect on the common-mode current. Moreover, even if an individual notch filter unit is damaged, it will not affect the suppression effect on the common-mode current. Description of the Drawings

[0016] Figure 1 is a schematic structural diagram of a traditional cable notch filter shown in some embodiments of this specification;

[0017] Figure 2 is a schematic structural diagram of a magnetic resonance device shown in some embodiments of this specification;

[0018] Figure 3 is a schematic structural diagram of an RF cable shown in some embodiments of this specification;

[0019] Figure 4 is a schematic structural diagram of a notch filter unit shown in some embodiments of this specification;

[0020] Figure 5A is a schematic diagram of the notch filter unit sleeved on the cable body shown in some embodiments of this specification;

[0021] Figure 5B is a schematic diagram of a plurality of notch filter units sleeved on the cable body shown in some embodiments of this specification;

[0022] Figure 6A is a schematic structural diagram of the outer sleeve shown in some embodiments of this specification;

[0023] Figure 6B is a side view schematic diagram of the outer sleeve shown in some embodiments of this specification;

[0024] Figure 7 is a schematic structural diagram of a notch filter unit shown in some other embodiments of this specification;

[0025] Figure 8A It is a schematic diagram of a notch filter unit sleeved on a cable body shown in some other embodiments of this specification;

[0026] Figure 8B It is a schematic diagram of a plurality of notch filter units sleeved on a cable body shown in some other embodiments of this specification;

[0027] Figure 9 It is another schematic diagram of a radio frequency cable shown in some embodiments of this specification;

[0028] Figure 10A It is a schematic diagram of an end connection assembly shown in some embodiments of this specification;

[0029] Figure 10B It is a connection schematic diagram of an end connection assembly shown in some embodiments of this specification.

[0030] Explanation of reference numerals in the drawings: 110, radio frequency cable; 120, shielding cover; 130, tuning capacitor; 140, winding inductor; 200, magnetic resonance device; 210, scanner; 220, hospital bed; 230, local coil; 240, radio frequency cable; 211, main magnet; 212, gradient system; 213, radio frequency system; 221, coil plug; 310, cable body; 320, notch filter unit; 330, insulating part; 340, outer sheath; 321, outer sleeve; 322, inner sleeve; 323, first capacitor; 324, circuit board; 325, annular metal sheet; 326, first coil; 327, second coil; 328, break; 329, second capacitor; 350, end connection assembly; 351, connecting part; 352, outer shell; 353, positioning wire; 600, through hole. Detailed implementation manners

[0031] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as "center", "length", "axial direction", "radial direction", "circumferential direction", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0032] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0033] In the present utility model, unless otherwise clearly defined and limited, terms such as "installation", "connection", "linkage", "fixation" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral one; it may be a mechanical connection or an electrical connection; it may be a direct connection or an indirect connection through an intermediate medium, and it may be the internal communication between two components or the interaction relationship between two components, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0034] During the nuclear magnetic resonance scanning process, when the emission power of the volume transmit coil is relatively high, a large common-mode current will be generated on the RF cable of the local coil. In order to suppress this common-mode current, it is necessary to design a notch filter on the RF cable of the local coil. With the progress of technology, the number of units of the receive coil of the magnetic resonance device is increasing continuously, which results in the RF cable becoming thicker and thicker. And designing a notch filter on the RF cable will undoubtedly further increase the diameter of the RF cable, which brings many challenges to the design of the notch filter.

[0035] In some embodiments, various types of notch filters can be adopted on the RF cable to suppress the large common-mode current generated on the RF cable of the local coil.

[0036] The first type of notch filter is a cable trap, and the specific structure is as Figure 1 shown. The cable trap winds the RF cable 110 into a spiral shape. A winding inductor 140 is arranged on the spiral RF cable 110, and a shielding cover 120 is sleeved outside. One end of the shielding cover 120 is directly welded to the RF cable 110, and the other end is connected to the tuning capacitor 130. Since the inductance value of this type of cable trap is relatively large, the effect of suppressing the common-mode current is good and the heat generation is small. However, the disadvantages are that it has a large volume, heavy weight, increases the loss of the internal RF cable and affects the total phase distance. As the cable becomes thicker, the diameter of the spiral winding becomes larger and larger, and the winding operability decreases.

[0037] Another type of notch filter is a floating trap. The floating trap does not need to be connected to the cable and is completely detachable, and can be easily installed on any cable without affecting any coil parameters. However, the disadvantages are that the inductance is small and the heat generation is serious. And the effect of suppressing the common-mode current is affected by the outer diameter, and the larger the outer diameter, the better the effect. Therefore, to obtain a good common-mode suppression effect, it is necessary to increase the volume of the floating trap, and its weight also becomes heavier.

[0038] To simultaneously meet the design requirements of common-mode rejection and miniaturization, some embodiments of this specification propose a radio frequency cable for a magnetic resonance device, which adopts a brand-new miniaturized detachable notch filter structure, having the advantages of small size, light weight, low heat generation, easy debugging, and easy maintenance. This notch filter structure enables the radio frequency cable to have a smaller maximum outer diameter and better bendability. At the same time, it can effectively suppress the common-mode current on the coaxial cable, thereby reducing the impact on the local radio frequency field.

[0039] Some embodiments of this specification provide a magnetic resonance device. Figure 2 It is a schematic structural diagram of the magnetic resonance device shown in some embodiments of this specification.

[0040] The magnetic resonance device 200 can transmit electromagnetic pulse signals into the imaging space, form a static magnetic field in the imaging space to perform scanning to obtain magnetic resonance signals, and reconstruct images based on the magnetic resonance signals.

[0041] The magnetic resonance device 200 can be used for detecting and treating a detection object. Among them, the detection object can include biological objects (such as the human body, animals, etc.), non-biological objects (such as phantoms), etc. In some other embodiments, the detection object can also include specific parts, organs, and / or tissues of a patient. For example, the detection object can include the head, chest, legs, etc. or any combination thereof, which is not limited herein. In some embodiments, the detection object can be specific parts, organs, and / or tissues of a patient and other organs and / or tissues within a certain range around them.

[0042] As Figure 2 shown, the magnetic resonance device 200 includes a scanner 210, a hospital bed 220, a local coil 230, and a radio frequency cable 240.

[0043] The scanner 210 forms a scanning cavity capable of accommodating the detection object. The scanner 210 can include a main magnet 211, a gradient system 212, and a radio frequency system 213.

[0044] The main magnet 211 is a component in the scanner 210 that generates a magnetic field. For example, the main magnet 211 can be a toroidal superconducting magnet installed in a toroidal vacuum container. The superconducting magnet defines a cylindrical space around the detection object and generates a constant main magnetic field. The main magnet 211 can include a superconducting coil and a cooling system. The superconducting coil is made of superconducting material, which has a low resistance and a high current-carrying capacity. The cooling system is used to cool the superconducting coil to a low temperature state to make it in a superconducting state.

[0045] The gradient system 212 is a system in the scanner 210 that provides three-dimensional spatial positioning for magnetic resonance imaging. The gradient system 212 for imaging can be composed of three gradient coils in the X, Y, and Z directions. The gradient system 212 may include gradient coils, a gradient controller, a digital-to-analog converter, a gradient amplifier, and a gradient cooling system, etc.

[0046] The radio frequency system 213 is a system in the scanner 210 that excites the detection site and collects magnetic resonance signals.

[0047] In some embodiments, the radio frequency system 213 is capable of transmitting radio frequency pulses so that the magnetized protons in the detected object absorb energy and resonate. The radio frequency system 213 includes a radio frequency generator ( Figure 2 (not shown), a radio frequency power amplifier connected to the radio frequency generator ( Figure 2 (not shown), and a body transmit coil connected to the radio frequency power amplifier ( Figure 2 (not shown).

[0048] The radio frequency generator is used to generate radio frequency (RF) pulses and transmit them to the detected object through the transmit coil to excite the hydrogen nuclei in the detected object to generate magnetic resonance signals. The radio frequency power amplifier is used to amplify the power of the radio frequency signal. The body transmit coil is used to transmit excitation pulses and establish a radio frequency field.

[0049] In some embodiments, the radio frequency system 213 is also capable of generating magnetic resonance signals during the relaxation process and receiving the magnetic resonance signals. The radio frequency system 213 further includes a receive coil channel selector ( Figure 2 (not shown), a radio frequency receiver ( Figure 2 (not shown).

[0050] The receive coil channel selector is used to select the channel for the magnetic resonance signal to enter the radio frequency receiver. The amplified magnetic resonance signal passes through the receive coil channel selector. A switch array is provided in the receive coil channel selector, and the switch array can selectively allow a part of the magnetic resonance signals output from the output lines of each local coil to pass through and enter the radio frequency receiver.

[0051] The radio frequency receiver is used to collect magnetic resonance signals and process the collected magnetic resonance signals. For example, the collected magnetic resonance signals can be amplified, then digitized and further processed.

[0052] The hospital bed 220 is coupled to the scanner 210. The hospital bed 220 can carry the detected object and a coil plug 221 is provided on the hospital bed.

[0053] The local coil 230 can be placed on the body surface of the detection object and can enter the scanning chamber 210 with the detection object. There can be multiple local coils 230. The multiple local coils 230 can respectively receive the magnetic resonance signals generated during the magnetic resonance detection of the detection object. Each local coil includes multiple antenna units and an amplifier, and the amplifier amplifies the tiny magnetic resonance signals received by the antenna units. The local coil can be placed on the body surface of the detection object and can enter the scanning chamber with the detection object.

[0054] The RF cable 240 is a cable for transmitting RF excitation and / or receiving magnetic resonance signals. The RF cable 240 can connect the coil plug 221 to the local coil 230. The RF cable 240 can be used to transmit signals between the RF coil and other aspects of the magnetic resonance device 200. For example, the RF cable 240 can transmit signals to control the body transmit coil or receive signals from the RF receiver.

[0055] The RF cable 240 can include types such as coaxial RF cables, symmetric RF cables, and helical RF cables.

[0056] In some embodiments, in order to suppress the common-mode current generated on the RF cable 240, a notch filter can be designed on the RF cable 240. In some embodiments, multiple notch filter units can be provided on the RF cable 240 to suppress the common-mode current. For more descriptions of the RF cable 240, see the relevant descriptions later.

[0057] In some embodiments, the magnetic resonance device 200 can also include a spectrometer system, a control system, etc. The spectrometer system is the central control system of the magnetic resonance device 200, responsible for generating, controlling each link of the sequence, and coordinating the operation, such as the RF transmission timing, the gradient application timing in cooperation, etc. Signal acquisition, data processing, and image reconstruction are mainly completed by the spectrometer system. The control system includes a main control computer, image display, examination bed, and RF shielding, magnetic shielding, cooling system, etc., to control and manage the process of obtaining magnetic resonance images.

[0058] Figure 3 It is a schematic structural diagram of an RF cable shown in some embodiments of this specification.

[0059] In some embodiments, as Figure 3 shown, the RF cable 240 includes a cable body 310, multiple notch filter units 320, an insulating member 330, and an outer sheath 340. Among them, the outer sheath 340 is sleeved outside the cable body 310; the multiple notch filter units 320 are arranged between the outer sheath 340 and the cable body 310 and are spaced along the axial direction of the cable body 310; any two adjacent notch filter units 320 are separated by the insulating member 330.

[0060] The cable body 310 is a cable used to transmit signals in the RF cable 240. The cable body 310 may be composed of at least one cable. The number and function of the cables constituting the cable body 310 may be set according to actual needs.

[0061] The wave trap unit 320 is a unit structure that constitutes the wave trap. The wave trap provided by the present technical solution is used to be connected to the cable body 310 to suppress the common mode current on the cable body 310 and reduce the impact on the local radio frequency field. When the wave trap unit 320 is sleeved on the cable body 310, high impedance is applied to the cable body 310 through coupling, which can hinder the common mode current from passing through the radio frequency cable 240.

[0062] In some embodiments, a plurality of wave trap units 320 are disposed on the cable body 310, and the plurality of wave trap units 320 are spaced apart along the axial direction of the cable body 310. In some embodiments, the plurality of wave trap units 320 may be equally spaced apart in the axial direction of the cable body 310. In other embodiments, the plurality of wave trap units 320 may also be unequally spaced apart in the axial direction of the cable body 310, which may be arranged according to actual needs.

[0063] In some embodiments, a plurality of wave trap units 320 may be arranged in series along the axial direction of the cable body 310 .

[0064] In some embodiments, the trap unit 320 may be a floating trap. The floating trap may be connected to the cable body 310 by mechanical engagement. Connecting multiple floating traps in series to the cable body 310 does not require cutting the cable, thereby allowing for easy reconfiguration of the position of the floating trap along the cable. The design of multiple trap units 320 in series can be applied to different types of RF cables, and can be completely disassembled and easily installed on any RF cable without affecting any coil parameters, making it easy to manufacture and debug.

[0065] In some embodiments, the wave trap unit 320 may be composed of an inner sleeve, an outer sleeve, and a capacitor. For more information about this structure, see Figure 4 , Figure 5A and Figure 5B and its related description.

[0066] In some embodiments, the wave trap unit 320 may be composed of two coils in a ring-shaped spiral shape and a capacitor. For more information about this structure, see Figure 7 , Figure 8A and Figure 8B and its related description.

[0067] The insulating member 330 is a structure for isolating two adjacent notch filter units 320. The insulating member 330 can be made of insulating materials, such as plastics, ceramics, etc.

[0068] In some embodiments, the insulating member 330 can be an annular structure sleeved on the cable body 310 and disposed between two adjacent notch filter units 320. In some embodiments, the insulating member 330 can be an annular sheet structure or an annular block structure, which can be specifically set according to actual requirements.

[0069] In some embodiments, an insulating member 330 can be provided between every two adjacent notch filter units 320.

[0070] In some embodiments, the insulating member 330 can be a flexible insulating member. The flexible insulating member can be made of flexible insulating materials. For example, the flexible insulating member can be made of materials such as felt and plastics.

[0071] The outer sheath 340 is a structure sleeved outside a plurality of notch filter units 320.

[0072] The outer sheath 340 can be made of any feasible material. For example, the outer sheath 340 can be made of materials such as plastics or rubbers.

[0073] In some embodiments, the outer sheath 340 can be a flexible outer sheath. For example, the outer sheath 340 can be made of flexible materials such as leather and soft packaging materials.

[0074] In some embodiments, the outer sheath 340 can be composed of a multi-layer structure. In some embodiments, the outer sheath 340 can include a wrapping layer and a protective layer. The wrapping layer is located outside the protective layer. The protective layer is directly sleeved outside a plurality of notch filter units 320. In some embodiments, the protective layer can be made of insulating, fireproof, heat-insulating and other materials. For example, the protective layer can be made of felt. In some embodiments, the wrapping layer can be made of soft packaging materials such as leather.

[0075] In some embodiments of this specification, by serially arranging a plurality of notch filter units on a radio frequency cable, the radio frequency cable has better common-mode rejection ability. By providing an insulating member between two adjacent notch filter units, a short circuit phenomenon between two adjacent notch filter units can be prevented. At the same time, the energy can also be dispersed in a plurality of notch filter units to reduce the heat generation of a single notch filter unit and ensure the suppression effect on the common-mode current. Moreover, even if an individual notch filter unit is damaged, it will not affect the suppression effect on the common-mode current. By sleeving an outer sheath on the outermost layer, it can prevent fire and heat insulation; the outer sheath is made of flexible materials, which can effectively improve the touch feel, and at the same time make the radio frequency cable have no protruding structure and have a good degree of bending.

[0076] Figure 4 is a schematic structural diagram of a notch filter unit shown in some embodiments of this specification; Figure 5A is a schematic diagram of a notch filter unit sleeved on a cable main body shown in some embodiments of this specification; Figure 5B is a schematic diagram of a plurality of notch filter units sleeved on a cable main body shown in some embodiments of this specification.

[0077] As Figure 4 , Figure 5A and Figure 5B shown, in some embodiments, the notch filter unit 320 includes an outer sleeve 321, an inner sleeve 322, and a first capacitor 323. Among them, the inner sleeve 322 is sleeved outside the cable main body 310; the outer sleeve 321 is sleeved outside the inner sleeve 322; one end of the first capacitor 323 is electrically connected to the inner sleeve 322, and the other end is electrically connected to the outer sleeve 321.

[0078] The outer sleeve 321 and the inner sleeve 322 are the main structures that make up the notch filter unit 320. Both the outer sleeve 321 and the inner sleeve 322 are hollow cylindrical structures with openings at both ends. Among them, the diameter of the outer sleeve 321 is greater than the diameter of the inner sleeve 322, and the length of the outer sleeve 321 along the axis direction of the cable main body 310 is equal to the length of the inner sleeve 322 along the axis direction of the cable main body 310.

[0079] In some embodiments, the outer sleeve 321 is sleeved outside the inner sleeve 322, and a hollow space is formed between the outer sleeve 321 and the inner sleeve 322.

[0080] In some embodiments, the hollow part of the inner sleeve 322 is used to thread the cable main body 310.

[0081] In some embodiments, the outer sleeve 321 and the inner sleeve 322 can be made of a conductive material. For example, the outer sleeve 321 and the inner sleeve 322 can be made of a metal material, such as a metal material like iron, aluminum, copper, etc.

[0082] In some embodiments, the outer sleeve 321 and the inner sleeve 322 can be electrically connected together through the first capacitor 323. The first capacitor 323 is a capacitor connected to the outer sleeve 321 and the inner sleeve 322. The first capacitor 323 can be a tuning capacitor.

[0083] As Figure 4 and Figure 5AAs shown, one end of the first capacitor 323 is electrically connected to the inner sleeve 322, and the other end is electrically connected to the outer sleeve 321. For example, the positive electrode of the first capacitor 323 can be connected to the inner sleeve 322, and the negative electrode of the first capacitor 323 can be connected to the outer sleeve 321. Another example is that the negative electrode of the first capacitor 323 can be connected to the inner sleeve 322, and the positive electrode of the first capacitor 323 can be connected to the outer sleeve 321.

[0084] There can be multiple first capacitors 323. Preferably, there are 4 first capacitors 323, and the 4 first capacitors 323 can be evenly distributed in the circular ring area formed by the end face of the outer sleeve 321 and the end face of the inner sleeve 322. For example, the included angle between every two of the 4 first capacitors 323 can be 90 degrees.

[0085] In some embodiments, one end of each of the multiple first capacitors 323 is electrically connected to the inner sleeve 322, and the other end is electrically connected to the outer sleeve 321. In some embodiments, the multiple first capacitors 323 can be connected in series or in parallel. By adjusting the objects to which the positive and negative electrodes of the first capacitor 323 are connected, the connection method between the multiple first capacitors 323 can be adjusted. For example, when the positive electrode of each of the multiple first capacitors 323 is connected to the inner sleeve 322 and the negative electrode is connected to the outer sleeve 321, the multiple first capacitors 323 are connected in parallel at this time. When the positive electrode of one of every two adjacent first capacitors among the multiple first capacitors 323 is connected to the inner sleeve 322 and the negative electrode is connected to the outer sleeve 321, and the negative electrode of the other first capacitor is connected to the inner sleeve 322 and the positive electrode is connected to the outer sleeve 321, the multiple first capacitors 323 are connected in series at this time.

[0086] In some embodiments, the notch filter unit 320 can be tuned by adjusting the first capacitor 323. In an AC circuit, the capacitance value of a capacitor changes with the frequency. Therefore, when a capacitor and other components of a circuit form a circuit together, the frequency response of the circuit can be controlled by adjusting the capacitance value of the capacitor.

[0087] As Figure 4 、 Figure 5A and Figure 5B shown, in some embodiments, the notch filter unit 320 further includes a circuit board 324. The circuit board 324 is annular. One end of the inner ring of the circuit board 324 is connected to one end of the inner sleeve 322, and one end of the outer ring of the circuit board 324 is connected to one end of the outer sleeve 321; the first capacitor 323 is arranged on the circuit board 324 to connect to the outer sleeve 321.

[0088] The circuit board 324 is annular, the inner diameter of the circuit board 324 is the same as the diameter of the inner sleeve 322, and the outer diameter of the circuit board 324 is the same as the diameter of the outer sleeve 321.

[0089] In some embodiments, the inner sleeve 322 and the outer sleeve 321 are hollow cylindrical structures with openings at both ends, and the circuit board 324 can be arranged at the end of the same end of the inner sleeve 322 and the outer sleeve 321.

[0090] In some embodiments, the end of the inner sleeve 322 and the end of the outer sleeve 321 can be fixed to the circuit board 324. For example, the end of the inner sleeve 322 and the end of the outer sleeve 321 can be fixed to the circuit board 324 by means of snap connection, welding, etc.

[0091] In some embodiments, the circuit board 324 can include one or two. For example, one circuit board 324 can be arranged at the end of one end of the hollow cylindrical structure formed by the inner sleeve 322 and the outer sleeve 321, or one circuit board 324 can be arranged at each end of the hollow cylindrical structure formed by the inner sleeve 322 and the outer sleeve 321.

[0092] In some embodiments, an annular metal sheet 325 is arranged at one end of the inner sleeve 322 to connect the outer sleeve 321. When one circuit board 324 is arranged at the end of one end of the hollow cylindrical structure formed by the inner sleeve 322 and the outer sleeve 321, an annular metal sheet 325 can also be arranged at the other end of the hollow cylindrical structure formed by the inner sleeve 322 and the outer sleeve 321. The annular metal sheet 325 is used to connect the inner sleeve 322 and the outer sleeve 321 to achieve electrical connection between the inner sleeve 322 and the outer sleeve 321. At the same time, the annular metal sheet 325 can also make the overall structure of the notch filter unit more stable. For example, the inner ring of the annular metal sheet 325 can be connected to the end of one end of the inner sleeve 322, and the outer ring of the annular metal sheet 325 can be connected to the end of one end of the outer sleeve 321.

[0093] In some embodiments, the first capacitor 323 can be welded to the circuit board 324. In some embodiments, preset circuits can be arranged on the circuit board 324 to achieve electrical connection between one end of the first capacitor 323 and the inner sleeve 322, and electrical connection between the other end of the first capacitor 323 and the outer sleeve 321. In some embodiments, preset circuits can be arranged on the circuit board 324 to achieve series or parallel connection of multiple first capacitors 323.

[0094] In some embodiments of this specification, using the outer sleeve and the inner sleeve made of metal material can accelerate heat dissipation and is simpler to manufacture. By adjusting the capacitor, the notch filter unit can be tuned to make the circuit have advantages such as better selectivity, higher gain, and lower noise. By arranging a ring-shaped circuit board, connecting the inner ring of the circuit board to one end of the inner sleeve, and connecting the outer ring of the circuit board to one end of the outer sleeve, the setting of the capacitor can be made more convenient, and the overall structure of the notch filter unit can be made more stable.

[0095] Figure 6A is a schematic structural diagram of an outer sleeve shown in some embodiments of this specification; Figure 6B is a schematic side view of an outer sleeve shown in some embodiments of this specification.

[0096] As Figure 6A , Figure 6B shown, in some embodiments, a plurality of through holes 600 are provided on the outer sleeve 321.

[0097] The through hole 600 refers to a hole formed on the outer sleeve 321.

[0098] In some embodiments, the through holes 600 may be arranged along the radial direction of the outer sleeve 321, but do not penetrate the outer sleeve 321. When the through holes 600 are arranged along the radial direction of the outer sleeve 321, the axial direction of the through holes 600 is the same as the radial direction of the outer sleeve 321. By setting the through holes not to penetrate the outer sleeve, the heat dissipation effect of the outer sleeve can be improved by increasing the heat dissipation area.

[0099] In some embodiments, the through holes 600 may penetrate the outer sleeve 321 along the radial direction of the outer sleeve 321. By setting the through holes to penetrate the outer sleeve, the heat dissipation effect of the outer sleeve can be improved by utilizing air convection.

[0100] In some embodiments of this specification, by providing a plurality of through holes on the outer sleeve, the influence of eddy currents on the outer sleeve can be effectively reduced.

[0101] As Figure 6A , Figure 6B shown, in some embodiments, the plurality of through holes 600 include multiple groups (for example, divided into multiple groups), and each group of through holes 600 is arranged along the circumferential direction of the outer sleeve 321. The multiple groups of through holes 600 are arranged at intervals along the axial direction of the outer sleeve 321, and adjacent two groups of through holes 600 are arranged staggeredly.

[0102] In some embodiments, the geometric centers of the multiple through holes 600 in a group of through holes 600 may be located on the same plane, and this plane is a cross-section of the outer sleeve 321 perpendicular to the axial direction.

[0103] In some embodiments, each group of through holes 600 in the multiple groups of through holes 600 may be arranged at equal intervals along the circumferential direction of the outer sleeve 321. For example, the angle between the geometric centers of every two adjacent through holes 600 in a group of through holes 600 and the geometric center (such as the center of a circle) of the cross-section where the geometric centers of this group of through holes 600 are located is the same. At this time, the multiple through holes 600 in a group of through holes 600 are arranged at equal intervals.

[0104] In some embodiments, the cross-sections where the geometric centers of different groups of through-holes 600 are located may be spaced apart axially of the outer sleeve 321, so that multiple groups of through-holes 600 can be arranged axially along the outer sleeve 321. The distance between the cross-sections where the geometric centers of two adjacent groups of through-holes 600 are located is the same, so that multiple groups of through-holes 600 can be equally spaced axially along the outer sleeve 321.

[0105] In some embodiments, the situation where two adjacent groups of through-holes 600 are staggeredly arranged may include: the connection line between the geometric center of any one of the multiple through-holes 600 in one group of through-holes 600 and the geometric center of any one of the multiple through-holes 600 in the adjacent other group of through-holes 600 is not parallel to the axial direction of the outer sleeve 321.

[0106] It should be noted that the current direction is the axial direction of the outer sleeve 321. In some embodiments of this specification, by opening a plurality of through-holes distributed staggeredly on the outer sleeve, that is, when two adjacent groups of through-holes are staggeredly arranged, the staggeredly arranged through-holes will cut off the current transmitted along the axial direction of the outer sleeve, so that the current is transmitted from the gaps between the through-holes, and thus the path of the current (such as Figure 6B the current I shown) on the outer sleeve can be lengthened, effectively reducing the heat generation of the outer sleeve.

[0107] Figure 7 is a schematic structural diagram of a notch filter unit shown in some other embodiments of this specification; Figure 8A is a schematic diagram of the notch filter unit sleeved on the cable body shown in some other embodiments of this specification;

[0108] Figure 8B is a schematic diagram of a plurality of notch filter units sleeved on the cable body shown in some other embodiments of this specification.

[0109] As Figure 7 、 Figure 8A shown, in some embodiments, the notch filter unit 320 includes a first coil 326 and a second coil 327. Among them, the first coil 326 and the second coil 327 are configured as annular spirals; there are breaks 328 on the first coil 326 and the second coil 327, and second capacitors 329 are arranged on both the first coil 326 and the second coil 327; the winding directions of the first coil 326 and the second coil 327 are opposite or reverse, the first coil 326 and the second coil 327 are overlapped and placed, and there is a first channel inside the first coil 326 and the second coil 327, and the first channel allows the cable body 310 to pass through.

[0110] The first coil 326 and the second coil 327 may be wound by insulated wires.

[0111] In some embodiments, the inner diameters of the rings formed by the first coil 326 and the second coil 327 respectively can be set according to the diameter of the cable body 310.

[0112] The second capacitor 329 can be a tuning capacitor. The first coil 326 and the second coil 327 respectively form a disconnected coil with the second capacitor 329.

[0113] In some embodiments, the number of the second capacitors 329 on the first coil 326 and the second coil 327 can be one, two, three or even more.

[0114] By arranging the first coil 326 and the second coil 327 into an annular spiral structure, they can be regarded as inductors, and are connected in parallel with the second capacitor 329 to form a parallel resonance circuit, generating a high impedance. When the notch filter unit 320 is sleeved on the cable body 310, the high impedance acts on the cable body 310 through coupling, which can prevent the common-mode current from passing through the RF cable 240.

[0115] By arranging the first coil 326 and the second coil 327 in opposite winding directions, when a common-mode current is generated in the cable body 310, a magnetic field in the same direction distributed along the circumferential direction of the cable body 310 will be generated inside the first coil 326 and the second coil 327. Since the winding directions are opposite, the current directions on the first coil 326 and the second coil 327 are opposite. Therefore, the magnetic fields outside the first coil 326 and the second coil 327 cancel each other out, reducing the influence on the local RF field, while the magnetic fields inside them are superimposed on each other, generating a current in the axial direction of the cable opposite to the direction of the common-mode current to cancel out the common-mode current.

[0116] By overlapping the first coil 326 and the second coil 327, a mutual inductance is formed between the first coil 326 and the second coil 327, so that the energy coupled from the cable body 310 into the notch filter 100 is divided into two current paths, reducing the heat generation of the notch filter unit 320 and making the notch filter unit 320 smaller in volume and lighter in weight. Therefore, with the notch filter unit 320 having the above structural form, while improving the effect of suppressing the common-mode current in the cable body 310, the notch filter unit 320 is made smaller in volume and lighter in weight.

[0117] When there are breaks 328 in the first coil 326 and the second coil 327, overlapping the first coil 326 and the second coil 327 can generate a distributed capacitance, which forms a parallel resonance with the equivalent inductances corresponding to the first coil 326 and the second coil 327 respectively. Since there are breaks 328 in the first coil 326 and the second coil 327, the first coil 326 and the second coil 327 can be regarded as two equivalent inductances connected in series.

[0118] In some embodiments, further, in order to reduce the influence of the magnetic field leaked from the solenoid coil on the radio frequency field, a shielding cover can be provided outside the notch filter unit 320, so as to further reduce the influence on the local radio frequency field. Among them, the shielding cover can be made of copper foil and wrapped outside the spiral coil.

[0119] In some embodiments, the first coil 326 and the second coil 327 are overlapped and arranged in opposite winding directions, which can make the first coil 326 and the second coil 327 form a spiral staggered structure. As Figure 8B shown, in some embodiments, there are multiple spiral staggered structures, and the multiple spiral staggered structures are arranged at intervals along the axis of the cable body 310. By arranging multiple spiral staggered structures on the cable body 310, the RF cable 240 has good common-mode rejection ability, can be applied to different models of RF cables 240, and can be completely disassembled, and can be easily installed on any RF cable 240 without affecting any coil parameters, which is convenient for production and debugging.

[0120] In some embodiments, an insulating member 330 can be provided between two adjacent spiral staggered structures to isolate the two adjacent spiral staggered structures to prevent short circuit between the spiral staggered structures. Doing so can also disperse the energy in multiple spiral staggered structures to reduce the heat generation of a single spiral staggered structure. Moreover, even if an individual spiral staggered structure is damaged, it will not affect the suppression effect on the common-mode current. Adopting the above structure has the advantages of reducing the heat generation of a single spiral staggered structure and ensuring the suppression effect on the common-mode current. The spiral staggered structure in this embodiment can be regarded as a notch filter unit.

[0121] Figure 9 is another schematic structural diagram of an RF cable according to some embodiments of this specification; Figure 10A is a schematic structural diagram of an end connection assembly according to some embodiments of this specification; Figure 10B is a connection schematic diagram of an end connection assembly according to some embodiments of this specification.

[0122] As Figure 3 、 Figure 9 、 Figure 10A and Figure 10B shown, the RF cable 240 further includes an end connection assembly 350. The end connection assembly 350 includes a connector 351 and a housing 352. The connector 351 connects the cable body 310, and the housing 352 is connected to the connector 351 and covers the connector 351.

[0123] The end connection assembly 350 can enable a better connection between the RF cable 240 and an external electrical connection structure. For example, the end connection assembly 350 can enable a better connection between the RF cable 240 and an external plug or other structure.

[0124] The connecting member 351 in the end connection assembly 350 can enable a better connection between the RF cable 240 and an external electrical connection structure. For example, by connecting the connecting member 351 of the end connection assembly 350 to an external plug or other structure, the end connection assembly 350 can be connected to the external plug or other structure.

[0125] The connecting member 351 can be in various structural forms. For example, the connecting member 351 can be a cylindrical structure with a snap structure, a hook structure, etc.

[0126] In some embodiments, the outer sheath 340 can be sleeved on part or all of the connecting member 351 and fixedly connected to the connecting member 351 through a snap structure, a hook structure, etc.

[0127] In some embodiments, the connecting member 351 includes a second channel (not shown in the figure) and a positioning wire 353. The cable body 310 includes a signal transmission line (not shown in the figure) and a tensile wire (not shown in the figure). The positioning wire 353 is connected to the tensile wire, and the signal transmission line passes through the second channel. By providing the tensile wire, the tensile strength of the cable body 310 can be effectively enhanced.

[0128] The second channel allows the signal transmission line in the cable body 310 to pass through. The connecting member 351 can be a hollow cylindrical structure, and the second channel is provided in the hollow area of the connecting member 351.

[0129] The positioning wire 353 is a structure for fixing the cable body 310 to the connecting member 351. By connecting the tensile wire of the cable body 310 to the positioning wire 353, the cable body 310 can be fixed to the connecting member 351. Among them, the connection method between the tensile wire and the positioning wire 353 includes but is not limited to welding, winding connection, stitching connection, etc.

[0130] The housing 352 is a structure sleeved on the outside of the connecting member 351 and a part of the outer sheath 340 connected to the connecting member 351.

[0131] In some embodiments, the inner diameter of the housing 352 is greater than the outer diameter of the connecting member 351 and greater than the outer diameter of a part of the outer sheath 340 connected to the connecting member 351.

[0132] In some embodiments, the housing 352 can be composed of two hollow cylindrical structures with different inner diameters. Among them, the hollow cylindrical structure with a smaller inner diameter is sleeved on the connecting member 351, and the hollow cylindrical structure with a larger inner diameter is sleeved on a part of the outer sheath 340 connected to the connecting member 351.

[0133] In some embodiments, the outer shell 352 can be assembled to the connecting member 351 in a variety of ways so as to be sleeved on the outside of the connecting member 351 and the partial outer sheath 340 connected to the connecting member 351. For example, the hollow cylindrical structure with a smaller inner diameter in the outer shell 352 can be fixedly connected to the connecting member 351 by any feasible means such as snap connection, screw connection, riveting, etc.

[0134] In some embodiments of this specification, by providing an end connection assembly connected to the outer sheath, it is beneficial to connect a radio frequency cable to an external plug to form a complete cable. By connecting the wire originally used for tensile strength to the positioning wire, the connection between the cable body and the end connection assembly can be achieved without introducing other structures. By providing an outer shell sleeved on the connecting member 351 and the partial outer sheath 340 connected to the connecting member 351, the connection area between the connecting member and the outer sheath can be shielded, such as shielding the stitches between the tensile wire and the positioning wire, protecting the connection position between the connecting member and the outer sheath, and making the connection between the connecting member and the outer sheath more stable.

[0135] It should be noted that the beneficial effects that may be produced by different embodiments are different. In different embodiments, the beneficial effects that may be produced can be any one or several combinations of the above, or any other beneficial effects that may be obtained.

[0136] The basic concepts have been described above. Obviously, for those skilled in the art, the above detailed disclosure is only an example and does not constitute a limitation to this specification. Although not explicitly stated here, those skilled in the art may make various modifications, improvements, and corrections to this specification. Such modifications, improvements, and corrections are proposed in this specification, so such modifications, improvements, and corrections still belong to the scope of the exemplary embodiments of this specification.

[0137] Finally, it should be understood that the embodiments described in this specification are only used to illustrate the principles of the embodiments of this specification. Other deformations may also belong to the scope of this specification. Therefore, by way of example and not limitation, alternative configurations of the embodiments of this specification can be regarded as consistent with the teachings of this specification. Accordingly, the embodiments of this specification are not limited to the embodiments explicitly introduced and described in this specification.

Claims

1. A radio frequency cable for a magnetic resonance device, characterized in that, The radio frequency cable (240) includes: a cable body (310); an outer sheath (340) sleeved outside the cable body (310); a plurality of trap units (320) disposed between the outer sheath (340) and the cable body (310) and spaced along the axial direction of the cable body (310); an insulating member (330), and any two adjacent trap units (320) are separated by the insulating member (330).

2. The RF cable according to claim 1, wherein The insulating member (330) is a flexible insulating member, and the outer sheath (340) is a flexible outer sheath.

3. The RF cable according to claim 1, characterized in that, The trap unit (320) includes: a first coil (326) configured in an annular spiral shape; a second coil (327) configured in an annular spiral shape; a break (328) is provided on the first coil (326) and the second coil (327), and a second capacitor (329) is provided on both the first coil (326) and the second coil (327); The winding directions of the first coil (326) and the second coil (327) are opposite or the same. The first coil (326) and the second coil (327) are overlapped and placed, and a first channel is formed inside the first coil (326) and the second coil (327), and the first channel allows the cable body (310) to pass through.

4. The RF cable according to claim 1, characterized in that, The trap unit (320) includes: an inner sleeve (322) sleeved outside the cable body (310); an outer sleeve (321) sleeved outside the inner sleeve (322); a first capacitor (323), one end of the first capacitor (323) is electrically connected to the inner sleeve (322), and the other end is electrically connected to the outer sleeve (321).

5. The RF cable according to claim 4, wherein The trap unit (320) further includes a circuit board (324), the circuit board (324) is in a ring shape, the inner ring of the circuit board (324) is connected to one end of the inner sleeve (322), and the outer ring of the circuit board (324) is connected to one end of the outer sleeve (321); The first capacitor (323) is disposed on the circuit board (324).

6. The RF cable according to claim 4, wherein A plurality of through holes (600) are provided on the outer sleeve (321). The plurality of through holes (600) form multiple groups, and each group of through holes (600) is arranged along the circumferential direction of the outer sleeve (321). The multiple groups of through holes (600) are spaced along the axial direction of the outer sleeve (321), and two adjacent groups of through holes (600) are arranged staggeredly.

7. The RF cable according to claim 1, wherein The radio frequency cable (240) further includes an end connection assembly (350). The end connection assembly (350) includes a connector (351) and a housing (352). The connector (351) connects the cable body (310), and the housing (352) is connected to the connector (351) and covers the connector (351).

8. The RF cable according to claim 7, characterized in that, The connector (351) includes a second channel and a positioning wire (353). The cable body (310) includes a signal transmission line and a tensile wire. The positioning wire (353) is connected to the tensile wire, and the signal transmission line passes through the second channel.

9. A magnetic resonance device, characterized in that, Comprising: A scanner (210) that forms a scanning cavity capable of accommodating a detection object; A hospital bed (220) coupled to the scanner (210), the hospital bed (220) being capable of carrying the detection object and having a coil plug (221) provided thereon; A local coil (230) that can be placed on the body surface of the detection object and can enter the scanning cavity with the detection object; A radio frequency cable (240) connecting the coil plug (221) and the local coil (230); The radio frequency cable (240) includes: A cable body (310); An outer sheath (340) sleeved outside the cable body (310); A plurality of notch filter units (320) provided between the outer sheath (340) and the cable body (310) and spaced along the axial direction of the cable body (310); An insulating member (330) separating any two adjacent notch filter units (320) from each other.

10. The magnetic resonance device according to claim 9, characterized in that, The notch filter unit (320) includes: An inner sleeve (322) sleeved outside the cable body (310); An outer sleeve (321) sleeved outside the inner sleeve (322); One end of the inner sleeve (322) is provided with an annular metal sheet to connect the outer sleeve (321); The other end of the inner sleeve (322) is provided with a circuit board, and a first capacitor is provided on the circuit board to connect the outer sleeve (321).

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